Membrane Textile Drying Using Oscillating Vapor Pressure

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Solution Overview

Problem

Conventional drying methods for textiles with semi-permeable membranes, such as GoreTEX and Sympatex, are inefficient and time-consuming due to the inability of liquid water to penetrate these membranes, leading to incomplete drying and increased energy expenditure.

Innovation Solution

A method and device that utilize an air flow with oscillating partial pressure of water vapor, achieved through oscillating heating or condensation, to create a partial pressure gradient that drives water vapor through the semi-permeable membrane, allowing for quick and gentle drying by disrupting the flow equilibrium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional drying methods are used on textiles with semi-permeable membranes, then the drying process is simple and straightforward, but the drying efficiency is low and the process takes significantly more time

Engineering Contradiction:
Improvedrying efficiencyVSAvoiddrying time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies periodic oscillation of the air flow to create alternating wet and dry conditions on the textile surface. This periodic action disrupts the boundary layer and enhances mass transfer through the semi-permeable membrane, significantly improving drying efficiency while reducing drying time compared to conventional steady-state drying methods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the parameters of the air flow by oscillating its properties (such as velocity, temperature, or humidity) to create dynamic conditions that enhance water vapor transmission through the membrane. This parameter oscillation prevents equilibrium from being reached, maintaining a continuous driving force for moisture removal and thereby improving productivity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If high temperature is used to speed up drying, then drying speed increases, but the textile with semi-permeable membrane may be damaged or the membrane properties may deteriorate

Engineering Contradiction:
Improvedrying speedVSAvoidthermal damage to membrane
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The periodic oscillation of air flow parameters allows for intermittent high-temperature exposure followed by cooler periods, enabling efficient moisture removal while preventing continuous thermal stress on the membrane. This temporal variation in temperature exposure maintains drying speed without causing thermal damage.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent utilizes pneumatic oscillation of the air flow to enhance mass transfer and create favorable partial pressure gradients across the membrane. This pneumatic approach enables effective drying through fluid dynamics rather than relying solely on thermal energy, thereby reducing the need for high temperatures and preventing thermal damage to the membrane.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Productivity

If the air flow partial pressure of water vapor is kept constant, then the drying process is stable and easy to control, but the drying efficiency is reduced due to flow equilibrium forming at the membrane

Engineering Contradiction:
Improvedrying efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements periodic oscillation of the air flow partial pressure of water vapor to prevent equilibrium conditions at the membrane interface. This oscillation maintains a continuous concentration gradient that drives efficient moisture transmission through the membrane. The control system manages this oscillation through programmed variations in air flow parameters, achieving enhanced drying efficiency with manageable control complexity.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent transitions from static, constant air flow conditions to dynamic, oscillating conditions. By making the air flow parameters time-dependent and oscillating, the system maintains non-equilibrium conditions that maximize mass transfer driving force. This dynamic approach improves drying efficiency while the oscillation patterns are designed to be easily implementable and controllable.

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

The method enables rapid and moderate temperature drying of textiles with semi-permeable membranes by varying the partial pressure of water vapor, ensuring moisture is vaporized and passed through the membrane, overcoming the limitations of conventional drying processes.

Implementation Method 1

a partial pressure gradient is generated across the membrane which is sufficient to drive water vapor through the membrane

Methodology Applied
Scientific EffectPartial pressure gradient: Pressure Gradient

Implementation Method 2

a piece of textile with a semi-permeable membrane... a partial pressure gradient is generated across the membrane which is sufficient to drive water vapor through the membrane

Methodology Applied
Scientific EffectOsmosis: Osmosis

Implementation Method 3

a partial pressure of water vapor in the air flow is created by corresponding oscillating heating of the air flow

Methodology Applied
Scientific EffectOscillating heating: Heating

Implementation Method 4

a partial pressure of water vapor in the air flow is created by corresponding oscillating heating of the air flow or by oscillating condensation of moisture from the air flow

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

a piece of textile with a semi-permeable membrane... Because liquid water cannot penetrate such a functional membrane... a partial pressure gradient is generated across the membrane which is sufficient to drive water vapor through the membrane

Methodology Applied
Scientific EffectSemi-permeable membrane permeation: Semipermeable Membrane

Data Source

PatentEP1920103B1Method and apparatus for drying a piece of textile
Publication Date: 2018.10.31 BSH HAUSGERATE GMBH
  • EP1920103B1 patent drawingFigure 1~2
  • EP1920103B1 patent drawingFigure 3~4

AI summary

The invention relates to a method and an apparatus for drying a piece of textile (1) which is impinged upon by an air flow to evacuate moisture, a partial steam pressure in the air flow being varied. Said method and device are particularly suitable for drying a piece of textile (1) that is provided with a layered structure encompassing a semipermeable membrane (13).