Direct Heated Edge Director Assembly for Glass Devitrification Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing glass manufacturing processes face challenges with devitrification, where molten glass crystallizes along the edges of edge directors, leading to defects in the glass ribbon and disrupted bead development.
Innovation Solution
A glass forming apparatus is designed with a forming body having converging surfaces and an edge director assembly with bus bar assemblies that are electrically connected to a power supply to supply alternating current, effectively heating the edge directors and mitigating devitrification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal edge directors are attached at the ends of the forming body to control lateral contraction, then the width loss from lateral contraction is mitigated, but the molten glass temperature falls below the liquidus temperature causing devitrification and crystallization along the edges
Solution Approach 1:
The patent changes the temperature parameter of the edge directors by applying electrical heating to maintain them above the liquidus temperature of the molten glass, preventing devitrification while preserving the width control function
Solution Approach 2:
The patent introduces heating elements as an intermediary mechanism to transfer thermal energy to the edge directors, ensuring they maintain the necessary temperature to prevent crystallization of molten glass
2Temperature
If the forming body is made from refractory ceramic material, then it can withstand high temperatures, but metal edge directors attached to it conduct heat away causing the molten glass to cool and crystallize
Solution Approach 1:
The patent converts the heat-conducting property of metal edge directors from a harmful effect into a beneficial one by using electrical heating to control the temperature, ensuring heat is maintained rather than lost to prevent devitrification
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 solution effectively prevents devitrification by maintaining the molten glass at a temperature above its liquidus, thereby reducing defects in the glass ribbon and ensuring stable bead development.
Implementation Method 1
a first bus bar assembly joined to the first edge director, a second bus bar assembly joined to the second edge director, a third bus bar assembly joined to the edge director assembly at the edge portion joint. The first, second, and third bus bar assemblies are electrically connected to an electrical power supply configured to supply an alternating electrical current to the edge director assembly
Data Source
AI summary
A glass manufacturing apparatus including a forming apparatus having a forming body and a directly electrically heated edge director assembly attached thereto, the edge director assembly configured to direct a flow of molten glass from the forming body. The edge director assembly includes a plurality of bus bar assemblies connected thereto and configured to receive an electrical current. The electrical current may be a three-phase electrical current. The bus bar assemblies are supported by three-axis support assemblies that support movement of the bus bar assemblies along three orthogonal axes.