Which gases will cause corrosion of dust filter bags ?

1. Strong oxidant: For example, when the PPS dust filter bag is working at 160℃, when the oxygen content exceeds the standard (>12%), a large amount of oxygen can attack the S bond in the PPS molecule and bind with it. The result of the reaction is: PPS fiber becomes dark and brittle, and its strength decreases. If it is not treated for a long time, it will easily cause the fiber strength to decrease, and cause the dust filter bag to be damaged due to the decrease in strength. The air contains 21% oxygen and 79% nitrogen (volume ratio). When the temperature is not high, nitrogen is very stable, but high temperature will break the molecular chain of nitrogen and react with oxygen to form NO and NO2. NO can not be considered too much, but NO2 is a strong oxidant and can oxidize most fibers used for filtration . Oxidants include nitrogen oxides, hydrogen sulfide, ammonia, and chlorine. Enhancing control on processes and equipment can reduce oxidation corrosion.

2. Sour gas: mostly appear in the working condition of using high temperature filter material, mainly sulfide. If the high-temperature flue gas contains a lot of acid gas, it is recommended to use a dust bag with better acid resistance. If ordinary dust filter bags are used, acidic flue gas will corrode the fiber structure in the dust filter bags, resulting in a decrease in the strength of the dust filter bags and eventually breakage. The damage marks are from the outside to the inside. Lowering the temperature can reduce the corrosion of the dust filter bag by acid gas. Acid gases include sulfur dioxide, sulfur trioxide, hydrogen sulfide, hydrogen chloride, hydrogen fluoride and so on.

3. Alkaline gas: mostly appear in working conditions containing ammonia gas, mainly ammonia gas. For damage and acid corrosion, lowering the temperature can reduce the corrosion of the dust filter bag by alkaline gas.