Liquid Ring Vacuum Pumps

The durability and versatility of a liquid-ring vacuum pump makes it the ideal choice for many applications in a variety of industries such as petrochemical, power, sea water deaeration, food production and pharmaceutical.  Not only is it economical in its pricing when compared to other types of vacuum pumps, but its corrosion resistant properties make it rugged and ensures a lifespan from between ten to fifteen years, or even more in some cases.

Benefits of a Liquid-Ring Vacuum Pump

There are many benefits to selecting a liquid-ring vacuum pump for your business. As mentioned, they are the most rugged and reasonably priced when compared to other systems available on the market. Here are a few more benefits to take into consideration:

  • Low maintenance requirements
  • Liquid-ring vacuum pumps are capable of moving large amounts of soft-solids and liquid without incurring mechanical damage
  • These particular pumps are fitted in various metals, such as bronze, iron and stainless steel
  • These particular pumps are ISO9001 manufactured

How does it work?

A liquid-ring vacuum pump has an impeller with blades that are situated on a shaft that are off-set from the centre, and is located in a cylindrical body.  The blades are situated closer to the top wall of the pump than to the side and bottom walls of the cylinder. The impeller sits between two plates with holes cut into them which act as the inlet and outlet ports.  

When in use, the pump uses liquid, which is also called a sealant which is used to create a vacuum. The pump is partially filled with the liquid sealant before it is started.  Depending on the application, the liquid used can be water, a solvent or an oil. Once the pump is started, the impeller pushes the liquid sealant against the outside walls of the cylinder by centrifugal force.

Due to the fact that the impeller is offset, some of the blades will be fully immersed in the liquid and other parts of the impeller will not necessarily be submerged at all.  

The void that contains no liquid is called the impeller cell and this is where the suction of the pump occurs, drawing in air, gases or vapours through the inlet port and passes these out through the outlet port into the atmosphere. This process manages the pressure within the system.

Single-Stage vs Two-Stage Liquid-Ring Vacuum Pumps

In a single-stage pump, there is suction and compression in one revolution of the pump.  A two-stage pump comprises of two of these operations simultaneously, resulting in better efficiency at higher vacuum levels than a single stage pump.  These are designed to operate at levels higher than 20”HgV.