Cloth bag dust removal device for desulfurization and denitrification process

Abstract

The invention discloses a cloth bag dust removal device for a desulfurization and denitrification process. The cloth bag dust removal device comprises a dust removal tank and a cloth bag chamber, a plurality of transverse cloth bags are arranged in the cloth bag chamber; a layer of POSS (Polyhedral Oligomeric Silsesquioxane)-based fluorinated ionic liquid hyperbranched polymer film is attached to the surface of the cloth bag; the POSS-based fluorinated ionic liquid hyperbranched polymer membrane is prepared from polyfunctional polyhedral oligomeric silsesquioxane, fluorinated acrylate, polymeric ionic liquid and a bionic dopamine monomer through free radical copolymerization. By adopting the structure that the cloth bag is transversely arranged, the utilization rate of the surface area of the cloth bag is improved, so that the filtering efficiency is improved; and a layer of POSS-based fluorinated ionic liquid hyperbranched polymer film is attached to the surface of the cloth bag, so that the dust removal efficiency can be remarkably improved, the service life of the cloth bag can be remarkably prolonged, and the cloth bag has excellent anti-adhesion and antistatic properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flue gas treatment, in particular to a bag dust removal device for desulfurization and denitrification process. BACKGROUND

[0002] Desulfurization and denitrification is an important technology in the field of environmental protection, aiming to reduce the emission of sulfur dioxide and nitrogen oxides generated during the combustion of fossil fuels such as coal and oil, thereby reducing the pollution of the atmospheric environment. Particulate matter is generated in the desulfurization and denitrification process, in order to avoid environmental pollution caused by particulate matter, dust removal operation is needed. The existing dust removal device mostly adopts bag dust removal, the traditional bag dust removal filters particles through the vertical strip-shaped bag structure, but the existing device still needs to be improved to improve the filtering efficiency.

[0003] The patent with publication number CN221815572U discloses a dust cleaning mechanism for bag dust removal equipment and a bag dust removal system. The gas cylinder is fixed on the bag dust removal equipment through the gas cylinder seat; the piston rod is arranged in the gas cylinder, one end of the piston rod is connected with the connecting plate in the bag dust removal equipment, the other end of the piston rod is connected with one end of the spring cage; the spring cage is connected with the bag in the bag dust removal equipment along the axial direction. Although the device can provide dust cleaning efficiency, the filtering efficiency still needs to be improved.

[0004] In the SCR reactor, unreacted ammonia gas reacts with SO3 generated by the oxidation of SO2 in the flue gas within a certain temperature range (150℃-230℃) to form ammonium bisulfate (ABS). ABS is a liquid or gel-like salt with extremely strong adhesion and hygroscopicity. When the aerosol carrying ABS enters the downstream bag dust collector, it will stick dust particles to the surface of the filter bag fibers like glue, and absorb moisture in the flue gas to form a dense filter cake that is difficult to remove by pulse cleaning. Once this phenomenon occurs, the operating resistance of the dust collector will increase sharply, leading to increased energy consumption of the induced draft fan, and in severe cases, even forcing the filter bag to be replaced. In addition, fine dust (PM2.5) is prone to static accumulation at high flow rates, further enhancing the coulomb attraction between the dust and the filter bag, making it more difficult to clean. In view of this, it is necessary to improve the traditional bag dust removal device. SUMMARY

[0005] To solve the problems of the prior art, the present application aims to provide a bag dust removal device for desulfurization and denitrification process, which adopts a horizontal bag structure to improve the utilization rate of the bag surface area and thus improve the filtering efficiency; and a layer of POSS-based fluorinated ionic liquid hyperbranched polymer film is attached to the surface of the bag, which can significantly improve the dust removal efficiency and the service life of the bag, and has excellent anti-adhesion and anti-static properties.

