Continuous sintering furnace

Abstract

The invention belongs to the technical field of sintering, and particularly relates to a continuous sintering furnace. Comprising a preparation furnace, the rear side of the preparation furnace is sequentially and detachably communicated with a row of sintering furnaces, an aging furnace and a cooling furnace, vacuum pumps are installed on the side wall of the preparation furnace, the side wall of the cooling furnace and the side wall of one of the sintering furnaces, and gates are installed at the communicating position of every two adjacent sintering furnaces and the communicating position of the sintering furnace on the rearmost side and the aging furnace. Sealing pieces are arranged on the front side and the rear side of the preparation furnace and the communicating position of the aging furnace and the cooling furnace, conveying rollers arranged in the conveying direction are arranged in the preparation furnace, the sintering furnace, the aging furnace and the cooling furnace, and conveying frames are placed on the conveying rollers. The inner frame is designed to be of a flat structure with the width larger than the height, and the heating rods are arranged on the two sides, so that the transverse heat conduction path is effectively shortened, heat acts on neodymium-iron-boron green bodies stacked in a short-wide mode more evenly, the problem of temperature rise lag of a center area is remarkably solved, and sintering uniformity and density are improved.

Description

Technical Field

[0001] This invention belongs to the field of sintering technology, and specifically relates to a continuous sintering furnace. Background Technology

[0002] In the sintering process of NdFeB permanent magnet materials, the heating uniformity and thermal efficiency of the sintering furnace directly determine the density, microstructure uniformity, and final magnetic property consistency of the product. Currently, conventional sintering furnaces typically have heating rods arranged on the four sides (top, bottom, left, and right) of the furnace chamber to heat the NdFeB billets stacked in the center of the furnace cavity through radiation from the outside in. However, in actual production, the height and width of the billet stacks are often similar, and the stack density is high, resulting in significant thermal resistance during heat transfer from the outside to the inside. The central region of the stack experiences delayed heating, and the temperature field distribution is uneven, making it difficult to achieve efficient and uniform sintering. Reducing the stack height or decreasing the loading to improve heat conduction would lead to a decrease in furnace cavity space utilization, an increase in unit energy consumption, and energy waste.

[0003] To improve thermal uniformity, some existing sintering furnaces employ a front and rear heating structure, and design the NdFeB stacks as a narrow-width-high configuration with a height-to-width ratio of approximately 3:1 to shorten the lateral heat conduction path. While this approach improves temperature uniformity to some extent, the excessively high center of gravity and narrow support surface result in poor stability during transport, making them prone to tipping over, causing product damage or even equipment failure. To address this issue, the industry commonly uses a top-hanging method for transporting the billets within the furnace. However, the moving parts of the hanging device are constantly exposed to a high-temperature (typically exceeding 1000°C) sintering environment, necessitating the use of high-temperature resistant special alloys or ceramic materials. This not only significantly increases manufacturing costs but also leads to complex structures, difficult maintenance, and limited reliability.

[0004] Furthermore, existing sintering furnaces generally employ built-in roller conveyor structures, with their support bearings directly installed inside the insulation layer. Under continuous high temperatures, these bearings are prone to lubrication failure, thermal deformation, and even seizing, significantly shortening their service life. At the same time, the limited space inside the furnace makes the installation, replacement, and routine maintenance of the bearings extremely inconvenient, further reducing the overall reliability and maintainability of the equipment. Summary of the Invention

[0005] In view of this, the present invention provides a continuous sintering furnace.

[0006] The technical embodiment of the present invention is as follows: A continuous sintering furnace includes a preparation furnace. A row of sintering furnaces, an aging furnace, and a cooling furnace are detachably connected sequentially to the rear side of the preparation furnace. Vacuum pumps are installed on the side walls of the preparation furnace, the cooling furnace, and one of the sintering furnaces. Gates are installed at the connections between adjacent sintering furnaces and at the connection between the last sintering furnace and the aging furnace. Sealing elements are provided on the front and rear sides of the preparation furnace and at the connection between the aging furnace and the cooling furnace. Conveying rollers arranged along the conveying direction are provided inside the preparation furnace, the sintering furnace, the aging furnace, and the cooling furnace. Conveying frames are placed on the conveying rollers. Mounting frames are connected inside the sintering furnace and the aging furnace. The sintering furnace and the aging furnace are equipped with a sintering frame and an inner frame. Multiple insulation layers are provided between the mounting frame and the inner frame. Conductive rods are installed on both the sintering furnace and the aging furnace, passing through the mounting frame, insulation layers, and inner frame. The inner frame has a flat structure with a width greater than its height. Heating rods are installed at the ends of the conductive rods on both sides inside the inner frame. The heating rods are powered by a single-end connection, with the conductive rod connected to one end of the heating rod and the other end electrically connected to the furnace shell of the sintering furnace or aging furnace, forming a power supply circuit. The bearing assembly of the conveying roller is located outside the furnace body of the sintering furnace and the aging furnace, and the conveying roller penetrates the furnace wall through a high-temperature resistant sealing structure.

