High Concentration NO2 Generation via Plasma Circulation

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Solution Overview

Problem

Current sterilization methods for medical instruments, such as high-pressure steam and ethylene oxide gas sterilization, have limitations including temperature constraints, toxicity, and safety concerns, while existing nitrogen oxide methods produce low concentrations of NO2, inadequate for deep sterilization of medical instruments.

Innovation Solution

A high concentration NO2 generating system using a circulating path with a plasma generator, pressure device, and flow resistive components to produce NO2 concentrations of 500 ppm or above from ambient air, utilizing a plasma generator to convert nitrogen and oxygen into NO2, with a concentration measuring system to ensure precise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If single pass plasma treatment is used to generate nitrogen oxide, then the sterilization process can be performed at moderate temperature, but the concentration of NO2 is too low (several ppm) to achieve high level sterilization

Engineering Contradiction:
Improvesterilization temperatureVSAvoidNO2 concentration
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The patent implements a circulating path that continuously recycles and re-treats the gas mixture through the plasma generator multiple times. This continuous circulation allows progressive accumulation of NO2 concentration with each pass, transforming the single-pass low-concentration process into a multi-pass high-concentration process while maintaining moderate temperatures throughout the system.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system employs periodic plasma treatment cycles where the gas mixture is repeatedly subjected to plasma discharge in the circulating path. Each circulation cycle represents a periodic action that incrementally increases NO2 concentration, allowing the system to achieve high concentrations through repeated intermittent treatment rather than continuous single-pass processing.

Inventive Principle:
Principle #19Periodic action

2Ease of manufacture

If high concentration ozone is used for sterilization, then the generation and decomposition are simple, but high concentration ozone is explosive and gives substantial damage to plastics

Engineering Contradiction:
Improvesimplicity of generation and decompositionVSAvoidexplosion risk and plastic damage
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using nitrogen and oxygen plasma to generate NO2 instead of using ozone. This parameter change substitutes a different chemical substance with similar sterilization capabilities but fundamentally different safety characteristics, eliminating explosion risks and plastic damage while maintaining ease of generation through plasma treatment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system converts the potentially harmful high-energy plasma discharge into a beneficial sterilization agent (NO2) by controlling the plasma treatment in a circulating path. The plasma energy that could potentially cause damage is instead harnessed to create nitrogen oxides from nitrogen and oxygen, transforming a harmful factor into a useful sterilization mechanism that is both effective and safe.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Temperature

If ethylene oxide gas is used for sterilization, then it can be used for plastics at lower temperature, but it has toxicity and explosion risk requiring secure storage and careful handling

Engineering Contradiction:
Improvesterilization temperatureVSAvoidsafety and handling reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The system generates NO2 on-demand through plasma treatment of nitrogen and oxygen in the circulating path, eliminating the need for external gas cylinders or storage systems. The sterilization agent is produced self-sufficiently within the system, removing all associated storage, handling, and safety concerns while maintaining low-temperature operation suitable for plastics.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts and eliminates the hazardous storage and handling components (gas cylinders, pressure regulators, leakage detection systems) by generating the sterilization agent directly within the system. Only the essential plasma generation and circulation components remain, simplifying the system while improving safety and reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If nitrogen oxide is generated on demand without circulation, then safety is improved by eliminating storage, but the concentration remains too low for deep sterilization of medical instruments

Engineering Contradiction:
Improvesafety by eliminating storageVSAvoidNO2 concentration for deep sterilization
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The circulating path enables continuous recycling of the gas mixture through the plasma generator, maintaining continuous NO2 generation without interruption. This continuous action allows concentration to build up progressively with each circulation cycle, achieving high concentrations suitable for deep sterilization while preserving the safety advantage of on-demand generation without storage.

Inventive Principle:
Principle #20Continuity of useful 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 system effectively generates high concentration NO2 for enhanced sterilization of medical instruments, overcoming previous limitations by producing NO2 concentrations suitable for deep sterilization without the need for hazardous gas storage or handling, ensuring safety and efficiency.

Implementation Method 1

utilizing a plasma generator to convert nitrogen and oxygen into NO2

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

a plasma generator to convert nitrogen and oxygen into NO2

Methodology Applied
Scientific EffectPlasma generation: Plasma

Data Source

PatentEP2429944B1High concentration no2 generating system and method for generating high concentration no2 using the generating system
Publication Date: 2018.11.07 NOXILIZER INC
  • EP2429944B1 patent drawingFigure 1
  • EP2429944B1 patent drawingFigure 2
  • EP2429944B1 patent drawingFigure 3

AI summary

A high concentration NO2 gas generating system including a circulating path configured by connecting a chamber, a plasma generator, and a circulating means, wherein NO2 is generated by circulating a gas mixture including nitrogen and oxygen in the circulating path is provided. The high concentration NO2 gas generating system provides a high concentration NO2 generating system and the high concentration NO2 generating method using the generating system by which NO2 of high concentration (approximately 500ppm or above) required for a high level of sterilization process in such as sterilization of medical instruments can be simply and selectively obtained. In addition, since indoor air is used as an ingredient, the management of ingredients is simple and highly safe, and the high concentration of NO2 can be simply and selectively prepared on demand.