Preparation technology of long fiber interwoven structure tubular furnace

Abstract

The invention discloses a preparation process of a tubular furnace with a long fiber interlaced structure. The tubular furnace with a long fiber interlaced structure comprises a tubular furnace and a plurality of resistance wires arranged inside the tubular furnace. The inner wall of the tubular furnace is provided with a plurality of resistance wire grooves for installing the resistance wires. The preparation of the tubular furnace with a long fiber interlaced structure comprises the following steps: S1 material preparation; S2 cutting; S3 opening resistance wire grooves; S4 molding; S5 hardening; S6 calcination; S7 opening lead wire grooves; S8 resistance wire installation; S9 filling and repairing the lead wire grooves; S10: drying; S11: furnace processing; S12 surface coating treatment; S13 testing. The invention can prepare a buried wire tubular furnace with a long fiber interlaced structure without increasing the cost investment. The process is simple, the cost is low, and the performance is superior, especially in that the overall stress resistance is strong. The long fiber interlaced structure and the resistance wire are firmly overlapped, so that the resistance wire will not be easily loosened or fallen off.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment of photovoltaic silicon wafers, and in particular to a preparation process of a tubular furnace with a long fiber interlaced structure. Background Art

[0002] Photovoltaic power generation is a technology that uses the photovoltaic effect of semiconductor interfaces to directly convert light energy into electrical energy. The main principle is the photoelectric effect of semiconductors. It has obvious advantages and may become the number one clean energy in the future.

[0003] In the prior art, the production process of photovoltaic cells: silicon wafers are made through cleaning and texturing, diffusion (P / N junction), passivation coating, printing and sintering, among which the diffusion (P / N junction) equipment / process is the key to improving the thermal treatment of silicon wafers and the photoelectric conversion efficiency of photovoltaic cells. After the polycrystalline silicon is cast, broken, sliced ​​and other procedures, it is made into silicon wafers to be processed. Trace amounts of boron, phosphorus, etc. are doped and diffused on the silicon wafers to form P / N junctions.

[0004] Diffusion furnace is an important part of silicon wafer heat treatment. In the existing technology, vacuum formed resistance wire tube furnace (buried wire furnace) is the most common, with high working temperature (700℃~1200℃), and the furnace is divided into multiple temperature zones for precise monitoring, so that the high temperature field in the furnace is more uniform (accuracy ±0.5~1℃), with better thermal insulation effect and high energy efficiency and other advantages. The market demand is huge. The current photovoltaic market in China alone has a demand of about 3,000 to 5,000 tubes / month for vacuum formed resistance wire tube furnace (buried wire furnace).

[0005] However, the existing vacuum forming resistance wire tube furnace also has its shortcomings, mainly manifested in:

[0006] The vacuum-formed tubular furnace cores are all made of short-fiber vacuum forming. The furnace core structure produced by this short fiber has poor thermal shock resistance. During actual operation, intermittent heating and cooling is prone to shrinkage, deformation, and cracking. Since the temperature inside the tubular furnace is required to be uniform, multiple sections of resistance wire are evenly and parallelly embedded in the inner wall of the furnace core. The distance between adjacent resistance wires is only about 20mm. When the resistance wire is heated, the local temperature around it is more than 50°C higher than the furnace temperature. The insulation material between adjacent resistance wires is more likely to crack, powder, gradually loosen, and fall off, causing the resistance wire to shift and pop out at high temperature.

[0007] In order to improve the above shortcomings, the following technical directions can be considered:

[0008] 1. Use polycrystalline fiber with higher temperature resistance as raw material for producing vacuum formed tubular furnace, and improve the thermal shock resistance by improving the temperature resistance of the material, but the corresponding cost will be greatly increased;

[0009] 2. The long fiber and dry forming process are used to make the tubular furnace core, which changes the internal fiber structure of the furnace core. Through the advantages of long fibers and their structure, the thermal shock resistance of the furnace core is improved without increasing the temperature resistance level of the material. The problems of cracking and resistance wire shedding that occur when the short fiber vacuum-formed tubular furnace core works at high temperatures are solved, effectively extending the service life of the furnace core. Summary of the invention

[0010] In view of the problems that the buried wire tubular furnace core formed by the existing short fiber vacuum forming process has poor thermal shock resistance and unstable overlap with the resistance wire, the present invention provides a preparation process of a tubular furnace core with a long fiber interlaced structure. Without increasing the cost investment, a buried wire tubular furnace core with a long fiber structure is prepared, and the structural advantages of the long fiber are utilized to improve the thermal shock resistance of the furnace core and the overlap stability of the resistance wire and the furnace core.