[0007] More preferably, the ratio of the internal height to the width of the inner frame is less than or equal to 1:2.

[0008] More preferably, the sealing element includes a connecting frame, a cylinder, a guide rail, a lifting plate, a hinge rod, a sealing door, rollers, and a fixing block. Connecting frames are attached to the front and rear sides of the preparation furnace and the connection points between the aging furnace and the cooling furnace. A square hole for the conveying frame to pass through is opened in the middle of each connecting frame. A cylinder is connected to each connecting frame. A pair of guide rails are connected inside each connecting frame. A lifting plate located inside the connecting frame is connected to the movable rod of each cylinder. A sealing door for sealing the square hole is provided on the rear side of the lifting plate. Two sets of inclined hinge rods are rotatably connected between the lifting plate and the sealing door. The upper and lower hinge rods are parallel. A pair of rollers are rotatably installed on both sides of the lifting plate, and the rollers on the lifting plate roll along the guide rails. A roller is rotatably installed on both sides of the sealing door. Fixing blocks are connected to both sides of the inner wall of the connecting frame, and the rollers on the sealing door are located directly above the fixing blocks.

[0009] More preferably, the seal also includes a pressure sensor, which is installed on the side wall of the sealing door, and the lifting plate will come into contact with the pressure sensor when it descends.

[0010] More preferably, the preparation furnace, sintering furnace, aging furnace and cooling furnace are all provided with protective gas inlets, and the bottom of the preparation furnace, sintering furnace, aging furnace and cooling furnace are all equipped with casters.

[0011] More preferably, the continuous sintering furnace also includes a heat dissipation mechanism, which includes a horizontal radiator. The horizontal radiator is installed on the lower side of the interior of the cooling furnace, and vertical radiators are provided on both sides of the horizontal radiator. A fan is installed at the bottom of the cooling furnace below the horizontal radiator. Two cold air guide plates are provided in the middle of the interior of the cooling furnace, and the top of each cold air guide plate has an arc-shaped part. Two arc-shaped hot air guide plates are provided at the top of the interior of the cooling furnace, and a side plate is provided at the rear of the cooling furnace.

[0012] More preferably, the heat dissipation mechanism also includes a lifting door, a lifting rod, a synchronous pulley, and a synchronous belt. The top of the cooling furnace is provided with a lifting rod driven by a hydraulic cylinder. Both ends of the lifting rod are rotatably connected to synchronous pulleys. The rear side of the side plate is provided with a lifting door that slides up and down. Two synchronous belts are connected between the lifting door and the top of the cooling furnace. The synchronous belts are wound around the synchronous pulleys.

[0013] More preferably, the heat dissipation mechanism also includes cooling pipe one and cooling pipe two, with cooling pipe one installed on the side plate and cooling pipe two installed on the lifting door, and both cooling pipe one and cooling pipe two are distributed in a serpentine pattern.

[0014] More preferably, it also includes a high-frequency inverter power supply system, which is electrically connected to the conductive rod; the high-frequency inverter power supply system includes a rectifier unit, an IGBT inverter unit and a high-frequency transformer connected in sequence, for converting three-phase AC power into high-frequency AC power with a frequency of 10KHz to power the heating rod.

[0015] Compared with the prior art, the present invention has the following advantages: 1. By designing the inner frame as a flat structure with a width greater than its height and arranging heating rods on both sides, the lateral heat conduction path is effectively shortened, allowing heat to be applied more evenly to the short and wide NdFeB billets. This significantly improves the problem of lag in heating in the central area, enhancing sintering uniformity and density. Simultaneously, the sintering furnace forms a stepped heating zone along the conveying direction. Combined with the continuous structure consisting of a preparation furnace, multi-stage sintering furnace, aging furnace, and cooling furnace, and the coordinated control of gates and seals, efficient continuous operation is achieved: while the current batch is sintering, the next batch of material can be placed in the preparation furnace; the front sealing door achieves micro-movement closure through a lifting plate and hinged rod mechanism, tightly sealing gaps and reducing heat loss; after vacuuming, protective gas is pre-filled into the preparation furnace to ensure the atmosphere is consistent with the sintering zone. After sintering, all gates and sealing doors open synchronously, and the conveying rollers drive the material to move backward as a whole, directly entering the next temperature zone without stopping. This design integrates atmosphere pre-conditioning, graded temperature control, and continuous flow, significantly shortening the process cycle and improving sintering efficiency, energy efficiency, and product consistency.