[0006] To achieve the above-mentioned objectives, the present application adopts the following technical solutions:

[0007] A bag dust removal device for desulfurization and denitrification process, comprising a dust removal tank and a bag chamber;

[0008] The bag chamber is internally provided with a plurality of transversely arranged bags;

[0009] The surface of the bag is attached with a layer of POSS-based fluorinated ionic liquid hyperbranched polymer film;

[0010] The POSS-based fluorinated ionic liquid hyperbranched polymer film is prepared by free radical copolymerization of multifunctional cage polysilsesquioxane, fluorinated acrylate, polymerized ionic liquid and biomimetic dopamine monomer.

[0011] Preferably, the bag chamber is connected to the top of the dust removal tank, and a plurality of fixing grooves for fixing the bags are arranged in the bag chamber, and the side wall is provided with a back blowing pipeline and a gas outlet, and the inside of the bag is provided with a cage for supporting the bag.

[0012] Preferably, the side wall of the dust removal tank is provided with a gas inlet and a dust outlet at the lower end and the bottom respectively, and the inside is provided with a rotating shaft with a spiral structure.

[0013] Preferably, the molar ratio of multifunctional cage polysilsesquioxane, fluorinated acrylate, polymerized ionic liquid and biomimetic dopamine monomer is (0.02-0.1):(0.4-0.6):(0.2-0.4):(0.1-0.2).

[0014] Preferably, the multifunctional cage polysilsesquioxane is octyl acryloxy propyl-POSS, and the cage core size is 1.5-3.0 nm.

[0015] Preferably, the cation of the polymerized ionic liquid is one of imidazole, pyridine or quaternary ammonium salt, and the anion is one of bistrifluoromethylsulfonylimide, hexafluorophosphate or tetrafluoroborate.

[0016] Preferably, the fluorinated acrylate is perfluoroalkyl ethyl acrylate, and the biomimetic dopamine monomer is dopamine methacrylamide.

[0017] Preferably, the preparation method of the polymer in the POSS-based fluorinated ionic liquid hyperbranched polymer film comprises the following specific steps:

[0018] S1. Under an inert atmosphere, the multifunctional cage polysilsesquioxane, perfluoroalkyl ethyl acrylate, polymerized ionic liquid and biomimetic dopamine monomer are dissolved in a fluorine-containing solvent according to the molar ratio to obtain a mixed solution;

[0019] S2. An initiator and a chain transfer agent are added to the mixed solution to perform solution polymerization to obtain a hyperbranched polymer precursor.

[0020] Preferably, the fluorine-containing solvent is one of trifluorotoluene, hexafluoroxylene, perfluorohexane, the mass ratio between the fluorine-containing solvent and the total mass of all raw materials is 5:1-20:1, the initiator is azobisisobutyronitrile or dibenzoyl peroxide, the amount of which is 0.5%-2.0% of the total mass of all raw materials, and the chain transfer agent is dodecyl mercaptan, the amount of which is 0.05%-0.5% of the total mass of all raw materials.

[0021] The application of the cloth bag dust removal device is used for treating high-humidity flue gas containing ammonium bisulfate aerosol.

[0022] Compared with the prior art, the application has the following beneficial effects:

[0023] (1) The cloth bag is horizontally arranged in the application, in the filtering process, the whole cloth bag contacts the gas to be dedusted, the utilization rate of the cloth bag surface area is greatly improved, the cloth bag surface area is uniform, and the filtering efficiency is improved.

[0024] (2) The cloth bag surface of the application is attached with a POSS-based fluorinated ionic liquid hyperbranched polymer film, the rigid nanocage of the multifunctional POSS is used as a crosslinking point and a rough unit, the extremely low surface energy of the long-chain fluorocarbon acrylate is combined, a stable micro-nano composite rough structure is constructed through molecular self-assembly, the cloth bag surface reaches the super-hydrophobic and super-oleophobic state, the strong repulsive effect on the viscous ammonium bisulfate droplets is generated, and the adhesion is reduced; the polymeric ionic liquid is fixed in the polymer network through a covalent bond, an even and stable ion conductive channel is formed, the rapid intrinsic antistatic property is realized, and the agglomeration and falling problems of the traditional conductive filler are avoided; the bionic dopamine monomer is oxidized and crosslinked in the curing stage, the strong covalent anchoring is formed on the surface of the filter bag fiber, and the wear resistance and acid corrosion resistance of the coating are greatly improved, so that the stability of long-term operation is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The figure is a structural schematic diagram of the application;

