Rotatable Roller Grate Cooling for High-Temp Material Classification

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Solution Overview

Problem

In the cement or lime industry, existing heat treatment systems face blockages and inefficiencies due to the high temperatures of materials during preheating or calcination, particularly in the classification process between heat treatment stages, where hot materials can exceed 750°C, leading to restrictions in screening devices.

Innovation Solution

A system incorporating a rotatable roller grate with wear-resistant and temperature-resistant elements, partially driven and cooled by a medium, is introduced between the preheater and rotary kiln to separate feed material into different grain fractions, utilizing a cooling medium to maintain functionality under extreme temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a screening device is used to separate material at high temperatures, then classification function is improved, but blockages and restrictions occur due to hot material exceeding 750°C

Engineering Contradiction:
Improveclassification functionVSAvoidblockages and restrictions
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary cooling action by introducing a cooling medium (water or air) through channels in the rotatable elements before the material contacts the screening surface. This pre-cools the elements to prevent thermal damage and blockages, allowing the screening device to reliably classify material at high temperatures without the blockage problems that occur with conventional hot screening devices

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If rotatable elements are used for screening, then classification precision is improved, but wear and temperature resistance are insufficient under extreme conditions

Engineering Contradiction:
Improveclassification precisionVSAvoidwear and temperature resistance
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent employs composite construction for the rotatable elements, combining a base material structure with a specialized outer casing that provides wear and temperature resistance. The cooling channels integrated within the elements create a composite functional structure that simultaneously achieves precise classification through the screening geometry while resisting thermal and mechanical degradation through the protected casing and active cooling system

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The cooling medium acts as an intermediary substance that transfers thermal energy away from the rotatable elements. By introducing this intermediate cooling agent through embedded channels, the patent mediates between the high-temperature classification environment and the rotatable elements, preventing direct thermal damage while maintaining the elements' structural integrity and screening precision

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If cooling medium is supplied to rotatable elements, then temperature resistance is improved, but device complexity increases

Engineering Contradiction:
Improvetemperature resistanceVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling function with the structural design of the rotatable elements themselves by embedding cooling channels directly within the elements. This integration combines what would otherwise be separate systems (screening structure and cooling system) into a unified component, reducing overall device complexity while maintaining effective temperature resistance through the integrated cooling medium supply

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

This solution effectively separates undesirable fine grain fractions, enhances the load-bearing capacity, and prevents blockages, ensuring efficient processing of materials at high temperatures, thereby improving the heat treatment process in the cement or lime industry.

Implementation Method 1

at least one finer grain fraction falling through between the rotatable elements and means for supplying a cooling medium to the rotatable elements being provided

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2136937B1Method and device for heat treatment including method and device for separating or classifying material to be fed
Publication Date: 2014.10.01 THYSSENKRUPP IND SOLUTIONS AG
  • EP2136937B1 patent drawingFigure 1
  • EP2136937B1 patent drawingFigure 2
  • EP2136937B1 patent drawingFigure 3

AI summary

The device (100) according to the invention for separating or classifying material (1) to be fed into at least two different grain fractions (2, 3) comprises a screen device (5), which is formed by rotatable elements (8), particularly a roller table screen, wherein at least one finer grain fraction (2) passes between the rotatable elements (8) and means (14) are provided for cooling the rotatable elements.