Open-Ended Grinding Mill Double-Wall Structure for Oil Isolation

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Solution Overview

Problem

Grinding mills face performance limitations due to restricted material transfer rates and grinding efficiency, especially in larger sizes, caused by slurry flow back and short circuiting, and there is a risk of material contamination from bearing oil leakage.

Innovation Solution

A grinding mill design featuring a split shell and support structure with a double-wall configuration that separates the bearing from the grinding material, using indexed segments and a support structure to prevent oil contact, allowing for open-ended operation without weld defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a SAG mill is used for grinding ore, then coarse grinding is achieved, but fine grinding capability is insufficient

Engineering Contradiction:
Improvegrinding finenessVSAvoidgrinding stage capability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent combines a SAG mill and a ball mill into a single integrated grinding chamber, allowing the system to perform both coarse grinding (SAG mill function) and fine grinding (ball mill function) simultaneously. This merging resolves the contradiction by enabling both grinding stages in one device, eliminating the need for separate mills and improving overall grinding fineness while maintaining versatility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated mill is designed to perform multiple functions: coarse grinding via SAG mill action and fine grinding via ball mill action. The grinding chamber can accommodate both types of grinding media and operations, making the device universal and adaptable to different grinding requirements, thus resolving the contradiction between fine grinding capability and grinding stage versatility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple separate mills are used for different grinding stages, then specific grinding functions are achieved, but device complexity and space requirements increase

Engineering Contradiction:
Improvegrinding function specializationVSAvoidnumber of milling devices
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple separate grinding mills (SAG mill and ball mill) into a single integrated device with one grinding chamber. This consolidation maintains the specialized grinding functions of each mill type while reducing the total number of devices, thereby decreasing device complexity and space requirements while preserving grinding function specialization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated mill design allows a single device to perform multiple specialized grinding functions through different grinding media and operational modes. The grinding chamber can be configured for coarse grinding with SAG mill media or fine grinding with ball mill media, maintaining functional specialization without requiring separate dedicated mills for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If traditional separate milling systems are used, then each mill is optimized for its specific function, but overall system efficiency and resource utilization decrease

Engineering Contradiction:
Improvesystem efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent combines multiple grinding operations into a single integrated system that processes ore through both coarse and fine grinding stages sequentially within one continuous flow. This eliminates the need for intermediate transfer operations between separate mills, reducing energy loss and improving overall system efficiency while maintaining optimized grinding functions for each stage.

Inventive Principle:
Principle #5Merging (Combining)

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

Prevents material contamination and enhances grinding efficiency by ensuring a continuous path is not formed between the bearing and grinding material, enabling larger mill diameters and improved material transfer.

Implementation Method 1

A rod mill is a type of grinder used to grind materials to extremely fine powder as it falls

Methodology Applied
Scientific EffectImpact: Impact Force

Implementation Method 2

A rod mill is a type of grinder used to grind materials to extremely fine powder as it falls

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 3

as it falls

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3866980B1A grinding mill
Publication Date: 2026.05.13 METSO OUTOTEC FINLAND OY
  • EP3866980B1 patent drawingFigure 1~2
  • EP3866980B1 patent drawingFigure 3
  • EP3866980B1 patent drawingFigure 4

AI summary

An open-ended grinding mill (1) comprises a drum (2) comprising a cylindrical shell (3), wherein the longitudinal axis (4) of the drum is arranged in a substantially horizontal position in a use position of the grinding mill (1). The drum (2) comprises a first end (5) at the feed end of the shell and a second end (6) at the discharge end of the shell. The grinding mill further comprises a bearing (8) supporting the drum at the second end, and a support structure (9) to connect the drum (2) to the bearing (8). The support structure is configured to provide a wall external to the shell, whereby the shell and the support structure provide a double-wall structure separating the bearing from the inside of the drum.