A method for modifying bag filter bags using tobermorite

Abstract

This invention belongs to the field of environmental dust removal technology, and particularly relates to a method for modifying baghouse filter bags using tobermorite. The method includes the preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags. Compared with existing technologies, the beneficial effects of this invention are: 1) By modifying the baghouse filter material fibers with tobermorite, the high-temperature resistance and corrosion resistance of the filter bags are improved, increasing their adsorption capacity for carbon dioxide and nitric oxide, thus meeting the performance requirements of baghouse dust collectors. 2) Comparing the modified filter material with the unmodified filter material, the results show that the modified material can increase the CO2 dust removal efficiency by 4 times, and the best NO removal efficiency in flue gas can reach 85%.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection and dust removal technology, and in particular relates to a method for modifying bag filter bags of baghouse dust collectors using tobermorite. Background Technology

[0002] Baghouse dust collectors are mainly used to capture solid particles in dust-laden gas to purify the gas. Currently, common dust collector filter bag materials often have poor temperature resistance and low corrosion resistance, limiting the adsorption capacity of baghouse dust collectors for carbon dioxide (CO2) and nitric oxide (NO).

[0003] Tobermorite, also known as calcium silicate silicate, refers to hydrated calcium silicate with a calcium-to-silica ratio of 5:6; it is a general term for a group of hydrated calcium silicates. Tobermorite, primarily composed of hydrated calcium silicate (5CaO·6SiO2·5H2O), occurs in platy or acicular forms, with an average density of 170-220 kg / m³. 3 It has a Mohs hardness of 2.5, a flexural strength greater than 0.3 MPa, and a heat resistance temperature of 650℃. When tobermorite of the chemical formula 5CaO·6SiO2·9H2O is heated to 55±5℃ in air without carbon dioxide, it transforms into tobermorite of the 5CaO·6SiO2·5H2O type. Above 730℃, the tobermorite crystals transform into wollastonite.

[0004] Chinese invention patent application number 202111585686.1 discloses a tobermorite seed inducing agent and its preparation method, as well as aerated concrete prepared using this inducing agent and its preparation method. The seed inducing agent comprises calcined kaolin, sodium metasilicate nonahydrate, calcium hydroxide, aluminum sulfate, and water. In the preparation process, calcined kaolin, sodium metasilicate nonahydrate, calcium hydroxide, and water are ultrasonically dispersed and mixed, and aluminum sulfate is added to react, thus obtaining the tobermorite seed inducing agent. The aerated concrete prepared using this inducing agent comprises siliceous raw materials, cement, quicklime, gypsum, aluminum powder paste, water, and the tobermorite seed inducing agent. This method improves the compressive strength of autoclaved aerated concrete by forming adsorption and tobermorite crystal nucleation effects in the slurry, but does not mention the adsorption of CO2 and NO gases.

[0005] Tobermorite possesses excellent high-temperature resistance and corrosion resistance, as well as advantages such as large-pore structure and high specific surface area. However, its application in bag filter cloth is still in its infancy, and its adsorption effect on CO2 and NO gases is not yet clear. In the current context of purifying the atmospheric environment and realizing the development of low-carbon and environmentally friendly industries, it is necessary to conduct further research to align with the low-carbon development strategy. Summary of the Invention

[0006] The purpose of this invention is to provide a method for modifying bag filter bags using tobermorite, overcoming the shortcomings of existing technologies. In order to improve the high temperature resistance and corrosion resistance of the filter bags, tobermorite is used to modify the filter media fibers of the bag filter, thereby improving the adsorption efficiency of the filter bags for carbon dioxide and nitric oxide and meeting the performance requirements of bag filters.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for modifying baghouse dust collector filter bags using tobermorite includes the preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags. The specific steps are as follows:

[0009] 1) Preparation of tobermorite gel: Using silica powder or quartz powder as the silicon source and calcium oxide as the calcium source, the silicon source and calcium source are mixed evenly to obtain a mixture. Chitosan and sodium alginate are used as template agents, potassium hydroxide is used as a co-solvent, and anhydrous ethanol and water are used as solvents. The mixture, template agent and co-solvent are added to the solvent, stirred evenly, heated, filtered, and C–S–H gel and solution are obtained through solvothermal synthesis reaction. The solution is reused.

