Float Glass Plate Water Concentration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of natural gas and oxygen gas in glass melting furnaces for float glass production often results in defects on the bottom surface of float glass plates due to uneven water concentration and elution from the molten glass to the molten metal, leading to concave portions and reduced quality.
Innovation Solution
A float glass plate with controlled water concentration and manufacturing method where the molten glass is supplied onto molten metal with a specific water amount elution ratio, ensuring a uniform distribution and maximum water concentration within optimal limits, and using alkali-free glass compositions to minimize defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If natural gas and oxygen gas are used in glass melting furnaces to improve thermal efficiency and reduce emissions, then energy efficiency is improved, but defects (concave portions) are generated on the bottom surface of float glass plates due to uneven water concentration
Solution Approach 1:
The patent controls the water concentration in molten glass within specific ranges (0.03-0.20 mass%) and manages the water amount eluted to molten metal (0.5-2.0% of initial water amount) to prevent defect formation while maintaining the benefits of natural gas and oxygen gas combustion. This parameter control resolves the contradiction by optimizing chemical composition parameters to eliminate surface defects despite using clean combustion gases.
2Manufacturing precision
If water concentration in molten glass is increased to improve glass quality, then defect formation is reduced, but excessive water elution to molten metal occurs causing concave portions on the bottom surface
Solution Approach 1:
The patent establishes optimal parameter ranges: water concentration in molten glass of 0.03-0.20 mass% and water amount eluted to molten metal of 0.5-2.0% of the initial water amount. These controlled parameter changes ensure sufficient water concentration to maintain glass quality while limiting excessive elution that causes surface defects.
Solution Approach 2:
The patent implements control of water concentration based on monitoring and managing the elution process to molten metal. By establishing feedback loops that track water concentration changes and elution amounts, the system maintains optimal ranges to prevent both insufficient water concentration (causing defects) and excessive elution (causing concave portions).
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 provides a high-quality float glass plate with reduced defects and improved manufacturing efficiency by maintaining a water concentration ratio between 0.5% and 2% and using specific glass compositions, enhancing both quality and productivity.
Implementation Method 1
The molten glass is cooled while flowing on the molten metal in a predetermined direction
Implementation Method 2
a water amount eluted from the molten glass to the molten metal is more than 0.5% and 2.0% or less of a water amount in the molten glass immediately before being supplied into the bath
Data Source
AI summary
The present invention relates to a float glass plate that is formed by continuously supplying a molten glass onto a molten metal in a bath and allowing the molten glass to flow on the molten metal, wherein the float glass plate satisfies the following expression (1) when, on a coordinate axis that is parallel to a through-thickness direction and has, as an origin, an arbitrary point on a principal surface which is positioned on the molten metal side in the bath among both principal surfaces of the float glass plate, a water concentration in glass at a coordinate x (μm) indicating a distance from the origin is represented by C(x) (mass ppm), the thickness of the float glass plate is represented by D (μm), a maximum value of the C(x) is represented by Ca (mass ppm), and a coordinate at which the C(x) is maximum is represented by Da (μm).[Math.1]0.5<∫0Da(Ca-C(x))ⅆxCa×D×100≦2.0(1)