With the increase of national efforts in atmospheric management, emission concentration requirements are becoming stricter, and some other dust collectors can no longer meet the requirements of the new standard. Only bag filter can achieve this. Filter bag as a key component of the bag filter, its performance directly affects the emission concentration and service life, the development of filter bag, far behind the development of the filter bag itself, the new filter material continues to appear, the following only two The properties and applications of the more prominent P4 fiber and general resistance fiber were discussed.
P84 fiber
It has a high temperature resistance, the use of temperature up to 260 °C, instantaneous up to 280 °C (instantaneous temperature does not exceed 200h per year), almost equal to glass fiber. The P84 fibres have an irregular blade-like cross-section, increasing the surface area of the fibres and increasing the filtration efficiency, which is increased by 15% to 20% over other fibres. Dust does not infiltrate into the filter cloth, reducing the pressure drop. At the same time, the peeling performance is also good. This is very suitable for places such as cement plants, heat incinerators, and calcium carbide plants that need to handle a large amount of dust. In particular, the combination of P84 fiber and glass fiber, the advantages of both materials have been brought into play, the proportion of adding, depending on the working conditions, the product will be a major development, the use of a very wide range, but the filter bag made of P84 fiber Pay attention to the following points:
(1) Desulfurization is best before exhaust gas enters the filter bag
(2) Nitrogen oxide content NOx < 600mg/ Nm3
(3) SOx content < 600mg/ Nm3
(4) Oxygen content O2 < 22%, water content H2O < 35 %
The advantages of the filter bag made of P84 polysulfide that meets the above conditions will be given prominence, and the service life and emission concentration will achieve the desired results.
Polypropylene fiber (PPS)
Its greatest advantages are good chemical resistance, fiber strength 30% higher than other organic fibers, high filtration efficiency, low penetration of dust, low running resistance, temperature resistance up to 180 °C, instantaneous up to 200 °C (instantaneous limit: no more than annually 400h), low prices. The superior chemical properties make the use of anti-fibre in coal-fired boilers, incinerators, fuel oil, coal-fired coal, and other applications with very good results.
General resistance fiber also has its disadvantages, the biggest drawback is easy to oxidize, so the following points should be taken into account when using general resistance fiber:
(1) Oxygen content is less than 14%
(2) Hydroxides less than 600mg/Nm3
(3) The temperature should not exceed 180 °C
(4) Sulfur content less than 2700 mg/Nm3
4 Conclusion
Filter bag as the “heart” of the filter, in order to give full play to its superior performance, must meet its use conditions, the filter bag is best to be used continuously, timely cleaning, the use of temperature is higher than the acid dew point, water dew point 20 °C, the only way In order to achieve the desired results.