초록 ▼

A vacuum evacuation system comprising a non-positive displacement type vacuum pump called molecular pump which obtains high pumping speed in a high vacuum range, and an oil-free, positive displacement type vacuum pump called screw vacuum pump. The non-positive displacement type vacuum pump and the p

A vacuum evacuation system comprising a non-positive displacement type vacuum pump called molecular pump which obtains high pumping speed in a high vacuum range, and an oil-free, positive displacement type vacuum pump called screw vacuum pump. The non-positive displacement type vacuum pump and the positive displacement type vacuum pump are connected to each other such that the non-positive displacement type vacuum pump is located on a high vacuum side and the positive displacement type vacuum pump is located on a low pressure or atmospheric side, to thereby prevent oil from being penetrated into a system to be evacuated.

대표청구항 ▼

A vacuum evacuation system comprising: a first vacuum pump having a rotary component which is adapted to rotate at high speeds to produce a linear velocity and against which gas molecules are caused to strike, thus giving momentum of said rotary component in a direction of the linear velocity of the

A vacuum evacuation system comprising: a first vacuum pump having a rotary component which is adapted to rotate at high speeds to produce a linear velocity and against which gas molecules are caused to strike, thus giving momentum of said rotary component in a direction of the linear velocity of the rotary component to produce a gas flow in a given direction; a second vacuum pump having a casing provided with suction and exhaust ports between which a gas flow passage is defined and in which a pair of male and female screw rotors are supported with a minute gap between said screw rotors and said casing, the inner surface of said casing and said pair of male and femal screw rotors defining a working chamber in which said screw rotors rotate with a minute gap maintained therebetween in the absence of sealing, cooling and lubrication liquid, within said working chamber and the gas flow passage thereby producing a differential pressure between the suction and exhaust ports provided in said casing; means connecting said exhaust port of said first vacuum pump to said suction port of said second vacuum pump; and said suction port of said first vacuum pump being disposed on a vacuum side, and said exhaust port of said second vacuum pump being disposed on an atmospheric side.