CN112299866A

CN112299866A - Method for preparing industrial high-temperature flue gas filtering pipeline by using ceramic matrix composite material

Info

Publication number: CN112299866A
Application number: CN202011132374.0A
Authority: CN
Inventors: 陈庆; 许海鹏; 司文彬; 李钧
Original assignee: Chengdu New Keli Chemical Science Co Ltd
Current assignee: Chengdu New Keli Chemical Science Co Ltd
Priority date: 2020-10-21
Filing date: 2020-10-21
Publication date: 2021-02-02

Abstract

The invention provides a method for preparing an industrial high-temperature flue gas filter pipeline from a ceramic matrix composite, which is characterized in that alumina powder, glass fiber, a pore-forming agent and carboxymethyl cellulose are mixed and stirred into a dry material, then water is added to form a wet material, then the wet material is repeatedly extruded to form a mud material and subjected to aging treatment, then a ceramic green blank pipe is obtained by extrusion, an inorganic film is coated on the periphery of the pipe wall and dried, and finally the industrial high-temperature flue gas filter pipeline is prepared by high-temperature firing and cooling through a kiln. The method provided by the invention can be used for preparing the large-pipe-diameter industrial high-temperature flue gas filtering pipeline, the obtained ceramic pipe has the advantages of low filtering resistance, high efficiency, good high-temperature resistance, good folding resistance, lasting use and convenience in installation, and the ceramic pipe can be reused after being used for a period of time and subjected to back flushing and ash removal, so that the ceramic pipe is convenient to popularize and apply.

Description

Method for preparing industrial high-temperature flue gas filtering pipeline by using ceramic matrix composite material

Technical Field

The invention relates to the technical field of waste gas treatment, in particular to a method for preparing an industrial high-temperature flue gas filtering pipeline by using a ceramic matrix composite material.

Background

With the rapid development of global economy, the energy consumption of industries such as electric power, building materials, metallurgy, steel, chemical engineering and the like is increasing day by day, and meanwhile, the generated waste gas not only has high temperature, but also contains a large amount of dust and harmful gas, and becomes one of important factors of environmental pollution. In recent years, the problem of air environmental quality has been receiving wide attention from all social circles, and therefore, research on treatment processes and materials for filtering and removing dust from high-temperature flue gas is a hot topic at present.

In the high-temperature flue gas dust removal technology, the mature applications are as follows: fiber filtration, electrostatic dust collection, bag dust collection and the like, but the technologies have some problems in the application process. For example, the cloth bag type dust collector can not bear the high temperature of the waste gas, and the electrostatic dust collection has the problems of high one-time investment, large occupied area, insulation and the like. Therefore, the purification technology of smoke dust under high temperature condition belongs to a high and new technology which has higher difficulty and needs to be developed urgently at home and abroad in chemical engineering.

In recent years, various high-performance materials such as fibers are actively researched and developed by various countries to meet the requirement of high-temperature flue gas dust removal, and various novel filter materials are developed vigorously. The high-temperature filtering and dust removing technology is one of the most promising technologies in the aspect of particulate matter trapping in recent years, a filter medium is the core of the high-temperature filtering technology, and the quality of the filter medium directly influences the filtering effect and the service life. Among these, the advent of porous ceramic fibers has provided a possibility for the research and development of this technology, as a CVI-SiC composite filter tube by 3M company consists of a 3-layer structure of an outer filter layer, an intermediate fiber layer, and a fiber inner layer constituting a filter support base. Based on this, many experts and scholars try to produce ceramic tubes by studying the structural performance of the ceramic tubes, however, the existing ceramic tubes generally have the defect of poor filtering effect, and therefore, the research on the novel high-temperature flue gas ceramic filtering tubes is in general focus.

