Drying appliance that performs after-care cycle on a load of laundry after completion of a primary drying cycle and method for performing the after-care cycle

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Solution Overview

Problem

Laundry appliances fail to effectively maintain the freshness of laundry after a drying cycle, as residual moisture can lead to bacterial growth and odor, and existing methods do not adequately address this issue.

Innovation Solution

A method and system that includes an after-care cycle utilizing a heat pump system and blower to maintain residual fluid within the airflow path, with a drum temperature controlled within a predetermined range to kill bacteria and prevent odor, involving active and idle states of the compressor and blower operation, and a tumbling condition to ensure even air distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the drying cycle is completed and the appliance is deactivated, then energy consumption is reduced, but residual moisture remains in the laundry causing bacterial growth and odor

Engineering Contradiction:
Improvebacterial growth and odorVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The after-care cycle performs preliminary action by maintaining the drum temperature within a predetermined range (e.g., 50-70°C) for a specific duration after the drying cycle completes. This heat treatment kills bacteria and prevents odor before the appliance is fully deactivated, addressing the harmful factors in advance while minimizing energy consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The residual heat that would normally be wasted after the drying cycle is converted into a beneficial effect by maintaining the drum temperature for an extended period. This residual thermal energy is used to eliminate bacteria and prevent odor, transforming what would be a harmful residue into a useful protective function.

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

2Object-affected harmful factors

If the drum temperature is maintained at high levels continuously after drying, then bacterial growth is prevented, but energy consumption increases

Engineering Contradiction:
Improvebacterial growth preventionVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by stationary object

Solution Approach 1:

Instead of continuous high-temperature maintenance, the system uses periodic temperature maintenance within a predetermined range for a limited time period. The heat pump system operates intermittently to sustain the temperature, creating periodic heating cycles that are energy-efficient while still achieving bacterial elimination over time.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes the temperature parameter from high continuous heating to maintained temperature within a specific range (e.g., 50-70°C). This parameter optimization ensures sufficient heat for bacterial prevention while reducing energy consumption compared to continuous high-temperature operation.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If the heat pump system operates continuously to maintain temperature, then laundry freshness is preserved, but the after-care time period is extended unnecessarily

Engineering Contradiction:
Improvelaundry freshnessVSAvoidafter-care time period
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The heat pump system operates partially rather than continuously, providing sufficient heating only when the drum temperature drops below the predetermined range. This partial action maintains laundry freshness by preventing bacterial growth during critical periods while avoiding unnecessary operation when temperature is already sufficient, thus reducing the effective after-care time.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system uses feedback control by monitoring the drum temperature and activating the heat pump only when the temperature falls outside the predetermined range. This feedback mechanism ensures the after-care function is performed efficiently without extending the time period, as the system responds only when needed to maintain freshness.

Inventive Principle:
Principle #23Feedback

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

The after-care cycle effectively maintains freshness by controlling bacterial populations and preventing odor, allowing for extended storage of laundry without damage, reducing the need for additional fragrances and ensuring the laundry remains fresh for an extended period.

Implementation Method 1

A drum temperature is maintained within the drum at a predetermined temperature range during performance of the after-care cycle. A heat pump system is activated when the drum temperature reaches a lower limit of the predetermined temperature range

Methodology Applied
Scientific EffectHeat pump heating: Heat Exchanger

Implementation Method 2

A blower delivers the residual fluid to the drum. The blower delivers process air through an air flow path that includes the rotating drum and the heat exchanger

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 3

a heat exchanger. The compressor, the drum and the blower operate to perform a drying cycle and an after-care cycle

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3467185B1Drying appliance that performs after-care cycle on a load of laundry after completion of a primary drying cycle and method for performing the after-care cycle
Publication Date: 2020.06.10 WHIRLPOOL CORP
  • EP3467185B1 patent drawingFigure 1
  • EP3467185B1 patent drawingFigure 2
  • EP3467185B1 patent drawingFigure 3

AI summary

A method for processing laundry after completion of a drying cycle (12) includes maintaining residual fluid (52) within an airflow path (22) of the appliance (10), wherein the residual fluid (52) results from a primary drying cycle (12). A heat pump system (18) is activated and a blower (32) delivers the residual fluid (52) to the drum (16). A drum temperature (64) is maintained within the drum (16) at a predetermined temperature range (72) during performance of the after-care cycle (60).