Air Flotation Dryer Speed and Temperature Control
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Solution Overview
Problem
Existing flotation dryers for impregnated paper webs face issues with web brittleness and tearing due to incorrect conveying speed and temperature settings, leading to complex manual interventions and significant waste during web breaks.
Innovation Solution
A flotation dryer design with a levitation channel that adjusts conveying speed and fluid temperature to maintain a predetermined moisture content, allowing for rapid switching between hot and cold fluid application to prevent web brittleness and facilitate easy web insertion or replacement without waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the conveying speed of the paper web is reduced to improve drying quality, then the paper web becomes over-dried and brittle, but this leads to web tearing and requires complex manual intervention
Solution Approach 1:
The dryer dynamically adjusts the conveying speed of the paper web during the drying process. The speed is varied according to the drying stage and moisture content requirements, allowing optimal drying quality without causing brittleness. This dynamic speed adjustment prevents web tearing while maintaining ease of operation.
Solution Approach 2:
The system changes multiple parameters simultaneously including conveying speed, air temperature, and air flow rate. By coordinating these parameter changes, the dryer achieves high drying quality while preventing web brittleness and tearing, thus avoiding manual intervention and web waste.
2Productivity
If the conveying speed is increased to improve productivity, then less web waste is produced, but the paper web cannot be dried sufficiently
Solution Approach 1:
The dryer employs coordinated parameter changes where increased conveying speed is compensated by adjusting air temperature and extending the drying path. This allows high productivity to be maintained while ensuring sufficient drying quality is achieved through the combined effect of multiple parameters.
Solution Approach 2:
The drying action continues effectively throughout the entire drying path even at high conveying speeds. The system ensures continuous and uniform drying along the web's path, maintaining drying quality while achieving high productivity through optimized air distribution and extended exposure time.
3Productivity
If high conveying speed is used to improve productivity, then web break and waste are reduced, but complex manual intervention is required when web breaks occur
Solution Approach 1:
The dryer incorporates feedback mechanisms that monitor web tension, moisture content, and drying conditions in real-time. This feedback allows automatic adjustments to conveying speed and drying parameters, preventing web breaks and eliminating the need for complex manual intervention when issues occur.
Solution Approach 2:
The system is designed to automatically handle web breaks and insert new web sections without requiring complex manual intervention. The self-service mechanism includes automatic web detection, stopping, and replacement functions that maintain productivity while simplifying operator tasks.
4Productivity
If the temperature of the air flow is increased to improve drying efficiency, then drying speed increases, but the paper web becomes brittle and tears
Solution Approach 1:
The dryer coordinates temperature changes with conveying speed adjustments. When air temperature is increased to improve drying efficiency, the conveying speed is simultaneously optimized to prevent over-drying and brittleness. This coordinated parameter control maintains web strength while achieving high drying efficiency.
Solution Approach 2:
The drying process applies different temperature levels to different sections of the paper web based on local moisture content and drying requirements. This localized quality control prevents uniform overheating that would cause brittleness, while still achieving high overall drying efficiency through targeted high-temperature zones.
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 dryer ensures reliable drying with minimal waste by maintaining the web's moisture content and preventing brittleness, allowing for quick adjustments in speed and fluid application to support seamless operation and maintenance.
Implementation Method 1
a hot fluid or a cold fluid can be fed, with the proviso that the material web in the levitation channel can be acted upon by the hot fluid or the cold fluid from above and from below
Implementation Method 2
the material web can be guided in the levitation channel in a freely floating or contact-free manner
Data Source
Figure 1
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Figure 3
AI summary
The dryer i.e. air flotation dryer (21), has an upper blowing unit (10) provided above a floating channel (7), and a lower blowing unit (12) provided below the floating channel. A material strip (9) is made to act up with hot fluid or cold fluid that are conveyed or transported into the floating channel during operating condition of the dryer. A shut-off element (25) is reversibly actuated to switch from the operating condition to the start-up condition. The hot fluid is passed forward to the blowing units in a start-up condition or by changing the start-up condition.