Four Types of Vacuum Pumps

Vacuum pumps are mechanical pieces of equipment that allow the removal of air and gas molecules from a sealed area to create an ideal vacuum environment. In general, it is meant to clean and seal. These pumps are available in wet or dry variants depending on the media being pumped through them.

A wide variety of industries and applications use vacuum pumps to eliminate air and gas molecules from a process. These include the food and beverage industry, medical plastics, pulp and paper, woodworking, and the semiconductor and electronics industry. This article explores the main kinds of vacuum pumps designed specifically for each respective application and used in industrial laboratories for freeze-drying, evaporation, composites, vacuum purging, distillation, and material testing. 

Rotary Vane Pumps

Rotary vane pumps have lower upfront costs. These compact pumps are ideal for those who want the right balance between form and function. These pumps require oil for operation to guarantee a tight seal, well-lubricated moving parts, and great heat dissipation to cool the pump. Because these pumps do not have internal metal-on-metal contact, they tend to experience less wear and extended peak performance. Visit to check out your options. 

When using an oiled pump, a cold trap should be used as the oil will re-condense vapors and cause the performance of the pump to drop or the pump to seize up. It is important to replace the oil after every twelve hours of use or when it begins to discolour if a cold trap is not used. In addition, as rotary vane pumps reach deep ultimate vacuum levels and have high displacement capacity, they are ideal for freeze-drying applications.

Liquid Ring Pump

This pump compresses gas by rotating a vaned impeller situated eccentrically within the pump housing. When liquid is fed into the pump by centrifugal acceleration, it forms a moving cylindrical ring against the inside of the casing. The ring creates a series of seals in the space between the impeller vanes that form compression chambers. 

Diaphragm Pump

This dry pump operates through a pulsing motion that opens and closes diaphragms to shift air. It is mainly designed for applications such as rotary evaporation, continuous operation, and dealing with volatile compounds. 

Scroll Pumps

These pumps use two spiral scrolls for compressing air and vapors and pushing them out of the exhaust. Scrolls pumps don’t require the use of oil and process water vapors better than most other pumps. Because they are best used in aqueous and solvent samples, they are a great candidate for freeze-drying.