Chinese patent application No. 201911124624.3 discloses a multi-level porous silicon carbide porous ceramic for filtering high-temperature flue gas and a preparation method thereof. The technical scheme is as follows: taking 60-70wt% of silicon carbide, 8-15wt% of alumina powder, 10-15wt% of carbon source and 10-15wt% of simple substance silicon as raw materials, adding 12-18wt% of aluminum sol, 0.1-0.6wt% of polycarboxylate and 20-30wt% of water, and stirring to obtain silicon carbide slurry; soaking polyurethane sponges with two pore diameters into the silicon carbide slurry, taking out the polyurethane sponges, then carrying out extrusion molding by using double rollers to obtain two porous ceramic biscuits with the same plane size, superposing the porous ceramic biscuits orderly from top to bottom, drying the porous ceramic biscuits, sequentially heating the porous ceramic biscuits to the temperature of 200-plus-one (250 ℃), the temperature of 600-plus-one (700 ℃) and the temperature of 1200-plus-one (1400 ℃) at three different rates in a carbon-buried atmosphere or a nitrogen atmosphere, and cooling the porous ceramic biscuits along with a furnace to obtain the multi-level pore silicon carbide porous ceramic. The Chinese patent application No. 201410698988.3 discloses a method for preparing an asymmetric microporous ceramic filter tube membrane by thermal spraying; the invention achieves the effects of solving the dust emission and reducing PM2.5 pollution after the high-temperature flue gas in the metallurgical industry is treated by the asymmetric microporous ceramic filter tube membrane prepared by thermal spraying; the asymmetric microporous ceramic filter tube adopts a three-layer structure, the inner layer is a microporous ceramic membrane filter tube substrate prepared by an isostatic pressing process, the average pore size is larger, the strength of the filter tube is ensured, the middle layer is a ceramic fiber layer which is a transition connection layer and ensures good connection between a support substrate and a surface membrane, the outer layer adopts a thermal spraying coating membrane to obtain a separation membrane with smaller average particle size, and the pore size of the surface of the ceramic tube can reach 0.5-2.5 mu m so as to realize the surface filtration of solid particles.

In order to effectively improve the filtering effect of the ceramic tube on the high-temperature flue gas and promote the development and application of a high-temperature flue gas dedusting material, a novel ceramic composite material filtering tube is necessary to be provided, and then the purpose of efficiently and durably filtering the high-temperature flue gas is achieved.

Disclosure of Invention

Aiming at the defects that cloth bag dust removal cannot resist high-temperature smoke and large tubular products are difficult to prepare in the conventional high-temperature smoke dust removal material, and the problems that a ceramic tube with a single material component is low in dust removal efficiency, large in filtering resistance and poor in fine particle filtering efficiency, the invention provides the method for preparing the industrial high-temperature smoke filter pipeline by using the ceramic matrix composite material, so that the filtering efficiency of the high-temperature smoke filter pipeline is improved, and the high-temperature smoke filter pipeline is good in high-temperature resistance, folding resistance and long in service life.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for preparing an industrial high-temperature flue gas filter pipeline from a ceramic matrix composite material comprises the steps of mixing and stirring alumina powder, glass fiber, a pore-forming agent and carboxymethyl cellulose into a dry material, adding water to form a wet material, repeatedly extruding to form a mud-shaped material, carrying out aging treatment, extruding again to obtain a ceramic green blank pipe, coating an inorganic film on the periphery of the pipe wall, drying, and finally carrying out high-temperature firing and cooling through a kiln to obtain the industrial high-temperature flue gas filter pipeline. The preparation method comprises the following steps:

(1) mixing alumina powder, glass fiber, a pore-forming agent and carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water into the dry materials in the stirrer, and uniformly mixing the water and the dry materials to obtain sticky wet materials;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, and sealing and storing the mud-shaped material to obtain a stale material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying to obtain a ceramic green body pipe;

(5) uniformly coating a film on the periphery of the pipe wall of the ceramic green body pipe, and then drying to obtain the film-coated ceramic green body pipe;

(6) and adding the coated ceramic green body pipe into a kiln for high-temperature sintering, and then cooling to obtain the industrial high-temperature flue gas filtering pipeline, thereby realizing the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material.

