GB741797A - Rotors for centrifugal pumps, blowers and compressors - Google Patents

Abstract

741,797. Centrifugal pumps &c. SULZER FRERES SOC. ANON. Dec. 21, 1953, No. 25446/53. Class 110(1) In an impeller for a centrifugal pump, blower or compressor, each blade has an inner section 3 and an outer section 4, both approximately straight and of approximately equal length and inclined to each other at an obtuse angle with a smooth transition curve at the junction 5, and the outer section 4 of one blade S forms with the inner section 3 of the next following blade T a backwardly directed divergent diffuser channel 6 with a straight axis 7. The angle of divergence is about 10 degrees. The inlet channel 12 formed by the surface 11 of blade S and the inner end 10 of blade T is convergent. The surface 14 is preferably convex, while the surfaces, 8, 9, 11 are flat. At the outlet from the diffuser 6, the fluid stream divides into a front branch 17 and a rear branch 18, separated by an eddy space 20 which supports the branch 17 and tends to keep it parallel to the surface 8. Beyond the trailing edge 15, the branch 17 impinges against and deflects the branch 18 from the preceding blade channel and the combined stream has an outlet angle # which is between the outlet angles of the two branches. It is stated to be known to provide rotor blades which are continuously curved from the leading edge to the trailing edge, the curve being an involute or a logarithmic spiral.