A high temperature resistant dust removal and denitrification integrated fiber filter tube and preparation method thereof

Abstract

The present invention provides a high-temperature resistant dust removal and denitrification integrated fiber filter tube and a preparation method thereof. The preparation method comprises: soaking the fiber in a modifier for modification, followed by washing, first drying, and first calcination to obtain modified fiber; adding the modified fiber and the dispersant into water, stirring to obtain a dispersion, then mixing the binder and water evenly, and adding the mixture into the dispersion to obtain a mixed solution; mixing the catalyst and water evenly in a certain proportion, ultrasonically dispersing to obtain a catalyst slurry; adding the catalyst slurry into the mixed solution and stirring evenly to obtain a mixed slurry; injecting the mixed slurry into a molding mold, molding, and demolding, and then performing a second drying and a second calcination in sequence. The present invention prepares a dust removal and denitrification integrated fiber filter tube suitable for high temperature environment by one-time molding, with a simple process and a high yield, and the obtained fiber filter tube can not only remove dust, but also denitrify flue gas. It has excellent high temperature resistance and acid and alkali corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature flue gas filtration, and in particular relates to a high-temperature resistant dust removal and denitrification integrated fiber filter tube and a preparation method thereof. Background Art

[0002] In the chemical, metallurgical, petroleum, electric power and other industries, a large amount of high-temperature dusty gas is often discharged, which seriously pollutes the atmospheric environment and poses a huge threat to human health. On this basis, it is necessary to remove dust from these high-temperature dusty gases and remove harmful substances to meet environmental emission standards and reduce pollution. Due to the high temperature and strong gas corrosiveness in the purification and dust removal process of high-temperature gas, there are high requirements for the filter materials used. At present, the most commonly used filter materials are microporous ceramics and special metal materials. However, due to the porous characteristics of ceramic fibers, their strength is relatively low, and they are easily damaged and broken during continuous work, shortening their service life. Metal materials are not resistant to high temperatures, so they are not suitable for use in high or even ultra-high temperature (≤1400℃) environments, which restricts the industrial application of high-temperature filters.

[0003] Therefore, developing and researching a new type of high-temperature filter is an urgent issue that needs to be solved in current high-temperature dust removal research.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a high temperature resistant dust removal and denitrification integrated fiber filter tube and a preparation method thereof, so as to solve the above problems.

[0006] In order to achieve the above objectives, the present invention particularly adopts the following technical solutions:

[0007] A method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube comprises the following steps:

[0008] S1: soaking the high-silica fiber in a modifier consisting of a zirconium oxychloride hydrochloric acid solution and / or a titanium tetrachloride solution for modification, followed by washing, first drying, and first calcining to obtain modified fiber;

[0009] Preferably, the temperature of the first calcination is 500-1000°C;

[0010] Preferably, the mass fraction of the modifier is 0.5-2%;

[0011] Further preferably, the modifier comprises zirconium oxychloride hydrochloric acid solution and titanium tetrachloride solution;

[0012] S2: adding the modified fiber and the dispersant into water, stirring to obtain a dispersion, then mixing a binder and water evenly, and adding the mixture into the dispersion to obtain a mixed solution;

[0013] Preferably, the dispersant includes one or more of sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, poly(meth)acrylic acid derivatives and maleic anhydride copolymers;

[0014] Preferably, the binder comprises an organic binder and / or an inorganic binder;

[0015] Further preferably, the binder includes an organic binder and an inorganic binder;

[0016] Optionally, the organic binder includes one or more of polyethylene glycol, polyacrylic acid and polyphenylacrylic acid;

[0017] Optionally, the inorganic binder includes one or more of silica sol, alumina sol, and silica-alumina sol;

[0018] Preferably, the mass ratio of the organic binder, the inorganic binder and water is 1-10:30-80:1-10;

[0019] S3: mixing the catalyst and water in a ratio of 1-2:1, and ultrasonically dispersing to obtain a catalyst slurry;

[0020] Preferably, the catalyst comprises one or more of vanadium-titanium based, molecular sieve based, manganese based and rare earth based catalysts;

[0021] Further, the catalyst comprises vanadium oxalate, ammonium metatungstate and titanium dioxide;

[0022] More preferably, the mass ratio of vanadium oxalate, ammonium metatungstate, titanium dioxide and water is 0.2:0.04:1:2;

[0023] S4: adding the catalyst slurry obtained in S3 with a mass of 10-30% of the mass of the mixed liquid in S2 to the mixed liquid in S2 and stirring evenly to obtain a mixed slurry;

[0024] S5: injecting the mixed slurry described in S4 into a molding mold, molding it, demoulding it, and then sequentially undergoing a second drying at a temperature of 100-200° C. for a time of 2-6 hours and a second calcination at a temperature of 500-600° C. for a time of 2-4 hours to obtain the product.

