Understanding the Working of Liquid Ring Vacuum Pumps

Liquid ring vacuum pumps are devices used for producing a vacuum in industrial environments. These types of pumps consist of an impeller that is located at the center with a cylindrical body known as the vacuum pump housing. A liquid seal is there in the vacuum pump to create the vacuum. The common sealant used in industrial water pumps is water and the other liquid sealants popularly used as oil and also a mixture of water and methanol.

Before operating a vacuum pump, the sealant fills at least one-fourth of cylinder volume. In general vacuum pumps, there is an impeller which is located between the port plates. These port plates function as suction and discharge of the vacuum pump with shaped holes on them, which are called ports.

Functioning of a vacuum pump

While switching on a vacuum pump, the impeller starts rotating, and the liquid tends to move outside due to centrifugal force. This creates a void space without liquid and the liquid forms a ring shape. The part between the liquid and the impeller vane is known as the impeller cell.  The impeller rotation is in a clockwise direction.

At this point, the top of the impeller cell gets filled with the sealant. With the impeller rotating, the liquid level recedes from the center of the impeller and creates a vacuum space in the cell. With this action, air or vapor is taken from the vessel to be maintained at vacuum through an inlet at the sides of the impeller. Once the impeller cell passes inlet port to move towards the discharge port, the liquid is again forced back to the center hub creating the compression phase.

Then as impeller cell nearing to discharge port, compression reaches its highest threshold and the gas along with a little liquid sealant exhaust through the discharge port. The liquid sealant is in fact very turbulent, and this is the reason why a few amounts of the sealant also getting discharged with gases. Again, the same cycle gets repeated.

The pump system

The Vooner liquid ring vacuum pump system is actually the complete arrangement including the pump, separator vessel, connection pipes, and other fittings. There are three types of pump systems as:

• Once-through pump system
• The partial recirculation pump system
• The total recirculation pump system

Liquid ring vacuum pump function

In liquid ring vacuum pumps, there is no recirculation taking place. So, the contamination of the sealing liquid is not a concern in such systems. The primary advantages of liquid ring vacuum pump systems are:

• Simple to install and use
• Low installation cost
• Ideal for less-critical services

Disadvantages are:

• Consume a high volume of sealing liquid
• Operational cost, in light of the above, maybe a bit high.

When it comes to choosing a liquid ring vacuum pump for industrial use, there are plenty of manufacturers and a wide range of models available in the market. However, as such mechanical equipment plays a crucial role in your industrial productivity and quality, it is important to choose the best system for your purpose.