[0011] In order to solve the above technical problems, the present invention proposes a preparation process of a long fiber interwoven structure tubular furnace, wherein the long fiber interwoven structure tubular furnace comprises a tubular furnace body and a plurality of resistance wires arranged inside the tubular furnace, and the inner wall of the tubular furnace body is provided with a plurality of resistance wire grooves for installing the resistance wires. The preparation of the long fiber interwoven structure tubular furnace comprises the following steps:

[0012] S1 material preparation: select inorganic refractory fiber blocks with a bulk density of 130-240K and a long fiber interwoven structure or fiber blanket blocks with a bulk density of 128-180K as raw materials for preparing the tubular furnace body;

[0013] S2 cutting: according to the size of the tubular furnace body to be prepared, a blank having a length corresponding to the outer perimeter of the tubular furnace body, a width corresponding to the height of the tubular furnace body, and a thickness corresponding to the wall thickness of the tubular furnace body is cut from the inorganic refractory fiber block or the fiber blanket block;

[0014] S3: Opening resistance wire grooves: Lay the blank flat, then carve a number of resistance wire grooves on the top surface of the blank, cut wedges at both ends of the blank for staggered splicing, and clamp a shaping die in each resistance wire groove for limiting and protecting the resistance wire groove and the partition between two adjacent resistance wire grooves;

[0015] S4 forming: according to the size of the tubular furnace body to be prepared, the corresponding tube rolling mold is selected, and the side engraved with the resistance wire groove is the inner side. The blank is rolled on the tube rolling mold so that the end is connected to the end to form the blank prototype of the tubular furnace body, and the end connection of the blank is bonded or sutured with high temperature resistant wire;

[0016] S5 Hardening: Place the tube coiling mold together with the tube furnace body blank on it in a dipping tank for dipping. After dipping, take it out, evacuate it and place it in a drying oven for drying.

[0017] S6 calcination: the shaping mold and the tube coiling mold are removed from the molds respectively, and then the tubular furnace body is calcined at 650-1200°C for 1-3h to form the tubular furnace body;

[0018] S7: Opening lead grooves: using the ends of one group of adjacent resistance wire grooves in the tubular furnace body as the positive lead outlet and the negative lead outlet, opening the grooves to the outside of the tubular furnace, pre-setting the positive lead interface and the negative lead interface on the outer edge of the tubular furnace, and then opening two lead grooves of the positive lead outlet-positive lead interface and the negative lead outlet-negative lead interface on the outer periphery of the blank respectively;

[0019] Installation of S8 resistor wire: first fold the resistor wire lead wire according to the size and angle of the lead wire slot, then pre-brush high-temperature adhesive evenly in each resistor wire slot, then insert the resistor wires into the resistor wire slots one by one, and press the positive and negative lead wires into the corresponding lead wire slots respectively;

[0020] S9 lead slot filling and repair: Use filler with temperature resistance not less than 1500℃ to fill and repair the resistance wire lead slot;

[0021] S10: Drying: placing the furnace body in a drying furnace for drying, and cooling after drying;

[0022] S11: Furnace processing: Process the two ends and surface of the dried tubular furnace body to make its size meet the requirements;

[0023] S12 Surface coating treatment: Use paint to coat the surface of the tubular furnace body.

[0024] S13 test: Test the weight and size of the tubular furnace body, and connect the power supply to check whether the resistance wire is conductive or short-circuited.

