At present, most of the cooling materials filled in the cooling box of the air separation plant are Pearl sand.
Pearl sand is a particle with small apparent density, which is easy to fly. It will invade the facial features, stimulate the throat and eyes, and even suck in the lung through the respiratory tract. Therefore, wear a protective mask when working.
The fluidity of Pearl sand is very good, and its density is smaller than that of water. People will be drowned and suffocated when they fall into the Pearl sand layer. Therefore, the manhole on the top of the cold box and the loading position should all be installed with 8 ~ 10mm steel bar welded square-shaped safety iron fence to prevent accidents.
When the Pearl sand needs to be removed, the leaking parts are found in the cold box. If it is oxygen leakage, it will increase the oxygen concentration in the cold box, and if it is fire overhaul, explosion accident may occur; if it is nitrogen leakage, the nitrogen concentration in the cold box is very high, which may cause suffocating accident. Therefore, before entering the cold box operation, be sure to analyze in advance whether the oxygen concentration in the cold box is within the normal range (19% ~ 21% ).
In addition, the Pearl sand in the cold box is in low temperature (-50 ~ -80℃), pay attention to take antifreezing measures when extracting Pearl sand. Meanwhile, pay attention to the low temperature Pearl sand in the air will condensation and become damp, which will affect the cooling performance of the next filling.
