Lining structure for a box-type resistance furnace

Abstract

The utility model discloses a furnace lining structure of box type resistance furnace relates to heating equipment field, including refractory layer and mounting frame, and the furnace hearth of rectangular front side opening is enclosed by refractory layer, and the inner wall of furnace hearth is treated by fine grinding, the mounting frame is silicon carbide reinforced ceramic matrix composite material quality, and the gap of thermal expansion is left to the adaptation and placement in the inner peripheral surface of furnace hearth, and the mounting frame includes two back type fixed frame and the zirconium oxide toughened corundum barrier installation board of connection, and the resistance wire is arranged the winding through -hole of barrier installation board and is tensioned between the fixed frame, and keeps the gap with refractory layer. This structure solves the problem that refractory layer is easy to crack and is difficult to maintain caused by traditional " refractory layer grooving and embedding wire", and prolongs the service life of furnace lining.

Description

Technical Field

[0001] This utility model relates to the field of box-type resistance furnaces, and in particular to a furnace lining structure for a box-type resistance furnace. Background Technology

[0002] The furnace lining of a box-type resistance furnace includes a refractory layer, an insulation layer, and an outermost protective layer. Resistance wires are installed on the inner wall of the refractory layer, i.e., inside the furnace chamber. Currently, the mainstream structure for the refractory layer and resistance wires is "refractory layer + slotted wire embedding". The refractory layer is mostly integrally cast or spliced. To fix the resistance wires, a semi-open groove needs to be processed on the inner wall of the refractory layer, and then the resistance wires are embedded in the grooves. The displacement is restricted by the side wall of the grooves, while the refractory layer is used to achieve heat insulation.

[0003] This traditional structure has several drawbacks in practical applications: First, the slotting disrupts the overall continuity of the refractory layer. Under high-temperature conditions, the edges of the tank are prone to cracking due to concentrated thermal stress. The expansion of these cracks can lead to the peeling off of the refractory layer, which not only shortens the furnace lining life but also increases heat loss due to damage to the insulation structure. Second, the resistance wire is tightly attached to the tank, making maintenance difficult. When the resistance wire needs to be replaced due to high-temperature aging or breakage, the workpiece and insulation layer inside the furnace must be removed first. If the tank deforms due to cracks, the refractory layer must be partially removed, significantly extending the equipment downtime. Third, the tank easily accumulates impurities such as oxide scale and dust generated by the heating of the workpiece. These impurities can not only cause poor contact between the resistance wire and the tank, leading to local overheating and short circuits, but may also cause the resistance wire to fall out of the tank when it is damaged, as the resistance wire loses its effective constraint. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a furnace lining structure for a box-type resistance furnace. The core solution is to address the issue that in the existing "refractory layer + slotted wire embedding" structure, the slotting of the inner wall of the refractory layer damages its structural integrity, leading to easy cracking and peeling of the refractory layer under high-temperature conditions and a short furnace lining life.

[0005] The technical solution of this utility model is as follows: A furnace lining structure for a box-type resistance furnace includes a refractory layer that encloses a rectangular furnace chamber with a front opening. The inner wall of the furnace chamber is precision ground to prevent local bulges that could lead to stress concentration at high temperatures. An installation frame is fitted onto the inner circumferential surface of the furnace chamber. The installation frame is made of silicon carbide reinforced ceramic matrix composite material (SiC / CMC). There is a fitting gap between the outer contour of the installation frame and the inner circumferential surface of the furnace chamber to accommodate the thermal expansion of various components at ultra-high temperatures and to allow sufficient clearance to prevent jamming. The mounting frame includes two U-shaped fixing brackets, which are arranged at intervals along the front and rear longitudinal direction of the furnace and are adapted to fit the shape of the inner circumferential surface of the furnace. A barrier mounting plate assembly is connected between the opposite sides of the two U-shaped fixing frames. The barrier mounting plate assembly includes multiple barrier mounting plates that are parallel and spaced apart along the circumference of the U-shaped fixing frames. The barrier mounting plates are made of zirconia toughened corundum ceramic. Each barrier mounting plate has a winding through hole for the resistance wire to pass through. The U-shaped fixing frame located at the rear side of the furnace and the corresponding position at the rear side of the refractory layer are both provided with through holes for the end of the resistance wire to pass through. The through holes are circular light holes. The resistance wire is sequentially threaded through the winding through holes of the multiple barrier mounting plates and tensioned and fixed between the two U-shaped fixing frames, with a gap between the resistance wire and the inner circumferential surface of the fire-resistant layer.

