Welding Torch Conical Nozzle for Fume Extraction

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Solution Overview

Problem

Existing welding torch systems do not effectively extract fumes during welding operations, which can be hazardous and require protective gear for welders, necessitating further improvement in fume extraction efficiency.

Innovation Solution

The welding torch system enhances fume extraction by increasing the outlet velocity of shield gas through a conically tapered inner shield gas conduit with a decreasing diameter, promoting a laminar flow and undisturbed gas flow, and optimizing the design of the contact tip holder and outer shell to facilitate efficient fume extraction without interfering with the weld process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the outlet velocity of shield gas is increased to improve fume extraction efficiency, then fume removal effectiveness improves, but the complexity of the shield gas supply system increases

Engineering Contradiction:
Improvefume extraction efficiencyVSAvoidshield gas supply system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the geometric parameters of the inner shield gas conduit by introducing a conical section with a specific taper angle (α) between 5° and 15°. This parameter change accelerates the shield gas flow from the wider section to the narrower outlet section, increasing outlet velocity and improving fume extraction efficiency without requiring additional complex components or system modifications

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a conical (curved/tapered) geometry for the inner shield gas conduit instead of a straight cylindrical shape. This curved/tapered design naturally accelerates the gas flow through geometric convergence, achieving higher outlet velocity and improved fume extraction while maintaining system simplicity

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If a conical tapered inner shield gas conduit is used to increase shield gas outlet velocity, then fume extraction improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improvefume extraction efficiencyVSAvoidconical taper precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent specifies a relatively wide range for the taper angle (α between 5° and 15°), which provides manufacturing flexibility. This parameter range is wide enough to achieve the desired flow acceleration effect while being tolerant of normal manufacturing variations, thereby reducing precision requirements compared to specifying a very narrow angle range

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conical taper is applied only to a specific section (the end portion) of the inner shield gas conduit rather than the entire conduit. This localized application of the tapered geometry concentrates the flow acceleration effect where needed while leaving the rest of the conduit with simpler cylindrical geometry, reducing overall manufacturing complexity and precision requirements

Inventive Principle:
Principle #3Local quality

3Productivity

If the inner shield gas conduit is narrowed towards the outlet to increase gas velocity, then fume extraction improves, but shield gas flow stability may be compromised

Engineering Contradiction:
Improvefume extraction efficiencyVSAvoidshield gas flow stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The gradual conical taper provides a smooth, continuous transition in the conduit cross-section rather than abrupt changes. This smooth curved geometry prevents flow separation and turbulence by gradually accelerating the gas, thereby maintaining flow stability while achieving increased outlet velocity for improved fume extraction

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The conical taper is designed to preemptively establish laminar flow conditions before the gas reaches the outlet. By gradually accelerating the flow through the tapered section, the design prevents the formation of turbulent eddies and flow instabilities that would occur with abrupt narrowing, thus maintaining flow stability while achieving the desired velocity increase

Inventive Principle:
Principle #9Preliminary anti-action

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 design achieves significant fume extraction, potentially eliminating the need for protective gear by maintaining a correct weld quality and ensuring efficient fume removal within a specific flow range, minimizing interference with the shield gas flow.

Implementation Method 1

the inner shield gas conduit has an end portion having an inner surface of which the diameter decreases towards the shield gas outlet

Methodology Applied
Scientific EffectConical tapering effect: Geometry

Implementation Method 2

the inner surface of the end portion is configured for - during operation - generating a substantially undisturbed flow of shield gas or preferably a substantially laminar flow

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Implementation Method 3

a fume extracting assembly operatively connectable to the fume extracting passageway for - during operation - extracting fume and ambient air

Methodology Applied
Scientific EffectFume extraction: Suction

Data Source

PatentEP2842684B1Welding torch system for use in welding or cutting operations, welding torch for use in such a welding torch system
Publication Date: 2019.10.23 NEDERLANDSE ORG VOOR TOEGEPAST NATUURWETENSCHAPPELIJK ONDERZOEK TNO
  • EP2842684B1 patent drawingFigure 1
  • EP2842684B1 patent drawingFigure 2
  • EP2842684B1 patent drawingFigure 3

AI summary

Welding torch system for use in welding or cutting operations during which fume is created. The welding torch system has a welding torch (1) comprising a contact tip holder (2) and a coaxial nozzle (11) comprising an inner shield gas conduit (5) having a shield gas outlet (6) for supplying a shield gas. The inner shield gas conduit (5) surrounds the contact tip holder (2). An outer shell (7) at least partly surrounds said inner shield gas conduit (5). The welding torch system further comprises a shield gas generator and supply unit (12) and a fume extracting assembly (13). The welding torch system is arranged for supplying shield gas through the shield gas outlet at a velocity between about 1.5 m/s and 10 m/s. By operating the fume extracting assembly to generate a flow of between 10 and 100 m 3 /h, preferably a flow of about 55 m 3 /h a reduction in the area of 90%-95% of hazardous fumes can then be realized. A welding torch (1) for use in such a system has an inner shield gas conduit (5) having an end portion with an inner surface of which the diameter decreases towards the shield gas outlet (6). In a method for welding the shield gas is supplied through the shield gas outlet at a velocity between about 1.5 m/s and 10 m/s.