Key Points for Safe Operation of Liquid Oxygen Tanks
In the operation of liquid oxygen tanks, a profound understanding of the process and equipment is the cornerstone of safety. Liquid oxygen, being a highly pressurized and flammable gas, poses numerous inherent risks during its usage, necessitating that operators possess comprehensive technical competence. The following discourse will delve into the key points of operating liquid oxygen tanks to ensure the safe and smooth progression of production processes.
1. Comprehensive Knowledge and Inspection
Operators must possess in-depth knowledge of the process and equipment. They need to understand the working principles of liquid oxygen tanks, operational procedures, and the functioning of safety equipment. Regular inspections of pressure gauges, level indicators, and all safety devices are imperative to ensure equipment operates in a safe and reliable manner, particularly guarding against the risk of valve freezing and jamming.
2. Maintaining Internal Pressure and Sealing
The gas used for sealing should be dry nitrogen, and the sealing must remain uninterrupted to maintain internal pressure within the safe range, typically above 0.01 MPa.
3. Control of Operating Pressure
Over-pressurizing liquid oxygen tanks is strictly prohibited. Operators must conduct weekly tests on the acetylene content in liquid oxygen, promptly releasing excess oxygen if it surpasses 0.1 ppmm. This measure aims to prevent hazardous situations arising from excessive pressure in the liquid oxygen tank.
4. Appropriate Control of Liquid Level
Liquid oxygen tanks should not be filled to capacity, and a certain gas space must be retained. According to regulations, liquid oxygen should not exceed 95% of the geometric volume of the tank, and the liquid level should not exceed 90%. This design aims to prevent pressure elevation caused by temperature fluctuations leading to liquid oxygen expansion.
5. Regular Inspection of Safety Devices
Pressure gauges, vacuum gauges, level indicators, alarm systems, and safety valves must undergo regular calibration to ensure their accuracy, sensitivity, reliability, and effectiveness, providing timely safety assurance.
6. Optimal Vaporizer Control
The water level in the liquid oxygen tank vaporizer should be maintained above the prescribed value, with water temperature generally controlled at around 60°C. Vaporizers should be equipped with low outlet temperature alarms and liquid oxygen pump interlock parking protection devices to ensure liquid oxygen remains in a safe state.
7. Thawing Procedures
When equipment, pipelines, or valves freeze, thawing should be done using hot nitrogen or air at 70-80°C. Methods such as knocking, heating with fire, or electric heating are strictly prohibited to prevent equipment damage or safety accidents.
8. Prevention of Leakage and Frostbite
Strict measures must be taken to prevent liquid oxygen leakage and skin frostbite upon contact with liquid oxygen. Extra caution is required in handling low-temperature liquids to ensure the safety of operators.
9. Fire and Explosion Prevention
High temperatures and heat sources must be kept away from liquid oxygen tanks and low-temperature liquid pipelines, and flammable materials must be prohibited from proximity. Open flames or sparks are not allowed within a radius of 30mm from the liquid oxygen tank; only explosion-proof electrical equipment must be used.
In conclusion, the safe operation of liquid oxygen tanks is crucial for ensuring the smooth progress of production processes and the health and safety of employees. We will strictly adhere to the above regulations, enhance employee training, and promote safety awareness to ensure that liquid oxygen tanks maximize efficiency in production while safeguarding the safety of personnel and equipment.