Project Report

On

SOLAR BASED WATER SPRAYER

SUBMITTED BY:

SUBMITTED TO:

GURU NANAK DEV ENGINEERING COLLEGE

LUDHIANA

CANDIDATE DEACLARATION

I hereby affirm that I undertaken the project report on the water sprayer during the period in the partial fulfillment of requirement of the award of B.Tech. (Electrical Engineering) at PUNJAB TECHNICAL UNIVERSITY, JALANDHAR.

The work which is being presented report submitted to the Department of Electrical Engineering at Bhutta College of Engineering & Technology, Ludhiana is an authentic record of the project work.

The project report examination of________________________has been held on

______________and accepted.

Signature of internal Examiner                            Signature of External Examiner

ACKNOWLEDGEMENT

Many individual have proudly influenced us during our undergraduate studies (B.Tech.) at BCET, LUDHIANA and it is pleasure to acknowledge their guidance and support In college, I learned many things, like, the project training is mainly aimed at enabling the student to apply their theoretical knowledge to practical as “The theory is to know how and practical to do how” and to appreciate the limitation of knowledge gained in the class room to practical situation and to appreciate the importance of discipline, punctuality, team work, sense of responsibility, money, value of time, dignity of labour.

I will like to express my gratitude towards Er. Chamandeep Kaurwho took keen interest in our project,Who helped me in every possible way and is source of inspiration for all the group members.

I would also like to thank to all Electrical Department of BCET Ludhiana who motivated me to complete our project with enthusiasm and hard work. He helped every time when I need

GURPREET SINGH

JATINDER PAL SINGH

AMRINDER SINGH

Objective:

The main objective of this project is to make a spray pump which can be operated on both AC and DC supply voltages.When AC source is present we operate it on AC voltage.When AC is OFF then we will take advantage of DC supply.we will just connect a DC battery of 12 volt to DC pump.DC pump will get on and spray pump will start working.

Specifications

Battery 12 volt, 2.5A

DC Pump 12 Volt,3A

Sprat Tank 20 lts

Spray tank nozzle

Connecting wires

Tabole of Content

Title                                                                                                Page No.

Specifications                                                                                                       5

Itroduction                                                                                                   6

Diagram                                                                                                              7

Chapter 1

Sprinkler                                                                                                           8

chapter 2

Nozzle                                                                                                                10

Chapter 3

Sprayer Nozzle

chapter 4    

Pump                                                                                                            

Bibliography                                                                                                       56

Introduction:

In this project we will make a spray pump operated with AC and DC supply Both.Project is tough  for us because it contain some electrical parts and mechanical parts.We used 12v DC pump for water spray.DC Pump is connected to DC supply source.for this purpose we use a DC battery.which is of 12 volts and 2.5 A.when Dc pump is connected to positive and negative terminal of battery,then pump will get on.It will start spray through nozzle.we have connected a switch between Pump and battery to on and off the spray pump.in this project we have connected a AC pump also.which is operated on AC supply of 220 volts.AC pump is of 220c AC and 1A.we will connect AC pump to AC supply through Power lead.pump will get on.It will start spray the liquid through nozzle.In This way we can spray using Both AC and Supply Through AC and DC Pumps.

Diagram

Chapter 1

Sprinklers

Sprinklers that spray in a fixed pattern are generally called sprays or spray heads. Sprays are not usually designed to operate at pressures above 30 lbf/in² (200 kPa) (30psi “Pounds per square inch”), due to misting problems that may develop.

Higher pressure sprinklers that themselves move in a circle are driven by a ball drive, gear drive, or impact mechanism (impact sprinklers). These can be designed to rotate in a full or partial circle.

Rainguns are similar to impact sprinkler, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). In addition to irrigation, guns are used for industrial applications such as dust suppression and logging.

Many irrigation sprinklers are buried in the ground along with their supporting plumbing, although above ground and moving sprinklers are also common. Most irrigation sprinklers operate through electric and hydraulic technology and are grouped together in zones that can be collectively turned on and off by actuating a solenoid-controlled valve.

An impact sprinkler head in action

Residential sprinklers  This section requires expansion.

Home lawn sprinklers vary widely in their size, cost, and complexity. They include impact sprinklers, oscillating sprinklers, drip sprinklers, and underground sprinkler systems. Small sprinklers are available at home and garden stores or hardware stores for small costs. These are often attached to an outdoor water faucet and are placed only temporarily. Other systems may be professionally installed permanently in the ground and are attached permanently to a home’s plumbing system.

Permanently installed system may often operate on timers or other automated processes. They are occasionally installed with retractable heads for aesthetic and practical reasons (making damage during lawn mowing or other maintenance less likely). These often are programed to operate at certain times of day or on some other schedule.

1.1 Underground sprinklers

Underground sprinklers function through means of basic electronic and hydrolic technology. This valve and all of the sprinklers that will be activated by this valve are known as a zone. Upon activation, the solenoid, which sits on top of the valve is magnetized lifting a small stainless steel plunger in its center. By doing this, the activated (or raised) plunger allows air to escape from the top of a rubber diaphragm located in the center of the valve. Water that has been charged and waiting on the bottom of this same diaphragm now has the higher pressure and lifts the diaphragm. This pressurized water is then allowed to escape down stream of the valve through a series of pipes, usually made of PVC. At the end of these pipes and flush to ground level (typically) are pre measured and spaced out sprinklers. These sprinklers can be fixed spray heads that have a set pattern and generally spray between 1.5-2m (7–15 ft.), full rotating sprinklers that can spray a broken stream of water from 6-12m (20–40 ft.), or small drip emitters that release a slow, steady drip of water on more delicate plants such as flowers and shrubs.

1.2 Sprinkler use

Most irrigation sprinklers are used as part of a sprinkler system, consisting of various plumbing parts, piping and control equipment. Piping is connected to the water source via plumbing fittings and the control system opens and closes valves to provide water on a schedule. The control provided varies depending on the equipment used; some systems are fully automated and even compensate for rain, runoff and evaporation, while others require much more user attention for the same effectiveness.

Outdoor sprinkler systems are sometimes used as a deterrent against homeless people. For example, the city of Los Angeles installed an elaborate overhead sprinkler system in a downtown park along lower Fifth Street. This sprinkler system was programmed to drench unsuspecting sleepers at random times during the night. Local businessmen soon copied this system in an effort to drive homeless people away from public sidewalks adjacent to their businesses.

Chapter 2

Nozzle

A nozzle is a device designed to control the direction or characteristics of a fluid flow (especially to increase velocity) as it exits (or enters) an enclosed chamber or pipe.

A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas). Nozzles are frequently used to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that emerges from them. In nozzle velocity of fluid increases on the expense of its pressure energy.

2.1 Jet

A gas jet, fluid jet, or hydro jet is a nozzle intended to eject gas or fluid in a coherent stream into a surrounding medium. Gas jets are commonly found in gas stoves, ovens, or barbecues. Gas jets were commonly used for light before the development of electric light. Other types of fluid jets are found in carburetors, where smooth calibrated orifices are used to regulate the flow of fuel into an engine, and in jacuzzis or spas.

Another specialized jet is the laminar jet. This is a water jet that contains devices to smooth out the pressure and flow, and gives laminar flow, as its name suggests. This gives better results for fountains.

The foam jet is another type of jet which uses foam instead of a gas or fluid.

Nozzles used for feeding hot blast into a blast furnace or forge are called tuyeres.

Jet nozzles are also use in large rooms where the distribution of air via ceiling diffusers is not possible or not practical. Diffusers that uses jet nozzles are called jet diffuser where it will be arranged in the side wall areas in order to distribute air. When the temperature difference between the supply air and the room air changes, the supply air stream is deflected upwards, to supply warm air, or downwards, to supply cold air.

2.2 High velocity

  

A rocket nozzle

 a convergent nozzle to expand supersonically externally. The shape of the divergent section also ensures that the direction of the escaping gases is directly backwards, as any sideways component would not contribute to thrust.

2.3 Propelling

 

Frequently, the goal of a nozzle is to increase the kinetic energy of the flowing medium at the expense of its pressure and internal energy.

• Nozzles can be described as convergent (narrowing down from a wide diameter to a smaller diameter in the direction of the flow) ordivergent (expanding from a smaller diameter to a larger one). A de Laval nozzle has a convergent section followed by a divergent section and is often called a convergent-divergent nozzle (“con-di nozzle”).
• Convergent nozzles accelerate subsonic fluids. If the nozzle pressure ratio is high enough, then the flow will reach sonic velocity at the narrowest point (i.e. the nozzle throat). In this situation, the nozzle is said to be choked.
• Increasing the nozzle pressure ratio further will not increase the throat Mach number above one. Downstream (i.e. external to the nozzle) the flow is free to expand to supersonic velocities; however Mach 1 can be a very high speed for a hot gas because the speed of soundvaries as the square root of absolute temperature. This fact is used extensively in rocketry where hypersonic flows are required and where propellant mixtures are deliberately chosen to further increase the sonic speed.
• Divergent nozzles slow fluids if the flow is subsonic, but they accelerate sonic or supersonic fluids.
• Convergent-divergent nozzles can therefore accelerate fluids that have choked in the convergent section to supersonic speeds. This CD process is more efficient than allowing

Propelling nozzle

A jet exhaust produces a net thrust from the energy obtained from combusting fuel which is added to the inducted air. This hot air passes through a high speed nozzle, apropelling nozzle, which enormously increases its kinetic energy.[2]

Increasing exhaust velocity increases thrust for a given mass flow, but matching the exhaust velocity to the air speed provides the best energy efficiency. However, momentum considerations prevent jet aircraft from maintaining velocity while exceeding their exhaust jet speed. The engines of supersonic jet aircraft, such as those of fighters and SSTaircraft (e.g. Concorde) almost always achieve the high exhaust speeds necessary for supersonic flight by using a CD nozzle despite weight and cost penalties; conversely, subsonic jet engines employ relatively low, subsonic, exhaust velocities and therefore employ simple convergent nozzle, or even bypass nozzles at even lower speeds.

Rocket motors maximise thrust and exhaust velocity by using convergent-divergent nozzles with very large area ratios and therefore extremely high pressure ratios. Mass flow is at a premium because all the propulsive mass is carried with vehicle, and very high exhaust speeds are desirable.

2.4 Magnetic

Magnetic nozzles have also been proposed for some types of propulsion, such as VASIMR, in which the flow of plasma is directed by magnetic fields instead of walls made of solid matter.

2.5 Spray

Many nozzles produce a very fine spray of liquids.

• Atomizer nozzles are used for spray painting, perfumes, carburetors for internal combustion engines, spray on deodorants, antiperspirants and many other similar uses.
• Air-Aspirating Nozzle uses an opening in the cone shaped nozzle to inject air into a stream of water based foam (CAFS/AFFF/FFFP) to make the concentrate “foam up”. Most commonly found on foam extinguishers and foam handlines.
• Swirl nozzles inject the liquid in tangentially, and it spirals into the center and then exits through the central hole. Due to the vortexing this causes the spray to come out in a cone shape.

2.6 Vacuum

Vacuum cleaner nozzles come in several different shapes. Vacuum Nozzles are used in vacuum cleaners.

2.7 Shaping

Some nozzles are shaped to produce a stream that is of a particular shape. For example, extrusion molding is a way of producing lengths of metals or plastics or other materials with a particular cross-section. This nozzle is typically referred to as a die.

Chapter 3

 Sprayer Nozzles

The proper selection of a nozzle type and size is essential for proper pesticide application. This publication covers nozzle description, recommended uses, selection of the proper nozzle type, and the .ounce. calibration method. A listing of nozzle manufacturers also is included.The proper selection of a nozzle type and size is essential for proper pesticide application. The nozzle is a major factor in determining the amount of spray applied to an area, the uniformity of application, the coverage obtained on the target surface, and the amount of potential drift.Nozzles break the liquid into droplets, form the spray pattern, and propel the droplets in the proper direction. Nozzles determine the amount of spray volume at a given operating pressure, travel speed, and spacing. Drift can be minimized by selecting nozzles that produce the largest droplet size while providing adequate coverage at the intended application rate and pressure.Minimizing drift is especially important for herbicides.

Nozzle Description

Nozzle types commonly used in low-pressure agricultural sprayers include flat-fan, flood, raindrop, hollow-cone, fullcone,and others. Special features, or subtypes such as .extended range,. are available for some nozzle types.

Flat-fan

Flat-fan nozzles are widely used for broadcast spraying of herbicides. These nozzles produce a tapered-edge, flatfan spray pattern . These nozzles have several subtypes, such as standard flat-fan, even flat-fan, low pressure flat-fan, extended-range flat-fan, and some special types such as off-center flat-fans and twin-orifice flat-fans.The standard flat-fan normally operates between 30  and 60 pounds per square inch (psi), with an ideal range between 30 and 40 psi. The even flat-fan nozzles  apply uniform coverage across the entire width of the spray pattern. They are used for banding pesticide over the row and should not be used for broadcast applications. The band width can be controlled with the nozzle height and the spray angle. The low pressure flat-fan develops a normal flat-fan angle and spray pattern at operating pressures between 15 and 20 psi. Lower pressures result in larger droplets and less drift, but a low-pressure nozzle produces a smaller droplet at the same pressure as a standard nozzle.

