A box-type resistance furnace structure

Abstract

This invention relates to the field of resistance furnace technology, and particularly to a box-type resistance furnace structure; it includes a furnace shell, a controller, an insulation layer, and a furnace door; a through hole is provided in the middle of the front wall of the insulation layer, and an insulation block is detachably and sealed inside the through hole; a furnace chamber is detachably installed inside the insulation layer; this invention uses four L-shaped modules stacked and limited in sequence to form a detachable furnace chamber, and integrates a pushing part and an energizing part on the insulation block, so that when the furnace chamber is damaged by explosion or other reasons, only the damaged L-shaped module needs to be replaced without disassembling the furnace shell and insulation layer. At the same time, by using the linkage between the installation of the insulation block and the pushing process of the L-shaped module, the heating element is automatically pressed and fixed and the circuit is connected, which solves the problems of existing integral furnace chambers needing to be scrapped as a whole after explosion, requiring many disassembly parts, and taking a long time to repair.

Description

Technical Field

[0001] This invention relates to the field of resistance furnace technology, and in particular to a box-type resistance furnace structure. Background Technology

[0002] A box-type resistance furnace, also known as a muffle furnace, is a common type of resistance heating equipment. It converts electrical energy into heat energy by generating Joule heat through the passage of electric current through a resistive material, thus heating the workpiece or material. Depending on the operating temperature, box-type resistance furnaces use resistance wire, silicon carbide rods, or silicon molybdenum rods as heating elements. Box-type resistance furnaces are widely used in production and experimentation in fields such as ceramics, metallurgy, electronics, glass, chemicals, machinery, refractory materials, and new material development.

[0003] The box-type resistance furnace is mainly composed of a furnace shell, insulation layer, furnace chamber, heating element, temperature measuring element and controller. The furnace chamber adopts an integral structure, which is made of high alumina refractory material by integral casting or integral sintering, forming an inseparable integral cavity.

[0004] However, the following problems exist in the current use of the furnace: Because the furnace adopts an integral casting or sintering structure, when the furnace cracks, peels off, or even bursts due to rapid heating and cooling, erosion by molten material, or sudden pressure rise caused by material volatilization, even if only a side wall or a certain area is damaged, it is impossible to replace the damaged part alone. The entire furnace must be scrapped and replaced as a whole. In addition, during long-term use, slag, hard deposits, or oil and carbon deposits will accumulate on the inner wall of the furnace. The heating elements will also need to be replaced due to surface oxidation or local breakage. These situations also require the furnace to be disassembled for cleaning and maintenance. Since the furnace is completely wrapped by the insulation layer and the furnace shell, and the heating elements are embedded in the furnace wall, the operator must remove the furnace shell, insulation layer, heating elements, and electrical wiring from the outside to the inside in order to remove the damaged furnace and replace it with a new furnace. This process requires the disassembly of a large number of bolts and parts, making the maintenance operation cumbersome and time-consuming.

[0005] Therefore, the problems of needing to scrap the entire integral furnace after partial damage, the cumbersome cleaning, maintenance and replacement operations, the large number of disassembled parts and the long repair time are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the above problems, the present invention provides a box-type resistance furnace structure to solve the aforementioned technical problems.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a box-type resistance furnace structure, including a furnace shell, a controller, a heat insulation layer and a furnace door; a through hole is provided in the middle of the front wall of the heat insulation layer, and a heat insulation block is detachably and sealed in the through hole, and a furnace chamber is detachably installed in the heat insulation layer.

[0008] As a preferred embodiment, the furnace chamber is composed of four L-shaped modules stacked and positioned in sequence to form a whole. The front wall of each of the four L-shaped modules is triangular, and the four triangles are joined together to form a complete square front wall. A heating element is detachably installed on each L-shaped module.

[0009] As a preferred embodiment, the L-shaped module is evenly provided with circular grooves, the heating element is installed in the circular grooves, the inner wall of the furnace is provided with rectangular holes corresponding to the circular grooves, the rectangular holes are connected to the circular grooves, the other end of the heating element is inserted into a limiting plate, two clamping blocks are slidably installed on the limiting plate, and electrode plates are fixedly installed on the opposite sides of the two clamping blocks. The heat preservation block is provided with an energizing part and a pushing part.

