1.a mechanical device that moves fluid or gas by pressure or suction
2.a low-cut shoe without fastenings
3.the hollow muscular organ located behind the sternum and between the lungs; its rhythmic contractions move the blood through the body"he stood still, his heart thumping wildly"
1.question persistently"She pumped the witnesses for information"
2.deliver forth"pump bullets into the dummy"
3.operate like a pump; move up and down, like a handle or a pedal"pump the gas pedal"
4.raise (gases or fluids) with a pump
5.move up and down"The athlete pumps weights in the gym"
6.draw or pour with a pump
8.supply in great quantities"Pump money into a project"
PumpPump (pŭmp), n. [Probably so called as being worn for pomp or ornament. See Pomp.] A low shoe with a thin sole. Swift.
PumpPump, n. [Akin to D. pomp, G. pumpe, F. pompe; of unknown origin.] An hydraulic machine, variously constructed, for raising or transferring fluids, consisting essentially of a moving piece or piston working in a hollow cylinder or other cavity, with valves properly placed for admitting or retaining the fluid as it is drawn or driven through them by the action of the piston.
☞ for various kinds of pumps, see Air pump, Chain pump, and Force pump; also, under Lifting, Plunger, Rotary, etc.
Circulating pump (Steam Engine), a pump for driving the condensing water through the casing, or tubes, of a surface condenser. -- Pump brake. See Pump handle, below. -- Pump dale. See Dale. -- Pump gear, the apparatus belonging to a pump. Totten. -- Pump handle, the lever, worked by hand, by which motion is given to the bucket of a pump. -- Pump hood, a semicylindrical appendage covering the upper wheel of a chain pump. -- Pump rod, the rod to which the bucket of a pump is fastened, and which is attached to the brake or handle; the piston rod. -- Pump room, a place or room at a mineral spring where the waters are drawn and drunk. [Eng.] -- Pump spear. Same as Pump rod, above. -- Pump stock, the stationary part, body, or barrel of a pump. -- Pump well. (Naut.) See Well.
PumpPump, v. t. [imp. & p. p. Pumped (pŭmt; 215); p. pr. & vb. n. pumping.]
1. To raise with a pump, as water or other liquid.
2. To draw water, or the like, from; to from water by means of a pump; as, they pumped the well dry; to pump a ship.
3. Figuratively, to draw out or obtain, as secrets or money, by persistent questioning or plying; to question or ply persistently in order to elicit something, as information, money, etc.
But pump not me for politics. Otway.
PumpPump, v. i. To work, or raise water, a pump.
definition of Wikipedia
Pump, Biologic • Pump, Biological • Pump, Metabolic • Pump, Programmable Implantable Insulin • air pump • air-pump • gas pump • hand pump • oil pump • pump across • pump action • pump compass • pump cover • pump house • pump money in • pump out • pump over • pump priming • pump room • pump shop • pump station • pump up • pump well • pump works • pump-and-dump scheme • pump-house • pump-type pliers • water pump
Absorption heat pump • Airlift pump • Aldgate Pump • An Experiment on a Bird in the Air Pump • An Experiment with an Air Pump • Anna Pump • Axial flow pump • Axial piston pump • Bicycle pump • Bilge pump • Biological pump • Black Pump Power Station • Blake and Knowles Steam Pump Company National Register District • Blood pump • Boiler feedwater pump • Breast pump • CTS charge pump • Calcium pump • Centrifugal pump • Chain pump • Charge pump • Circulator pump • Clitoral pump • Compression pump • Concrete pump • Condensate pump • Cyclic pump • Da Pump • Da Pump