The extended range flat-fan provides excellent drift control when operated between 15 and 25 ps uniform distribution of a flat-fan nozzle and wants lower operating pressures for drift control. Since extended range nozzles have an excellent spray distribution over a wide range of pressures (15-60 psi), they are ideal for sprayers equipped with flow controllers. The special feature flat-fan nozzle, such as the offcenter flat-fan, is used for boom end nozzles so a wide swath projection is obtained. The twin-orifice flat-fan produces two spray patterns . one angled 30 degrees forward, and the other directed 30 degrees backward.The droplets are small due to the atomizing by two smaller orifices. The two spray directions and smaller droplets improve coverage and penetration, a plus when applying postemergence contact herbicides. To produce fine droplets, the twin-orifice usually operates between 30 and 60 psi. Flat-fan nozzles are available in several spray angles. The most common spray angles are 65, 73, 80, and 110 degrees. Recommended nozzle heights for flat-fan nozzles during broadcast application are given in Table I. Figures 1A and 1B illustrate two spray overlap percentages. Figure 1C illustrates proper spray pattern. The spray pattern will be uneven if nozzles are not aligned properly on the spray boom. Rotate nozzles about ten degrees from the axis of the boom to prevent droplets from adjacent nozzles from touching but still allow for proper overlap of the spray pattern. The correct nozzle height is measured from the nozzle to the target, which may be the top of the ground, growing canopy, or stubble. Use 110-degree nozzles when booms are at lower heights and 80-degree nozzles when booms are higher. Although wide-angle nozzles produce smaller droplets that are more prone to drift, the reduction of boom height reduces the drift potential more than droplet size. The nozzle spacing and orientation should provide for 100 percent overlap and target height. Nozzles should not be oriented more than 30 degrees from vertical. The following are examples of nozzle numbering systems by two manufacturers. Spraying Systems Company* identifies its flat-fan nozzles with a four or five digit number. The first numbers are the spray angle, and the other numbers signify the discharge rate at rated pressure. For example, an 8005 has an 80-degree spray angle and will apply 0.5 gallons per minute (GPM) at rated pressure of 40 psi. An 11002 nozzle has a 110-degree spray angle and will apply 0.2 GPM at rated pressure of 40 psi. Additional designations are .SS. (stainless steel), .HSS. (hardened stainless steel), and .VS. (color-coded stainless steel). Delevan* flat-fan nozzles are identified by .LF. or .LF-R,. which reflect the standard and extended range flat-fan nozzles. The first numbers are the spray angle followed by a dash and then the discharge rate at rated pressure. For example, an LF80-5R is an extended range nozzle with an 80-degree spray angle and will apply 0.5 GPM at the rated pressure of 40 psi.

3.1 Flood

Flood nozzles  are popular for applying suspension fertilizers where clogging is a potential problem.These nozzles produce large droplets at pressures of 10 to 25 psi. The nozzles should be spaced less than 60 inches. The nozzle orientation should be set for 100 percent overlap. These nozzles are generally not suited for contact herbicide applications. Nozzle spacing between 30 and 40 inches produces the best spray patterns. Pressure influences spray patterns of flooding nozzles more than flat-fan nozzles. However, the spray pattern is not as uniform as with the flat-fan nozzles, and special attention to nozzle orientation and correct overlap is critical. Other than fertilizer suspensions, these nozzles are most often used with soil-incorporated herbicides with spray kits mounted on tillage implements. Flooding nozzles are designated .TK. by Spraying Systems and .D. by Delavan. The value following the letters is the flow rate times 10 at rated pressure of 10 psi. For example, TK-SS2 or D-2 are flood nozzles that apply 0.2 GPM at 10 psi.

3.2 Raindrop

Raindrop nozzles produce large drops in a hollow-cone pattern at pressures from 20 to 50 psi. The .RA. Raindrop nozzles are used for herbicide incorporation and are usually mounted on tillage implements. When used for broadcast application, nozzles should be oriented 30 degrees from the horizontal. The spray patterns should be overlapped 100 percent to obtain uniform distribution. These nozzles are not satisfactory for postemergence or non-incorporated herbicides because the droplet size is too large.

3.3 Hollow-cone

Hollow-cone nozzles  generally are used to apply insecticides or fungicides to field crops when foliage penetration and complete coverage of the leaf surface is required. These nozzles operate in a pressure range from 40 to 100 psi. Spray drift potential is higher from hollow-cone nozzles than from other nozzles due to the small droplets produced. Generally, this type of nozzle should not be used to apply herbicides.

3.4 Full-cone

The wide-angle, full-cone nozzles are a good choice if drift is a concern because they produce larger droplets than flood nozzles. Full-cone nozzles usually are recommended over flood nozzles for soil-incorporated herbicides. Full-cone nozzles operate between a pressure range of 15

to 40 psi and are ideal for sprayers equipped with flow controllers.

3.5 Fine Hollow-cone

The Cone-Jet (Spray Systems) and WRW-Whirl Rain (Delavan) are wide-angle (80-120 degrees), hollow-cone nozzles. These nozzles are used for postemergence contact  herbicides where a finely atomized spray is used for complete coverage of plants or weeds.

3.6 Nozzle Materials

Nozzles can be made from several materials. The most common are brass, nylon, stainless steel, hardened stainless steel, tungsten carbide, and ceramic. Ceramic and tungsten carbide nozzles are very long-wearing and extremely corrosion- resistant. Stainless steel nozzles last longer than brass or nylon and generally produce a more uniform pattern over an extended time period. Nylon nozzles with stainless steel or hardened stainless steel inserts offer an alternative to solid stainless steel nozzles at a reduced cost. Thermoplastic nozzles have good abrasion resistance, but swelling can occur with some chemicals, and they are easily damaged when cleaned. Nozzles made from hard materials cost more initially, but in the long run, they pay for themselves because of long-lasting properties. Do not mix nozzles of different materials, types, spray angles, or spray volumes on the same spray boom. A mixture of nozzles produces uneven spray distribution.

3.7 Nozzle Screens

To prevent plugging and excessive wear of the nozzles,always use screens  to remove large particles from the spray mixture, except when spraying very large volumes. At low rates, use 100-mesh screens. When using higher rates or applying wettable powders, use the 50-mesh size; check the manufacturer.s recommendations for the specific nozzle. Smaller mesh screens may plug more easily and therefore require more frequent cleaning. Some screenshave a ball check valve to prevent drip when the sprayer boom is turned off . These are useful if you stop in the field since excessive residues may damage the succeeding crop. Another available anti-drip device is a diaphragm check valve (Figure 5). This valve allows the nozzle tip to be changed without letting spray material leak from the boom.Also, the diaphragm helps to protect the device from chemical corrosion which could cause a check valve to fail.

Sprayer Calibration with the .Ounce.

Method

1. Use the chart below for distance to drive in the field.Use nozzle spacing for booms. For directed and band rigs,use the row spacing.

2. Set throttle for spraying and operate all equipment.Note seconds required to drive measured distance.

3. Catch spray for the noted time in Step 2 in container marked in ounces (a calibrated bottle or measuring cup).If boom, catch spray from one nozzle during noted time.On directed rigs, catch spray from all nozzles per row for

noted time.

4. Nozzle or nozzle group output in ounces equals gallons per acre actually applied.

5. Repeat for each nozzle to assure uniform distribution.

Row Width Row Width

or Nozzle Distance or Nozzle Distance

Spacing (IN) (FT) Spacing (IN) (FT)

40 102 26 157

38 107 24 170

36 113 22 185

34 120 20 204

32 127 18 227

30 136 16 255

28 146 14 291

Replacing Nozzle Tips

Worn nozzles increase application rates and change distribution patterns. The result is poor pest control, crop damage, residue problems, and increased costs. A check of the boom sprayer assures that each tip is delivering an identical volume of spray in a smooth pattern with no heavy streams or blank areas. Should a nozzle become clogged, it is best to blow out the dirt with compressed air or use a softbristled

brush such as a toothbrush. Wear waterproof gloves when handling and cleaning nozzles to reduce pesticide exposure. NEVER use a wire or nail as a cleaner because the orifice can be easily damaged. NEVER put tips in the mouth. Remember, improperly functioning or worn nozzles are

costly.

A spray nozzle is a precision device that facilitates dispersion of liquid into a spray. Nozzles are used for three purposes: to distribute a liquid over an area, to increase liquid surface area, and create impact force on a solid surface. A wide variety of spray nozzle applications use a number of spray characteristics to describe the spray.[1]

Spray nozzles can be categorized based on the energy input used to cause atomization, the breakup of the fluid into drops.[2][3] Spray nozzles can have one or more outlets; a multiple outlet nozzle is known as a compound nozzle.

Single-fluid nozzle[edit]

Single-fluid or hydraulic spray nozzles utilize the kinetic energy of the liquid to break it up into droplets. This most widely used type of spray nozzle is more energy efficient at producing surface area than most other types. As the fluid pressure increases, the flow through the nozzle increases, and the drop size decreases. Many configurations of single fluid nozzles are used depending on the spray characteristics desired.

Plain-orifice nozzle

The simplest single fluid nozzle is a plain orifice nozzle as shown in the diagram. This nozzle often produces little if any atomization, but directs the stream of liquid. If the pressure drop is high, at least 25 bars (2,500 kPa), the material is often finely atomized, as in a diesel injector. At lower pressures, this type of nozzle is often used for tank cleaning, either as a fixed position compound spray nozzle or as a rotary nozzle.

Shaped-orifice nozzle[edit]

The shaped orifice uses a hemispherical shaped inlet and a V notched outlet to cause the flow to spread out on the axis of the V notch. Aflat fan spray results which is useful for many spray applications, such as spray painting.

Surface-impingement single-fluid nozzle[edit]

  

Surface impingement spray nozzle

Spiral spray nozzle alt

A surface impingement nozzle causes a stream of liquid to impinge on a surface resulting in a sheet of liquid that breaks up into drops. This flat fan spray pattern nozzle is used in many applications ranging from applying agricultural herbicides to row crop to painting.

The impingement surface can be formed in a spiral to yield a spiral shaped sheet approximating a full cone spray pattern or a hollow-cone spray pattern.[4]

The spiral design generally produces a smaller drop size than pressure swirl type nozzle design, for a given pressure and flow rate. This design is clog resistant due to the large free passage.

Common applications include gas scrubbing applications (e.g., flue-gas desulfurization where the smaller droplets often offer superior performance) and fire fighting (where the mix of droplet densities allow spray penetration through strong thermal currents).

Pressure-swirl single-fluid spray nozzle[edit]

  

pressure swirl spray nozzle

  

Spillback Nozzle

Pressure-swirl spray nozzles are high-performance (small drop size) devices with one configuration shown. The stationary core induces a rotary fluid motion which causes the swirling of the fluid in the swirl chamber. A film is discharged from the perimeter of the outlet orifice producing a characteristic hollow cone spray pattern. Air or other surrounding gas is drawn inside the swirl chamber to form an air core within the swirling liquid. Many configurations of fluid inlets are used to produce this hollow cone pattern depending on the nozzle capacity and materials of construction. The uses of this nozzle include evaporative cooling and spray drying.

Solid-cone single-fluid nozzle[edit]

One of the configurations of the solid cone spray nozzle is shown in a schematic diagram. A swirling liquid motion is induced with the vane structure, however; the discharge flow fills the entire outlet orifice. For the same capacity and pressure drop, a full cone nozzle will produce a larger drop size than a hollow cone nozzle. The coverage is the desired feature for such a nozzle, which is often used for applications to distribute fluid over an area.

Compound nozzle[edit]

Compound pressure swirl spray nozzle with wide pattern

A compound nozzle is a type of nozzle in which several individual single or two fluid nozzles are incorporated into one nozzle body, as shown below. This allows design control of drop size and spray coverage angle.

Two-fluid nozzles[edit]

Two-fluid nozzles atomize by causing the interaction of high velocity gas and liquid. Compressed air is most often used as the atomizing gas, but sometimes steam or other gases are used. The many varied designs of two-fluid nozzles can be grouped into internal mix or external mix depending on the mixing point of the gas and liquid streams relative to the nozzle face.

•  

Internal mix two-fluid spray nozzle

•  

External mix two-fluid spray nozzle

•  

TwinFluid Nozzle

Internal-mix two-fluid nozzles[edit]

Internal mix nozzles contact fluids inside the nozzle; one configuration is shown in the figure above. Shearing between high velocity gas and low velocity liquid disintegrates the liquid stream into droplets, producing a high velocity spray. This type of nozzle tends to use less atomizing gas than an external mix atomizer and is better suited to higher viscosity streams. Many compound internal-mix nozzles are commercially used; e.g., for fuel oil atomization.

External-mix two-fluid nozzles[edit]

External mix nozzles contacts fluids outside the nozzle as shown in the schematic diagram. This type of spray nozzle may require more atomizing air and a higher atomizing air pressure drop because the mixing and atomization of liquid takes place outside the nozzle. The liquid pressure drop is lower for this type of nozzle, sometimes drawing liquid into the nozzle due to the suction caused by the atomizing air nozzles (siphon nozzle). If the liquid to be atomized contains solids an external mix atomizer may be preferred. This spray may be shaped to produce different spray patterns. A flat pattern is formed with additional air ports to flatten or reshape the circular spray cross-section discharge.

Control of two-fluid nozzles[edit]

Many applications use two-fluid nozzles to achieve a controlled small drop size over a range of operation. Each nozzle has a performance curve, and the liquid and gas flow rates determine the drop size.[5] Excessive drop size can lead to catastrophic equipment failure or may have an adverse effect on the process or product. For example, the gas conditioning tower in a cement plant often utilizes evaporative cooling caused by water atomized by two-fluid nozzles into the dust laden gas. If drops do not completely evaporate and strike a vessel wall dust will accumulate, resulting in the potential for flow restriction in the outlet duct, disrupting the plant operation.

Rotary atomizers

Rotary atomizers use a high speed rotating disk, cup or wheel to discharge liquid at high speed to the perimeter, forming a hollow cone spray. The rotational speed controls the drop size. Spray drying and spray painting are the most important and common uses of this technology.

Ultrasonic atomizers

Main article: Ultrasonic nozzle

How ultrasonic spray nozzles work.

This type of spray nozzle utilizes high frequency (20–180 kHz) vibration to produce narrow drop-size distribution and low velocity spray from a liquid. The vibration of a piezoelectric crystal causes capillary waves on the nozzle surface liquid film. An Ultrasonic nozzle can be key to high transfer efficiency and process stability as they are very hard to clog. They are particularly useful in medical device coatings for their reliability.

Electrostatic

Electrostatic charging of sprays is very useful for high transfer efficiency. Examples are the industrial spraying of coatings (paint) and applying lubricant oils. The charging is at high voltage (20–40 kV) but low current.

Nozzle performance factors

Liquid properties

Almost all drop size data supplied by nozzle manufacturers are based on spraying water under laboratory conditions, 70 °F (21 °C). The effect of liquid properties should be understood and accounted for when selecting a nozzle for a process that is drop size sensitive.

Temperature[edit]

Liquid temperature changes do not directly affect nozzle performance, but can affect viscosity, surface tension, and specific gravity, which can then influence spray nozzle performance.

Specific gravity[edit]

Specific gravity is the ratio of the mass of a given volume of liquid to the mass of the same volume of water. In spraying, the main effect of the specific gravity Sg of a liquid other than water is on the capacity of the spray nozzle. All vendor-supplied performance data for nozzles are based on spraying water. To determine the volumetric flowrate Q, of a liquid other than water the following equation should be used.

