Glass-Melting Device with Vacuum Tank for Bubble Removal

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Solution Overview

Problem

The existing methods for producing glass fibers, such as the direct melt and marble melt processes, often result in the generation of bubbles during the melting process, which can lead to reduced mechanical strength and electrical insulation properties of the spun glass fibers, and current solutions like adding clarifying agents or modifying furnace outlets are either costly or ineffective.

Innovation Solution

A glass-melting device with a first tank under reduced pressure, a conduit, and a second tank at atmospheric pressure, equipped with a bushing having multiple nozzles, where the temperature of each component can be adjusted separately to remove bubbles from the molten glass, thereby reducing their inclusion in the spun fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If clarifying agents are added to glass raw materials to reduce bubbles, then bubble inclusion is reduced, but production cost increases and environmental harm occurs

Engineering Contradiction:
Improvebubble inclusionVSAvoidproduction cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent applies vacuum atmosphere (inert environment) in the melting furnace to prevent bubble generation and promote bubble removal. By maintaining a vacuum environment during melting, volatile components are prevented from forming bubbles, and existing bubbles rise and escape, eliminating the need for clarifying agents and their associated costs and environmental harm.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Object-affected harmful factors

If a valve is attached to the outlet of the melting furnace to reduce bubbles, then bubble inclusion is reduced, but the method is ineffective for already-formed bubbles

Engineering Contradiction:
Improvebubble inclusionVSAvoideffectiveness
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies preliminary action by maintaining a vacuum atmosphere during the entire melting process to prevent bubble formation in the first place. Additionally, the vacuum environment continuously acts on the molten glass to promote bubble rise and escape before the glass is discharged, ensuring that bubbles are removed proactively rather than reactively at the outlet.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If multiple heating zones with separate temperature control are implemented, then bubble generation from reboiling is suppressed, but device complexity increases

Engineering Contradiction:
Improvebubble generationVSAvoidtemperature control system
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent divides the melting furnace into multiple heating zones (first heating zone, second heating zone, third heating zone) with independent temperature control. Each zone maintains different temperature levels appropriate for its function: the first zone for initial melting, the second for maintaining molten state, and the third for preheating. This segmentation allows precise temperature management to prevent reboiling and bubble generation while keeping each zone's control system relatively simple.

Inventive Principle:
Principle #1Segmentation

4Stability of the object's composition

If the conduit is heated to prevent glass solidification, then glass flow is maintained, but energy consumption increases

Engineering Contradiction:
Improveglass flow stateVSAvoidenergy consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by heating only specific sections of the conduit where temperature drop and solidification risk occur, rather than heating the entire conduit uniformly. The heating elements are positioned at critical locations along the conduit path, providing localized thermal energy to maintain glass flow state only where necessary, thereby minimizing overall energy consumption while ensuring glass remains molten throughout the discharge process.

Inventive Principle:
Principle #3Local quality

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 effectively reduces the inclusion of bubbles in glass fibers, enhancing their mechanical strength and electrical insulation properties without the environmental and cost concerns associated with previous methods.

Implementation Method 1

a first sucking device for exposing the first glass-melting tank in a reduced-pressure atmosphere

Methodology Applied
Scientific EffectReduced-pressure atmosphere: Vacuum

Implementation Method 2

each of the first glass-melting tank, the conduit, the second glass-melting tank, and the bushing have heating means for adjusting the temperature separately

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

an electrode part be provided on an upper portion of the conduit or the first melting tank, and a lower portion of the conduit. It is also preferable that the conduit be heated when a current is applied

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP3214053B1Glass-melting device for producing glass fiber and method for producing glass fiber
Publication Date: 2020.10.21 NITTO BOSEKI CO LTD
  • EP3214053B1 patent drawingFigure 1
  • EP3214053B1 patent drawingFigure 2
  • EP3214053B1 patent drawingFigure 3(a)~3(b)

AI summary

A glass-melting device for producing glass fibers capable effectively reducing inclusion of bubbles into glass fibers to be spun, and a method for producing glass fibers using the same are provided. A glass-melting device 100 for producing glass fibers comprises: a first glass-melting tank 12; a conduit 14 extending downward from the first glass-melting tank 12; a sucking device 18 for exposing the first glass-melting tank 12 to a reduced-pressure atmosphere; a second glass-melting tank 20 provided on a lower portion of the conduit 14 and exposed to an atmospheric-pressure atmosphere; and a bushing 22 provided at a bottom portion of the second glass-melting tank 20 and equipped with a number of nozzles 22a.