[0025] The molding comprises: during the injection of the mixed slurry, the molding mold rotates at a speed of 80-150 r / min until the injection is completed, and then the molding mold is evacuated to a vacuum, and the negative pressure state is maintained for 10-20 minutes before slowly releasing the pressure.

[0026] The present invention also provides a high temperature resistant dust removal and denitrification integrated fiber filter tube, which is prepared by the preparation method of the present invention.

[0027] The high-silica fiber used in the present invention has a silicon oxide content of 96-98%, a continuous temperature resistance of 1000 degrees Celsius, and a short-term temperature resistance of 1400 degrees Celsius. It has better temperature resistance than aluminum silicate fiber, high aluminum fiber, zirconium-containing fiber, aluminum oxide fiber, alkali metal fiber, and basalt fiber. In addition, the high-silica fiber maintains good performance stability in organic and inorganic acids (except hydrofluoric acid, phosphoric acid and hydrochloric acid) even at high temperatures, as well as in weak alkalis. The present invention creatively uses high-silica fiber to prepare fiber tubes. Compared with porous ceramics and metal filter materials, high-silica glass fiber materials have low thermal conductivity, good resistance to high thermal shock, are inert to most chemicals, have good corrosion resistance to high-temperature compounds, corrosive substances, and weakly alkaline molten alloys, and can work normally and continuously under high-temperature conditions.

[0028] Beneficial effects of the present invention:

[0029] The present invention adopts a one-time molding method to prepare an integrated fiber filter tube for dust removal and denitrification suitable for high temperature environments, simplifies the structure of the fiber filter tube, and has a simple preparation process, low energy consumption, improved yield, and cost savings.

[0030] The fiber filter tube can not only remove dust, but also denitrify flue gas. It also has excellent high temperature resistance, acid and alkali corrosion resistance, low surface resistance, high dust removal efficiency, and long service life. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0034] S1: firstly, the high-silica fiber is immersed in a zirconium oxychloride hydrochloric acid solution with a mass fraction of 0.5% for modification treatment, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide;

[0035] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0036] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0037] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0038] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0039] Example 2

[0040] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0041] S1: firstly, the high-silica fiber is immersed in a zirconium oxychloride hydrochloric acid solution with a mass fraction of 1% for modification, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide;

[0042] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0043] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0044] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0045] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0046] Example 3

[0047] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0048] S1: firstly, the high-silica fiber is immersed in a zirconium oxychloride hydrochloric acid solution with a mass fraction of 1.5% for modification treatment, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide;

[0049] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0050] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0051] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0052] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0053] Example 4

[0054] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0055] S1: firstly, the high-silica fiber is immersed in a zirconium oxychloride hydrochloric acid solution with a mass fraction of 2% for modification, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide;

[0056] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0057] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0058] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0059] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0060] Example 5

[0061] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0062] S1: firstly, the high-silica fiber is immersed in a titanium tetrachloride solution with a mass fraction of 1% for modification, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing titanium dioxide;

[0063] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0064] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0065] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0066] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0067] Example 6

[0068] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0069] S1: firstly, the high-silica fiber is immersed in a titanium tetrachloride solution with a mass fraction of 2% for modification, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing titanium dioxide;

[0070] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0071] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0072] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0073] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0074] Example 7

[0075] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0076] S1: firstly, the high-silica fiber is immersed in a mixed solution of 1% by mass zirconium oxychloride hydrochloric acid and 1% by mass titanium tetrachloride solution for modification treatment, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide and titanium dioxide;

[0077] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0078] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0079] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0080] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0081] Example 8

[0082] This embodiment provides a method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, which specifically includes the following steps:

[0083] S1: firstly, the high-silica fiber is immersed in a mixed solution of 2% by mass zirconium oxychloride hydrochloric acid and 2% by mass titanium tetrachloride solution for modification treatment, washed, dried, and calcined at 750° C. to obtain a modified high-silica fiber containing zirconium dioxide and titanium dioxide;

