Liquid ring vacuum pumps
and compressors

A liquid ring vacuum pump is a positive displacement pump that uses a liquid as a sealant. The liquid, also referred to as operating fluid, is usually water. Other fluids can also be used if required to suit the process conditions.

The housing is partially filled with operating fluid, and the blades of an eccentrically mounted impeller dip into it. As the impeller rotates, a liquid ring is created due to the centrifugal force. Chambers are formed between the impeller and the liquid ring, and the rotation of the impeller alters their volume. The pumped medium is transported in these chambers, where it is compressed and expelled via the outlet. Liquid ring vacuum pumps are available in single- and two-stage versions. Compression is carried out once in single-stage versions. Two-stage versions compress the pumped medium twice to achieve higher vacuum levels.

The operating fluid creates a barrier that prevents contamination from entering the pump. Liquid ring vacuum pumps are often used in processes where a liquid is already present that can be used as the operating fluid. They are particularly well suited for industries such as hospitals and healthcare facilities, vapor recovery, and biogas handling.

Liquid ring technology is synonymous with robust construction and a well-proven, highly reliable design.

An eccentrically mounted impeller rotates in a housing partially filled with operating fluid. The impeller blades dip into the fluid, and the centrifugal force exerted by their rotation forms a so-called liquid ring within the housing.

The pumped medium is transported in the spaces between the blades and the liquid ring. The eccentric rotation of the impeller alters the volume of these spaces. Thereby, the gas is drawn in, compressed and expelled.

Vacuum generation in liquid ring vacuum pumps explained in three steps

Compressors produce overpressure while vacuum pumps produce vacuum.

Basically, a liquid ring compressor is built the same way as a liquid ring vacuum pump, only the inlet and outlet are connected the other way around.

Liquid ring vacuum pumps and compressors from Busch are robust, reliable, and cost-efficient. They have several benefits:

There is no difference. These are just two different names used to refer to the same technology. However, the name liquid ring indicates that other liquids besides water can be used as an operating fluid.

Several factors should be considered when selecting the appropriate liquid ring vacuum pump type.
To find out which vacuum pump fits your needs best, get in touch with our Busch experts.

Busch has over 40 years of experience in manufacturing liquid ring pumps.

Our DOLPHIN LA/LB and LG/LR ranges come in a large variety of housing metals.