Rotary Vane Vacuum Pumps

Single-stage rotary vane vacuum pumps from Pfeiffer are the ideal solution for the rough vacuum range. They are known for their quiet operation and compact design, making them a perfect choice for laboratory environments or mass spectrometry.

These vacuum pumps feature a hermetically sealed design, made possible by encapsulating the motor directly within the pump housing and eliminating conventional shaft seals. Since these seals are components typically prone to wear and leakage, their removal increases overall reliability, extends service life, and reduces maintenance requirements.

Benefits

Two-stage rotary vane pumps from Pfeiffer are engineered for high performance in various industrial and scientific applications in the medium vacuum range such as coating or freeze-drying. They deliver high pumping speeds and are able to handle a wide range of gas types. Many models are also available with an optional magnetic coupling. This innovative design magnetically connects the motor to the pump. As a result, the rotor inside the vacuum pump is driven without the usual shaft seals, preventing leakage and contamination.

Benefits

Rotary vane vacuum pumps are positive displacement pumps that utilize a rotor with vanes to generate vacuum. These rotating vanes form chambers between themselves and the pump housing in which they trap the pumped medium, effectively evacuating a sealed environment. Rotary vane vacuum pumps are known for their durability and efficient operation. Their reliable performance makes them a preferred choice in various industrial or scientific applications, including coating or freeze-drying.

In a rotary vane vacuum pump, a rotor with several vanes is mounted eccentrically inside a cylindrical housing. As the rotor turns within the housing, the vanes slide out of the rotor due to centrifugal force, creating a series of expanding and contracting chambers with the housing. The process can be broken down into three main steps:

Inlet:

Most models of rotary vane vacuum pumps from Pfeiffer have an integrated gas-ballast valve to improve water vapor compatibility in processes like freeze-drying. This prevents corrosion inside the pumps and elongates their service life. When the gas-ballast valve is opened, non-condensable gas flows into the vacuum pump. It mixes with the present vapor before it can condense and is expelled through the exhaust.

In processes with high thermal load such as heat treatment, a flushing gas like nitrogen can be introduced. This inert gas forms a layer above the operating fluid, protecting it from potential contamination through the process gas.

Special oils are essential for the operation of rotary vane vacuum pumps. They are used to seal the clearance between the vanes and the housing, enabling lower ultimate pressures. Additionally, the oil ensures continuous lubrication, resulting in reduced wear and a longer service life. The selection of the appropriate operating fluid allows the vacuum pumps to be better adapted to specific processes. For example, Pfeiffer offers special oils for corrosive processes. These synthetic oils protect the vacuum pump against contamination by corrosive media such as solvent vapors and prevent oxidation and rapid aging of the oil. All Pfeiffer operating fluids are specially designed for each vacuum pump model, with particular emphasis on achieving optimal performance in combination with a long service life.

The main difference between single-stage and two-stage rotary vane vacuum pumps lies in their compression processes and the resulting vacuum levels. A single-stage rotary vane vacuum pump compresses the pumped medium once. This generates medium vacuum levels, which are suitable for applications such as packaging foodstuffs. In contrast, a two-stage rotary vane vacuum pump compresses the pumped medium twice: first to a rough vacuum level, then the process is repeated a second time. This allows the vacuum pump to generate higher vacuum levels in the medium range, making it ideal for applications such as sterilization.