Pumping oil heated in the pump oil pot to the ebullition state ( about 230 degree centigrade) is caused with evaporation and produced a large amount of evaporated oil liquor speedily and directionally erupted out through nozzles.
As the branch intensity of pressure of the evacuated air nearby the inlet is higher than that of the evaporated oil liquor, so the molecules of the evacuated air are continuously diffused into the evaporated oil liquor with impact on each other caused the molecules of the evacuated air moving rapidly along the direction of movement of the evaporated oil current. The molecules of the evacuated air are bounced back by cylinder wall and re-impact once again on the evaporated oil current. After several impacts, the molecules of the evacuated air are compressed into the lower vacuum end and emptied out by the fore pump after several compression; whereas the evaporated oil current cooled by cylinder wall, flows back to the heater for re-heating. The recurrence takes place again and again.