Background and Identification
Hand pumps are manually operated pumps that use human power and mechanical advantage to move fluids (liquids or gasses) from one place to another. Hand pumps are used widely around the world for industrial, marine, irrigation, and leisure activities. Hand pumps generally operate on a piston, diaphragm, or rotary vane principle with a check valve on the exit and entry ports operating in opposing directions. Most hand pumps use positive displacement to move fluids and are either piston pumps or plunger pumps.
Hand pumps are commonly used in developing countries for community- and self-supply of water and can be installed on hand-dug wells or boreholes. Around 2000 B.C., Egyptians began using a long suspended rod with a bucket on one end and a weight at the other to raise water. It was not until around 200 B.C. that Ctesibius, a Greek inventor and mathematician, invented the water organ, an air pump with valves on the bottom, a tank of water in between, and a row of pipes on top. This pump was the principal design for the modern reciprocating pump. Archimedes designed the Archimedean screw pump around the same time, and it is still used for pumping liquids and granulated solids in both developing and industrial countries for irrigating agricultural fields without electrical pumps.
Air pumps are pumps for pushing air and include bicycle pumps, aquarium aeration pumps, gas compressors, air horns, pipe organs, vacuum cleaners, and bellows. All air pumps include a moving part such as a vane, piston, impeller, or diaphragm that drives the flow of air. When air is moved, an area of low pressure is formed, which is then filled with more air. Pumps and compressors use similar mechanisms and perform the same actions in different fluids. For instance, compressors operate on compressible fluids (typically gases) while pumps generally operate on incompressible fluids, such as liquids. Air pumps, however, are designed to operate in the air.