What are the functions of explosion-proof doors?

What is the role of the explosion-proof door? Which parts need to be equipped with an explosion-proof door? These two questions are the contents of the China Security Network's small series below.

The spontaneous combustion of coal powder in the milling system will cause an explosion quickly, and the explosion pressure can reach about 245 kPa. The purpose of installing the explosion-proof door is that once the explosion of the milling system occurs, the explosion-proof door is first broken, and the gas is discharged from the explosion-proof door to the atmosphere, so that the system is relieved of pressure, preventing damage to the equipment and ensuring personal safety.

Generally, the explosion-proof door is designed to withstand a pressure of 147 kPa. The explosion-proof film is made of a 0.5 mm thick galvanized iron sheet or a 0.6-1.0 mm thick lead plate, which is engraved with a cross groove having a half thickness. Explosion-proof films can also be made from 3 to 5 mm thick asbestos sheets.

The explosion-proof door shall be installed on the inlet and outlet pipes of the coal mill, the coarse powder separator, the fine powder separator and its inlet and outlet pipes, the coal powder bin, the spiral powder feeder and the front of the powder discharge machine. According to the relevant regulations, the total area of ​​the explosion-proof door (mm2) shall not be less than 4% of the total volume of the milling system (m3).