Textile Dryer Residual Moisture Control via Exhaust Air Analysis

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Solution Overview

Problem

Existing dryers for textile webs face challenges in achieving uniform drying with minimal energy input, particularly for non-natural fibers like spunbond and continuous filaments, where accurate measurement of residual moisture is difficult due to their inability to absorb moisture, leading to inaccurate and costly measurement methods.

Innovation Solution

A control system that determines residual moisture by calculating the mass balance of moisture using sensors for exhaust air temperature, volume flow, and humidity, allowing for regulation of evaporation performance and energy adjustment to achieve a specified residual moisture without interrupting the continuous process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radiometric measurement devices are used to measure residual moisture content, then measurement precision is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improveresidual moisture content measurementVSAvoidmeasurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses air humidity as an intermediary parameter to indirectly determine web moisture content. Instead of measuring the web directly, the system measures the humidity of air passing through the web, which carries information about moisture transfer. This intermediary measurement approach simplifies the measurement system while maintaining accuracy for non-absorbing materials like spunbond.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex radiometric measurement systems with a simpler air humidity sensing system. By substituting direct web measurement (radiometric) with indirect air phase measurement (humidity sensing), the system achieves comparable measurement precision with significantly reduced device complexity and cost.

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

2Productivity

If heating power and fan performance are increased to improve drying performance, then productivity is improved, but energy consumption increases

Engineering Contradiction:
Improvedrying performanceVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback control system where air humidity measurements are continuously monitored and used to adjust heating power and fan performance. The control system modifies operating parameters based on actual moisture removal rates, ensuring optimal drying performance while minimizing energy consumption by avoiding excessive heating or air movement when moisture content is already low.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic adjustment of heating power and fan performance based on real-time moisture conditions. Instead of operating at fixed high power levels, the system dynamically adapts its parameters to match the actual drying needs, allowing productivity to be optimized while energy consumption is kept minimal throughout the drying process.

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 approach enables precise and cost-effective determination of residual moisture, minimizing energy consumption and eliminating the need for expensive radiometric measurements, making it suitable for low-weight fibers with low moisture levels.

Implementation Method 1

at least one sensor (18, 19, 20) for determining the temperature, air volume and humidity of the exhaust air (13)

Methodology Applied
Scientific EffectHumidity sensing: Hygrometer

Implementation Method 2

Heating elements located in the heating and fan chamber provide the heat required to heat the drying air

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

at least one fan (17) for sucking out the moist drying air from the inside of the drum (3)

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 4

Heated drying air flows through the web, absorbing the moisture from the web

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3601916B1Dryer for a textile cloth web with a system for determining the residual humidity of a cloth web and method and installation hereto
Publication Date: 2024.02.07 TRUETZSCHLER GRP SE
  • EP3601916B1 patent drawingFigure 1
  • EP3601916B1 patent drawingFigure 2
  • EP3601916B1 patent drawingFigure 3

AI summary

The invention relates to a dryer (1) for a textile material web (5) having at least one dryer chamber (2), in which at least one air-permeable drum (3-3c) is rotatably arranged, which can be entwined at least in part by the material web (5) and wherein heated drying air can flow through the material web (5), and wherein there is at least one ventilator (17) by means of which moist drying air can be suctioned from the inside of the drum (3-3c) from an opening in the end face of the at least one drum (3-3c) and discharged by means of a duct (14) as exhaust (13). The dryer (1) has at least one sensor for determining the moisture of the exhaust flow, the data of which is processed in a controller (30) together with the starting moisture of the material web (5) and the moisture of the fresh air flow and the evaporating power of the dryer (1) is thus regulated. The invention further relates to a method, to a module, and to a system for determining the residual moisture of a material web continuously running through a dryer.