[0006] Furthermore, the two loop-shaped fixing frames are arranged symmetrically; each loop-shaped fixing frame includes two horizontal beams spaced parallel to each other in the horizontal direction, and two vertical beams spaced parallel to each other in the vertical direction. The upper and lower end faces of the longitudinal beam are provided with T-shaped snap-fit ​​platforms. The snap-fit ​​platforms and the longitudinal beam are integrally formed. The snap-fit ​​platforms extend along the front and rear longitudinal direction of the furnace, and their extension length is shorter than the length of the longitudinal beam. The snap-fit ​​platforms are located on the side of the longitudinal beam end face that is away from the barrier mounting plate group. Each crossbeam is provided with a blind groove adapted to the snap-fit ​​platform. After the longitudinal beam is snapped and fixed to the blind groove of the crossbeam through the snap-fit ​​platform, Al2O3-based high-temperature ceramic adhesive is applied to the snap-fit ​​joint for reinforcement, further improving the connection stability.

[0007] Furthermore, the upper and lower end faces of the barrier mounting plate are concave arc surfaces facing each other, forming the first limiting area; multiple baffles are integrally protruding from both the left and right ends of the barrier mounting plate along the width direction of the furnace chamber, and the baffles are arranged at intervals along the front and rear depth direction of the furnace chamber, forming a double limiting structure of "concave surface + side baffle" with the arc surface. This combined structure can reduce the lateral offset after the resistance wire is inserted, effectively avoiding large-scale shaking of the resistance wire due to thermal expansion or slight vibration at ultra-high temperature.

[0008] The arc surface is provided with two winding through holes spaced apart along the longitudinal direction of the furnace chamber, and is respectively set close to two U-shaped fixing frames; the layout of the double through holes prevents the installation plate from distinguishing between the positive and negative directions when installing the U-shaped fixing frame, thus simplifying the assembly process.

[0009] Furthermore, both the front and rear ends of the barrier mounting plate are provided with cuboid connecting blocks, and the two U-shaped fixing brackets are provided with connecting holes for the connecting parts to pass through at the corresponding positions of the connecting blocks. When the connecting blocks and connecting holes are engaged, high-temperature ceramic thread adhesive is applied to prevent loosening.

[0010] Furthermore, there are multiple through holes, which are spaced apart along the circumference of the U-shaped fixing frame. The through holes are staggered with the barrier mounting plate group, and each barrier mounting plate corresponds to one through hole to accommodate the lead-out requirements of the resistance wire at different positions.

[0011] In Example 1, a barrier mounting plate assembly is connected between the opposite sides of the longitudinal beams of the two U-shaped fixing frames. This layout allows the resistance wires to be arranged along the left and right sides of the furnace, achieving heating on both sides of the furnace.

[0012] In Example 2, the barrier mounting plate group is connected between the opposite sides of the longitudinal beams and the opposite sides of the transverse beams of the two U-shaped fixing frames. This full circumferential layout allows the resistance wire to be arranged around the left and right sides and the top and bottom of the furnace, so as to achieve heating of the four sides of the furnace.

[0013] The beneficial effects of this utility model are as follows: 1. This utility model sets up an independent mounting frame to support the resistance wire, which is different from the traditional design of "grooving the inner wall of the refractory layer". This avoids the grooving from damaging the overall continuity of the refractory layer. The resistance wire is fixed by the mounting frame and the barrier mounting plate and does not come into direct contact with the refractory layer. This can reduce the cracks caused by thermal stress concentration in the refractory layer at high temperatures, reduce the risk of refractory layer peeling, extend the service life of the furnace lining and reduce heat loss caused by damage to the insulation structure.