[0026] Figure 2 The figure is a structural schematic diagram of the cloth bag in the application;

[0027] Figure 3 The figure is a structural schematic diagram of the dust removal tank in the application.

[0028] The drawings include the following reference signs: 1, dust removal tank, 2, cloth bag chamber, 3, dust outlet, 4, gas outlet, 5, rotating shaft, 6, fan blade, 7, shaft sleeve, 8, support frame, 9, object carrier, 10, motor, 11, motor shaft sleeve, 12, belt, 13, fixed groove, 14, cloth bag, 15, gas inlet, 16, cage. DETAILED DESCRIPTION

[0029] In order to clearly illustrate the technical features of the scheme, the scheme will be described below through specific embodiments.

[0030] Referring to Figure 1 , a bag dust removal device for a desulfurization and denitrification process of the application comprises a dust removal tank 1 and a bag chamber 2. The lower ends of the dust removal tank 1 and the bag chamber 2 are conical. The lower end of the bag chamber 2 is connected to the upper end of the dust removal tank 1, which can be connected by welding or bolts. The lower end of the dust removal tank 1 is provided with a gas inlet 15 for the entry of dust removal gas. The sidewall of the bag chamber 2 is provided with a corresponding gas outlet 4.

[0031] A plurality of horizontally arranged bags 14 are arranged in the bag chamber 2. The bag 14 is provided with a cage 16 for supporting the bag 14. The bag 14 and the cage 16 can adopt a bag dust removal structure. Unlike the existing device, the bag 14 of the present device is horizontally arranged. A fixing groove 13 is arranged on the sidewall of the bag chamber 2 for stabilizing the bottom of the bag 14. The fixing groove 13 can be connected by welding. In order to ensure stability, the end of the cage 16 can be fixed by bolts, which is convenient for disassembly and assembly. A back blowing pipe 17 is arranged in the bag chamber 2 for cleaning the dust on the periphery of the bag 14.

[0032] A rotating shaft 5 is arranged in the dust removal tank 1. An axle sleeve 7 is arranged outside the rotating shaft 5. The axle sleeve 7 is rotatably connected to the rotating shaft. A support frame 8 is arranged outside the axle sleeve 7. The specific structure of the support frame 8 is shown in Figure 2 . Three support rods are arranged in each ring of the support frame 8. The support rods form an angle of 15-45° with the horizontal plane. The three support rods in each ring are arranged in a central symmetrical manner, thereby ensuring stable support. A fan blade 6 is arranged outside the rotating shaft 5. The dust removal tank 1 is provided with a dust outlet 3. The rotating shaft 5 is provided with a spiral structure, which facilitates the rotation of the dust outlet 3 when it is opened.

[0033] In order to realize the rotation of the rotating shaft 5, a belt 12 is preferably used for transmission, because the gear transmission is greatly affected by dust. A carrier table 9 is arranged outside the dust removal tank 1. A motor 10 is arranged on the carrier table 9. The dust removal tank 1 and the bag chamber 2 are arranged in a slope structure. A motor shaft sleeve 11 is arranged on the slope structure. The motor 10 is horizontally rotated through a gear combination structure, and then the output shaft of the motor 10 is connected to the rotating shaft 5 through a belt, thereby realizing the rotation of the rotating shaft 5.

[0034] The principle of pre-filtering large particle dust by the dust removal tank 1 is that the large particle dust is deposited by centrifugal force through the rotation of the gas. Unlike the conventional cyclone dust removal equipment, the gas inlet 15 of the present device is arranged at the lower end in order to realize dust removal. The dust removal tank 1 is rotated by the fan blade 6, thereby realizing the rotation of the gas.

