Previously, it was believed that the cause of the explosion in the fractionation tower was caused by acetylene. In the explosion-proof system, liquid air and liquid oxygen adsorbers were installed, and the efficiency of adsorbing acetylene could reach about 98%. After years of practice and research abroad, it has been found that in addition to acetylene, there are also saturated and unsaturated hydrocarbons - hydrocarbons, such as ethane, ethylene, propane, propylene, etc. - enriched in liquid oxygen as explosive sources. These substances can also be partially adsorbed in the adsorber, but the adsorption efficiency is only 60% to 65%. Due to their low partial pressure in liquid oxygen, the amount discharged together with gas oxygen is very small (except for methane), and the remaining will gradually concentrate in liquid oxygen. Once the concentration reaches the explosion limit, it is dangerous.
In order to avoid an increase in hydrocarbon concentration in liquid oxygen, according to material balance, it is necessary to extract a portion of liquid oxygen from the main cooling system and extract a portion of hydrocarbons from the main cooling system. The minimum amount of extracted liquid oxygen is equivalent to 1% of the gas oxygen production before further gasification. It is also stipulated to raise the liquid oxygen surface to avoid dry evaporation of liquid oxygen (without liquid oxygen at the outlet of the evaporation pipe), prevent hydrocarbons from adhering to the pipe wall, and increase the safety of the equipment. This measure has also been adopted in the domestic full low-pressure air separation process.
DEAR Company has technological advantages and engineering technicians with practical equipment operation experience operate and manage customers' equipment to ensure long-term, stable, and safe operation.