Preferably, the glass fiber in the step (1) is one or a combination of more than two of long glass fiber, short glass fiber and alkali-free glass fiber.

Preferably, the pore-forming agent in step (1) is one or a combination of two or more of activated carbon and yellow bamboo powder.

More preferably, the pore-forming agent is a mixture obtained by mixing activated carbon and yellow bamboo powder according to a mass ratio of 1: 1-5.

Preferably, in the preparation of the dry material in the step (1), the mass ratio of the alumina powder, the glass fiber, the pore-forming agent and the CMC is 60:10-30:10-20: 3.

Preferably, in the step (2), the mass ratio of the dry material to the water in the preparation of the wet material is 100: 30-40.

Preferably, the sealed preservation in the step (3) is aging at room temperature for 24-28 h.

Preferably, the drying temperature in the step (4) is 90-100 ℃ and the drying time is 24-28 h.

Preferably, the membrane in step (5) is an inorganic membrane.

More preferably, the inorganic film has one or a combination of two or more of alumina, silica and kaolinite as a main component.

Preferably, the drying temperature in the step (5) is room temperature, and the drying time is 36-40 h.

Preferably, in the high-temperature sintering process in the step (6), the temperature-raising rate at 0-300 ℃ is 5-6 ℃/min, the temperature-raising rate at 300-500 ℃ is 3-4 ℃/min, the temperature-raising rate at 500-800 ℃ is 2-3 ℃/min, the temperature is kept at 800 ℃ for 2-3h, the temperature-raising rate at 800-1100 ℃ is 2-3 ℃/min, and finally the furnace door is opened to naturally cool to room temperature when the temperature is reduced to 200 ℃.

It is known that the particularity of high-temperature flue gas is that the viscosity of the flue gas is greatly changed under high-temperature conditions, the humidity is greatly reduced, and the fine particle agglomeration phenomenon is greatly reduced, so that the separation of fine particles is difficult. In the prior common high-temperature flue gas dust removal technology, cloth bag dust removal can not bear the high temperature of waste gas, wet dust removal can not integrate and utilize the heat energy, and electrostatic dust removal has the problems of high one-time investment, large occupied area, high insulation requirement and the like. The invention creatively utilizes alumina powder, glass fiber, pore-forming agent and carboxymethyl cellulose as raw materials to extrude into ceramic green tube, and further utilizes coating and high-temperature sintering to prepare the ceramic matrix composite high-temperature flue gas filter tube with good filtering performance and durability.

The method comprises the steps of firstly, selecting alumina powder, glass fiber, pore-forming agent and carboxymethyl cellulose as raw materials, and preparing the pipe extrusion material by adding water. Wherein, the alumina ceramic has better conductivity, mechanical strength and high temperature resistance, and is a good raw material for preparing the ceramic tube; the glass fiber is an inorganic non-metallic material with excellent performance, has various types, has the advantages of good insulativity, strong heat resistance, good corrosion resistance and high mechanical strength, can effectively enhance the heat resistance and the folding resistance of the ceramic tube, and prolongs the service life; the pore-forming agent is one or the combination of yellow bamboo powder and active carbon, so that the cost is low and the pore-forming effect is good; the carboxymethyl cellulose is used as a binder, and the aqueous solution of the carboxymethyl cellulose has thickening, film forming and bonding effects. By mixing the dry materials and adding water, when the tubular product is produced in the process, the adding proportion of the dry mixed water and the wet mixed water is 30-40% of the total weight of the mixture, so that the carboxymethyl cellulose in the materials plays a role, and the dry materials can be completely bonded to form a wet material with viscosity.

Further, the wet material with viscosity is added into a small-sized extruder for repeated extrusion, the obtained material has certain strength and certain viscosity, the extrusion material in the extruder can be guaranteed to be pug, the pug is sealed and stored at room temperature, the ageing time is controlled, the pipe extrusion raw material with excellent performance is obtained, and the raw material is put into large-sized pipe extrusion equipment for extrusion and drying, so that the ceramic green body pipe is obtained.

