Fluff Filter Washing Using Condensate in Closed-Loop Dryers

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Solution Overview

Problem

Existing laundry treatment apparatuses, such as dryers and washing machines, face inefficiencies in cleaning the fluff filter, leading to clogging and increased maintenance costs, as they often require separate condensate and washing liquid management systems that can introduce air pressure issues and require user intervention for filter cleaning.

Innovation Solution

A laundry treatment apparatus with a control unit, condensate collector, and fluff filter, where condensate is pumped to wash the fluff filter and collected washing liquid is directed to a separate collector, preventing air pressure differences and allowing for automated filter cleaning without user intervention, with a siphon or valve system to manage condensate flow and prevent contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If condensate and washing liquid are collected in the same container, then the system structure is simplified, but air pressure differences cause contamination and cleaning efficiency decreases

Engineering Contradiction:
Improvesystem structureVSAvoidcleaning efficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the liquid collection system into two separate containers: a condensate collector for collecting condensed water from the heat exchanger, and a washing liquid collector for collecting washing liquid that has washed the fluff filter. This segmentation prevents air pressure differences from causing contamination between the two liquid types, thereby maintaining cleaning efficiency while managing system complexity through functional separation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The washing liquid collector is extracted as a separate component from the condensate collection system. The washing liquid, which contains fluff particles removed from the filter, is directed to a dedicated collector through a separate conduit system, preventing it from contaminating the condensate and allowing independent management of each liquid stream.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If manual filter cleaning is required, then user intervention maintains control, but maintenance time and operational interruptions increase

Engineering Contradiction:
Improveuser controlVSAvoidmaintenance time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system implements automated fluff filter cleaning by using the collected condensate to wash the filter surface. A pump delivers condensate to a spray device that automatically cleans the fluff filter, and the resulting washing liquid is collected and drained. This self-service mechanism eliminates the need for manual user intervention, reducing maintenance time and operational interruptions while maintaining ease of operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary cleaning action by continuously or periodically washing the fluff filter with condensate before significant fluff accumulation occurs. This preventive cleaning approach maintains filter efficiency and reduces the frequency of intensive maintenance interventions required by users.

Inventive Principle:
Principle #10Preliminary action

3Loss of substance

If condensate is used to wash the fluff filter, then water resources are utilized efficiently, but condensate volume decreases affecting drainage capacity

Engineering Contradiction:
Improvewater resource efficiencyVSAvoidcondensate volume
Core Design Contradiction:
Loss of substanceVSQuantity of substance

Solution Approach 1:

The system recovers and reuses condensate by directing it to wash the fluff filter instead of draining it directly. The washing liquid, now containing fluff particles, is collected in a separate washing liquid collector and then drained. This approach efficiently utilizes water resources while the separate collection system ensures that the reduced condensate volume does not compromise drainage capacity, as the washing liquid is managed independently.

Inventive Principle:
Principle #34Discarding and recovering

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 solution ensures efficient fluff filter cleaning, reduces maintenance needs, and prevents air leaks, enhancing the operational efficiency and user experience by automating the cleaning process and maintaining a closed process air loop.

Implementation Method 1

The process air is cooled at a heat exchanger arranged in the process air circuit whereby humidity carried by the process air is condensed

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

a siphon is arranged in the conduit for draining the condensate from the condensate collector

Methodology Applied
Scientific EffectSiphon effect: Syphon

Data Source

PatentEP3090093B1Laundry treatment apparatus with fluff filter washing arrangement
Publication Date: 2018.12.19 ELECTROLUX APPLIANCES
  • EP3090093B1 patent drawingFigure 1
  • EP3090093B1 patent drawingFigure 2a~2b
  • EP3090093B1 patent drawingFigure 2c~3

AI summary

The invention relates to a laundry treatment apparatus (2), in particular dryer, condensate dryer, heat pump tumble dryer or washing machine having a dryer function, the apparatus (2) comprising: a control unit (16) for controlling the operation of the laundry treatment apparatus, an apparatus cabinet (3), a laundry treatment chamber (8) for treating laundry using process air (A), a process air circuit for circulating the process air (A), a heat exchanger (38) arranged in the process air circuit for cooling the process air (A) and condensing humidity from the process air, a condensate collector (32) assigned to the heat exchanger (38) for collecting condensate (C) condensed at the heat exchanger, a fluff filter (36) arranged in the process air circuit upstream the heat exchanger (38) for filtering fluff from the process air (A) passing the fluff filter, a washing liquid collector (34) assigned to the fluff filter (36) and being adapted to collect washing liquid (L) from the fluff filter, a condensate pump (52) in liquid connection to the condensate collector (32) and being adapted to convey the condensate (C), a condensate directing means (54) receiving the condensate (C) pumped by the condensate pump (52) and for selectively directing the condensate flow under the control of the control unit (16) a) to the fluff filter (36) for washing at least a portion of the filter surface by removing fluff, or b) to a condensate sink. According to the invention the fluff filter (36) and the washing liquid collector (34) are arranged such that the washing liquid (L) is flowing along at least a portion of the surface of the fluff filter (36) and is carrying fluff washed off from the surface into the washing liquid collector (34) which is adapted to collect the contaminated washing liquid (L).