GB727297A - Multistage compressor - Google Patents

Abstract

727,297. Centrifugal compressors. GARRETT CORPORATION. June 15, 1953 [June 30, 1952], No. 16425/53. Class 110 (1). A multi-stage compressor comprises a first stage impeller having separate inlets on opposite sides and a peripheral discharge, a second stage impeller mounted on the same shaft, and means for conducting fluid discharged from the first stage impeller over one of the inlets to the second stage impeller. The casing of a twostage compressor comprises an end section B, Fig. 3, attached at a flange 21 to an intermediate section C. A further end section A has a flange 20 which is connected by bolts 24 to a flange 23 on the section C, with a diffuser ring 25 clamped between the flanges. The first stage impeller 34 draws in air through screens 15, 29 and passages 14, 28 and discharges by way of stator vanes 45 to tangential outlet ducts 46. Each duct 46 is connected to a corresponding passage 31 by means of a diffuser 48, Figs. 3 and 4, which is bolted in place at flanges 49 and 50. Guide vanes 51 are provided. The passages 31, which are separated by webs 30, lead to the second stage impeller 35, which discharges by way of a diffuser 53 to a volute 16. The impellers 34, 35 are carried by a hollow shaft 33 which has a splined connection at 39 with a driving shaft 38 which is connected to a gas turbine or other driving means. Auxiliaries are driven through a shaft 40 splined at 41 to the shaft 33. Sealing is provided at each impeller eye by means of a ring 57, Figs. 3 and 5, carried by the impeller and having circumferential grooves which co-operate with flexible bands 58 supported as by a stationary ring 59. Flanges 55 on a bush 54 co-operate with flanges 56 on the shaft 33 to form a labyrinth seal.