[0016] 2. The bearing assembly of the conveyor roller is located outside the furnace body and penetrates the furnace wall through a high-temperature resistant sealing structure, which avoids lubrication failure, deformation or jamming caused by the bearing being in a high-temperature environment for a long time, and significantly extends the service life. In addition, the multi-section furnace body is detachably connected, which facilitates on-site assembly, maintenance and replacement, and improves the maintainability and operational stability of the whole machine.

[0017] 3. The insulation layer thickness has been increased to 200mm. This thicker insulation layer effectively blocks the transfer of high-temperature heat to the furnace shell, significantly reducing the surface temperature of the furnace shell. Therefore, the furnace shell no longer needs to rely on large-flow cooling water for forced cooling, which not only simplifies the cooling system structure but also significantly reduces energy consumption, improves the energy-saving and environmental protection performance of the equipment, and enhances the safety and comfort of the operating environment.

[0018] 4. Control the fan to blow air. Under the action of the horizontal and vertical radiators, the cold air blows along the arc of the cold air guide plate to the material in the conveying frame. The hot air that takes away the heat blows upward to the hot air guide plate. The hot air guide plate guides the hot air to the left and right sides. Cooling pipe one and cooling pipe two, which are connected to cooling water, cool the hot air, realize directional air cooling and rapid hot air discharge, uniform cooling and increase heat exchange area, and improve cooling efficiency.

[0019] 5. Existing technologies require two electrodes for each heating stage, while this invention uses only one electrode, with the other introduced through the furnace shell. This simplifies the structure and reduces costs.

[0020] 6. Traditional power supplies use magnetically adjustable transformers, controlling the voltage by adjusting the conduction angle of the transformer's primary winding. This reduces the power factor and increases pollution to the power grid. This invention rectifies three-phase electricity into DC, then uses IGBTs to convert the DC into 10kHz AC, which is then used to power the electric furnace. The power factor is almost equal to 1, and the impact and pollution on the power grid are reduced. Because the frequency is much higher than 50Hz, the amount of copper and iron core in the transformer is significantly reduced, lowering costs.

[0021] 7. Due to the characteristics of the sintering process for NdFeB, the entire sintering process is carried out under vacuum conditions. Therefore, gas isolation is not required between multiple sintering chambers; only temperature isolation is needed. This simplifies the structure by requiring only one heat insulation plate, eliminating the need for sealing or cooling, and more importantly, reducing heat loss by 80%. This results in significant energy savings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 The diagram shows the structure of the furnace, seal, conveying roller and conveying frame for the present invention, wherein the connecting frame is cut open.

[0024] Figure 3 This is a front view of the seal of the present invention.

[0025] Figure 4 This is a side view of the lifting plate, hinge rod, sealing door, rollers, and pressure sensor of the present invention.

[0026] Figure 5 This is a schematic diagram of the internal structure of the furnace used in this invention.

[0027] Figure 6 This is a schematic diagram of the internal structure of the aging furnace of the present invention.

[0028] Figure 7 This is a schematic diagram of the sintering furnace and gate of the present invention.

[0029] Figure 8 This is a schematic diagram of the structure of the mounting frame, insulation layer, gate, conveying roller and conveying frame of the present invention.

[0030] Figure 9 This is a schematic diagram of the structure of the insulation layer, inner frame, conveying roller, and conveying frame of the present invention.

[0031] Figure 10 This is a schematic diagram of the structure of the inner frame, conductive rod, heating rod, conveying roller and conveying frame of the present invention.

[0032] Figure 11 This is a schematic diagram of the cooling furnace and its components according to the present invention.

[0033] Figure 12 This is a rear view of the internal structure of the cooling furnace of the present invention.

[0034] Figure 13 This is a rear view of the side panel, lifting door, lifting rod, synchronous belt, cooling pipe one, and cooling pipe two of the present invention.

[0035] Figure 14 This is a circuit diagram of the high-frequency inverter power supply system of the present invention.

