Which gases will cause the air filter bags to corrode?

The corrosion of filter bag is often caused by three kinds of gases. We have summarized the following three gases that can cause the corrosion of dust filter bag.

 1. Strong oxidant: For example, when the PPS dust filter bag is working at 160 °C, when the oxygen content exceeds the standard (>12%), a large amount of oxygen can attack the S bond in the PPS molecule and combine with it. The result of the reaction is that the PPS fibers become dark and brittle, and the strength decreases. Sometimes you will find that the surface color of the PPS fiber cloth bag exposed to sunlight will turn brown. If it is not treated for a long time, it is easy to cause the strength of the fiber to decrease, resulting in the damage of the dust bag due to the decrease of strength. Air contains 21% oxygen and 79% nitrogen (volume ratio). Nitrogen is very stable when the temperature is not high, but high temperature will break the nitrogen molecular chain 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, chlorine, etc. Increased control over processes and equipment can reduce oxidation corrosion.

 2. Acid gas: It mostly occurs 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 removal bags are used, the acid-containing flue gas will corrode the fiber structure in the dust removal bags, resulting in a decrease in the strength of the dust removal bags and eventually damage. Damage marks are from outside to inside. Lowering the temperature can reduce the corrosion of the dust bag by the acid gas. Acid gases include sulfur dioxide, sulfur trioxide, hydrogen sulfide, hydrogen chloride, hydrogen fluoride, etc.

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