Washing Machine Heated-Water Spin Method to Reduce Residual Moisture

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Solution Overview

Problem

Existing washing machine methods require a large amount of water and energy to achieve low residual moisture in laundry after the final spin phase, and they still leave a relatively high level of moisture in the laundry.

Innovation Solution

A method involving a control device that manages a washing machine program sequence, including pumping out free liquor, heating the laundry, and operating the drum at specific spin speeds to reduce moisture, with the option to refill and heat the water to a predetermined temperature for efficient water and energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the drum is operated at high spin speed to remove water from laundry, then residual moisture content is reduced, but water and energy consumption increases

Engineering Contradiction:
Improveresidual moisture contentVSAvoidwater consumption
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The heating device is activated before the spin phase to pre-heat the laundry and water in the tub. This preliminary heating reduces the water retention capacity of the laundry fibers, enabling more effective water removal during the subsequent spin phase at lower speeds, thus reducing both residual moisture and overall water consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the water and laundry during the rinsing phase. By heating the water to a predetermined temperature and maintaining it during the spin phase, the physical properties of water and the water retention capacity of laundry fibers are altered, improving water separation efficiency without requiring excessively high spin speeds or additional water.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the drum is operated at high spin speed to reduce residual moisture, then water removal efficiency is improved, but energy consumption increases

Engineering Contradiction:
Improveresidual moisture contentVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The heating device is activated before the spin phase to pre-heat the laundry and water in the tub. This preliminary heating reduces the water retention capacity of the laundry fibers, enabling more effective water removal during the subsequent spin phase at lower speeds, thus reducing both residual moisture and overall water consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the water and laundry during the rinsing phase. By heating the water to a predetermined temperature and maintaining it during the spin phase, the physical properties of water and the water retention capacity of laundry fibers are altered, improving water separation efficiency without requiring excessively high spin speeds or additional water.

Inventive Principle:
Principle #35Parameter changes

3Loss of time

If heated water is used in the final rinsing phase to increase tub temperature, then heat pump equilibrium is reached faster, but water and energy consumption increases

Engineering Contradiction:
Improvetime to reach equilibriumVSAvoidwater consumption
Core Design Contradiction:
Loss of timeVSQuantity of substance

Solution Approach 1:

The heating device uses the water already present in the tub during the rinsing phase, heating it to a predetermined temperature. This heated water then serves dual purposes: it speeds up the heat pump equilibrium process and simultaneously reduces the water retention capacity of the laundry for better spin performance. The system essentially uses its own resources (the rinsing water) to achieve multiple benefits without requiring additional water input.

Inventive Principle:
Principle #25Self-service

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 method reduces residual moisture in laundry while minimizing water and energy consumption, allowing for effective disinfection at lower temperatures and reducing mechanical stress on the laundry.

Implementation Method 1

a circulation pump for pumping water from a drain area of ​​the tub back into the tub via a circulation line

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 2

the water can be heated by the heater typically found in a washing machine, or by an additional hot water supply, or by a renewable energy source such as solar energy

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The centrifugal force pushes the water out of the laundry through the drum's drainage holes into a space between the drum and the tub

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

the initial heat exchange at the evaporator of the heat pump increases

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3004448B1Method for operating a washing machine achieving an improved residual moisture content of the laundry, and washing machine suitable therefor
Publication Date: 2017.07.12 BSH HAUSGERATE GMBH
  • EP3004448B1 patent drawingFigure 1
  • EP3004448B1 patent drawing

AI summary

The invention relates to a method for rinsing laundry (7) in a washing machine having a control device (12) for controlling a program sequence, a drum (2), which is rotatably mounted in a liquor container (1), a heating device (13), a pump (16) and a drive motor (14) for the drum (2), according to which method, in a rinsing phase having one or more rinsing steps following a washing phase, at least in the last rinsing step after the last portion of rinsing water is added to the liquor container (1) and the laundry (7) is rinsed through, (a) the pump (16) is switched on and a free detergent solution (6) situated in the liquor container (1) is pumped out; (b) the pump (16) is then switched off and the drum (2) is operated at a spin speed ω1 with the pump (16) switched off in order to reduce the moisture content of the damp laundry (7) from step (a) and to collect the water driven out in the process in the liquor container (1), such that for the quantity of water q in the liquor container, q = qcol; (c) if the quantity of water collected in step (b) is qcol < qset, the liquor container (1) is filled up with water from the water supply (8, 9) until q ≥ qset for the quantity of water q in the liquor container (1); (d) the quantity of water q in the liquor container (1) is heated to a predefined temperature Tset; (e) the heated water from step (d) is distributed in the laundry (7); and (f) the drum (2) is operated at a spin speed ω2 in order to drive heated water distributed in the laundry (7) from step (e) out of the laundry (7) and pump it away. The invention further relates to a washing machine suitable for carrying out the method.