Serrated Impeller Stabilizes Centrifugal Pump Pressure

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Solution Overview

Problem

Centrifugal pumps face challenges in maintaining a constant pressure rise across varying flow rates, leading to inefficiencies at low flow rates and increased power consumption when using stability valves or less efficient pumps to mitigate these issues.

Innovation Solution

The design incorporates a serrated impeller with a disc-shaped shroud and baseplate featuring major and minor teeth serrations, which imparts additional momentum to the fluid at low flow rates, reducing pressure rise variance across a broad spectrum of flow rates without the need for stability valves or less efficient pumps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a less efficient centrifugal pump is used to increase internal leakages, then pressure rise stability across varying flow rates is improved, but thermal efficiency and power consumption worsen

Engineering Contradiction:
Improvepressure rise stabilityVSAvoidthermal efficiency
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The invention applies local quality by introducing serrations only at specific locations on the impeller (periphery of shroud and baseplate) rather than modifying the entire pump system. These localized serrated features create controlled turbulence and eddy currents only where needed to stabilize pressure rise, while the rest of the pump maintains its high efficiency design without excessive internal leakages.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If a stability valve is incorporated into the system, then pressure rise stability across varying flow rates is improved, but power consumption and system complexity increase

Engineering Contradiction:
Improvepressure rise stabilityVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the need for external stability valves by integrating the pressure stabilization function directly into the impeller structure. The serrations on the impeller periphery perform the pressure stabilization function that would otherwise require a separate stability valve component, thereby reducing system complexity while maintaining pressure rise stability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If a stability valve is incorporated into the system, then pressure rise stability across varying flow rates is improved, but pressure output decreases

Engineering Contradiction:
Improvepressure rise stabilityVSAvoidpressure output
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The serrations on the impeller act as an intermediary mechanism that stabilizes pressure rise without the detrimental effects of stability valves. Instead of creating a fixed orifice that reduces overall pressure output, the serrations generate controlled eddy currents and turbulence that stabilize pressure while allowing the pump to maintain its full pressure output capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The serrated impeller design achieves a more consistent pressure rise across flow rates, eliminating the need for stability valves and less efficient pumps, while maintaining thermal efficiency and low power consumption.

Implementation Method 1

a plurality of serrations formed circumferentially along a periphery of the shroud... a plurality of serrations formed circumferentially along a periphery of the baseplate

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

an impeller is a rotating component of a centrifugal pump which transfers energy from the power source that drives the pump to the fluid being pumped by accelerating the fluid outward from the center of rotation

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3341613B1Centrifugal pump with serrated impeller
Publication Date: 2024.12.18 WOODWARD INC
  • EP3341613B1 patent drawingFigure 1
  • EP3341613B1 patent drawingFigure 2
  • EP3341613B1 patent drawingFigure 3~4

AI summary

A centrifugal pump and an impeller thereof are provided. The impeller defines an outer peripheral edge which includes a plurality of serrations circumferentially thereon. The plurality of serrations are configured such that additional power and momentum are transferred to a working fluid of the pump, which results in an additional pressure rise in the working fluid at relatively low flow rates of the centrifugal pump.