[0010] 2) Preparation of Mn-C–S–H gel: The C–S–H gel from step 1) was added to a manganese sulfate solution with a solid-liquid ratio of 5 g / ml, stirred, and filtered to obtain Mn-C–S–H gel;

[0011] 3) Preparation of modified Mn-C–S–H gel: The Mn-C–S–H gel in step 2) is mixed with sodium lauryl sulfate, lauroyl glutamic acid and acrylonitrile amine, added to polyethylene wax emulsion and mixed, heated, stirred and dried to obtain modified Mn-C–S–H gel.

[0012] 4) Preparation of tobermorite spun fibers: The modified Mn-C–S–H gel in step 3) is mixed with any one or more of polyurethane, polyamide fiber, polyacrylonitrile fiber, and polyphenylene sulfide, and the mixture is kneaded. The kneaded material is then fed to the spinneret of an electrostatic spinning machine, cooled to form gel filaments, and then stretched to obtain Mn-tobermorite spun fibers.

[0013] 5) Preparation of modified tobermorite filter cloth: When the Mn-tobermorite spun fibers in step 4) are heated to a certain degree, they are taken out and opened, combed into a web, stabilized by natural placement, washed with water, and dried in a forced-air drying oven to obtain Mn-tobermorite filter cloth.

[0014] 6) Filter bag preparation: The Mn-tobermorite filter cloth from step 5) is placed between two layers of polytetrafluoroethylene (PTFE) fiber material, with the three layers of mesh interwoven. They are then bonded together by high-temperature hot pressing to form a bag filter bag for the dust collector. The thickness of the PTFE fiber material layer is 0.3–0.4 mm, and the basis weight is 125–150 g / m². 2 The net density is 70-100 g / m². 2 The thickness of the Mn-tobermorite filter cloth is 1.0–2.0 mm, and the basis weight is 300–450 g / m². 2 .

[0015] In step 1), the mass ratio of silica powder or quartz powder to calcium oxide is 1:(0.5-1.2); the mass ratio of silica powder or quartz powder to potassium hydroxide is 1:(0.1-0.5); the mass ratio of silica powder or quartz powder to chitosan to sodium alginate is 1:(0.001-0.01):(0.001-0.01); the volume ratio of anhydrous ethanol to water is (0.5-2):1; the mass ratio of silica powder or quartz powder to (anhydrous ethanol + water) is (0.05-0.3):1. The heating and stirring reaction temperature is 80-170℃, the heating and stirring reaction time is 0.5-8h, and the stirring speed is 30-300r / min.

[0016] In step 2), the mass ratio of manganese sulfate to C–S–H gel is 1:(0.5–1), the mixing and stirring reaction time is 0.5–6 h, and the stirring speed is 30–300 r / min.

[0017] In step 3), the mass ratio of Mn-C–S–H gel: sodium lauryl sulfate: lauroyl glutamic acid: acrylonitrileamine: polyethylene wax emulsion is 100:(0.1~1):(0.1~1):(1~10):(1~5). The reaction temperature is 20~40℃ and the reaction time is 2~3h. Then, the mixture is impregnated at room temperature in equal volumes for 3~6 hours and dried at 60~80℃ for 2~5h.

[0018] In step 4), the modified Mn-C–S–H gel is prepared by mixing any one or more of polyurethane, polyamide fiber, polyacrylonitrile fiber, or polytetrafluoroethylene in a mass ratio of 1:(0.5–10); the mixing speed is 16–18 r / min with a speed ratio range of 1:(1.1–1.2); the mixing time is 2–6 h; the electrospinning machine model is TL-Pro-LG; the spinning speed is 150–170 m / h; the spinning solution temperature is 100–110 °C; the coagulation bath temperature is -10–-20 °C; and the draw ratio is 6–10.

