High-efficiency dust filter material is made of high-performance fiber and high-strength scrim as the main raw materials, which are needle-punched, calendered, singed, heat-setting, emulsion impregnated, laminated and other processes to make various types of high-precision, high-temperature, abrasion and corrosion-resistant filter media products required by actual working conditions.  Its function is to efficiently trap dust particles in dusty gases. The products are mainly used in thermal power generation, building materials, iron and steel, waste incineration, chemical industry, glass and other industries, which can comprehensively improve our air pollution prevention and control ability, realize ultra-clean emission, and meet the national major strategic needs in the field of environmental protection.

Polyphenylene sulfide (PPS) fiber filter material is widely used in industrial furnace kiln flue gas bag filter. It needs to bear various loads during service in complex working conditions, and tensile load is the most common. The PPS fiber is combed by the carding machine, and the axial direction of the single fiber is consistent with the axial direction of the fiber web, and the fibers are connected end to end to form a single-layer fiber web. The fiber web is reciprocally laid with the laying trolley (the speed of the laying trolley is ), and it moves forward with the conveying curtain (the speed is ), so that the fiber axis (web axis) and the filter material axis (fiber axis) are cross-laid. direction of web movement) at an angle (fiber orientation angle). After calculation, the orientation angle of the PPS fiber produced by Yuanchen Technology is 5°. It can be seen that the fiber orientation in the filter material is almost the same as that of the filter material in the transverse direction. After acupuncture, the transverse strength must be much greater than the longitudinal direction. Therefore, a plain woven fabric needs to be added between the two layers of fiber webs to provide warp strength. In fact, the PPS fibers are not completely straight and parallel to each other after being combed by the carding machine. After the two layers of fiber webs and the base fabric are entangled by needle punching, with the drafting of the filter material, the single fibers are in the filter material structure. The mid-space state is more complex and difficult to model structurally. According to GB/T 6719 (Technical requirements for bag filter) and GB/T 3923.1 (Determination of tensile strength and elongation at break of textile fabrics Part 1 (strip method)), PPS filter is used for bag filter. material samples for testing. From a macroscopic point of view, the spatial path and entanglement of fibers are ignored, and the filter material is regarded as a whole. Different from ordinary two-dimensional fabrics, the filter material has a tertiary structure of "fiber layer-base fabric layer-fiber layer" in the thickness direction, and the thickness cannot be ignored, so it can be considered as a three-dimensional fabric. Since the structure of the filter material in the x, y, and z directions is different, the filter material is an orthotropic material. The basic elastic parameters of the filter material are shown in the table. 1. Seamless line pattern The peak load of the PPS filter material in the warp direction is about 1100N, and the peak stress is about 10MPa; the peak load of the filter material in the weft direction is about 1300N, and the peak stress is about 13MPa. For warp stretching, the stretching behavior of the filter material is divided into three stages. In the first stage, the base cloth mainly bears the load, and the fibers hardly work; in the second stage, the composite structure composed of the fiber aggregate and the base cloth bears th...

Fluorine-containing polymer refers to a type of polymer in which all or part of the hydrogen atoms connected to C-C bonds in the polymer are replaced by fluorine atoms. Fluoropolymers are complex in structure, various in variety and widely used, and are usually divided into three types: fluororesin, fluororubber and other fluoroproducts.  Fluoropolymers account for 20% of the total fluorine consumption in the fluorochemical industry. Since American scientist Plunkett synthesized polytetrafluoroethylene in 1938, the products that have been industrially produced and marketed so far include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer ( ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinyl fluoride (PVF), more than 10 varieties and more than 100 brands. 1. Polytetrafluoroethylene (PTFE): the largest fluoropolymer in the market  PTFE is polymerized from the monomer tetrafluoroethylene (TFE), and TFE is obtained by thermal cracking of difluoromonochloromethane (R22). At present, the mainstream TFE production process in the world adopts the steam dilution cracking method. Japan's Daikin and British ICI company jointly developed and put into industrial production. The process features high single-pass conversion, few by-products, and high TFE selectivity. The development of this technology in the domestic PTFE industry began in the late 1970s. Under the auspices of the Second Bureau of the Ministry of Chemical Industry, it was successfully put into production in the early 1990s after the Shanghai Synthetic Rubber Research Institute and other factories and colleges jointly tackled key problems. Thousand-ton TFE industrial equipment and promotion nationwide.  PTFE is formed by free radical polymerization of TFE. Its polymerization methods include bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization (dispersion polymerization), and suspension polymerization and dispersion polymerization are mainly used in industry. At present, suspension resins account for 50%-60% of the global production capacity, dispersion resins account for 20%-35%, and the rest are dispersion emulsions.  1) Suspension polymerization method: Suspension polymerization of tetrafluoroethylene is carried out in an aqueous medium with persulfate as an initiator, followed by smashing, grinding, washing and drying to prepare a suspension polymerization resin. Suspension polymerization is relatively mature and is the main method for synthesizing PTFE in industry.  2) Dispersion polymerization method: It is obtained by dispersing and polymerizing tetrafluoroethylene in an aqueous medium, using perfluorocarboxylate as dispersant and fluorocarbon as stabilizer under the initiation of persulfate or its redox system. Dispersion liquid. The dispersion liquid is coagulated, washed and dried to form a dispersed polymer resin, or heated and separated in the prese...

