MVD Series
The MVD series is the new standard for the research and development industry. Models in the Marpa Vacuum MVD Series are two-stage, air-cooled and direct-driven and operate with recirculating oil. Their compact design is dependable, durable and easy to maintain and operate. Thanks to their air-cooling system, they are easy to install and do not require water for cooling. The pumps are direct driven and, therefore, do not need belts, They are capable of reaching a final vacuum of 10⁴ mbar and come equipped with a standard gas-ballast valve, which allows for high volumes of vapour to be extracted. In addition, they are equipped with a non-return valve on the suction flange, preventing the pumped medium from flowing back into the vacuum process when the vacuum pump is switched off.
Operating principle
Rotary vane pumps in an oil bath operate according to the rotary vane principle.
They consist of a cylindrical housing (1) with an eccentrically positioned rotor (2) and several free-moving vanes (4). The vanes are located in the rotor slots (3), and as the rotor rotates, the centrifugal force pushes them against the cylindrical wall while creating a chamber between the rotor and the cylinder (7). The volume of the chamber changes as the rotor rotates. From the inlet (5), the chamber volume enlarges and then decreases towards the outlet (6). When air enters through the inlet (5) and the chamber enlarges (7), the vanes create a vacuum. When air is pushed through the chamber and compressed, pressure is produced at the outlet (6). As two-stage pumps, the air flows from the exhaust outlet of the first housing to the suction port of the second housing. The process that takes place in the second housing is the same as in the first housing and produces a higher final vacuum level.
