Washer-Dryer Duct Sensor Placement for Reliable Humidity Detection

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Solution Overview

Problem

Existing washer-dryers face reduced performance in detecting humidity variations during the drying cycle due to sensor limitations, affecting the automatic control system's efficiency.

Innovation Solution

A washer-dryer design featuring a duct in the rear wall of the washing tub, fluidly connected to the condenser inlet, with sensors placed inside the duct to detect air stream parameters, and a partition wall to protect against water drops, ensuring effective detection of air temperature and humidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the sensor is placed in the air stream flowing through the drying cycle, then the automatic control system can detect humidity variations, but the sensor performance is reduced when it cannot detect variations of the parameter

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

Solution Approach 1:

A duct is introduced as an intermediary structure between the air stream and the sensor. The duct guides the air stream to flow directly over the sensor surface, ensuring the sensor is exposed to the moisture-laden air without being directly in the main flow path. This intermediary structure resolves the contradiction by enabling reliable humidity detection while protecting the sensor from direct exposure to harsh drying conditions that could reduce its reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the sensor is placed directly in the air stream, then humidity detection is possible, but the sensor may be affected by water drops and noise

Engineering Contradiction:
Improveair stream parameter detectionVSAvoidwater drop interference and noise
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The duct serves as a protective intermediary that channels the air stream around the sensor rather than allowing direct contact. The sensor is positioned within the duct structure, exposing it to the moisture-laden air for accurate detection while the duct walls shield it from harmful water drops and reduce noise interference from the main air flow.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the condenser and rear wall are formed as separate parts, then manufacturing flexibility is maintained, but the structure becomes more complex

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidstructural complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The condenser and rear wall are merged into a single integrated component. The rear wall is designed with an integrated duct structure that incorporates the condenser inlet and sensor housing. This merging eliminates the need for separate assembly of multiple parts, reducing structural complexity while maintaining manufacturing feasibility through integrated forming processes.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration ensures reliable detection of air stream parameters, improving performance by directing the entire air stream through the sensor before condensation, enhancing humidity determination and reducing noise and drying time.

Implementation Method 1

at least one condenser for condensing the moisture-laden air exiting the laundry during the drying cycle

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3492645B1A washer-dryer with at least one condenser
Publication Date: 2020.09.16 ELECTROLUX HOME PROD CORP NV
  • EP3492645B1 patent drawingFigure 1
  • EP3492645B1 patent drawingFigure 2
  • EP3492645B1 patent drawingFigure 3

AI summary

The present invention relates to a washer-dryer with at least one condenser for condensing moisture-laden air exiting the laundry during a drying cycle. The washer-dryer comprises a washing tub (10) comprising a cylindrical lateral wall (12) and a rear wall (14); a rotatable laundry drum (24) arranged or arrangeable inside the washing tub (10). An inlet (20) of the condenser is arranged at or connected to the rear wall of the washing tub (10); an outlet of the condenser is connected to the washing tub (10). The washer-dryer is characterised by a duct in the rear wall (14) of the washing tub (10) formed by an embossed area or by a hollow or sunken area, the duct (18) fluidly connected to the inlet (20) of the condenser, so that the air stream from the laundry drum (24) to the inlet (20) of the condenser passes the duct (18). At least one temperature sensor (22) detecting the temperature of said air stream is arranged inside the duct (18).