Process Chamber Purging Using Thermal Gas Density Control

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Solution Overview

Problem

Existing process chambers require long purging times and high gas consumption to achieve low oxygen concentrations, especially when frequently opened for processing, which is inefficient and costly.

Innovation Solution

A method involving increasing the temperature of the initial gas in the chamber and introducing a colder purging gas to reduce gas density, thereby reducing purging time and gas consumption, while maintaining an inert atmosphere.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the process chamber is purged by introducing inert gas to displace oxygen, then oxygen concentration is reduced, but purging time and gas consumption increase significantly

Engineering Contradiction:
Improveoxygen concentrationVSAvoidpurging time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent changes the temperature parameter of the gas in the process chamber. By heating the gas to increase its pressure and then rapidly cooling it to create a pressure differential, the invention accelerates the purging process. This thermal parameter change enables faster gas exchange without requiring excessive purging time or gas consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic heating and cooling cycles to achieve rapid purging. The gas is heated in cycles to increase pressure, then cooled to create suction effects that draw inert gas through the chamber. This periodic thermal action replaces continuous purging, reducing both time and gas consumption while maintaining effective oxygen removal.

Inventive Principle:
Principle #19Periodic action

2Object-affected harmful factors

If the process chamber is purged by introducing inert gas to displace oxygen, then oxygen concentration is reduced, but the amount of inert gas consumption increases

Engineering Contradiction:
Improveoxygen concentrationVSAvoidinert gas consumption
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent utilizes temperature and pressure parameter changes to optimize inert gas consumption. By heating the gas to increase its pressure and then cooling it to create pressure differentials, the system achieves more efficient gas exchange. This reduces the volume of inert gas needed compared to conventional constant-pressure purging methods.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The periodic heating and cooling cycles create pressure variations that enhance gas exchange efficiency. During heating phases, high-pressure gas is expelled; during cooling phases, inert gas is drawn in more effectively. This periodic action reduces the total amount of inert gas required compared to continuous flow methods.

Inventive Principle:
Principle #19Periodic action

3Productivity

If the process chamber is frequently opened for processing, then product manufacturing is enabled, but purging frequency and gas consumption increase

Engineering Contradiction:
Improveprocessing frequencyVSAvoidinert gas consumption
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent implements rapid thermal cycling that can be quickly executed between processing operations. The heating and cooling cycles are optimized for speed, allowing the chamber to be re-purged efficiently after each opening. This enables frequent processing cycles without proportionally increasing gas consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The periodic thermal action creates a rapid purging mechanism that can be repeatedly applied between processing steps. Each heating-cooling cycle provides a complete purging action, allowing the chamber to be quickly prepared for the next process run. This maintains high productivity while limiting gas consumption per cycle.

Inventive Principle:
Principle #19Periodic 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 method achieves rapid purging with significantly less gas consumption and shorter times, ensuring low oxygen concentrations suitable for additive manufacturing and autoclave processes.

Implementation Method 1

increasing a temperature of a gas initially contained in the process chamber

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

increasing a temperature of a gas initially contained in the process chamber... which is below 0 °C

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3476973B1Process chamber and method for purging the same
Publication Date: 2026.04.22 LAIR LIQUIDE SA POUR LE TUDE ETLEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP3476973B1 patent drawingFigure 1~2
  • EP3476973B1 patent drawingFigure 3~4

AI summary

Method for purging a process chamber (1) comprising at least the following steps: a) increasing a temperature of a gas initially contained in the process chamber (1) at least to a first temperature, b) introducing a purging gas, which is at a second temperature, into the process chamber (1), wherein the first temperature is higher than the second temperature. With the provided a method process chamber (1) can be purged with a purging gas such as nitrogen and/or argon at a particularly low consumption of the purging gas and/or with a particularly short purging time. This can be achieved by increasing the temperature of the gas initially contained within the process chamber (1) prior to purging, thus reducing the density of this gas.