[0035] In order to improve the filtering effect of the cloth bag, a POSS-based fluorinated ionic liquid hyperbranched polymer film is attached to the surface of the cloth bag. The POSS-based fluorinated ionic liquid hyperbranched polymer film is prepared by free radical copolymerization of multifunctional cage polysilsesquioxane, fluorine-containing acrylic ester, polymeric ionic liquid and biomimetic dopamine monomer. The molar ratio of multifunctional cage polysilsesquioxane, fluorine-containing acrylic ester, polymeric ionic liquid and biomimetic dopamine monomer is (0.02-0.1):(0.4-0.6):(0.2-0.4):(0.1-0.2). The multifunctional cage polysilsesquioxane is octyl methacryloxypropyl-POSS, and the cage core size is 1.5-3.0 nm. The cation of the polymeric ionic liquid is one of imidazole, pyridine or quaternary ammonium salt, and the anion is one of bis-trifluoromethylsulfonylimide, hexafluorophosphate or tetrafluoroborate. The fluorine-containing acrylic ester is perfluoroalkyl ethyl acrylate; and the biomimetic dopamine monomer is dopamine methacrylamide.

[0036] The present application introduces multifunctional cage polysilsesquioxane, which has a rigid inorganic siloxane core as a nano-crosslinking point, and gives the polymer film surface a permanent nano-roughness. Combined with the low surface energy of the long-chain fluorocarbon group, the film surface reaches a non-wetting state, thereby producing a strong repulsive effect on viscous ABS droplets. By using polymeric ionic liquid, imidazole, pyridine and other cations are covalently bonded with TFSI and other fluorine-containing anions in the polymer network. Through the micro transition of ions between molecular chains, a continuous conductive network is formed, giving the filter bag excellent static dissipation capacity and eliminating static adsorption force. By introducing biomimetic dopamine monomers, the strong adhesion properties of the o-diphenol group to various substrates under oxidation conditions are utilized to solve the problem of easy peeling of fluorosilicon coatings, ensuring the stability of the dust collector during long-term operation. By adjusting the polymerization process through a chain transfer agent, a highly branched three-dimensional spherical molecular structure is formed. This structure has low melt viscosity, high solubility and a large number of terminal functional groups, which is beneficial to film processing and enrichment of surface functional groups.

[0037] The preparation method of the polymer in the POSS-based fluorinated ionic liquid hyperbranched polymer film comprises the following specific steps:

[0038] S1. Under an inert atmosphere, the multifunctional cage polysilsesquioxane, perfluoroalkyl ethyl acrylate, polymeric ionic liquid and biomimetic dopamine monomer are dissolved in a fluorine-containing solvent in a molar ratio to obtain a mixed solution;

[0039] S2. The initiator and chain transfer agent are added to the mixed solution to perform solution polymerization to obtain a hyperbranched polymer precursor.

[0040] The fluorine-containing solvent is one of trifluorotoluene, hexafluoroxylene and perfluorohexane, the mass ratio between the fluorine-containing solvent and the total mass of all raw materials is 5:1-20:1, the initiator is azobisisobutyronitrile or dibenzoyl peroxide, and the dosage is 0.5%-2.0% of the total mass of all raw materials, and the chain transfer agent is dodecyl mercaptan, and the dosage is 0.05%-0.5% of the total mass of all raw materials.

