Explosion Risks and Prevention for Liquid Oxygen Storage Tanks

 
Liquid oxygen tanks are widely used in industrial and research applications, but they come with potential explosion risks during storage and handling. Due to the high reactivity and volatility of liquid oxygen, improper handling can lead to severe safety incidents. Understanding the causes of explosions in liquid oxygen tanks and implementing effective preventive measures is crucial for ensuring the safety of personnel and equipment. This article will delve into the primary causes of explosions in liquid oxygen tanks and provide specific preventive measures to help industry professionals and managers better manage and mitigate these risks.

Causes of Explosions in Liquid Oxygen Tanks

 
Understanding the causes of explosions in liquid oxygen tanks is essential for developing effective safety measures. Liquid oxygen is a substance with high volatility and strong oxidizing properties, requiring special attention during storage and handling. The main causes of explosions are as follows.

1. Volatility of Liquid Oxygen and Tank Overfill

 
Liquid oxygen has high volatility at room temperature and gradually turns into gas inside the tank. If the tank is overfilled with liquid oxygen, the gas generated cannot be effectively released, leading to a rapid increase in internal pressure. If this pressure exceeds the tank's design capacity, it can cause an explosion. To prevent this, tanks must have sufficient space to accommodate the evaporated gas.

2. Chemical Reactivity

 
Liquid oxygen is not only physically reactive but also chemically active. It can react violently with various substances, including common materials such as oils and organic compounds. If liquid oxygen comes into contact with these substances in the presence of an open flame or high temperatures, it may trigger a violent reaction, leading to an explosion. Therefore, the environment where liquid oxygen is stored must strictly control temperature and eliminate any sources of ignition.

3. Impact and Collision

 
During storage and transportation, liquid oxygen can become dangerous due to impact or collision. The volatility of liquid oxygen causes pressure to rise within the tank, and external impacts or collisions can cause a sudden increase in pressure, potentially leading to an explosion. The risk of explosion is significantly higher during transportation if mishandling or accidental impacts occur.

Preventive Measures for Liquid Oxygen Tank Explosions

 
Implementing comprehensive and meticulous preventive measures is crucial for effectively preventing explosions in liquid oxygen tanks. These measures cover all stages from filling and transportation to storage and operation, ensuring safe handling and use of liquid oxygen. The following are specific preventive measures.

1. Pre-Filling Preparations

 
Pressure Relief: Before filling liquid oxygen, the remaining pressure in the tank must be relieved to ensure no excessive pressure buildup inside the tank.
Fire Safety Equipment: The filling site should be equipped with sufficient fire-fighting equipment, such as fire extinguishers and fire hydrants, for emergency situations.
Environmental Conditions: Avoid filling during unsafe conditions such as thunderstorms or in the presence of hot work, ensuring a safe environment.

2. During Filling

 
Qualified Personnel: Filling operations must be carried out by qualified personnel with proper operating certificates. Personnel must monitor the tank's pressure continuously during the filling process, ensuring it does not exceed 10 MPa.
Interface Inspection: Regularly check the tank's interfaces to ensure they are securely fastened and leak-free. Address any issues before resuming filling.
Leak Prevention: Conduct a thorough inspection of the equipment and pipelines involved in the filling process to prevent leaks.

3. Transportation and Storage Requirements

 
Loading of Gas Cylinders: Cylinders should be placed horizontally during loading, with consistent head direction and secured to prevent movement during transportation. The loading height should not exceed three layers, or five layers if equipped with railings.
Safety Separation: Cylinders should be transported separately from flammable or explosive materials such as acetylene cylinders, oils, and oily substances. Smoking and open flames are strictly prohibited on transport vehicles, which must be equipped with appropriate fire-fighting and emergency equipment.
Gentle Handling: Avoid rough handling during transportation to prevent dropping, sliding, rolling, or collisions. Use seamless steel cylinders for packaging and ensure caps and shock-absorbing rings are intact.

4. Operation and Maintenance

 
Equipment Selection: Use welded insulated cylinders or cryogenic tankers for safe storage and transportation of liquid oxygen.
Skilled Operation: Operators should be familiar with the storage and handling procedures for liquid oxygen, understand low-temperature liquid handling, and regularly check pressure gauges, level indicators, and safety devices.
Prevent Freezing: Pay special attention to prevent valve freezing, which can cause malfunction, and ensure all equipment operates correctly.

5. Safety Measures

 
Surrounding Environment: No open flames should be present around liquid oxygen tanks, and contact with oily tools must be prevented. The storage area should be free of flammable or explosive materials, with explosion-proof lighting and electrical switches.
Protective Isolation: Install protective barriers around the liquid oxygen tank and clearly mark warning signs to alert personnel to safety precautions.
Prohibition of Certain Operations: Heating, welding, or impacting of liquid oxygen tanks is strictly prohibited to avoid safety incidents.

By understanding the causes of explosions in liquid oxygen tanks and their preventive measures, we can better identify and address potential safety risks. The unique properties of liquid oxygen necessitate rigorous safety measures during storage and handling, including proper filling, transportation, and operational protocols. Through comprehensive safety management and detailed operational steps, the risk of explosions in liquid oxygen tanks can be significantly reduced, ensuring a safe working environment. It is hoped that the guidance provided in this article will assist professionals in implementing these measures effectively, enhancing safety awareness, and ensuring smooth production and research activities.