How to carry out explosion-proof fire protection in thermal spray production

       In oxygen-acetylene flame spraying, the gas oxygen and acetylene used may cause explosion if used improperly. When gaseous oxygen in a compressed state comes into contact with grease and flammable substances, intense combustion and explosion will occur. Therefore, the utensils that come into contact with oxygen during work must not be contaminated with grease. When the acetylene pressure is 0.15MPa and the temperature reaches 500 ℃~600 ℃, it will explode by itself. The content of acetylene (by volume) is in the range of 2.2% to 81% to form a mixed gas, and the content of acetylene (by volume) is in the range of 2.8% to 93%. The mixed gas formed with oxygen will explode immediately in case of fire. Therefore, the acetylene generator that has just been loaded with calcium carbide should first discharge the acetylene gas mixed with air before it can be used. When dismantling the calcium carbide basket, special attention should be paid to avoid open flames, and the backflow of oxygen into the acetylene generator should be strictly prevented.



    After acetylene is in contact with copper or silver for a long time, copper acetylene (Cu2C2) and silver acetylene (Ag2C2) will be formed, and they will explode when subjected to severe vibration or heated to 110% ~ 120%. Therefore, all appliances in contact with acetylene are prohibited from being made of silver or pure copper, and only copper alloys with a copper content of less than 70% are allowed to be made.

    Acetylene and chlorine, hypochlorite and other compounds will burn and explode, so it is forbidden to use carbon tetrachloride to extinguish the acetylene flame. Oxy-acetylene flame spraying, like oxy-acetylene welding, also has the problem of tempering. Moreover, when spraying hollow workpieces, air holes must be opened on the workpiece. Otherwise, when the working spray is heated, the gas in the inner cavity expands, and its pressure is higher than the strength of the workpiece material, which will cause an explosion. Especially when spraying thin-walled hollow parts, more attention should be paid to opening air holes.