Washing Water Recirculation Layout for Detergent Recovery

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Solution Overview

Problem

Existing washing machines with recirculation circuits face issues with imperfectly watertight valves, leading to undissolved detergent accumulating in the draining circuit, which reduces washing effectiveness and obstructs the draining pump, resulting in increased energy and detergent consumption.

Innovation Solution

A washing method that includes a valve between the tub and draining circuit, which shuts off during the heating phase to reduce energy consumption, and a recirculation circuit that collects undissolved detergent from the draining circuit and recirculates it back into the tub, enhancing washing efficiency and reducing detergent loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the valve is kept open to allow water circulation, then the washing machine can drain water effectively, but undissolved detergent accumulates in the draining circuit and obstructs the draining pump

Engineering Contradiction:
Improvedrainage efficiencyVSAvoiddetergent accumulation and pump obstruction
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The draining circuit is segmented into two zones by positioning the recirculation inlet downstream of the valve seat. This creates a separation where the valve controls water flow while the recirculation system independently manages detergent recovery from the lower circuit region, preventing detergent accumulation without obstructing drainage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The recirculation circuit acts as an intermediary system that retrieves undissolved detergent from the draining circuit and returns it to the tub. This mediator function prevents detergent from reaching the draining pump while maintaining effective water drainage through the valve.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a large amount of water is supplied to cover the laundry, then the laundry is thoroughly wetted, but the energy consumption for heating water increases

Engineering Contradiction:
Improvewashing effectivenessVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The recirculation circuit enables continuous reuse of washing water by pumping water from the lower portion of the tub and resupplying it to the upper portion. This continuous circulation allows thorough wetting of laundry with a reduced initial water volume, decreasing the energy required to heat large amounts of water while maintaining washing effectiveness.

Inventive Principle:
Principle #20Continuity of useful action

3Loss of substance

If the valve is positioned to allow recirculation inlet downstream, then undissolved detergent is recovered and recirculated, but the valve sealing must remain reliable under pressure variations

Engineering Contradiction:
Improvedetergent lossVSAvoidvalve sealing reliability
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The recirculation inlet is positioned downstream of the valve seat to capture undissolved detergent before it can be lost through the valve. This preliminary positioning ensures that even if the valve is not perfectly sealed, detergent accumulates in the lower draining circuit where the recirculation system can retrieve it and return it to the tub, preventing detergent loss.

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 method reduces energy consumption by minimizing water heating and detergent usage, while ensuring effective detergent utilization and maintaining washing effectiveness by recirculating undissolved detergent back into the tub.

Implementation Method 1

A valve (26) is arranged between the tub (2) and the draining circuit (16). The valve (26) is adapted to shut off the tub (2) from the draining circuit (16), in particular during a heating phase of a washing cycle

Methodology Applied
Scientific EffectValve sealing: Valve

Implementation Method 2

when the valve (26) is adapted to shut off the tub (2) from the draining circuit (16), in particular during a heating phase of a washing cycle of the washing machine. Due to the closed valve, water within the draining circuit is not heated, whereby the energy consumption of the washing machine is reduced

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

The washing machine comprises a recirculation circuit (10), which is fluidly connected to the tub (2) to circulate fluid from a lower portion of the tub to an upper or middle portion of the tub

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

At the beginning of a washing cycle, when a detergent like a powder detergent is not fully dissolved in the washing water, this detergent can accumulate at a lower portion of the tub due to gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2762632B1Washing method
Publication Date: 2016.09.14 ELECTROLUX HOME PROD CORP NV
  • EP2762632B1 patent drawingFigure 1~2
  • EP2762632B1 patent drawingFigure 3~4
  • EP2762632B1 patent drawingFigure 5~8

AI summary

The invention relates to a washing method for a washing machine (1) comprising: a tub (2), a draining circuit (16), wherein the draining circuit (16) is fluidly connected to a lower portion of the tub (2), a valve (26) arranged between the tub (2) and the draining circuit (16) and a recirculation circuit (10), comprising a recirculation pump (12), fluidly connected to the tub (2) for re-circulating fluid from the lower portion of the tub (2) into the tub (2), wherein an inlet (14) of the recirculation circuit (10) is positioned downstream said valve (26), said method comprising the step of heating washing water present in the tub, wherein during the heating of the washing water said recirculation pump (12) is stopped.