Dryer Filter Airflow Reversal for Automatic Lint Clog Clearing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional clothes treatment apparatuses, such as combined drying and washing machines, face challenges in reducing treatment time and electric power consumption, and require frequent maintenance due to lint accumulation, which can lead to efficiency losses and potential failures in the blower and heater systems.

Innovation Solution

A control method that reverses the air flow direction through the filter to clear lint clogs, using pressure and temperature sensors to detect clogging and adjust the blower fan's rotation direction or utilize a bypass to redirect air flow, thereby facilitating easy maintenance and reducing treatment time and energy usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter is installed to remove lint from hot air, then lint accumulation in the condensing duct and blower is reduced, but the filter itself becomes clogged and requires maintenance

Engineering Contradiction:
Improveblower reliabilityVSAvoidfilter maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system automatically cleans the filter by reversing airflow through it using the blower motor, eliminating the need for manual intervention. The control unit detects filter clogging and autonomously initiates the reverse airflow cleaning process, allowing the filter to self-maintain during dryer operation.

Inventive Principle:
Principle #25Self-service

2Productivity

If the blower motor runs continuously at high speed to maintain drying efficiency, then drying speed is improved, but energy consumption increases

Engineering Contradiction:
Improvedrying speedVSAvoidblower energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The blower motor operates in alternating cycles of forward and reverse directions. During forward operation, it performs the primary drying function; during reverse operation, it cleans the filter. This periodic reversal maintains filter efficiency without requiring continuous high-speed operation, reducing overall energy consumption while sustaining drying productivity.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes the operational parameters of the blower motor by reversing its rotation direction. This parameter change allows the same motor to perform two functions: forward rotation for drying and reverse rotation for filter cleaning, optimizing energy usage across different operational phases.

Inventive Principle:
Principle #35Parameter changes

3Ease of repair

If the filter is cleaned manually by disassembling the dryer, then filter maintenance is achieved, but treatment time is lost and complexity increases

Engineering Contradiction:
Improvefilter cleaning easeVSAvoiddowntime during maintenance
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The filter cleaning function is integrated into the normal drying operation. The control unit automatically detects when filter cleaning is needed and initiates reverse airflow through the filter without requiring user intervention or dryer shutdown. This eliminates maintenance downtime and simplifies the cleaning process to an automated function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The dryer maintains continuous operation during filter cleaning by switching the blower to reverse mode while the drum continues rotating. This allows filter maintenance to occur without interrupting the drying cycle, eliminating downtime and maintaining productive action throughout the process.

Inventive Principle:
Principle #20Continuity of useful action

4Device complexity

If lint is not removed from the condensing duct, then device complexity is reduced, but condensing efficiency decreases and harmful factors increase

Engineering Contradiction:
Improveduct system simplicityVSAvoidcondensing efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The system converts the harmful accumulation of lint in the condensing duct into a beneficial cleaning process. By reversing the blower airflow, the system actively removes lint from the condensing duct and filter, transforming what would be a harmful accumulation into a controlled cleaning operation that maintains condensing efficiency without adding complex mechanical cleaning mechanisms.

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

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 effectively reduces treatment time and energy consumption while simplifying filter maintenance by automatically detecting and addressing lint clogs, ensuring efficient operation and extending the lifespan of the apparatus.

Implementation Method 1

a blower fan that blows air having passed through the filter in a first direction, wherein air flow passing through the filter in the second direction opposite to the first direction is fed

Methodology Applied
Scientific EffectAir flow reversal:

Implementation Method 2

a filter that removes lint from air passing through the filter

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 3

a pair of pressure sensors that are arranged respectively at left and right sides of the drying duct between one end and the other end of the drying duct... sensing means for sensing clogging of the filter... measures a pressure differential between front and rear sides of the filter

Methodology Applied
Scientific EffectPressure differential measurement: Pressure Drop

Implementation Method 4

a heater that heats air in the drying duct

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2581490B1Clothes treatment apparatus and control method thereof
Publication Date: 2018.04.04 LG ELECTRONICS INC
  • EP2581490B1 patent drawingFigure 1
  • EP2581490B1 patent drawingFigure 2
  • EP2581490B1 patent drawingFigure 3~4

AI summary

A control method of a clothes treatment apparatus is disclosed, the clothes treatment apparatus having a drying duct (1210), a first blower fan (1230) located in the drying duct (1210) to enable circulation of interior air of the drying duct (1210) and a filter (1250) located in the drying duct (1210), wherein the method includes the steps of sensing clogging of the filter (1250); and switching a flow of air passing through the filter (1250) from a first direction to an opposite second direction if clogging of the filter is sensed. Moreover, the control method may include a washing cycle (200) for washing clothes, and a drying cycle (300) for drying the clothes. The implementation time of the washing cycle (200) is less than the implementation time of the drying cycle (300).