RU2796591C1 - Solid fiber burner brick and method for its production - Google Patents

Abstract

FIELD: refractory materials.

SUBSTANCE: surface of the brick body is additionally provided with a coating, which can effectively protect the fiber of the brick body from harsh conditions, improve its high temperature resistance, and help prolong the life of the burner brick. Solid-fiber burner brick contains a solid-fiber brick body and a coating applied to its surface, in which the whole-fiber brick body is obtained from a source material containing, wt.%: fiber from alumina crystals 20-30, amorphous ceramic fiber 5-20, filler from fine powder 20-25, inorganic binder 30-40, organic binder 5-15, flocculant 1-5, while the alumina crystal and amorphous ceramic fibers are composed of a combination of fibers of different lengths.

EFFECT: increasing the bulk density of the product, improving the suction filterability of the fibrous blank, and improving the strength of the blank.

10 cl, 1 tbl

Description

[0001] The present application claims the priority of Chinese Patent Application No. 202011246915.2, filed with the State Intellectual Property Office on November 10, 2020, and entitled "SOLID FIBER BURNER BRICK AND METHOD OF PRODUCING THE same", which is incorporated herein by reference.

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0002] This disclosure relates to the field of refractory materials, and in particular relates to all-fiber burner bricks and a process for making the same.

BACKGROUND OF THE INVENTION

[0003] Currently, the ethylene cracker in the petrochemical industry uses bottom, side, and top burners. Most burner bricks used are made from corundum and heavy cast refractory materials. Although the burner bricks of the above two materials have high strength and can withstand strong erosion at the high temperature of the natural gas burner in the ethylene cracking furnace, the heavy cast refractory also has many disadvantages, which can be summarized as follows:

[0004] (1) Bulk density is large. The weight of a set of heavy burner bricks is 270~300kg, which increases the load on the furnace lining, especially for burner bricks in the upper position, it is very difficult to fix them, and pallets, support plates and protective plates are required, which is estimated at 18kg/set.

[0005] (2) Due to its heavy weight, it needs to be installed piecemeal, it is extremely difficult to lift, and installation requires at least 3 people at the same time. The installation space is small and the operation is very difficult.

[0006] (3) It is not resistant to thermal shock. The burner may crack and the high density material may fall and cause injury to people.

[0007] (4) The thermal conductivity is high, resulting in a high temperature in the burner on the outer wall of the furnace.

[0008] To solve the above problems, the industry has proposed the use of a solid brick burner. The solid fiber burner brick has a small bulk density of 70~100kg/set, and is easy to install, only six steel angles are required, which is estimated at 3kg/set, and two people can complete the entire installation. Solid fiber burner brick has low thermal conductivity and good thermal shock resistance. In addition, it is energy-saving and has a long service life. However, the existing solid-fibre burner brick still has the following problems: the strength of the preform required to resist high-temperature furnace gas scouring cannot be achieved, the wet preform has poor suction filterability, short service life, and so on.

SUMMARY OF THE INVENTION

[0009] With this in mind, it is an object of the present invention to provide an all-fiber burner brick and a method for producing the same. The burner brick provided by the present invention can improve strength and high temperature resistance, and is useful for extending service life.

[0010] The present invention provides a solid fiber burner brick comprising a solid fiber brick body and a coating applied to its surface;

[0011] the all-fiber brick body is obtained/made from a starting material containing the following components in wt.%:

alumina crystal fiber 20% ~ 50%;

amorphous ceramic fiber 5% ~ 20%;

fine powder filler 20% ~ 50%;

inorganic binder 30%~50%;

organic binder 5% ~ 15%;

flocculant 1%~5%;

[0012] The alumina crystal fiber is composed of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in the alumina crystal fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%;

[0013] Amorphous ceramic fiber consists of a combination of fibers of different lengths, and the weight fraction of fibers of different lengths in an amorphous ceramic fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%.

[0014] Preferably, the fine powder filler is a fine alumina powder;

[0015] The fine powder filler is composed of particles of various sizes, and the mass fraction of fine powder filler particles of various sizes in the raw material is:

filler with particle size 200~325 mesh 10% ~ 20%;

1000 mesh filler 10% ~ 30%.

[0016] Preferably, the inorganic binder is a silica sol and/or an aluminum sol;

[0017] The organic binder is starch.

[0018] Preferably, the flocculant is a polyaluminum chloride;

[0019] The thickness of the body of solid fiber bricks is 250~550mm;

[0020] The coating thickness is 5~10 mm.

[0021] Preferably, the coating is formed with a paint containing the following components in wt.%:

high temperature resistant inorganic fiber 10% ~ 50%;

reinforcing filler 10% ~ 20%;

high temperature expanding filler 5% ~ 15%;

carcass filler 7% ~ 30%;

nanopowder 3%~10%;

inorganic suspending agent 0%~20%;

inorganic binder 10% ~ 50%;

organic additive 3% ~ 15%; And

water, accounting for 10% ~ 50% of the total mass of all the above components;

[0022] The length of the high temperature resistant inorganic fiber is 0.01~1 mm.

