| 摘要 |
<p>PCT No. PCT/SE89/00040 Sec. 371 Date Aug. 6, 1990 Sec. 102(e) Date Aug. 6, 1990 PCT Filed Feb. 3, 1989 PCT Pub. No. WO89/07203 PCT Pub. Date Aug. 10, 1989.A liquid driven pump has a driving-liquid accelerating nozzle which opens into a pump chamber having an outlet part positioned coaxially with the nozzle. Opening into the pump chamber is an evacuation line which is intended for connection to a space to be evacuated. The outlet part of the pump chamber discharges into a coaxial drainage chamber and has an abrupt increase in cross sectional area in relation to the outlet part. The drainage chamber has downstream net-like elements which are passed through by the liquid. The relationship between the smallest cross sectional areas of the nozzle and the outlet part respectively and the distance between the nozzle orifice and the drainage chamber are such that essentially the whole of the diffusion process takes place through the agency of the net-like elements. The smallest cross sectional area of the outlet part is from 1.4 to 4.8 times larger than the nozzle orifice area, and the drainage orifice is substantially circular in shape having an area which exceeds the total open mesh area of the net-like elements and which is from 15 to 45 times larger than the area of the nozzle orifice.</p> |
