Counter Rotation Inducer Housing for Centrifugal Pumps

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Spiral inducers in centrifugal pumps face inefficiencies as fluid rotates with the blades, leading to increased net positive suction head requirements and cavitation issues, which hinder efficient fluid movement and pump performance.

Innovation Solution

The incorporation of helical grooves or vanes in the inducer housing that counter-rotate to the blade rotation, capturing and guiding fluid into the impeller or pump, thereby enhancing fluid movement and reducing net positive suction head requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If spiral inducers are used in centrifugal pumps, then fluid can be moved through the pump, but the fluid rotates with the inducer blades which reduces fluid movement efficiency and increases net positive suction head requirements

Engineering Contradiction:

Improvefluid movement efficiencyVSAvoidnet positive suction head requirement

Core Design Contradiction:

ProductivityVSStress or pressure

Solution Approach 1:

The patent applies counter-rotation by configuring the inducer blades to rotate in the opposite direction to the fluid rotation. This inversion principle directly addresses the problem of fluid rotating with the blades by reversing the blade rotation direction, thereby improving fluid movement efficiency and reducing net positive suction head requirements.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the rotational parameter of the inducer blades by introducing counter-rotation. This parameter change modifies the interaction between the blades and fluid, transforming the harmful co-rotation into beneficial counter-rotation, which enhances fluid movement and reduces pressure requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If net positive suction head requirements are increased to prevent cavitation, then cavitation in the inducer and pump is reduced, but cavitation occurs in the tank as fluid level drops

Engineering Contradiction:

Improvecavitation prevention in inducer and pumpVSAvoidfluid pumping capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

By inverting the rotation direction of the inducer blades relative to the fluid rotation, the patent prevents cavitation in the inducer and pump while maintaining lower net positive suction head requirements. This counter-rotation approach eliminates the need to increase NPSH to prevent cavitation, thereby preserving fluid pumping capability.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If tight clearance is created between inducer blades and housing to prevent fluid rotation, then fluid movement is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvefluid movement efficiencyVSAvoidclearance between blades and housing

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

Instead of relying on tight clearances to prevent fluid rotation, the patent inverts the approach by using counter-rotation of the blades. This eliminates the need for tight clearances between blades and housing, thereby improving fluid movement efficiency without increasing manufacturing precision requirements.

Inventive Principle:

Principle #13The other way round (Inversion)

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 improves fluid efficiency and reduces cavitation risks, allowing the pump to operate more effectively and efficiently by moving fluid to a lower level within the tank without increasing net positive suction head requirements.

Implementation Method 1

grooves or vanes that are helical in nature and in counter rotation with respect to the rotation of the blades of the inducer, which grooves or vanes capture fluid rotating with the inducer blades and use that rotation to move the fluid up along the grooves or vanes

Methodology Applied

Scientific EffectCounter-rotation:

Implementation Method 2

grooves or vanes that are helical in nature

Methodology Applied

Scientific EffectHelical flow:

Implementation Method 3

spiral inducers used within centrifugal pumps

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

Inducers are used in such systems to prevent the fluid being moved from cavitating in the impeller or pump, which can occur when there is not enough pressure to keep the liquid from vaporizing

Methodology Applied

Scientific EffectCavitation prevention: Cavitation

Data Source

PatentUS8506236B2Counter rotation inducer housing

Publication Date: 2013.08.13 ELLIOTT CO

AI summary

An inducer with an exterior housing and/or interior hub that incorporates grooves or vanes that are helical in nature and in counter rotation with respect to the rotation of the blades of the inducer, which grooves or vanes capture fluid rotating with the inducer blades and use that rotation to guide the fluid up along paths formed by the grooves or vanes and into an impeller, pump or other device.