liquid nitrogen container safety and accident

 

1, the external environmental impact

 

① high temperature and pressure

 

Liquid nitrogen is made of compressed air cooling, gasification can be restored to nitrogen. Nitrogen per liter of liquid nitrogen, the temperature increased by 15 ℃, the volume expansion of about 180 times. Explosions occur when the external temperature pressure exceeds the cooling temperature and pressure the tank should withstand.

 

② collision shock

 

Liquid nitrogen container tank has a special shockproof design, in addition to static storage, but also in the state of filling transport. But Tianchi liquid nitrogen tank in the violent collision and vibration, will cause the insulation layer or other parts damaged, the external environment will directly affect the gasification, causing explosion.

 

③ seal bad ventilation

If the use of liquid nitrogen and storage environment is not well ventilated, it will cause indoor nitrogen and nitrogen oxide gas concentration concentration accumulation, reaching the explosion limit, thus triggering an explosion.

Cryogenic Tank YDS-10 Liquid Nitrogen Container

 

2, the quality factor

 

① improper selection

 

Liquid nitrogen tank is generally made of pure aluminum foil and stainless steel cold-rolled steel plate, if the specifications and quality of these main materials do not meet the standard requirements, can not reach the conditions of liquid nitrogen, it is highly likely to explode.

 

② poor insulation

 

Days Chi liquid nitrogen tank from the inside and outside the composition of the gall bladder, the inner wall of the liner wrapped around the body to do more heat, once the reflective material and insulation material off, it will cause the adjacent reflective material in direct contact with the outer bile, so that the inner liquid nitrogen Rapid expansion and gasification until explosion.

 

③ valves, gauges and other accessories aging

 

In the long-term use process, if the nitrogen gas tank on the days of Chi, valves and other accessories do not pay attention to regular inspection and replacement, once the aging of these attachments, it will cause the temperature rise or liquid nitrogen leak, explosion.

20L cryo dewar tank YDS-20 Liquid nitrogen container

 

3, human factors

 

① improper storage and transportation

 

Tianchi liquid nitrogen tank storage types generally can be divided into two kinds of storage tanks and transport tanks. Storage tank is mainly used for indoor storage of liquid nitrogen storage, should not be used for long-distance transport under working conditions.

 

② improper use

 

Long-term use of Tianchi liquid nitrogen tank, if the use of the process did not make regular maintenance inspection and maintenance, the device there will be unsafe hidden dangers, may cause an explosion. In the days of Chi liquid nitrogen tank, if the exhaust valve is not open or open enough degree, after a long period of natural liquid nitrogen evaporation, the pressure inside the cylinder. At this point if there is no safety protection device, the pressure continues to rise, it may lead to the bottom of the pressurized pipe to take over the original defects at the crack. Once the liquid nitrogen leaks into the mezzanine space and gasifies, the pressure in the interlayer rises rapidly, causing the outer cylinder to explode. Some days Chi liquid nitrogen tank operating staff without safety education, relying on the teacher verbal manipulation of skills after the induction operation, safety quality and skills are poor, but also prone to accidents.

 

③ liquid nitrogen leak

 

Long-term liquid nitrogen in the tank can not be properly discharged, or a large number of leakage to the mezzanine space gasification, may also lead to liquid nitrogen container explosion.