[0019] In step 5), the tobermorite spun fibers are heated to 200-250℃ at a heating rate of 5-10℃ / min; the opening humidification ratio is 0.5%-1.0%, and the relative humidity in the opening and carding zone reaches 75%-80%; TCC card cloth is used for opening, with a cylinder tooth density of 500-600, a work roller tooth density of 250-320, a doffer tooth density of 300-330, a cylinder speed of 600-700 m / min, and a doffer speed of 40 m / min. ~50m / min; the FZS-C2D2 high-speed, high-impurity carding machine is used for carding and web formation. Machine width: 230-280mm, roller diameter φ55-60mm, burr roller working diameter φ160-170mm, draft ratio 100-110, breast cylinder speed 40-50m / min, main cylinder speed 240-260m / min, doffer speed 5-10m / min; the output web density is 70-100g / m². 2 The unevenness rate is 4-6%; the drying temperature is 120-180℃ and the drying time is 12-24h.

[0020] In step 6), the high-temperature hot pressing temperature is 150℃~180℃, the pressure is 1.0~1.5MPa, and the hot pressing time is 15~30 seconds.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1) By modifying the filter media fiber of the bag filter with tobermorite, the high temperature resistance and corrosion resistance of the filter bag are improved, and the adsorption capacity of the filter bag for carbon dioxide (CO2) and nitric oxide (NO) is increased, which meets the performance requirements of the bag filter.

[0023] 2) Comparing the modified filter media with the unmodified filter media, it was found that the modified media can improve the dust removal efficiency of CO2 by 4 times and the best removal efficiency of NO in flue gas can reach 85%. Attached Figure Description

[0024] Figure 1 This is a comparison of the adsorption curves of CO2 for various examples and comparative examples of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of the present invention. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0027] The components of the embodiments of the invention described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0028] Example 1

[0029] A method for modifying baghouse dust collector filter bags using tobermorite includes the preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags. The specific steps are as follows:

[0030] 1) Preparation of tobermorite gel: First, silica powder and calcium oxide are mixed evenly at a mass ratio of 1:0.5 to obtain a mixture. Chitosan and sodium alginate are used as template agents, potassium hydroxide is used as a co-solvent, and anhydrous ethanol and water are used as solvents. The mass ratio of silica powder to potassium hydroxide is 1:0.1, the mass ratio of silica powder to chitosan to sodium alginate is 1:0.001:0.001, the volume ratio of anhydrous ethanol to water is 0.5:1, and the mass ratio of silica powder to (anhydrous ethanol + water) is 0.05:1. The mixture, template agent, and co-solvent are added to the solvent, heated and stirred at 80°C for 0.5 h at a stirring speed of 30 r / min, filtered, and C–S–H gel and a small amount of anhydrous ethanol solution are obtained through solvothermal synthesis reaction. The small amount of anhydrous ethanol solution obtained by thermal synthesis reaction can be reused in the solvent of step one.

[0031] 2) Preparation of Mn-C–S–H gel: The C–S–H gel prepared in step 1 was added to a manganese sulfate solution with a solid-liquid ratio of 5 g / ml, and the mass ratio of manganese sulfate to C–S–H gel was 1:0.5. The mixture was stirred for 0.5 h at a stirring speed of 30 r / min and then filtered to obtain Mn-C–S–H gel.

[0032] 3) Preparation of modified Mn-C–S–H gel: Mn-C–S–H gel was mixed with sodium lauryl sulfate, lauroyl glutamate, and acrylonitrile amine, and added to a polyethylene wax emulsion. The mass ratio of Mn-C–S–H gel:sodium lauryl sulfate:lauroyl glutamate:acrylonitrile amine:polyethylene wax emulsion was 100:0.1:0.1:1:1. The mixture was heated and stirred at 20℃ for 2 hours, then impregnated at room temperature for 3 hours by equal volume, and finally dried at 60℃ for 2 hours to obtain the modified Mn-C–S–H gel.

[0033] 4) Preparation of tobermorite spun fibers: Modified Mn-C–S–H gel and polyurethane were mixed at a mass ratio of 1:0.5 and kneaded for 2 hours at a speed of 16 r / min with a speed ratio range of 1:1.1. The mixture was then fed into the spinneret of an electrospinning machine, with the spinning speed set at 150 m / h and the spinning solution temperature at 100℃. The mixture was cooled at a coagulation bath temperature of -10℃ to form gel precursor fibers, which were then stretched to obtain Mn-tobermorite spun fibers with a draw ratio of 6.

