A Vacuum pump is essentially a pump that removes gases & vapours from a sealed container. Removal of the gases creates a partial vacuum in the container, or correctly, a pressure lower than atmospheric pressure.
Most Vacuum pump types are of a positive displacement design which can typically achieve quite high vacuum pressures but at low volumes. These include; Rotary Vane pumps, Diaphragm Pumps, Piston Pumps & Lobe Pumps.
For higher volume gas removal, higher speed rotodynamic pumps are required such as Liquid Ring Pumps, Screw Pumps & Scroll Pumps.
Most of these pumps can also be used for positive pressures & ‘Blow’ the gases to a pressurised state.
LRV (Liquid Ring Vacuum) Pump
Liquid Ring Vacuum pumps are ideal where large volume continuous gas removal is required without the need for high vacuum pressures such as process works & evisceration systems.
Will also tolerate some moisture carryover but require a separate liquid & cooling source to operate.
Lobe Vac Pump
Lobe vacuum pumps require no cooling liquid & as such run hot. The main advantage is their ability to handle corrosive vapours with standard inexpensive iron construction since the elevated temperatures removes the moisture associated with corrosion.
Rotary Screw Vacuum Pump
Rotary screw vacuum pumps can at high speeds & are capable of reaching extremely high vacuum pressures.
They run extremely hot limiting usage to gases which are not temperature sensitive or flammable & they are generally costly to repair
Rotary Vane or Sliding Vane Pump
Rotary Vane or Sliding Vane Pumps use a rotor rotating offset inside a circular chamber. The vanes slide in & out of the rotor and seal on all edges creating rotating cavities that compress at the discharge point expelling any gasses & liquids present. They are available in both oil lubricated or dry running, can operate at low speed, handle flammable liquids & gasses & can pull a reasonably high & controlled vacuum.
Common brands serviced include;
Busch, Becker, Emtivac, Tuthill, Robuschi, Nash, IBS, Pompe Travaini, Sihi, Suoto, Roots, Rothenberger, Flowtech, Edwards and PDA.