Diffuser for single-celled centrifugal pump of multi-stage pump, has helical blades with projections whose cooperation with notches in flange and/or envelope permits to maintain blades in position between inner flange and outer envelope

摘要

The diffuser has helical blades (1) with projections (9, 10) on their edges, where the projections are distributed at distant points on the blade length. The blades are mounted between an inner flange (3) and an outer envelope with the projections engaged in notches made in the flange and/or the envelope. The cooperation of the projections and the notches permits to maintain the blades in position between the flange and the envelope. The envelope has four parts namely upper internal part (2a), lower internal part (2b), upper external part (2c) and lower external part (2d), where the parts (2a, 2b) have flange rings (6a, 6b). Independent claims are also included for the following: (A) a centrifugal pump including a diffuser (B) a method of fabricating a diffuser of a pump.