Low-Temperature Ozone Laundry Treatment for Damp Drum Disinfection

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Solution Overview

Problem

Existing methods for treating laundry at low temperatures are ineffective in reducing germs due to sluggish bleaching systems, and ozone use is limited by rapid decomposition and solubility issues, leading to inefficient germ reduction and potential environmental harm.

Innovation Solution

A method and washing machine design that introduces ozone-containing air at temperatures below 35°C to damp laundry without detergents, using a sensor to control ozone concentration and ensure efficient bleaching while minimizing ozone emission, with a rinse cycle to remove residues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If conventional bleaching systems are used at low temperatures, then energy consumption is reduced, but germ reduction effectiveness decreases

Engineering Contradiction:
Improveenergy consumptionVSAvoidgerm reduction effectiveness
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the bleaching system by using ozone instead of conventional bleaching agents. Ozone maintains high oxidizing power at low temperatures, enabling effective germ reduction without requiring high temperature operation, thus resolving the contradiction between energy consumption and disinfection effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs ozone, a strong oxidant, to accelerate the oxidation reactions necessary for germ reduction. This allows the bleaching process to be effective at low temperatures where conventional oxidants would be sluggish, thereby maintaining both low energy consumption and high disinfection effectiveness

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

2Reliability

If ozone is used for bleaching and disinfection, then germ reduction effectiveness improves, but ozone decomposition and solubility issues arise leading to inefficiency

Engineering Contradiction:
Improvegerm reduction effectivenessVSAvoidozone utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent uses a Venturi injector to introduce ozone into the wash liquid. The Venturi effect creates a pressure difference that efficiently mixes ozone gas with the liquid stream, improving ozone dissolution and utilization efficiency while maintaining effective germ reduction

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent introduces ozone into the wash liquid rather than applying it directly to laundry. The wash liquid acts as an intermediary medium that facilitates controlled ozone distribution and reaction, improving overall ozone utilization efficiency while maintaining disinfection effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If ozone is introduced into wash liquid using Venturi injector, then ozone mixing efficiency improves, but ozone loss through decomposition increases

Engineering Contradiction:
Improveozone mixing efficiencyVSAvoidozone decomposition loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent introduces ozone continuously during the washing process rather than in discrete batches. This continuous introduction maintains a steady-state ozone concentration in the wash liquid, allowing ozone to be efficiently utilized for germ reduction while minimizing losses through decomposition

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces ozone into the wash liquid before the main washing action occurs. This preliminary ozonation allows the wash liquid to become saturated with ozone at controlled rates, improving mixing efficiency while the subsequent washing process utilizes the ozone before significant decomposition can occur

Inventive Principle:
Principle #10Preliminary action

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 allows for effective bleaching and disinfection of laundry at low temperatures, reducing ozone consumption and environmental impact by ensuring ozone reacts predominantly on the laundry surface, preventing unwanted emissions and maintaining freshness.

Implementation Method 1

Ozone is one of the most effective oxidizing agents and is used on a large scale, e.g. in the paper industry, among other things as an efficient and environmentally friendly bleaching agent. Ozone is also used in commercial laundry care to bleach and disinfect textiles.

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

The washing machine has a sensor system with the aid of which the concentration c of detergent and/or auxiliary washing agent is measured.

Methodology Applied
Scientific EffectConductivity measurement: Conduction (electrical)

Data Source

PatentEP2580381B1Method for treating laundry in a washing machine at low temperature and washing machine suitable for said method
Publication Date: 2015.11.11 BSH HAUSGERATE GMBH
  • EP2580381B1 patent drawingFigure 1

AI summary

The invention relates to a method for treating laundry (7) in a washing machine, which comprises a suds container (1), a drum (2) rotatably supported in the suds container (1) for accommodating the laundry (7) to be treated with ozone, and a device (20) for providing ozone, wherein ozone-containing air at a temperature of no more than 35°C is introduced into the drum (2) onto washed laundry (7) that is in the drum (2) and that is still damp, while substantially no detergents or washing additives are in the drum (2), and wherein subsequently a rinsing process is carried out for the laundry (7) in the drum (2). The invention further relates to a washing machine that is especially suitable for said method.