Pumps overview

A pump is a device used to move gases, liquids,the pump is used for irrigation, water supply, air
or slurries. A pump moves liquids or gases fromconditioning systems, refrigeration (usually called a
lower pressure to higher pressure, andcompressor), chemical movement, sewage
overcomes this difference in pressure by addingmovement, flood control, marine services, etc.
energy to the system (such as a water system).Because of the wide variety of applications,
A gas pump is generally called a compressor,pumps have a plethora of shapes and sizes: from
except in very low pressure-rise applications, suchvery large to very small, from handling gas to
as in heating, ventilating, and air-conditioning, thehandling liquid, from high pressure to low pressure,
equipment is known as fans or blowers.and from high volume to low volume.
The earliest pump was described by ArchimedesPower source
in the 3rd century BC and is known as the19th century Dutch diesel pump in Rijswijk,
Archimedes screw pump. Pumps work by usingNetherlands Domestic Central Heating PumpPumps
mechanical forces to push the material, either bymay be powered by an internal combustion
physically lifting, or by the force of compression.engine, electric motor, manually (as with the hand
Pumps fall into three categories: positivepump used for pumping groundwater, called
displacement, kinetic (centrifugal), and jetwalking beam pump), or by wind power (common
(eductor). Their names describe the method forfor irrigation). Solar power has been used to
moving a liquid, such as water.power an electric motor, for remote locations
A positive displacement pump causes a fluid toEductor-jet pumps are useful for draining areas
move by trapping a fixed volume of water andwhich may contain combustible fluids (which could
then forcing (displacement) that trapped volumeignite if exposed to the workings of a standard
into the receiving pipe. Positive displacementelectric or internal combustion powered pump) or
pumps can be further classified as eitherhigh levels of debris (which could damage screws
rotary-type (for example the rotary vane pump)or blades in conventional pump designs).
or reciprocating-type (for example the diaphragmA source of pressurized fluid (e.g. a firehose) is
pump).connected to a chamber which is open on one
A centrifugal pump causes a fluid to move byend, and leads to an exhaust hose on the other
transferring the kinetic (rotational) energy from aend. The pressurized fluid is forced through
motor (through an impeller) into water pressurenozzles (called eductor jets) mounted axially on
(potential energy).the inside of the pump chamber, pointed in the
A eductor-jet pump is special type of pumpdirection of the exhaust hose. The passage of the
without moving parts that uses the kinetic energypressurized fluid through the chamber and into the
of a fluid to increase the pressure of a secondexhaust hose creates a suction on the open end
fluid.of the chamber (Venturi effect), such that any
Applicationfluid the pump chamber has been submerged in
Pumps are used throughout society for a varietywill be drawn into the chamber and thence into
of purposes. Early applications includes the use ofthe exhaust hose along with the fluid from the
the windmill or watermill to pump water. Today,eductor jet nozzles.