The bag filter used in power plant boiler dust removal is required to be synchronized with the overhaul period of boiler equipment, and 30,000 hours has become the basic service period required by thermal power plants. However, for the same coal-fired power station boiler flue gas dust removal, the domestic application conditions are different from those of foreign countries. The main manifestations are: 1. Coal type: foreign use of clean coal and domestic use of raw coal, in terms of calorific value, ash content, S content, etc. There are differences; 2. Technical level: developed countries have a higher degree of equipment automation, and domestic equipment combines manual and automation; 3. Boiler equipment: boiler equipment in developed countries is relatively advanced, and there are still a large number of small and medium-sized equipment in China. The application environment of dust collection bags is "four highs, one large and one low" (the exhaust flue gas temperature is high, the flue gas content of SO2, NOx, and O2 is high; the dust content is large; the renovation project requires low filter material resistance), due to coal-fired boilers The exhausted flue gas conditions are relatively harsh, and the life of the filter material is facing a severe test. Therefore, when the bag filter is used for dust collection bags, the actual situation of domestic boilers should be considered, and the filter material should be selected according to the purpose.

PPS and PPS+P84 dust collection bag PPS needle felt is currently one of the main filter materials used in the pulse cleaning bag filter of coal-fired power plant boilers. It is mainly suitable for flue gas treatment using low-sulfur coal. Select the polyphenylene sulfide (PPS) fiber produced in the United States, Japan and other countries, and manufacture and process filter materials according to the production process of high temperature resistant filter felt. PPS fiber is produced by only a few large chemical companies in the world, and the products of Japanese companies occupy the main market. The registered trademark of TOYOBO is PROCON/Pukang, the registered trademark of TORAY is TORCON/Triton, and the registered trademark of PHILIP is RYTON/Lyton or Leton , Ryden. At present, samples of PPS fiber have been produced in my country, but it is still in the stage of research and development and trial production. The application conditions of PPS needle felt mainly depend on the properties of PPS fibers. The suitable conditions for dust removal of coal-fired power plant boiler flue gas are: flue gas temperature 120-160℃, SO2 content in flue gas <8%, coal ash content <30 %; pre-coating is required before the boiler is started; when the fuel injection point furnace, the boiler tube bursts, and the flue gas is over-temperature, it is not suitable to directly enter the bag filter, and a bypass flue is required; the bag filter is designed to filter wind speed 1.0 About m/min, the resistance of the dust collector is 1300-1500Pa. Under these conditions, the normal operation of the bag filter bag guarantees a service life of 30,000h. In order to prevent the resistance of PPS needled felt from increasing after long-term use, and to increase the temperature resistance, PPS+P84 composite fiber should be used to make needled felt, in which the P84 fiber content is about 20%. The scientific name of P84 is polyimide. Compared with the PPS fiber rod, the cross section of P84 fiber is multi-lobed. Its irregular fiber cross section increases the surface area of the fiber, and the air permeability of the needle felt increases. The temperature resistance can be appropriately improved. P84 fiber is exclusively produced by Austrian LENZING company. P84 fiber should be used with caution under high humidity to prevent hydrolysis. PPS and PPS+P84 needle-punched felts were mainly imported from abroad at the beginning. Now there are many domestic companies that can produce and provide products in large quantities.