[0025] Furthermore, the steps of preparing the inorganic refractory fiber block include:

[0026] Step 1: Weigh the raw materials by weight: 33-48 parts of aluminum oxide, 45-60 parts of silicon dioxide, and 0.1-1 parts of additives, wherein the additives are composed of coconut oil diethanolamide and silica sol, with coconut oil diethanolamide accounting for 85-95% and silica sol accounting for 15-5%, and mix and melt the raw materials according to the proportion;

[0027] Step 2: Spinning the molten raw material into fibers, and spraying additives on the fibers in a spraying manner through a material adding device during spinning;

[0028] Step 3: The fibers are collected and needle punched to form bulk fibers.

[0029] Furthermore, the shaping mold is a strip structure, and L-shaped ears for limiting the position against the inner wall of the tubular furnace body are symmetrically arranged on both sides of its top surface. The shaping mold is inserted into the resistance wire groove with the bottom surface facing inward and the top surface facing outward.

[0030] Furthermore, the tube rolling mould has a vacuum box tubular structure, and a plurality of through holes are evenly opened on the side wall thereof.

[0031] Furthermore, in step S4 and step S8, the high temperature bonding of the blanks which are connected end to end and the resistance wire slots which are pre-brushed has a high temperature resistance of not less than 1400°C.

[0032] Furthermore, the dipping process in step S5 uses silica sol, and the addition ratio of silica sol to water is 6:4, or 7:3, or 8:2, or 9:1 or original glue.

[0033] Furthermore, in step S5, the dipping time is 5 to 30 seconds, the drying temperature after vacuuming is 120 to 180° C., and the drying time is 3 to 10 hours.

[0034] Furthermore, wire grooves for clamping with two adjacent groups of resistance wire connecting sections are respectively provided at both ends of the partition between each two adjacent resistance wire grooves.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] Without increasing the cost investment, an buried wire tubular furnace with a long fiber interwoven structure can be prepared. The process is simple, the cost is low, and the performance is superior, especially in terms of strong overall stress resistance. The long fiber interwoven structure is firmly overlapped with the resistance wire, so that the resistance wire will not loosen or fall off easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 Schematic diagram of the three-dimensional structure of the long fiber interwoven structure tubular furnace of the present invention,

[0039] Figure 2 It is a structural schematic diagram of a tubular furnace body 1.

[0040] Figure 3 It is a schematic diagram of the structure of the tubular furnace body 1 in a flat state.

[0041] Figure 4 is a schematic diagram of the structure of the shaping mold 3,

[0042] Figure 5 is a schematic diagram of the structure of the tube rolling mold 4,

[0043] The reference numerals are as follows:

[0044] The tubular furnace body 1, the resistance wire slot 11, the resistance wire 2, the shaping mold 3, and the tube rolling mold 4. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present invention.

[0046] Please refer to Figures 1 to 5 The present invention provides a preparation process of a long fiber interwoven structure tubular furnace, the long fiber interwoven structure tubular furnace comprising a tubular furnace body 1 and a plurality of resistance wires 2 evenly arranged inside the tubular furnace, the inner wall of the tubular furnace body 1 is evenly provided with a plurality of resistance wire grooves 11 for installing the resistance wires, and the preparation of the long fiber interwoven structure tubular furnace comprises the following steps:

[0047] S1 material preparation: select inorganic refractory fiber blocks with a bulk density of 130-240K and a long fiber interwoven structure or fiber blanket blocks with a bulk density of 128-180K as raw materials for preparing the tubular furnace body 1. The present invention uses long-fiber inorganic refractory fiber blocks or fiber blanket blocks as raw materials because the inorganic refractory fiber blocks or fiber blanket blocks have long fiber structures, and the preparation process includes a needle punching process. The needle punching process can interweave the long fibers therein, and the long fiber interwoven structure has very good stress resistance, wherein:

[0048] The steps for preparing the inorganic refractory fiber block include:

[0049] Step 1: Weigh the raw materials by weight: 33-48 parts of aluminum oxide, 45-60 parts of silicon dioxide, and 0.1-1 part of additives, and mix and melt the raw materials in proportion;

[0050] Step 2: Spinning the melted raw material into fibers, and spraying additives on the fibers in a spraying manner through a material adding device during spinning, wherein the additives are composed of coconut oil diethanolamide and silica sol, wherein the coconut oil diethanolamide accounts for 85-95% and the silica sol accounts for 15-5%;