[0023] Preferably in this coating:

[0024] the nanopowder is selected from one or more nanosilica and nanoalumina powders;

[0025] The high temperature resistant inorganic fiber is selected from one or more of high aluminum content fibers, zirconium-containing fibers, and alumina crystal fibers.

[0026] Preferably in this coating:

[0027] the reinforcing filler is selected from one or more powders of acicular microsilica and pyrophyllite;

[0028] the high temperature expandable filler is selected from one or more kyanite and sillimanite powders;

[0029] the frame filler is selected from one or more powders of alumina, mullite, zircon, and corundum.

[0030] Preferably in this coating:

[0031] the inorganic suspending agent is bentonite;

[0032] the inorganic binder is selected from one or more of aluminum sol, aluminum dihydrogen phosphate, and silica sol;

[0033] The organic additive is selected from one or more of an organic binder, an antiseptic, and an antifreeze.

[0034] The present invention also provides a process for producing a solid fiber burner brick as described in the above technical solutions, comprising:

[0035] a) mixing alumina crystal fiber, amorphous ceramic fiber, inorganic binder, fine powder filler, organic binder and water to form a slurry;

[0036] b) mixing the slurry with the flocculant and then performing vacuum filtration and pressing to obtain a wet preform;

[0037] c) drying the wet preform to obtain a dry preform; And

[0038] d) applying paint to the surface of the dry blank and drying to obtain a solid fiber burner brick.

[0039] Preferably in step a) the slurry concentration is 1 ~ 15% by weight; and in step c), pressing is carried out so that the thickness of the workpiece reaches 250~550 mm.

[0040] The present invention provides an all-fiber burner brick that is prepared by mixing alumina crystal fiber and amorphous ceramic fiber, both of which are a combination of fibers of different lengths, and further adding fine powder fillers of different particle sizes and other additives. This makes the internal structure of the product more uniform, increases the bulk density of the product, and also improves the suction filterability of the fibrous preform, and promotes molding and improves the strength of the preform. The surface of the brick body is additionally provided with a coating, which can effectively protect the fiber of the brick body from harsh conditions, improve its high temperature resistance, and help prolong the life of the burner brick.

[0041] The results of the experiment show that the tensile strength at room temperature of the burner brick of the present invention reaches more than 1.1 MPa, the compressive strength at room temperature reaches more than 0.6 MPa, the compressive strength at high temperature reaches more than 0.7 MPa, and the absolute value of linear shrinkage during heating is less than 0.8%.

DETAILED DESCRIPTION

[0042] The present invention provides a solid fiber burner brick comprising a solid fiber brick body and a coating applied to its surface;

[0043] the all-fiber brick body is obtained/made from a starting material containing the following components in wt.%:

alumina crystal fiber 20% ~ 50%;

amorphous ceramic fiber 5% ~ 20%;

fine powder filler 20% ~ 50%;

inorganic binder 30%~50%;

organic binder 5% ~ 15%;

flocculant 1%~5%;

[0044] The alumina crystal fiber is composed of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in the alumina crystal fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%;

[0045] Amorphous ceramic fiber consists of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in an amorphous ceramic fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%.

[0046] In the present disclosure, the sum of the mass fractions of the above components is preferably 100%.

[0047] The present invention blends alumina crystal fiber and amorphous ceramic fiber, which are both a combination of fibers of different lengths, and further adds fine powder fillers of different particle sizes and other additives. This makes the internal structure of the product more uniform, increases the bulk density of the product, and also improves the suction filterability of the fibrous preform, and promotes molding and improves the strength of the preform. The surface of the brick body is additionally provided with a coating, which can effectively protect the fiber of the brick body from harsh conditions, improve its high temperature resistance, and help prolong the life of the burner brick.

[0048] Regarding the solid fiber burner brick body:

[0049] In the present invention, alumina crystal fiber raw material is pre-processed to a specific length, and fibers of different lengths are combined. Thus, an alumina crystal fiber consists of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in an alumina crystal fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%.

[0050] In some embodiments of the present invention, the combination of alumina crystal fibers is as follows:

0.01mm ≤ length < 0.05mm 25% ~ 30%;

0.05 mm ≤ length < 0.1 mm 40%;

0.1 mm ≤ length < 1 mm 30%.

[0051] In the present invention, the alumina crystal fiber is preferably one or more of alumina crystal fiber 72, alumina crystal fiber 80, and alumina crystal fiber 95. In the present invention, the mass fraction of alumina crystal fiber in the starting material is 20%. ~ 50%; and in some embodiments, 20%, 25%, or 30%.

