Multistage Centrifugal Pump With Axial Collector Chamber Layout

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Solution Overview

Problem

Existing multistage pumps have large outer diameters and weights due to the radial arrangement of the collector chamber around the diffuser of the last stage, which increases material and space requirements and fixing element loads.

Innovation Solution

The collector chamber is displaced axially with respect to the diffuser of the last stage, reducing the overall outer diameter and weight of the pump by arranging it behind the diffuser, and allowing for a more compact design without compromising efficiency or reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the collector chamber is arranged radially around the diffuser of the last stage, then the pump can handle high pressure applications, but the outer diameter and weight of the pump increase

Engineering Contradiction:
Improvepressure generation capabilityVSAvoidpump weight
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The collector chamber is relocated from a radial arrangement (in the plane perpendicular to the pump shaft) to an axial arrangement (along the pump shaft axis). This dimensional change allows the collector chamber to be positioned behind the diffuser in the axial direction, eliminating the need for a large radial envelope and thereby reducing the pump's outer diameter and weight while maintaining pressure generation capability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the collector chamber is arranged radially around the diffuser, then the pump structure is conventional, but the material requirements and space requirements increase

Engineering Contradiction:
Improvestructural configurationVSAvoidpump volume
Core Design Contradiction:
Device complexityVSVolume of stationary object

Solution Approach 1:

By transitioning from radial to axial arrangement of the collector chamber, the pump achieves a more compact volumetric configuration. The axial placement behind the diffuser utilizes the available length along the pump shaft, reducing the radial footprint and overall volume without compromising the functional requirements for high pressure applications

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If the collector chamber is arranged radially around the diffuser, then the pump design is conventional, but the fixing element loads increase

Engineering Contradiction:
Improvedesign configurationVSAvoidfixing element load
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The axial arrangement of the collector chamber behind the diffuser redistributes the mechanical loads on fixing elements. By positioning the collector chamber in the axial direction rather than radially, the leverage and moment arms on mounting bolts and support structures are reduced, thereby decreasing the loads on fixing elements while maintaining the structural integrity required for high pressure operation

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration reduces the overall dimensions, weight, and material requirements, while maintaining efficiency and reliability, and allows for smaller fixing elements, thereby lowering costs and pressure boundary stresses.

Implementation Method 1

a diffuser configured to surround the impeller and to receive the fluid from the impeller

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

an impeller for acting on the fluid... all impellers are arranged on a common pump shaft one after another. The pump shaft is driven for a rotation about an axial direction

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

guide channels configured to receive the fluid from the particular diffusor and to guide the fluid to the impeller of the next stage

Methodology Applied
Scientific EffectFluid flow guidance:

Data Source

PatentEP3828419B1Multistage centrifugal pump
Publication Date: 2025.12.24 SULZER MANAGEMENT AG
  • EP3828419B1 patent drawingFigure 1
  • EP3828419B1 patent drawingFigure 2
  • EP3828419B1 patent drawingFigure 3

AI summary

A multistage pump for conveying a fluid is proposed, having an outer pump housing (2) and a plurality of stages (3) arranged in the outer pump housing (2), said plurality of stages (3) comprising at least a first stage (31) and a last stage (33), each stage (31, 32, 33) comprising a stage casing (6), an impeller (7) for acting on the fluid, and a diffuser (8) configured to surround the impeller (7) and to receive the fluid from the impeller (7), the multistage pump further comprising a pump inlet (4) for supplying the fluid to the impeller (7) of the first stage (31), a pump outlet (5) for discharging the fluid, and a pump shaft (9) configured for rotating about an axial direction (A), wherein each impeller (7) is mounted to the pump shaft in a torque proof manner, wherein all impellers (7) are arranged one after another on the pump shaft (9), wherein the last stage (33) comprises a collector (10) with a collector chamber (11) configured to receive the fluid from the diffuser (8) of the last stage (33), wherein all other stages (31, 32) than the last stage (33) comprise guide channels (81) configured to receive the fluid from the particular diffusor (8) and to guide the fluid to the impeller (7) of the next stage (32, 33), and wherein the collector chamber (11) is displaced in the axial direction (A) with respect to the diffusor (8) of the last stage (33)..