Dry-Cleaning Drum Air Circuit for Low Residual Solvent

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Solution Overview

Problem

Existing dry-cleaning machines using Methylenebis(oxy)dibutane solvent fail to reduce residual solvent concentration on garments to acceptable levels, resulting in strong odors after the cleaning cycle.

Innovation Solution

A dry-cleaning machine with a solvent distillation unit, filtration unit, and a control system that adjusts fan rotation speed based on solvent concentration, utilizing a closed air circulation circuit with an evaporator and condenser to condense and separate solvent vapors, ensuring low residual solvent levels on garments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a closed air circulation circuit with heating and cooling devices is used, then the drying function is provided, but the residual solvent concentration on garments cannot be reduced to acceptable levels

Engineering Contradiction:
Improvedrying functionVSAvoidresidual solvent concentration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies phase transition by cooling the air circulation circuit to below the dew point temperature, causing solvent vapor to condense from gaseous phase to liquid phase. This enables effective removal of residual solvent from garments by transforming the solvent vapor in the air into condensate that can be drained away.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent changes the temperature parameter of the air circulation circuit from standard drying temperatures to below the dew point temperature of the solvent. This parameter change transforms the cooling function into a condensation function, enabling the system to reduce residual solvent concentration to acceptable levels.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the drying cycle duration is extended to reduce solvent concentration, then residual solvent levels decrease, but the processing time increases

Engineering Contradiction:
Improveresidual solvent concentrationVSAvoiddrying cycle duration
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

By utilizing phase transition at the dew point, the system achieves rapid condensation of solvent vapor. This physical transformation process is much faster than gradual evaporation-based drying, enabling significant reduction in drying cycle duration while achieving low residual solvent concentrations.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent replaces the thermal drying mechanism (heating and gradual evaporation) with a condensation mechanism (cooling below dew point). This substitution changes the fundamental drying principle from time-intensive thermal processes to rapid phase-change condensation, dramatically reducing processing time.

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

3Ease of manufacture

If innovative solvents like Methylenebis(oxy)dibutane are used, then cleaning effectiveness and eco-friendliness improve, but strong odors are generated due to residual solvent

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidodor
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent uses phase transition (condensation) to remove solvent vapor from the air circulation system. By cooling the air below the dew point, solvent vapor condenses into liquid form and is drained away, effectively eliminating the source of odors while preserving the benefits of innovative solvent cleaning.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent converts the harmful effect of solvent vapor (odor) into a beneficial condensation process. The solvent vapor that causes odor is cooled below dew point, transforming it into liquid condensate that can be easily removed and reused, thereby eliminating odor while maintaining cleaning effectiveness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively reduces residual solvent concentration on garments to minimal levels, optimizing drying time and minimizing odors, while allowing for the reuse and purification of the solvent.

Implementation Method 1

means for heating the air

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

means for cooling the air

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

a closed circuit for circulating air for drying the articles

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

condense and separate solvent vapors

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2598685B1Machine and method for dry cleaning articles
Publication Date: 2014.07.02 F M B FAB MACCHINE BOLOGNA
  • EP2598685B1 patent drawingFigure 1
  • EP2598685B1 patent drawingFigure 2

AI summary

A dry cleaning machine (1) for articles (2) such as garments and the like, comprises: a rotary drum (4) for containing the articles (2); means (11) for feeding a solvent into the drum (4); means (16) for draining a solvent out of the drum (4); a closed circuit (37) for circulating air for drying the articles (2) inside the drum (4), comprising at least one air movement fan (17), means (18) for driving the fan (17), a heating device (36) for heating the air to be fed into the drum (4), an air cooling device (35) for condensing the solvent contained in the air flowing out of the drum (4).