Is liquid ring vacuum pump a centrifugal pump?

Is liquid ring vacuum pump a centrifugal pump? This question has been asked recently. Vacuum pump manufacturers will introduce to you whether there is a subordinate relationship between the two.

First of all, it should be clear that liquid ring vacuum pump does not belong to centrifugal pump. We can make a clear distinction between them from the practical occasions. Although both of them have the use of centrifugal force. But liquid ring vacuum pump is used for vacuumizing gas, which is a kind of positive displacement gas equipment. The centrifugal pump is used for conveying liquid, which belongs to velocity type fluid equipment. One is a vacuum pump, the other is a water pump.

Structure difference between centrifugal pump and liquid ring vacuum pump

The application of centrifugal force in liquid ring vacuum pump is mainly that the liquid is thrown around the impeller in the process of rotation to form a certain thickness of ring for sealing. The impeller is installed eccentrically, so a relatively closed crescent shaped space will be formed between the liquid ring and the cavity. At the same time, the closed ring combines with the impeller, and separates some spaces into independent suction and exhaust spaces. In the process of rotation, through the volume change of the closed space, the process of suction, compression and exhaust is realized, and the gas extraction of the vacuum chamber is completed. In the early days, liquid ring vacuum pump was also used for self-priming pump.

And the centrifugal pump is a pump that simply relies on the centrifugal force generated when the impeller rotates to deliver the liquid. The concentric impeller rotates at a high speed in the cavity filled with water, which throws out the water and forms a vacuum negative pressure in the pump cavity at the same time. The new water is sucked in, so it circulates to realize liquid transmission.

Is liquid ring vacuum pump a centrifugal pump?