Vertical Roller Mill Scraper Dynamics for Stable Grinding

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Solution Overview

Problem

Conventional vertical roller mills experience operational inefficiencies due to the need for frequent stoppages to adjust the scraper height in response to fluctuations in material layer thickness, leading to vibrations and unstable grinding processes.

Innovation Solution

A vertically adjustable scraper system with a mobilizing mechanism allowing the scraper to swing and adjust its height automatically in response to changing layer thickness, incorporating a weight for resistance and adjustable range limits, ensuring optimal contact with the material and minimizing vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed scraper is used to uniformize layer thickness, then mill vibration is reduced, but operation efficiency declines due to frequent stoppages for height adjustment

Engineering Contradiction:
Improvestable operationVSAvoidoperation efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The scraper is designed with a movable support member that can dynamically adjust its position vertically. The support member includes a movable body that swings about a horizontal axis, allowing the scraper to automatically adapt to changing layer thickness during operation without requiring stoppages for manual adjustment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The scraper system uses the material layer itself to drive the adjustment mechanism. When the layer thickness increases, the material pushes the scraper upward, automatically adjusting the scraper height to match the new layer thickness without external intervention or system stoppage.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If scraper height is manually adjusted to match layer thickness, then grinding stability is improved, but time loss occurs during adjustment operations

Engineering Contradiction:
Improvelayer thickness uniformityVSAvoidadjustment time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The scraper is pre-configured with a movable support structure that is ready to adjust automatically when layer thickness changes occur. The mobilizing means and resistance adding means are pre-installed to enable immediate response to layer thickness variations without requiring manual intervention.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The scraper system provides automatic feedback-based adjustment where changes in layer thickness directly cause corresponding adjustments in scraper position. The movable support member responds to the physical state of the material layer, creating a self-regulating system that maintains optimal layer thickness uniformity continuously.

Inventive Principle:
Principle #23Feedback

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

The system enables continuous operation by automatically adjusting the scraper height, reducing mill vibrations and enhancing grinding efficiency through deaeration and consolidation of the material, thereby stabilizing the grinding process.

Implementation Method 1

incorporating a weight for resistance and adjustable range limits

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

A vertically adjustable scraper system with a mobilizing mechanism allowing the scraper to swing and adjust its height automatically

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP3238824B1Vertical roller mill
Publication Date: 2019.11.13 KAWASAKI JUKOGYO KK
  • EP3238824B1 patent drawingFigure 1
  • EP3238824B1 patent drawingFigure 2
  • EP3238824B1 patent drawingFigure 3

AI summary

This vertical roller mill is provided with: a rotary table having a grinding surface; a grinding roller (3) for biting and grinding a material between the grinding surface and the same; and a scraper (13) for adjusting a layer thickness of the material supplied to the grinding roller (3). The scraper (13) has: a scraper body (15) separately arranged above the grinding surface of the rotary table; a mobilizing means (16) for allowing the scraper body (15) to move in a direction away from the grinding surface; and a resistance adding means (17) for adding a resistance force to the movement of the scraper body (15) in the direction away from the grinding surface. Even when the layer thickness of the material supplied onto the grinding surface of the rotary table fluctuates, a height position of the scraper is automatically adjusted according to the fluctuation in layer thickness.