Tapered Burner Shield for Soot Deposition

Solution Overview

Problem

Existing burner shields for soot deposition burners suffer from soot buildup, which can lead to soot aggregation and detachment, causing defects in optical fiber preforms during the soot deposition process.

Innovation Solution

A burner shield with a generally cylindrical first wall disposed radially outwardly from the soot deposition burner, featuring a tapered design with a thicker base end and a thinner shield face, and an optional second cylindrical wall creating an annular space for gas flow, reducing soot deposition on the shield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a burner shield is used to guide the flame during soot deposition, then flame guidance and soot deposition efficiency are improved, but soot buildup on the shield occurs leading to aggregation and detachment defects

Engineering Contradiction:

Improvesoot deposition efficiencyVSAvoidsoot buildup and detachment

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The burner shield employs a tapered wall structure where the wall thickness varies along its length, being thickest at the base and progressively thinner toward the flame-facing surface. This non-uniform thickness distribution creates different local properties: the thicker base provides structural support while the thinner flame-facing surface minimizes soot accumulation and facilitates soot slide-off, thus resolving the contradiction between maintaining shield integrity and preventing soot buildup.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of attempting to prevent soot deposition on the shield surface through conventional means, the invention inverts the approach by designing a surface that actively promotes soot removal. The tapered geometry creates a surface where soot naturally accumulates and then slides off due to gravity and surface angle, transforming the shield from a passive structure that collects soot into an active component that facilitates soot removal.

Inventive Principle:

Principle #13The other way round (Inversion)

2Strength

If the burner shield wall is made thicker to provide structural support, then structural integrity is improved, but soot buildup increases leading to aggregation issues

Engineering Contradiction:

Improvestructural integrityVSAvoidsoot aggregation

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The burner shield employs a tapered wall structure where the wall thickness varies along its length, being thickest at the base and progressively thinner toward the flame-facing surface. This non-uniform thickness distribution creates different local properties: the thicker base provides structural support while the thinner flame-facing surface minimizes soot accumulation and facilitates soot slide-off, thus resolving the contradiction between maintaining shield integrity and preventing soot buildup.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If a uniform thickness design is used for the burner shield, then manufacturing simplicity is improved, but soot deposition control is worsened

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidsoot deposition control

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The burner shield employs a tapered wall structure where the wall thickness varies along its length, being thickest at the base and progressively thinner toward the flame-facing surface. This non-uniform thickness distribution creates different local properties: the thicker base provides structural support while the thinner flame-facing surface minimizes soot accumulation and facilitates soot slide-off, thus resolving the contradiction between maintaining shield integrity and preventing soot buildup.

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

The solution minimizes soot buildup on the burner shield, preventing detachment and resulting in higher quality optical fiber preforms with fewer defects, enhancing soot deposition efficiency and refractive index profile control.

Implementation Method 1

a gas flow is permitted to flow through the annular space in a direction generally perpendicular to and outward from the first surface of the burner support

Methodology Applied

Scientific EffectGas flow: Convection

Implementation Method 2

Precursors for the production of a soot material are supplied to the flame. The precursors are reacted in the flame to form the soot material.

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS9540272B2Burner shield to reduce soot buildup

Publication Date: 2017.01.10 CORNING INC

AI summary

A soot deposition burner assembly, having at least one burner including a burner face on a first surface of a burner support. The burner produces a flame which extends generally perpendicularly to the first surface. A burner shield includes a first wall extending generally perpendicularly from the first surface surrounding the burner face. The burner shield has a base end with a first surface area facing toward the first surface and a shield face with a second surface area facing away from the first surface. To reduce the buildup of soot material, the second surface area is smaller than the first surface area, and the wall thickness is less at the shield face than the base end. Additionally, air can be directed along an exterior surface of the first wall from the base end toward the shield face to further reduce soot buildup.