Dynamic Plank Cooler for Clinker Heat Recovery

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Solution Overview

Problem

Existing clinker coolers face high wear and maintenance issues due to the abrasive nature of hot cement clinker, and previous designs either suffer from excessive wear of moving parts or inefficient heat recovery due to lack of mixing in the bulk material bed.

Innovation Solution

The cooler employs planks with differently designed surfaces that alternately stretch and compress the bulk material bed, promoting vertical mixing and preventing the formation of cold channels, while cooling gas flows through the bed to enhance heat recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a static stair grate is used with a passive clinker layer, then the grate is protected from overheating and abrasion, but the clinker gets into the spaces between stages causing high wear and maintenance intensity

Engineering Contradiction:
Improvegrate protection from overheating and abrasionVSAvoidmaintenance intensity
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent converts the static stair grate into a dynamic system where the grate moves continuously in the conveying direction. This dynamic movement prevents clinker from settling into spaces between stages, eliminating the wear and maintenance issues while still allowing cooling air to pass through the grate to cool the clinker effectively.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If a drag chain is used to pull clinker over a stationary ventilated surface, then clinker transport is achieved, but the drag chain and its moving links suffer heavy wear from hot abrasive clinker

Engineering Contradiction:
Improveclinker transportVSAvoidwear on moving parts
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The entire grate structure moves dynamically with the clinker instead of having stationary surfaces with moving components like drag chains. This eliminates exposed moving parts that would be subjected to abrasive wear from hot clinker, while still achieving effective clinker transport and cooling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent removes the drag chain and its moving links from the system entirely, replacing them with a continuous moving grate surface. This extraction of harmful moving parts eliminates the wear problem while maintaining the essential function of clinker transport over a ventilated surface.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If the entire level is moved forward against a baffle plate, then no machine parts move relative to clinker reducing wear, but very high forces are required and bulk material accumulates on the baffle plate

Engineering Contradiction:
Improvewear on machine partsVSAvoidforce required to move level
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The patent implements continuous dynamic movement of the grate in the conveying direction, allowing clinker to move freely with the grate surface. This eliminates the need to push against a baffle plate, reducing required forces while preventing bulk material accumulation through continuous motion.

Inventive Principle:
Principle #15Dynamics

4Loss of energy

If cooling air flows through the bulk material bed without mixing, then heat recovery efficiency is reduced due to cold channels, but mixing increases wear on components

Engineering Contradiction:
Improveheat recovery efficiencyVSAvoidwear on cooler components
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The continuous movement of the grate creates dynamic conditions in the bulk material bed that promote natural mixing through motion-induced fluidization and convection currents. This dynamic mixing prevents cold channel formation and improves heat recovery efficiency without requiring additional mechanical mixing components that would be subject to wear.

Inventive Principle:
Principle #15Dynamics

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 design results in hotter exhaust air and reduced glowing clinker grains, improving heat recuperation efficiency and reducing wear on the cooler components.

Implementation Method 1

cooling gas flows through a bed of bulk material approximately transversely to the conveying direction and thereby absorbs the heat of the bulk material

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

cooling gas flows through the bed to enhance heat recovery

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2655994B2Method for cooling hot bulk material and cooler
Publication Date: 2022.11.30 KHD HUMBOLDT WEDAG GMBH
  • EP2655994B2 patent drawingFigure 1~3
  • EP2655994B2 patent drawingFigure 4~5.2
  • EP2655994B2 patent drawingFigure 6~7

AI summary

The invention relates to a cooler for cooling hot bulk material, wherein cooling gas flows approximately transverse to the feed direction through a bulk material bed, and absorbs the heat of the bulk material, wherein a fixture supporting the bulk material bed comprises a ventilation base through which the cooling gas flows, and wherein the feeding principle provides planks extending in the feed direction, wherein at least two adjacent planks are displaced in the feed direction at the same time and opposite the feed direction at different times. According to the invention, the planks comprise differently designed surfaces in the feed direction, on which the bulk material bed is supported, causing different average transport speeds due to the different frictional fits with the supported bulk material bed, so that the bulk material bed is thereby extended in the area of the faster feed and is compressed in the area of the slower feed. The fixture churns the bulk material to be cooled by means of vertical mixing, whereby the heat recuperation becomes more efficient.