MULTI-STAGE STEAM-JET VACUUM PUMP Russian patent published in 1996 - IPC

FIELD: vacuum engineering. SUBSTANCE: vapors of working fluid (vacuum oil) formed in evaporator 6 after switching on heater 7 interact with gas being evacuated while passing through vapor line 4 and escaping from umbrella-shaped nozzles 5, thus imparting additional velocity in direction of evacuation to molecules of this gas. Working fluid condenses on cooled parts of housing 1 and returns to evaporator 6 over circular insert 8 fitted in area of first stage and cylindrical shell 9 between which heat-insulating gasket 10 is laid. As a result, working fluid is degassed. After last stage, gas is evacuated by means of roughing-down pump and vapors of working fluid are condensed in branch pipe 2 wherefrom condensate enters circular oil receiver 11 and then flows to taper bell mouth 13 through chute 12. Bell mouth 13 provides for even distribution of oil over outer surface of shell 9, thus decreasing its temperature at excessive heating from lower stages of pump. Provision is made for self-control of evacuation procedure due to which effective degassing of oil is ensured and characteristics of steam-jet pump are improved. EFFECT: increased output, reduction of limiting residual pressure and reduction of return flow of working fluid vapors. 1 dwg