Agitator Ball Mill Return Conveyor Elements

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In agitator ball mills, grinding bodies often accumulate at the periphery of the grinding chamber due to high kinetic energy, leading to separation from the material being ground, increased pressure, vibrations, and sub-optimum grinding results.

Innovation Solution

The introduction of return conveyor elements, arranged laterally on the agitator elements or as separate units, creates a flow-field directed inwardly, enhancing tractive forces and ensuring grinding bodies are carried along with the material into the grinding body cycle, preventing accumulation at the periphery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the kinetic energy of grinding bodies is increased, then grinding effectiveness is improved, but separation between grinding bodies and material occurs leading to accumulation at periphery

Engineering Contradiction:

Improvegrinding effectivenessVSAvoidmixing uniformity

Core Design Contradiction:

PowerVSStability of the object's composition

Solution Approach 1:

The grinding chamber is divided into multiple conveyor chambers arranged axially on the agitator shaft. Each conveyor chamber independently conveys material and grinding bodies, creating multiple flow paths that prevent centrifugal separation while maintaining high kinetic energy for effective grinding.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conveyor chambers act as intermediaries that guide both grinding bodies and material together through controlled paths. This intermediary structure ensures that high-speed grinding bodies remain mixed with material by constraining their motion within the chamber boundaries rather than allowing free radial movement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If grinding bodies are conveyed radially outwards with high speed, then grinding force is enhanced, but vibrations occur due to pressure buildup

Engineering Contradiction:

Improvegrinding forceVSAvoidvibrations

Core Design Contradiction:

ForceVSObject-affected harmful factors

Solution Approach 1:

The single large grinding chamber is segmented into multiple smaller conveyor chambers. This segmentation distributes the grinding bodies and material flow across multiple zones, preventing localized pressure buildup that causes vibrations while maintaining sufficient grinding force in each chamber.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conveyor chambers create periodic flow patterns as material and grinding bodies are sequentially conveyed through each chamber. This periodic action prevents continuous pressure buildup and associated vibrations while maintaining consistent grinding force through repeated cycles of conveyance and discharge.

Inventive Principle:

Principle #19Periodic action

3Productivity

If paddle-wheel-like agitator elements are used, then material conveyance is improved, but grinding bodies accumulate at periphery

Engineering Contradiction:

Improvematerial conveyance efficiencyVSAvoidgrinding body distribution

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The continuous paddle-wheel structure is replaced with discrete conveyor chambers arranged axially. Each chamber acts as a separate conveying unit that positively transports both material and grinding bodies, preventing the centrifugal separation that occurs with traditional paddle-wheel designs while maintaining conveyance efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the grinding chamber are created with distinct functions: conveyor chambers for material transport and inter-chamber regions for grinding body circulation. This local differentiation ensures that grinding bodies remain distributed throughout the system rather than accumulating at the periphery, while material conveyance remains efficient.

Inventive Principle:

Principle #3Local quality

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 solution effectively maintains the grinding body cycle, reducing vibrations and improving grinding efficiency by ensuring grinding bodies are uniformly distributed and processed, leading to enhanced product quality and mill stability.

Implementation Method 1

The return conveyor elements generate a flow-field directed inwards towards the agitator shaft, which increases the tractive forces of the material being ground and/or dispersed

Methodology Applied

Scientific EffectFlow-field:

Implementation Method 2

the tractive forces of the material being ground and/or dispersed

Methodology Applied

Scientific EffectTractive forces: Friction

Data Source

PatentUS10464069B2Agitator ball mill

Publication Date: 2019.11.05 WILLY A BACHOFEN AG

AI summary

An agitator ball mill includes a grinding chamber, a rotatably mounted agitator shaft, which protrudes into the grinding chamber and on which agitator elements, in the form of paddle wheels, are arranged spaced apart from one another axially, and an inlet for supplying material to be ground and grinding bodies and an outlet for removal of the ground material. The agitator elements are constructed in such a way that, during operation, they convey a mixture consisting of material to be ground or dispersed and grinding bodies through their interior outwards away from the agitator shaft. In the grinding chamber there are arranged return conveyor elements which are joined to the agitator shaft for conjoint rotation therewith and which convey the mixture laterally alongside and/or between the agitator elements inwards towards the agitator shaft.