[0051] Step 3: Collect the fibers and conduct a needle punching process to produce large fiber blocks;

[0052] S2 cutting: according to the size of the tubular furnace body 1 to be prepared, a blank having a length corresponding to the outer perimeter of the tubular furnace body 1, a width corresponding to the height of the tubular furnace body 1, and a thickness corresponding to the wall thickness of the tubular furnace body 1 is cut from the inorganic refractory fiber block or the fiber blanket block;

[0053] S3: Open the resistance wire groove: lay the blank flat, then carve a number of resistance wire grooves 11 on the top surface of the blank, cut wedges at both ends of the blank for staggered splicing, and clamp a shaping mold 3 in each resistance wire groove 11 for limiting and protecting the resistance wire groove 11 and the partition between two adjacent resistance wire grooves 11, wherein:

[0054] The shaping mold 3 of the present invention is a strip-shaped structure, and L-shaped ears 31 are symmetrically arranged on both sides of its top surface to limit the position against the inner wall of the furnace. The bottom surface of the shaping mold faces inwards and the top surface faces outwards to be inserted into the resistance wire groove. In order to facilitate demolding, the bottom surface of the shaping mold is set to an arc structure;

[0055] S4 forming: according to the size of the tubular furnace body 1 to be prepared, a corresponding tube rolling mold 4 is selected, and the side engraved with the resistance wire groove 11 is used as the inner side. The blank is rolled on the tube rolling mold 4 so that the end to end is connected to form the blank prototype of the tubular furnace body 1, and the end to end connection of the blank is bonded or sewn with a high temperature resistant thread. The bonding is carried out with a high temperature adhesive with a high temperature resistance of not less than 1400°C. There are many types of adhesives on the market. As long as the temperature resistance level meets the requirements of the present invention, it is environmentally friendly and the price is appropriate, it can be considered, and the present invention does not limit it;

[0056] in addition, Figure 5 The structure of the commonly used tube rolling mold 4 is that a plurality of through holes are evenly opened on the side wall. The tube rolling mold 4 of the present invention preferably has a vacuum box tubular structure. Figure 5 On the basis of the vacuum box, both ends are closed to make it into a box structure that can be vacuumed.

[0057] S5 hardening: placing the tube coiling mold 4 together with the tubular furnace body 1 blank thereon in a dipping tank for dipping, wherein silica sol is used for dipping, and the addition ratio of silica sol to water is 6:4, or 7:3, or 8:2, or 9:1 or original glue, and the dipping time is 5 to 30 seconds;

[0058] After dipping, take out the mixture, evacuate it and place it in a drying oven for drying at a temperature of 120 to 180°C for 3 to 10 hours.

[0059] S6 calcination: the shaping mold and the tube coiling mold are removed from the molds respectively, and then the tube furnace body 1 blank is calcined at a temperature of 650 to 1200° C. for 1 to 3 hours to form the tube furnace body 1;

[0060] S7: Opening lead grooves: using the ends of one group of adjacent resistance wire grooves in the tubular furnace body 1 as the positive lead outlet and the negative lead outlet, opening the grooves to the outside of the tubular furnace, pre-setting the positive lead interface and the negative lead interface on the outer edge of the tubular furnace, and then opening two lead grooves of the positive lead outlet-positive lead interface and the negative lead outlet-negative lead interface on the outer periphery of the blank respectively;

[0061] S8 resistance wire installation: first fold the lead wire of the resistance wire 2 according to the size and angle of the lead wire slot, then pre-brush the high-temperature adhesive evenly in each resistance wire slot 11, then insert the resistance wire 2 into the resistance wire slot 11 one by one, and press the lead wire into the lead wire slot. The high-temperature adhesive used has a high temperature resistance of not less than 1400℃;

[0062] S9: Filling and repairing the lead groove: Use a filler with a high temperature resistance of not less than 1500°C to fill and repair the lead groove of the resistance wire 2. There are many types of fillers, and the temperature resistance level meets the requirements of the present invention. Environmental protection and suitable price can be considered without limitation;

[0063] S10: Drying: placing the tubular furnace body 1 with the resistor wire 2 installed in a drying furnace for drying, and cooling after drying;

[0064] S11: furnace processing: processing the two ends and the surface of the dried tubular furnace body 1 to make its size meet the requirements;

[0065] S12 surface coating treatment: coating the surface of the tubular furnace body 1 with paint;

[0066] S13 detection: test the weight and size of the tubular furnace body 1, and connect the power supply to detect whether the resistance wire 2 is conductive and short-circuited.

