Dryer Drum and Airflow Sequencing for Delicate Laundry Drying
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Solution Overview
Problem
Existing laundry drying technologies do not effectively address the need for gentle drying of delicate items, often resulting in creases and inadequate mechanical treatment.
Innovation Solution
A method and apparatus for controlling a drying cycle in a laundry dryer that alternates between two rotation directions and air flow rates, with a first phase using a lower air flow rate and alternating rotation, and a second phase using a higher air flow rate and mainly forward rotation, to gently treat delicate laundry while minimizing creases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional drying methods are used with high air flow rates and continuous drum rotation, then drying efficiency is improved, but delicate laundry suffers mechanical damage and creases
Solution Approach 1:
The patent applies periodic action by alternating between two drying phases with different drum rotation patterns. The first phase uses alternating main and counter rotation directions with lower air flow rates, while the second phase uses mainly main rotation direction with higher air flow rates. This periodic alternation allows the laundry to be gently treated during the first phase and efficiently dried during the second phase, preventing both mechanical damage and creases while maintaining high drying efficiency.
Solution Approach 2:
The patent implements dynamics by making the drum rotation direction and air flow rate variable rather than constant. The control unit dynamically adjusts the drum rotation between main and counter directions, and modulates the air flow rate between low and high levels based on the drying phase. This dynamic control allows optimal balancing between gentle treatment and efficient drying at different stages of the drying cycle.
2Loss of time
If high air flow rates are used throughout the drying cycle, then drying time is reduced, but delicate laundry is subjected to excessive mechanical treatment
Solution Approach 1:
The patent applies segmentation by dividing the drying cycle into two distinct phases with different air flow rates and drum rotation patterns. The first drying phase uses lower air flow rates and alternating rotation to provide gentle treatment, while the second drying phase uses higher air flow rates and mainly forward rotation to reduce drying time. This segmentation allows each phase to optimize for its specific function without compromising the other.
Solution Approach 2:
The patent implements preliminary action by performing gentle mechanical treatment in the first drying phase before applying high air flow rates in the second phase. During the first phase, the alternating drum rotation and lower air flow prepare the laundry by removing excess moisture gently without causing mechanical damage. This preliminary gentle treatment ensures that when high air flow rates are applied in the second phase, the laundry can withstand the more intensive drying conditions without excessive mechanical treatment.
3Object-affected harmful factors
If alternating drum rotation is used throughout the drying cycle, then creases are minimized, but drying efficiency decreases
Solution Approach 1:
The patent applies periodic action by using alternating drum rotation only during the first drying phase to minimize creases, then switching to mainly forward rotation during the second phase to improve drying efficiency. The control unit alternates the drum rotation between main and counter directions during the first phase, and predominantly maintains main rotation direction during the second phase. This periodic application of alternating rotation allows crease prevention when needed while maintaining high drying efficiency when appropriate.
Solution Approach 2:
The patent implements parameter changes by modifying the drum rotation pattern and air flow rate parameters based on the drying phase. During the first phase, the drum rotation alternates between main and counter directions with lower air flow rates to prevent creases. During the second phase, the drum rotation changes to mainly forward direction with higher air flow rates to maximize drying efficiency. These parameter changes allow optimal balancing between crease prevention and drying efficiency at different stages.
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 ensures gentle mechanical treatment and reduced creasing of delicate items, such as silk, while efficiently completing the drying process in a shorter time, using a heat pump system and condensation dryer technology.
Implementation Method 1
A heating element is arranged in the channel arrangement for heating the drying air
Implementation Method 2
a blower arranged in the channel arrangement is adapted to convey the drying air
Implementation Method 3
using a heat pump system and condensation dryer technology
Data Source
AI summary
A method of controlling a drying cycle for drying delicate laundry in a laundry drying apparatus, in particular in a dryer or in a washer-dryer, wherein the laundry drying apparatus has a cabinet, a rotatable drum adapted to receive laundry to be dried, and a drying air channel arrangement designed to guide drying air through the drum for drying the laundry in the drum. The drying air is heated by a heating element and a blower is arranged in the channel arrangement adapted to convey the drying air. A drum motor is adapted to rotate the drum selectively in a main rotation direction (58) and in a counter rotation direction (66). The method includes a drying phase sequence (60) having a first drying phase (62) and subsequently a second drying phase (64). In the first drying phase (62) the drum is rotated alternately in the main and the counter rotation direction (58, 66) while the drying air is conveyed at a first average flow rate through the drum. In the second drying phase (64) the drum is rotated in the main rotation direction (58) while the drying air is conveyed at a second average flow rate through the drum, wherein the first average flow rate is lower than the second average flow rate.