NO/N2 Gas Cylinder Conditioning via Vacuum Purging
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Solution Overview
Problem
The challenge lies in effectively purging and rinsing gas cylinders to remove residual impurities, particularly oxygen, to ensure the production of NO/N2 gas mixtures that comply with specifications, as the low NO content makes the conditioning process industrially difficult and sensitive to oxygen impurities which can react to form toxic NO2.
Innovation Solution
A process involving multiple stages of vacuuming, purging, and rinsing with nitrogen, including sequential steps of placing containers under vacuum, purging with fluid communication with the atmosphere, and rinsing with nitrogen to achieve a final NO/N2 mixture with an NO content of less than 1200 ppm by volume, ensuring the removal of impurities and maintaining container pressures within specific ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple purging and rinsing steps are implemented to remove oxygen impurities, then the purity of the NO/N2 gas mixture is improved, but the complexity of the conditioning process increases
Solution Approach 1:
The purging and rinsing process is divided into multiple sequential steps (purging with atmosphere communication, placing under vacuum, rinsing with nitrogen) to systematically remove oxygen impurities at different stages, achieving high purity through segmented operational phases
Solution Approach 2:
The conditioning process performs preliminary purging and rinsing operations before the actual filling of the NO/N2 mixture, ensuring that oxygen impurities are removed in advance to prevent toxic NO2 formation during the medical gas preparation
2Reliability
If the container is thoroughly purged and rinsed to remove all oxygen impurities, then the safety of the gas mixture is improved, but the time required for conditioning increases
Solution Approach 1:
The purging and rinsing operations are conducted in continuous sequential steps without interruption, maintaining the useful action of impurity removal throughout the conditioning process to achieve thorough purification while managing time efficiency
Solution Approach 2:
The process utilizes parameter changes in pressure (atmospheric pressure during purging, vacuum during evacuation, pressurized nitrogen during rinsing) to enhance the effectiveness of impurity removal at each stage, improving safety through controlled parameter variations
3Quantity of substance
If the container volume is large to store sufficient gas mixture, then the quantity of gas produced is improved, but the difficulty of effective purging and rinsing increases
Solution Approach 1:
The process employs pneumatic principles using pressurized nitrogen for rinsing and vacuum for evacuation, utilizing gas pressure differentials to effectively flush out oxygen impurities from large container volumes through multiple cycles of pressurization and evacuation
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 process ensures the removal of impurities, particularly oxygen, from gas cylinders, resulting in NO/N2 mixtures that meet specifications, preventing the formation of toxic NO2 and enabling the production of high-quality gas mixtures for medical applications.
Implementation Method 1
stage b) of placing under vacuum
Implementation Method 2
stage c) of rinsing with gas in an inert atmosphere
Implementation Method 3
by mixing nitrogen with said NO/N2 premixture, a final NO/N2 gaseous mixture
Data Source
Figure 1
Figure 2
AI summary
The method for conditioning a NO/N2 gas mixture in at least one container, characterized in that, prior to the introduction of said NO/N2 mixture, said at least one container is subjected to at least one purging step during which the internal volume of the container is brought into fluidic communication with the ambient atmosphere; a vacuuming step during which the internal volume of the container is depressurized; and a gas rinsing step during which an inert gas is introduced into said at least one container. Preferably, the final NO/N2 gas mixture contains an NO content less than or equal to 1200 ppm by volume at a pressure between P1 and 800 bar.