US 11,788,533 B2
Multistage centrifugal pump
Marc Widmer, Winterthur (CH); and Daniele Cimmino, Figino (CH)
Assigned to SULZER MANAGEMENT AG, Winterthur (CH)
Filed by Sulzer Management AG, Winterthur (CH)
Filed on Jun. 29, 2022, as Appl. No. 17/853,295.
Claims priority of application No. 21184022 (EP), filed on Jul. 6, 2021.
Prior Publication US 2023/0011820 A1, Jan. 12, 2023
Int. Cl. F04D 1/10 (2006.01); F04D 1/06 (2006.01); F04D 15/00 (2006.01); F04D 27/02 (2006.01); F04D 29/22 (2006.01)
CPC F04D 1/10 (2013.01) [F04D 1/06 (2013.01); F04D 15/0005 (2013.01); F04D 27/023 (2013.01); F04D 27/0215 (2013.01); F04D 27/0238 (2013.01); F04D 29/2222 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A multistage centrifugal pump for conveying a fluid, comprising:
a pump housing with an inlet to receive the fluid and an outlet to discharge the fluid;
a first stage impeller and a last stage impeller configured to convey the fluid from the inlet along a flow path to the outlet;
a shaft configured to rotate the first stage impeller and the last stage impeller about an axial direction;
a suction chamber arranged upstream of the first stage impeller and in fluid communication with the inlet;
a recirculation path for the fluid comprising a return opening and extending from the return opening to the suction chamber, the return opening located at or in the flow path downstream of the first stage impeller and upstream of the last stage impeller; and
a flow control rod disposed in the recirculation path, the flow control rod configured to adjust a recirculation flow through the recirculation path into the suction chamber and configured and arranged to be removable from and insertable into the recirculation path from an outside of the centrifugal pump.