Centrifugal Pump Wear Ring and Liner Design for Slurry

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Solution Overview

Problem

Centrifugal pumps used for slurries face significant wear issues due to abrasive action of slurry particles, leading to reduced hydraulic performance and efficiency, and premature failure, particularly on the suction side of the impeller and casing, which results in frequent maintenance shutdowns and economic losses.

Innovation Solution

A centrifugal pump design with an annular liner diameter 1.18 to 1.22 times that of the impeller, combined with an axially adjustable wear ring and increased expelling vanes, along with a modular, replaceable suction-liner and extended cutwater clearance, which reduces wear by minimizing turbulence and allowing for periodic replacement of worn components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional centrifugal pump design is used, then initial hydraulic performance is achieved, but wear on suction side of impeller and casing increases clearance and reduces performance over time

Engineering Contradiction:
Improvehydraulic performance stabilityVSAvoidabrasive wear
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A wear ring is introduced as an intermediary component between the impeller and the pump casing. This wear ring absorbs the abrasive wear that would otherwise occur on the main casing components, maintaining the clearance between the impeller and casing while protecting the permanent casing structure. The wear ring can be periodically replaced without replacing the entire pump casing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pump casing is divided into permanent and replaceable components. The wear ring is made replaceable while the main casing remains permanent. This segmentation allows selective replacement of only the worn components (wear ring, liner, impeller) while retaining the permanent casing structure, thereby maintaining hydraulic performance stability over extended periods.

Inventive Principle:
Principle #1Segmentation

2Productivity

If expelling vanes are added to reduce bypass recirculation, then hydraulic performance is improved, but localized turbulence increases wear on casing liner

Engineering Contradiction:
Improvehydraulic efficiencyVSAvoidlocalized abrasion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The wear ring serves as a mediator that protects the casing liner from the localized turbulence and abrasion caused by expelling vanes. By positioning the wear ring between the expelling vanes and the casing liner, it absorbs the harmful localized wear while allowing the expelling vanes to continue their function of reducing bypass recirculation and improving hydraulic efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Different parts of the pump have different protection strategies. The suction side area subject to localized turbulence from expelling vanes receives additional protection through the wear ring and modular liner, while other areas use standard design. This local quality approach applies enhanced wear protection specifically where needed without compromising overall hydraulic performance.

Inventive Principle:
Principle #3Local quality

3Ease of repair

If modular replaceable components are implemented, then maintenance flexibility is improved, but device complexity increases

Engineering Contradiction:
Improvecomponent replaceabilityVSAvoidstructural complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The pump is segmented into modular components (permanent casing, replaceable wear ring, replaceable liner, replaceable impeller) that can be independently maintained. The wear ring is designed as a simple axially adjustable component that can be replaced without complex disassembly, and the liner is provided as a separate replaceable module, simplifying maintenance while managing structural complexity through standardized interfaces.

Inventive Principle:
Principle #1Segmentation

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 design extends the service life of the pump by reducing wear on the peripheral casing walls and maintaining hydraulic performance, enabling operation beyond the service life of comparable pumps with reduced downtime and maintenance needs.

Implementation Method 1

The rotating impeller of the pump produces a pressure differential that moves the slurry from the axial input port to the radial discharge section of the pump. The centrifugal force generated by the impeller produces suction at the input port and causes the slurry to discharge at relatively high velocities with a radial component

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

these vanes promote discharge of the particles and also reduce bypass recirculation... the higher expelling vanes and clearance between the impeller and the casing front wall proved to create localized increases in slurry turbulence

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2697516B1Low-wear slurry pump
Publication Date: 2020.07.29 F L SMIDTH & CO AS
  • EP2697516B1 patent drawingFigure 1
  • EP2697516B1 patent drawingFigure 2
  • EP2697516B1 patent drawingFigure 3

AI summary

A centrifugal pump for a slurry combines design changes with respect to conventional configurations that produce quasi-laminar flow and materially extend the life of the casing. The cutwater clearance of the casing is increased to a range of 0.20 to 0.25 times the diameter of the impeller. The casing includes a redesigned removable annular liner with a diameter increased to at least 1.15 times the diameter of the impeller. The pump preferably also has an axially adjustable wear ring with a diameter increased such that it extends by at least 10% over the diameter of the area of interface between the wear ring and the impeller.