[0010] As a preferred embodiment, during the process of pushing the L-shaped module into place along the inner wall of the insulation layer, it will come into contact with the pushing part. The pushing part drives the clamping block to slide towards each other, so that the electrode plate presses the end of the heating element from both sides. At the same time, the energized part on the insulation block contacts the electrode plate, forming a power supply circuit from the energized part and the electrode plate to the heating element.

[0011] As a preferred embodiment, the pushing part includes a fixing plate, and a fixing plate corresponding to the L-shaped module is fixedly installed on the heat insulation block. A pushing block is provided between two adjacent heating elements. The pushing block has a right-angled trapezoidal structure with the inclined surface facing down. The pushing block is fixedly installed on the corresponding fixing plate. The clamping block has inclined grooves that cooperate with the inclined surface of the pushing block and correspond to it one by one.

[0012] As a preferred embodiment, the energized part includes a conductive plate, and a conductive plate is disposed between two adjacent electrode plates located on the inner side. The conductive plate is fixedly installed on the insulation block, and an electrode post is fixedly installed on one of the pair of conductive plates, the electrode post penetrating the insulation block and the furnace shell.

[0013] As a preferred option, ceramic fiber paper is filled between two adjacent L-shaped modules, and the ceramic fiber paper is not exposed on the inner surface of the furnace.

[0014] As a preferred embodiment, a limiting post is coaxially fixedly installed on the circular groove, and the limiting post is plugged into the heating element.

[0015] As a preferred option, the bottom L-shaped module is fixed to the insulation layer with ceramic bolts.

[0016] As a preferred embodiment, the insulation block is fixedly installed on the insulation layer using studs.

[0017] As a preferred embodiment, the conductive plate is made of Cr20Ni80 or silicon-carbon composite material.

[0018] As a preferred embodiment, the heating element is a double-threaded silicon carbide tube.

[0019] The above-mentioned one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: First, the present invention uses four L-shaped modules to be stacked and limited in sequence to form a detachable furnace chamber, and integrates a pushing part and an electrical part on the insulation block. When the furnace chamber is damaged by explosion or other reasons, only the damaged L-shaped module needs to be replaced without disassembling the furnace shell and insulation layer. At the same time, by using the linkage between the installation of the insulation block and the pushing process of the L-shaped module, the pressing and fixing of the heating element and the circuit conduction are automatically completed, which solves the problems of existing integral furnace chambers needing to be scrapped as a whole after explosion, having many disassembled parts, and having long maintenance time.

[0020] Second, the furnace chamber of this invention is assembled by stacking and limiting four independent L-shaped modules in sequence. Only the bottom L-shaped module is fixed to the insulation layer by ceramic bolts. The other L-shaped modules are positioned by stacking and pressing each other. When an L-shaped module cracks or is damaged due to a furnace explosion, the ceramic bolts can be removed and the modules can be pulled out in reverse order of stacking. The damaged module can be replaced and then reassembled. There is no need to scrap the entire furnace chamber or disassemble the furnace shell and insulation layer, thereby reducing maintenance costs.

[0021] Third, this invention utilizes the cooperation between the pushing part on the insulation block and the clamping block. During the installation of the L-shaped module by pushing it in along the inner wall of the insulation layer, the pushing part drives the two clamping blocks to move towards each other, so that the electrode plate on the clamping block automatically presses against the end of the heating element. At the same time, the energized part on the insulation block contacts the electrode plate to form a power supply circuit. When the L-shaped module is pulled out, the pushing part disengages from the clamping block, the clamping block is released, the electrode plate separates from the heating element, and the circuit is automatically cut off. The above process does not require separate wiring, welding, or desoldering, realizing rapid connection and disconnection of electrical connections, further shortening maintenance downtime.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the furnace chamber after assembly and fixation to the insulation layer according to the present invention;

[0026] Figure 3This is a schematic diagram of the structure of the insulation block fixed on the insulation layer according to the present invention;

[0027] Figure 4 This is a schematic diagram of the structure between the insulation block and the furnace chamber of the present invention;

[0028] Figure 5 This is an exploded view of the furnace structure of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure between the heating element and the limiting post of the present invention;

[0030] Figure 7 This is a schematic diagram of the structure of the energized part of the present invention;

[0031] Figure 8 This is a schematic diagram of the clamping block of the present invention;

[0032] Figure 9 This is an exploded view of the clamping block and electrode plate of the present invention;

[0033] Figure 10 This is a partial structural diagram of the pushing part of the present invention.