discography • Desoldering pump • Diaphragm pump • Diffusion pump • Direct exchange geothermal heat pump • Diver's pump • Downton pump • Eductor-jet pump • Electroosmotic pump • Fall River Pump House and Catchment Basin • Fire pump • Fist pump • Follower plate pump • Fuel pump • Gas Pump Girls • Geothermal heat pump • Grinder pump • Hand pump • Heat pump • Heat pump and refrigeration cycle • Hose pump • Hydraulic pump • Illinois Central Railroad Water Tower and Pump House • Impulse pump • Inductive Pump • Infusion pump • Injection pump • Inline pump • Insulin pump • Intelligent pump • Intra-aortic balloon pump • Intrathecal pump • Intuition pump • Ion pump (physics) • Kearny Air Pump • List of Pump it Up games • Lobe pump • Lymphatic pump • Manual pump • Manual water pump • Mary Jane pump • Merry-go-round water pump • Metering pump • Mud pump • Na+/Ca++ pump • Na+/Ca2+ pump • Off-pump coronary artery bypass • Oil pump • Oil pump (internal combustion engine) • Old Lock Pump House, Chesapeake and Delaware Canal • Parish Pump (CGA series) • Paxton Water Tower and Pump House • Pay at the pump • Peristaltic pump • Petrol pump • Phase change heat pump • Pistonless pump • Pittville Pump Room • Plunger pump • Progressive cavity pump • Protein pump • Proton pump • Proton-pump inhibitor • Pulsometer steam pump • Pump (album) • Pump (band) • Pump (disambiguation) • Pump (shoe) • Pump (skateboarding) • Pump Back, Oklahoma • Pump Boys and Dinettes • Pump Branch • Pump Friction • Pump Geyser • Pump Girls • Pump House Brewery • Pump House, Bristol • Pump It • Pump It Up • Pump It Up (Elvis Costello song) • Pump It Up (Joe Budden song) • Pump It Up NX • Pump It Up NX Absolute • Pump It Up NX2 • Pump It Up Pro • Pump It Up Zero • Pump Octane Number • Pump Tour • Pump Up the Jam • Pump Up the Valuum • Pump Up the Volume • Pump Up the Volume (song) • Pump Ya Fist • Pump and dump • Pump and run • Pump boat • Pump fake • Pump leak model • Pump octance number • Pump octane number • Pump performance • Pump station manager • Pump testing • Pump toothpaste • Pump trolley • Pump-Kin Music • Pump-Pump • Pump-action • Pump-action shotgun • Pump-jack • Pump-jet • Radial piston pump • Ram pump • Reality Pump Studios • Reciprocating pump • Reebok Pump • Rope pump • Rotary vane pump • Rotodynamic pump • Roughing pump • Roundabout water pump • Royal Pump Room Gardens • Royal Pump Rooms • Rudy's Pump Room • Sahara pump theory • Scroll vacuum pump • Shit pump • Short Pump • Short Pump (disambiguation) • Short Pump Elementary School • Short Pump Middle School • Short Pump Town Center • Short Pump, Virginia • Skeletal-muscle pump • Sodium calcium exchange pump • Sodium calcium pump • Sodium-calcium exchange pump • Sodium-calcium pump • Solar pump • Solar-powered pump • Sorption pump • Sprengel pump • Submersible pump • The Making of Pump • The Pump House Gang • Thermodynamic pump testing • Things That Go Pump in the Night • Titanium sublimation pump • Toepler pump • Toothpaste pump • Town Pump • Transmembrane pump • Treadle pump • Triathlon (heat pump) • Trowbridge Village Pump Festival • Turbo pump • Turbomolecular pump • Unit pump • Vacuum pump • Variable displacement pump • Vico pump • Void pump • Volute (pump) • Walthamstow Pump House Museum • Water Pump • Water pump bearing • Water well pump • Wendelkolben pump • Wikipedia Village Pump • Wood Screw Pump • World Pump Festival
ouvrage hydraulique (fr)[Classe]
lieu où se trouve de l'eau (fr)[Classe]
récipient ouvert (fr)[Classe]
objet métallique (fr)[ClasseParExt.]
chose composée de cuivre (fr)[ClasseParExt.]
