Clothes Dryer Re-Ignition Control for Overheating Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional clothes dryers cause damage to clothes due to overheating, especially in the latter half of the drying cycle, as they cannot distinguish the type and amount of clothes, leading to excessive drying and bruising.
Innovation Solution
A clothes dryer that adjusts the re-ignition temperature gradually, using the point at which the exhaust temperature drops to the re-ignition temperature as a reference, to supply unheated air and lower the drum temperature, allowing for uniform drying without strictly estimating the type and amount of clothes, thereby reducing overheating damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the burner is re-ignited when the exhaust temperature reaches the predetermined re-ignition temperature, then the drying operation continues efficiently, but the temperature inside the drum keeps rising and causes damage to clothes
Solution Approach 1:
The patent applies dynamics by making the re-ignition temperature variable rather than fixed. The control unit dynamically adjusts the re-ignition temperature based on the elapsed time from the start of the drying operation. Specifically, when the elapsed time exceeds a predetermined threshold, the re-ignition temperature is lowered from the initial high value to a lower value, preventing excessive temperature rise and clothes damage while maintaining drying efficiency.
Solution Approach 2:
The patent changes the temperature parameter over time. The re-ignition temperature parameter is adjusted based on the elapsed time condition. In the initial phase, a higher re-ignition temperature is used for efficient drying, while in the later phase, the re-ignition temperature is reduced to prevent overheating damage, thus optimizing both drying performance and clothes protection.
2Object-affected harmful factors
If the upper limit temperature is lowered in the latter half of the operation to prevent overheating, then clothes damage is reduced, but it is difficult to determine when the latter half begins without knowing the type and amount of clothes
Solution Approach 1:
The system uses the elapsed time information, which is naturally available from the operation start, to automatically determine when to switch temperature regimes. This self-service approach eliminates the need for external inputs about clothes type or amount, as the time-based criterion inherently adapts to the drying process progress.
Solution Approach 2:
The patent establishes a predetermined time threshold in advance that automatically divides the drying operation into initial and latter halves. This preliminary setting allows the system to know when to lower the re-ignition temperature without needing real-time analysis of clothes characteristics, simplifying the control logic while maintaining effectiveness.
3Object-affected harmful factors
If the burner is stopped to lower the temperature inside the drum, then clothes overheating is prevented, but the drying operation time increases
Solution Approach 1:
The patent implements periodic temperature adjustment through the heating control unit, which intermittently stops and restarts the burner based on temperature conditions. This periodic action allows the drum temperature to fluctuate within acceptable ranges, preventing clothes damage while maintaining overall drying progress through cyclical heating and cooling phases.
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 reduces peak temperatures and prevents excessive overheating, ensuring uniform drying while minimizing damage to clothes, with a non-adjustable burner reducing manufacturing costs and maintaining necessary drying performance.
Implementation Method 1
air for drying heated by a burner is blown into a drum
Implementation Method 2
exhaust temperature detection unit for detecting a temperature of the air for drying discharged from the drum
Implementation Method 3
air for drying heated by a burner is blown into a drum into which clothes to be dried is introduced by a fan
Implementation Method 4
air for drying heated by a burner is blown into a drum
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3
AI summary
Provided is a clothes dryer, which is capable of lowering a temperature of clothes during the latter half of an operation regardless of the type and the amount of the clothes and uniformly drying all the clothes while fully reducing damages to the clothes caused by overheating. The clothes dryer (1) of the present invention includes a drum (20), an air supply and exhaust unit (4) for supplying and discharging the air for drying to and from the drum (20), a burner (30) for heating the air for drying, a temperature sensor (31) for detecting the exhaust temperature, and a heating control unit (55) for performing a temperature adjustment processing. The temperature adjustment processing enables the burner (30) to stop when the exhaust temperature reaches an upper limit temperature and enables the burner (30) to re-operate when the exhaust temperature is lowered to a specified re-ignition temperature. The heating control unit (55) is provided with a re-ignition temperature adjustment part that performs an adjustment to lower the re-ignition temperature, and the re-ignition temperature is gradually lowered through the re-ignition temperature adjustment part every time when the temperature adjustment processing is repeated and intermittently to perform the re-ignition.