What is a liquid oxygen breathing system? How to ensure the safety of liquid oxygen breathing system

Liquid oxygen respiratory system

Liquid oxygen breathing system is a special oxygen supply system that uses liquid oxygen to provide users with oxygen for breathing. This type of system is typically applied in special environments or specific situations, as described below:
Application scenarios:
Deep sea diving: When divers dive in the deep sea, their liquid oxygen breathing system can provide long-term oxygen supply.
Aerospace: When astronauts walk in space or pilots fly at high altitudes, a liquid oxygen breathing system is necessary.
Military use: Special forces may use liquid oxygen breathing systems during special missions.
High altitude or extreme environment: In oxygen deficient high-altitude areas or extreme environments, the liquid oxygen respiratory system can ensure normal breathing for personnel.
Medical emergency: In medical rescue, especially at disaster sites or field hospitals, the liquid oxygen respiratory system can quickly provide oxygen to patients.
System composition:
Liquid oxygen storage tank: used to store liquid oxygen, usually in a double-layer structure, with a vacuum in the middle to reduce heat loss.
Evaporator: converts liquid oxygen into gaseous oxygen for respiration.
Regulating valve: used to regulate the flow and pressure of gaseous oxygen to ensure stable oxygen supply.
Breathing mask or helmet: Users breathe oxygen through the mask or helmet.
Control system: including monitoring and control system, used to monitor the oxygen supply status and regulate system parameters.
Safety devices: including overvoltage protection, temperature control, and other safety measures to prevent system failures from causing danger.
working principle:
Liquid oxygen evaporation: Liquid oxygen absorbs heat and evaporates in the evaporator, converting into gaseous oxygen.
Pressure regulation: Gaseous oxygen is adjusted to a pressure suitable for breathing through a regulating valve.
Oxygen supply: Gaseous oxygen is transported through pipelines to the user's breathing mask or helmet.
Monitoring and Control: The system monitors the oxygen supply status in real-time to ensure stable and safe oxygen supply.
The design, manufacturing, and use of liquid oxygen breathing systems must strictly comply with relevant safety standards and operating procedures to ensure the safety of users. Due to the hazardous nature of storing and transporting liquid oxygen, this system is typically only used when necessary.

How to ensure the safety of liquid oxygen breathing system?

The safety of liquid oxygen respiratory systems is crucial because liquid oxygen is a low-temperature, high-pressure, and highly flammable substance. Here are some key safety measures and precautions to ensure the safe operation of liquid oxygen breathing systems:
1. Equipment design and manufacturing
High quality materials: Liquid oxygen storage tanks and transport pipelines should use materials that are resistant to low temperatures and corrosion, such as stainless steel or aluminum alloy.
Pressure vessel standards: Liquid oxygen storage tanks should comply with international and national standards, such as ASME (American Society of Mechanical Engineers) standards, to ensure their structural strength and safety.
Thermal insulation performance: Storage tanks should have good thermal insulation performance to reduce the evaporation rate of liquid oxygen and extend storage time.
2. Safety devices
Pressure relief valve: The pressure relief valve installed on the storage tank can automatically open when the internal pressure exceeds the safety limit, preventing danger caused by overpressure.
Temperature sensor: monitors the temperature of liquid oxygen to ensure it remains within a safe range.
Leak detector: Install a leak detector to promptly detect liquid oxygen leaks and prevent accidents from occurring.
Emergency shut-off valve: In the event of a leak or other emergency situation, it can quickly shut off the liquid oxygen supply to prevent the accident from escalating.
3. Operation and maintenance
Professional training: Operators should receive professional training to understand the characteristics and safety operating procedures of liquid oxygen.
Operation Manual: Provide detailed operation manuals, including steps for starting, running, stopping, and emergency handling.
Regular inspection: Conduct a comprehensive inspection of the liquid oxygen breathing system, including storage tanks, vaporizers, regulators, delivery pipelines, and monitoring equipment, to ensure that all components are functioning properly.
Maintenance records: Record the status of each maintenance and inspection for tracking and management purposes.
4. Operating environment
Good ventilation: The environment where liquid oxygen breathing systems are used should maintain good ventilation to avoid oxygen accumulation and increase the risk of fire.
Keep away from fire sources: Liquid oxygen breathing systems should be kept away from open flames, sparks, and other heat sources to prevent fires or explosions.
Anti static measures: Take anti-static measures, such as using anti-static gloves and shoes, to avoid liquid oxygen leakage caused by electrostatic discharge.
5. Operating procedures
Wear protective equipment: Operators should wear appropriate protective equipment such as low-temperature gloves, goggles, and protective clothing to prevent frostbite caused by liquid oxygen contact with the skin or eyes.
Slow operation: When opening and closing valves, they should be operated slowly to avoid the danger caused by sudden pressure changes.
Follow safe distance: When operating liquid oxygen storage tanks, a safe distance should be maintained to avoid direct contact with liquid oxygen.
6. Emergency response
Emergency plan: Develop detailed emergency plans, including measures for handling emergencies such as leaks, fires, and explosions.
Firefighting facilities: equipped with fire extinguishers and other firefighting equipment to ensure rapid extinguishing in case of fire.
Emergency evacuation: Develop an emergency evacuation plan to ensure rapid evacuation of personnel and reduce casualties in the event of an accident.
7. Monitoring and alarm
Real time monitoring: Install oxygen concentration monitors and leak detectors to monitor the concentration and leakage of liquid oxygen in real time.
Alarm system: Set up an alarm system that can promptly issue alerts when abnormal situations are detected, reminding operators to take measures.
8. Regulations and standards
Compliance with regulations: Ensure that the use of liquid oxygen breathing systems complies with relevant national and local regulations and standards, such as the Special Equipment Safety Law, the Regulations on the Safety Management of Hazardous Chemicals, etc.
Certification and Inspection: Regularly conduct third-party certification and inspection of liquid oxygen breathing systems to ensure they meet safety requirements.
Through the above measures, the safety of the liquid oxygen respiratory system can be effectively ensured, the risk of accidents can be reduced, and the life safety of operators and patients can be protected.