[0067] The performance of the product of the present invention is described below with examples and comparative examples:

[0068] It should be noted that the present invention adopts long-fiber inorganic refractory fiber blocks or fiber blankets as raw materials because the inorganic refractory fiber blocks or fiber blankets have long fiber structures and the preparation process includes a needling step. The needling process can make the long fibers inside interweave with each other, and the long fiber interweaving structure has very good stress resistance. The present invention mainly utilizes the strong stress resistance of the long fiber interweaving structure to enhance the strength of the furnace core and the stability of the overlap between the furnace core and the resistance wire. As long as the selected inorganic refractory fiber blocks meet the requirements of bulk density of 130-240K or the fiber blanket meets the requirements of bulk density of 128-180K, the purpose of the present invention can be achieved. Therefore, the parameters of the preparation process of the inorganic refractory fiber blocks or fiber blankets are not specially limited.

[0069] Moreover, in the preparation process of the present invention, the purpose of dipping is to shape the long fiber interwoven structure in the tubular furnace body 1 by absorbing silica sol, and the addition ratio of silica sol to water will not have much effect on the stability of its shaping, and the purpose of drying is to dry the absorbed silica sol and shape the long fiber interwoven structure in the tubular furnace body 1. As long as the silica sol can be dried, the drying temperature and time have little effect. Considering cost and efficiency, the present invention preferably 120-180° C., 3-10 hours of drying, in the following embodiments, 150° C., 6 hours of drying;

[0070] The purpose of calcination is to solidify and form. Under the condition of 650°C, after calcination for 1 hour, the production conditions can be met. Under the condition of 1200°C, the upper limit of calcination is 3 hours. Exceeding the conditions will have an adverse effect on the structure and performance of the tubular furnace, and even aging will occur. The present invention mainly utilizes the long fiber interwoven structure. As long as the calcination and forming process does not destroy the internal structure of the tubular furnace body 1, the purpose of the present invention can be achieved. Therefore, there is no need to make special restrictions on the calcination temperature and time. In the following embodiments, calcination and forming are carried out at 800°C and 2 hours.

[0071] Example 1

[0072] According to the preparation process of the present invention, a bulk block of inorganic refractory fiber with a bulk density of 130K is used as a raw material for preparing the tubular furnace body 1, and the tubular furnace with a long fiber interwoven structure of the present invention is prepared as the product of Example 1;

[0073] Specifications and dimensions are as follows:

[0074] Tubular furnace body 1 dimensions: height 660mm, outer diameter 628mm, wall thickness 55mm;

[0075] The number of resistance wire slots is 40;

[0076] Resistance wire slot dimensions: length 620mm, width 15mm, depth 28mm;

[0077] Resistance wire specification: φ3.2mm / 9Ω.

[0078] Example 2

[0079] An inorganic refractory fiber block with a bulk density of 160K is used as the raw material for preparing the tubular furnace body 1, and the long fiber interwoven structure tubular furnace of the present invention is prepared as the product of Example 2. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0080] Example 3

[0081] An inorganic refractory fiber block with a bulk density of 190K is used as the raw material for preparing the tubular furnace body 1, and a tubular furnace with a long fiber interwoven structure of the present invention is prepared as the product of Example 3. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0082] Example 4

[0083] An inorganic refractory fiber block with a bulk density of 240K is used as the raw material for preparing the tubular furnace body 1, and the long fiber interwoven structure tubular furnace of the present invention is prepared as the product of Example 4. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0084] Example 5

[0085] A fiber blanket block with a bulk density of 128K is used as the raw material for preparing the tubular furnace body 1. The tubular furnace with a long fiber interwoven structure of the present invention is prepared as the product of Example 5. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0086] Example 6

[0087] A fiber blanket block with a bulk density of 150K is used as the raw material for preparing the tubular furnace body 1. The tubular furnace with a long fiber interwoven structure of the present invention is prepared as the product of Example 6. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0088] Example 7

[0089] A fiber blanket block with a bulk density of 180K is used as the raw material for preparing the tubular furnace body 1. The tubular furnace with a long fiber interwoven structure of the present invention is prepared as the product of Example 7. The preparation process, product specifications and dimensions are the same as those of Example 1.

