Cool down logic for condensing type dryers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Condensing type dryer systems often result in laundry articles having higher than anticipated moisture content at the end of the drying cycle due to residual moisture being circulated and absorbed during the cooling portion, leading to consumer dissatisfaction.
Innovation Solution
A laundry appliance with a conditioning system comprising a dehumidification section and a heating section, a recirculating air flow system, and a fan that operates at different speeds during various portions of the drying cycle to manage air flow and moisture effectively, ensuring proper drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling portion circulates process air through the basket to cool the articles, then the articles are cooled down, but residual moisture in the system is circulated and absorbed by the laundry articles resulting in higher than anticipated moisture content
Solution Approach 1:
The cooling portion is segmented into multiple cooling cycles, where the total cooling time is divided into several intervals. During each interval, the fan operates to circulate air for a predetermined period, then stops for a predetermined period. This segmentation allows moisture to settle or be removed during stop intervals while still achieving cumulative cooling effect, thereby reducing residual moisture circulation compared to continuous cooling.
Solution Approach 2:
The fan operation during the cooling portion follows a periodic pattern - running for predetermined intervals and stopping for predetermined intervals. This periodic action disrupts the continuous circulation of moisture-laden air that would otherwise be absorbed by the laundry articles, while maintaining sufficient air movement to achieve the desired cooling effect over the complete cooling portion duration.
2Speed
If the fan operates at high speed during the cooling portion to enhance air circulation, then cooling efficiency is improved, but more residual moisture is circulated and absorbed by the laundry articles
Solution Approach 1:
The fan operates periodically during the cooling portion - at high speed for predetermined intervals to achieve adequate cooling, then stops for predetermined intervals to allow moisture to settle or be removed. This periodic high-speed operation provides sufficient cooling effect while minimizing the continuous circulation of moisture-laden air that would be absorbed by the laundry articles.
Solution Approach 2:
The stop intervals in the periodic fan operation serve as preliminary anti-action by allowing moisture to settle or be removed from the air stream before the next high-speed circulation begins. This prevents the accumulation and re-circulation of moisture that would occur with continuous high-speed operation.
3Temperature
If the cooling portion duration is extended to ensure thorough cooling, then cooling effectiveness is improved, but more residual moisture is circulated and absorbed by the laundry articles
Solution Approach 1:
The cooling portion is segmented into multiple cooling cycles with alternating on/off fan operation. This segmentation allows the system to achieve thorough cooling over the extended duration while periodically stopping moisture circulation. The cumulative cooling effect across multiple segments achieves the desired temperature reduction without continuously circulating moisture-laden air.
Solution Approach 2:
The periodic operation pattern - fan running for predetermined intervals and stopping for predetermined intervals - allows the cooling portion to extend in duration while minimizing moisture circulation. Each on-period contributes to cooling effectiveness, while each off-period allows moisture to settle or be removed, resulting in thorough cooling with reduced moisture absorption.
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
The solution ensures that laundry articles are thoroughly dried by controlling air flow and moisture levels, reducing the likelihood of residual moisture absorption and enhancing consumer satisfaction with the drying process.
Implementation Method 1
a basket tumbles the wet laundry articles as heated process air flows through the basket to pick up moisture evaporated from the articles. The process air is urged by a fan through ducts to a heat pump including an evaporator to remove some of the moisture from the air and a condenser to heat the air
Implementation Method 2
an evaporator to remove some of the moisture from the air
Data Source
AI summary
A method of operating a laundry appliance includes rotating a laundry basket at a tumble speed during a drying cycle of a laundry appliance and energizing a conditioning system for process air. A fan is operated at a first speed to recirculate a flow of process air for a portion of a drying cycle. The conditioning system is deenergized and the fan is operated at a second speed during a second portion of the drying cycle where the second speed less than the first speed.