Furthermore, a layer of inorganic film is uniformly coated on the periphery of the tube wall of the ceramic green body tube, then the coated ceramic green body tube is added into a kiln for high-temperature generation, the heating rate of the kiln is adjusted, and preferably two pore-forming agents, namely the yellow bamboo powder and the activated carbon, are mixed according to the mass ratio of 1:1-5, so that the activated carbon and the yellow bamboo powder are burnt to form gas volatilization at the early stage of high-temperature sintering, no additional product is generated, and micro holes are formed in the original structure in the middle of the ceramic support body to play a role in filtering flue gas. After high-temperature sintering and cooling, the high-temperature flue gas filtering pipeline with high-efficiency and durable filtering performance is obtained.

The high-temperature flue gas filtering ceramic tube has a four-layer structure, namely a supporting layer, a middle macroporous filtering layer and an outer micro-filtering layer (divided into an interface layer and a membrane layer), and the thermal expansion performance of structural materials between layers is similar, so that the overhigh size shrinkage rate of a sintered product is avoided; in addition, the melting point temperature of the adhesive of the film structure is lower than the melting points of the adhesive of the intermediate layer and the support body, so that the support body is prevented from collapsing and the like during firing. When the obtained ceramic tube is used for filtering and dedusting flue gas, most dust is intercepted because the surface is a film layer with smaller pore diameter; the particle diameter through the rete is very little, and the aperture of intermediate level and supporter is great and mostly for the straight hole, and the particulate matter can be along with gaseous through this two-layer structure direct discharge to the atmosphere, is difficult for causing the condition of blockking up filtering material. In addition, when back-blowing ash removal is carried out, compressed air firstly passes through the supporting body with larger pore diameter and the intermediate layer, the energy loss is small, a better ash removal effect can be achieved, the recovery rate of flux and filtering precision is high, and the pipe can resist the high temperature of 1100 ℃, has high folding strength and has good use durability.

The prior cloth bag dust removal has the problems of no high temperature flue gas resistance, difficult preparation of large tubular products, low dust removal efficiency of ceramic tubes with single material components, large filtration resistance and poor filtration efficiency on fine particles, and limits the application of the ceramic tubes. In view of the above, the invention provides a method for preparing an industrial high-temperature flue gas filtering pipeline by using a ceramic matrix composite, which comprises the steps of mixing alumina powder, glass fiber, a pore-forming agent and carboxymethyl cellulose, and then putting the mixture into a stirrer to be uniformly stirred into a dry material; adding water into the stirrer, and wet-mixing the dry materials to form a wet material with viscosity; repeatedly extruding the wet material for 3 times by using a small extruder to obtain a muddy material, sealing and storing the muddy material, and ageing the muddy material at room temperature; putting the aged material into large-scale pipe extrusion equipment for extrusion, demolding and drying to obtain a ceramic green blank pipe; uniformly coating a layer of film on the periphery of the pipe wall of the ceramic green body pipe, and naturally drying at room temperature; and (3) firing and cooling the coated ceramic green tube at high temperature by a kiln to obtain the high-temperature flue gas filtering pipeline. The method provided by the invention can be used for preparing the large-pipe-diameter industrial high-temperature flue gas filtering pipeline, the obtained ceramic pipe has the advantages of low filtering resistance, high efficiency, good high-temperature resistance, good folding resistance, lasting use and convenience in installation, and the ceramic pipe can be reused after being subjected to back flushing and ash removal after being used for a period of time, so that the ceramic pipe is convenient to popularize and apply.

The invention provides a method for preparing an industrial high-temperature flue gas filtering pipeline by using a ceramic matrix composite, which has the outstanding characteristics and excellent effects compared with the prior art:

1. compared with the traditional cloth bag dust removal, the industrial high-temperature flue gas filtering pipeline prepared from the ceramic matrix composite material has the advantages of low filtering resistance, high efficiency, high temperature resistance, good folding resistance, lasting use and convenience in installation, and can be recycled after being subjected to back flushing and ash removal after being used for a period of time.