[0034] 5) Preparation of modified tobermorite filter cloth: Tobermorite spun fibers were heated to 200℃ at a heating rate of 5℃ / min and then opened. TCC carding cloth was used for opening, with cylinder tooth density of 500, working roller tooth density of 250, doffer tooth density of 300, cylinder speed of 600m / min, and doffer speed of 40m / min. The opening humidification ratio was 0.5%, and the relative humidity in the opening and carding zone reached 75%. The web was then carded using an FZS-C2D2 high-speed, high-impurity carding machine, with a width of 230, roller diameter of φ55mm, working diameter of the burr roller of φ160mm, draft ratio of 100, chest cylinder speed of 40m / min, main cylinder speed of 240m / min, and doffer speed of 5m / min. The output web density was 70g / m². 2 The unevenness rate was 4%. After natural stabilization, the filter fiber cloth was washed with water and dried in a forced-air drying oven at 120°C for 12 hours to obtain Mn-tobermorite filter cloth.

[0035] 6) Filter bag preparation: Mn-tobermorite filter cloth is placed between two layers of polytetrafluoroethylene (PTFE) fiber material. The three layers of filter cloth have interwoven meshes and are bonded together by high-temperature hot pressing. The hot pressing temperature is 150℃, the pressure is 1.0 MPa, and the hot pressing time is 15 seconds. The thickness of the PTFE fiber material layer can be 0.3 mm, and the basis weight is 125 g / m³. 2 The mesh density is 70 g / m² 2 The thickness of Mn-tobermorite filter cloth can be 1.0 mm, and the basis weight is 300 g / m². 2 .

[0036] Example 2

[0037] A method for modifying baghouse dust collector filter bags using tobermorite includes the preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags. The specific steps are as follows:

[0038] 1) Preparation of tobermorite gel: First, silica powder and calcium oxide are mixed evenly at a mass ratio of 1:0.85 to obtain a mixture. Chitosan and sodium alginate are used as template agents, potassium hydroxide is used as a co-solvent, and anhydrous ethanol and water are used as solvents. The mass ratio of silica powder to potassium hydroxide is 1:0.3, the mass ratio of silica powder to chitosan to sodium alginate is 1:0.005:0.005, the volume ratio of anhydrous ethanol to water is 1.3:1, and the mass ratio of silica powder to (anhydrous ethanol + water) is 0.15:1. The mixture, template agent and co-solvent are added to the solvent, heated and stirred at 120℃ for 4 hours at a stirring speed of 180 r / min, filtered, and C–S–H gel and a small amount of anhydrous ethanol solution are obtained through solvothermal synthesis reaction. The small amount of anhydrous ethanol solution obtained by thermal synthesis reaction can be reused in the solvent of step one.

[0039] 2) Preparation of Mn-C–S–H gel: The C–S–H gel prepared in step 1 was added to a manganese sulfate solution with a solid-liquid ratio of 5 g / ml, and the mass ratio of manganese sulfate to C–S–H gel was 1:0.75. The mixture was stirred for 3 h at a stirring speed of 180 r / min and then filtered to obtain Mn-C–S–H gel.

[0040] 3) Preparation of modified Mn-C–S–H gel: Mn-C–S–H gel was mixed with sodium lauryl sulfate, lauroyl glutamate, and acrylonitrile amine, and added to a polyethylene wax emulsion. The mass ratio of Mn-C–S–H gel:sodium lauryl sulfate:lauroyl glutamate:acrylonitrile amine:polyethylene wax emulsion was 1:0.5:0.5:5:3. The mixture was heated and stirred at 30℃ for 2.5 h, then impregnated at room temperature for 4.5 h by equal volume, and finally dried at 70℃ for 4 h to obtain the modified Mn-C–S–H gel.

[0041] 4) Preparation of tobermorite spun fibers: Modified Mn-C–S–H gel was mixed with polyamide fibers and polyacrylonitrile fibers at a mass ratio of 1:0.4:0.4 and mixed for 4 hours at a speed of 17 r / min with a speed ratio range of 1:1.15. The mixture was then fed into the spinneret of an electrospinning machine, with the spinning speed set at 160 m / h and the spinning solution temperature at 105℃. The mixture was cooled at a coagulation bath temperature of 5℃ to form gel precursor fibers, which were then stretched to obtain Mn-tobermorite spun fibers with a draw ratio of 8.

