Facts about Centrifugal Pumps
For effectively moving liquids through a piping system, centrifugal pumps are generally used. These devices work on the principal of centrifugal force, created by a fast moving impeller in the pump. The rotational movement of the impeller creates movement away from the central axis, which is transferred to the liquid. This force makes the liquid move at a velocity that overcomes the resistance from the friction of pipes, and changes in elevation. However, the force in the liquid decreases as the distance from the impeller increases.
The main components of a pump working on the centrifugal principal are the impeller, shaft, casing, and bearings. The shaft and impeller are the rotating components, the bearings facilitate their easy movement, and the whole contraption is housed in a casing with a cover. The shaft transmits the torque generated by the electric motor during its operation to the impeller, and supports it, along with other parts that rotate. The casing can be circular or volute, and each design has its own unique advantages. A circular casing is ideal for higher capacity and a low head, whereas volute designs are ideal for the shaft to handle the hydraulic pressure in a much better way.
The flow rate achieved by centrifugal pumps mainly depends on the design of the impeller, and its rotational speed. The impellers are designed, so that they give the optimal flow rate, given their diameter and speed. If there is a mismatch between the flow rate and the design of the centrifugal pumps, it will increase the turbulence in the device, and its efficiency will be greatly reduced.
As mentioned earlier, the impeller is the most important part of the pump, and is classified as per its construction, which can be vortex, semi-open and open. Semi-open and open impellers have the least likelihood of clogging, but they require to be adjusted manually for getting the right settings for efficiency, and preventing re-circulation of the liquid internally.
The main operations carried out by the centrifugal pump are to lift and distribute liquids. The device is mainly differentiated by its power to do these operations, and the type of liquids on which it can operate. Models are available for common purposes like pumping water for residential and agricultural uses, as well as models for heavy industrial use for pumping wastes, chemicals, and oils. While selecting a pump you will have to consider the depth at which the liquid is available, and area it has to be circulated or distributed. Accordingly, you will need to choose the horsepower of the motor, and the distribution capacity of the pump, which will satisfy your requirements.
Maintaining centrifugal pumps used for residential and agricultural purposes is not a big task, but make sure you have installed it correctly on a flat, firm and even base. Maintenance mainly involves visual inspection on a regular basis for finding any corrosion, leaks, or breakages. It is always advisable to turn off the motor much before the water runs out, and avoid a dry run. For getting the optimal efficiency, the speed can be adjusted according to output requirements.