GB619617A - Improvements in and relating to centrifugal impellers - Google Patents

Abstract

619,617. Centrifugal compressors ; turbines. BRITISH THOMSON-HOUSTON CO., Ltd. Dec. 16, 1946, No. 37044. Convention date, Dec. 20, 1945. [Classes 110 (i) and 110 (iii)] Each blade has an inlet portion 4 tipped forwardly to form an acute angle with the plane of rotation, an intermediate portion 5 sloped forwardly relative to a radial line through the impeller axis, and a final portion 6 sloped backwardly. The impeller body 8 is of approximately hyperboloidal shape, the axial length being approximately equal to the major radius. The inlet portion 4 comprises 20-40 per cent of the mean flow path 1 and the final portion 6 comprises 10-30 per cent of the path. The cross-sectional area of the flow passage decreases by 10-30 per cent through the inlet portion 4 and thereafter may continue to decrease slightly or may remain constant or increase. The reduction in area may be effected by reducing the dimension of the flow passage measured in a direction normal to the surface of the body 8 or by thickening the blade3 or by both methods. The impeller may be shrouded. Specifications 532,008 and 589,689 are referred to. The Specification as open to inspection under Sect. 91, also comprises the statement that the invention is applicable to turbine rotors, the motive fluid being directed by nozzles radially inwards to the blade portions 6. This subjectmatter does not appear in the Specification as accepted.