[0090] Comparative Example 1

[0091] A tubular furnace product having the same specifications and dimensions as those in Example 1 is prepared by a vacuum forming process, the steps being:

[0092] 1) Slurry preparation: Add 1480 grade chopped refractory fiber cotton into water, disperse it, and then add a certain amount of binder to prepare a 1% concentration slurry;

[0093] 2) Mold preparation: install the resistance wire on the mold position;

[0094] 3) Molding: Immerse the mold into the prepared slurry for vacuum filtration molding. When the thickness of the tube billet reaches more than 60mm, remove the mold from the slurry pool;

[0095] 4) Demolding: Separate the formed tube from the mold;

[0096] 5) Drying: The tube is dried at 180°C;

[0097] 6) Processing: Process the outer diameter of the tube and both ends;

[0098] 7) Calcination: The processed product was calcined at 1000° C. for 1 h to prepare the product of Comparative Example 1.

[0099] Comparative Example 2

[0100] A tubular furnace product having the same specifications and dimensions as Example 1 is prepared by the same process as in Comparative Example 1, the difference from Comparative Example 1 being that the refractory grade of the chopped refractory fiber cotton is 1500 (1480 fiber and polycrystalline fiber cotton are mixed in a certain proportion).

[0101] The products of Examples 1 to 7 and the two comparative examples were tested and compared with respect to various parameters such as density, cost, stability, etc., as shown in the following table:

[0102]

[0103] From the above comparison, it can be seen that the products of Examples 1-7 prepared by the preparation process of the present invention are still very stable after being subjected to the working condition of 1100°C*72h. There is no damage in the drop test at a height of 200mm, and the overall structure can still remain intact. Under the working condition of 1100°C*72h, there is no cracking of the inner wall of the furnace, and the resistance wire is not loose.

[0104] The products of Comparative Examples 1 and 2 prepared by the vacuum forming process were damaged after being subjected to a drop test at a height of 200 mm at a temperature of 1100°C for 72 hours, indicating that their overall stability was inferior to that of the present invention. Moreover, under the temperature of 1100°C for 72 hours, the inner wall of the furnace had cracks to varying degrees, and the resistance wires also had looseness to varying degrees. Comparative Example 2 used raw materials with a higher high temperature resistance level, making its various performances significantly better than Comparative Example 1, but at the same time, the cost of a single piece of Comparative Example 2 was much higher than that of Comparative Example 1.

[0105] In summary, the tubular furnace prepared by the present invention has simple process, low cost and excellent performance, especially in terms of strong overall stress resistance. The long fiber interlaced structure is firmly overlapped with the resistance wire, so that the resistance wire will not loosen or fall off easily.

