Glass Ribbon Cooling Tube Geometry for Uniform Edge Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional glass ribbon forming devices cause overcooling of end portions, leading to high stress and increased breakage risk due to uneven cooling, which also results in excessive condensation.
Innovation Solution
A cooling tube with a non-constant diameter is used, featuring a larger central portion and thermally insulated end portions to differentially control heat extraction, ensuring faster cooling of the central region while minimizing end portion cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional forming device is used to cool the glass ribbon, then the glass ribbon can be cooled during travel, but the end portions are cooled more than desired causing overcooling
Solution Approach 1:
The cooling tube is designed with non-uniform diameter where the central portion has a larger diameter than the end portions. This local geometric variation creates different cooling rates at different locations along the glass ribbon, allowing the center to be cooled more aggressively while the ends are cooled more conservatively, thereby eliminating overcooling and associated stress problems
Solution Approach 2:
The patent changes the geometric parameter (diameter) of the cooling tube along its length to create a gradient in cooling intensity. By varying the diameter parameter from the center toward the ends, the system achieves spatially differentiated cooling behavior that matches the different thermal requirements of different glass ribbon regions
2Loss of energy
If the end portions are cooled more, then heat extraction is increased, but this leads to excessive condensation on the transition wall
Solution Approach 1:
The cooling tube incorporates local geometric variations with smaller diameter at the ends compared to the center. This local quality change reduces the heat transfer surface area and cooling intensity at the end portions, preventing excessive heat extraction that would otherwise cause condensation on the transition wall
3Ease of manufacture
If a uniform diameter cooling tube is used, then manufacturing is simple, but uneven cooling occurs causing high stress in the glass ribbon
Solution Approach 1:
The cooling tube features deliberate local geometric variations with a larger central diameter and smaller end diameters. These localized changes in geometry are designed into the manufacturing process to create non-uniform cooling patterns that prevent stress concentration in the glass ribbon, balancing manufacturing feasibility with stress reduction
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 reduces stress and breakage risk by uniformly cooling the glass ribbon, preventing excessive condensation and maintaining structural integrity.
Implementation Method 1
The cooling tube is hollow and filled with a cooling fluid. The cooling tube is positioned adjacent to a glass ribbon and functions to extract heat from the glass ribbon.
Implementation Method 2
a sleeve comprising a thermally insulating material may surround the end portions, further reducing the heat extraction by the end portions
Data Source
AI summary
A glass forming apparatus includes a cooling tube positioned adjacent to a travel path of a glass ribbon. The cooling tube includes a central portion including a first sidewall surrounding a central chamber and extending along a tube axis. The cooling tube includes an end portion including a second sidewall surrounding an end chamber. The end portion extends along the tube axis and is attached to the central portion. The cooling tube receives a cooling fluid within the central chamber and the end chamber. A sleeve extends along the tube axis and circumferentially surrounds the end portion. The sleeve includes a sleeve wall spaced radially apart from the second sidewall, and a thermally insulating material positioned between the sleeve wall and the second sidewall. Methods of forming a glass ribbon with a glass forming apparatus are provided.