STEAM-JET VACUUM PUMP Russian patent published in 1997 - IPC

FIELD: vacuum engineering. SUBSTANCE: pump has cylindrical housing 1 and steam duct 2 mounted coaxially with respect to the housing. The steam duct has active supersonic nozzle 3 outer wall 4 of which is converging in the direction of the nozzle outlet. Cooled shield 5 is mounted concentrically and with a spaced relation to the nozzle. Above the cooled shield is hot shield 6 to exclude the molecular flow to the housing from the slot between the wall of the nozzle and screen 5 and from the surface of shield 5 as well. EFFECT: enhanced efficiency. 1 dwg