[0052] In the present invention, the amorphous ceramic fiber raw material is pre-processed to a specific length, and fibers of different lengths are combined. Thus, an amorphous ceramic fiber consists of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in an amorphous ceramic fiber is:

0.01mm ≤ length < 0.05mm 25% ~ 35%;

0.05mm ≤ length < 0.1mm 35% ~ 45%;

0.1mm ≤ length < 1mm 25% ~ 35%.

[0053] In some embodiments of the present invention, the combination of amorphous ceramic fibers is as follows:

0.01mm ≤ length < 0.05mm 25% ~ 30%;

0.05 mm ≤ length < 0.1 mm 40%;

0.1 mm ≤ length < 1 mm 30%.

[0054] In the present invention, the raw material of the amorphous ceramic fiber is preferably high aluminum blown fiber wadding, that is, high aluminum blown fiber wadding is processed into fibers of various lengths to combine them. In the present invention, the mass fraction of amorphous ceramic fiber in the raw material is 5% ~ 20%; and in some embodiments, 5%, 10%, or 20%.

[0055] In the present invention, the fine powder filler is preferably a fine alumina powder. In the present invention, the mass fraction of the fine powder filler in the raw material of the solid fiber brick body is 20% ~ 50%; and in some embodiments 20% or 25%.

[0056] In the present invention, the fine powder filler is composed of particles of various sizes, and the mass fraction of fine powder filler particles of various sizes in the raw material of the solid fiber brick body is preferably:

filler with particle size 200~325 mesh 10% ~ 20%;

1000 mesh filler 10% ~ 30%.

[0057] In the present invention, the inorganic binder is preferably a silica sol and/or an aluminum sol. In the present invention, the mass fraction of the inorganic binder in the raw material of the whole fiber brick body is 30% ~ 50%; and in some embodiments 30%, 35% or 40%.

[0058] In the present invention, the organic binder is preferably starch. In the present invention, the mass fraction of starch in the raw material of the solid fiber brick body is 5% ~ 15%; and in some embodiments 5%, 6%, 7%, or 8%.

[0059] In the present invention, the flocculant is preferably a polyaluminum chloride. In the present invention, the mass fraction of the flocculant in the raw material of the solid fiber brick body is 1% ~ 5%; and in some embodiments 2%, 3%, 4%, or 5%.

[0060] Regarding the surface treatment of the burner brick:

[0061] In addition to the solid fiber brick body, the solid fiber burner brick of the present invention also has a coating on its surface. In the present invention, the coating is formed with a paint containing the following components in wt.%:

high temperature resistant inorganic fiber 10% ~ 50%;

reinforcing filler 10% ~ 20%;

high temperature expanding filler 5% ~ 15%;

carcass filler 7% ~ 30%;

nanopowder 3%~10%;

inorganic suspending agent 0%~20%;

inorganic binder 10% ~ 50%;

organic additive 3% ~ 15%; And

water, accounting for 10% ~ 50% of the total mass of all the above components;

[0062] The length of the high temperature resistant inorganic fiber is 0.01~1 mm.

[0063] The high temperature nanocomposite ink of the present invention is prepared by pre-treating fiber to control fiber length and adding high temperature reinforcing filler, high temperature expandable filler, nanopowder, inorganic suspending agent and other additives. Thanks to these improvements, the resulting ink with a high temperature nanocomposite structure has the following characteristics. (1) It has super high strength and compactness at high temperature, small shrinkage, no cracking at high temperature, and can withstand ultra-strong airflow attack and atmospheric erosion of a cracking furnace in the petrochemical industry; (2) The introduction of the nanopowder gives the paint a richer particle size gradation and a higher permeability when sprayed onto the surface of the fibrous lining, thereby achieving the goal of stronger adhesion to the fibrous lining; (3) By controlling the gradation of fiber length and powder particle size, and introducing an inorganic suspending agent and other additives, the paint becomes uniform and stable, delicate and smooth, and can achieve a suspension flow state similar to toothpaste in extrusion, avoiding settling and delamination during laying process. A small package can be realized, and an inverted hammer shape can be formed when fixed and rooted at the bottom of the fiber module; (4) The paint has good permeability, good adhesion to the furnace lining after spraying, and special anchoring and rooting characteristics, which makes the bonding of the paint and the furnace lining dually strong, thus effectively resisting air flow erosion and prolonging the service life of the furnace lining.

[0064] In the present invention, the starting material for the high temperature resistant inorganic fiber is preferably one or more of high alumina fibers, zirconium-containing fibers, and alumina crystal fibers. Among them, the alumina crystal fiber is preferably one or more of 72 alumina crystal fiber, 80 alumina crystal fiber, and 95 alumina crystal fiber.

[0065] In the present invention, the high temperature resistant inorganic fiber is a recycled fiber, and the present invention controls the length of the fiber through processing. In the present invention, the length of the obtained heat-resistant inorganic fiber is 0.01~1 mm; and the diameter of the heat-resistant inorganic fiber is preferably 1~6 µm.