[0014] 2. In this utility model, the mounting frame can be pushed and pulled along the mating gap of the inner circumference of the furnace chamber as a whole, and the resistance wire is not directly bound to the refractory layer. When the resistance wire needs maintenance and replacement, there is no need to remove the workpiece in the furnace or remove the refractory layer. The mounting frame can be pulled out from the furnace opening, which greatly shortens the equipment downtime and reduces the difficulty of maintenance operation. At the same time, it can avoid the accumulation of impurities such as oxide scale and dust in the refractory layer tank, and reduce faults such as poor contact of the resistance wire and local overheating.

[0015] 3. The barrier mounting plate of this utility model adopts a double limiting structure of "arc surface + baffle". The arc surface forms the first limiting area, and the baffle is arranged at intervals along the longitudinal direction of the furnace. The two together can restrain the lateral displacement of the resistance wire, effectively preventing the resistance wire from shaking significantly due to thermal expansion or slight vibration under ultra-high temperature, preventing the resistance wire from accidentally contacting the refractory layer, and improving the stability of equipment operation. Moreover, the double through hole layout eliminates the need to distinguish the positive and negative directions when installing the barrier mounting plate, simplifying the assembly process.

[0016] 4. This utility model provides two heating layout options: assembling the barrier mounting plate only between the longitudinal beams of the U-shaped fixed frame can achieve heating on both sides of the furnace; assembling the barrier mounting plate between both the longitudinal beams and the transverse beams can achieve heating on all four sides of the furnace, which can adapt to the heating requirements of workpieces of different shapes and sizes and improve the uniformity of temperature distribution in the furnace. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of Embodiment 1 of the present invention.

[0019] Figure 3 This is a schematic diagram of Embodiment 2 of the present invention.

[0020] Figure 4 This is a schematic diagram of the assembly of a U-shaped frame, a barrier mounting plate, and a resistance wire according to this utility model.

[0021] Figure 5 This is a schematic diagram of the disassembly of a U-shaped frame according to the present invention.

[0022] Figure 6 This is a schematic diagram of a barrier mounting plate structure according to the present invention.

[0023] Reference numerals in the attached diagram: 1. Fire-resistant layer; 2. Mounting frame; 2-1. U-shaped fixing bracket; 2-1.1. Through hole; 2-1.2. Crossbeam; 2-1.2.1. Blind groove; 2-1.3. Longitudinal beam; 2-1.3.1. Clip-on platform; 2-2. Barrier mounting plate; 2-2.1. Winding through hole; 2-2.2. Edge retaining wall; 2-2.3. Connecting block; 3. Resistance wire. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0025] like Figures 1 to 6As shown, the furnace includes a refractory layer 1, which encloses a rectangular furnace with a front opening. The inner wall of the furnace is precision ground to prevent local bulges that could lead to stress concentration at high temperatures. A mounting frame 2 is fitted onto the inner circumferential surface of the furnace. The mounting frame 2 is made of silicon carbide reinforced ceramic matrix composite (SiC / CMC). A clearance exists between the outer contour of the mounting frame 2 and the inner circumferential surface of the furnace to accommodate the thermal expansion of components at ultra-high temperatures and to allow sufficient clearance to prevent jamming. The mounting frame 2 includes two U-shaped fixing brackets 2-1, which are spaced apart along the longitudinal direction of the furnace and fitted to fit the shape of the inner circumferential surface of the furnace. A connecting element is provided between the opposite sides of the two U-shaped fixing brackets 2-1. The partition mounting plate assembly includes multiple partition mounting plates 2-2 arranged parallel to and spaced apart along the circumference of the U-shaped fixing frame 2-1. The partition mounting plates 2-2 are made of zirconia toughened corundum ceramic. Each partition mounting plate 2-2 has a winding through hole 2-2.1 for the resistance wire 3 to pass through. At the corresponding position on the rear side of the U-shaped fixing frame 2-1 and the rear side of the refractory layer 1, there are through holes 2-1.1 for the end of the resistance wire 3 to pass through. The through holes 2-1.1 are circular holes. The resistance wire 3 is sequentially passed through the winding through holes 2-2.1 of the multiple partition mounting plates 2-2 and is tensioned and fixed between two U-shaped fixing frames 2-1. There is a gap between the resistance wire 3 and the inner circumferential surface of the refractory layer 1.

