Composite Lifter Bar with Polyurethane Filler for Wear Resistance

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Solution Overview

Problem

Existing lifter bars in grinding mills face challenges in wear resistance and energy efficiency, as they are typically made from materials that do not effectively manage the wear and tear caused by processing hard solid materials, leading to increased energy consumption and reduced performance.

Innovation Solution

The lifter bar is designed with a composite structure, featuring a metal fixing element and a polyurethane body with enhanced wear resistance, where the polyurethane portion covers 35-85% of the volume, and a reinforced wearing plate is used to enhance durability, allowing for better fitting and reduced energy consumption during manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If lifter bars are made from traditional materials (metal or rubber), then structural strength is maintained, but wear resistance deteriorates

Engineering Contradiction:
Improvestructural strengthVSAvoidwear resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The lifter bar combines a metal base part providing structural strength with a polymeric filler material (urethane, polyethylene, or nylon) providing wear resistance. This composite structure resolves the contradiction by integrating materials with complementary properties - the metal ensures mechanical strength while the polymer ensures wear resistance in the grinding mill environment.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different portions of the lifter bar use different materials optimized for their specific functions: the metal base part (channel or plate) provides structural support and fixing capability, while the polymeric filler material in the recesses provides wear-resistant contact surfaces. This local differentiation of material properties resolves the contradiction between overall strength and localized wear resistance.

Inventive Principle:
Principle #3Local quality

2Reliability

If lifter bars are made from wear-resistant materials, then wear resistance is improved, but energy consumption increases

Engineering Contradiction:
Improvewear resistanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention changes the material parameters by using polymeric filler materials (urethane, polyethylene, nylon) with optimized mechanical properties that provide wear resistance while maintaining lighter weight compared to traditional heavy metal construction. This parameter optimization reduces the energy required to rotate the lifter bars while maintaining wear resistance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The composite structure allows the use of lighter polymeric materials for the wear-resistant portions while maintaining structural integrity through the metal base. This reduces the overall mass of the lifter bar assembly, thereby reducing the energy consumption for rotation while preserving wear resistance where needed.

Inventive Principle:
Principle #40Composite materials

3Reliability

If lifter bars use a composite structure with polymeric filler material, then wear resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvewear resistanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lifter bar is segmented into distinct components: a metal base part with recesses and a separate polymeric filler material. This segmentation allows each component to be manufactured independently using optimized processes (metalworking for the base, molding for the polymer), then assembled together. This reduces manufacturing complexity compared to attempting to create a homogeneous composite material.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The recesses in the metal base part act as intermediaries that receive and retain the polymeric filler material. This intermediary structure simplifies the manufacturing process by providing a predefined container for the polymer, eliminating the need for complex composite material processing techniques and allowing straightforward assembly of the two materials.

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 composite structure of the lifter bar with polyurethane and metal components provides improved wear resistance and energy efficiency, resulting in reduced energy consumption and enhanced performance by effectively lifting and crushing materials in grinding mills.

Implementation Method 1

the base part is produced from reactive resin, which polymerises, in situ, on contact with the adjacent surface of the cap

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP3206799B1Lifter bar, method for making a lifter bar, method for assembling a lifter bar and a grinding mill
Publication Date: 2021.04.28 METSO OUTOTEC FINLAND OY
  • EP3206799B1 patent drawingFigure 1~2
  • EP3206799B1 patent drawingFigure 3
  • EP3206799B1 patent drawingFigure 4

AI summary

This relates a lifter bar (1),method for making a lifter bar (1), a method for assembling a lifter bar and a grinding mill (3) for ore grinding. The lifter bar (1) comprises a lifter bar body (10) having an outer surface conforming the outer surface (1a) of the lifter bar (1), and a fixing element (11) for connecting the lifter bar (1) to the shell (2) of the grinding mill (3). The lifter bar body (10) further comprises a first portion (10a) and a second portion (10b) forming a continuous lifter bar body (10). The fixing element is embedded to the first portion (10a) such that it forms part of the fixing surface(1b) of the lifter bar (1). The second portion (10b) is made of polyurethane and forming 35 –85 % of the volume of the lifter bar (1).