[0066] In the present invention, the mass fraction of the heat-resistant inorganic fiber in the ink is 10%~50%, preferably 15%~30%; and in some embodiments of the present invention, 15%, 20%, 25%, or 30%.

[0067] In the present invention, the reinforcing filler is a high temperature resistant reinforcing filler, preferably one or more of acicular microsilica powder and pyrophyllite powder. Among them, the particle aspect ratio of the acicular microsilica powder is preferably (15~20):1. The particle size of the pyrophyllite powder is preferably 200~300 mesh. In the present invention, there is no particular restriction on the source of high temperature reinforcing filler as long as it is a common commercial product.

[0068] In the present invention, the mass fraction of the reinforcing filler in the paint is 10%~20%; and in some embodiments, 10%, 13%, 15%, or 20%.

[0069] In the present invention, the high temperature expanding filler is preferably one or more of kyanite and sillimanite powders. In the present invention, there is no particular restriction on the source of the high temperature expandable filler as long as it is a common commercial product. In the present invention, the mass fraction of the high temperature expanding filler in the paint is 5% ~ 15%; and in some embodiments, 5%, 8%, or 12%.

[0070] In the present invention, the carcass filler is a high temperature resistant carcass filler, preferably one or more of alumina powder, mullite powder, zircon powder, and corundum powder. In the present invention, the particle size of the carcass filler is preferably 300-1000 mesh. In the present invention, there is no particular restriction on the source of the carcass filler as long as it is a common commercial product.

[0071] In the present invention, the mass fraction of the carcass filler in the paint is 7%~30%; and in some embodiments, 7%, 10%, or 15%.

[0072] In the present invention, the nanopowder is preferably one or more of nanosilica and nanoalumina powders. In the present invention, the particle size of the nanopowder is preferably 1~100 nm. In the present invention, there is no special limitation on the source of the nanopowder as long as it is a common commercial product.

[0073] In the present invention, the mass fraction of nanopowder in the paint is 3%~10%; and in some embodiments, 3%, 5%, or 8%.

[0074] In the present invention, the inorganic suspending agent is preferably bentonite. In the present invention, the mass fraction of the inorganic suspending agent in the paint is 0% ~ 20%; and in some embodiments, 0% or 5%.

[0075] In the present invention, the inorganic binder is selected from one or more of aluminum sol, aluminum dihydrogen phosphate, and silica sol. In the present invention, the mass fraction of the inorganic binder in the paint is 10%~50%; and in some embodiments, 25%, 37%, 40%, or 41%.

[0076] In the present invention, the organic additive is preferably one or more of an organic binder, an antiseptic, and an antifreeze; and more preferably the organic additive is an organic binder, antiseptic and antifreeze. Among them, the organic binder is preferably one or more of starch, dextrin and cellulose. The antiseptic is preferably a biocide. The antifreeze is preferably ethylene glycol.

[0077] In the present invention, the mass fraction of the organic additive in the paint is 3%~15%; and in some embodiments, 3% or 5%.

[0078] In the present invention, the total weight of the aforementioned high temperature resistant inorganic fiber, reinforcing filler, high temperature expansion filler, carcass filler, nanopowder, inorganic suspending agent, inorganic binder and organic additive is preferably 100%. In addition to the above ingredients, the paint system contains water; in the present invention, the amount of water is 10%-50% of the total amount of all the above components except water; and in some embodiments, 15%, 25%, 30%, or 35%.

[0079] The high-temperature nanocomposite paint of the present invention uses fibers of a specific length, and also introduces a specific reinforcing filler and a high-temperature expandable filler, so that it has ultra-high strength at high temperatures without cracking caused by shrinkage at high temperature. In addition to this, certain frame fillers and nanostructured materials are introduced, and the synergistic effect between the above materials makes the state of the paint uniform and stable, avoiding settling and delamination during the laying process. During high-temperature use, the paint adheres strongly to the furnace lining, has little high-temperature shrinkage, and has a hard-crust barrier with ultra-high strength. The paint has small shrinkage after high temperature firing, no cracking, and strong bonding with the furnace lining, and high strength after high temperature firing, which can effectively resist air flow erosion and atmospheric erosion during bottom, side and top firing, thus protecting fiber module against corrosion by the external environment and destruction due to brittleness, and preventing heat loss of the furnace during high temperature operation, so as to prolong the service life of the furnace lining and reduce the temperature of the furnace outer wall, achieving the goal of energy saving and consumption reduction. The high-temperature nanocomposite paint of the present invention can be used as a special paint for the whole fiber structure of an ethylene cracking furnace, and has super high strength, strong adhesion to the fiber lining and a special adhesion state, thus realizing the convenience of construction and playing a key role in replacing the brick wall with whole fiber structure.

[0080] In the present invention, the above ink can be prepared in the following way:

[0081] S1. mixing a high temperature resistant inorganic fiber, an inorganic binder and water to obtain a fiber dispersion;

[0082] S2. mixing the fiber dispersion with the high temperature expandable filler, reinforcing filler and carcass filler to form a slurry; And

[0083] S3. mixing suspension with nanopowder, inorganic suspending agent and organic additive to obtain paint.