[0041] The polymerization mechanism of the POSS-based fluorinated ionic liquid hyperbranched polymer film is based on free radical copolymerization, and the key feature is to induce the formation of a three-dimensional network structure by using multifunctional monomers. Under heating conditions, the initiator homolytic cleavage generates primary radicals. The primary radicals attack the vinyl double bonds of each monomer, initiating chain polymerization. Among them, the key monomer octyl methacryloyloxypropyl-POSS has a rigid inorganic cage core and eight peripheral methacrylate groups. This makes each POSS molecule a nanoscale multifunctional crosslinking point. When a growing polymer chain is connected to the POSS core through a double bond, the remaining double bonds on the POSS can continue to react with other growing chains. This process leads to a large number of covalent connections between polymer chains through POSS units, thereby forming a hyperbranched structure or a micro-crosslinked network at an early stage of polymerization, rather than a simple linear polymer. To prevent multifunctional POSS from causing premature gelation of the polymerization system, a chain transfer agent is added to the polymerization system, which actively terminates growing chains through chain transfer reactions and regenerates new radicals, thereby controlling the average molecular weight and branching degree of the polymer, ensuring that the final product has good solubility in solvents, facilitating subsequent processing into a film.

[0042] After the above polymer solution is coated on the surface of the cloth bag and preliminarily dried, different segments of different properties spontaneously orient and microphase separate based on thermodynamic driving during the heat treatment process, which is the key to forming a functional surface. The perfluoroalkyl segment in the polymer side chain (from monomer PFDA) and the low surface energy POSS cage have a strong tendency to migrate to the polymer-air interface to reduce the total surface energy of the system, and they are enriched and tightly packed in the surface layer, forming an outer surface with extremely low surface energy. The rigid POSS nanocage that migrates to the surface acts as a hard physical protrusion, forming an intrinsic nanoscale roughness on the film surface. This nanostructure, combined with the micron-scale structure of the fiber itself, forms a micro-nano dual composite rough structure. The segment containing the ionic liquid group is mainly distributed in the interior and subsurface of the film layer due to its ionophilic nature, forming a continuous molecular-level ion conductive channel in the polymer bulk through the dissociation and migration of ion pairs, rather than relying on physically doped conductive fillers. The segment containing the catechol group (from monomer dopamine methacrylamide, DMA) tends to be enriched at the polymer-filter fiber interface during film formation due to its strong adhesion properties, preparing for subsequent firm adhesion.

[0043] In the final baking stage of the cloth bag, the final curing and firm adhesion of the coating can be achieved. The catechol groups in the dopamine side chain enriched at the interface are oxidized to o-benzoquinone under the action of heat and oxygen in the air. The quinone group and its precursor can form multiple hydrogen bonds, coordination bonds or even covalent bonds with various functional groups on the surface of the filter material fiber (such as -NH2, -OH) or with the PTFE surface through strong complexation, thereby realizing the super strong bonding force of the coating and the substrate. The generated quinone group can also undergo Michael addition or Schiff base reaction with the unoxidized catechol groups on the adjacent polymer chain, resulting in further crosslinking between the polymer chains, significantly improving the overall compactness, mechanical strength and chemical corrosion resistance of the coating.

[0044] Example 1

[0045] In this embodiment, a POSS-based fluorinated ionic liquid hyperbranched polymer is first prepared, and the specific process is as follows:

[0046] Under anhydrous and anaerobic operating environment, the reaction kettle is sequentially added with reaction monomers octyl methacryloxypropyl-POSS, perfluoroalkyl ethyl acrylate, 1- vinyl-3-butyl imidazole bis-trifluoromethylsulfonylimide salt ionic liquid and dopamine methacrylamide with a molar ratio of 0.06:0.5:0.3:0.14. The above monomer mixture is dissolved in trifluorotoluene solvent, and the amount of solvent is 10 times the total mass of all raw materials to ensure that the system still has good dispersibility under high solid content, and the magnetic stirring is started to make the monomers fully dissolved to form a homogeneous transparent solution. After the system temperature is stably raised to 75℃, 1.0% of the initiator azobisisobutyronitrile and 0.2% of the chain transfer agent dodecyl mercaptan based on the total mass of the raw materials are slowly added through a constant pressure dropping funnel. The reaction system is continuously stirred at 75℃ for 24 hours, and the change of solution viscosity is closely monitored during the period.

