Edge-Free Throwing Plate for Rotary Kiln Drying

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Solution Overview

Problem

Caking of asphalt material on the throwing plates in rotary kilns during the drying and heating process impedes material flow and leads to functional failure, as the edges of conventional throwing plates contribute to this issue.

Innovation Solution

The throwing plates are designed with an edge-free contour in a plane perpendicular to the material conveying direction, reducing the risk of caking and enabling targeted material transport, and the angle of inclination of these plates influences the pouring behavior to ensure even heat transfer and efficient material heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional throwing plates with edges are used, then material can be conveyed through the drying unit, but caking occurs on the throwing plates which impedes material flow and leads to functional failure

Engineering Contradiction:
Improvematerial flowVSAvoidfunctional failure
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The throwing plate is designed with a curved, edge-free contour in the plane perpendicular to the material conveying direction. This curvature eliminates sharp edges where material would otherwise accumulate and cake, allowing material to flow smoothly over the throwing plate surface without adhesion points, thereby maintaining both productivity and reliability

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If the throwing plate has an edge-free contour, then caking is reduced and eliminated, but the design complexity increases

Engineering Contradiction:
Improvecaking preventionVSAvoidthrowing plate design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The throwing plate employs a curved contour that is simple in form but effective in function. The curvature is achieved through a straightforward geometric design that eliminates edges without requiring complex multi-component structures, thus maintaining manufacturing simplicity while achieving reliable caking prevention

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Manufacturing precision

If the throwing plate angle of inclination is adjusted, then material pouring behavior is optimized for even heat transfer, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveheat transfer uniformityVSAvoidthrowing plate fabrication
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The angle of inclination of the throwing plate is optimized to a specific range (15-30 degrees) that naturally promotes even material distribution and heat transfer. This parameter optimization achieves manufacturing precision goals through a single geometric parameter that can be controlled within standard fabrication tolerances, avoiding the need for complex multi-parameter adjustments

Inventive Principle:
Principle #35Parameter changes

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 prevents caking, ensures reliable and trouble-free material heating, improves heat transfer efficiency, and maintains a consistent material veil within the drying unit, enhancing the overall efficiency of the material heating process.

Implementation Method 1

As a result of gravity, the material falls onto or into a subsequent throwing plate when the material has passed the end oriented in the material throwing plate conveying direction

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

A drying unit in the form of a rotary kiln is used, for example, in plants for the production of asphalt. A rotary kiln is known, for example, from GB 1 396 402 A, FR 871 651 A, FR 2 297 394 A1 or DE 26 26 625 A1. The rotary kiln is used to heat and mix used asphalt granules

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The rotary kiln is used to heat and mix used asphalt granules, so-called recycling (RC) material. During drying and heating, the material is conveyed through the drying unit, which rotates about a longitudinal axis. This will mix the material

Methodology Applied
Scientific EffectRotational motion:

Data Source

PatentEP3444549B1Drying unit comprising multiple such cast sheets
Publication Date: 2020.03.04 BENNINGHOVEN GMBH & CO KG MULHEIM
  • EP3444549B1 patent drawingFigure 1
  • EP3444549B1 patent drawingFigure 2
  • EP3444549B1 patent drawingFigure 3

AI summary

A throwing plate (27) for a drying unit (1) defines a material throwing plate conveying direction (39), wherein the throwing plate (27) has an edge-free contour in a plane oriented perpendicular to the material throwing plate conveying direction (39).