Viscosity[edit]

Dynamic viscosity is defined as the property of a liquid that resists change in the shape or arrangement of its elements during flow. Liquid viscosity primarily affects spray pattern formation and drop size. Liquids with a high viscosity require a higher minimum pressure to begin spray pattern formation and yield narrower spray angles compared to water.

Surface tension[edit]

The surface tension of a liquid tends to assume the smallest possible size, acting as a membrane under tension. Any portion of the liquid surface exerts a tension upon adjacent portions or upon other objects that it contacts. This force is in the plane of the surface, and its amount per unit of length is surface tension. The value for water is about 0.073 N/m at 21 °C. The main effects of surface tension are on minimum operating pressure, spray angle, and drop size. Surface tension is more apparent at low operating pressures. A higher surface tension reduces the spray angle, particularly on hollow cone nozzles. Low surface tensions can allow nozzles to be operated at lower pressures.

Nozzle wear[edit]

Nozzle wear is indicated by an increase in nozzle capacity and by a change in the spray pattern, in which the distribution (uniformity of spray pattern) deteriorates and increases drop size. Choice of a wear resistant material of construction increases nozzle life. Because many single fluid nozzles are used to meter flows, worn nozzles result in excessive liquid usage.

Material of construction[edit]

The material of construction is selected based on the fluid properties of the liquid that is to be sprayed and the environment surrounding the nozzle. Spray nozzles are most commonly fabricated from metals, such as brass, Stainless steel, and nickel alloys, but plastics such as PTFE and PVC and ceramics (alumina and silicon carbide) are also used. Several factors must be considered, including erosive wear, chemical attack, and the effects of high temperature.

Chapter 4

Pump

For other uses of “pump” or “pumps”, see Pump (disambiguation).

  

A small, electrically powered pump

  

A large, electrically driven pump (electropump) for waterworks near theHengsteysee, Germany

  

Horizontally mounted lobe pump (right) shown with its electric motor (left) and drive-shaft bearing (middle)

A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.[1]

Pumps operate by some mechanism (typically reciprocating or rotary), and consume energy to perform mechanical work by moving the fluid. Pumps operate via many energy sources, including manual operation, electricity, engines, or wind power, come in many sizes, from microscopic for use in medical applications to large industrial pumps.

Mechanical pumps serve in a wide range of applications such as pumping water from wells, aquarium filtering, pond filtering and aeration, in the car industry for water-cooling and fuel injection, in the energy industry for pumping oil and natural gas or for operating cooling towers. In the medical industry, pumps are used for biochemical processes in developing and manufacturing medicine, and as artificial replacements for body parts, in particular the artificial heart and penile prosthesis.

In biology, many different types of chemical and bio-mechanical pumps have evolved, and biomimicry is sometimes used in developing new types of mechanical pumps.

 

Contents

• Types
  • Positive displacement pump
    • Positive displacement pump behavior and safety
    • Positive displacement types
      • Rotary positive displacement pumps
      • Reciprocating positive displacement pumps
      • Various positive displacement pumps
        • Gear pump
        • Screw pump
        • Progressing cavity pump
        • Roots-type pumps
        • Peristaltic pump
        • Plunger pumps
        • Triplex-style plunger pumps
        • Compressed-air-powered double-diaphragm pumps
        • Rope pumps
  • Impulse pumps
    • Hydraulic ram pumps
  • Velocity pumps
    • Radial-flow pumps
    • Axial-flow pumps
    • Mixed-flow pumps
    • Eductor-jet pump
  • Gravity pumps
  • Steam pumps
  • Valveless pumps
• 2Pump repairs
• 3Applications
  • Priming a pump
  • Pumps as public water supplies
  • Sealing multiphase pumping applications
    • Types and features of multiphase pumps
• Specifications
• Pumping power
• Pump efficiency
• See also
• References
• Further reading
• External links

4.1 Types

Mechanical pumps may be submerged in the fluid they are pumping or be placed external to the fluid.

Pumps can be classified by their method of displacement into positive displacement pumps, impulse pumps, velocity pumps, gravity pumps, steam pumps and valveless pumps. There are two basic types of pumps: positive displacement and centrifugal. Although axial-flow pumps are frequently classified as a separate type, they have essentially the same operating principles as centrifugal pumps.[2]

Positive displacement pump[edit]

  

Lobe pump internals

A positive displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe.

Some positive displacement pumps use an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation.

Positive displacement pump behavior and safety[edit]

Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, theoretically can produce the same flow at a given speed (RPM) no matter what the discharge pressure. Thus, positive displacement pumps are constant flow machines. However, a slight increase in internal leakage as the pressure increases prevents a truly constant flow rate.

A positive displacement pump must not operate against a closed valve on the discharge side of the pump, because it has no shutoff head like centrifugal pumps. A positive displacement pump operating against a closed discharge valve continues to produce flow and the pressure in the discharge line increases until the line bursts, the pump is severely damaged, or both.

A relief or safety valve on the discharge side of the positive displacement pump is therefore necessary. The relief valve can be internal or external. The pump manufacturer normally has the option to supply internal relief or safety valves. The internal valve is usually only used as a safety precaution. An external relief valve in the discharge line, with a return line back to the suction line or supply tank provides increased safety.

Positive displacement types[edit]

A positive displacement pump can be further classified according to the mechanism used to move the fluid:

• Rotary-type positive displacement: internal gear, screw, shuttle block, flexible vane or sliding vane, circumferential piston, flexible impeller, helical twisted roots (e.g. the Wendelkolben pump) or liquid ring vacuum pumps
• Reciprocating-type positive displacement: piston or diaphragm pumps
• Linear-type positive displacement: rope pumps and chain pumps

Rotary positive displacement pumps[edit]

  

Rotary vane pump

These pumps move fluid using a rotating mechanism that creates a vacuum that captures and draws in the liquid[citation needed][dubious – discuss].

Advantages: Rotary pumps are very efficient[citation needed] because they naturally remove air from the lines, eliminating the need to bleed the air from the lines manually.

Drawbacks: The nature of the pump demands very close clearances between the rotating pump and the outer edge, making it rotate at a slow, steady speed. If rotary pumps are operated at high speeds, the fluids cause erosion, which eventually causes enlarged clearances that liquid can pass through, which reduces efficiency.

Rotary positive displacement pumps fall into three main types:

• Gear pumps – a simple type of rotary pump where the liquid is pushed between two gears
• Screw pumps – the shape of the internals of this pump is usually two screws turning against each other to pump the liquid
• Rotary vane pumps – similar to scroll compressors, these have a cylindrical rotor encased in a similarly shaped housing. As the rotor orbits, the vanes trap fluid between the rotor and the casing, drawing the fluid through the pump.

Reciprocating positive displacement pumps[edit]

  

Simple hand pump

  

Old hand water pump (c. 1924) at the Colored School in Alapaha, Georgia, US

 Reciprocating pump

Reciprocating pumps move the fluid using one or more oscillating pistons, plungers, or membranes (diaphragms), while valves restrict fluid motion to the desired direction.

Pumps in this category range from simplex, with one cylinder, to in some cases quad (four) cylinders, or more. Many reciprocating-type pumps are duplex (two) or triplex (three) cylinder. They can be either single-acting with suction during one direction of piston motion and discharge on the other, or double-acting with suction and discharge in both directions. The pumps can be powered manually, by air or steam, or by a belt driven by an engine. This type of pump was used extensively in the 19th century—in the early days of steam propulsion—as boiler feed water pumps. Now reciprocating pumps typically pump highly viscous fluids like concrete and heavy oils, and serve in special applications that demand low flow rates against high resistance. Reciprocating hand pumps were widely used to pump water from wells. Common bicycle pumps and foot pumps for inflation use reciprocating action.

These positive displacement pumps have an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pumps as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant given each cycle of operation.

Typical reciprocating pumps are:

• Plunger pumps – a reciprocating plunger pushes the fluid through one or two open valves, closed by suction on the way back.
• Diaphragm pumps – similar to plunger pumps, where the plunger pressurizes hydraulic oil which is used to flex a diaphragm in the pumping cylinder. Diaphragm valves are used to pump hazardous and toxic fluids.
• Piston pumps displacement pumps – usually simple devices for pumping small amounts of liquid or gel manually. The common hand soap dispenser is such a pump.
• Radial piston pumps

Various positive displacement pumps

The positive displacement principle applies in these pumps:

• Rotary lobe pump
• Progressive cavity pump
• Rotary gear pump
• Piston pump
• Diaphragm pump
• Screw pump
• Gear pump
• Hydraulic pump
• Rotary vane pump
• Peristaltic pump
• Rope pump
• Flexible impeller pump

Gear pump

  

Gear pump

This is the simplest of rotary positive displacement pumps. It consists of two meshed gears that rotate in a closely fitted casing. The tooth spaces trap fluid and force it around the outer periphery. The fluid does not travel back on the meshed part, because the teeth mesh closely in the center. Gear pumps see wide use in car engine oil pumps and in various hydraulic power packs.

Screw pump[edit]

  

Screw pump

Main article: Screw pump

A screw pump is a more complicated type of rotary pump that uses two or three screws with opposing thread — e.g., one screw turns clockwise and the other counterclockwise. The screws are mounted on parallel shafts that have gears that mesh so the shafts turn together and everything stays in place. The screws turn on the shafts and drive fluid through the pump. As with other forms of rotary pumps, the clearance between moving parts and the pump’s casing is minimal.

Progressing cavity pump

Widely used for pumping difficult materials, such as sewage sludge contaminated with large particles, this pump consists of a helical rotor, about ten times as long as its width. This can be visualized as a central core of diameter x with, typically, a curved spiral wound around of thickness halfx, though in reality it is manufactured in single casting. This shaft fits inside a heavy duty rubber sleeve, of wall thickness also typically x. As the shaft rotates, the rotor gradually forces fluid up the rubber sleeve. Such pumps can develop very high pressure at low volumes.

  

Roots-type pumps[edit]

  

A Roots lobe pump

Main article: Roots-type supercharger

Named after the Roots brothers who invented it, this lobe pump displaces the liquid trapped between two long helical rotors, each fitted into the other when perpendicular at 90°, rotating inside a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous flow with equal volume and no vortex. It can work at low pulsation rates, and offers gentle performance that some applications require.

Applications include:

• High capacity industrial air compressors
• Roots superchargers on internal combustion engines.
• A brand of civil defense siren, the Federal Signal Corporation‘s Thunderbolt.

Peristaltic pump

  

360° Peristaltic Pump

Main article: Peristaltic pump

A peristaltic pump is a type of positive displacement pump. It contains fluid within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A number of rollers, shoes, or wipers attached to a rotor compresses the flexible tube. As the rotor turns, the part of the tube under compression closes (or occludes), forcing the fluid through the tube. Additionally, when the tube opens to its natural state after the passing of the cam it draws (restitution) fluid into the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract.

 

Plunger pumps

Plunger pumps are reciprocating positive displacement pumps.

These consist of a cylinder with a reciprocating plunger. The suction and discharge valves are mounted in the head of the cylinder. In the suction stroke the plunger retracts and the suction valves open causing suction of fluid into the cylinder. In the forward stroke the plunger pushes the liquid out of the discharge valve. Efficiency and common problems: With only one cylinder in plunger pumps, the fluid flow varies between maximum flow when the plunger moves through the middle positions, and zero flow when the plunger is at the end positions. A lot of energy is wasted when the fluid is accelerated in the piping system. Vibration and water hammer may be a serious problem. In general the problems are compensated for by using two or more cylinders not working in phase with each other.

Triplex-style plunger pumps

Triplex plunger pumps use three plungers, which reduces the pulsation of single reciprocating plunger pumps. Adding a pulsation dampener on the pump outlet can further smooth the pump ripple, or ripple graph of a pump transducer. The dynamic relationship of the high-pressure fluid and plunger generally requires high-quality plunger seals. Plunger pumps with a larger number of plungers have the benefit of increased flow, or smoother flow without a pulsation dampener. The increase in moving parts and crankshaft load is one drawback.

Car washes often use these triplex-style plunger pumps (perhaps without pulsation dampeners). In 1968, William Bruggeman significantly reduced the size of the triplex pump and increased the lifespan so that car washes could use equipment with smaller footprints. Durable high pressure seals, low pressure seals and oil seals, hardened crankshafts, hardened connecting rods, thick ceramic plungers and heavier duty ball and roller bearings improve reliability in triplex pumps. Triplex pumps now are in a myriad of markets across the world.

Triplex pumps with shorter lifetimes are commonplace to the home user. A person who uses a home pressure washer for 10 hours a year may be satisfied with a pump that lasts 100 hours between rebuilds. Industrial-grade or continuous duty triplex pumps on the other end of the quality spectrum may run for as much as 2,080 hours a year.

The oil and gas drilling industry uses massive semi trailer-transported triplex pumps called mud pumps to pump drilling mud, which cools the drill bit and carries the cuttings back to the surface.[3] Drillers use triplex or even quintuplex pumps to inject water and solvents deep into shale in the extraction process called fracking.[4]

Compressed-air-powered double-diaphragm pump

One modern application of positive displacement diaphragm pumps is compressed-air-powered double-diaphragm pumps. Run on compresseair these pumps are intrinsically safe by design, although all manufacturers offer ATEX certified models to comply with industry regulation. These pumps are relatively inexpensive and can perform a wide variety of duties, from pumping water out of bunds, to pumping hydrochloric acid from secure storage (dependent on how the pump is manufactured – elastomers / body construction). Lift is normally limited to roughly 6m although heads can reach almost 200 psi (1.4 MPa).[citation needed]

Rope pumps

  

Rope pump schematic

Main article: Rope pump

Devised in China as chain pumps over 1000 years ago, these pumps can be made from very simple materials: A rope, a wheel and a PVC pipe are sufficient to make a simple rope pump. For this reason they have become extremely popular around the world since the 1980s. Rope pump efficiency has been studied by grass roots organizations and the techniques for making and running them have been continuously improved.[5]

Impulse pumps

Impulse pumps use pressure created by gas (usually air). In some impulse pumps the gas trapped in the liquid (usually water), is released and accumulated somewhere in the pump, creating a pressure that can push part of the liquid upwards.