[0084] Among them, in step S1, the mixing is preferably mixing with stirring; the mixing time is preferably 10~30 minutes. In step S2, the mixing is preferably mixing with stirring; the stirring time is preferably 3~5 minutes. In step S3, the mixing sequence is preferably as follows: first, the nanopowder is added to the suspension, mixed for 3-5 minutes with stirring; then an inorganic suspending agent is added and mixed for 5~10 minutes with stirring; and finally, the organic additive is added and mixed for 10~20 minutes with agitation to obtain a coating.

[0085] In the solid fiber burner brick of the present invention, the thickness of the solid fiber brick body is preferably 250~550 mm; and the coating thickness is preferably 5~10 mm. In the present invention, the coating is applied to all outer surfaces of the all-fiber body of the brick.

[0086] The present invention also provides a process for producing a solid fiber burner brick as described in the above technical solutions, comprising:

[0087] a) mixing alumina crystal fiber, amorphous ceramic fiber, inorganic binder, fine powder filler, organic binder and water to form a slurry;

[0088] b) mixing the slurry with the flocculant and then performing vacuum filtration and pressing to obtain a wet preform;

[0089] c) drying the wet preform to obtain a dry preform; And

[0090] d) applying paint to the surface of the dry blank and drying to obtain a solid fiber burner brick.

[0091] Regarding step a):

[0092] In the present invention, the fibers are pre-treated on a blending machine to control the length of the fibers, and then the fibers with different lengths are combined and placed in the original material for use. Fiber types and lengths of alumina crystals and amorphous ceramic fibers, as well as ratios of fibers with different lengths, etc. correspond to those described in the above technical solutions, and will not be repeated here. The types and amounts of inorganic binder and fine powder filler are also those described in the above technical solutions and will not be repeated here.

[0093] Since the volume of the burner brick is relatively large, the forming thickness is more than 450 mm, and it is difficult to increase the thickness of the suction filtration to half the thickness, so that ordinary suction filtration is not available to achieve the effect. The present invention controls the fiber length gradation and powder strength, and also increases the filterability of the pulp suction. Prior to wet spinning, the fiber is pre-treated to a predetermined length range. The length of the fiber is controlled so that it has a certain gradation, which solves the problem that it is difficult to control the length of the fiber when it is stirred in water, causing the wadding to become too thin to be vacuum filtered, or too thick, which leads to uneven suction filtration, as well as uneven internal structure of the wadding blank due to the too low bulk density of the wadding blank during the molding process. The gradation of the powder filler particles is controlled, which also contributes to a better formation of the wadded preform when the wet preform is subjected to vacuum filtration.

[0094] In the present invention, when the above materials are mixed, the mixing sequence is preferably as follows: alumina crystal fiber, amorphous ceramic fiber, inorganic binder, fine powder filler, and organic binder are sequentially added to water in certain proportions and mixed until uniform . The present invention is not particularly limited to the mixing method, provided that the materials are mixed in a conventional manner well known to those skilled in the art. In the present invention, it is preferable to control the concentration of the suspension obtained by mixing so that it is 1 ~ 15 mass%.

[0095] Regarding step b):

[0096] In the present invention, the suspension obtained in step a) is mixed with a flocculant to facilitate filtration. After adding the flocculant to the slurry, the fiber, fine powder filler and inorganic binder flocculate together, making the water clear. In the present invention, the temperature at which the flocculant is added is preferably 5~40°C, and the time is preferably 1~5 minutes. The flocculated slurry is placed in a forming tank and then vacuum filtered to remove excess liquid. After vacuum filtration molding as described above, a wet preform is obtained. The present invention differs from the prior art molding die in the above-described vacuum filtering molding. In the traditional molding method, the material can only be fed from above to be molded, while in the present invention, side suction is added, which makes the preform more uniform and compact.

[0097] In the present invention, a pressing process is added during the molding process to increase the thickness of the mold die. After the pulp fills the forming die, the pressing process is added to the final drying process, and the wet billet is pressed during vacuum filtration, so that the wet billet becomes more compact and uniform, ensuring the bulk density and strength of the cotton blank.

[0098] Regarding step c):

[0099] In the present invention, the drying temperature is preferably 80~120°C, and the drying time is preferably 30~120 hours. After drying, a dry preparation is obtained.

