Broader Categories
There are two broader categories, which provide the basis of classification. First is the positive displacement type. Here, the fluid moves from a section of reduced volume to the increased one. This ensures a regular flow in spite of the changes in pressure. However it contains a release valve to prevent severe fluctuation. The other is the dynamic one. Here, the movement of fluid relies upon its own momentum. The Dynamic water pumps can be divided into 2 parts depending upon the motion of the fluid.
Rotary Motion- Centrifugal Pump
This type of water pumps has a component called Impeller, which drives the fluid and converts its energy into pressure. The water is stored in a Pump Casing. It is essential to avoid leakage of fluid by using labyrinth seals, mechanical seals or gasket. The motor provides current for the pump to run. It is necessary to use oil to avoid friction and maintain the flow. The actual movement is caused due to the rotation of the fluid therein.
Linear Motion-Jet Pump
The jet water pumps are the most common example of the linear motion of the fluid. These do not possess any moving parts that drive the water inside it. These are also called Eductors or air ejectors. Such pumps works on the principle of creating low pressure. The movement completely relies on the changes in the fluid. But there efficiency decreases with increase in pressure. Hence, instead of pumping water they are commonly used to remove water. These make use of nozzles and a freeder stream. Although care must be given to ignite it properly otherwise it would star pumping water instead of drawing it.
In a nutshell, one can say that Water pumps work on the principle of compression or physical lifting both for pumping water and removing it. They are used in swimming pools for sanitizing the water. These also help in retaining the chlorine composition in the beach water by sucking the water vapor using these pumps.