2. In the preparation method, the pore-forming agent forms gas volatilization at the early stage of high-temperature sintering, no additional product is generated, and tiny holes are formed in the original structure in the middle of the ceramic support body to play a role in filtering flue gas. Meanwhile, in the process of producing the tubular product, the obtained wet material has certain strength and certain viscosity, the extrusion material in the extruder is guaranteed to be mud, green bodies are obtained through the determination of ageing time and the extrusion and film coating process of the tubular mold, and finally the large-scale pipe with high temperature resistance of 1100 ℃ and good folding resistance is prepared through high-temperature firing by controlling the heating rate, and the large-scale pipe is high in porosity and good in filtering effect.

Drawings

FIG. 1: the structure of the high-temperature flue gas filtering ceramic pipe product prepared by the method is shown schematically. Wherein: 1-outer film layer, 2-inner layer.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, but it should not be construed that the scope of the present invention is limited to the following examples. Various substitutions and alterations can be made by those skilled in the art and by conventional means without departing from the spirit of the method of the invention described above.

Example 1

(1) Mixing 60kg of alumina powder, 20kg of long glass fiber, 15kg of yellow bamboo powder and activated carbon according to a mass ratio of 1:3 to obtain a mixed pore-forming agent and 3kg of carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water accounting for 35% of the dry material by mass into the stirrer, and uniformly wet-mixing to obtain a wet material with viscosity;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, sealing and storing the mud-shaped material, and ageing for 26 hours at room temperature to obtain an aged material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying at the temperature of 95 ℃ for 26 hours to obtain a ceramic green blank pipe;

(5) uniformly coating a layer of alumina inorganic film on the periphery of the tube wall of the ceramic green body tube, and then drying for 38h at room temperature to obtain the coated ceramic green body tube;

(6) and adding the coated ceramic green body pipe into a kiln to be sintered at high temperature, wherein the heating rate at 0-300 ℃ is 5 ℃/min, the heating rate at 300-500 ℃ is 3 ℃/min, the heating rate at 500-800 ℃ is 2 ℃/min, the temperature is kept for 2h at 800 ℃, the heating rate at 800-1100 ℃ is 2 ℃/min, and finally, opening a furnace door to naturally cool to room temperature when the temperature is reduced to 200 ℃, so that the industrial high-temperature flue gas filtering pipeline can be obtained, and the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material is realized. As shown in the attached figure 1, 1 is an outer film layer formed, and 2 is an inner layer.

Example 2

(1) Mixing 60kg of alumina powder, 15kg of chopped glass fiber, 12kg of yellow bamboo powder and activated carbon according to a mass ratio of 1:2 to obtain a mixed pore-forming agent and 3kg of carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water accounting for 32% of the dry material by mass into the stirrer, and uniformly wet-mixing to obtain a wet material with viscosity;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, sealing and storing the mud-shaped material, and ageing for 25 hours at room temperature to obtain an aged material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying at the temperature of 92 ℃ for 24-28h to obtain a ceramic green body pipe;

(5) uniformly coating a layer of silicon oxide inorganic film on the periphery of the tube wall of the ceramic green body tube, and then drying at room temperature for 37h to obtain the coated ceramic green body tube;

(6) and adding the coated ceramic green body pipe into a kiln to be sintered at high temperature, wherein the heating rate at 0-300 ℃ is 5 ℃/min, the heating rate at 300-500 ℃ is 3 ℃/min, the heating rate at 500-800 ℃ is 2 ℃/min, the temperature is kept for 2.5h at 800 ℃, the heating rate at 800-1100 ℃ is 2 ℃/min, and finally, opening a furnace door to naturally cool to room temperature when the temperature is reduced to 200 ℃, so that the industrial high-temperature flue gas filtering pipeline can be obtained, and the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material is realized.

