Glass Furnace Primary Recirculation Loop Control
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Solution Overview
Problem
Existing glass furnaces face challenges in maintaining high-quality refining of ultra-clear glass, including deterioration in refining quality, increased corrosion of internal walls, and elevated temperatures, which require adjustments such as lowering the draw rate or increasing tank depth, leading to increased costs and longer tinting times.
Innovation Solution
A glass furnace with a double recirculation loop system that slows down the primary recirculation loop by reducing its length through a heat supply to the return glass at floor level, combined with a reduction in tank depth and geometric modifications like inclined hearths or obstacles, to extend the refining zone and reduce recirculation intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the primary recirculation loop is slowed down to extend refining time, then glass refining quality is improved, but the recirculation intensity decreases which may affect furnace productivity
Solution Approach 1:
The patent applies local quality by creating a specific thermal environment only in the primary recirculation loop zone. A localized heat source (such as a radiant heater or heating element) is positioned to heat only the glass in the primary loop, reducing its viscosity and slowing its flow. This allows extended refining time for this specific circulation path without affecting the overall furnace productivity or secondary loop circulation.
Solution Approach 2:
The patent changes the temperature parameter locally in the primary recirculation loop by introducing additional heating. This temperature increase reduces the viscosity of the glass in this zone, which paradoxically slows down the recirculation flow by reducing the driving force for circulation. The parameter change is localized and does not affect the global furnace temperature or secondary loop, thus maintaining productivity while improving refining quality.
2Manufacturing precision
If the tank depth is increased to extend refining zone, then glass refining quality is improved, but construction cost and energy consumption increase
Solution Approach 1:
Instead of increasing the overall tank depth, the patent applies local quality by extending the refining zone horizontally through the primary recirculation loop. The glass is made to circulate through a longer path at the surface level where refining occurs, effectively increasing the refining zone length without increasing tank depth. This approach avoids the high construction costs and energy consumption associated with deeper tanks.
Solution Approach 2:
The patent transitions from vertical extension (increasing tank depth) to horizontal extension (lengthening the primary recirculation loop path). By utilizing the horizontal dimension and creating a longer circulation path at the surface, the refining zone is extended without the need for increased tank depth, thereby avoiding the associated costs and energy consumption.
3Manufacturing precision
If the draw rate is lowered to maintain refining quality, then glass quality is preserved, but furnace productivity decreases
Solution Approach 1:
The patent segments the glass circulation into two independent loops: a primary loop that circulates slowly through the refining zone, and a secondary loop that maintains overall furnace circulation and productivity. The primary loop is dedicated to refining with extended residence time, while the secondary loop ensures continuous glass flow to the outlet. This segmentation allows the draw rate to be maintained without compromising refining quality, as the primary loop provides the necessary extended refining time independently.
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 enhances the quality of glass production by extending the refining time, reducing corrosion risks, and lowering temperatures, while maintaining or increasing furnace output, thus addressing the specific challenges of ultra-clear glass production without the drawbacks of prior methods.
Implementation Method 1
a heat supply to the return glass circulating at floor level capable of slowing down the primary recirculation loop and shortening its extent, said heat supply being localized in the return glass, the reduction in the viscosity of the glass remaining low
Implementation Method 2
Two liquid glass recirculation loops B1, B2 are formed in the bath between a central zone I of the hotter furnace and respectively the inlet E and the outlet Y at a lower temperature
Data Source
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AI summary
A glass furnace for heating and melting materials to be vitrified, in which two molten glass recirculation loops (B1, B2) are formed in the bath between a hotter central zone (I) of the furnace and, respectively, the inlet and outlet at a lower temperature; the furnace includes a means (X) for slowing the flow of molten glass in the primary recirculation loop (B1) to shorten the loop's length. This slowing means is a heat supply means for the return glass circulating at the furnace floor.