Pump – a device used to move gases, liquids or slurries. A pump moves liquids or gases from lower pressure to higher pressure, and overcomes this difference in pressure by adding energy to the system (such as a water system). A gas pump is generally called a compressor, except in very low pressure-rise applications, such as in heating, ventilating, and air-conditioning, where the operative equipment consists of fans or blowers.
Pumps work by using mechanical forces to push the material, either by physically lifting, or by the force of compression.
What’s the problem?
- Ask – rather than carrying buckets of water from a river to a house on a hill near by, it would be easier to have a mechanical device to move the water. How can water flow uphill? What does the mechanical device need to do to transport water?
- Imagine – By forcing the water through a pipe, it can be moved continuously from one place to another. With enough force the water can be moved uphill. How can force be applied to the water?
- Plan, Create – In the earliest water pumps, the force or power was provided by the flow of the river turning a water wheel, which lifted the water to level above the river. How did the pump ensure that the water didn’t flow back down?
- Improve – Pumps became more complicated with values that closed off the flow of water to prevent it flowing down, while the pump relocated the lift portion for the next “load” of water.
- engine, pump, water-driven
Challenges for you to work on…
- find early examples of functional pumping devices
- Denis Papin constructed a model of an engine for raising water from a river by means of pumps worked by a water wheel driven by the current,