Corrosion is one of the most common causes of bag filter damage. Because the flue gas contains a variety of corrosive substances, the corrosive effect is greater in high temperature environment, and the filter bag will be damaged. Dust removal bag can be said to be the heart of vacuum cleaner, and the selection of dust removal bag is very important. Dust removal bag directly affects the dust removal efficiency of vacuum cleaner, and the design and filter materials of dust removal bag should pursue efficient dust removal effect.

Corrosion of dust bag is often caused by three gases. Filter bag manufacturers have summarized that the following three gases can cause corrosion of dust removal bags.

①strong oxidant

For example, when the styrene dust bag works at 160℃, when the oxygen content exceeds the standard (> 12%), a large amount of oxygen can attack the S bond in polystyrene molecules and combine with it. As a result of the reaction, polystyrene fibers become dark and brittle, and their strength decreases.

We will find that the surface color of polypropylene fiber bags exposed to sunlight will turn brown. If it is not treated for a long time, it will easily lead to the decrease of fiber strength, and the dust bag will be damaged due to the decrease of 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. NO2 can be considered too much, but NO2 is a strong oxidant, and most of it can oxidize filter fibers. Oxidants include nitrogen oxides, hydrogen sulfide, ammonia, chlorine, etc. Strengthening process and equipment control can reduce oxidation corrosion.

② acid gas

In the case of using high-temperature filter materials, sulfide is the main material. When there are many acidic gases in high temperature flue gas, it is recommended to use dust removal bags with good acid resistance. Acid gas includes sulfur dioxide, sulfur trioxide, hydrogen sulfide, hydrogen chloride, hydrogen fluoride, etc.

If the ordinary dust bag is used, the acid flue gas will corrode the fiber structure in the dust bag, which will lead to the decrease of the strength of the dust bag and eventually damage. Traces of damage are from outside to inside. Cooling can reduce the corrosion of acid gas to dust bag.

③ alkaline gas

Mainly occurs under the condition of containing ammonia, mainly ammonia. Damage and acid corrosion means that lowering the temperature can reduce the corrosion of alkaline gas to dust bag.