Centrifugal Pump Partition Wall Flow Opening

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Solution Overview

Problem

Centrifugal pumps driven by glandless motors experience noise issues due to turbulence at the partition wall between the pump chamber and the canned chamber, leading to annoying high-frequency whistling noises.

Innovation Solution

The flow through the through-flow opening is designed to avoid noise-generating turbulences by ensuring there are no sharp edges, with features such as a chamfered or rounded edge at the narrowest point of the opening, typically with a diameter of 1 to 3 mm, and a conical shape that reduces cross-sectional area, preventing edge interactions that cause pressure pulsations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the partition wall has a simple through-flow opening, then the device complexity is low, but turbulence occurs at the opening causing noise

Engineering Contradiction:
Improvepartition wall structureVSAvoidnoise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent applies curvature by rounding the edges of the through-flow opening instead of using sharp edges. Specifically, the opening is designed with a rounded contour that eliminates sharp corners, causing the liquid flow to follow a curved path through the opening. This curvature prevents flow separation and turbulence that would otherwise occur at sharp edges, thereby reducing noise generation while maintaining a relatively simple partition wall structure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Manufacturing precision

If the flow opening has sharp edges, then the manufacturing precision is easier to achieve, but sharp edges generate turbulence and pressure pulsations

Engineering Contradiction:
Improveflow opening geometryVSAvoidturbulence
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces sharp edges with rounded edges at the through-flow opening. The rounded contour is designed to guide the liquid flow smoothly through the opening, preventing flow separation and turbulence. While this requires slightly more complex manufacturing than simple circular openings, it significantly reduces turbulence and pressure pulsations, eliminating the harmful noise effects.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design effectively eliminates noise by minimizing turbulence and pressure pulsations, providing a quieter operation for the motor-driven centrifugal pump.

Implementation Method 1

when the flow passes through the flow opening in the dividing wall, turbulence occurs at the flow opening, which leads to considerable noise with high frequencies

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

the interaction of these turbulences with the opposite edge, which can excite pressure pulsations in the flow opening, is avoided

Methodology Applied
Scientific EffectFlow separation: Flow Separation

Data Source

PatentEP2100041B1Motor centrifugal pump
Publication Date: 2019.06.12 WILO SE
  • EP2100041B1 patent drawingFigure 1
  • EP2100041B1 patent drawingFigure 2~5

AI summary

The invention relates to a motor centrifugal pump, comprising an impeller supported in the pump space, the impeller being positioned on the electric motor shaft, wherein the motor rotor is incorporated in a can chamber through which the pumped fluid flows, and the pump space of the chamber is separated by a separating wall having at least one flow opening for the pumped fluid, wherein the size of the cross-section of the flow opening decreases or increases from the pump space toward the can chamber.