Induction-Heated Laundry Drum Drying With Dual Overheat Cutoff

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing laundry treating apparatuses face challenges in accurately detecting dryness due to sensor contamination by detergents, washing water, or lint, and require complex temperature sensor setups for effective drying control, especially when using induction heaters, which lack specific safety measures for abnormal overheating scenarios.

Innovation Solution

A laundry treating apparatus with a dual-sensor system for temperature monitoring, where a first safety device on a low-current control wire interrupts the induction heater's operation based on temperature thresholds, and a second safety device autonomously cuts off power in abnormal conditions, ensuring reliable operation and safety without direct sensor contact with the drying target, and utilizing a separate safety device to prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a humidity sensor is used to detect dryness, then drying end time can be detected, but the sensor is contaminated by detergent, washing-water or lint making it difficult to sense accurate humidity

Engineering Contradiction:
Improvehumidity detection accuracyVSAvoidsensor reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent removes the humidity sensor from the drying chamber environment where it would be contaminated by detergent, washing-water, and lint. Instead, the system uses temperature sensors positioned in the air stream to indirectly detect drying progress, extracting the sensing function from the contaminated zone to a clean zone.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces air temperature as an intermediary parameter to detect drying progress. Rather than directly measuring humidity with a contaminated sensor, the system measures air temperature changes caused by moisture evaporation and condensation, using temperature as a mediator to infer drying status without direct contact with contaminants.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If temperature sensors are installed near inlet and outlet of condensing duct to determine dryness, then drying end time can be determined, but the apparatus requires complex circulation duct and multiple temperature sensors increasing manufacturing complexity

Engineering Contradiction:
Improvedrying detection accuracyVSAvoidsensor installation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the temperature sensing function with existing air circulation components. The temperature sensors are integrated into the air stream path within the drying chamber, merging the measurement function with the existing airflow structure rather than requiring separate sensing ducts and multiple sensors at duct inlet and outlet.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The temperature sensors serve multiple functions: they monitor air temperature for drying detection, track thermal conditions for safety, and provide data for controlling the induction heater. This multi-functionality reduces the need for specialized sensors and simplifies the overall system architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If induction heater is used to heat drum, then drying efficiency is improved, but safety measures are needed to prevent overheating in abnormal conditions

Engineering Contradiction:
Improvedrying efficiencyVSAvoidoverheating risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary safety measures by positioning temperature sensors to detect abnormal temperature rises before they lead to dangerous overheating conditions. The system continuously monitors thermal conditions and can preemptively adjust or shut down the induction heater to prevent harmful overheating scenarios.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent establishes a feedback control system where temperature sensors continuously monitor the thermal state of the drum and air, and this information feeds back to control the induction heater operation. The system adjusts heating power based on real-time temperature feedback, maintaining efficient drying while preventing dangerous overheating through continuous monitoring and adjustment.

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

This solution effectively determines accurate drying timing and prevents safety accidents by reducing sensor malfunction risks and ensuring safe operation even in abnormal conditions, enhancing the reliability and efficiency of the laundry treating process.

Implementation Method 1

an induction heater disposed on the tub and configured to heat an outer circumferential face of the drum contacting the heater

Methodology Applied
Scientific EffectInduction heating: Induction Heating

Data Source

PatentEP3680382B1Laundry treating apparatus having induction heater
Publication Date: 2023.05.10 LG ELECTRONICS INC
  • EP3680382B1 patent drawingFigure 1
  • EP3680382B1 patent drawingFigure 2
  • EP3680382B1 patent drawingFigure 3

AI summary

Disclosed is a laundry treating apparatus for heating a drum using an induction heater. The laundry treating apparatus includes a tub (2); a drum (3) rotatably disposed within the tub (2) and for accommodating an object therein; an induction heater (8) disposed on the tub (2) and configured to heat an outer circumferential face of the drum (3) contacting the induction heater (8); a motor (6) to rotate the drum (3); a power supply (210) for supplying power from an external power source to the laundry treating apparatus; a relay (410) configured to interrupt current to be applied from the power supply (210) to the induction heater (8) via an electrical wire (w1), wherein the relay (410) has a normal open type; a processor (9) connected to the relay (410) via a control wire and configured to control an operation of the relay (410) and to control an operation of the induction heater (8) and an operation of the motor (6); and a first safety device disposed at the control wire to interrupt a control signal to be applied from the processor (9) to the relay (410), wherein the first safety device operates in response to a temperature change thereof.