[0047] After the reaction is completed, the obtained light yellow viscous polymer solution is uniformly coated on the surface of the pretreated polyphenylene sulfide (PPS) needle felt cloth bag by immersion and pulling method. The coated cloth bag is first dried at 80℃ in a blowing drying oven for 2 hours to remove the solvent, and then transferred to a high temperature curing oven at 160℃ for heat treatment for 4 hours. Finally, a layer of POSS-based fluorinated ionic liquid hyperbranched polymer film is formed on the surface of the cloth bag.

[0048] Example 2

[0049] The preparation steps of this embodiment are the same as those of Example 1, and the specific difference is:

[0050] The monomers octyl methacryloyloxypropyl-POSS, perfluoroalkyl ethyl acrylate, 1-allyl-3-methylimidazolium hexafluorophosphate ionic liquid and dopamine methacrylamide were added into the reactor in a molar ratio of 0.1:0.4:0.3:0.2. Hexafluoroxylene was selected as the solvent, and the mass of the solvent was 8 times the total mass of the solutes. At a reaction temperature of 80°C, 1.5% of the total mass of the raw materials was added as an initiator, and 0.3% of dodecyl mercaptan was added as a chain transfer agent. The reaction time was 20 hours.

[0051] Example 3

[0052] The preparation steps of this example are the same as those of Example 1, and the specific difference is that:

[0053] The monomers octyl methacryloyloxypropyl-POSS, perfluoroalkyl ethyl acrylate, 1-allyl-3-methylimidazolium hexafluorophosphate ionic liquid and dopamine methacrylamide were added into the reactor in a molar ratio of 0.1:0.4:0.3:0.2. Hexafluoroxylene was selected as the solvent, and the mass of the solvent was 8 times the total mass of the solutes. At a reaction temperature of 80°C, 1.5% of the total mass of the raw materials was added as an initiator, and 0.3% of dodecyl mercaptan was added as a chain transfer agent. The reaction time was 20 hours.

[0054] Comparative Example 1

[0055] This comparative example uses pure PTFE film-coated filter material, which is prepared by a hot-pressing film-coating process, and the specific steps are as follows:

[0056] The same PPS needle felt as in Example 1 was selected as the base cloth, and the surface was not chemically grafted or modified. A commercially available high-air-permeability expanded polytetrafluoroethylene (ePTFE) microporous film was laminated and compounded with the PPS base cloth on a high-temperature hot press through a high-temperature resistant fluororesin adhesive. The hot-pressing temperature was set to 220°C, the pressure was 0.3 MPa, and the running speed was 2 meters / minute, ensuring that the film and the base cloth were tightly combined and the microporous structure of the film was not damaged.

[0057] Comparative Example 2

[0058] The preparation process of this comparative example is consistent with that of Example 1, and the specific difference is that:

[0059] The octyl methacryloyloxypropyl-POSS monomer was removed, and an equal number of functional groups of a common organic crosslinking agent, ethylene glycol dimethacrylate (EGDMA), was introduced into the formula to replace POSS in order to maintain the crosslinking degree of the polymer network so that it does not become a linear polymer and is lost.

[0060] Comparative Example 3

[0061] The preparation process of the present comparative example is consistent with that of Example 1, and the specific difference is that:

[0062] The polymeric ionic liquid monomer with conductive function is replaced by non-conductive ordinary acrylate monomer methyl methacrylate (MMA) to maintain the structural similarity of the polymer main chain.

[0063] Comparative Example 4

[0064] The preparation process of the present comparative example is consistent with that of Example 1, and the specific difference is that:

[0065] Dopamine methacrylamide monomer is removed.

