Staged Heating for Bubble Removal in Viscous Liquids
Solution Overview
Problem
Conventional methods for removing gaseous inclusions from viscous liquids, such as molten glass, are inefficient and costly, requiring large equipment or long refining times due to the slow rise of bubbles under high viscosity conditions, especially for small bubbles which take longer to reach the surface and often require overheating, leading to volatilization and refractory wear.
Innovation Solution
A method involving a refining chamber with staged heating, where the bottom portion of the viscous liquid is initially heated to reduce viscosity and create convective flow, followed by heating from above to drive bubbles to the surface, avoiding overheating and promoting coalescence, thereby reducing refining time significantly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional heating methods are used to remove gaseous inclusions from viscous liquids, then bubbles will eventually rise to the surface, but the process requires excessively long residence times and large, costly equipment
Solution Approach 1:
The patent changes the temperature parameter distribution within the liquid by applying localized heating zones. The first heating zone creates a temperature gradient that reduces viscosity in specific regions, accelerating bubble rise velocity without requiring uniform overheating of the entire liquid volume. This selective parameter change resolves the contradiction by maintaining fast bubble removal while avoiding excessive energy input and long residence times.
Solution Approach 2:
The heating system is segmented into multiple distinct heating zones (first heating zone and second heating zone) with different temperature levels and functions. The first zone creates convective flow to initiate bubble movement, while the second zone provides additional heating to maintain low viscosity in the upper region. This segmentation allows the system to achieve rapid bubble removal without requiring the entire liquid volume to be overheated, thus reducing refining time while avoiding the need for large, costly equipment.
2Speed
If the liquid is overheated to reduce viscosity and accelerate bubble rise, then bubble removal speed increases, but volatilization and refractory wear increase
Solution Approach 1:
The patent applies heating locally rather than uniformly throughout the liquid volume. The first heating zone is positioned to create convective flow in the lower region, while the second heating zone maintains lower viscosity in the upper region where bubbles rise. This local quality approach ensures that viscosity is reduced only in the regions necessary for bubble removal, achieving high bubble rise velocity without overheating the entire liquid volume, thereby minimizing volatilization and refractory wear.
Solution Approach 2:
The first heating zone performs preliminary heating to create convective flow and initiate bubble movement before the bubbles reach the upper regions. This preliminary action reduces the viscosity gradient and starts the bubble rise process early, allowing the second heating zone to maintain rather than create the temperature conditions. This sequential approach achieves rapid bubble removal while avoiding the need for sustained high-temperature overheating that would cause volatilization and refractory wear.
3Productivity
If uniform heating is applied throughout the liquid, then viscosity is reduced and bubble rise is accelerated, but energy consumption increases and volatilization occurs
Solution Approach 1:
The patent changes the spatial distribution of the temperature parameter rather than applying uniform heating. By creating localized heating zones with specific temperature gradients, the system reduces viscosity only in the regions where it is necessary for bubble removal. This selective parameter change achieves high bubble removal efficiency while minimizing the total energy input required, avoiding the energy waste and volatilization associated with uniform overheating of the entire liquid volume.
Solution Approach 2:
The heating system is divided into segmented zones with different power levels and functions. The first heating zone provides intensive localized heating to create convective flow, while the second heating zone provides maintenance heating in the upper region. This segmentation allows the system to achieve rapid bubble removal efficiency without requiring uniform high-energy input throughout the liquid volume, thus reducing overall energy consumption while preventing volatilization.
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 refining time by a factor of 100 to 150, allowing for the efficient removal of small bubbles in 10-30 minutes, making the process cost-effective and practical for industrial-scale glass production without volatilization or excessive wear.
Implementation Method 1
the viscosity of the bottom portion of the viscous liquid layer is reduced in a first refining zone... producing an upwardly mobile reduced viscosity portion of the viscous liquid layer
Implementation Method 2
Heat is then introduced into the viscous liquid layer from above the viscous liquid layer in a second refining zone... reducing the gaseous inclusions in the viscous liquid layer
Implementation Method 3
Under normal gravity conditions, a gaseous inclusion, or bubble, will rise to the upper surface of a liquid. This is a consequence of the lower density of the insoluble gas.
Implementation Method 4
the rate at which the gaseous inclusions rise to the surface decreases with increases in liquid viscosity
Data Source
AI summary
A method for removing gaseous inclusions from a viscous liquid in which a viscous liquid stream having gaseous inclusions is introduced into a refining chamber, resulting in a flowing viscous liquid layer. The viscosity of a bottom portion of the viscous liquid layer is reduced in a first refining zone in the refining chamber so as to produce an upwardly mobile reduced viscosity portion of the viscous liquid layer. Heat is introduced into the viscous liquid layer from above the viscous liquid layer in a second refining zone in the refining chamber downstream of the first refining zone, reducing the gaseous inclusions in said viscous liquid layer. Thereafter, the viscous liquid layer having substantially reduced gaseous inclusions is discharged from the refining chamber.