Conventional impulse pumps include:

• Hydraulic ram pumps – kinetic energy of a low-head water supply is stored temporarily in an air-bubble hydraulic accumulator, then used to drive water to a higher head.
• Pulser pumps – run with natural resources, by kinetic energy only.
• Airlift pumps – run on air inserted into pipe, which pushes the water up when bubbles move upward

Instead of a gas accumulation and releasing cycle, the pressure can be created by burning of hydrocarbons. Such combustion driven pumps directly transmit the impulse form a combustion event through the actuation membrane to the pump fluid. In order to allow this direct transmission, the pump needs to be almost entirely made of an elastomer (e.g. silicone rubber). Hence, the combustion causes the membrane to expand and thereby pumps the fluid out of the adjacent pumping chamber. The first combustion-driven soft pump was developed by ETH Zurich.[6]

Hydraulic ram pumps

A hydraulic ram is a water pump powered by hydropower.

It takes in water at relatively low pressure and high flow-rate and outputs water at a higher hydraulic-head and lower flow-rate. The device uses the water hammer effect to develop pressure that lifts a portion of the input water that powers the pump to a point higher than where the water started.

The hydraulic ram is sometimes used in remote areas, where there is both a source of low-head hydropower, and a need for pumping water to a destination higher in elevation than the source. In this situation, the ram is often useful, since it requires no outside source of power other than the kinetic energy of flowing water.

Velocity pumps

  

A centrifugal pump uses an impellerwith backward-swept arms

Rotodynamic pumps (or dynamic pumps) are a type of velocity pump in which kinetic energy is added to the fluid by increasing the flow velocity. This increase in energy is converted to a gain in potential energy (pressure) when the velocity is reduced prior to or as the flow exits the pump into the discharge pipe. This conversion of kinetic energy to pressure is explained by the First law of thermodynamics, or more specifically by Bernoulli’s principle.

Dynamic pumps can be further subdivided according to the means in which the velocity gain is achieved.

These types of pumps have a number of characteristics:

1. Continuous energy
2. Conversion of added energy to increase in kinetic energy (increase in velocity)
3. Conversion of increased velocity (kinetic energy) to an increase in pressure head

A practical difference between dynamic and positive displacement pumps is how they operate under closed valve conditions. Positive displacement pumps physically displace fluid, so closing a valve downstream of a positive displacement pump produces a continual pressure build up that can cause mechanical failure of pipeline or pump. Dynamic pumps differ in that they can be safely operated under closed valve conditions (for short periods of time).

Radial-flow pumps

These are also referred to as centripetal design pumps. The fluid enters along the axis or center, is accelerated by the impeller and exits at right angles to the shaft(radially). Radial-flow pumps operate at higher pressures and lower flow rates than axial- and mixed-flow pumps.

Axial-flow pumps

These are also referred to as All fluid pumps The fluid is pushed outward or inward and move fluid axially. They operate at much lower pressures and higher flow rates than radial-flow (centripetal) pumps.

Mixed-flow pumps

Mixed-flow pumps function as a compromise between radial and axial-flow pumps. The fluid experiences both radial acceleration and lift and exits the impeller somewhere between 0 and 90 degrees from the axial direction. As a consequence mixed-flow pumps operate at higher pressures than axial-flow pumps while delivering higher discharges than radial-flow pumps. The exit angle of the flow dictates the pressure head-discharge characteristic in relation to radial and mixed-flow.

Eductor-jet pump

This uses a jet, often of steam, to create a low pressure. This low pressure sucks in fluid and propels it into a higher pressure region.

Gravity pumps

Gravity pumps include the syphon and Heron’s fountain. The hydraulic ram is also sometimes called a gravity pump; in a gravity pump the water is lifted by gravitational force.

Steam pumps

Steam pumps have been for a long time mainly of historical interest. They include any type of pump powered by a steam engine and also pistonless pumps such as Thomas Savery‘s or the Pulsometer steam pump.

Recently there has been a resurgence of interest in low power solar steam pumps for use in smallholder irrigation in developing countries. Previously small steam engines have not been viable because of escalating inefficiencies as vapour engines decrease in size. However the use of modern engineering materials coupled with alternative engine configurations has meant that these types of system are now a cost effective opportunity.

Valveless pumps

Valveless pumping assists in fluid transport in various biomedical and engineering systems. In a valveless pumping system, no valves (or physical occlusions) are present to regulate the flow direction. The fluid pumping efficiency of a valveless system, however, is not necessarily lower than that having valves. In fact, many fluid-dynamical systems in nature and engineering more or less rely upon valveless pumping to transport the working fluids therein. For instance, blood circulation in the cardiovascular system is maintained to some extent even when the heart’s valves fail. Meanwhile, the embryonic vertebrate heart begins pumping blood long before the development of discernible chambers and valves. In microfluidics, valveless impedance pumps have been fabricated, and are expected to be particularly suitable for handling sensitive biofluids. Ink jet printers operating on the Piezoelectric transducer principle also use valveless pumping. The pump chamber is emptied through the printing jet due to reduced flow impedance in that direction and refilled by capillary action..

Pump repairs

Examining pump repair records and mean time between failures (MTBF) is of great importance to responsible and conscientious pump users. In view of that fact, the preface to the 2006 Pump User’s Handbook alludes to “pump failure” statistics. For the sake of convenience, these failure statistics often are translated into MTBF (in this case, installed life before failure).[8]

In early 2005, Gordon Buck, John Crane Inc.’s chief engineer for Field Operations in Baton Rouge, LA, examined the repair records for a number of refinery and chemical plants to obtain meaningful reliability data for centrifugal pumps. A total of 15 operating plants having nearly 15,000 pumps were included in the survey. The smallest of these plants had about 100 pumps; several plants had over 2000. All facilities were located in the United States. In addition, considered as “new”, others as “renewed” and still others as “established”. Many of these plants—but not all—had an alliance arrangement with John Crane. In some cases, the alliance contract included having a John Crane Inc. technician or engineer on-site to coordinate various aspects of the program.

Not all plants are refineries, however, and different results occur elsewhere. In chemical plants, pumps have traditionally been “throw-away” items as chemical attack limits life. Things have improved in recent years, but the somewhat restricted space available in “old” DIN and ASME-standardized stuffing boxes places limits on the type of seal that fits. Unless the pump user upgrades the seal chamber, the pump only accommodates more compact and simple versions. Without this upgrading, lifetimes in chemical installations are generally around 50 to 60 percent of the refinery values.

Unscheduled maintenance is often one of the most significant costs of ownership, and failures of mechanical seals and bearings are among the major causes. Keep in mind the potential value of selecting pumps that cost more initially, but last much longer between repairs. The MTBF of a better pump may be one to four years longer than that of its non-upgraded counterpart. Consider that published average values of avoided pump failures range from US$2600 to US$12,000. This does not include lost opportunity costs. One pump fire occurs per 1000 failures. Having fewer pump failures means having fewer destructive pump fires.

As has been noted, a typical pump failure based on actual year 2002 reports, costs US$5,000 on average. This includes costs for material, parts, labor and overhead. Extending a pump’s MTBF from 12 to 18 months would save US$1,667 per year — which might be greater than the cost to upgrade the centrifugal pump’s reliability.

Applications

  

Metering pump for gasoline andadditives.

Pumps are used throughout society for a variety of purposes. Early applications includes the use of the windmill or watermill to pump water. Today, the pump is used for irrigation, water supply, gasoline supply, air conditioning systems, refrigeration (usually called a compressor), chemical movement, sewage movement, flood control, marine services, etc.

Because of the wide variety of applications, pumps have a plethora of shapes and sizes: from very large to very small, from handling gas to handling liquid, from high pressure to low pressure, and from high volume to low volume.

Priming a pump

Typically, a liquid pump can’t simply draw air. The feed line of the pump and the internal body surrounding the pumping mechanism must first be filled with the liquid that requires pumping: An operator must introduce liquid into the system to initiate the pumping. This is called priming the pump. Loss of prime is usually due to ingestion of air into the pump. The clearances and displacement ratios in pumps for liquids, whether thin or more viscous, usually cannot displace air due to its compressibility. This is the case with most velocity (rotodynamic) pumps — for example, centrifugal pumps.

Positive–displacement pumps, however, tend to have sufficiently tight sealing between the moving parts and the casing or housing of the pump that they can be described asself-priming. Such pumps can also serve as priming pumps, so called when they are used to fulfill that need for other pumps in lieu of action taken by a human operator.

One sort of pump once common worldwide was a hand-powered water pump, or ‘pitcher pump’. It was commonly installed over community water wells in the days before piped water supplies.

In parts of the British Isles, it was often called the parish pump. Though such community pumps are no longer common, people still used the expression parish pump to describe a place or forum where matters of local interest are discussed.[12]

Because water from pitcher pumps is drawn directly from the soil, it is more prone to contamination. If such water is not filtered and purified, consumption of it might lead to gastrointestinal or other water-borne diseases. A notorious case is the 1854 Broad Street cholera outbreak. At the time it was not known how cholera was transmitted, but physician John Snow suspected contaminated water and had the handle of the public pump he suspected removed; the outbreak then subsided.

Modern hand-operated community pumps are considered the most sustainable low-cost option for safe water supply in resource-poor settings, often in rural areas in developing countries. A hand pump opens access to deeper groundwater that is often not polluted and also improves the safety of a well by protecting the water source from contaminated buckets. Pumps such as the Afridev pump are designed to be cheap to build and install, and easy to maintain with simple parts. However, scarcity of spare parts for these type of pumps in some regions of Africa has diminished their utility for these areas.

Sealing multiphase pumping applications

Multiphase pumping applications, also referred to as tri-phase, have grown due to increased oil drilling activity. In addition, the economics of multiphase production is attractive to upstream operations as it leads to simpler, smaller in-field installations, reduced equipment costs and improved production rates. In essence, the multiphase pump can accommodate all fluid stream properties with one piece of equipment, which has a smaller footprint. Often, two smaller multiphase pumps are installed in series rather than having just one massive pump.

For midstream and upstream operations, multiphase pumps can be located o[13]nshore or offshore and can be connected to single or multiple wellheads. Basically, multiphase pumps are used to transport the untreated flow stream produced from oil wells to downstream processes or gathering facilities. This means that the pump may handle a flow stream (well stream) from 100 percent gas to 100 percent liquid and every imaginable combination in between. The flow stream can also contain abrasives such as sand and dirt. Multiphase pumps are designed to operate under changing/fluctuating process conditions. Multiphase pumping also helps eliminate emissions of greenhouse gases as operators strive to minimize the flaring of gas and the venting of tanks where possible.

Types and features of multiphase pumps

Helico-Axial Pumps (Centrifugal) A rotodynamic pump with one single shaft that requires two mechanical seals, this pump uses an open-type axial impeller. It’s often called aPoseidon pump, and can be described as a cross between an axial compressor and a centrifugal pump.

Twin Screw (Positive Displacement) The twin screw pump is constructed of two inter-meshing screws that move the pumped fluid. Twin screw pumps are often used when pumping conditions contain high gas volume fractions and fluctuating inlet conditions. Four mechanical seals are required to seal the two shafts.

Progressive Cavity Pumps (Positive Displacement) Progressive cavity pumps are single-screw types typically used in shallow wells or at the surface. This pump is mainly used on surface applications where the pumped fluid may contain a considerable amount of solids such as sand and dirt.

Electric Submersible Pumps (Centrifugal) These pumps are basically multistage centrifugal pumps and are widely used in oil well applications as a method for artificial lift. These pumps are usually specified when the pumped fluid is mainly liquid.

Buffer Tank A buffer tank is often installed upstream of the pump suction nozzle in case of a slug flow. The buffer tank breaks the energy of the liquid slug, smooths any fluctuations in the incoming flow and acts as a sand trap.

As the name indicates, multiphase pumps and their mechanical seals can encounter a large variation in service conditions such as changing process fluid composition, temperature variations, high and low operating pressures and exposure to abrasive/erosive media. The challenge is selecting the appropriate mechanical seal arrangement and support system to ensure maximized seal life and its overall effectiveness.

Specifications

Pumps are commonly rated by horsepower, flow rate, outlet pressure in metres (or feet) of head, inlet suction in suction feet (or metres) of head. The head can be simplified as the number of feet or metres the pump can raise or lower a column of water at atmospheric pressure.

From an initial design point of view, engineers often use a quantity termed the specific speed to identify the most suitable pump type for a particular combination of flow rate and head.

Pumping power

Bernoulli’s equation

The power imparted into a fluid increases the energy of the fluid per unit volume. Thus the power relationship is between the conversion of the mechanical energy of the pump mechanism and the fluid elements within the pump. In general, this is governed by a series of simultaneous differential equations, known as the Navier–Stokes equations. However a more simple equation relating only the different energies in the fluid, known as Bernoulli’s equation can be used. Hence the power, P, required by the pump:

where Δp is the change in total pressure between the inlet and outlet (in Pa), and Q, the volume flow-rate of the fluid is given in m3/s. The total pressure may have gravitational,static pressure and kinetic energy components; i.e. energy is distributed between change in the fluid’s gravitational potential energy (going up or down hill), change in velocity, or change in static pressure. η is the pump efficiency, and may be given by the manufacturer’s information, such as in the form of a pump curve, and is typically derived from either fluid dynamics simulation (i.e. solutions to the Navier–Stokes for the particular pump geometry), or by testing. The efficiency of the pump depends upon the pump’s configuration and operating conditions (such as rotational speed, fluid density and viscosity etc.)

For a typical “pumping” configuration, the work is imparted on the fluid, and is thus positive. For the fluid imparting the work on the pump (i.e. a turbine), the work is negative. Power required to drive the pump is determined by dividing the output power by the pump efficiency. Furthermore, this definition encompasses pumps with no moving parts, such as a siphon.

Pump efficiency

Pump efficiency is defined as the ratio of the power imparted on the fluid by the pump in relation to the power supplied to drive the pump. Its value is not fixed for a given pump, efficiency is a function of the discharge and therefore also operating head. For centrifugal pumps, the efficiency tends to increase with flow rate up to a point midway through the operating range (peak efficiency) and then declines as flow rates rise further. Pump performance data such as this is usually supplied by the manufacturer before pump selection. Pump efficiencies tend to decline over time due to wear (e.g. increasing clearances as impellers reduce in size).

When a system design includes a centrifugal pump, an important issue it its design is matching the head loss-flow characteristic with the pump so that it operates at or close to the point of its maximum efficiency.

Pump efficiency is an important aspect and pumps should be regularly tested. Thermodynamic pump testing is one method.

