The Multijector Principle
Advantages of Multijectors
Multijector Applications
Our Multijector Designs
Small: K-Series
Midsize: M-Series
Big: G-Series
Stainless: RVA-Series

Varijector Series

Special Customized
Vacuum Pumps and
Vacuum Solutions

MULTIJECTOR® Vacuum Pumps: See how they work.

The classical Ejector (Venturi)…
Compressed air driven vacuum pumps have a lot of advantages over alternative pump designs such as small size, low weight, simple construction, as well as wear and virtually maintenance free operation. The control system is operated entirely by pneumatics off the compressed air supply, which enables the pump to be used safely in hazardous areas. The pumps are quiet in operation and do not emit either heat or dust or cause vibration.

But how to make a Venturi more efficient and economic?
A look at the diagram below indicates how the MULTIJECTOR works: A classical Ejector consists of a primary nozzle (injector), a mixing chamber and a diffuser. Compressed air is supplied through the primary nozzle, expands quickly, entrains air in the mixing chamber and leaves the pump into the surroundings through a diffuser.

... the multiple stage MULTIJECTOR®
Volkmann Multijectors use multiple ejector stages, which save compressed air and reduce running costs. When additional nozzles are built behind the diffuser, the air ejecting from the first stage, (which consists of compressed air mixed with the suction air induced by the venturi effect), serves the following stage as a „free“ propulsion jet, which does likewise for subsequent stages. These additional stages do not reach the high vacuum of the first stage, but they vastly enlarge the effective suction capacity, at reduced vacuum, for no additional compressed air usage.

However, the vacuum pump can still achieve the same high vacuum as the first Ejector stage because the following stages are actually separated from the common vacuum chamber by flap valves, which close off if the suction requirement increases. This particular nozzle geometry and flow guidance makes it possible for the MULTIJECTORS to be very efficient, for minimum compressed air usage.

Multijectors save compressed air and reduce operation expenses.