[00100] Regarding step d):

[00101] In the present invention, the paint application method preferably comprises: first punching holes in the surface of the dry workpiece and supplying glue to the holes to root the paint, and then applying paint to the entire surface of the dry workpiece. The present invention is not particularly limited to the ink perforating and rooting operations as long as they are carried out in accordance with conventional operations in the art. For example, a rectangular burner brick (length 500 mm × width 500 mm × height 320 mm) includes six surfaces: top, bottom, left, right, front, and back. The punching of the holes can be carried out in particular on the surface of the fire-facing wall and side walls, along the vertical direction of the fire-facing surface and side walls. Starting from the edge of the surface facing the fire, punching starts with a 50 mm square, with a hole every 80 mm, 5 holes in a row, 5 rows, 35 holes in total. The side wall is also punched with this method, with approximately 24 holes on each of the four sides, evenly spaced along the body of the brick. The punching diameter is 10mm and the depth is 20~50mm. After punching the holes, it is pasted into the hole for rooting the paint. The paint is the paint described in the above technical solution, and its description will not be repeated here. After that, paint is applied to the surface of the dry workpiece and dried to form a coating. In the present invention, the drying temperature is preferably 80~120°C, the drying time is preferably 10~48 hours; and the thickness of the formed coating is preferably 5~10 mm. After the above processing, an all-fiber burner brick is obtained.

[00102] Conventional special-shaped high-temperature whole fiber products use surface sizing with an inorganic binder to increase the strength of the wadding blank, which cannot significantly protect the fiber of the cotton wadding blank from adverse environmental conditions. However, the surface coating fundamentally eliminates the contact of the harsh environment with the whole-fiber billet, thereby significantly extending the life of the burner brick.

[00103] The solid fiber burner brick of the present invention has the following beneficial effects: the combination of materials of the brick body can increase the bulk density of the product and improve the suction filterability of the fibrous wadding preform, and promote molding and improve the strength of the preform. The surface of the brick body is further provided with a coating, which can effectively protect the fiber of the brick body from harsh conditions, improve its high temperature resistance, and help prolong the service life of the burner brick when it is used as the burner brick for ethylene cracking furnace.

[00104] To further understand the present invention, its preferred embodiments will be described below along with examples. However, it should be understood that these descriptions are only intended to further illustrate the features and advantages of the present invention and not to limit its claims.

[00105] Example 1

[00106] 1.1 Brick Body Raw Material Formula

Alumina crystal fibers 72: 20%;

Amorphous ceramic fiber 20%;

Fine powder filler 20%;

Inorganic binder - silica sol: 30%;

Organic binder - starch: 8%;

Flocculant - polyaluminum chloride: 2%;

[00107] Among them:

[00108] The combination of silica crystal fiber lengths was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00109] The combination of the lengths of the amorphous ceramic fiber and the blown fiber with a high aluminum content was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00110] The fine powder filler was fine alumina powder, and the combination of particle sizes thereof was: 200~325 mesh 10%, 1000 mesh 10%.

[00111] 1.2 Paint formula

High temperature resistant inorganic fiber: 15%;

High-temperature reinforcing filler - acicular microsilica powder: 10%;

Expanding at high temperature filler - kyanite powder: 12%;

High temperature frame filler - alumina powder: 10%;

Nanopowder - nanosilica: 5%;

Inorganic binder - aluminum sol: 40%;

Organic additive - 2% cellulose powder, 0.7% biocide, 0.3% ethylene glycol: 3%;

Inorganic suspending agent - bentonite: 5%;

Water, constituting 15% of the total mass of all the above components.

[00112] Among them, the starting fiber of the high temperature resistant inorganic fiber was a high alumina fiber, which was processed into a short fiber. The resulting fiber had a length of 0.01~1 mm and a diameter of 1~5 µm.

[00113] Paint preparation

[00114] The high temperature resistant inorganic fiber was weighed and added to the mixer. The inorganic binder and water were weighed, added and mixed for 20 minutes to completely wet and disperse the fibers. Then, the high-temperature expanding filler, the reinforcing filler and the carcass filler were successively added. After the addition, the mixture was stirred for 5 minutes for complete dispersion. Then the nanopowder was added and stirred for 5 min. The inorganic suspending agent was added and stirred for 10 minutes to fully expand and play the suspending role. Finally, organic additives were added and mixed for 20 minutes to obtain a paint.

[00115] 1.3 Brick burner preparation

[00116] S1. Alumina crystal fiber and amorphous ceramic fiber with various length gradations, inorganic binder, fine powder filler and organic binder were added to water in appropriate proportions and mixed uniformly to obtain a slurry with a concentration of 5 wt.%.

[00117] S2. The flocculant was added to the slurry to flocculate other materials until the water became clear to obtain a flocculated material.

[00118] S3. The flocculated material was placed in a forming tank and vacuum filtration was performed. After molding, the wet billet was pressed to a thickness of 350 mm and transported to a drying chamber for drying at a temperature of 120° C. for 120 hours to obtain a dry billet.

[00119] S4. The dry billet was cut to size with a length of 490 mm × a width of 480 mm × a height of 310 mm.

[00120] S5. Paint was applied to the surface of the dry workpiece, and the specific steps are: punching holes on the surface of the dry workpiece → paint rooting → applying to the surface of the dry workpiece → drying. The hole diameter was 10 mm and the depth was 30 mm. The coating thickness was 10 mm; the drying temperature was 120°C for a duration of 24 hours. After the above processing, a burner brick was obtained.