[0066] Performance detection test

[0067] (1) The cloth bags with polymer films attached in Examples 1-3 and Comparative Examples 1-4 were tested for surface wetting performance and antistatic performance, and the results are shown in Table 1. The specific test methods are as follows:

[0068] Surface wetting performance test: A DSA100 optical contact angle measuring instrument was used to measure the static water contact angle (WCA), hexadecane contact angle (OCA, indicating oleophobicity) and water sliding angle (SA) of the surface of each sample at room temperature. Five different points were selected for each sample to take the average value. This index directly reflects the repellency of the filter material to water vapor and oily ABS aerosol.

[0069] Antistatic performance: According to ASTM D257 standard, a Keithley 6517B high resistance meter was used to measure the surface resistivity of the sample in an environment with relative humidity of 30% and temperature of 25°C. At the same time, charge decay test was carried out, and the time required for the surface voltage to decay from 5000V to 500V was recorded.

[0070] Table 1 Surface wetting performance and antistatic performance of cloth bags of each sample

[0071]

[0072] (2) The cloth bags with polymer films attached in Examples 1-3 and Comparative Examples 1-4 were tested for adhesion and peeling strength and stability, and the results are shown in Table 2. The specific test methods are as follows:

[0073] Adhesion and peeling strength test: A custom-made tensile tester was used to vertically peel off the sample of filter material with a pre-adsorbed layer of ABS dust, and measure the pulling force required to peel off the dust layer per unit area from the surface of the filter material.

[0074] Wear resistance stability test: A Martindale wear tester was used to perform 10000 friction cycles on the surface of the coating under a load of 9kPa, and measure the mass loss rate before and after friction to evaluate the firmness of the coating.

[0075] Table 2 Surface wetting and antistatic properties of each sample bag

[0076]

[0077] According to Table 1 and Table 2, the data of Comparative Example 1 and Comparative Example 2 can find that the introduction of POSS makes the water contact angle jump from 124.6° to 163.5°, and the hexadecane contact angle increases from 88.3° to 155.2°. Although Comparative Example 2 contains fluorocarbon chains, the surface energy is low, but due to the lack of nano-rough structure, it can only reach the ordinary hydrophobic level, and it still shows a wetting tendency for low surface tension oily liquid. This shows that relying solely on chemical low surface energy is not enough to resist sticky aerosols, and the micro-nano dual rough structure constructed by POSS must be combined to form a stable air shielding layer to achieve effective repulsion of ABS droplets. In the dynamic filtration test, this difference causes the peeling force of Comparative Example 2 to be about 5 times that of Example 1, and the residual pressure difference is as high as 540 Pa, indicating that the micro-nano structure is crucial to reducing adhesion.

[0078] Comparing the data of Comparative Example 1, Comparative Example 3 and Comparative Example 1, the surface resistivity of Example 1 is reduced to 10 7 Ω / sq order of magnitude, which belongs to the typical electrostatic dissipation material interval, and the charge decay time is only 0.06 seconds, meaning that the static electricity is neutralized instantly. On the contrary, Comparative Examples 1 and 3 are insulators, and the charge is difficult to dissipate. When filtering dust-containing air flow, a strong electrostatic field will form on the surface of the insulating filter material, adsorbing sub-micron dust into the deep layer of the filter material. The data show that although Comparative Example 3 has excellent hydrophobicity, its residual pressure difference is still much higher than that of Example 1, and the dust removal period is shortened by more than half. This fully proves that it is not enough to solve the hydrophobic problem alone, and the electrostatic adsorption force must be eliminated at the same time to prevent fine dust from accumulating in the deep layer of the bag.

[0079] Comparing Example 1 with Comparative Example 4 can find that the contact angles and filtration performance of the two are similar in the initial stage, but in the abrasion resistance test, the mass loss rate of Comparative Example 4 is as high as 14.8%, and large areas of the coating have peeled off. This shows that the fluorosilicon coating lacking chemical anchor points is extremely easy to fail under mechanical friction. Once the coating falls off, the bare PPS base cloth will be directly exposed to ABS corrosion and adhesion. While Example 1 has only a mass loss of 0.65%, proving that the covalent bond network formed by dopamine oxidation cross-linking firmly nails the polymer film to the fiber surface, ensuring the efficient operation of the dust removal device throughout its life cycle.

