4.8 Side channel high vacuum pumps
4.8.1 Design / Operating principle
The side channel high vacuum pump is a vacuum pump that works from atmospheric pressure to the high vacuum range. This pump is a combination of a side channel pump (pressure range 1,000 to 5 hPa, laminar flow) and Holweck stages (pressure range 5 to 10-5 hPa, transitional and molecular flow).The pumping system in a side channel vacuum pump (Figure 4.20) consists of a rotor disk (1) having blades (2) that are arranged on the outer perimeter and a ring-shaped working chamber, the side channel (3). The side channel is narrowed to the disk profile at one point by a breaker (4). The pumping effect occurs through a helical flow from the inlet to the outlet that is produced by the blades of the rotating rotor. This results in a pressure differential between inlet (5) and outlet (6). Lower ultimate pressures can be attained by connecting multiple pumping stages in series.