[00121] Example 2

[00122] 1.1 Brick Body Raw Material Formula

Alumina crystal fibers 80: 25%;

Amorphous ceramic fiber 5%;

Fine powder filler 25%;

Inorganic binder - silica sol: 35%;

Organic binder - starch: 7%;

Flocculant - polyaluminum chloride: 3%;

[00123] Among them:

[00124] The combination of silica crystal fiber lengths was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00125] The combination of the lengths of the amorphous ceramic fiber and the blown fiber with a high aluminum content was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00126] The fine powder filler was fine alumina powder, and the combination of particle sizes thereof was: 200~325 mesh 15%, 1000 mesh 10%.

[00127] 1.2 Paint formula

High temperature resistant inorganic fiber: 20%;

High-temperature reinforcing filler - pyrophyllite powder: 13%;

Expanding at high temperature filler - sillimanite: 5%;

High-temperature frame filler - mullite powder: 15%;

Nanopowder - nanoalumina powder: 3%;

Inorganic binder - silica sol: 41%;

Organic additive - 2% starch powder, 0.7% biocide, 0.3% ethylene glycol: 3%;

Water, constituting 25% of the total mass of all of the above components.

[00128] Among them, the original fiber of the high temperature-resistant inorganic fiber was a zirconium-containing fiber, which was processed into a short fiber. The resulting fiber had a length of 0.01~2 mm and a diameter of 1~6 µm.

[00129] Paint preparation: Same as Example 1.

[00130] 1.3 Burner Brick Preparation: Same as Example 1.

[00131] Example 3

[00132] 1.1 Brick Body Raw Material Formula

Alumina crystal fibers 80: 30%;

Amorphous ceramic fiber 5%;

Fine powder filler 20%;

Inorganic binder - silica sol: 35%;

Organic binder - starch: 5%;

Flocculant - polyaluminum chloride: 5%;

[00133] Among them:

[00134] The combination of silica crystal fiber lengths was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00135] The combination of the lengths of the amorphous ceramic fiber and the blown fiber with a high aluminum content was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00136] The fine powder filler was fine alumina powder, and its particle size combination was: 200~325 mesh 10%, 1000 mesh 10%.

[00137] 1.2 Paint Formula

High temperature resistant inorganic fiber: 25%;

High-temperature reinforcing filler - acicular microsilica powder: 15%;

Expanding at high temperature filler - kyanite powder: 8%;

High-temperature framework filler - zircon powder: 7%;

Nanopowder - nanoalumina powder: 5%;

Inorganic binder - liquid aluminum dihydrogen phosphate: 37%;

Organic additive - 2% dextrin powder, 0.7% biocide, 0.3% ethylene glycol: 3%;

Water, constituting 30% of the total mass of all the above components.

[00138] Among them, the original fiber of the high temperature resistant inorganic fiber was a 72 alumina crystal fiber, which was processed into a short fiber. The resulting fiber had a length of 0.01~3 mm and a diameter of 1~6 µm.

[00139] Paint preparation: Same as Example 1.

[00140] 1.3 Burner Brick Preparation: Same as Example 1.

[00141] Example 4

[00142] 1.1 Brick Body Raw Material Formula

Alumina crystal fibers 80: 20%;

Amorphous ceramic fiber 10%;

Fine powder filler 20%;

Inorganic binder - silica sol: 40%;

Organic binder - starch: 6%;

Flocculant - polyaluminum chloride: 4%;

[00143] Among them:

[00144] The combination of silica crystal fiber lengths was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00145] The combination of the lengths of the amorphous ceramic fiber and the blown fiber with a high aluminum content was: 0.01~0.05mm 30%, 0.05~0.1mm 40%, 0.1~1mm 30%.

[00146] The fine powder filler was fine alumina powder, and the combination of particle sizes thereof was: 200~325 mesh 10%, 1000 mesh 10%.

[00147] 1.2 Paint formula

High temperature resistant inorganic fiber: 30%;

High-temperature reinforcing filler - pyrophyllite powder: 20%;

Expanding at high temperature filler - sillimanite: 5%;

High-temperature frame filler - corundum powder: 7%;

Nanopowder - nanoalumina powder: 8%;

Inorganic binder - aluminum sol: 25%;

Organic additive - 3.5% cellulose powder, 1% biocide, 0.5% ethylene glycol: 5%;

Water, constituting 35% of the total mass of all the above components.

[00148] Among them, the original fiber of the high temperature resistant inorganic fiber was a 95 alumina crystal fiber, which was processed into a short fiber. The resulting fiber had a length of 0.01~3 mm and a diameter of 1~6 µm.

[00149] Paint preparation: Same as Example 1.

[00150] 1.3 Burner Brick Preparation: Same as Example 1.

