Porous Glass Manufacturing Gas Channel Flow Control

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Solution Overview

Problem

Pressure fluctuations in vaporized gas flow rates during the manufacturing of porous glass base materials often result in striae, which are defects in the material due to the overlap of timing in raw material supply or liquid replenishment in vapor generation mechanisms.

Innovation Solution

A manufacturing apparatus with a shared common gas channel and individual gas channels for each deposition apparatus, equipped with flow controllers, steam valves, and adjustable valves to maintain a pressure downstream of 60-95% of the vaporized raw material compound's pressure in the vapor generation mechanism, ensuring stable gas flow and reducing striae formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a common gas channel is shared by multiple vapor generation mechanisms, then equipment complexity is reduced and cost is lowered, but pressure fluctuations occur due to overlapping timing of manufacturing or liquid replenishment

Engineering Contradiction:
Improvegas channel configurationVSAvoidgas flow stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The gas channel system is segmented into common gas channels shared by multiple vapor generation mechanisms and individual gas channels dedicated to each deposition apparatus. This segmentation allows the common channel to maintain simplicity while individual channels provide isolated control paths that prevent pressure fluctuations from affecting other apparatuses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Individual gas channels act as intermediary pathways between the common gas channel and each deposition apparatus. These intermediary channels isolate pressure fluctuations caused by liquid replenishment or overlapping manufacturing timing, preventing them from propagating through the common channel to affect other apparatuses.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If individual gas channels with flow controllers are provided for each deposition apparatus, then manufacturing precision is improved by suppressing striae, but device complexity increases

Engineering Contradiction:
Improveporous glass base material qualityVSAvoidgas channel configuration
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The gas supply system is divided into common channels for shared resources and individual channels for each deposition apparatus, with flow controllers installed in the individual channels. This segmentation enables precise control of gas flow to each apparatus without requiring complete system redesign, thus improving manufacturing precision while limiting complexity increase to only the necessary control components.

Inventive Principle:
Principle #1Segmentation

3Reliability

If pressure control valves are installed in individual gas channels, then gas flow stability is improved to prevent striae, but the number of components and system complexity increases

Engineering Contradiction:
Improvevaporized gas flow rate stabilityVSAvoidvalve and control component quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Pressure control valves and flow controllers are installed locally in individual gas channels only where needed at each deposition apparatus, rather than controlling the entire common gas channel system centrally. This local quality approach provides precise pressure and flow control at each apparatus while minimizing the total number of control components and avoiding unnecessary system-wide complexity.

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 configuration effectively suppresses striae in porous glass base materials by maintaining consistent vaporized gas flow rates, even with fluctuations in pressure, thereby ensuring the production of high-quality materials without significant investment in new equipment.

Implementation Method 1

at least one vapor generation mechanism that vaporizes the raw material compounds in the storage container

Methodology Applied
Scientific EffectVaporization: Evaporation

Implementation Method 2

generate raw material particles from vaporized raw material compounds in an oxyhydrogen flame

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3988508B1Manufacturing apparatus and manufacturing method of porous glass base material
Publication Date: 2024.08.14 SHIN ETSU CHEMICAL CO LTD
  • EP3988508B1 patent drawingFigure 1

AI summary

An apparatus for manufacturing a porous glass base material and a manufacturing method that can suppress striae caused by fluctuations in vaporized gas flow rate are provided. A manufacturing apparatus of porous glass base material includes a plurality of deposition apparatuses that manufacture a porous glass base material by generating raw material particles from vaporized raw material compounds in an oxyhydrogen flame, and then depositing the generated raw material particles on a rotating starting material. The manufacturing apparatus includes at least one storage container that stores liquid raw material compounds for each compound, at least one vapor generation mechanism that vaporizes the raw material compounds in the storage container, and at least one gas channel that supplies the raw material compounds vaporized by the vapor generation mechanism to a plurality of deposition apparatuses. The gas channel includes a common gas channel that is shared to supply vaporized raw material compounds to the plurality of deposition apparatuses, and a plurality of individual gas channels that are branched off from the common gas channel to supply vaporized raw material compounds to each of the deposition apparatuses individually. Each of the plurality of individual gas channels has a flow controller that controls the flow rate of the vaporized raw material compound, a steam valve that controls the on/off (opening/shutting) of the vaporized raw material compound distribution, and a valve that is provided upstream from the flow controller and can adjust flow channel cross-section area.