[0034] Reference numerals: 10, furnace shell; 11, controller; 12, insulation layer; 120, insulation block; 121, stud; 13, furnace door; 2, L-shaped module; 20, ceramic bolt; 21, ceramic fiber paper; 22, limiting post; 14, heating element; 3, limiting plate; 4, clamping block; 5, electrode plate; 6, energized part; 60, conductive plate; 61, electrode post; 7, pushing part; 70, fixing plate; 71, pushing block; 72, inclined groove. Detailed Implementation

[0035] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a box-type resistance furnace structure includes a furnace shell 10, a controller 11, a heat insulation layer 12, and a furnace door 13; a through hole is provided in the middle of the front wall of the heat insulation layer 12, and a heat insulation block 120 is detachably and sealed in the through hole; a furnace chamber is detachably installed inside the heat insulation layer 12.

[0037] like Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, the furnace chamber is composed of four L-shaped modules 2 stacked and positioned in sequence to form a whole. The front wall of each of the four L-shaped modules 2 is triangular, and the four triangles are joined together to form a complete square front wall. A heating element 14 is detachably installed on each L-shaped module 2.

[0038] like Figure 3 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the L-shaped module 2 has evenly spaced circular grooves, and the heating element 14 is installed in the circular grooves. The inner wall of the furnace has rectangular holes that correspond one-to-one with the circular grooves. The rectangular holes are connected to the circular grooves. The other end of the heating element 14 is inserted into a limiting plate 3. Two clamping blocks 4 are slidably installed on the limiting plate 3. Electrode plates 5 are fixedly installed on the opposite sides of the two clamping blocks 4. The heat preservation block 120 is provided with an energizing part 6 and a pushing part 7.

[0039] like Figure 2 As shown, the bottom L-shaped module 2 is fixed to the insulation layer 12 by ceramic bolts 20.

[0040] like Figure 5 , Figure 7 and Figure 8 As shown, ceramic fiber paper 21 is filled between two adjacent L-shaped modules 2, and the ceramic fiber paper 21 is not exposed on the inner surface of the furnace.

[0041] like Figure 3 As shown, the insulation block 120 is fixedly installed on the insulation layer 12 by studs 121.

[0042] like Figures 1 to 9 As shown, in specific operation, firstly, before the insulation layer 12 is installed on the front furnace shell 10, the heating element 14 is pre-installed. Take any one of the four L-shaped modules 2, and use the limiting post 22, which is coaxially fixed on the inner wall of the evenly opened circular groove on it, as the positioning reference. Insert the end of the heating element 14 into the circular groove, so that the limiting post 22 is embedded in the hole at the end of the heating element 14, thus completing the positioning of the heating element 14 on the L-shaped module 2. After all the heating elements 14 on the same L-shaped module 2 are positioned, put a limiting plate 3 on the other end of all the heating elements 14 on the same L-shaped module 2, so that the heating element 14 passes through the limiting plate 3 and extends out to an appropriate length. Two clamping blocks 4 are pre-slidably installed on the limiting plate 3. In the initial state, the clamping blocks 4 are in the open position. Repeat the above operation for the four L-shaped modules 2 in sequence, so that each L-shaped module 2 is independently installed with the heating element 14, the limiting plate 3, the clamping blocks 4, and the electrode plate 5.

