The majority of industrial pump systems make use of a centrifugal pump. If you have ever contacted a pump supplier, then you would have probably heard the term, “centrifugal pump.” Ever wondered what exactly is the centrifugal pump and why is it so widely used in all applications?
Here, in this post, we answer all your questions about centrifugal pumps – the parts, working principles, advantages and more.
What is a Centrifugal Pump?
Any pump - be it centrifugal, submersible or any other type - is used to transmit a liquid from a region of low pressure to a region of high pressure. A centrifugal pump is a hydraulic machine that converts mechanical energy into hydraulic energy. It does so with the help of centrifugal force acting on the displaced fluid.
The Different Parts of a Centrifugal Pump:
The main parts of a centrifugal pump are:
Shaft – This is the central part of the pump. It rotates the impeller connected to it. The shaft is attached to the prime mover to generate power. The shaft is fitted using a ball bearing.
Impeller – It consists of several curved vanes. It is attached to the shaft of an electric motor. The impeller makes up the rotating part of the centrifugal pump. Generally, the impeller is enclosed within a watertight casing.
Casing – This is a water-proof and air-tight passage outside the impeller. It is designed to convert the kinetic energy of the discharged water into pressure. The purpose of the casing is to act as protection.
Types of Casings Used in Centrifugal Pumps:
Also known as Spiral Casing, this surrounds the impeller. This casing is used to decrease the velocity of water, thereby increasing the water pressure.
This is a circular chamber between the impeller and the volute casing. The fluid first passes through the vortex casing and then through the volute casing. This helps in better conversion of the velocity energy into water pressure.
Casing with Guide Blades
These are casing blades that directly surround the impeller.
How does a Centrifugal Pump Work?
To better understand and troubleshoot your industrial pumps, you need to have a clear idea of the operating principles of centrifugal pumps. The basic principle of operation of centrifugal pumps is – force vortex flow.
This means, when a body of liquid is acted upon by an external torque, it increases the pressure head of the rotating liquid. This increase in pressure is directly proportional to the velocity of the liquid. Thus, the rise in pressure is higher at the impeller outlet, causing the liquid to discharge at high pressure at the outlet.
Because of this high-pressure head, the displaced liquid is lifted to high heights in a centrifugal pump system.
What is Centrifugal Pump Priming and why is it needed?
Priming refers to the principle of filling the suction pipe, casing and parts of the delivery valve with liquid from an external source. Priming is done to raise the liquid in the pump, before starting the operation.
In a centrifugal pump, the pressure in the impeller is directly proportional to the density of the liquid in the impeller. If the impeller is running when filled with air, the pressure generated is negligible, which is not suitable for your operation. To avoid this scenario, you need to ensure that the pump is primed before beginning operation.
Differences between a Centrifugal Pump and a Reciprocating Pump
Reasons to Use Centrifugal Pumps
- The biggest benefit of using centrifugal pumps is that they are simple machines.
- They work well for applications that require large discharge and small heads.
- It doesn’t have any moving parts or valves. Hence maintenance is easy.
- Centrifugal pumps can run at high speeds with minimal maintenance.
- It produces a steady and consistent output.
- They are highly flexible, and you can reposition them easily if needed.
That’s it. Now, you know all about centrifugal pumps. If you have any further queries or doubts or need help choosing the right centrifugal pumps for your application, don’t hesitate to get in touch with us. For further reading, check out our checklist for overhauling your old centrifugal pumps. Reach out to Sintech, India’s leading industrial centrifugal pump suppliers for all your pump queries.