With the increasingly prominent environmental pollution, air quality issues have attracted more and more attention, and the control of industrial flue gas in the non-electrical industry is a tough battle for the current lucid waters and lush mountains. The development of the iron and steel industry supports the backbone of China's modernization, and the iron and steel industry has made important contributions to my country's economic and social development.   Since 2018, the denitration transformation of sintering machine exhaust gas has been carried out on a large scale across the country. After two years of practice, we have found in some sintering machine denitration, heating furnace denitration or pellet denitration that a large area of denitration catalyst will burst at individual sites, accompanied by sintering and deformation (as shown in the figure below).   The clues that can be collected after careful on-site investigation are: ①The CO content in the flue gas is more than 5000ppm; ②The material of Q235 is deformed; ③The rust of the reactor is more serious; The specific surface area of the post-denitrification catalyst is reduced from the original 40-50m2/g to below 20m2/g; ⑥ The flue gas temperature rises rapidly for many times; and so on.  The conclusion of the above phenomenon analysis is that a flash explosion occurred in the denitration reactor, which was caused by the sudden high temperature impact on the denitration catalyst. situation occurs. In response to the current irreversible situation in the iron and steel industry, Yuanchen Technology has developed an explosion-proof denitration catalyst.  Explosion-proof denitration catalyst is a kind of catalyst that can deal with the sudden situation in the operating flue gas, release a large amount of energy, generate high temperature, and release a large amount of gas in a very short period of time, and can resist strong damage. In addition to the need to reduce sintering and agglomeration of active components, the physical structure of the product is the biggest challenge. Generally, a carrier with a large pore structure, or a hard or extremely flexible carrier is selected.  Yuanchen Technology has long been guided by customer needs and driven by innovation. According to the characteristics of CO contained in the flue gas of the steel industry, it has actively deployed CO pollution control, resource utilization, deflagration prevention and other technology development. After two years of investment and development, Yuanchen Science and Technology Research Institute has developed a series of explosion-proof products, which can resist the explosion caused by flammable gas deflagration and other emergencies and prolong the mechanical life of the catalyst. Next, we will introduce three explosion-proof catalysts of Yuanchen Technology in series, so stay tuned!

It is a very difficult problem to deal with the damaged dust filter bag. Because there is a lot of dust on the surface of the waste filter bag, the dust composition is complex. For example, the filter bag used in the waste incineration industry contains toxic, harmful and corrosive substances such as heavy metals and Er on the surface. .Chemical treatment method can also use high temperature cracking method. pyrolysis method Pyrolysis is to use higher temperature to decompose PTFE. This method is difficult to control the types of decomposition products, and also produces many toxic by-products. In the process of recovering useful decomposition products, the requirements for process equipment and parameter settings are relatively high, and the application of this method is generally discouraged. The pyrolysis method has lower requirements for the PTFE recycled material. Whether it is pure PTFE or filled with other materials, it can be recycled by the pyrolysis method. The factors that affect the pyrolysis are generally: temperature, pressure, time, atmosphere, feeding speed, etc. There is no relevant report on pyrolysis recovery in China, and there is no specific process operation. The main reason is that the process is too complicated and the investment is too large. There are many researches in this area abroad, and some of the results have been put into industrial production: CMSimon et al. Fluidized bed pyrolysis is used to decompose PTFE waste to recover TFE, HFP and OFCB. When the process parameters are the fluidized bed temperature of 600°C and the reaction residence time of 3s, the mass fraction of the recovered material is as high as 91%, and the filler in the waste can also be recovered, such as glass fiber, graphite, copper powder, etc.) This system has the largest The characteristic is that it can be operated continuously. The system has been industrialized in Germany, and the processing capacity of waste PTFE is 400t/year.

Fiber is the most basic raw material for non-woven materials. Since non-woven materials are different from traditional textiles, which are formed by the arrangement and combination of yarns, they are fiber aggregates directly composed of fiber raw materials. have a more direct impact. The fiber raw materials used by non-woven technology are very wide. To produce non-woven products with reasonable performance and price ratio, it is necessary to first understand the role of fibers in non-woven materials, master the basic properties of fibers, and determine the basic properties of fibers according to non-woven processing technology and post-processing technology. and equipment to properly select fiber raw materials. Common fiber raw materials are shown in the figure below. The properties of nonwovens are related to many factors, the most important of which are the properties of the fibers. The influence of fibers on the properties of non-woven materials is mainly reflected in two aspects, on the one hand, the material properties directly expressed by fibers through different non-woven structures; on the other hand, the processing adaptability of fibers in non-woven processing. Also affects the final properties of the nonwoven.  1. The effect of fiber appearance on the properties of nonwovens  The apparent properties of fibers mainly include length, linear density, crimp, cross-sectional shape and surface friction properties, etc. Their effects on the properties of non-woven materials are discussed as follows:  1. Fiber length and length distribution  Long fiber length is beneficial to improve the strength of non-woven materials, which is mainly due to the increase of cohesion between fibers, the increase of entanglement points, the enhancement of entanglement effect, and the improvement of the utilization degree of fiber strength. In the production of bonding method, the fiber length is long, which is also manifested as increased bond points, enhanced adhesion, and increased strength of nonwovens.  2. Fiber linear density  The fiber linear density is small, the obtained non-woven material has high bulk density, high strength and soft hand feeling. Under the condition of the same areal density of non-woven materials, the smaller the fiber linear density, the more fibers, and the contact point and contact area between fibers increase, which increases the bonding area between fibers or increases the bonding area between fibers. Slip resistance, thereby increasing the strength of the nonwoven. However, too fine fibers will cause difficulties in opening, carding and web formation. The fiber linear density generally used in non-woven materials is 1.2~33dtex. Generally, crude fibers are mostly used in carpets and pads, and the main consideration is to improve the elasticity of non-woven materials. For some filter materials, fiber blending or gradient distribution with various linear density specifications from fine to coarse i...