Centrifugal pumps are machines that move fluid by transferring rotational energy from one or more rotors (also known as impellers). The fluid enters the impeller along its axis. It is then propelled by the centrifugal force toward the circumference of the impeller and it gets out through the vane tips of the rotor. Pumps can be used in so many industries and technologies, one of those being Immunoassay Development
The rotation of the impeller increases the pressure and the velocity of the fluid while also directing it towards the outlet of the centrifugal pump. The casing of the device is designed to direct the fluid through the inlet into the impeller and then slow it down and control it before it exits through the pump’s outlet.
What Is The Working Principle Of A Centrifugal Pump?
The impeller is the most important element of a centrifugal pump. This device features several curved vanes mounted between two discs. This configuration is what we know as an enclosed impeller. In case of fluids with entrained particles of solid matters, open or semi-open impellers work best.
The pump casing can have either a volute design or a diffuser design. Both designs are meant to move the fluid and discharge it at a controlled pressure.
Centrifugal Volute Casing Pumps
Both volute and diffuser casing designs share the same working principle. The fluid pressure increases as a result of expelling the fluid through the stationary vanes around the impeller. Different diffuser designs suit different applications, the main goal is to increase the efficiency of the pump. Volute cases are the ideal choice for applications involving high viscosity fluids or entrained solid particles. In such situations, added constrictions are welcome. hence the need for diffuser vanes. The asymmetrical volute design may cause additional wear on the driveshaft and on the impeller.
Centrifugal Diffuser Casing Pumps
Basic Features Of A Centrifugal Pump
There are two main types of pumps: positive displacement and centrifugal pumps. Centrifugal pumps are the preferred choice in situations that call for higher flows and in case of lower viscosity fluids. Some chemical facilities use almost exclusively centrifugal pumps. Nevertheless, there are applications that require positive displacement pumps.
Are There Any Limitations To Centrifugal Pumps?
The main requirement for a centrifugal pump to operate efficiently is the high-speed constant rotation of the impellers. The higher the viscosity of the fluid, the less efficient centrifugal pumps are, as they require greater resistance and higher pressure to maintain the desired flow rate. This is the main reason why centrifugal pumps are usually best for low pressure, high capacity pumping applications, and for low viscosity fluids.
Mud, slurries, or high viscosity oils cause premature wear and overheating, making centrifugal pumps prematurely collapse. In such situations, positive displacement pumps are much better, because they operate at lower speeds, and are subject to less wear and tear.
Fluids that are sensitive to shearing can be affected by the high speed of centrifugal pumps. This is why positive displacement pumps are better, as they prevent the separation of emulsions or biological fluids.