High-Consistency Pulp Treatment Gap Control Using Vibration Detection

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Solution Overview

Problem

Existing devices for treating high-consistency fiber materials face challenges in efficiently determining the minimum distance between treatment tools to prevent damage and excessive wear while maintaining optimal treatment efficiency, which is complicated by the need for precise gap adjustments and costly sensor measurements.

Innovation Solution

The method involves monitoring vibrations during the relative rotation of treatment tools to determine the minimum distance by detecting a change in frequency or amplitude exceeding a limit value, setting this as the minimum distance, and adjusting the gap with a safety margin, allowing for continuous or incremental reduction of the distance during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the gap between treatment tools is reduced to increase treatment effectiveness, then the treatment efficiency is improved, but the risk of tool contact and damage increases

Engineering Contradiction:
Improvetreatment efficiencyVSAvoidtool damage risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent uses vibration sensors to detect the minimum distance between treatment tools during rotation. By monitoring vibration changes, the system can determine when tools are approaching contact without actually touching, allowing the gap to be optimized for maximum treatment efficiency while preventing tool damage through early warning detection.

Inventive Principle:
Principle #18Mechanical vibration

2Measurement precision

If expensive sensors are used to measure current gap width accurately, then the measurement precision is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvegap width measurementVSAvoidsensor cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces expensive direct gap measurement sensors with vibration sensors that indirectly detect gap conditions. The vibration pattern serves as a copy or indicator of the actual gap state, providing sufficient measurement precision for operational control without the complexity and cost of direct measurement instruments.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent substitutes mechanical or electronic gap measurement systems with a vibration-based detection system. By using vibration frequency and amplitude changes as proxies for gap width, the system achieves the necessary measurement precision while avoiding complex measurement hardware.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the treatment tools are set to touch at zero point to maximize treatment intensity, then the treatment effectiveness is improved, but the electrical current consumption and wear increase excessively

Engineering Contradiction:
Improvetreatment effectivenessVSAvoidelectrical current consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback system using vibration sensors to continuously monitor the gap between treatment tools during operation. When vibration indicators suggest the tools are approaching contact, the system automatically adjusts the gap to prevent excessive current consumption and wear, maintaining optimal treatment effectiveness without dangerous operating conditions.

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

This approach enables safe, efficient, and simple determination of the minimum distance between treatment tools, minimizing downtime and preventing damage, while ensuring optimal treatment performance by adjusting the gap based on operational parameters.

Implementation Method 1

the vibrations of the device, in particular at least one element thereof, are recorded and the distance between the base plates rotating relative to one another is reduced until the frequency and/or the amplitude and/or the change in the frequency and/or the change in the amplitude of the vibrations exceeds a limit value

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3914768B1Method for controlling a device for treating high-consistency pulp
Publication Date: 2025.08.06 VOITH PATENT GMBH
  • EP3914768B1 patent drawingFigure 1~3

AI summary

The invention relates to a method for controlling a device for processing high-consistency fibrous material (1), comprising a housing (2), in which a first treatment tool (3) and a second treatment tool (4) are arranged, wherein in each case the treatment tools (3, 4) are fastened to a base plate (7, 8), have a rotationally symmetrical form, are arranged coaxially to each other, rotate relative to one another about a common axis (5) and delimit a treatment gap (6) through which the fibrous material (1) radially flows, the gap width of which gap can be varied by axially shifting at least one base plate (7, 8) of a treatment tool (3, 4). The aim of the invention is to provide safe and efficient operation of the device using relatively simple means, in that, in order to determine the minimum distance (SM) between the base plates (7, 8), the oscillations are detected on the device and in that the distance (s) between the base plates (7, 8) rotating relative to one another is reduced until the frequency (f) and/or the amplitude and/or the change in frequency (Äf) and/or the change in amplitude of the oscillations exceeds a limit value and the distance (s) when the limit value is exceeded is determined as the minimum distance (SM).