[0042] 5) Preparation of modified tobermorite filter cloth: Tobermorite spun fibers were heated to 225℃ at a heating rate of 8℃ / min and then opened. TCC carding cloth was used for opening, with cylinder tooth density of 550, working roller tooth density of 290, doffer tooth density of 315, cylinder speed of 650m / min, doffer speed of 45m / min, and opening humidification ratio of 0.75%; the relative humidity in the opening and carding zone reached 78%. The web was then carded using an FZS-C2D2 high-speed, high-impurity carding machine, with settings of 250mm width, roller diameter φ58mm, burr roller working diameter φ165mm, draft ratio of 105, chest cylinder speed of 45m / min, main cylinder speed of 250m / min, and doffer speed of 8m / min. The output web density was 85g / m². 2 The unevenness rate was 5%. After natural stabilization, the filter fiber cloth was washed with water and dried in a forced-air drying oven at 150°C for 18 hours to obtain Mn-tobermorite filter cloth.

[0043] 6) Filter bag preparation: Mn-tobermorite filter cloth is placed between two layers of polytetrafluoroethylene (PTFE) fiber material. The three layers of filter cloth have interwoven meshes and are bonded together by high-temperature hot pressing. The hot pressing temperature is 165℃, the pressure is 1.25MPa, and the hot pressing time is 23 seconds. The thickness of the PTFE fiber material layer can be 0.35mm, and the basis weight is 135g / m³. 2 The mesh density is 85 g / m² 2 The thickness of Mn-tobermorite filter cloth can be 1.5mm, and the basis weight is 380g / m³. 2 .

[0044] Example 3

[0045] A method for modifying baghouse dust collector filter bags using tobermorite includes the preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags. The specific steps are as follows:

[0046] 1) Preparation of tobermorite gel: First, silica powder and calcium oxide are mixed evenly at a mass ratio of 1:1.2 to obtain a mixture. Chitosan and sodium alginate are used as template agents, potassium hydroxide is used as a co-solvent, and anhydrous ethanol and water are used as solvents. The mass ratio of silica powder to potassium hydroxide is 1:0.5, the mass ratio of silica powder to chitosan to sodium alginate is 1:0.01:0.01, the volume ratio of anhydrous ethanol to water is 2:1, and the mass ratio of silica powder to (anhydrous ethanol + water) is 0.3:1. The mixture, template agent and co-solvent are added to the solvent, heated and stirred at 170℃ for 8 hours at a stirring speed of 300 r / min, filtered, and C–S–H gel and a small amount of anhydrous ethanol solution are obtained through solvothermal synthesis reaction. The small amount of anhydrous ethanol solution obtained by thermal synthesis reaction can be reused in the solvent of step one.

[0047] 2) Preparation of Mn-C–S–H gel: The C–S–H gel prepared in step one was added to a manganese sulfate solution with a solid-liquid ratio of 5 g / ml, and the mass ratio of manganese sulfate to C–S–H gel was 1:1. The mixture was stirred for 6 hours at a stirring speed of 300 r / min and then filtered to obtain Mn-C–S–H gel.

[0048] 3) Preparation of modified Mn-C–S–H gel: Mn-C–S–H gel was mixed with sodium lauryl sulfate, lauroyl glutamate, and acrylonitrile amine, and added to a polyethylene wax emulsion. The mass ratio of Mn-C–S–H gel:sodium lauryl sulfate:lauroyl glutamate:acrylonitrile amine:polyethylene wax emulsion was 100:1:1:10:5. The mixture was heated and stirred at 40℃ for 3 hours, then impregnated at room temperature for 6 hours by equal volume, and finally dried at 80℃ for 5 hours to obtain the modified Mn-C–S–H gel.

[0049] 4) Preparation of tobermorite spun fibers: Modified C–S–H gel was mixed with polyurethane, polyamide fiber, polyacrylonitrile fiber, and polyphenylene sulfide at a mass ratio of 1:0.25:0.25:0.25:0.25. The mixture was kneaded for 6 hours at a speed of 18 r / min with a speed ratio range of 1:1.2. The mixture was then fed to the spinneret of an electrospinning machine, with a spinning speed of 170 m / h and a spinning solution temperature of 110℃. The mixture was cooled at a coagulation bath temperature of 20℃ to form gel precursor fibers, which were then stretched to obtain Mn-tobermorite spun fibers with a draw ratio of 10.