[0026] Furthermore, the two U-shaped fixing frames 2-1 are symmetrically arranged; each U-shaped fixing frame 2-1 includes two horizontally spaced parallel crossbeams 2-1.2 and two vertically spaced parallel longitudinal beams 2-1.3; the upper and lower end faces of the longitudinal beams 2-1.3 are each provided with a T-shaped locking platform 2-1.3.1, the locking platform 2-1.3.1 and the longitudinal beam 2-1.3 are integrally formed, and the locking platform 2-1.3.1 extends along the front and rear longitudinal depth of the furnace, and its extension... The extension length is shorter than the length of the longitudinal beam 2-1.3. The snap-fit ​​platform 2-1.3.1 is located on the side away from the barrier mounting plate assembly on the end face of the longitudinal beam 2-1.3. The crossbeam 2-1.2 is provided with blind grooves 2-1.2.1 adapted to the snap-fit ​​platform 2-1.3.1. After the longitudinal beam 2-1.3 is snapped and fixed to the blind grooves 2-1.2.1 of the crossbeam 2-1.2 through the snap-fit ​​platform 2-1.3.1, Al2O3-based high-temperature ceramic adhesive is applied to the snap-fit ​​joint for reinforcement, further improving the connection stability.

[0027] Furthermore, the upper and lower end faces of the barrier mounting plate 2-2 are concave arc surfaces facing each other, forming the first limiting area; multiple baffles 2-2.2 are integrally protruding from both the left and right ends of the barrier mounting plate 2-2 along the width of the furnace chamber, and the baffles 2-2.2 are spaced apart along the front and rear depth of the furnace chamber, forming a double limiting structure of "concave surface + side baffle" with the arc surface. This combined structure can reduce the lateral offset of the resistance wire 3 after it is inserted, effectively preventing the resistance wire 3 from shaking significantly due to thermal expansion or slight vibration at ultra-high temperature. Two winding through holes 2-2.1 are spaced apart along the front and rear depth of the furnace chamber on the arc surface, and are respectively set close to the two U-shaped fixing brackets 2-1; the layout of the double winding through holes 2-2.1 means that the barrier mounting plate 2-2 and the U-shaped fixing bracket 2-1 do not need to distinguish the front and back directions when installing, simplifying the assembly process.

[0028] Furthermore, both ends of the barrier mounting plate 2-2 are provided with cuboid connecting blocks 2-2.3. The two U-shaped fixing brackets 2-1 are provided with connecting holes for the connecting parts to pass through at the positions corresponding to the connecting blocks 2-2.3. When the connecting blocks 2-2.3 are engaged with the connecting holes, high-temperature ceramic thread adhesive is applied to prevent loosening.

[0029] Furthermore, there are multiple through holes 2-1.1, which are spaced apart along the circumference of the U-shaped fixing frame 2-1. The through holes 2-1.1 are staggered with the barrier mounting plate group, and each barrier mounting plate 2-2 corresponds to one through hole 2-1.1 to accommodate the lead-out requirements of the resistance wire 3 at different positions.

[0030] In Example 1, a barrier mounting plate assembly is connected between the opposite sides of the longitudinal beams 2-1.3 of the two U-shaped fixing frames 2-1. This layout allows the resistance wires 3 to be arranged along the left and right sides of the furnace, thereby achieving heating on both sides of the furnace.