[0106] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A preparation process for a long fiber interwoven structure tubular furnace, wherein the long fiber interwoven structure tubular furnace comprises a tubular furnace body and a plurality of resistance wires arranged inside the tubular furnace, wherein the inner wall of the tubular furnace body is provided with a plurality of resistance wire grooves for installing the resistance wires, wherein: The preparation of the long fiber interwoven structure tubular furnace comprises the following steps: S1 material preparation: select inorganic refractory fiber blocks with a bulk density of 130-240K and a long fiber interwoven structure or fiber blanket blocks with a bulk density of 128-180K as raw materials for preparing the tubular furnace body; S2 cutting: according to the size of the tubular furnace body to be prepared, a blank having a length corresponding to the outer perimeter of the tubular furnace body, a width corresponding to the height of the tubular furnace body, and a thickness corresponding to the wall thickness of the tubular furnace body is cut from the inorganic refractory fiber block or the fiber blanket block; S3: Opening resistance wire grooves: Lay the blank flat, then carve a number of resistance wire grooves on the top surface of the blank, cut wedges at both ends of the blank for staggered splicing, and clamp a shaping die in each resistance wire groove for limiting and protecting the resistance wire groove and the partition between two adjacent resistance wire grooves; S4 forming: according to the size of the tubular furnace body to be prepared, the corresponding tube rolling mold is selected, and the side engraved with the resistance wire groove is the inner side. The blank is rolled on the tube rolling mold so that the end is connected to the end to form the blank prototype of the tubular furnace body, and the end connection of the blank is bonded or sutured with high temperature resistant wire; S5 Hardening: Place the tube coiling mold together with the tube furnace body blank on it in a dipping tank for dipping. After dipping, take it out, evacuate it and place it in a drying oven for drying. S6 calcination: the shaping mold and the tube coiling mold are removed from the molds respectively, and then the tubular furnace body is calcined at 650-1200°C for 1-3h to form the tubular furnace body; S7: Opening lead grooves: using the ends of one group of adjacent resistance wire grooves in the tubular furnace body as the positive lead outlet and the negative lead outlet, opening the grooves to the outside of the tubular furnace, pre-setting the positive lead interface and the negative lead interface on the outer edge of the tubular furnace, and then opening two lead grooves of the positive lead outlet-positive lead interface and the negative lead outlet-negative lead interface on the outer periphery of the blank respectively; Installation of S8 resistor wire: first fold the resistor wire lead wire according to the size and angle of the lead wire slot, then pre-brush high-temperature adhesive evenly in each resistor wire slot, then insert the resistor wires into the resistor wire slots one by one, and press the positive and negative lead wires into the corresponding lead wire slots respectively; S9 lead slot filling and repair: Use filler with temperature resistance not less than 1500℃ to fill and repair the resistance wire lead slot; S10: Drying: placing the furnace body in a drying furnace for drying, and cooling after drying; S11: Furnace processing: Process the two ends and surface of the dried tubular furnace body to make its size meet the requirements; S12 Surface coating treatment: Use paint to coat the surface of the tubular furnace body; S13 test: Test the weight and size of the tubular furnace body, and connect the power supply to check whether the resistance wire is conductive or short-circuited.

2. The preparation process of the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: The steps for preparing the inorganic refractory fiber block include: Step 1: Weigh the raw materials by weight: 33-48 parts of aluminum oxide, 45-60 parts of silicon dioxide, and 0.1-1 parts of additives, wherein the additives are composed of coconut oil diethanolamide and silica sol, with coconut oil diethanolamide accounting for 85-95% and silica sol accounting for 15-5%, and mix and melt the raw materials according to the proportion; Step 2: Spinning the molten raw material into fibers, and spraying additives on the fibers in a spraying manner through a material adding device during spinning; Step 3: The fibers are collected and needle punched to form bulk fibers.

3. The preparation process of the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: The shaping mold is a strip structure, and L-shaped ears for limiting the position against the inner wall of the tubular furnace body are symmetrically arranged on both sides of its top surface. The shaping mold is inserted into the resistance wire groove with the bottom surface facing inward and the top surface facing outward.

4. The process for preparing the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: The tube rolling mould has a vacuum box tubular structure, and a plurality of through holes are evenly opened on the side wall thereof.

5. The process for preparing the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: In step S4 and step S8, the high temperature bonding of the blanks which are connected end to end and the resistance wire slots which are pre-brushed is resistant to high temperatures of not less than 1400°C.

6. The process for preparing the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: The dipping process in step S5 uses silica sol, and the addition ratio of silica sol to water is 6:4, or 7:3, or 8:2, or 9:1 or original glue.

7. The process for preparing the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: In step S5, the dipping time is 5 to 30 seconds, the drying temperature after vacuuming is 120 to 180° C., and the drying time is 3 to 10 hours.

8. The process for preparing the long fiber interwoven structure tubular furnace according to claim 1, characterized in that: Both ends of the partition between each two adjacent resistance wire slots are also provided with wire slots for clamping with the two adjacent groups of resistance wire connecting sections.

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