Casings for the outflow of gases from axial flow and radial flow compressors

摘要

761,216. Centrifugal and axial-flow compressors. SULZER FRERES SOC. ANON. Dec. 9, 1954 [Dec. 12, 1953], No. 35723/54. Class 110 (1). A casing for the outflow of gas from a compressor comprises an annular inlet passage 8 through which gas coming from the compressor is introduced tangentially into a toroidal chamber 9, and two discharge passages 2 leading from the toroidal chamber through which the gas flows away in two separate streams rotating helically in opposite directions as indicated by the arrows 10, 11. The casing is shown with part, including one of the discharge passages 2, cut away; each half of the casing on either side of the plane I-I is a mirror image of the other half. The gas discharged by an axial-flow compressor divides at the arrow 5 and also at the arrow 7 to form two pairs of helical streams flowing towards opposite discharge passages 2 and uniting to form the two oppositely rotating helical streams indicated by the arrows 10, 11. Passage 8 is separated from the toroidal chamber 9 by a wall 12 and increases in crosssectional area from inlet to outlet to act as a diffuser; it deflects the gas from its original axial direction through 150-180 degrees. The maximum cross-sectional dimension AB of the toroidal chamber 9 should not exceed 1.5 times the minimum cross-sectional dimension CD; the smallest radius of curvature r should be at least 25 per cent of the dimension CD. In the case of a radial-flow compressor, the gas may enter the chamber 9 tangentially at the position indicated at B, and the rotation may be in the directions of the arrows 10, 11 or in the opposite directions.