[0031] In Example 2, the longitudinal beams 2-1.3 and the crossbeams 2-1.2 of the two U-shaped fixing frames 2-1 are connected to the opposite sides of the longitudinal beams 2-1.3 and the opposite sides of the crossbeams 2-1.2. This full circumferential layout allows the resistance wires 3 to be arranged around the left and right sides and the top and bottom of the furnace, so as to achieve heating of the four sides of the furnace.

[0032] The working principle of this utility model: 1. Assembly of the U-shaped fixing frame: Take the longitudinal beam 2-1.3 and the crossbeam 2-1.2 made of silicon carbide reinforced ceramic matrix composite (SiC / CMC). Apply Al2O3-based high-temperature ceramic adhesive evenly to the surface of the T-shaped locking platform 2-1.3.1 on the upper and lower end faces of the longitudinal beam 2-1.3. Then, slowly insert the T-shaped locking platform 2-1.3.1 into the matching blind groove 2-1.2.1 from one side of the crossbeam 2-1.2, ensuring that the locking platform 2-1.3.1 completely fits the inner wall of the blind groove 2-1.2.1. After the ceramic adhesive cures, a stable connection is achieved between the longitudinal beam 2-1.3 and the crossbeam 2-1.2, forming a single U-shaped fixing frame 2-1.

[0033] 2. Assembly of the barrier mounting plate and the U-shaped fixing bracket: Apply high-temperature ceramic thread-locking adhesive to the surface of the cuboid connecting blocks 2-2.3 at both ends of the barrier mounting plate 2-2. After placing the two U-shaped fixing brackets 2-1 symmetrically in the longitudinal direction of the furnace, align the connecting blocks 2-2.3 of the barrier mounting plate 2-2 with the connecting holes on the U-shaped fixing brackets 2-1 and insert them. Since the double winding through holes 2-2.1 of the barrier mounting plate 2-2 are close to the two U-shaped fixing brackets 2-1 and are symmetrically distributed, there is no need to distinguish the positive and negative directions when inserting them; simply align them with the connecting holes.

[0034] 3. Installation of resistance wire: Pass one end of resistance wire 3 through the circular through hole (through hole 2-1.1) of the rear-side U-shaped fixing frame 2-1 of the furnace and the corresponding through hole on the rear side of the refractory layer 1 in sequence; lay the remaining resistance wire 3 along the length of the upper barrier mounting plate 2-2 to its winding through hole 2-2.1, pass it down to the lower barrier mounting plate 2-2, and then lay it in the opposite direction along the length of the lower barrier mounting plate 2-2. Because the winding through hole 2-2.1 of the barrier mounting plate 2-2 is set along the longitudinal direction of the furnace, the resistance wire 3 is finally distributed in an S-shape between adjacent barrier mounting plates 2-2.

[0035] 4. Multi-layer winding of resistance wire: Multiple layers of resistance wire 3 can be wound according to the heating power requirements; Since multiple through holes 2-1.1 on the U-shaped fixing frame 2-1 are opened circumferentially, and the through holes 2-1.1 are staggered with the barrier mounting plate group, each barrier mounting plate 2-2 corresponds to one through hole 2-1.1, which can meet the end lead-out requirements of resistance wire 3 with different layers.

[0036] 5. Limiting and fixing the resistance wire: After the resistance wire 3 is installed, the opposing concave arc surfaces on the upper and lower end faces of the barrier mounting plate 2-2 form the first limiting area, which initially constrains the displacement of the resistance wire 3. At the same time, multiple baffles 2-2.2 (arranged at intervals along the longitudinal direction of the furnace) on both the left and right ends of the barrier mounting plate 2-2 along the width of the furnace cooperate with the arc surface to form a double limiting structure of "concave surface + side baffle", which can effectively constrain the offset of the resistance wire 3 and prevent the resistance wire 3 from shaking significantly due to thermal expansion or vibration at ultra-high temperature.

