GB693871A - Improved air, gas or like fluid compressor - Google Patents

Abstract

693,871. Centrifugal pumps. PIENAAR, T. M. S. July 16, 1951 [July 31, 1950], No. 16854/51. Class 110(i) [Also in Group XXVIII] Means for compressing gas comprises an injector 9 disposed in a closed liquid circuit which entrains gas through a pipe 10 and forces it with the liquid through pipes 7, 6, a circulating pump 2 and a pipe 3 into a single pressure tank 1, where the gas separates from and is compressed in the space above the liquid and forces it through a pipe 8 to the injector. A baffle 21 assists the separation. The injector has an axial convergent-divergent liquid nozzle which is adjustable axially by a rod 26. A foot-valve 25 is fitted to the pipe 10. The gas is delivered through a filter 17 to a valved pipe 19; a safety valve 20 and pressure gauge 18 are fitted. The pump which may be a gear pump or a multi-stage centrifugal pump is driven by an electric motor 15 controlled by a pressure switch 16. Liquid leaking past the pump bearing glands passes through a tube 24 to a container 23 surrounding the gas intake from which it is drawn back into the liquid circuit. Two or more pumps may be used. In another embodiment Fig. 2, a plurality of parallel injectors 7a, which are supplied with liquid from the tank 1 through a pipe 8a, entrain the air through valved inlets 33 and deliver it through a venturi 6, pump 2, and venturi 3a to the tank. Baffles 30 assist gas to separate from the liquid, the latter being circulated by a pump 29 through a cooler 28. When the pressure in the tank exceeds a given value a one-way pressure valve 36 opens communication between the tank 1 and the common delivery manifold 32 of the injectors whereby the back pressure through the latter stops the flow and the pump is caused to run under " no-load conditions; Various types of combining cones are described and where space is limited the combining cones may be in the form of one or more helical convolutions. The air may be introduced into the injector under pressure by means of a supercharger and a cooler and a venturi tube may be disposed between the supercharger and the injector.