machine hydraulique (fr)[Classe]
machine : par domaine d'usage (fr)[Classe...]
objet en cuivre (fr)[ClasseParExt.]
outil pour jeter de l'eau (fr)[Classe]
chose en cuir ou peau (fr)[ClasseParExt.]
organ; fabric; tissue[Classe]
système sanguin (fr)[DomainDescrip.]
tronc de l'homme (fr)[DomainDescrip.]
variety meat; organs; offal[ClasseParExt.]
heart; pump; ticker[ClasseHyper.]
pump (v. tr.) [colloquial]
pump (v. tr.)
enquiry, inquiry, interrogation, query, question, question mark - inquiring, questioning - interrogation, interrogative, interrogative sentence, question - asker, enquirer, inquirer, querier, questioner[Dérivé]
ask, challenge, query, question[Hyper.]
pump (v. tr.)
hit, pip, shoot[Domaine]
pump (v. tr.)
pump (v. tr.)
heave, lift, raise - air bridge, airlift, lift - elevator, hoist, lift - lift - lift, ski lift, ski tow - elevation - lift, rise - elevation, lift, raising - acclivity, ascent, climb, raise, rise, upgrade - elevation, natural elevation - lifter, weightlifter, weight-lifter - pump - pump - pump[Dérivé]
bring, convey, take[Analogie]
pump (v. tr.)
action, motion, move, movement - movement - mover, moving company, public mover, removal company, removal firm - mover - movable, moveable, transferable, transferrable, transportable - movable[Dérivé]
go, go along, locomote, move, travel[Domaine]
pump (v. tr.)
pump (v. tr.)
gush, spirt, spout, spurt[Hyper.]
pump (v. tr.)
pump (v. tr.)
A pump is a device used to move 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.
Pumps must have a mechanism which operates them, and consume energy to perform mechanical work by moving the fluid. The activating mechanism is often reciprocating or rotary. Pumps may be operated in many ways, including manual operation, electricity, an engine of some type, or wind action.
A positive displacement pump causes a fluid to move by trapping a fixed amount of it and then forcing (displacing) that trapped volume into the discharge pipe.
Some positive displacement pumps work using 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 given each cycle of operation.
Positive displacement pumps, unlike centrifugal or roto-dynamic pumps, will in theory produce the same flow at a given speed (RPM) no matter what the discharge pressure. Thus, positive displacement pumps are "constant flow machines". However due to a slight increase in internal leakage as the pressure increases, a truly constant flow rate cannot be achieved.
A positive displacement pump must not be operated against a closed valve on the discharge side of the pump, because it has no shut-off head like centrifugal pumps. A positive displacement pump operating against a closed discharge valve will continue to produce flow and the pressure in the discharge line will increase, until the line bursts or 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 should in general only be used as a safety precaution, an external relief valve installed in the discharge line with a return line back to the suction line or supply tank is recommended.
A positive displacement pump can be further classified according to the mechanism used to move the fluid:
Positive displacement rotary pumps move fluid have a rotating mechanism that creates a vacuum that captures and draws in the liquid.
Advantages: Rotary pumps are very efficient because they naturally remove air from the lines, eliminating the need to bleed the air from the lines manually.
Drawbacks: Because of the nature of the pump, the clearance between the rotating pump and the outer edge must be very close, requiring that it rotate at a slow, steady speed. If rotary pumps are operated at high speeds, the fluids will cause erosion, eventually developing enlarged clearances through which liquid can pass, reducing the efficiency of the pump.
Rotary positive displacement pumps can be grouped into three main types:
Reciprocating pumps are those which cause the fluid to move using one or more oscillating pistons, plungers or membranes (diaphragms), and restrict motion of the fluid to the one desired direction by valves.