[0043] Then, the components on the insulation block 120 are installed. The shape of the insulation block 120 matches the through hole opened in the middle of the front wall of the insulation layer 12. The pushing part 7 and the energizing part 6 are pre-fixed on the rear end face of the insulation block 120. The pushing part 7 is used to push the clamping block 4 later. The energizing part 6 is used to conduct electricity with the electrode plate 5. The insulation block 120 is inserted into the through hole from the front side of the insulation layer 12 and fixed on the insulation layer 12 by the stud 121 to ensure a seal. Since the stud 121 is located in the low-temperature zone outside the insulation layer 12, there is no need to use expensive high-temperature resistant ceramic materials. Ordinary stainless steel stud 121 can meet the requirements of strength, sealing and repeated disassembly and assembly. At this time, the insulation block 120 is fixed, but its pushing part 7 faces the inside of the furnace, waiting to cooperate with the clamping block 4 to be installed later. At this time, the pushing part 7 on the insulation block 120 has not yet contacted the clamping block 4 because the L-shaped module 2 has not yet been installed.

[0044] Next, install the front furnace shell 10 and fix it to the front edge of the insulation layer 12 to form a complete front structure of the furnace body. The middle of the front furnace shell 10 has a thermocouple mounting port, which penetrates the insulation block 120 and the furnace chamber.

[0045] Finally, install the four L-shaped modules 2 in sequence, from left to right and bottom. Push each L-shaped module 2 into the insulation layer 12 from the opening of the furnace door 13 along the inner wall of the insulation layer 12. First, install the left L-shaped module 2 and push it into the predetermined position. Then, install the upper L-shaped module 2, so that its left edge overlaps the upper surface of the left L-shaped module 2. Next, install the right L-shaped module 2, so that its upper edge overlaps the right edge of the upper L-shaped module 2. Finally, install the lower L-shaped module 2, so that its left and right edges overlap the side edges of the left and right L-shaped modules 2 respectively, and fix the lower L-shaped module 2 to the insulation layer 12 with ceramic bolts 20. When the last L-shaped module 2 is installed... When in place and locked, all L-shaped modules 2 are stacked and locked in sequence to form an integral furnace. At this time, since the insulation block 120 has been pre-fixed, its pushing part 7 is just outside the two clamping blocks 4 on the limiting plate 3. As the L-shaped module 2 is pushed in, the pushing part 7 gradually contacts the clamping block 4 and applies a pushing force, forcing the two clamping blocks 4 to slide towards each other along the limiting plate 3, so that the electrode plate 5 on the clamping block 4 is tightly attached to the wiring terminal at the end of the heating element 14. At the same time, the energized part 6 on the insulation block 120 contacts the electrode plate 5 to form a complete power supply circuit. The installation sequence of the L-shaped modules 2 ensures the final engagement time of the pushing part 7 and the clamping block 4, avoiding interference caused by premature contact.

[0046] Before use, close the furnace door 13. The inner wall of the furnace door 13 contacts the rear wall of the furnace and applies a slight pre-tightening force to further stabilize the furnace. After power is applied, the current generates heat through the power supply part 6, the electrode plate 5, and the heating element 14. The joint between adjacent L-shaped modules 2 is filled with ceramic fiber paper 21, and the ceramic fiber paper 21 is completely hidden inside the joint and not exposed on the inner surface of the furnace, thus ensuring the temperature uniformity of the inner wall of the furnace at high temperatures.

[0047] When a module in the furnace is damaged due to a furnace explosion, the maintenance procedure is as follows: Open the furnace door 13, loosen the ceramic bolts 20 of the lower L-shaped module 2, and pull out the lower, right, upper, and left modules in reverse order of installation. Since the insulation block 120 is pre-fixed, the pushing part 7 automatically disengages from the clamping block 4 when the module is pulled out. The clamping block 4 is released, and the electrode plate 5 separates from the heating element 14 without clamping force. Only the damaged L-shaped module 2 needs to be replaced. Other L-shaped modules 2 do not need to be replaced. Reinstall the modules in the order of left, upper, right, and lower. During the pushing process, the pushing part 7 of the insulation block 120 pushes the clamping block 4 again to make the electrode plate 5 fit. Finally, tighten the ceramic bolts 20 and close the furnace door 13 to restore use. When cleaning the inner wall of the furnace or replacing the heating element 14, the same disassembly procedure is followed. There is no need to disassemble the insulation block 120, the front furnace shell 10, and other undamaged modules, which significantly simplifies the maintenance operation.

