GB806219A - Multi-stage radial flow compressor and method of operating same - Google Patents

Abstract

806,219. Centrifugal compressors. MASCHINENFABRIK OERLIKON. Oct. 25, 1956 [Oct. 29, 1955], No. 32609/56. Class 110 (1). In a multi-stage radial-flow compressor, an intermediate outlet is provided before at least one end stage for use during partial pressure operation, the end stage or stages then conveying only sufficient medium to keep them cool, and surging in these stages being prevented by narrowing the inlet to each impeller by means of a slide valve. During normal operation, the four stages 2 are connected in series with the two end stages 3 by way of a valve 14 and a conduit 15 to deliver through an outlet 9 and a valve 21 to a delivery line 10. During partial pressure operation, valves 14 and 21 are closed and the four stages 4 deliver through an intermediate outlet 13, conduit 11 and a valve 12 to the delivery line 10. Valves 18 and 19 are opened so that the end stages 3 are cooled by a small amount of air at atmospheric or lower pressure drawn in through conduit 16 and discharged through conduit 17. Alternatively, valves 14 and 21 may be opened just sufficiently to allow enough air to enter the end stages 3 from the conduit 15 to cool them. In either case, surging in the end stages 3 is prevented by cylindrical slide valves 22, which are moved axially to throttle the impeller inlet of each end stage 3. The valves may be operated automatically or manually. Valve 12 may be a non-return valve.