Bibliography:

www.google.com

www.wikipedia.com

http://www.aspee.com/

Project Report

On

SOLAR BASEB WATER SPRAYER

SUBMITTED BY:

SUBMITTED TO:

GURU NANAK DEV ENGINEERING COLLEGE

LUDHIANA

CANDIDATE DEACLARATION

I hereby affirm that I undertaken the project report on the water sprayer during the period in the partial fulfillment of requirement of the award of B.Tech. (Electrical Engineering) at PUNJAB TECHNICAL UNIVERSITY, JALANDHAR.

The work which is being presented report submitted to the Department of Electrical Engineering at Bhutta College of Engineering & Technology, Ludhiana is an authentic record of the project work.

The project report examination of________________________has been held on

______________and accepted.

Signature of internal Examiner                            Signature of External Examiner

ACKNOWLEDGEMENT

Many individual have proudly influenced us during our undergraduate studies (B.Tech.) at BCET, LUDHIANA and it is pleasure to acknowledge their guidance and support In college, I learned many things, like, the project training is mainly aimed at enabling the student to apply their theoretical knowledge to practical as “The theory is to know how and practical to do how” and to appreciate the limitation of knowledge gained in the class room to practical situation and to appreciate the importance of discipline, punctuality, team work, sense of responsibility, money, value of time, dignity of labour.

I will like to express my gratitude towards Er. Chamandeep Kaurwho took keen interest in our project,Who helped me in every possible way and is source of inspiration for all the group members.

I would also like to thank to all Electrical Department of BCET Ludhiana who motivated me to complete our project with enthusiasm and hard work. He helped every time when I need

GURPREET SINGH

JATINDER PAL SINGH

AMRINDER SINGH

Objective:

The main objective of this project is to make a spray pump which can be operated on both AC and DC supply voltages.When AC source is present we operate it on AC voltage.When AC is OFF then we will take advantage of DC supply.we will just connect a DC battery of 12 volt to DC pump.DC pump will get on and spray pump will start working.

Specifications

Battery 12 volt, 2.5A

DC Pump 12 Volt,3A

Sprat Tank 20 lts

Spray tank nozzle

Connecting wires

Tabole of Content

Title                                                                                                Page No.

Specifications                                                                                                       5

Itroduction                                                                                                   6

Diagram                                                                                                              7

Chapter 1

Sprinkler                                                                                                           8

chapter 2

Nozzle                                                                                                                10

Chapter 3

Sprayer Nozzle

chapter 4    

Pump                                                                                                            

Bibliography                                                                                                       56

Introduction:

In this project we will make a spray pump operated with AC and DC supply Both.Project is tough  for us because it contain some electrical parts and mechanical parts.We used 12v DC pump for water spray.DC Pump is connected to DC supply source.for this purpose we use a DC battery.which is of 12 volts and 2.5 A.when Dc pump is connected to positive and negative terminal of battery,then pump will get on.It will start spray through nozzle.we have connected a switch between Pump and battery to on and off the spray pump.in this project we have connected a AC pump also.which is operated on AC supply of 220 volts.AC pump is of 220c AC and 1A.we will connect AC pump to AC supply through Power lead.pump will get on.It will start spray the liquid through nozzle.In This way we can spray using Both AC and Supply Through AC and DC Pumps.

Diagram

Chapter 1

Sprinklers

Sprinklers that spray in a fixed pattern are generally called sprays or spray heads. Sprays are not usually designed to operate at pressures above 30 lbf/in² (200 kPa) (30psi “Pounds per square inch”), due to misting problems that may develop.

Higher pressure sprinklers that themselves move in a circle are driven by a ball drive, gear drive, or impact mechanism (impact sprinklers). These can be designed to rotate in a full or partial circle.

Rainguns are similar to impact sprinkler, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). In addition to irrigation, guns are used for industrial applications such as dust suppression and logging.

Many irrigation sprinklers are buried in the ground along with their supporting plumbing, although above ground and moving sprinklers are also common. Most irrigation sprinklers operate through electric and hydraulic technology and are grouped together in zones that can be collectively turned on and off by actuating a solenoid-controlled valve.

An impact sprinkler head in action

Residential sprinklers  This section requires expansion.

Home lawn sprinklers vary widely in their size, cost, and complexity. They include impact sprinklers, oscillating sprinklers, drip sprinklers, and underground sprinkler systems. Small sprinklers are available at home and garden stores or hardware stores for small costs. These are often attached to an outdoor water faucet and are placed only temporarily. Other systems may be professionally installed permanently in the ground and are attached permanently to a home’s plumbing system.

Permanently installed system may often operate on timers or other automated processes. They are occasionally installed with retractable heads for aesthetic and practical reasons (making damage during lawn mowing or other maintenance less likely). These often are programed to operate at certain times of day or on some other schedule.

1.1 Underground sprinklers

Underground sprinklers function through means of basic electronic and hydrolic technology. This valve and all of the sprinklers that will be activated by this valve are known as a zone. Upon activation, the solenoid, which sits on top of the valve is magnetized lifting a small stainless steel plunger in its center. By doing this, the activated (or raised) plunger allows air to escape from the top of a rubber diaphragm located in the center of the valve. Water that has been charged and waiting on the bottom of this same diaphragm now has the higher pressure and lifts the diaphragm. This pressurized water is then allowed to escape down stream of the valve through a series of pipes, usually made of PVC. At the end of these pipes and flush to ground level (typically) are pre measured and spaced out sprinklers. These sprinklers can be fixed spray heads that have a set pattern and generally spray between 1.5-2m (7–15 ft.), full rotating sprinklers that can spray a broken stream of water from 6-12m (20–40 ft.), or small drip emitters that release a slow, steady drip of water on more delicate plants such as flowers and shrubs.

1.2 Sprinkler use

Most irrigation sprinklers are used as part of a sprinkler system, consisting of various plumbing parts, piping and control equipment. Piping is connected to the water source via plumbing fittings and the control system opens and closes valves to provide water on a schedule. The control provided varies depending on the equipment used; some systems are fully automated and even compensate for rain, runoff and evaporation, while others require much more user attention for the same effectiveness.

Outdoor sprinkler systems are sometimes used as a deterrent against homeless people. For example, the city of Los Angeles installed an elaborate overhead sprinkler system in a downtown park along lower Fifth Street. This sprinkler system was programmed to drench unsuspecting sleepers at random times during the night. Local businessmen soon copied this system in an effort to drive homeless people away from public sidewalks adjacent to their businesses.

Chapter 2

Nozzle

A nozzle is a device designed to control the direction or characteristics of a fluid flow (especially to increase velocity) as it exits (or enters) an enclosed chamber or pipe.

A nozzle is often a pipe or tube of varying cross sectional area, and it can be used to direct or modify the flow of a fluid (liquid or gas). Nozzles are frequently used to control the rate of flow, speed, direction, mass, shape, and/or the pressure of the stream that emerges from them. In nozzle velocity of fluid increases on the expense of its pressure energy.

2.1 Jet

A gas jet, fluid jet, or hydro jet is a nozzle intended to eject gas or fluid in a coherent stream into a surrounding medium. Gas jets are commonly found in gas stoves, ovens, or barbecues. Gas jets were commonly used for light before the development of electric light. Other types of fluid jets are found in carburetors, where smooth calibrated orifices are used to regulate the flow of fuel into an engine, and in jacuzzis or spas.

Another specialized jet is the laminar jet. This is a water jet that contains devices to smooth out the pressure and flow, and gives laminar flow, as its name suggests. This gives better results for fountains.

The foam jet is another type of jet which uses foam instead of a gas or fluid.

Nozzles used for feeding hot blast into a blast furnace or forge are called tuyeres.

Jet nozzles are also use in large rooms where the distribution of air via ceiling diffusers is not possible or not practical. Diffusers that uses jet nozzles are called jet diffuser where it will be arranged in the side wall areas in order to distribute air. When the temperature difference between the supply air and the room air changes, the supply air stream is deflected upwards, to supply warm air, or downwards, to supply cold air.

2.2 High velocity

  

A rocket nozzle

 a convergent nozzle to expand supersonically externally. The shape of the divergent section also ensures that the direction of the escaping gases is directly backwards, as any sideways component would not contribute to thrust.

2.3 Propelling

 

Frequently, the goal of a nozzle is to increase the kinetic energy of the flowing medium at the expense of its pressure and internal energy.

• Nozzles can be described as convergent (narrowing down from a wide diameter to a smaller diameter in the direction of the flow) ordivergent (expanding from a smaller diameter to a larger one). A de Laval nozzle has a convergent section followed by a divergent section and is often called a convergent-divergent nozzle (“con-di nozzle”).
• Convergent nozzles accelerate subsonic fluids. If the nozzle pressure ratio is high enough, then the flow will reach sonic velocity at the narrowest point (i.e. the nozzle throat). In this situation, the nozzle is said to be choked.
• Increasing the nozzle pressure ratio further will not increase the throat Mach number above one. Downstream (i.e. external to the nozzle) the flow is free to expand to supersonic velocities; however Mach 1 can be a very high speed for a hot gas because the speed of soundvaries as the square root of absolute temperature. This fact is used extensively in rocketry where hypersonic flows are required and where propellant mixtures are deliberately chosen to further increase the sonic speed.
• Divergent nozzles slow fluids if the flow is subsonic, but they accelerate sonic or supersonic fluids.
• Convergent-divergent nozzles can therefore accelerate fluids that have choked in the convergent section to supersonic speeds. This CD process is more efficient than allowing

Propelling nozzle

A jet exhaust produces a net thrust from the energy obtained from combusting fuel which is added to the inducted air. This hot air passes through a high speed nozzle, apropelling nozzle, which enormously increases its kinetic energy.[2]

Increasing exhaust velocity increases thrust for a given mass flow, but matching the exhaust velocity to the air speed provides the best energy efficiency. However, momentum considerations prevent jet aircraft from maintaining velocity while exceeding their exhaust jet speed. The engines of supersonic jet aircraft, such as those of fighters and SSTaircraft (e.g. Concorde) almost always achieve the high exhaust speeds necessary for supersonic flight by using a CD nozzle despite weight and cost penalties; conversely, subsonic jet engines employ relatively low, subsonic, exhaust velocities and therefore employ simple convergent nozzle, or even bypass nozzles at even lower speeds.

Rocket motors maximise thrust and exhaust velocity by using convergent-divergent nozzles with very large area ratios and therefore extremely high pressure ratios. Mass flow is at a premium because all the propulsive mass is carried with vehicle, and very high exhaust speeds are desirable.

2.4 Magnetic

Magnetic nozzles have also been proposed for some types of propulsion, such as VASIMR, in which the flow of plasma is directed by magnetic fields instead of walls made of solid matter.

2.5 Spray

Many nozzles produce a very fine spray of liquids.

• Atomizer nozzles are used for spray painting, perfumes, carburetors for internal combustion engines, spray on deodorants, antiperspirants and many other similar uses.
• Air-Aspirating Nozzle uses an opening in the cone shaped nozzle to inject air into a stream of water based foam (CAFS/AFFF/FFFP) to make the concentrate “foam up”. Most commonly found on foam extinguishers and foam handlines.
• Swirl nozzles inject the liquid in tangentially, and it spirals into the center and then exits through the central hole. Due to the vortexing this causes the spray to come out in a cone shape.

2.6 Vacuum

Vacuum cleaner nozzles come in several different shapes. Vacuum Nozzles are used in vacuum cleaners.

2.7 Shaping

Some nozzles are shaped to produce a stream that is of a particular shape. For example, extrusion molding is a way of producing lengths of metals or plastics or other materials with a particular cross-section. This nozzle is typically referred to as a die.

Chapter 3

 Sprayer Nozzles

The proper selection of a nozzle type and size is essential for proper pesticide application. This publication covers nozzle description, recommended uses, selection of the proper nozzle type, and the .ounce. calibration method. A listing of nozzle manufacturers also is included.The proper selection of a nozzle type and size is essential for proper pesticide application. The nozzle is a major factor in determining the amount of spray applied to an area, the uniformity of application, the coverage obtained on the target surface, and the amount of potential drift.Nozzles break the liquid into droplets, form the spray pattern, and propel the droplets in the proper direction. Nozzles determine the amount of spray volume at a given operating pressure, travel speed, and spacing. Drift can be minimized by selecting nozzles that produce the largest droplet size while providing adequate coverage at the intended application rate and pressure.Minimizing drift is especially important for herbicides.

Nozzle Description

Nozzle types commonly used in low-pressure agricultural sprayers include flat-fan, flood, raindrop, hollow-cone, fullcone,and others. Special features, or subtypes such as .extended range,. are available for some nozzle types.

Flat-fan

Flat-fan nozzles are widely used for broadcast spraying of herbicides. These nozzles produce a tapered-edge, flatfan spray pattern . These nozzles have several subtypes, such as standard flat-fan, even flat-fan, low pressure flat-fan, extended-range flat-fan, and some special types such as off-center flat-fans and twin-orifice flat-fans.The standard flat-fan normally operates between 30  and 60 pounds per square inch (psi), with an ideal range between 30 and 40 psi. The even flat-fan nozzles  apply uniform coverage across the entire width of the spray pattern. They are used for banding pesticide over the row and should not be used for broadcast applications. The band width can be controlled with the nozzle height and the spray angle. The low pressure flat-fan develops a normal flat-fan angle and spray pattern at operating pressures between 15 and 20 psi. Lower pressures result in larger droplets and less drift, but a low-pressure nozzle produces a smaller droplet at the same pressure as a standard nozzle.