Example 3

(1) Mixing 60kg of alumina powder, 25kg of alkali-free glass fiber, 18kg of yellow bamboo powder and activated carbon according to a mass ratio of 1:4 to obtain a mixed pore-forming agent and 3kg of carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water accounting for 38% of the dry material by mass into the stirrer, and uniformly wet-mixing to obtain a wet material with viscosity;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, sealing and storing the mud-shaped material, and ageing for 27 hours at room temperature to obtain an aged material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying at the temperature of 98 ℃ for 24-28h to obtain a ceramic green body pipe;

(5) uniformly coating a layer of kaolinite inorganic film on the periphery of the pipe wall of the ceramic green body pipe, and drying at room temperature for 39h to obtain the coated ceramic green body pipe;

(6) and adding the coated ceramic green body pipe into a kiln to be sintered at high temperature, wherein the heating rate at 0-300 ℃ is 6 ℃/min, the heating rate at 300-500 ℃ is 4 ℃/min, the heating rate at 500-800 ℃ is 3 ℃/min, the temperature is kept for 2.5h at 800 ℃, the heating rate at 800-1100 ℃ is 3 ℃/min, and finally, opening a furnace door to naturally cool to room temperature when the temperature is reduced to 200 ℃, so that the industrial high-temperature flue gas filtering pipeline can be obtained, and the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material is realized.

Example 4

(1) Mixing 60kg of alumina powder, 10kg of long glass fiber, 10kg of yellow bamboo powder and activated carbon according to a mass ratio of 1:1 to obtain a mixed pore-forming agent and 3kg of carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water accounting for 30% of the dry material by mass into the stirrer, and uniformly wet-mixing to obtain a wet material with viscosity;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, sealing and storing the mud-shaped material, and ageing for 24 hours at room temperature to obtain an aged material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying at the temperature of 90 ℃ for 28 hours to obtain a ceramic green pipe;

(5) uniformly coating a layer of alumina inorganic film on the periphery of the tube wall of the ceramic green body tube, and then drying at room temperature for 36h to obtain the coated ceramic green body tube;

(6) and adding the coated ceramic green body pipe into a kiln to be sintered at high temperature, wherein the heating rate at 0-300 ℃ is 5 ℃/min, the heating rate at 300-500 ℃ is 3 ℃/min, the heating rate at 500-800 ℃ is 2 ℃/min, the temperature is kept for 2h at 800 ℃, the heating rate at 800-1100 ℃ is 2 ℃/min, and finally, opening a furnace door to naturally cool to room temperature when the temperature is reduced to 200 ℃, so that the industrial high-temperature flue gas filtering pipeline can be obtained, and the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material is realized.

Example 5

(1) Mixing 60kg of alumina powder, 30kg of alkali-free glass fiber, 20kg of yellow bamboo powder and activated carbon according to a mass ratio of 1:5 to obtain a mixed pore-forming agent and 3kg of carboxymethyl cellulose, then putting the mixture into a stirrer, and uniformly stirring to obtain a dry material;

(2) adding water with the mass of 40% of that of the dry material into the stirrer, and uniformly wet-mixing to obtain a wet material with viscosity;

(3) adding the wet material with viscosity into a small extruder, repeatedly extruding for 3 times to obtain a mud-shaped material, sealing and storing the mud-shaped material, and ageing for 28 hours at room temperature to obtain an aged material;

(4) putting the aged material into large-scale pipe extrusion equipment for extrusion, then demolding, and drying at the temperature of 100 ℃ for 24 hours to obtain a ceramic green body pipe;

(5) uniformly coating a layer of kaolinite inorganic film on the periphery of the pipe wall of the ceramic green body pipe, and drying at room temperature for 40h to obtain the coated ceramic green body pipe;

(6) and adding the coated ceramic green body pipe into a kiln to be sintered at high temperature, wherein the heating rate at 0-300 ℃ is 6 ℃/min, the heating rate at 300-500 ℃ is 4 ℃/min, the heating rate at 500-800 ℃ is 3 ℃/min, the temperature is preserved for 3h at 800 ℃, the heating rate at 800-1100 ℃ is 3 ℃/min, and finally, opening a furnace door to naturally cool to room temperature when the temperature is reduced to 200 ℃, so that the industrial high-temperature flue gas filtering pipeline can be obtained, and the preparation of the industrial high-temperature flue gas filtering pipeline by the ceramic matrix composite material is realized.

