Causes of corrosion of ptfe dust filter bag

What is the reason for the corrosion of the ptfe dust filter bag?

Corrosion is one of the common causes of dust bag damage in baghouses. Because the flue gas contains more corrosive substances, it has strong corrosiveness in high temperature environment and will not damage the filter bag. The dust filter bag can be said to be the heart of the vacuum cleaner. The choice of dust filter bag is very important. The dust bag directly affects the dust removal efficiency of the vacuum cleaner. The design of the dust bag and the filter bag must pursue the dust removal effect.

Corrosion of dust bags is usually caused by three gases.

(1) Acid gas: mainly occurs when high temperature filter material is used, mainly sulfide. When the high temperature flue gas contains a large amount of acid gas, it is recommended to use acid-resistant dust removal bags. When using a conventional dust filter bag, the acid-containing flue gas will corrode the fiber structure in the dust filter bag, which will reduce the strength of the dust filter bag and damage it. Damage traces are from outside to inside. Lowering the temperature can reduce the corrosion of the dust bag to the acid gas. Acid gases include sulfur dioxide, sulfur trioxide, hydrogen sulfide, hydrogen chloride, and hydrogen fluoride.

(2) Alkaline gas: mainly occurs in the working environment containing ammonia, mainly ammonia. For damage and acid corrosion, lowering the temperature can reduce the corrosion of the dust filter bag by the alkaline gas.

(3) Hydroxidizing agent: When the PPS filter bag is operated at 160 °C and the oxygen content is standard (>12%), a large amount of oxygen is eroded and combined with PPS molecules. The reaction results showed that the PPS fibers became black and brittle, and the strength decreased. The color of the surface of the PPS fiber filter bag turns brown in sunlight. If it is not treated for a long time, the fiber strength is easily reduced, the strength is reduced, and the dust removal filter bag is damaged. Air contains 21% oxidation and 79% nitrogen. Nitrogen is very stable when the temperature is not high, but high temperature will destroy the nitrogen molecular chain and react with oxygen to generate no or NO2. no may be more, but NO2 is a strong oxidant and will oxidize most of the fibers used for filtration. Oxidants include nitrogen oxides, hydrogen sulfide, ammonia, chlorine, and the like. Strengthening process and equipment control can reduce oxidation corrosion.