Yankee Drying Hood Dual-Temperature Air Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Yankee drying hood arrangements face challenges in achieving uniform moisture profiles across the paper web due to variations in heating, leading to inefficient energy use and increased resistance in air flow systems.
Innovation Solution
The Yankee drying hood arrangement features a plurality of nozzle boxes distributed around an imaginary axis, with each nozzle box having openings for fluid to exit and reach the cylindrical surface at different points, and includes two main supply conduits for hot air at different temperatures, allowing for variable mixing to maintain consistent flow rates and adjust drying effects without increasing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dampers are closed to reduce drying in one area, then the dryness profile in that area is improved, but the fluid flow resistance increases and energy consumption increases
Solution Approach 1:
The air distribution system is divided into multiple independent distributor conduits, each serving a specific zone of the Yankee drying cylinder. This segmentation allows independent control of air flow to different areas without affecting the entire system, enabling precise local drying control without global flow restriction and associated energy penalties.
Solution Approach 2:
Each distributor conduit is equipped with its own damper, allowing localized adjustment of air flow based on the specific drying requirements of the corresponding zone. This local control mechanism enables optimization of drying performance in each area while maintaining efficient overall system operation, avoiding the energy waste of system-wide flow restriction.
2Manufacturing precision
If dampers are closed to reduce drying in one area, then the dryness profile in that area is improved, but the fluid flow resistance increases
Solution Approach 1:
The air distribution system is divided into multiple independent distributor conduits, each serving a specific zone of the Yankee drying cylinder. This segmentation allows independent control of air flow to different areas without affecting the entire system, enabling precise local drying control without global flow restriction and associated energy penalties.
Solution Approach 2:
Each distributor conduit is equipped with its own damper, allowing localized adjustment of air flow based on the specific drying requirements of the corresponding zone. This local control mechanism enables optimization of drying performance in each area while maintaining efficient overall system operation, avoiding the energy waste of system-wide flow restriction.
3Adaptability or versatility
If single temperature air supply is used, then the system is simple, but the ability to adjust drying effects is limited
Solution Approach 1:
The system combines multiple air supply conduits carrying air at different temperatures into a common distribution network. By merging these parallel supply channels, the system achieves versatile drying control through temperature variation while maintaining a relatively simple overall structure, as the conduits share common distributor boxes and nozzles.
Solution Approach 2:
The invention utilizes parameter changes by varying the temperature of the air supplied to different zones through the parallel conduits. This parameter variation (temperature) provides an additional degree of freedom for drying control, allowing fine-tuning of drying effects without requiring complex mechanical adjustments or multiple independent control systems.
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 design achieves more even heating and moisture profiles across the paper web, reducing energy waste and maintaining consistent air flow resistance.
Implementation Method 1
a Yankee hood to increase the drying effect. The Yankee hood typically has a drying fluid, typically air, supply system for supplying air that is blown against the paper web as the paper web travels over the cylindrical surface of the Yankee cylinder. The supplied air heated so it can aid evaporation of the water that is present in the paper web.
Implementation Method 2
The supplied air heated so it can aid evaporation of the water that is present in the paper web
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a Yankee drying hood arrangement (1) which has a first temperature main supply conduit (9, 9') for a fluid such as hot air, or hot air and steam and/or water vapour, at a first temperature T1 and a second temperature main supply conduits (10, 10') for a fluid such as hot air, or hot air and steam and/or water vapour, at a second temperature T2 which is not the same as T1, the first temperature and second temperature main supply conduits (9, 9', 10, 10') being in communication with the distributor conduits (8) such that a fluid such as hot air can stream from the first temperature and second temperature main supply conduits (9, 9', 10, 10') to the distributor conduits (8), wherein at least one distributor conduit (8) is provided with damper means (31) for changing the ratio between amount of fluid at temperature T1 from the first temperature main conduit and the amount of fluid at temperature T2 from the second temperature main conduit that streams into the distributor conduit.