An Experimental Study on the Pumping Performance of the Two-Stage Disk-Type Drag Pump

2단 원판형 드래그펌프의 배기 성능에 관한 실험적 연구

In this paper, the pumping performance of the two-stage disk-type drag pump which works in the outlet pressure range from 3 to 0.001 Torr is studied experimentally. The rotational speed of the pump is 24,000rpm, and nitrogen is used as a test gas. The pumping characteristics of various drag pumps are performed. The inlet pressures are measured for various outlet pressures of the test pump. The maximum compression ratios for zero throughput are 1000(two-stage BSC type), 740(helical-type), 90(BSC type) and 85(OSC type), respectively. The ultimate pressure of the two-stage disk-type drag pump is $8.1\times10^6$ Torr.