[0084] S2: Dispersing and stirring the modified high-silica fiber obtained in S1 in water, adding sodium pyrophosphate and continuing to stir evenly to obtain a modified high-silica fiber dispersion, then mixing polyethylene glycol, silica sol and water in a mass ratio of 10:80:10 and adding them to the modified high-silica fiber dispersion and stirring evenly to obtain a modified high-silica fiber mixed solution;

[0085] S3. The oxalic acid vanadium, ammonium metatungstate, titanium dioxide and water were mixed in a mass ratio of 0.2:0.04:1:2 and dispersed by ultrasound for 2h to obtain a catalyst slurry;

[0086] S4: slowly adding the catalyst slurry obtained in S3 to the modified high-silica fiber mixed solution in S2 and stirring evenly to obtain a mixed slurry;

[0087] S5: Inject the mixed slurry obtained in S4 into the molding mold. During the mixed slurry injection process, the mold is rotated at a speed of 80r / min until the mixed slurry is completely added. Then, the vacuum pump connected to the mold is started to suck until no liquid flows out. The negative pressure state is maintained for 10 minutes and then the pressure is slowly released. Finally, the mold is demolded to obtain a high-silica fiber filter tube semi-finished product. The high-silica fiber filter tube semi-finished product is dried at 200°C for 4h and calcined at 600°C for 4h to obtain the high-temperature resistant dust removal and denitrification integrated fiber filter tube.

[0088] Comparative Example 1

[0089] This comparative example provides a method for preparing a fiber filter tube, which is different from Example 1 in that this comparative example does not include the fiber modification step S1 in Example 1, and directly disperses the high-silica fiber in water to form a mixed liquid with a dispersant, a binder, etc. The process parameters of other steps are the same as those of Example 1.

[0090] Comparative Example 2

[0091] This comparative example provides a method for preparing a fiber filter tube, which is different from Example 1 in that this comparative example does not include S3 and S4 in Example 1, that is, does not include the step of adding a catalyst, and directly injects the mixed liquid formed by dispersing high silica fiber in water and a dispersant, a binder, etc. into a molding mold. The process parameters of other steps are the same as those of Example 1.

[0092] The fiber filter tubes prepared in Examples 1-8 and Comparative Examples 1-2 were subjected to performance tests, and their acid resistance, alkali resistance and denitrification function were tested respectively. The results are shown in Table 1 below:

[0093] Table 1 Performance test results of fiber filter tubes prepared in Examples and Comparative Examples

[0094]

[0095]

[0096] It can be seen from Table 1 that the high-temperature resistant dust removal and denitrification integrated fiber filter tube provided by the present invention has excellent dust removal and denitrification performances and is resistant to acid and alkali corrosion.

[0097] By longitudinally comparing Examples 1-4, 5 and 6, 7 and 8 respectively, the mixed solution of Example 5 with 1% titanium tetrachloride solution added can be used normally in an alkaline environment of pH <8, while the mixed solution of Example 6 with 2% titanium tetrachloride solution added can be used normally in an alkaline environment of pH <10, the mixed solution of Example 7 with 1% zirconium oxychloride hydrochloride and 1% titanium tetrachloride solution added can be used normally in an alkaline environment of pH <9.5, and the mixed solution of Example 8 with 2% zirconium oxychloride hydrochloride and 2% titanium tetrachloride solution added can be used normally in an alkaline environment of pH <12. By comparing Example 1 and Comparative Example 1 horizontally, it can be seen that the alkali resistance of the filter tube is mainly determined by the content of the active ingredient of the modifier contained in the fiber. When zirconium oxychloride hydrochloride solution is used as the modifier, the active ingredient of the modifier contained in the modified fiber is zirconium dioxide. The higher the mass fraction of the zirconium oxychloride hydrochloride solution used, the higher the content of zirconium dioxide, and the better the fiber alkali resistance; when titanium tetrachloride solution is used as the modifier, the active ingredient of the modifier contained in the modified fiber is titanium dioxide. The higher the mass fraction of the titanium tetrachloride solution used, the higher the content of titanium dioxide, and the better the fiber alkali resistance. The same is true when a mixed solution of zirconium oxychloride hydrochloride solution and titanium tetrachloride solution is used, and the synergistic effect of zirconium dioxide and titanium dioxide further enhances the modification effect, which is verified by the test results of Example 1 and Example 7. The high silica fiber used in the present invention can continuously withstand a temperature of 1000°C, a short-term temperature of 1400°C, and can maintain good filtering performance, removing about 99% of PM2.5. Furthermore, by modifying the fiber, a layer of zirconium and titanium mixed film is formed on the fiber surface, which inhibits further erosion by alkali ions, thereby improving the alkali resistance of the fiber. However, the fiber tube made of the unmodified fiber in Comparative Example 1 does not have alkali resistance.

