Vented Nozzle With Longitudinal Plasma Gas Passage

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In high current oxygen plasma arc cutting torches, the short nozzle and electrode life due to excessive heat load and poor swirl ring injection point placement leads to reduced cut performance and increased emitter wear.

Innovation Solution

A nozzle design that allows for a swirl ring injection point close to the electrode face while venting plasma gas to reduce heat load and prevent molten metal entry, featuring a vented nozzle with a plasma gas vent passage and a swirl ring configuration that directs swirling gas flow effectively, enhancing both nozzle and electrode life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If a vented nozzle design is used to reduce heat load and extend nozzle life, then nozzle life is improved, but the swirl ring injection point is forced far from the electrode face, worsening electrode life

Engineering Contradiction:
Improvenozzle lifeVSAvoidelectrode life
Core Design Contradiction:
Duration of action of stationary objectVSDuration of action of moving object

Solution Approach 1:

The patent introduces a longitudinal vent passage through the center of the nozzle, creating a new spatial dimension for plasma gas venting. This central通道 allows the swirl ring to be positioned close to the electrode face while still providing effective venting, as the venting function is achieved through the longitudinal passage rather than requiring lateral distance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The nozzle is segmented into distinct functional zones: the swirl ring injection point close to the electrode face for electrode protection, and the longitudinal vent passage for heat load management. This segmentation allows each component to optimize its position for its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

2Duration of action of moving object

If the swirl ring injection point is moved close to the electrode face to extend electrode life, then electrode life is improved, but the nozzle cannot effectively vent plasma gas, worsening nozzle heat load

Engineering Contradiction:
Improveelectrode lifeVSAvoidnozzle heat load
Core Design Contradiction:
Duration of action of moving objectVSTemperature

Solution Approach 1:

The venting function transitions from a lateral/annular configuration to a longitudinal central passage. This dimensional change allows the swirl ring to occupy the lateral space close to the electrode while the longitudinal passage provides the venting pathway, simultaneously achieving both goals.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The longitudinal vent passage serves multiple functions: it vents plasma gas to reduce heat load on the nozzle, provides structural support for positioning the swirl ring, and maintains plasma gas flow control. This multi-functionality resolves the contradiction by integrating both venting and swirl ring positioning into a unified design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If a long tapered nozzle configuration is used for effective beveling applications, then beveling capability is improved, but the vent passage may be exposed to molten metal ingress, worsening torch reliability

Engineering Contradiction:
Improvebeveling capabilityVSAvoidtorch reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The vent passage is positioned and configured in advance to prevent molten metal ingress before it can cause damage. The longitudinal design and positioning create a protective effect that preemptively blocks the harmful pathway, ensuring torch reliability while maintaining the long tapered configuration for beveling applications.

Inventive Principle:
Principle #10Preliminary 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

The solution extends nozzle and electrode life by improving gas swirl control, reducing emitter wear, and preventing torch failure from molten metal ingress, while allowing for effective beveling applications with a long tapered nozzle configuration.

Implementation Method 1

venting a portion of plasma gas from before the nozzle bore

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Cooling a nozzle wall at the nozzle exit orifice can produce a thin boundary layer of cooled gas

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 3

Cooling a nozzle wall at the nozzle exit orifice can produce a thin boundary layer of cooled gas, which can protect the nozzle and pinch the arc

Methodology Applied
Scientific EffectBoundary layer: Boundary Layer

Implementation Method 4

a swirl ring design with a 'closer' swirl injection location... Moving the swirl injection location closer to the electrode face can enhance electrode life

Methodology Applied
Scientific EffectSwirling flow: Vortex Ring

Data Source

PatentEP2225920B1Nozzle with exposed vent passage, swirl ring and plasma arc torch with said nozzle and swirl ring
Publication Date: 2014.07.23 HYPERTHERM INC
  • EP2225920B1 patent drawingFigure 1
  • EP2225920B1 patent drawingFigure 2
  • EP2225920B1 patent drawingFigure 3

AI summary

A nozzle for a plasma torch can include a body that has an inner surface, an outer surface, a proximal end, and an exit orifice at a distal end. The nozzle can also include a liner surrounded by the inner surface of the body. The liner can include a proximal end and an exit orifice at a distal end adjacent the exit orifice of the body. The nozzle can include at least one vent passage formed in the body. The vent passage can have an inlet formed in the inner surface of the body and an outlet formed in the outer surface of the body. The vent passage can be disposed between the proximal end of the body and the proximal end of the liner. The plasma arc torch can include a configuration that allows for increased electrode life and nozzle life for a vented high current plasma process.