[0037] 6. Assembly of the mounting frame: The mounting frame 2 (including the U-shaped fixing frame 2-1, the barrier mounting plate 2-2, and the resistance wire 3) that has been adapted to the resistance wire 3 is smoothly pushed into the furnace from the opening on the front side of the furnace along the fitting gap of the inner circumference of the furnace. Ensure that the outer contour of the mounting frame 2 fits the inner circumference of the furnace to complete the assembly of the furnace lining structure. After being pushed in, there is a gap between the resistance wire 3 and the inner circumference of the refractory layer 1.

[0038] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A furnace lining structure for a box-type resistance furnace, comprising a refractory layer, the refractory layer enclosing a furnace chamber with a front opening, characterized in that, An installation frame is fitted onto the inner circumferential surface of the furnace. The mounting frame includes two U-shaped fixing brackets, which are arranged at intervals along the front and rear longitudinal direction of the furnace and are adapted to fit the shape of the inner circumferential surface of the furnace. A barrier mounting plate assembly is connected between the opposite sides of the two loop-shaped fixing frames. The barrier mounting plate assembly includes multiple barrier mounting plates that are parallel and spaced apart along the circumference of the loop-shaped fixing frames. Each barrier mounting plate has a winding through hole for the resistance wire to pass through. The U-shaped fixing frame located at the rear side of the furnace and the corresponding position at the rear side of the refractory layer are both provided with through holes for the end of the resistance wire to pass through. The resistance wire is sequentially threaded through the winding through holes of the multiple barrier mounting plates and tensioned and fixed between the two U-shaped fixing frames, with a gap between the resistance wire and the inner circumferential surface of the fire-resistant layer.

2. The furnace lining structure of the box-type resistance furnace according to claim 1, characterized in that, The two loop-shaped fixing frames are arranged symmetrically; Each of the U-shaped fixing frames includes two horizontal beams arranged parallel to each other in the horizontal direction, and two vertical beams arranged parallel to each other in the vertical direction. The upper and lower end faces of the longitudinal beam are provided with T-shaped snap-fit ​​platforms. The snap-fit ​​platforms extend along the front and rear longitudinal direction of the furnace, and their extension length is shorter than the length of the longitudinal beam. The snap-fit ​​platforms are located on the side of the longitudinal beam end face that is away from the barrier mounting plate group. Each of the crossbeams is provided with a blind groove for a matching snap-fit ​​platform, and the longitudinal beams are fixed to the crossbeams by snap-fit ​​platforms through the blind grooves.

3. The furnace lining structure of the box-type resistance furnace according to claim 1, characterized in that, The upper and lower end faces of the barrier mounting plate are concave arc surfaces facing each other; the barrier mounting plate is integrally provided with multiple baffles at the left and right ends along the width direction of the furnace chamber, and the baffles are arranged at intervals along the front and rear depth direction of the furnace chamber. Two winding through holes are provided at intervals along the front and rear depth direction of the furnace chamber on the arc surface, and the two winding through holes are respectively located close to the two U-shaped fixing frames.

4. The furnace lining structure of the box-type resistance furnace according to claim 1, characterized in that, Both ends of the barrier mounting plate are provided with connecting blocks, and the two U-shaped fixing brackets are provided with connecting holes for the connecting parts to pass through at the corresponding positions of the connecting blocks.

5. The furnace lining structure of the box-type resistance furnace according to claim 1, characterized in that, There are multiple through holes, which are spaced apart along the circumference of the U-shaped fixing frame. The through holes are staggered with the barrier mounting plate group, and each barrier mounting plate corresponds to one through hole.

6. The furnace lining structure of the box-type resistance furnace according to claim 2, characterized in that, A barrier mounting plate assembly is connected between the opposite sides of the longitudinal beams of the two U-shaped fixing frames.

7. The furnace lining structure of the box-type resistance furnace according to claim 2, characterized in that, The barrier mounting plate assembly is connected between the opposite sides of the longitudinal beams and the opposite sides of the transverse beams of the two U-shaped fixing frames.

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