The test method comprises the following steps:

and (3) testing the filtration performance: the porosity of the sample is tested by adopting the Archimedes principle to represent the filtering performance of the sample, and the test result is shown in Table 1;

and (3) durability test: the sample flexural strength is tested by a three-point bending method with reference to GB/T6569-2006, the flexural strength is used for representing the durability of the sample, the span is 30mm, the loading rate is 0.5mm/min, and the flexural strength is R =3 FL/(2 bh)²) (ii) a Wherein R-flexural strength, F-maximum pressure generated at the breaking load, L span, b-sample width, h-sample height.

Table 1:

as can be seen from Table 1, the method can prepare the large-diameter high-temperature flue gas filtering ceramic tube, and has high porosity and low filtering resistance; high breaking strength, high durability and long service life.

Claims

1. The method for preparing the industrial high-temperature flue gas filter pipeline from the ceramic matrix composite is characterized in that the industrial high-temperature flue gas filter pipeline is prepared by mixing and stirring alumina powder, glass fiber, a pore-forming agent and carboxymethyl cellulose into a dry material, then adding water to form a wet material, then repeatedly extruding to form a mud-like material and carrying out aging treatment, then extruding to obtain a ceramic green blank pipe, then coating an inorganic film on the periphery of the pipe wall and drying, and finally sintering at high temperature in a kiln and cooling, wherein the specific preparation method comprises the following steps:

2. The method for preparing the industrial high-temperature flue gas filtering pipe from the ceramic matrix composite according to claim 1, wherein in the step (1), the glass fiber is one or a combination of two or more of long glass fiber, short glass fiber and alkali-free glass fiber.

3. The method for preparing the industrial high-temperature flue gas filtering pipe from the ceramic matrix composite according to claim 1, wherein the pore-forming agent in the step (1) is one or a combination of more than two of activated carbon and yellow bamboo powder.

4. The method for preparing the industrial high-temperature flue gas filter pipeline from the ceramic matrix composite according to claim 1, wherein in the step (1), the mass ratio of the alumina powder, the glass fiber, the pore-forming agent and the CMC is 60:10-30:10-20: 3.

5. The method for preparing the industrial high-temperature flue gas filtering pipe from the ceramic matrix composite material according to claim 1, wherein in the step (2), the mass ratio of dry materials to water in the wet material preparation is 100: 30-40.

6. The method for preparing the industrial high-temperature flue gas filter pipeline from the ceramic matrix composite according to claim 1, wherein the sealing preservation in the step (3) is aging at room temperature for 24-28 h.

7. The method for preparing the industrial high-temperature flue gas filter pipeline from the ceramic matrix composite material according to claim 1, wherein the drying temperature in the step (4) is 90-100 ℃ and the drying time is 24-28 h.

8. The method for preparing the industrial high-temperature flue gas filtering pipeline from the ceramic matrix composite according to claim 1, wherein the membrane in the step (5) is an inorganic membrane, and the main component of the inorganic membrane is one or a combination of more than two of alumina, silica and kaolinite.

9. The method for preparing the industrial high-temperature flue gas filter pipeline from the ceramic matrix composite according to claim 1, wherein the drying temperature in the step (5) is room temperature, and the drying time is 36-40 h.

10. The method for preparing the industrial high-temperature flue gas filtering pipe from the ceramic matrix composite material as claimed in claim 1, wherein in the high-temperature sintering process in the step (6), the temperature rise rate at 0-300 ℃ is 5-6 ℃/min, the temperature rise rate at 300-.