The extended range flat-fan provides excellent drift control when operated between 15 and 25 ps uniform distribution of a flat-fan nozzle and wants lower operating pressures for drift control. Since extended range nozzles have an excellent spray distribution over a wide range of pressures (15-60 psi), they are ideal for sprayers equipped with flow controllers. The special feature flat-fan nozzle, such as the offcenter flat-fan, is used for boom end nozzles so a wide swath projection is obtained. The twin-orifice flat-fan produces two spray patterns . one angled 30 degrees forward, and the other directed 30 degrees backward.The droplets are small due to the atomizing by two smaller orifices. The two spray directions and smaller droplets improve coverage and penetration, a plus when applying postemergence contact herbicides. To produce fine droplets, the twin-orifice usually operates between 30 and 60 psi. Flat-fan nozzles are available in several spray angles. The most common spray angles are 65, 73, 80, and 110 degrees. Recommended nozzle heights for flat-fan nozzles during broadcast application are given in Table I. Figures 1A and 1B illustrate two spray overlap percentages. Figure 1C illustrates proper spray pattern. The spray pattern will be uneven if nozzles are not aligned properly on the spray boom. Rotate nozzles about ten degrees from the axis of the boom to prevent droplets from adjacent nozzles from touching but still allow for proper overlap of the spray pattern. The correct nozzle height is measured from the nozzle to the target, which may be the top of the ground, growing canopy, or stubble. Use 110-degree nozzles when booms are at lower heights and 80-degree nozzles when booms are higher. Although wide-angle nozzles produce smaller droplets that are more prone to drift, the reduction of boom height reduces the drift potential more than droplet size. The nozzle spacing and orientation should provide for 100 percent overlap and target height. Nozzles should not be oriented more than 30 degrees from vertical. The following are examples of nozzle numbering systems by two manufacturers. Spraying Systems Company* identifies its flat-fan nozzles with a four or five digit number. The first numbers are the spray angle, and the other numbers signify the discharge rate at rated pressure. For example, an 8005 has an 80-degree spray angle and will apply 0.5 gallons per minute (GPM) at rated pressure of 40 psi. An 11002 nozzle has a 110-degree spray angle and will apply 0.2 GPM at rated pressure of 40 psi. Additional designations are .SS. (stainless steel), .HSS. (hardened stainless steel), and .VS. (color-coded stainless steel). Delevan* flat-fan nozzles are identified by .LF. or .LF-R,. which reflect the standard and extended range flat-fan nozzles. The first numbers are the spray angle followed by a dash and then the discharge rate at rated pressure. For example, an LF80-5R is an extended range nozzle with an 80-degree spray angle and will apply 0.5 GPM at the rated pressure of 40 psi.

3.1 Flood

Flood nozzles  are popular for applying suspension fertilizers where clogging is a potential problem.These nozzles produce large droplets at pressures of 10 to 25 psi. The nozzles should be spaced less than 60 inches. The nozzle orientation should be set for 100 percent overlap. These nozzles are generally not suited for contact herbicide applications. Nozzle spacing between 30 and 40 inches produces the best spray patterns. Pressure influences spray patterns of flooding nozzles more than flat-fan nozzles. However, the spray pattern is not as uniform as with the flat-fan nozzles, and special attention to nozzle orientation and correct overlap is critical. Other than fertilizer suspensions, these nozzles are most often used with soil-incorporated herbicides with spray kits mounted on tillage implements. Flooding nozzles are designated .TK. by Spraying Systems and .D. by Delavan. The value following the letters is the flow rate times 10 at rated pressure of 10 psi. For example, TK-SS2 or D-2 are flood nozzles that apply 0.2 GPM at 10 psi.

3.2 Raindrop

Raindrop nozzles produce large drops in a hollow-cone pattern at pressures from 20 to 50 psi. The .RA. Raindrop nozzles are used for herbicide incorporation and are usually mounted on tillage implements. When used for broadcast application, nozzles should be oriented 30 degrees from the horizontal. The spray patterns should be overlapped 100 percent to obtain uniform distribution. These nozzles are not satisfactory for postemergence or non-incorporated herbicides because the droplet size is too large.

3.3 Hollow-cone

Hollow-cone nozzles  generally are used to apply insecticides or fungicides to field crops when foliage penetration and complete coverage of the leaf surface is required. These nozzles operate in a pressure range from 40 to 100 psi. Spray drift potential is higher from hollow-cone nozzles than from other nozzles due to the small droplets produced. Generally, this type of nozzle should not be used to apply herbicides.

3.4 Full-cone

The wide-angle, full-cone nozzles are a good choice if drift is a concern because they produce larger droplets than flood nozzles. Full-cone nozzles usually are recommended over flood nozzles for soil-incorporated herbicides. Full-cone nozzles operate between a pressure range of 15

to 40 psi and are ideal for sprayers equipped with flow controllers.

3.5 Fine Hollow-cone

The Cone-Jet (Spray Systems) and WRW-Whirl Rain (Delavan) are wide-angle (80-120 degrees), hollow-cone nozzles. These nozzles are used for postemergence contact  herbicides where a finely atomized spray is used for complete coverage of plants or weeds.

3.6 Nozzle Materials

Nozzles can be made from several materials. The most common are brass, nylon, stainless steel, hardened stainless steel, tungsten carbide, and ceramic. Ceramic and tungsten carbide nozzles are very long-wearing and extremely corrosion- resistant. Stainless steel nozzles last longer than brass or nylon and generally produce a more uniform pattern over an extended time period. Nylon nozzles with stainless steel or hardened stainless steel inserts offer an alternative to solid stainless steel nozzles at a reduced cost. Thermoplastic nozzles have good abrasion resistance, but swelling can occur with some chemicals, and they are easily damaged when cleaned. Nozzles made from hard materials cost more initially, but in the long run, they pay for themselves because of long-lasting properties. Do not mix nozzles of different materials, types, spray angles, or spray volumes on the same spray boom. A mixture of nozzles produces uneven spray distribution.

3.7 Nozzle Screens

To prevent plugging and excessive wear of the nozzles,always use screens  to remove large particles from the spray mixture, except when spraying very large volumes. At low rates, use 100-mesh screens. When using higher rates or applying wettable powders, use the 50-mesh size; check the manufacturer.s recommendations for the specific nozzle. Smaller mesh screens may plug more easily and therefore require more frequent cleaning. Some screenshave a ball check valve to prevent drip when the sprayer boom is turned off . These are useful if you stop in the field since excessive residues may damage the succeeding crop. Another available anti-drip device is a diaphragm check valve (Figure 5). This valve allows the nozzle tip to be changed without letting spray material leak from the boom.Also, the diaphragm helps to protect the device from chemical corrosion which could cause a check valve to fail.

Sprayer Calibration with the .Ounce.

Method

1. Use the chart below for distance to drive in the field.Use nozzle spacing for booms. For directed and band rigs,use the row spacing.

2. Set throttle for spraying and operate all equipment.Note seconds required to drive measured distance.

3. Catch spray for the noted time in Step 2 in container marked in ounces (a calibrated bottle or measuring cup).If boom, catch spray from one nozzle during noted time.On directed rigs, catch spray from all nozzles per row for

noted time.

4. Nozzle or nozzle group output in ounces equals gallons per acre actually applied.

5. Repeat for each nozzle to assure uniform distribution.

Row Width Row Width

or Nozzle Distance or Nozzle Distance

Spacing (IN) (FT) Spacing (IN) (FT)

40 102 26 157

38 107 24 170

36 113 22 185

34 120 20 204

32 127 18 227

30 136 16 255

28 146 14 291

Replacing Nozzle Tips

Worn nozzles increase application rates and change distribution patterns. The result is poor pest control, crop damage, residue problems, and increased costs. A check of the boom sprayer assures that each tip is delivering an identical volume of spray in a smooth pattern with no heavy streams or blank areas. Should a nozzle become clogged, it is best to blow out the dirt with compressed air or use a softbristled

brush such as a toothbrush. Wear waterproof gloves when handling and cleaning nozzles to reduce pesticide exposure. NEVER use a wire or nail as a cleaner because the orifice can be easily damaged. NEVER put tips in the mouth. Remember, improperly functioning or worn nozzles are

costly.

A spray nozzle is a precision device that facilitates dispersion of liquid into a spray. Nozzles are used for three purposes: to distribute a liquid over an area, to increase liquid surface area, and create impact force on a solid surface. A wide variety of spray nozzle applications use a number of spray characteristics to describe the spray.[1]

Spray nozzles can be categorized based on the energy input used to cause atomization, the breakup of the fluid into drops.[2][3] Spray nozzles can have one or more outlets; a multiple outlet nozzle is known as a compound nozzle.

Single-fluid nozzle[edit]

Single-fluid or hydraulic spray nozzles utilize the kinetic energy of the liquid to break it up into droplets. This most widely used type of spray nozzle is more energy efficient at producing surface area than most other types. As the fluid pressure increases, the flow through the nozzle increases, and the drop size decreases. Many configurations of single fluid nozzles are used depending on the spray characteristics desired.

Plain-orifice nozzle

The simplest single fluid nozzle is a plain orifice nozzle as shown in the diagram. This nozzle often produces little if any atomization, but directs the stream of liquid. If the pressure drop is high, at least 25 bars (2,500 kPa), the material is often finely atomized, as in a diesel injector. At lower pressures, this type of nozzle is often used for tank cleaning, either as a fixed position compound spray nozzle or as a rotary nozzle.

Shaped-orifice nozzle[edit]

The shaped orifice uses a hemispherical shaped inlet and a V notched outlet to cause the flow to spread out on the axis of the V notch. Aflat fan spray results which is useful for many spray applications, such as spray painting.

Surface-impingement single-fluid nozzle[edit]

  

Surface impingement spray nozzle

Spiral spray nozzle alt

A surface impingement nozzle causes a stream of liquid to impinge on a surface resulting in a sheet of liquid that breaks up into drops. This flat fan spray pattern nozzle is used in many applications ranging from applying agricultural herbicides to row crop to painting.

The impingement surface can be formed in a spiral to yield a spiral shaped sheet approximating a full cone spray pattern or a hollow-cone spray pattern.[4]

The spiral design generally produces a smaller drop size than pressure swirl type nozzle design, for a given pressure and flow rate. This design is clog resistant due to the large free passage.

Common applications include gas scrubbing applications (e.g., flue-gas desulfurization where the smaller droplets often offer superior performance) and fire fighting (where the mix of droplet densities allow spray penetration through strong thermal currents).

Pressure-swirl single-fluid spray nozzle[edit]

  

pressure swirl spray nozzle

  

Spillback Nozzle

Pressure-swirl spray nozzles are high-performance (small drop size) devices with one configuration shown. The stationary core induces a rotary fluid motion which causes the swirling of the fluid in the swirl chamber. A film is discharged from the perimeter of the outlet orifice producing a characteristic hollow cone spray pattern. Air or other surrounding gas is drawn inside the swirl chamber to form an air core within the swirling liquid. Many configurations of fluid inlets are used to produce this hollow cone pattern depending on the nozzle capacity and materials of construction. The uses of this nozzle include evaporative cooling and spray drying.

Solid-cone single-fluid nozzle[edit]

One of the configurations of the solid cone spray nozzle is shown in a schematic diagram. A swirling liquid motion is induced with the vane structure, however; the discharge flow fills the entire outlet orifice. For the same capacity and pressure drop, a full cone nozzle will produce a larger drop size than a hollow cone nozzle. The coverage is the desired feature for such a nozzle, which is often used for applications to distribute fluid over an area.

Compound nozzle[edit]

Compound pressure swirl spray nozzle with wide pattern

A compound nozzle is a type of nozzle in which several individual single or two fluid nozzles are incorporated into one nozzle body, as shown below. This allows design control of drop size and spray coverage angle.

Two-fluid nozzles[edit]

Two-fluid nozzles atomize by causing the interaction of high velocity gas and liquid. Compressed air is most often used as the atomizing gas, but sometimes steam or other gases are used. The many varied designs of two-fluid nozzles can be grouped into internal mix or external mix depending on the mixing point of the gas and liquid streams relative to the nozzle face.

•  

Internal mix two-fluid spray nozzle

•  

External mix two-fluid spray nozzle

•  

TwinFluid Nozzle

Internal-mix two-fluid nozzles[edit]

Internal mix nozzles contact fluids inside the nozzle; one configuration is shown in the figure above. Shearing between high velocity gas and low velocity liquid disintegrates the liquid stream into droplets, producing a high velocity spray. This type of nozzle tends to use less atomizing gas than an external mix atomizer and is better suited to higher viscosity streams. Many compound internal-mix nozzles are commercially used; e.g., for fuel oil atomization.

External-mix two-fluid nozzles[edit]

External mix nozzles contacts fluids outside the nozzle as shown in the schematic diagram. This type of spray nozzle may require more atomizing air and a higher atomizing air pressure drop because the mixing and atomization of liquid takes place outside the nozzle. The liquid pressure drop is lower for this type of nozzle, sometimes drawing liquid into the nozzle due to the suction caused by the atomizing air nozzles (siphon nozzle). If the liquid to be atomized contains solids an external mix atomizer may be preferred. This spray may be shaped to produce different spray patterns. A flat pattern is formed with additional air ports to flatten or reshape the circular spray cross-section discharge.

Control of two-fluid nozzles[edit]

Many applications use two-fluid nozzles to achieve a controlled small drop size over a range of operation. Each nozzle has a performance curve, and the liquid and gas flow rates determine the drop size.[5] Excessive drop size can lead to catastrophic equipment failure or may have an adverse effect on the process or product. For example, the gas conditioning tower in a cement plant often utilizes evaporative cooling caused by water atomized by two-fluid nozzles into the dust laden gas. If drops do not completely evaporate and strike a vessel wall dust will accumulate, resulting in the potential for flow restriction in the outlet duct, disrupting the plant operation.

Rotary atomizers

Rotary atomizers use a high speed rotating disk, cup or wheel to discharge liquid at high speed to the perimeter, forming a hollow cone spray. The rotational speed controls the drop size. Spray drying and spray painting are the most important and common uses of this technology.

Ultrasonic atomizers

Main article: Ultrasonic nozzle

How ultrasonic spray nozzles work.

This type of spray nozzle utilizes high frequency (20–180 kHz) vibration to produce narrow drop-size distribution and low velocity spray from a liquid. The vibration of a piezoelectric crystal causes capillary waves on the nozzle surface liquid film. An Ultrasonic nozzle can be key to high transfer efficiency and process stability as they are very hard to clog. They are particularly useful in medical device coatings for their reliability.

Electrostatic

Electrostatic charging of sprays is very useful for high transfer efficiency. Examples are the industrial spraying of coatings (paint) and applying lubricant oils. The charging is at high voltage (20–40 kV) but low current.

Nozzle performance factors

Liquid properties

Almost all drop size data supplied by nozzle manufacturers are based on spraying water under laboratory conditions, 70 °F (21 °C). The effect of liquid properties should be understood and accounted for when selecting a nozzle for a process that is drop size sensitive.

Temperature[edit]

Liquid temperature changes do not directly affect nozzle performance, but can affect viscosity, surface tension, and specific gravity, which can then influence spray nozzle performance.

Specific gravity[edit]

Specific gravity is the ratio of the mass of a given volume of liquid to the mass of the same volume of water. In spraying, the main effect of the specific gravity Sg of a liquid other than water is on the capacity of the spray nozzle. All vendor-supplied performance data for nozzles are based on spraying water. To determine the volumetric flowrate Q, of a liquid other than water the following equation should be used.

