CCTV reported that according to the Fire Department of the Ministry of Public Security, the accident in the production workshop of Baoyuan Fengqin Industry Co., Ltd. in Jilin was caused by an explosion caused by liquid ammonia leak. What is liquid ammonia? What do poultry companies do with it? Why did the liquid ammonia explosion cause so many casualties? How to prevent the harm caused by liquid ammonia? The reporter interviewed Dong Jinshi, an expert in environmental chemistry, and Zhang Xu, a staff member of the special service detachment of the Beijing Public Security Fire Brigade.

cold chain

Production of liquid ammonia for general use

It is understood that large-scale poultry slaughterhouses are all cold chain production, slaughterhouses and partitioning workshops are closed and operated at low temperature, so liquid ammonia is needed for refrigeration. Generally, large-scale slaughterhouses will have several tons or more of liquid ammonia. Liquid ammonia is corrosive and volatile easily, so the incidence of chemical accidents is quite high.

Dong Jinshi told reporters that liquid ammonia, also known as anhydrous ammonia, is a colorless liquid, it is an industrial refrigerant, through the pipeline can reduce the temperature of cold storage, so that chicken and other products can be preserved below - 18 degrees Celsius.

liquid ammonia

The explosion is more harmful.

Zhang Xu, staff member of the special service detachment of Beijing Public Security Fire Brigade, said that liquid ammonia is a toxic gas and can react violently with fluorine and chlorine. When ammonia is mixed with air in a certain proportion, it can cause explosion when exposed to open fire. In terms of combustion and explosion characteristics, ammonia is a combustible gas at room temperature, but it is difficult to ignite. The explosion limit is 16%-25%, and the most easily ignited concentration is 17%. The maximum explosion pressure is 22.5%.

According to Dong Jinshi, ammonia, a chemical substance, is a gas at room temperature and pressure; it becomes liquid ammonia at high pressure or low temperature, and its boiling point is - 33.5 C. High temperature can easily cause explosion. It takes a lot of pressure to keep ammonia in liquid state. When the pressure is very high, once the impact from outside or the temperature is too high, the harm of liquid ammonia explosion will be greater. At present, there are different opinions about the cause of the accident. If liquid ammonia explosion occurs, the reason is either high temperature or high pressure.

As ammonia is a toxic and harmful gas, it can stimulate nervous system, respiratory tract and gastric mucosa, which may even lead to asphyxia and death. Therefore, after the leakage accident, people must not wait in the downdraft port, can be transferred to the updraft port, away from the source of the explosion.

Source: Beijing Times