[0048] The above embodiments demonstrate the assembly steps, working process, and maintenance and replacement effects of the present invention. All operations do not require disassembling the furnace shell 10, the insulation layer 12, and external wiring, thus achieving the goal of modular and rapid replacement after a furnace explosion.

[0049] like Figure 3 , Figure 7 , Figure 9 and Figure 10 As shown, the energized part 6 includes a conductive plate 60. A conductive plate 60 is disposed between two adjacent electrode plates 5 located on the inner side. The conductive plate 60 is fixedly installed on the heat insulation block 120. An electrode post 61 is fixedly installed on a pair of conductive plates 60. The electrode post 61 penetrates the heat insulation block 120 and the furnace shell 10.

[0050] like Figure 7 , Figure 8 and Figure 10 As shown, the pushing part 7 includes a fixing plate 70. The insulation block 120 is fixedly installed with a fixing plate 70 corresponding to the L-shaped module 2. A pushing block 71 is provided between two adjacent heating elements 14. The pushing block 71 has a right-angled trapezoidal structure with the inclined surface facing down. The pushing block 71 is fixedly installed on the corresponding fixing plate 70. The clamping block 4 has a sloping groove 72 that matches the inclined surface of the pushing block 71 and corresponds to it.

[0051] like Figure 6As shown, a limiting post 22 is coaxially fixedly installed on the circular groove, and the limiting post 22 is plugged into the heating element 14.

[0052] like Figure 7 and Figure 10 As shown, the conductive plate 60 is made of Cr20Ni80 or silicon-carbon composite material.

[0053] like Figure 6 As shown, the heating element 14 is a double-threaded silicon carbide tube.

[0054] like Figure 3 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, during actual operation, when the insulation block 120 is installed, the fixing plate 70 on it moves into the furnace along with the insulation block 120. The pushing block 71 on the fixing plate 70 (which can be made of high-temperature resistant insulating materials such as silicon carbide or silicon nitride to ensure that it does not deform or conduct electricity at high temperatures) is directly aligned with the inclined groove 72 opened on the clamping block 4 (also made of silicon carbide) that is slidably installed on the limiting plate 3. When the insulation block 120 is pushed in, the inclined groove 72 abuts against the inclined surface of the pushing block 71 to push the two clamping blocks in the furnace. The holding block 4 slides along the limiting plate 3 towards each other, so that the electrode plate 5 on the holding block 4 presses the end of the heating element 14. The heating element 14 adopts a double-threaded silicon carbide tube, which has the following advantages: the straight rod structure of equal diameter can realize single-sided wiring, so that all electrical connections are concentrated on one side of the insulation block 120, avoiding opening holes on both sides of the furnace body, and facilitating modular disassembly and assembly; at the same time, the tube wall is thicker, the heating is uniform, the oxidation resistance is strong, the life is long at high temperature, and the deformation is small, which is highly consistent with the compact design of the quick-change furnace chamber of this invention.

[0055] As the clamping block 4 slides, the conductive plate 60 (Cr20Ni80 or silicon-carbon composite material, characterized by high temperature resistance, oxidation resistance, and stable conductivity) fixed on the insulation block 120 gradually comes into contact with the inner surfaces of the electrode plates 5 on the two clamping blocks 4. One pair of conductive plates 60 has an electrode post 61 fixed on it, which extends through the insulation block 120 and the furnace shell 10. Thus, current flows from the external power source through the electrode post 61, the conductive plate 60, and the electrode plate 5 to the heating element 14, forming a complete circuit. The conductive plate 60 and the electrode plate 5 have surface contact, resulting in low and stable contact resistance.

[0056] During disassembly, the insulation block 120 is pulled out in the reverse direction, the inclined surface is disengaged from the inclined groove 72, the clamping block 4 is released, and the electrode plate 5 no longer presses against the heating element 14.

