Plasma Torch Post Arc Cooling Gas Duration Control

Solution Overview

Problem

Existing plasma cutting systems inefficiently control post arc cooling gas flow, leading to either inadequate or excessive cooling, which affects the life cycle of the plasma torch tip assembly and wastefully consumes cooling gas.

Innovation Solution

A dynamically controlled plasma cutting system that uses a controller to monitor plasma arc parameters at termination and adjust the duration of post arc gas flow based on operating conditions, ensuring optimal cooling without unnecessary gas consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If post flow cooling is maintained for a preset duration, then the plasma torch is cooled after arc termination, but excessive cooling gas is consumed and gas sources are depleted prematurely

Engineering Contradiction:

Improveplasma torch coolingVSAvoidcooling gas consumption

Core Design Contradiction:

TemperatureVSLoss of substance

Solution Approach 1:

The system dynamically adjusts the post flow cooling duration based on real-time monitoring of plasma arc parameters. The controller continuously adapts the cooling gas flow duration to match the actual thermal state of the plasma torch, transitioning from fixed preset duration to variable dynamic control.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller monitors plasma arc parameters during operation and uses this feedback information to determine the appropriate post flow cooling duration. This closed-loop control ensures cooling gas is supplied only as long as needed, preventing both insufficient cooling and excessive gas consumption.

Inventive Principle:

Principle #23Feedback

2Temperature

If post flow cooling is maintained for a preset duration, then cooling is provided to the plasma torch, but the life cycle of the plasma torch tip assembly is reduced due to inadequate cooling

Engineering Contradiction:

Improveplasma torch coolingVSAvoidtip assembly life cycle

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The system dynamically adjusts the post flow cooling duration based on real-time monitoring of plasma arc parameters. The controller continuously adapts the cooling gas flow duration to match the actual thermal state of the plasma torch, transitioning from fixed preset duration to variable dynamic control.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The controller monitors plasma arc parameters during operation and uses this feedback information to determine the appropriate post flow cooling duration. This closed-loop control ensures cooling gas is supplied only as long as needed, preventing both insufficient cooling and excessive gas consumption.

Inventive Principle:

Principle #23Feedback

3Power

If higher power levels are used for plasma cutting, then cutting performance is improved, but more heat is generated requiring longer cooling durations and increased gas consumption

Engineering Contradiction:

Improveplasma cutting powerVSAvoidcooling gas consumption

Core Design Contradiction:

PowerVSLoss of substance

Solution Approach 1:

The controller monitors plasma arc parameters during operation and uses this feedback information to determine the appropriate post flow cooling duration. This closed-loop control ensures cooling gas is supplied only as long as needed, preventing both insufficient cooling and excessive gas consumption.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the cooling gas flow duration parameter dynamically based on the plasma arc parameters monitored during operation. Higher power operations automatically receive longer cooling durations, while lower power operations receive shorter durations, optimizing gas consumption across all operating conditions.

Inventive Principle:

Principle #35Parameter changes

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 system efficiently manages post arc cooling, extending the life of the plasma torch tip assembly and optimizing gas usage by providing the precise amount of cooling necessary, thereby reducing gas depletion and operational inefficiencies.

Implementation Method 1

air is forced past the pilot arc whereby it is heated and ionized to form a plasma jet

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

an electric arc is used for cutting or gouging a workpiece

Methodology Applied

Scientific EffectElectric arc: Electric Arc

Implementation Method 3

air is allowed to continue to flow through the torch for a preset period. The flow of gas through the torch after arc termination is commonly referred to post flow cooling

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 4

The plasma torch must dissipate the residual heat generated during the cutting process

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS7781699B2Plasma torch with post flow control

Publication Date: 2010.08.24 ILLINOIS TOOL WORKS INC

AI summary

A system for the efficient utilization of plasma torch post arc cooling gas includes a controller configured to automatically determine a post arc gas flow duration. The controller monitors a plasma arc parameter associated with a temperature of the plasma torch at arc termination. The controller dynamically determines the duration of post arc gas flow through the torch from the plasma arc parameter.