[0050] 5) Preparation of modified tobermorite filter cloth: Tobermorite spun fibers were heated to 250℃ at a heating rate of 10℃ / min and then opened. TCC carding cloth was used for opening, with cylinder tooth density of 600, working roller tooth density of 320, doffer tooth density of 330, cylinder speed of 700m / min, doffer speed of 50m / min, and opening humidification ratio of 1%; the relative humidity in the opening and carding zone reached 80%. The web was then carded using an FZS-C2D2 high-speed, high-impurity carding machine, with settings of 280mm width, roller diameter φ60mm, burr roller working diameter φ170mm, draft ratio of 110, chest cylinder speed of 50m / min, main cylinder speed of 260m / min, and doffer speed of 10m / min. The output web density was 100g / m². 2 The unevenness rate was 6%. After natural stabilization, the filter fiber cloth was washed with water and dried in a forced-air drying oven at 180°C for 24 hours to obtain Mn-tobermorite filter cloth.

[0051] 6) Filter bag preparation: Mn-tobermorite filter cloth is placed between two layers of polytetrafluoroethylene (PTFE) fiber material and bonded together by high-temperature hot pressing. The hot pressing temperature is 180℃, the pressure is 1.5MPa, and the hot pressing time is 30 seconds. The thickness of the PTFE fiber material layer can be 0.4mm, and the basis weight is 150g / m³. 2 The mesh density is 100g / m² 2 The thickness of Mn-tobermorite filter cloth can be 1.5mm, and the basis weight is 450g / m³. 2 .

[0052] Unmodified comparison

[0053] A bag filter bag for a baghouse dust collector is made of two pieces of polytetrafluoroethylene (PTFE) fiber material bonded together by high-temperature hot pressing. The hot pressing temperature is 150℃, the pressure is 1.0 MPa, and the hot pressing time is 15 seconds. The thickness of the PTFE fiber material layer can be 0.3 mm, and the basis weight is 125 g / m³. 2 The mesh density is 70 g / m² 2。

[0054] Table 1 shows a comparison of the heat shrinkage rate, dust removal rate, and NO conversion rate of the filter bags in Examples 1-3 and the unmodified comparative examples.

[0055] Table 1

[0056] Heat shrinkage rate (%) Dust removal rate (%) NO conversion rate Unmodified comparison 7.13 96 21 Example 1 2.02 98 79 Example 2 1.67 98 83 Example 3 1.35 98 85

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all embodiments here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for modifying bag filter bags using tobermorite, characterized in that, The preparation of tobermorite gel, Mn-C–S–H gel, modified Mn-C–S–H gel, tobermorite spun fibers, modified tobermorite filter cloth, and filter bags are detailed below: 1) Preparation of tobermorite gel: Using silica powder or quartz powder as the silicon source and calcium oxide as the calcium source, the silicon source and calcium source are mixed evenly to obtain a mixture. Chitosan and sodium alginate are used as template agents, potassium hydroxide is used as a co-solvent, and anhydrous ethanol and water are used as solvents. The mixture, template agent and co-solvent are added to the solvent, stirred evenly, heated, filtered, and C–S–H gel and solution are obtained through solvothermal synthesis reaction. The solution is reused. 2) Preparation of Mn-C–S–H gel: The C–S–H gel from step 1) was added to a manganese sulfate solution with a solid-liquid ratio of 5 g / ml, stirred, and filtered to obtain Mn-C–S–H gel; 3) Preparation of modified Mn-C–S–H gel: The Mn-C–S–H gel in step 2) is mixed with sodium lauryl sulfate, lauroyl glutamic acid and acrylonitrile amine, added to polyethylene wax emulsion and mixed, heated, stirred and dried to obtain modified Mn-C–S–H gel. 4) Preparation of tobermorite spun fibers: The modified Mn-C–S–H gel in step 3) is mixed with any one or more of polyurethane, polyamide fiber, polyacrylonitrile fiber or polyphenylene sulfide, and the mixture is kneaded. The mixture is then fed to the spinneret of an electrostatic spinning machine, cooled to form gel filaments, and then stretched to obtain Mn-tobermorite spun fibers. 5) Preparation of modified tobermorite filter cloth: When the Mn-tobermorite spun fibers in step 4) are heated to a certain degree, they are taken out and opened, combed into a web, stabilized by natural placement, washed with water, and dried in a forced-air drying oven to obtain Mn-tobermorite filter cloth. 6) Filter bag preparation: Place the Mn-tobermorite filter cloth from step 5) between two layers of polytetrafluoroethylene fiber material, with the three layers of mesh interwoven, and bond them together by high temperature hot pressing to make a bag filter bag for dust collector. wherein the thickness of the polytetrafluoroethylene fiber material layer is 0.3 to 0.4 mm and the grammage is 125 to 150 g / m 2 , the mesh density is 70 to 100 g / m 2 , the thickness of the Mn-tobemite filter cloth is 1.0 to 2.0 mm and the grammage is 300 to 450 g / m 2 .

2. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 1), the mass ratio of silica powder or quartz powder to calcium oxide is 1:(0.5-1.2); the mass ratio of silica powder or quartz powder to potassium hydroxide is 1:(0.1-0.5); the mass ratio of silica powder or quartz powder to chitosan to sodium alginate is 1:(0.001-0.01):(0.001-0.01); the volume ratio of anhydrous ethanol to water is (0.5-2):1; the mass ratio of silica powder or quartz powder to (anhydrous ethanol + water) is (0.05-0.3):

1. The heating and stirring reaction temperature is 80-170℃, the heating and stirring reaction time is 0.5-8h, and the stirring speed is 30-300r / min.

3. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 2), the mass ratio of manganese sulfate to C–S–H gel is 1:(0.5–1), the mixing and stirring reaction time is 0.5–6 h, and the stirring speed is 30–300 r / min.

4. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 3), the mass ratio of Mn-C–S–H gel: sodium lauryl sulfate: lauroyl glutamic acid: acrylonitrileamine: polyethylene wax emulsion is 100:(0.1~1):(0.1~1):(1~10):(1~5). The reaction temperature is 20~40℃ and the reaction time is 2~3h. Then, the mixture is impregnated at room temperature in equal volumes for 3~6 hours and dried at 60~80℃ for 2~5h.

5. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 4), the modified Mn-C–S–H gel is prepared by mixing any one or more of polyurethane, polyamide fiber, polyacrylonitrile fiber, or polytetrafluoroethylene in a mass ratio of 1:(0.5–10); the mixing speed is 16–18 r / min with a speed ratio range of 1:(1.1–1.2); the mixing time is 2–6 h; the electrospinning machine model is TL-Pro-LG; the spinning speed is 150–170 m / h; the spinning solution temperature is 100–110 °C; the coagulation bath temperature is -10–-20 °C; and the draw ratio is 6–10.

6. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 5), the tobermorite spun fibers are heated to 200-250℃ at a heating rate of 5-10℃ / min; the opening humidification ratio is 0.5%-1.0%, and the relative humidity in the opening and carding zone reaches 75%-80%; TCC card cloth is used for opening, with a cylinder tooth density of 500-600, a work roller tooth density of 250-320, a doffer tooth density of 300-330, a cylinder speed of 600-700 m / min, and a doffer speed of 40 m / min. ~50m / min; the FZS-C2D2 high-speed, high-impurity carding machine is used for carding and web formation. Machine width: 230-280mm, roller diameter φ55-60mm, burr roller working diameter φ160-170mm, draft ratio 100-110, breast cylinder speed 40-50m / min, main cylinder speed 240-260m / min, doffer speed 5-10m / min; the output web density is 70-100g / m². 2 The unevenness rate is 4-6%; the drying temperature is 120-180℃ and the drying time is 12-24h.

7. The method for modifying bag filters using tobermorite according to claim 1, characterized in that, In step 6), the high-temperature hot pressing temperature is 150℃~180℃, the pressure is 1.0~1.5MPa, and the hot pressing time is 15~30 seconds.

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