[0057] The bottom L-shaped module 2 is fixed to the insulation layer 12 by ceramic bolts 20. The ceramic bolts 20 were chosen based on the following considerations: metal bolts will oxidize and creep at high temperatures, and their coefficient of thermal expansion differs greatly from that of the L-shaped module 2, which can easily lead to loose connections or cracking of the L-shaped module 2; while ceramic bolts 20 are resistant to high temperatures and oxidation, and are non-conductive, avoiding the risk of short circuits. They can also be repeatedly disassembled and reassembled to meet the needs of modular replacement.

[0058] The ceramic fiber paper 21 filling the space between adjacent L-shaped modules 2 is compressed and hidden inside the overlap seam, and is not exposed on the inner surface of the furnace. The ceramic fiber paper 21 absorbs thermal expansion and seals the gaps. At the same time, because it is not exposed, it does not form a cold zone, thus ensuring the uniformity of the temperature of the inner wall of the furnace.

[0059] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0060] Furthermore, the terms "first," "second," "number one," and "number two" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," "number one," or "number two" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A box-type resistance furnace structure, comprising a furnace shell, a controller, an insulation layer, and a furnace door; characterized in that: A through hole is provided in the middle of the front wall of the insulation layer, and an insulation block is detachably and sealed in the through hole. A furnace is detachably installed in the insulation layer. The furnace chamber is composed of four L-shaped modules stacked and positioned in sequence to form a whole. The front wall of each of the four L-shaped modules is triangular, and the four triangles are joined together to form a complete square front wall. Each L-shaped module is detachably equipped with a heating element. The L-shaped module has evenly spaced circular grooves, and the heating element is installed in the circular groove. The inner wall of the furnace has rectangular holes that correspond one-to-one with the circular grooves. The rectangular holes are connected to the circular grooves. The other end of the heating element is inserted into a limiting plate. Two clamping blocks are slidably installed on the limiting plate. Electrode plates are fixedly installed on the opposite sides of the two clamping blocks. The heat preservation block is provided with an energizing part and a pushing part. The pushing part includes a fixing plate. The insulation block is fixedly installed with a fixing plate that corresponds one-to-one with the L-shaped module. A pushing block is provided between two adjacent heating elements. The pushing block has a right-angled trapezoidal structure with the inclined surface facing down. The pushing block is fixedly installed on the corresponding fixing plate. The clamping block has inclined grooves that cooperate with the inclined surface of the pushing block and correspond one-to-one. As the L-shaped modules are pushed into place along the inner wall of the insulation layer, they will come into contact with the pushing part. The pushing part drives the clamping block to slide towards each other, so that the electrode plate presses the end of the heating element from both sides. At the same time, the energized part on the insulation block contacts the electrode plate, forming a power supply circuit from the energized part and the electrode plate to the heating element.

2. The box-type resistance furnace structure according to claim 1, characterized in that: The energized part includes a conductive plate, and a conductive plate is provided between two adjacent electrode plates located on the inner side. The conductive plate is fixedly installed on the insulation block, and an electrode post is fixedly installed on one of the pair of conductive plates. The electrode post penetrates the insulation block and the furnace shell.

3. The box-type resistance furnace structure according to claim 1, characterized in that: The space between two adjacent L-shaped modules is filled with ceramic fiber paper, and the ceramic fiber paper is not exposed on the inner surface of the furnace.

4. The box-type resistance furnace structure according to claim 1, characterized in that: A limiting post is coaxially fixedly installed on the circular groove, and the limiting post is plugged into the heating element.

5. The box-type resistance furnace structure according to claim 1, characterized in that: The bottom L-shaped module is fixed to the insulation layer with ceramic bolts.

6. The box-type resistance furnace structure according to claim 1, characterized in that: The insulation block is fixedly installed on the insulation layer by studs.

7. The box-type resistance furnace structure according to claim 2, characterized in that: The conductive plate is made of Cr20Ni80 or silicon-carbon composite material.

8. The box-type resistance furnace structure according to claim 1, characterized in that: The heating element is a double-threaded silicon carbide tube.

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