ETO Recovery System Using Pressure and Phase Transitions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for recycling ethylene oxide (ETO) gas in sterilization processes are inefficient, as high concentration ETO is not recyclable, leading to increased costs and safety concerns due to its flammability and toxicity, and existing systems are not designed to handle the higher pressures required for recycling low concentration mixtures, resulting in reduced sterilization effectiveness and increased equipment costs.
Innovation Solution
A system and method that involves a pressure reducing valve, condensers, and a separation pump to recover ETO from waste gas mixtures by adjusting pressures and temperatures to condense and separate ETO from nitrogen and water vapor, allowing for the reuse of ETO while minimizing equipment size and cooling energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high concentration ETO gas is used for sterilization, then sterilization effectiveness is improved, but recyclability deteriorates and safety risks increase
Solution Approach 1:
The patent changes the concentration parameter of ETO gas from high to low, and changes the pressure parameter from atmospheric to above atmospheric. This allows the sterilization process to use low concentration ETO at higher pressures, making the gas recyclable while maintaining sterilization effectiveness. The system recovers and concentrates ETO from the spent gas for reuse.
Solution Approach 2:
The patent utilizes phase transitions of ETO gas during the recovery process. The spent ETO gas is cooled to condense the ETO into liquid form for collection and storage, then vaporized again for reuse in the sterilization chamber. This phase change mechanism enables efficient recovery and recycling of the sterilant.
2Adaptability or versatility
If low concentration ETO mixtures are used at higher pressures, then recyclability is improved, but sterilization effectiveness deteriorates
Solution Approach 1:
The patent applies parameter changes by operating the sterilization chamber at above atmospheric pressures with low concentration ETO mixtures. The recovery system then concentrates the ETO from the spent gas and returns it to the chamber, maintaining effective sterilization concentration through recycling rather than using high initial concentrations.
Solution Approach 2:
The patent implements continuous recycling of ETO gas through the recovery system. The spent gas is continuously processed to recover ETO, which is then continuously supplied back to the sterilization chamber. This continuous cycle maintains effective ETO concentration without requiring high initial concentrations, enabling both recyclability and sterilization effectiveness.
3Productivity
If multiple sterilization chambers are coupled together, then productivity is improved, but peak flow rate of waste gas increases
Solution Approach 1:
The patent merges the waste gas streams from multiple sterilization chambers into a single recovery system. The combined waste gas is processed together through the condensation and collection system, allowing the recovery apparatus to handle the total flow from all chambers simultaneously. This integrated approach maintains high productivity while managing the peak flow rate through a unified recovery process.
4Adaptability or versatility
If larger sized recovery apparatus is used to handle greater waste gas flow, then recyclability is improved, but capital cost and operating cost increase
Solution Approach 1:
The patent utilizes phase transitions (condensation of ETO from gas to liquid) to efficiently separate and recover the sterilant from the waste gas stream. This physical separation mechanism is highly effective and requires relatively simple equipment compared to chemical separation methods, reducing both capital cost and system complexity while maintaining high recyclability.
Solution Approach 2:
The recovery system is designed to operate passively utilizing the natural condensation of ETO when cooled. The system leverages the inherent properties of ETO to condense and collect it without requiring complex active separation processes, reducing equipment complexity and operating costs while achieving effective recycling.
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 recovers high-purity ETO for reuse, reducing waste and operational costs, while ensuring safety by maintaining pressures below atmospheric levels, thus enhancing sterilization effectiveness and minimizing the risk of explosions.
Implementation Method 1
a pressure reducing valve for reducing a pressure of a waste gas from one or more sterilization chambers to a first predefined pressure
Implementation Method 2
A first condenser may be configured to receive the gaseous mixture via the pressure reducing valve, and to cool the gaseous mixture to a temperature below a boiling point temperature and above a freezing point temperature of the water vapor at the first predefined pressure
Implementation Method 3
A separation pump coupled to the first tank may raise the pressure of the gaseous mixture to a second predefined pressure
Implementation Method 4
A second condenser may be configured to receive the gaseous mixture from the separation pump, to cool the gaseous mixture to a temperature below a boiling point temperature and above a freezing point temperature of the sterilization agent at the second predefined pressure causing the sterilization agent to condense into a liquid
Data Source
AI summary
A system and method for recovering a sterilization agent from waste gaseous mixture, comprising a gas separator to wash waste gas comprising a gaseous mixture of a sterilization agent, insert dilution gases, and water vapor, from plurality sterilization chambers, with water, thereby producing a water-gaseous sterilization agent mixture collected at bottom section of the gas separator, and inert dilution gases exhausted at top section of the gas separator; a pressure reducing valve; a first tank or gas evaporator to produce gaseous sterilization agent and water vapor; a first condenser to produce condensed water vapor and separate the gaseous sterilization agent from the condensed water vapor; a water tank to receive the condensed water vapor; a separation pump for raising pressure of the gaseous sterilization agent; a second condenser to cool the gaseous sterilization agent causing the sterilization agent to condense into liquid; and a second tank for storing the liquid sterilization agent.