GB604121A - Improvements in diffusers for centrifugal type compressors and pumps - Google Patents

Abstract

604,121. Centrifugal pumps. BRITISH THOMSON-HOUSTON CO., Ltd., and FORSLING, B. E. G. Sept. 18, 1944, No. 17778. [Class 110 (i)] A helico-centrifugal compressor is provided with a diffuser having an outer wall 3 of spherical shape and blades which are everywhere radial to the centre o of the spherical wall. The spherical form extends from the blade inlet edges ab to the plane of and the outer wall beyond that may be cylindrical or conical and the vanes may continue to be radial too o or radial to the axis. The blades make a large angle with the axis as shown in Fig. 2. They may be of sheet material cast into the inner wall 2, or may be cast integral with the part 2 and have.radiused roots except near the inlet. The diffuser is preceded by a vaneless.space a, b, V-v. Beyond the diffuser, there is a continuation guide passage 5 having half as many blades as the - diffuser. This passage is provided in a casting which serves to unite the parts 2 and 3. The diffuser blade inlet edges may be radial to o, or shaped as shown at a, b to get a correct entry angle over the whole inlet edge. The number of blades is such' that the inter-blade passages have an approximately square cross-section and the passages have a divergence in both width and height of about 7 degrees. The pump impeller is of the kind described in Specifications 594,537 and 594,538.