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 early days of steam propulsion (19th century) as boiler feed water pumps. Reciprocating pumps are now typically used for pumping highly viscous fluids including concrete and heavy oils, and special applications demanding low flow rates against high resistance. Reciprocating hand pumps were widely used for pumping water from wells; the common bicycle pump 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:
The positive displacement principle applies in the following types of pumps:
This is the simplest of rotary positive displacement pumps. It consists of two meshed gears rotating in a closely fitted casing. Fluid is pumped around the outer periphery by being trapped in the tooth spaces. It does not travel back on the meshed part, since the teeth mesh closely in the centre. It is widely used on car engine oil pumps, and also in various hydraulic power packs.
Screw pumps are a more complicated type of rotary pumps, featuring two or three screws with opposing thread —- that is, one screw turns clockwise, and the other counterclockwise. The screws are each mounted on shafts that run parallel to each other; the shafts also have gears on them that mesh with each other in order to turn the shafts together and keep everything in place. The turning of the screws, and consequently the shafts to which they are mounted, draws the fluid through the pump. As with other forms of rotary pumps, the clearance between moving parts and the pump's casing is minimal.
Widely used for pumping difficult materials such as sewage sludge contaminated with large particles, this pump consists of a helical shaped 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 half x, although of course in reality it is made from one casting. This shaft fits inside a heavy duty rubber sleeve, of wall thickness typically x also. As the shaft rotates, fluid is gradually forced up the rubber sleeve. Such pumps can develop very high pressure at quite low volumes.
Named after the Roots brothers who designed and invented it, this lobe pump works by displacing the liquid trapped between two long helical twisted rotors, each fitting 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 results with gentle performance, more fit for some applications.
Some applications are:
A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids. The fluid is contained within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A rotor with a number of "rollers", "shoes" or "wipers" attached to the external circumference compresses the flexible tube. As the rotor turns, the part of the tube under compression closes (or "occludes") thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state after the passing of the cam ("restitution") fluid flow is induced to the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract.
Plunger pumps are reciprocating positive displacement pumps.
They consist of a cylinder with a reciprocating plunger in them. 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.
One modern application of positive displacement diaphragm pumps is compressed-air-powered double-diaphragm pumps. Run on compressed air these pumps are intrinsically safe by design, although all manufacturers offer ATEX certified models to comply with industry regulation. Commonly seen in all areas of industry from shipping to processing, Wilden Pumps, Graco, SandPiper or ARO are generally the larger of the brands. They are relatively inexpensive and can be used for almost any duty 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..
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.
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 which can push part of the liquid upwards.
Impulse pumps include:
A hydraulic ram is a water pump powered by hydropower.
It functions as a hydraulic transformer that takes in water at one "hydraulic head" (pressure) and 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 allows a portion of the input water that powers the pump to be lifted to a point higher than where the water originally 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.
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 can be 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:
One practical difference between dynamic and positive displacement pumps is their ability to operate under closed valve conditions. Positive displacement pumps physically displace the fluid; hence closing a valve downstream of a positive displacement pump will result in a continual build up in pressure resulting in mechanical failure of either pipeline or pump. Dynamic pumps differ in that they can be safely operated under closed valve conditions (for short periods of time).
A centrifugal pump is a rotodynamic pump that uses a rotating impeller to increase the pressure and flow rate of a fluid. Centrifugal pumps are the most common type of pump used to move liquids through a piping system. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flowing radially outward or axially into a diffuser or volute chamber, from where it exits into the downstream piping system. Centrifugal pumps are typically used for large discharge through smaller heads.
Centrifugal pumps are most often associated with the radial flow type. However, the term "centrifugal pump" can be used to describe all impeller type rotodynamic pumps including the radial, axial and mixed flow variations.
Often simply referred to as centrifugal pumps. The fluid enters along the axial plane, 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 differ from radial flow in that the fluid enters and exits along the same direction parallel to the rotating shaft. The fluid is not accelerated but instead "lifted" by the action of the impeller. They may be likened to a propeller spinning in a length of tube. Axial flow pumps operate at much lower pressures and higher flow rates than radial flow pumps.