[00151] Example 5

[00152] The characteristics of the burner bricks obtained in Examples 1~4 were tested, and the prior art solid fiber burner brick product (manufactured by Unifrax Co., Ltd.) was used as a reference for performance comparison. The results are shown in Table 1.

Table 1. Characteristics of the brick burner of Examples 1-4

Tensile strength at room temperature
MPa Compressive strength at room temperature
(Compression 10%) MPa Compressive strength after firing,
1350°C×3 hour
(Compression 10%) MPa Linear heat shrinkage
1350°C×3 hour
% Example 1 1.17 0.6 0.773 +0.2 Example 2 1.10 0.65 0.85 +0.3 Example 3 1.15 0.70 0.80 +0.5 Example 4 1.2 0.75 0.95 +0.8 Control sample 0.93 0.38 0.682 -2.4

[00153] It can be seen from the above test results that, compared with the existing solid fiber burner brick, the burner brick of the present invention can significantly improve tensile strength and compressive strength at room temperature, as well as compressive strength at high temperature. , and reduce linear shrinkage when heated, greatly improving the performance of the brick burner.

[00154] The above description of the examples is used only to facilitate understanding of the method and the basic concept of the present invention. Various modifications to the embodiments will be apparent to those skilled in the art. The general principle defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but should have the broadest scope consistent with the principles and novel features disclosed herein.

Claims (54)

1. All-fiber burner brick, containing a solid-fiber brick body and a coating applied to its surface; in which the all-fiber brick body is obtained from the source material containing the following components, wt.%: fiber from alumina crystals 20 - 30; amorphous ceramic fiber 5 - 20; fine powder filler 20 - 25; inorganic binder 30 - 40; organic binder 5 - 15; flocculant 1 - 5; alumina crystal fiber consists of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in alumina crystal fiber is: 0.01mm ≤ length < 0.05mm 25% ~ 35%; 0.05mm ≤ length < 0.1mm 35% ~ 45%; 0.1mm ≤ length < 1mm 25% ~ 35%; amorphous ceramic fiber consists of a combination of fibers of different lengths, and the mass fraction of fibers of different lengths in an amorphous ceramic fiber is: 0.01mm ≤ length < 0.05mm 25% ~ 35%; 0.05mm ≤ length < 0.1mm 35% ~ 45%; 0.1mm ≤ length < 1mm 25% ~ 35%. 2. The brick according to claim 1, wherein the fine powder filler is a fine alumina powder; fine powder filler consists of particles of various sizes, and the mass fraction of fine powder filler particles of various sizes in the raw material is: filler with particle size 200~325 mesh 10~20%; filler with particle size 1000 mesh 10~30%. 3. A brick according to claim 1, wherein the inorganic binder is a silica sol and/or an aluminum sol; the organic binder is starch. 4. Brick according to claim 1, in which the flocculant is a polyaluminum chloride; thickness of solid brick body is 250~550mm; coating thickness is 5~10mm. 5. Brick according to claim 1, in which the coating is formed by a paint containing the following components, wt.%: high temperature resistant inorganic fiber 10~50%; reinforcing filler 10 ~ 20%; high temperature expanding filler 5~15%; carcass filler 7 ~ 30%; nanopowder 3~10%; inorganic suspending agent 0~20%; inorganic binder 10~50%; organic additive 3~15%; And water, constituting 10 ~ 50% of the total mass of all the above components; in which the length of the high temperature resistant inorganic fiber is 0.01~1mm. 6. Brick according to claim 5, in which in the paint: the nanopowder is selected from one or more nanosilica and nanoalumina powders; the high temperature resistant inorganic fiber is selected from one or more high aluminum content fibers, zirconium-containing fibers, and alumina crystal fibers. 7. Brick according to claim 5, in which in the paint: the reinforcing filler is selected from one or more powders of acicular microsilica and pyrophyllite; the high temperature expandable filler is selected from one or more kyanite and sillimanite powders; the frame filler is selected from one or more powders of alumina, mullite, zircon and corundum. 8. Brick according to claim 5, in which in the paint: the inorganic suspending agent is bentonite; the inorganic binder is selected from one or more of aluminum sol, aluminum dihydrogen phosphate, and silica sol; the organic additive is selected from one or more of an organic binder, an antiseptic, and an antifreeze. 9. The method of obtaining a solid-fiber burner brick according to any one of paragraphs. 1-8 containing: a) mixing alumina crystal fiber, amorphous ceramic fiber, inorganic binder, fine powder filler, organic binder and water to form a slurry; b) mixing the slurry with the flocculant and then performing vacuum filtration and pressing to obtain a wet preform; c) drying the wet preform to obtain a dry preform; And d) applying paint to the surface of a dry workpiece and drying to obtain a solid-fiber burner brick. 10. The method according to p. 9, in which at stage a) the concentration of the suspension is 1 ~ 15 wt.%; in step c), pressing is carried out so that the thickness of the workpiece reaches 250~550 mm.