GB1500552A - Multistage centrifugal pumps - Google Patents

Abstract

1500552 Centrifugal pumps SULZER BROS Ltd 3 July 1975 [3 July 1974] 28049/75 Heading F1C A multi-stage centrifugal pump comprises an inner casing 3 containing the pump stages and having an inlet passage or passages 29a, 29b, an intermediate discharge passage 30, a re-entry inlet passage (not shown) and a final discharge passage or passages 27; and an outer casing 9 at least partly surrounding the inner casing and having an inlet connection 19, an intermediate discharge connection 20, a re-entry inlet connection 21 and a final discharge connection 22; the outer casing containing chambers 4-8 which are partly bounded by circumferentially extending shell walls 10, 11, 12, 42 and generally axially transverse partition walls 17, 18, 25, 44, there being paths connecting the passage to the respective connections, each path including at least one of the chambers. Axially extending partitions 13 separate the chamber 5 from the chambers 4, 6. The fluid flows from inlet connection 19 via chamber 4 to the inlets 29a, 29b of the first-stage impellers and leaves the first stage via a double volute 30, pipes 35, ports 26, chamber 5 and connection 20. After treatment (cleaning, heating or cooling), the fluid is readmitted via connection 21, chamber 6, ports 24 and chamber 7 to pass through the intermediate and high-pressure stages of the pump, finally being discharged via ports 27, chamber 8 and connection 22. The cylindrical outer wall 31 of the volute 30 is separate from the inner casing 3 and connected by struts 37 to the outer casing. Partitions 17, 18, 32, 33, 44 are part of the inner casing and are sealed to the outer casing by seal rings 43. The inner casing can be withdrawn upwardly from the outer casing.