Mixed flow pumps, as the name suggests, function as a compromise between radial and axial flow pumps, the fluid experiences both radial acceleration and lift and exits the impeller somewhere between 0–90 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.
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 include the syphon and Heron's fountain – and there also important qanat or foggara systems which simply use downhill flow to take water from far-underground aquifers in high areas to consumers at lower elevations. The hydraulic ram is also sometimes referred to as a gravity pump.
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, the Pulsometer steam pump or the Steam injection 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 pumping assists in fluid transport in various biomedical and engineering systems. In a valveless pumping system, no valves 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 discernable chambers and valves. In microfluidics, valveless impedance pump have been fabricated, and are expected to be particularly suitable for handling sensitive biofluids.
Examining pump repair records and MTBF (mean time between failures) 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).
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 can be expected elsewhere. In chemical plants, pumps have traditionally been "throw-away" items as chemical attack can result in limited 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 can be fitted. Unless the pump user upgrades the seal chamber, only the more compact and simple versions can be accommodated. Without this upgrading, lifetimes in chemical installations are generally believed to be 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 $2600 to $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 $5,000 on average. This includes costs for material, parts, labor and overhead. Let us now assume that the MTBF for a particular pump is 12 months and that it could be extended to 18 months. This would result in a cost avoidance of $2,500/yr—which is greater than the premium one would pay for the reliability-upgraded centrifugal pump.
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.
Liquid and slurry pumps can lose prime and this will require the pump to be primed by adding liquid to the pump and inlet pipes to get the pump started. Loss of "prime" is usually due to ingestion of air into the pump. The clearances and displacement ratios in pumps used for liquids and other more viscous fluids cannot displace the air due to its lower density.
One sort of pump once common worldwide was a hand-powered water pump, or 'pitcher pump'. It would be installed over a community water well that was used by people in the days before piped water supplies.
In parts of the British Isles, it was often called "the parish pump". Although such community pumps are no longer common, the expression "parish pump" is still used. It derives from the kind of the chatter and conversation that might be heard as people congregated to draw water from the community water pump, and is now used to describe a place or forum where matter of purely local interest is discussed.
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.
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 onshore 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.
Helico-Axial Pumps (Centrifugal) A rotodynamic pump with one single shaft requiring two mechanical seals. This pump utilizes an open-type axial impeller. This pump type is often referred to as a "Poseidon 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 intermeshing screws that force the movement of 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, smoothes 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.
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.
The pump material can be Stainless steel (SS 316 or SS 304), cast iron etc. It depends on the application of the pump. In the water industry and for pharma applications SS 316 is normally used, as stainless steel gives better results at high temperatures.
The power imparted into a fluid will increase 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 fluid flowrate is given in m^3/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 will depend 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 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).
One important part of system design involves matching the pipeline head loss-flow characteristic with the appropriate pump or pumps in order to operate at or close to the point of maximum efficiency.
Pump efficiency is an important aspect and pumps should be regularly tested. Thermodynamic pump testing is one method.
Pump selection is done by performance curve which is curve between pressure head and flow rate, with power supply also taken care of. Pumps are normally available that run at 50 Hz or 60 Hz.
To minimise energy use, and to ensure that pumps are correctly matched to the duty expected pumps, and pumping stations should be regularly tested.
In water supply application, which are usually fitted with centrifugal pumps, individual large pumps should be 70 - 80% efficient. They should be individually tested to ensure they are in the appropriate range, and replaced or prepared as appropriate.
Pumping stations should also be tested collectively, because where pumps can run in combination to meet a given demand, it is often possible for very inefficient combination of pumps to occur. For example. it is perfectly possible to have a large and a small pump operating in parallel, with the smaller pump not delivering any water, but merely consuming energy. See Pump station manager
Pumps are readily tested by fitting a flow meter, measuring the pressure difference between inlet and outlet, and measuring the power consumed.
Another method is thermodynamic pump testing where only the temperature rise and power consumed need be measured.
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