| A pump is a device used to move gases, | | | | irrigation, water supply, air conditioning |
| liquids, or slurries. A pump moves liquids or | | | | systems, refrigeration (usually called a |
| gases from lower pressure to higher pressure, | | | | compressor), chemical movement, sewage |
| and overcomes this difference in pressure by | | | | movement, flood control, marine services, |
| adding energy to the system (such as a water | | | | etc. |
| system). A gas pump is generally called a | | | | |
| compressor, except in very low pressure-rise | | | | Because of the wide variety of applications, |
| applications, such as in heating, | | | | pumps have a plethora of shapes and sizes: |
| ventilating, and air-conditioning, the | | | | from very large to very small, from handling |
| equipment is known as fans or blowers. | | | | gas to handling liquid, from high pressure to |
| | | | low pressure, and from high volume to low |
| The earliest pump was described by Archimedes | | | | volume. |
| in the 3rd century BC and is known as the | | | | |
| Archimedes screw pump. Pumps work by using | | | | Power source |
| mechanical forces to push the material, | | | | |
| either by physically lifting, or by the force | | | | 19th century Dutch diesel pump in Rijswijk, |
| of compression. | | | | Netherlands Domestic Central Heating |
| | | | PumpPumps may be powered by an internal |
| Pumps fall into three categories: positive | | | | combustion engine, electric motor, manually |
| displacement, kinetic (centrifugal), and jet | | | | (as with the hand pump used for pumping |
| (eductor). Their names describe the method | | | | groundwater, called walking beam pump), or by |
| for moving a liquid, such as water. | | | | wind power (common for irrigation). Solar |
| | | | power has been used to power an electric |
| A positive displacement pump causes a fluid | | | | motor, for remote locations |
| to move by trapping a fixed volume of water | | | | |
| and then forcing (displacement) that trapped | | | | Eductor-jet pumps are useful for draining |
| volume into the receiving pipe. Positive | | | | areas which may contain combustible fluids |
| displacement pumps can be further classified | | | | (which could ignite if exposed to the |
| as either rotary-type (for example the rotary | | | | workings of a standard electric or internal |
| vane pump) or reciprocating-type (for example | | | | combustion powered pump) or high levels of |
| the diaphragm pump). | | | | debris (which could damage screws or blades |
| | | | in conventional pump designs). |
| A centrifugal pump causes a fluid to move by | | | | |
| transferring the kinetic (rotational) energy | | | | A source of pressurized fluid (e.g. a |
| from a motor (through an impeller) into water | | | | firehose) is connected to a chamber which is |
| pressure (potential energy). | | | | open on one end, and leads to an exhaust hose |
| | | | on the other end. The pressurized fluid is |
| A eductor-jet pump is special type of pump | | | | forced through nozzles (called eductor jets) |
| without moving parts that uses the kinetic | | | | mounted axially on the inside of the pump |
| energy of a fluid to increase the pressure of | | | | chamber, pointed in the direction of the |
| a second fluid. | | | | exhaust hose. The passage of the pressurized |
| | | | fluid through the chamber and into the |
| Application | | | | exhaust hose creates a suction on the open |
| | | | end of the chamber (Venturi effect), such |
| Pumps are used throughout society for a | | | | that any fluid the pump chamber has been |
| variety of purposes. Early applications | | | | submerged in will be drawn into the chamber |
| includes the use of the windmill or watermill | | | | and thence into the exhaust hose along with |
| to pump water. Today, the pump is used for | | | | the fluid from the eductor jet nozzles. |