GB1393955A - Rotodynamic compressors - Google Patents

Abstract

1393955 Centrifugal compressors SULZER BROS Ltd 5 July 1972 [12 July 1971] 31500/72 Heading F1C The invention relates to a roto-dynamic compressor and to means for preventing part of the shaft bearing which is adjacent the inlet passage of the compressor from being excessively cooled. The compressor shown is of the four-stage centrifugal type comprising a shaft 14 on which are mounted four impellers 10, 11, 12, 13, the compressor having an inlet 1 and a discharge 15, the shaft being mounted in bearings 2 and 16 adjacent the inlet and discharge ends. The bearing housing 2 has a portion 17 which projects towards the inlet passage 32 and means are provided to prevent this becoming excessively cooled thereby preventing the possibility of lubricating oil passing into the working passage of the compressor. A partition member 30 is mounted within the inlet passage so as to form two chambers 31, 32, the chamber 31 being adjacent the projection 17 and the chamber 32 constituting the remainder of the inlet passage, the two chambers being connected by means of an annular gap 33 adjacent the shaft. Relatively warm air is supplied to the chamber 31 through duct 36 and bore 35 in the casing, the air being taken from a chamber 38 adjacent the discharge end of the compressor. A heater device 46 may be provided in the duct 36. The chamber 38 is at the low-pressure side of a labyrinth seal 4. In Fig. 2 air supply to the chamber 31 is taken from the outlet of the first stage impeller 10, the air being heated in a heater 53. In a further embodiment air is taken from the inlet passage 32 and passed by means of a pump and a heater to the chamber 31 while in a further embodiment fluid is taken from a reservoir at a suitable pressure and temperature.