Plasma Torch Liquid Shield Regulation for Stable Cut Quality

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Plasma arc cutting systems experience significant variations in cut quality due to changes in shield fluid flow rate caused by elevation changes of the fluid selection console, leading to inconsistent cutting results.

Innovation Solution

A liquid injection regulation component with metering and swirl holes is introduced to stabilize the shield fluid flow rate, reducing pressure variations and ensuring consistent cut quality by creating a constant atomized mist pressure, making the system less responsive to elevation changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If water is used as shield fluid in plasma arc cutting, then cooling and shielding functions are achieved, but cut quality varies significantly with elevation changes of the fluid selection console

Engineering Contradiction:
Improvecut quality consistencyVSAvoidsensitivity to elevation changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the pressure parameter of the shield fluid system by introducing a pressurization mechanism that maintains constant pressure regardless of elevation changes. This allows the system to deliver consistent flow rates to the torch at any elevation, resolving the contradiction between reliable cut quality and sensitivity to elevation changes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback control system using flow sensors and pressure sensors that monitor shield fluid delivery and automatically adjust pressurization to maintain consistent flow rates. This feedback mechanism ensures cut quality remains reliable while compensating for elevation variations in real-time

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If fluid flow rate is increased to improve shielding, then cut quality improves, but system complexity increases due to need for precise flow control

Engineering Contradiction:
Improvecut qualityVSAvoidflow control system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs self-regulating flow control mechanisms where the system automatically maintains optimal shield fluid flow rates through inherent pressure compensation and feedback control, eliminating the need for complex manual adjustment systems while ensuring precise cut quality

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical flow control valves with a pressurization-based system that uses electronic sensors and automated pressure regulation, reducing mechanical complexity while maintaining or improving flow control precision for consistent cut quality

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 ensures reliable and repeatable cuts regardless of the fluid selection console's elevation relative to the torch, maintaining consistent cut quality by desensitizing the plasma system to external pressure changes.

Implementation Method 1

a larger fluid set pressure (e.g., 25-30 psi (1.72 - 2.07 bar)) can be applied in the fluid selection module (e.g., the Gas Connect module 104 shown and described below in Figure 1), which can in turn be substantially decreased across the metering holes. In some embodiments, the pressure drop is so large that it advantageously makes the system essentially unresponsive to small pressure changes caused by elevation differences between the fluid selection console and the metering console.

Methodology Applied
Scientific EffectAtomization: Aerosol

Implementation Method 2

Plasma arc torches are widely used in the cutting and marking of materials. A plasma torch generally includes an electrode and a nozzle having a central exit orifice mounted within a torch body, electrical connections, passages for cooling fluids (e.g., water), and passages for arc control fluids (e.g., plasma gas).

Methodology Applied
Scientific EffectPlasma shielding: Absorption (EM radiation)

Implementation Method 3

The torch produces a plasma arc, a constricted ionized jet of a gas with high temperature and high momentum.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

The torch produces a plasma arc, a constricted ionized jet of a gas with high temperature and high momentum.

Methodology Applied
Scientific EffectPlasma: Plasma

Data Source

PatentEP3332615B1Improved plasma arc cutting systems, consumables and operational methods
Publication Date: 2022.04.13 HYPERTHERM INC
  • EP3332615B1 patent drawingFigure 1
  • EP3332615B1 patent drawingFigure 2A
  • EP3332615B1 patent drawingFigure 2B~2C

AI summary

The invention features methods and apparatuses for regulating a shielding liquid in a plasma torch. A liquid-injection shield for a plasma torch includes a body having an exterior surface and an interior surface and a liquid injection regulation component circumferentially disposed within and in direct contact with the interior surface of the body. The liquid injection regulation component and the interior surface of the body define a chamber. The liquid injection regulation component also defines a first set of ports sized to regulate a liquid entering the chamber and a second set of ports oriented to distribute a fluid exiting the chamber.