Zigzag Air Injection Nozzle Layout for Uniform Resin Film Heating
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Solution Overview
Problem
Conventional air ejection nozzles in tenter ovens face challenges in achieving uniform heat transfer efficiency across the width of resin films, leading to temperature irregularities and non-uniform properties in biaxially oriented resin films.
Innovation Solution
An air ejection nozzle design with circular holes arranged in two zigzag rows perpendicular to the resin film's carrying direction, where the distance between the nozzle face and the film, hole diameter, and hole spacing are optimized to satisfy specific ratios, ensuring uniform heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If air ejection holes are arranged in a conventional pattern (single row or non-zigzag arrangement), then the nozzle structure is simple, but the heat transfer efficiency is non-uniform across the resin film width due to air jet bending
Solution Approach 1:
The patent applies asymmetry by arranging air ejection holes in a zigzag pattern rather than a straight line. The holes are positioned at alternating offsets in two rows, creating an asymmetric distribution that prevents air jet bending and ensures uniform heat transfer across the resin film width. This asymmetric arrangement is defined by specific geometric relationships (formulas 1-3) between hole positions, spacing, and nozzle-to-film distance.
2Manufacturing precision
If the distance between air ejection face and resin film is large, then the air jets do not bend and interfere with each other, but the heat transfer efficiency decreases
Solution Approach 1:
The patent optimizes the parameter L (distance between air ejection face and resin film) to satisfy formula 2 (4 ≤ L/D ≤ 8), where D is the hole diameter. This parameter change ensures that air jets remain coherent and do not bend while maintaining sufficient heat transfer efficiency. The optimal L value balances jet stability with thermal coupling between the air and resin film.
3Area of stationary object
If multiple air ejection nozzles are installed to cover the resin film width, then the heat coverage is improved, but the temperature uniformity across the width deteriorates due to air jet bending in each nozzle
Solution Approach 1:
The patent segments the air ejection system into multiple nozzles, each containing multiple holes arranged in zigzag rows. This segmentation allows each nozzle to independently cover a specific width region while maintaining uniform heat transfer through the zigzag pattern. The segmented approach enables full width coverage without the temperature non-uniformity that would result from conventional single-row arrangements.
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 excellent uniformity in heat transfer efficiency across the resin film's width, resulting in homogeneous heat-treated properties and improved film quality.
Implementation Method 1
The air controlled to a desired temperature by the heat exchanger is sent by the fan to the respective air ejection holes through the air supply duct and the air supply passage in the nozzle housing, and is ejected toward the surface of the resin film from the respective air ejection holes open in the air ejection face of the housing. The ejected air is usually collected from suction ports formed in the tenter oven, to be reused.
Implementation Method 2
one end of the air supply duct communicates with the air supply passage in the nozzle housing while the other end is connected with a heat exchanger and a fan. The air controlled to a desired temperature by the heat exchanger is sent by the fan to the respective air ejection holes
Data Source
AI summary
Provided is an air injection nozzle, which is used for a heat treatment such as the heating, cooling or thermal insulation of a running sheet (or film) with injected air. In the air injection face, a number of air injection holes are so arrayed at an interval (Py) in first and second rows that the air injection holes of a first row and the air injection holes of a second row are staggered. The first row and the second row are positioned at an interval (Px). The air injection face and the sheet running face confront each other at a distance (L). The air injection holes in the air injection face have a diameter (D). The interval (Px), the interval (Py), the distance (L) and the diameter (D) satisfy Formula (1): 6≦(L/D)/(Px/Py)≦9, and Formula (2): 4≦L/D≦8. This air injection nozzle is employed as a resin film heat treating apparatus in a tenter oven to be used for manufacturing the resin film.