Laundry Dryer Filter Belt Layout to Prevent Lint Re-Entrapment

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Solution Overview

Problem

Existing dryer filter systems are susceptible to lint contamination, as lint not caught by the wiper can be transported into areas where the cleaned air flow exits, potentially re-entering the air stream and causing further contamination in the heat exchanger.

Innovation Solution

A filter device with a revolving belt and rollers directs the air flow through an interior space, using an opening transverse to the rollers' axes, ensuring the filtered air exits perpendicular to its entry, preventing lint from re-entering the air stream during cleaning and reducing contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter element is designed as a revolving belt with the entire belt containing filter material, then the filter effect is improved, but lint collects in the interior of the filter device and becomes difficult to remove

Engineering Contradiction:
Improvefilter effectVSAvoidlint removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The filter belt is divided into a front filtering section and a rear non-filtering section. The front section contains filter material for capturing lint, while the rear section is designed with a large mesh or open structure that does not develop filter effect. This segmentation allows lint to be collected on the front section while preventing accumulation in the interior space, facilitating easier removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the filter belt are assigned different functional properties. The front section has fine mesh filter material for effective lint capture, while the rear section has a large mesh structure that allows air passage without filtering. This local differentiation optimizes both filtration performance and maintenance ease.

Inventive Principle:
Principle #3Local quality

2Extent of automation

If the filter element is cleaned by driving the rollers to rewind the belt, then the cleaning process is automated, but lint not caught by the wiper is transported into the air flow exit area and can re-enter the air stream

Engineering Contradiction:
Improvecleaning automationVSAvoidlint re-contamination
Core Design Contradiction:
Extent of automationVSObject-affected harmful factors

Solution Approach 1:

The harmful function of the rear belt section is extracted by designing it with a large mesh structure that does not capture lint. This ensures that lint not removed by the wiper remains on the front section and is not transported into the air flow exit area during rewinding, preventing re-contamination of the cleaned air.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The rear section of the filter belt is pre-designed with a large mesh structure that prevents filter effect development. This preliminary design feature counteracts the potential harmful effect of lint being transported during belt rewinding, as the rear section does not adhere lint that could later be deposited into the air stream.

Inventive Principle:
Principle #9Preliminary anti-action

3Object-generated harmful factors

If the rear section of the filter element is designed with a large mesh to prevent filter effect, then lint transport is reduced, but the overall filtration capability may be compromised

Engineering Contradiction:
Improvelint transportVSAvoidfiltration capability
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The filter belt is segmented into front and rear sections with different mesh sizes. The front section maintains fine mesh for effective filtration, while the rear section uses large mesh to prevent lint transport during rewinding. This segmentation preserves overall filtration capability while reducing harmful lint transport.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter element exhibits local quality variations along its length. The front portion provides high filtration capability with fine mesh, while the rear portion has reduced filtration capability with large mesh. This local differentiation optimizes the balance between filtration performance and prevention of lint re-contamination.

Inventive Principle:
Principle #3Local quality

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 design prevents lint from being redeposited into the air flow, maintaining cleaner filter surfaces and reducing lint transport to areas where it can re-contaminate the heat exchanger, enhancing maintenance efficiency and reducing lint-related issues.

Implementation Method 1

an air filter element, also known as a fluff filter, is typically arranged between the drying room and the heat exchanger for separating particles from the air flow in general and textile fluff in particular

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

the front section of the filter element is guided past a scraper for cleaning by driving the rollers

Methodology Applied
Scientific EffectMechanical cleaning through friction: Friction

Implementation Method 3

a belt-shaped filter element in the form of a revolving belt is stretched over two rollers

Methodology Applied
Scientific EffectMechanical rotation: Roller

Data Source

PatentEP2248939B1Household appliance, in particular laundry dryer
Publication Date: 2012.06.20 V-ZUG AG
  • EP2248939B1 patent drawingFigure 1~3
  • EP2248939B1 patent drawingFigure 4~5
  • EP2248939B1 patent drawingFigure 6

AI summary

The appliance has a filter device (3) comprising a filter element (31) that is supported on rollers (35) and designed as a circulating strip. The filter element separates particles from air flow, and an inner area (30) is defined by the strip and the rollers, where the filter element is designed as a dust filter. A cleaning device i.e. wiper (32), cleans the filter element, and a support (361) is provided for conducting the air flow along a path that runs through the filter element and through an opening of the inner area, where the opening is extended transverse to axes (351) of the rollers.