US 12,663,009 B2Granted

Multistage pumping system for adaptive offloading of a liquid from a container

AssigneeFlowserve Pte. Ltd.

InventorsMark O'Sullivan, Zachary Procita, Ramakrishnan Rengasamy, Andreas Dreiss, William J. Boyko

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Abstract

A pumping system includes a plurality of interconnected integrated motor/pump modules (IMPs) submerged in a process liquid, such as liquid hydrogen (LH2), within a container, the IMPs being separately controlled by adjustable speed drives (ASDs). The rotation speeds of the IMP impellers are controlled such that the NPSH_A for each IMP remains above a minimum, critical suction head NPSH_c of the IMP, while the outlet pressure and flow of the last IMP is maintained at a specified level unless its NPSH_A falls substantially to its NPSH_c, or until the container is substantially empty. The IMPs can be identical, initially operating at the same speeds, or the first IMP can be an inducer IMP having a reduced NPSH_c. The IMPs can comprise permanent magnets or induction coils attached to their impellers that pass in proximate radial or axial alignment with stator coils. The ASDs can be variable frequency drives (VFDs).

Claims20

Dependent claims

A pumping system configured for pumping a process liquid to an external destination from a container until the container is substantially empty, the pumping system comprising:

a controller;
a plurality of centrifugal integrated pumping modules (IMPs) configured for being submerged in the process liquid, each of the IMPs comprising:
an inlet;
an outlet;
an impeller;
a shaft;
and
a motor;
and
for each of the IMPs, a corresponding adjustable speed drive (ASD) controlled by the controller and configured to cause the motor of the IMP to rotate the impeller of the IMP at a rotation speed that is specified by the controller, the impeller rotation speeds of each of the IMPs being thereby separately controllable by the controller;
wherein for each of the IMPs except a last of the IMPs, the outlet of the IMP is in fluid communication with the inlet of a next one of the IMPs, the inlet of a first of the IMPs being submerged in the process liquid and the output of the last of the IMPS being in fluid communication with the external destination;
and
wherein as a level of the process liquid within the container falls, the controller is configured to separately and continuously adjust the rotation speeds of the impellers of each of the IMPs such that for each of the IMPs, a critical net positive suction head NPSH_c of the IMP remains below an available net positive suction head NPSH_A of the IMP, while an outlet pressure at an outlet of the last IMP is maintained at a specified level until the NPSH_A of the last IMP falls to the NPSH_c of the last IMP, or until the container is empty of the process liquid.

10 more elements

A method of pumping a process liquid from a container until the container is substantially empty, the method comprising:

providing a pumping system comprising:
a controller;
a plurality of centrifugal integrated pumping modules (IMPs) configured for being submerged in the process liquid, each of the IMPs comprising:
an inlet;
an outlet;
an impeller;
a shaft;
and
a motor;
and
for each of the IMPs, a corresponding adjustable speed drive (ASD) controlled by the controller and configured to cause the motor of the IMP to rotate the impeller of the IMP at a rotation speed that is specified by the controller, the impeller rotation speeds of each of the IMPs being thereby separately controllable by the controller;
for each of the IMPs except a last of the IMPs, causing the outlet of the IMP to be in fluid communication with the inlet of a next one of the IMPs;
submerging the inlet of a first of the IMPs in the process liquid;
causing the output of the last of the IMPS to be in fluid communication with the external destination;
causing the impellers of the IMPs to rotate under control of the ASDs according to instructions separately issued to the ASDs by the controller, thereby causing a level of the process liquid within the container to fall as the process liquid is transferred to the external destination;
and
as the level of the process liquid within the container falls, separately and continuously adjusting the rotation speeds of the impellers of each of the IMPs, under control of the ASDs according to instructions issued to the ASDs by the controller, such that for each of the IMPs, a critical net positive suction head NPSH_c of the IMP remains below an available net positive suction head NPSH_A of the IMP, while an outlet pressure at an outlet of the last IMP is maintained at a specified level until the NPSH_A of the last IMP falls to the NPSH_c of the last IMP, or until the container is empty of the process liquid.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/438,039Filed 9 Feb 2024
Published: US 2025/0257731 A114 Aug 2025
Granted: 23 Jun 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

F04D 15/0066
Control, e.g. regulation, of pumps, pumping installations or systems: by changing the speed, e.g. of the driving engine
F04D 1/06
Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps: multi-stage pumps
F04D 7/02
Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts: of centrifugal type
F04D 13/0666
The pump being electrically driven: the motor being of the plane gap type