A liquid ring pump is much alike rotary vanes pump that uses rotational motion for gas compression and several other applications. These pumps are very popular, as they are functional and act perfectly for all kind of pumping needs. This type of pump comes with a moving rotor that is responsible for creating centrifugal rotation used to churn a liquid better known as sealant. It is supplied to the pump, as a result of the churning process, a liquid ring in continuous rotation forms that limits the frictional forces acting on the machine and the compression chamber of the pump is sealed using this moving liquid wheel.
How the liquid ring pump is designed to perform?
In order to understand the working principle of this specific type of vacuum pump you must understand its design properly. The main functional part of this type of pump is an impeller that remains attached to the blades. This entire configuration remains in contact with a central hub. The impeller is smartly designed to fit in between two specific port plates that have unique holes called ports attached to the port plates.
The sealant liquid is an integral part of a liquid ring pump. The vacuum is generated through the sealant liquid. Water is most widely used as a sealant liquid. Else, you can use any solvent liquid you may find suitable including a wide variety of oils. Before the pump is brought back to the action site, it requires some rest or period of no action. During this period, the machine should be filled with the sealant as per the requirement. Some, not all blades of the impeller should be submerged in the sealant. This is important for generation of the liquid ring.
As the liquid ring pump starts working the impeller blades propel or start rotating in order to generate centrifugal force. The centrifugal force pushes the sealant liquid towards the outside body walls of the pump where it forms a rotating ring like structure. This pump works as a piston to generate vacuum. It also creates a chamber like space that is responsible for the suction action of the pump. It sucks in gases through the inlet ports of the impeller and directs them towards the outlet ports. The overall resultant action performs the gas compression function.
Different types of liquid ring pumps
There are mainly two specific types of a liquid ring pump-
- The single stage liquid ring pumps or the conventional type of liquid ring pumps where only a single liquid ring acts for gas compression.
- The two-stage or multi-stage liquid ring pumps where more than one liquid ring unit is used. These are far better at vacuum generation and are more efficient, as well.
Uses of liquid ring pumps in various industries
These pumps are found to be exceptionally useful in the following industries:
- In power generation industry where gas condensation is highly required.
- For de-aeration of seawater.
- In pharmaceutical and petrochemical industries.
- Where remediation of ground water is required.
- In food processing and packaging industry.
Pros and cons of using liquid ring pumps
Pros: Liquid ring pumps are compact and come with simplistic designs. Additional gear boxes are not required. Do not induce much temperature fluctuations while working. Neat and small design takes a small area for installation. Friction is greatly reduced. Hence, it works for a longer duration of time. Low in maintenance and operating it is pretty easy too.
Cons: There are some cons of using a liquid ring pump too like it is not very high in efficiency and sometimes the vacuum degree is low too.