Viscosity[edit]

Dynamic viscosity is defined as the property of a liquid that resists change in the shape or arrangement of its elements during flow. Liquid viscosity primarily affects spray pattern formation and drop size. Liquids with a high viscosity require a higher minimum pressure to begin spray pattern formation and yield narrower spray angles compared to water.

Surface tension[edit]

The surface tension of a liquid tends to assume the smallest possible size, acting as a membrane under tension. Any portion of the liquid surface exerts a tension upon adjacent portions or upon other objects that it contacts. This force is in the plane of the surface, and its amount per unit of length is surface tension. The value for water is about 0.073 N/m at 21 °C. The main effects of surface tension are on minimum operating pressure, spray angle, and drop size. Surface tension is more apparent at low operating pressures. A higher surface tension reduces the spray angle, particularly on hollow cone nozzles. Low surface tensions can allow nozzles to be operated at lower pressures.

Nozzle wear[edit]

Nozzle wear is indicated by an increase in nozzle capacity and by a change in the spray pattern, in which the distribution (uniformity of spray pattern) deteriorates and increases drop size. Choice of a wear resistant material of construction increases nozzle life. Because many single fluid nozzles are used to meter flows, worn nozzles result in excessive liquid usage.

Material of construction[edit]

The material of construction is selected based on the fluid properties of the liquid that is to be sprayed and the environment surrounding the nozzle. Spray nozzles are most commonly fabricated from metals, such as brass, Stainless steel, and nickel alloys, but plastics such as PTFE and PVC and ceramics (alumina and silicon carbide) are also used. Several factors must be considered, including erosive wear, chemical attack, and the effects of high temperature.

Chapter 4

Pump

For other uses of “pump” or “pumps”, see Pump (disambiguation).

  

A small, electrically powered pump

  

A large, electrically driven pump (electropump) for waterworks near theHengsteysee, Germany

  

Horizontally mounted lobe pump (right) shown with its electric motor (left) and drive-shaft bearing (middle)

A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.[1]

Pumps operate by some mechanism (typically reciprocating or rotary), and consume energy to perform mechanical work by moving the fluid. Pumps operate via many energy sources, including manual operation, electricity, engines, or wind power, come in many sizes, from microscopic for use in medical applications to large industrial pumps.

Mechanical pumps serve in a wide range of applications such as pumping water from wells, aquarium filtering, pond filtering and aeration, in the car industry for water-cooling and fuel injection, in the energy industry for pumping oil and natural gas or for operating cooling towers. In the medical industry, pumps are used for biochemical processes in developing and manufacturing medicine, and as artificial replacements for body parts, in particular the artificial heart and penile prosthesis.

In biology, many different types of chemical and bio-mechanical pumps have evolved, and biomimicry is sometimes used in developing new types of mechanical pumps.

 

Contents

• Types
  • Positive displacement pump
    • Positive displacement pump behavior and safety
    • Positive displacement types
      • Rotary positive displacement pumps
      • Reciprocating positive displacement pumps
      • Various positive displacement pumps
        • Gear pump
        • Screw pump
        • Progressing cavity pump
        • Roots-type pumps
        • Peristaltic pump
        • Plunger pumps
        • Triplex-style plunger pumps
        • Compressed-air-powered double-diaphragm pumps
        • Rope pumps
  • Impulse pumps
    • Hydraulic ram pumps
  • Velocity pumps
    • Radial-flow pumps
    • Axial-flow pumps
    • Mixed-flow pumps
    • Eductor-jet pump
  • Gravity pumps
  • Steam pumps
  • Valveless pumps
• 2Pump repairs
• 3Applications
  • Priming a pump
  • Pumps as public water supplies
  • Sealing multiphase pumping applications
    • Types and features of multiphase pumps
• Specifications
• Pumping power
• Pump efficiency
• See also
• References
• Further reading
• External links

4.1 Types

Mechanical pumps may be submerged in the fluid they are pumping or be placed external to the fluid.

Pumps can be classified by their method of displacement into positive displacement pumps, impulse pumps, velocity pumps, gravity pumps, steam pumps and valveless pumps. There are two basic types of pumps: positive displacement and centrifugal. Although axial-flow pumps are frequently classified as a separate type, they have essentially the same operating principles as centrifugal pumps.[2]

Positive displacement pump[edit]

  

Lobe pump internals

A positive displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe.

Some positive displacement pumps use an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation.

Positive displacement pump behavior and safety[edit]

Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, theoretically can produce the same flow at a given speed (RPM) no matter what the discharge pressure. Thus, positive displacement pumps are constant flow machines. However, a slight increase in internal leakage as the pressure increases prevents a truly constant flow rate.

A positive displacement pump must not operate against a closed valve on the discharge side of the pump, because it has no shutoff head like centrifugal pumps. A positive displacement pump operating against a closed discharge valve continues to produce flow and the pressure in the discharge line increases until the line bursts, the pump is severely damaged, or both.

A relief or safety valve on the discharge side of the positive displacement pump is therefore necessary. The relief valve can be internal or external. The pump manufacturer normally has the option to supply internal relief or safety valves. The internal valve is usually only used as a safety precaution. An external relief valve in the discharge line, with a return line back to the suction line or supply tank provides increased safety.

Positive displacement types[edit]

A positive displacement pump can be further classified according to the mechanism used to move the fluid:

• Rotary-type positive displacement: internal gear, screw, shuttle block, flexible vane or sliding vane, circumferential piston, flexible impeller, helical twisted roots (e.g. the Wendelkolben pump) or liquid ring vacuum pumps
• Reciprocating-type positive displacement: piston or diaphragm pumps
• Linear-type positive displacement: rope pumps and chain pumps

Rotary positive displacement pumps[edit]

  

Rotary vane pump

These pumps move fluid using a rotating mechanism that creates a vacuum that captures and draws in the liquid[citation needed][dubious – discuss].

Advantages: Rotary pumps are very efficient[citation needed] because they naturally remove air from the lines, eliminating the need to bleed the air from the lines manually.

Drawbacks: The nature of the pump demands very close clearances between the rotating pump and the outer edge, making it rotate at a slow, steady speed. If rotary pumps are operated at high speeds, the fluids cause erosion, which eventually causes enlarged clearances that liquid can pass through, which reduces efficiency.

Rotary positive displacement pumps fall into three main types:

• Gear pumps – a simple type of rotary pump where the liquid is pushed between two gears
• Screw pumps – the shape of the internals of this pump is usually two screws turning against each other to pump the liquid
• Rotary vane pumps – similar to scroll compressors, these have a cylindrical rotor encased in a similarly shaped housing. As the rotor orbits, the vanes trap fluid between the rotor and the casing, drawing the fluid through the pump.

Reciprocating positive displacement pumps[edit]

  

Simple hand pump

  

Old hand water pump (c. 1924) at the Colored School in Alapaha, Georgia, US

 Reciprocating pump

Reciprocating pumps move the fluid using one or more oscillating pistons, plungers, or membranes (diaphragms), while valves restrict fluid motion to the desired direction.

Pumps in this category range from simplex, with one cylinder, to in some cases quad (four) cylinders, or more. Many reciprocating-type pumps are duplex (two) or triplex (three) cylinder. They can be either single-acting with suction during one direction of piston motion and discharge on the other, or double-acting with suction and discharge in both directions. The pumps can be powered manually, by air or steam, or by a belt driven by an engine. This type of pump was used extensively in the 19th century—in the early days of steam propulsion—as boiler feed water pumps. Now reciprocating pumps typically pump highly viscous fluids like concrete and heavy oils, and serve in special applications that demand low flow rates against high resistance. Reciprocating hand pumps were widely used to pump water from wells. Common bicycle pumps and foot pumps for inflation use reciprocating action.

These positive displacement pumps have an expanding cavity on the suction side and a decreasing cavity on the discharge side. Liquid flows into the pumps as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant given each cycle of operation.

Typical reciprocating pumps are:

• Plunger pumps – a reciprocating plunger pushes the fluid through one or two open valves, closed by suction on the way back.
• Diaphragm pumps – similar to plunger pumps, where the plunger pressurizes hydraulic oil which is used to flex a diaphragm in the pumping cylinder. Diaphragm valves are used to pump hazardous and toxic fluids.
• Piston pumps displacement pumps – usually simple devices for pumping small amounts of liquid or gel manually. The common hand soap dispenser is such a pump.
• Radial piston pumps

Various positive displacement pumps

The positive displacement principle applies in these pumps:

• Rotary lobe pump
• Progressive cavity pump
• Rotary gear pump
• Piston pump
• Diaphragm pump
• Screw pump
• Gear pump
• Hydraulic pump
• Rotary vane pump
• Peristaltic pump
• Rope pump
• Flexible impeller pump

Gear pump

  

Gear pump

This is the simplest of rotary positive displacement pumps. It consists of two meshed gears that rotate in a closely fitted casing. The tooth spaces trap fluid and force it around the outer periphery. The fluid does not travel back on the meshed part, because the teeth mesh closely in the center. Gear pumps see wide use in car engine oil pumps and in various hydraulic power packs.

Screw pump[edit]

  

Screw pump

Main article: Screw pump

A screw pump is a more complicated type of rotary pump that uses two or three screws with opposing thread — e.g., one screw turns clockwise and the other counterclockwise. The screws are mounted on parallel shafts that have gears that mesh so the shafts turn together and everything stays in place. The screws turn on the shafts and drive fluid through the pump. As with other forms of rotary pumps, the clearance between moving parts and the pump’s casing is minimal.

Progressing cavity pump

Widely used for pumping difficult materials, such as sewage sludge contaminated with large particles, this pump consists of a helical rotor, about ten times as long as its width. This can be visualized as a central core of diameter x with, typically, a curved spiral wound around of thickness halfx, though in reality it is manufactured in single casting. This shaft fits inside a heavy duty rubber sleeve, of wall thickness also typically x. As the shaft rotates, the rotor gradually forces fluid up the rubber sleeve. Such pumps can develop very high pressure at low volumes.

  

Roots-type pumps[edit]

  

A Roots lobe pump

Main article: Roots-type supercharger

Named after the Roots brothers who invented it, this lobe pump displaces the liquid trapped between two long helical rotors, each fitted into the other when perpendicular at 90°, rotating inside a triangular shaped sealing line configuration, both at the point of suction and at the point of discharge. This design produces a continuous flow with equal volume and no vortex. It can work at low pulsation rates, and offers gentle performance that some applications require.

Applications include:

• High capacity industrial air compressors
• Roots superchargers on internal combustion engines.
• A brand of civil defense siren, the Federal Signal Corporation‘s Thunderbolt.

Peristaltic pump

  

360° Peristaltic Pump

Main article: Peristaltic pump

A peristaltic pump is a type of positive displacement pump. It contains fluid within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A number of rollers, shoes, or wipers attached to a rotor compresses the flexible tube. As the rotor turns, the part of the tube under compression closes (or occludes), forcing the fluid through the tube. Additionally, when the tube opens to its natural state after the passing of the cam it draws (restitution) fluid into the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract.

 

Plunger pumps

Plunger pumps are reciprocating positive displacement pumps.

These consist of a cylinder with a reciprocating plunger. The suction and discharge valves are mounted in the head of the cylinder. In the suction stroke the plunger retracts and the suction valves open causing suction of fluid into the cylinder. In the forward stroke the plunger pushes the liquid out of the discharge valve. Efficiency and common problems: With only one cylinder in plunger pumps, the fluid flow varies between maximum flow when the plunger moves through the middle positions, and zero flow when the plunger is at the end positions. A lot of energy is wasted when the fluid is accelerated in the piping system. Vibration and water hammer may be a serious problem. In general the problems are compensated for by using two or more cylinders not working in phase with each other.

Triplex-style plunger pumps

Triplex plunger pumps use three plungers, which reduces the pulsation of single reciprocating plunger pumps. Adding a pulsation dampener on the pump outlet can further smooth the pump ripple, or ripple graph of a pump transducer. The dynamic relationship of the high-pressure fluid and plunger generally requires high-quality plunger seals. Plunger pumps with a larger number of plungers have the benefit of increased flow, or smoother flow without a pulsation dampener. The increase in moving parts and crankshaft load is one drawback.

Car washes often use these triplex-style plunger pumps (perhaps without pulsation dampeners). In 1968, William Bruggeman significantly reduced the size of the triplex pump and increased the lifespan so that car washes could use equipment with smaller footprints. Durable high pressure seals, low pressure seals and oil seals, hardened crankshafts, hardened connecting rods, thick ceramic plungers and heavier duty ball and roller bearings improve reliability in triplex pumps. Triplex pumps now are in a myriad of markets across the world.

Triplex pumps with shorter lifetimes are commonplace to the home user. A person who uses a home pressure washer for 10 hours a year may be satisfied with a pump that lasts 100 hours between rebuilds. Industrial-grade or continuous duty triplex pumps on the other end of the quality spectrum may run for as much as 2,080 hours a year.

The oil and gas drilling industry uses massive semi trailer-transported triplex pumps called mud pumps to pump drilling mud, which cools the drill bit and carries the cuttings back to the surface.[3] Drillers use triplex or even quintuplex pumps to inject water and solvents deep into shale in the extraction process called fracking.[4]

Compressed-air-powered double-diaphragm pump

One modern application of positive displacement diaphragm pumps is compressed-air-powered double-diaphragm pumps. Run on compresseair these pumps are intrinsically safe by design, although all manufacturers offer ATEX certified models to comply with industry regulation. These pumps are relatively inexpensive and can perform a wide variety of duties, from pumping water out of bunds, to pumping hydrochloric acid from secure storage (dependent on how the pump is manufactured – elastomers / body construction). Lift is normally limited to roughly 6m although heads can reach almost 200 psi (1.4 MPa).[citation needed]

Rope pumps

  

Rope pump schematic

Main article: Rope pump

Devised in China as chain pumps over 1000 years ago, these pumps can be made from very simple materials: A rope, a wheel and a PVC pipe are sufficient to make a simple rope pump. For this reason they have become extremely popular around the world since the 1980s. Rope pump efficiency has been studied by grass roots organizations and the techniques for making and running them have been continuously improved.[5]

Impulse pumps

Impulse pumps use pressure created by gas (usually air). In some impulse pumps the gas trapped in the liquid (usually water), is released and accumulated somewhere in the pump, creating a pressure that can push part of the liquid upwards.