[0098] By comparing Example 1 and Comparative Example 2, it can be seen that if no catalyst is added during the preparation of the fiber tube, the prepared fiber tube does not have denitration performance.

[0099] The fiber filter tube provided by the present invention can evenly distribute the denitration catalyst on the dust removal tube, with a large contact area, which can maximize the residence time and removal efficiency, and can reduce the NO in the flue gas. X Reacts with NH3 to generate N2 and H2O. Compared with conventional dust removal fiber tubes, the dust removal fiber tubes with composite denitrification catalysts have no obvious attenuation of dust removal function under the premise of having denitrification function. The overall dust filtration efficiency is high, and can achieve continuous and stable ultra-low dust emissions (<5mg / Nm 3 concentration level).

[0100] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several variations and improvements can be made, which all belong to the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. A method for preparing a high temperature resistant dust removal and denitrification integrated fiber filter tube, characterized in that: The steps include: S1: soaking the fiber in a modifier for modification, followed by washing, first drying, and first calcining to obtain modified fiber; S2: adding the modified fiber and the dispersant into water, stirring to obtain a dispersion, then mixing a binder and water evenly, and adding the mixture into the dispersion to obtain a mixed solution; S3: uniformly mixing the catalyst and water in a certain proportion, and ultrasonically dispersing to obtain a catalyst slurry; S4: adding the catalyst slurry obtained in S3 to the mixed solution in S2 and stirring evenly to obtain a mixed slurry; S5: injecting the mixed slurry described in S4 into a molding mold, molding it, demoulding it, and then sequentially performing a second drying and a second calcination to obtain the product.

2. The preparation method according to claim 1, characterized in that: The step S1 satisfies one or more of the following conditions: a. The fiber comprises high silica fiber; b. The modifier comprises a zirconium oxychloride hydrochloric acid solution and / or a titanium tetrachloride solution; c. The temperature of the first calcination is 500-1000°C.

3. The preparation method according to claim 2, characterized in that: The mass fraction of the modifier is 0.5-2%; Preferably, the modifier comprises zirconium oxychloride hydrochloric acid solution and titanium tetrachloride solution.

4. The preparation method according to claim 1, characterized in that: The step S2 satisfies one or more of the following conditions: d. The dispersant comprises one or more of sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, poly (meth) acrylic acid derivatives and maleic anhydride copolymers; e. The binder comprises an organic binder and / or an inorganic binder; Preferably, the binder includes an organic binder and an inorganic binder.

5. The preparation method according to claim 4, characterized in that: The step S2 also satisfies one or more of the following conditions: f. The organic binder comprises one or more of polyethylene glycol, polyacrylic acid and polyphenylene acrylic acid; g. The inorganic binder includes one or more of silica sol, alumina sol, and silica-alumina sol; h. The mass ratio of the organic binder, the inorganic binder and water is 1-10:30-80:1-10.

6. The preparation method according to claim 1, characterized in that: The step S3 satisfies one or more of the following conditions: i. The catalyst includes one or more of vanadium-titanium based, molecular sieve based, manganese based and rare earth based catalysts; j. The certain ratio is 1-2:

1.

7. The preparation method according to claim 6, characterized in that: The catalyst comprises vanadium oxalate, ammonium metatungstate and titanium dioxide; Preferably, the mass ratio of vanadium oxalate, ammonium metatungstate, titanium dioxide and water is 0.2:0.04:1:

2.

8. The preparation method according to claim 1, characterized in that: The mass of the catalyst slurry in step S4 is 10-30% of the mass of the mixed solution.

9. The preparation method according to claim 1, characterized in that: The step S5 satisfies one or more of the following conditions: k. The molding comprises: during the injection of the mixed slurry, the molding mold rotates at a speed of 80-150r / min until the injection is completed, and then the molding mold is evacuated to a vacuum, and the negative pressure state is maintained for 10-20 minutes and then the pressure is slowly released; l. The second drying temperature is 100-200 ° C and the time is 2-6h; m. The temperature of the second calcination is 500-600°C and the time is 2-4h.

10. A high temperature resistant dust removal and denitrification integrated fiber filter tube, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

Images