Washer Recirculation Control for Low-Water Load Wetting

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Solution Overview

Problem

Washing machines face challenges in reducing water and energy consumption while maintaining washability and preventing wear on laundry, especially with proposed regulatory standards that limit water use, affecting the ability to properly wet and agitate large loads.

Innovation Solution

A recirculation system in the washing machine that removes and returns wash liquid from the tub to the basket, controlled by a system that initiates recirculation during specific phases of the wash cycle, including an initial fill and final fill, to maintain optimal liquid levels and facilitate agitation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If large loads are filled with almost 22 gallons of water to ensure proper wetting and agitation, then washability is improved, but water consumption and energy use increase beyond regulatory limits

Engineering Contradiction:

ImprovewashabilityVSAvoidwater consumption

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The system wets the laundry load in advance during a slow basket spin with an initial fill of wash liquid before the main wash cycle begins. This preliminary wetting action ensures that laundry items are adequately saturated with detergent solution, maintaining washability while reducing the total water volume needed during subsequent agitation phases.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A recirculation pump system hydraulically circulates concentrated wash liquid from the tub bottom through spray nozzles back onto the laundry load. This hydraulic recirculation mechanism distributes detergent solution efficiently throughout the load, ensuring proper wetting and agitation with significantly reduced water consumption compared to traditional fill methods.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Quantity of substance

If water volume is reduced to meet regulatory standards, then water and energy consumption decrease, but the ability to properly wet and agitate large loads is compromised

Engineering Contradiction:

Improvewater consumptionVSAvoidwashability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The system concentrates detergent solution locally on the laundry load through targeted spray nozzles that deliver recirculated wash liquid directly onto the garments. This localized concentration of cleaning agents ensures effective wetting and agitation of large loads while using minimal water volume, addressing regulatory requirements without sacrificing washability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The recirculation pump operates continuously throughout the wash cycle, constantly circulating and redistributing concentrated wash liquid over the laundry load. This continuous action ensures sustained wetting and agitation effectiveness despite reduced water volume, maintaining reliable washing performance throughout the entire cycle.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If recirculation rate is increased to improve liquid distribution, then wetting effectiveness is improved, but energy consumption increases

Engineering Contradiction:

Improvewetting effectivenessVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The recirculation pump operates in periodic cycles rather than continuously at maximum capacity. The system alternates between recirculation phases and idle phases, delivering concentrated wash liquid in periodic bursts that effectively redistribute moisture throughout the load. This periodic operation maintains wetting effectiveness while significantly reducing average energy consumption compared to continuous high-rate recirculation.

Inventive Principle:

Principle #19Periodic 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 reduces water consumption and energy use while ensuring effective wetting and agitation of laundry loads, even with larger loads, by optimizing liquid distribution and flow rates within the machine.

Implementation Method 1

a pump assembly pumps water from the tub to a drain

Methodology Applied

Scientific EffectPump: Pump

Implementation Method 2

A drive and motor assembly is mounted underneath the stationary outer tub to rotate the basket and the agitator relative to one another

Methodology Applied

Scientific EffectGravity: Gravitation

Implementation Method 3

a recirculation system coupled between the tub and the basket and is configured to remove wash liquid from the tub and return wash liquid to the basket

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS7703306B2Clothes washer recirculation systems and methods

Publication Date: 2010.04.27 HAIER US APPLIANCE SOLUTIONS INC

AI summary

A washing machine is provided that includes a tub and a perforated basket rotationally mounted within the tub for relative rotation therewith. A recirculation system is coupled between the tub and the basket and is configured to remove wash liquid from the tub and return wash liquid to the basket. A controller is operatively coupled to the washing machine. The controller is configured to begin recirculation of concentrated wash liquid after an initial fill during a basket slow spin and continue the recirculation of concentrated wash liquid for a predetermined time period prior to a complete fill.