The diffusion vacuum pump construction consists of an oil boiler connected to a central multi-stage jet assembly.
The heated oil is ejected from the jet assembly at supersonic speeds and the process gas molecules are entrained in the oil jet flow and transferred through the pump body by the heavier oil molecules' momentum. This process moves the gas molecules from the low pressure inlet flange to the foreline vacuum port of the diffusion pump, where the oil is condensed and returned to the boiler and the process gas molecules are removed by the backing pump.
The diffusion vacuum pumps' innovative multi-stage jet design results in the utmost stability of the pumping operation. The design is especially suited for high transient pressures typically found when pumping down a chamber without the associated risk of oil back streaming.
All diffusion vacuum pumps benefit from a robust long life heater design, which ensures stable and reliable performance under widely varying operating conditions.
Dry Vacuum Technology for Chemical and Pharmaceutical Processes