Washing Machine Lint Filter Blockage Detection During Drying Cycle

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Solution Overview

Problem

Washing machines face reduced drying efficiency due to lint filter blockages, which impede air circulation between the tub and drying duct, necessitating a method to detect and clear blockages during the drying cycle.

Innovation Solution

A control unit calculates a filter blockage index based on temperature differences between the drying duct and tub, and the initial turning-on time of the drying heater, triggering the washing of the lint filter if the index exceeds a predetermined value, while reducing the rotation speed of the blowing fan and drum during the washing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lint filter is blocked by lint, then the air circulation between the tub and drying duct is impeded, but the drying efficiency is decreased

Engineering Contradiction:
Improveair circulationVSAvoiddrying efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control unit performs preliminary detection of lint filter blockage during the drying cycle by monitoring temperature differences and heater operation time. When blockage is detected, the system proactively initiates filter washing before the blockage severely impacts drying efficiency, thus maintaining reliable air circulation and productivity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the temperature difference between the drying duct and tub, along with the drying heater's operation time, to calculate a filter blockage index. This feedback mechanism allows the control unit to detect blockage conditions and trigger appropriate washing actions to maintain both air circulation reliability and drying efficiency

Inventive Principle:
Principle #23Feedback

2Productivity

If the drying heater operates for a long time to improve drying efficiency, then the energy consumption increases, but the temperature difference for detecting filter blockage becomes more pronounced

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

Solution Approach 1:

The system uses the temperature difference parameter and heater operation time as indicators to calculate a filter blockage index. By monitoring these parameter changes during the drying cycle, the system can detect filter blockage without requiring excessive energy consumption, thus balancing productivity and energy use

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the blowing fan operates at high speed to maintain air circulation, then the drying efficiency is improved, but the water injection effectiveness on the lint filter is reduced during washing

Engineering Contradiction:
Improveair circulationVSAvoidfilter washing effectiveness
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The control unit dynamically adjusts the blowing fan's rotation speed based on the operational phase. During normal drying, the fan operates at high speed to maintain air circulation reliability. During lint filter washing, the fan speed is reduced to enhance water injection effectiveness, allowing the system to adapt to different operational requirements

Inventive Principle:
Principle #15Dynamics

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 detects and addresses lint filter blockages, maintaining optimal air circulation and drying efficiency by automatically washing the filter when necessary, thereby preventing reduced performance.

Implementation Method 1

a drying cycle drying the laundry by heating the air inside of the tub and the drum

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a blowing fan suctioning air inside of the tub and the drum

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 3

a lint filter filtering foreign substance contained in the suctioned air

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 4

a washing water injection nozzle injecting the washing water to the lint filter

Methodology Applied
Scientific EffectFluid Spray: Fluid Spray

Data Source

PatentEP2868792B1Washing machine and control method thereof
Publication Date: 2019.07.24 SAMSUNG ELECTRONICS CO LTD
  • EP2868792B1 patent drawingFigure 1
  • EP2868792B1 patent drawingFigure 2
  • EP2868792B1 patent drawingFigure 3

AI summary

A washing machine includes a tub (20), a drum (30) rotatably installed at an inside of the tub (20), a drying unit (80) including a blowing fan (84b) suctioning air inside of the tub 820) and the drum (30), and a drying heater (82) heating the air inside of the tub and the drum, a lint filter (85b) filtering foreign substances contained in the suctioned air, and a control unit turning on/off the drying heater (82) and the blowing fan (84b) according to a temperature of a drying duct. If the drying heater (82) is turned off, the control unit determines whether the lint filter (85b) is blocked based on the temperature of the drying duct, the temperature of the tub (20) and the turning-on time of the drying heater (82), and washes the lint filter by determining whether the lint filter (85b) is blocked. The washing of the lint filter (85b) during the drying cycle allows the lint filter to be washed without performing a washing cycle, a rinsing cycle, or a spin cycle, and the air to be circulated between a drying duct and a tub.