POSITIVE DISPLACEMENT DRY VACUUM PUMP

摘要

A decompression chamber (3) of a positive displacement dry vacuum pump (1) can be communicated with a site (16a) of the suction side of a third-stage pump chamber (16) of a pump body (2) through a second hose (5) and a second vacuum valve (7), and can be communicated with a site (18b) of the exhaust side of a final-stage pump chamber (18) through a first hose (4) and a first vacuum valve (6). During the drive, the second vacuum valve (7) is opened only for a predetermined time period to evacuate the decompression chamber (3), and the first vacuum valve (6) is then opened to evacuate the pump body (2) side using the decompression of the decompression chamber (3), causing the drive load to be reduced. Pump power consumption can be reduced without the need for an auxiliary pump by repeating the evacuation of the decompression chamber (3), and the evacuation of the pump body (2) side using the decompression chamber (3).