Conventional impulse pumps include:

• Hydraulic ram pumps – kinetic energy of a low-head water supply is stored temporarily in an air-bubble hydraulic accumulator, then used to drive water to a higher head.
• Pulser pumps – run with natural resources, by kinetic energy only.
• Airlift pumps – run on air inserted into pipe, which pushes the water up when bubbles move upward

Instead of a gas accumulation and releasing cycle, the pressure can be created by burning of hydrocarbons. Such combustion driven pumps directly transmit the impulse form a combustion event through the actuation membrane to the pump fluid. In order to allow this direct transmission, the pump needs to be almost entirely made of an elastomer (e.g. silicone rubber). Hence, the combustion causes the membrane to expand and thereby pumps the fluid out of the adjacent pumping chamber. The first combustion-driven soft pump was developed by ETH Zurich.[6]

Hydraulic ram pumps

A hydraulic ram is a water pump powered by hydropower.

It takes in water at relatively low pressure and high flow-rate and outputs water at a higher hydraulic-head and lower flow-rate. The device uses the water hammer effect to develop pressure that lifts a portion of the input water that powers the pump to a point higher than where the water started.

The hydraulic ram is sometimes used in remote areas, where there is both a source of low-head hydropower, and a need for pumping water to a destination higher in elevation than the source. In this situation, the ram is often useful, since it requires no outside source of power other than the kinetic energy of flowing water.

Velocity pumps

  

A centrifugal pump uses an impellerwith backward-swept arms

Rotodynamic pumps (or dynamic pumps) are a type of velocity pump in which kinetic energy is added to the fluid by increasing the flow velocity. This increase in energy is converted to a gain in potential energy (pressure) when the velocity is reduced prior to or as the flow exits the pump into the discharge pipe. This conversion of kinetic energy to pressure is explained by the First law of thermodynamics, or more specifically by Bernoulli’s principle.

Dynamic pumps can be further subdivided according to the means in which the velocity gain is achieved.

These types of pumps have a number of characteristics:

1. Continuous energy
2. Conversion of added energy to increase in kinetic energy (increase in velocity)
3. Conversion of increased velocity (kinetic energy) to an increase in pressure head

A practical difference between dynamic and positive displacement pumps is how they operate under closed valve conditions. Positive displacement pumps physically displace fluid, so closing a valve downstream of a positive displacement pump produces a continual pressure build up that can cause mechanical failure of pipeline or pump. Dynamic pumps differ in that they can be safely operated under closed valve conditions (for short periods of time).

Radial-flow pumps

These are also referred to as centripetal design pumps. The fluid enters along the axis or center, is accelerated by the impeller and exits at right angles to the shaft(radially). Radial-flow pumps operate at higher pressures and lower flow rates than axial- and mixed-flow pumps.

Axial-flow pumps

These are also referred to as All fluid pumps The fluid is pushed outward or inward and move fluid axially. They operate at much lower pressures and higher flow rates than radial-flow (centripetal) pumps.

Mixed-flow pumps

Mixed-flow pumps function as a compromise between radial and axial-flow pumps. The fluid experiences both radial acceleration and lift and exits the impeller somewhere between 0 and 90 degrees from the axial direction. As a consequence mixed-flow pumps operate at higher pressures than axial-flow pumps while delivering higher discharges than radial-flow pumps. The exit angle of the flow dictates the pressure head-discharge characteristic in relation to radial and mixed-flow.

Eductor-jet pump

This uses a jet, often of steam, to create a low pressure. This low pressure sucks in fluid and propels it into a higher pressure region.

Gravity pumps

Gravity pumps include the syphon and Heron’s fountain. The hydraulic ram is also sometimes called a gravity pump; in a gravity pump the water is lifted by gravitational force.

Steam pumps

Steam pumps have been for a long time mainly of historical interest. They include any type of pump powered by a steam engine and also pistonless pumps such as Thomas Savery‘s or the Pulsometer steam pump.

Recently there has been a resurgence of interest in low power solar steam pumps for use in smallholder irrigation in developing countries. Previously small steam engines have not been viable because of escalating inefficiencies as vapour engines decrease in size. However the use of modern engineering materials coupled with alternative engine configurations has meant that these types of system are now a cost effective opportunity.

Valveless pumps

Valveless pumping assists in fluid transport in various biomedical and engineering systems. In a valveless pumping system, no valves (or physical occlusions) are present to regulate the flow direction. The fluid pumping efficiency of a valveless system, however, is not necessarily lower than that having valves. In fact, many fluid-dynamical systems in nature and engineering more or less rely upon valveless pumping to transport the working fluids therein. For instance, blood circulation in the cardiovascular system is maintained to some extent even when the heart’s valves fail. Meanwhile, the embryonic vertebrate heart begins pumping blood long before the development of discernible chambers and valves. In microfluidics, valveless impedance pumps have been fabricated, and are expected to be particularly suitable for handling sensitive biofluids. Ink jet printers operating on the Piezoelectric transducer principle also use valveless pumping. The pump chamber is emptied through the printing jet due to reduced flow impedance in that direction and refilled by capillary action..

Pump repairs

Examining pump repair records and mean time between failures (MTBF) is of great importance to responsible and conscientious pump users. In view of that fact, the preface to the 2006 Pump User’s Handbook alludes to “pump failure” statistics. For the sake of convenience, these failure statistics often are translated into MTBF (in this case, installed life before failure).[8]

In early 2005, Gordon Buck, John Crane Inc.’s chief engineer for Field Operations in Baton Rouge, LA, examined the repair records for a number of refinery and chemical plants to obtain meaningful reliability data for centrifugal pumps. A total of 15 operating plants having nearly 15,000 pumps were included in the survey. The smallest of these plants had about 100 pumps; several plants had over 2000. All facilities were located in the United States. In addition, considered as “new”, others as “renewed” and still others as “established”. Many of these plants—but not all—had an alliance arrangement with John Crane. In some cases, the alliance contract included having a John Crane Inc. technician or engineer on-site to coordinate various aspects of the program.

Not all plants are refineries, however, and different results occur elsewhere. In chemical plants, pumps have traditionally been “throw-away” items as chemical attack limits life. Things have improved in recent years, but the somewhat restricted space available in “old” DIN and ASME-standardized stuffing boxes places limits on the type of seal that fits. Unless the pump user upgrades the seal chamber, the pump only accommodates more compact and simple versions. Without this upgrading, lifetimes in chemical installations are generally around 50 to 60 percent of the refinery values.

Unscheduled maintenance is often one of the most significant costs of ownership, and failures of mechanical seals and bearings are among the major causes. Keep in mind the potential value of selecting pumps that cost more initially, but last much longer between repairs. The MTBF of a better pump may be one to four years longer than that of its non-upgraded counterpart. Consider that published average values of avoided pump failures range from US$2600 to US$12,000. This does not include lost opportunity costs. One pump fire occurs per 1000 failures. Having fewer pump failures means having fewer destructive pump fires.

As has been noted, a typical pump failure based on actual year 2002 reports, costs US$5,000 on average. This includes costs for material, parts, labor and overhead. Extending a pump’s MTBF from 12 to 18 months would save US$1,667 per year — which might be greater than the cost to upgrade the centrifugal pump’s reliability.

Applications

  

Metering pump for gasoline andadditives.

Pumps are used throughout society for a variety of purposes. Early applications includes the use of the windmill or watermill to pump water. Today, the pump is used for irrigation, water supply, gasoline supply, air conditioning systems, refrigeration (usually called a compressor), chemical movement, sewage movement, flood control, marine services, etc.

Because of the wide variety of applications, pumps have a plethora of shapes and sizes: from very large to very small, from handling gas to handling liquid, from high pressure to low pressure, and from high volume to low volume.

Priming a pump

Typically, a liquid pump can’t simply draw air. The feed line of the pump and the internal body surrounding the pumping mechanism must first be filled with the liquid that requires pumping: An operator must introduce liquid into the system to initiate the pumping. This is called priming the pump. Loss of prime is usually due to ingestion of air into the pump. The clearances and displacement ratios in pumps for liquids, whether thin or more viscous, usually cannot displace air due to its compressibility. This is the case with most velocity (rotodynamic) pumps — for example, centrifugal pumps.

Positive–displacement pumps, however, tend to have sufficiently tight sealing between the moving parts and the casing or housing of the pump that they can be described asself-priming. Such pumps can also serve as priming pumps, so called when they are used to fulfill that need for other pumps in lieu of action taken by a human operator.

One sort of pump once common worldwide was a hand-powered water pump, or ‘pitcher pump’. It was commonly installed over community water wells in the days before piped water supplies.

In parts of the British Isles, it was often called the parish pump. Though such community pumps are no longer common, people still used the expression parish pump to describe a place or forum where matters of local interest are discussed.[12]

Because water from pitcher pumps is drawn directly from the soil, it is more prone to contamination. If such water is not filtered and purified, consumption of it might lead to gastrointestinal or other water-borne diseases. A notorious case is the 1854 Broad Street cholera outbreak. At the time it was not known how cholera was transmitted, but physician John Snow suspected contaminated water and had the handle of the public pump he suspected removed; the outbreak then subsided.

Modern hand-operated community pumps are considered the most sustainable low-cost option for safe water supply in resource-poor settings, often in rural areas in developing countries. A hand pump opens access to deeper groundwater that is often not polluted and also improves the safety of a well by protecting the water source from contaminated buckets. Pumps such as the Afridev pump are designed to be cheap to build and install, and easy to maintain with simple parts. However, scarcity of spare parts for these type of pumps in some regions of Africa has diminished their utility for these areas.

Sealing multiphase pumping applications

Multiphase pumping applications, also referred to as tri-phase, have grown due to increased oil drilling activity. In addition, the economics of multiphase production is attractive to upstream operations as it leads to simpler, smaller in-field installations, reduced equipment costs and improved production rates. In essence, the multiphase pump can accommodate all fluid stream properties with one piece of equipment, which has a smaller footprint. Often, two smaller multiphase pumps are installed in series rather than having just one massive pump.

For midstream and upstream operations, multiphase pumps can be located o[13]nshore or offshore and can be connected to single or multiple wellheads. Basically, multiphase pumps are used to transport the untreated flow stream produced from oil wells to downstream processes or gathering facilities. This means that the pump may handle a flow stream (well stream) from 100 percent gas to 100 percent liquid and every imaginable combination in between. The flow stream can also contain abrasives such as sand and dirt. Multiphase pumps are designed to operate under changing/fluctuating process conditions. Multiphase pumping also helps eliminate emissions of greenhouse gases as operators strive to minimize the flaring of gas and the venting of tanks where possible.

Types and features of multiphase pumps

Helico-Axial Pumps (Centrifugal) A rotodynamic pump with one single shaft that requires two mechanical seals, this pump uses an open-type axial impeller. It’s often called aPoseidon pump, and can be described as a cross between an axial compressor and a centrifugal pump.

Twin Screw (Positive Displacement) The twin screw pump is constructed of two inter-meshing screws that move the pumped fluid. Twin screw pumps are often used when pumping conditions contain high gas volume fractions and fluctuating inlet conditions. Four mechanical seals are required to seal the two shafts.

Progressive Cavity Pumps (Positive Displacement) Progressive cavity pumps are single-screw types typically used in shallow wells or at the surface. This pump is mainly used on surface applications where the pumped fluid may contain a considerable amount of solids such as sand and dirt.

Electric Submersible Pumps (Centrifugal) These pumps are basically multistage centrifugal pumps and are widely used in oil well applications as a method for artificial lift. These pumps are usually specified when the pumped fluid is mainly liquid.

Buffer Tank A buffer tank is often installed upstream of the pump suction nozzle in case of a slug flow. The buffer tank breaks the energy of the liquid slug, smooths any fluctuations in the incoming flow and acts as a sand trap.

As the name indicates, multiphase pumps and their mechanical seals can encounter a large variation in service conditions such as changing process fluid composition, temperature variations, high and low operating pressures and exposure to abrasive/erosive media. The challenge is selecting the appropriate mechanical seal arrangement and support system to ensure maximized seal life and its overall effectiveness.

Specifications

Pumps are commonly rated by horsepower, flow rate, outlet pressure in metres (or feet) of head, inlet suction in suction feet (or metres) of head. The head can be simplified as the number of feet or metres the pump can raise or lower a column of water at atmospheric pressure.

From an initial design point of view, engineers often use a quantity termed the specific speed to identify the most suitable pump type for a particular combination of flow rate and head.

Pumping power

Bernoulli’s equation

The power imparted into a fluid increases the energy of the fluid per unit volume. Thus the power relationship is between the conversion of the mechanical energy of the pump mechanism and the fluid elements within the pump. In general, this is governed by a series of simultaneous differential equations, known as the Navier–Stokes equations. However a more simple equation relating only the different energies in the fluid, known as Bernoulli’s equation can be used. Hence the power, P, required by the pump:

where Δp is the change in total pressure between the inlet and outlet (in Pa), and Q, the volume flow-rate of the fluid is given in m3/s. The total pressure may have gravitational,static pressure and kinetic energy components; i.e. energy is distributed between change in the fluid’s gravitational potential energy (going up or down hill), change in velocity, or change in static pressure. η is the pump efficiency, and may be given by the manufacturer’s information, such as in the form of a pump curve, and is typically derived from either fluid dynamics simulation (i.e. solutions to the Navier–Stokes for the particular pump geometry), or by testing. The efficiency of the pump depends upon the pump’s configuration and operating conditions (such as rotational speed, fluid density and viscosity etc.)

For a typical “pumping” configuration, the work is imparted on the fluid, and is thus positive. For the fluid imparting the work on the pump (i.e. a turbine), the work is negative. Power required to drive the pump is determined by dividing the output power by the pump efficiency. Furthermore, this definition encompasses pumps with no moving parts, such as a siphon.

Pump efficiency

Pump efficiency is defined as the ratio of the power imparted on the fluid by the pump in relation to the power supplied to drive the pump. Its value is not fixed for a given pump, efficiency is a function of the discharge and therefore also operating head. For centrifugal pumps, the efficiency tends to increase with flow rate up to a point midway through the operating range (peak efficiency) and then declines as flow rates rise further. Pump performance data such as this is usually supplied by the manufacturer before pump selection. Pump efficiencies tend to decline over time due to wear (e.g. increasing clearances as impellers reduce in size).

When a system design includes a centrifugal pump, an important issue it its design is matching the head loss-flow characteristic with the pump so that it operates at or close to the point of its maximum efficiency.

Pump efficiency is an important aspect and pumps should be regularly tested. Thermodynamic pump testing is one method.

Bibliography:

www.google.com

www.wikipedia.com

http://www.aspee.com/