[0080] The low pressure difference and low dust peeling force exhibited by Example 1 directly verify the rationality of the design of the horizontal cloth bag dust removal device. Since the binding force between the dust and the cloth bag is extremely weak, at the bottom of the horizontally placed cloth bag, the dust can be in block form under the action of gravity and weak pulse back blowing, and directly fall into the spiral conveyor below. If the high adhesion filter material of Comparative Example 1 is used, the dust will be stuck to the surface of the cloth bag, and the horizontal arrangement will cause difficulty in dust removal, resulting in collapse of the cloth bag cage due to dust accumulation. Therefore, the chemical modification technology of the present application is a prerequisite for the stable operation of the horizontal high-efficiency dust removal structure.

[0081] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the above examples do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A bag filter dust collector for desulfurization and denitrification processes, characterized in that, Includes dust collection tank and baghouse; The baghouse is equipped with several horizontally placed bags. The surface of the bag is coated with a layer of POSS-based fluorinated ionic liquid hyperbranched polymer film. The POSS-based fluorinated ionic liquid hyperbranched polymer membrane is prepared by free radical copolymerization of multifunctional cage-type polysilsesquioxane, fluorinated acrylate, polymeric ionic liquid and biomimetic dopamine monomer.

2. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The baghouse is connected to the top of the dust collector. The baghouse is equipped with multiple fixing slots for fixing the bags, and its side wall is equipped with a backflushing pipe and a gas outlet. The bag is equipped with a cage for supporting the bag.

3. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The dust collector has a gas inlet and a dust outlet at the lower end of its side wall and bottom, respectively, and a rotating shaft with a spiral structure is installed inside.

4. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The molar ratio of the multifunctional cage-type polysilsesquioxane, fluorinated acrylate, polymeric ionic liquid and biomimetic dopamine monomer is (0.02-0.1):(0.4-0.6):(0.2-0.4):(0.1-0.2).

5. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The multifunctional cage-type polysilsesquioxane is octamethacryloxypropyl-POSS, and its cage core size is 1.5-3.0 nm.

6. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The cation of the polymeric ionic liquid is one of imidazole, pyridine, or quaternary ammonium salt, and the anion is one of bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, or tetrafluoroborate.

7. The bag filter dust collector for desulfurization and denitrification processes according to claim 1, characterized in that, The fluorinated acrylate is a perfluoroalkyl ethyl acrylate; the biomimetic dopamine monomer is dopamine methylacrylamide.

8. The bag filter dust collector for desulfurization and denitrification processes according to any one of claims 1-7, characterized in that, The preparation method of the polymer in the POSS-based fluorinated ionic liquid hyperbranched polymer membrane includes the following specific steps: S1. Under an inert atmosphere, multifunctional cage-type polysilsesquioxane, perfluoroalkyl ethyl acrylate, polymeric ionic liquid and biomimetic dopamine monomer are dissolved in a fluorinated solvent in a molar ratio to obtain a mixed solution. S2. Initiator and chain transfer agent are added to the mixed solution to carry out solution polymerization and obtain hyperbranched polymer precursor.

9. The bag filter dust collector for desulfurization and denitrification processes according to claim 8, characterized in that, The fluorinated solvent is one of trifluorotoluene, hexafluoroxylene, and perfluorohexane, and the mass ratio of the fluorinated solvent to the total mass of all raw materials is 5:1-20:

1. The initiator is azobisisobutyronitrile or benzoyl peroxide, and its dosage is 0.5%-2.0% of the total mass of all raw materials. The chain transfer agent is dodecyl mercaptan, and its dosage is 0.05%-0.5% of the total mass of all raw materials.

10. The application of the bag filter dust collector according to claim 1, characterized in that, Used for treating high-humidity flue gas containing ammonium bisulfate aerosol.

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