[0036] The components in the attached diagram are labeled as follows: 1-Preparation furnace, 101-Protective gas inlet, 102-Moving wheel, 2-Sintering furnace, 201-Mounting frame, 202-Insulation layer, 203-Inner frame, 204-Conductive rod, 205-Heating rod, 3-Aging furnace, 4-Cooling furnace, 41-Horizontal radiator, 42-Vertical radiator, 43-Fan, 44-Cold air guide plate, 45-Arc-shaped part, 46-Hot air guide plate, 47- Side plate, 471-Lifting door, 472-Lifting rod, 473-Synchronous pulley, 474-Synchronous belt, 475-Cooling pipe one, 476-Cooling pipe two, 5-Vacuum pump, 6-Gate, 7-Seal, 71-Connecting frame, 72-Cylinder, 73-Guide rail, 74-Lifting plate, 75-Hinge rod, 76-Sealing door, 77-Roller, 78-Fixing block, 79-Pressure sensor, 8-Conveying roller, 80-Conveying frame. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] A continuous sintering furnace, reference Figures 1-14The system includes a preparation furnace 1, a sintering furnace 2, an aging furnace 3, a cooling furnace 4, a vacuum pump 5, a gate 6, a sealing element 7, a conveying roller 8, and a conveying frame 80. A row of sintering furnaces 2, an aging furnace 3, and a cooling furnace 4 are detachably connected to the rear side of the preparation furnace 1, facilitating modular assembly and maintenance. Each of the preparation furnace 1, sintering furnace 2, aging furnace 3, and cooling furnace 4 has a protective gas inlet 101 on its side wall for introducing inert or reducing protective atmospheres such as argon or nitrogen to prevent oxidation of the NdFeB material at high temperatures. Each of the preparation furnace 1, sintering furnace 2, aging furnace 3, and cooling furnace 4 is equipped with a set of casters 102 at its bottom for easy transport and on-site positioning. Vacuum pumps 5 are installed on the side walls of the preparation furnace 1, cooling furnace 4, and the sintering furnace 2 adjacent to the preparation furnace 1, allowing for independent vacuuming of the corresponding furnace sections. Gates 6 are installed at the connections between adjacent sintering furnaces 2 and between the last sintering furnace 2 and the aging furnace 3, enabling zoned temperature control. The gate plates of the gates 6 are made of high-temperature resistant heat-insulating material. Since the entire process is carried out under vacuum or a protective atmosphere, there is no need to maintain an atmosphere difference between adjacent sintering furnaces 2 or between sintering furnace 2 and the aging furnace 3; therefore, temperature isolation is only required through the gates 6. This gate 6 eliminates the need for complex gas sealing structures and cooling water channels, greatly simplifying the structure and avoiding the significant heat loss caused by traditional water-cooled gates. Sealing elements 7 are installed on both the front and rear sides of the preparation furnace 1, and at the connection points between the aging furnace 3 and the cooling furnace 4, to ensure the overall airtightness of the furnace body. The preparation furnace 1, sintering furnace 2, aging furnace 3, and cooling furnace 4 are all equipped with conveying rollers 8 arranged along the conveying direction. Conveying frames 80 are placed on the conveying rollers 8, and the interior of the conveying frames 80 is used to stack NdFeB billets. The conveying rollers 8 are used to continuously convey the conveying frames 80 carrying the NdFeB billets. To improve stacking stability and adapt to the heat field distribution, the conveying frames 80 are designed as rectangular structures with a height less than their width, and the four sides... Equipped with sidewalls, the bearing assembly of the conveying roller 8 is located outside the furnace bodies of the sintering furnace 2 and the aging furnace 3. The conveying roller 8 penetrates the furnace wall through a high-temperature resistant dynamic sealing structure, effectively preventing the bearings from being exposed to a high-temperature environment for a long time, significantly improving service life and facilitating maintenance. Both the sintering furnace 2 and the aging furnace 3 are internally connected to an installation frame 201 and an inner frame 203. The inner frame 203 forms a heating chamber, whose internal cavity adopts a flat structure with a width greater than its height to shorten the lateral heat conduction path and matches a low-width stacking form to improve heating uniformity. Multiple layers of insulation 202 are provided between the installation frame 201 and the inner frame 203, with its total thickness significantly increased from the traditional approximately 60mm to 200mm. The thickened insulation layer effectively blocks the transfer of high-temperature heat to the furnace shell, significantly reducing the surface temperature of the furnace shell. Therefore, the furnace shell does not need to rely on large-flow cooling water for forced cooling, which not only simplifies the cooling system structure but also significantly reduces energy consumption, improves the energy-saving and environmentally friendly performance of the equipment, and enhances the safety and comfort of the operating environment.Both the sintering furnace 2 and the aging furnace 3 are equipped with conductive rods 204. The conductive rods 204 pass through the mounting frame 201, the insulation layer 202, and the inner frame 203. Heating rods 205 are installed at the ends of the conductive rods 204 that extend into the inner frame 203. The heating rods 205 are symmetrically distributed vertically within the inner frame 203, and the power supply to the heating rods 205 is a single-end introduction method. Specifically, the conductive rods 204 introduce current to one end of the heating rods 205, while the other end of the heating rods 205 is electrically connected to the furnace shell of the sintering furnace 2 or the aging furnace 3, using the furnace shell as a loop conductor.

[0039] refer to Figures 2-4 The sealing element 7 includes a connecting frame 71, a cylinder 72, a guide rail 73, a lifting plate 74, a hinge rod 75, a sealing door 76, a roller 77, and a fixing block 78. Connecting frames 71 are fixedly connected to the front and rear sides of the preparation furnace 1 and to the connection points between the aging furnace 3 and the cooling furnace 4. A square hole for the conveying frame 80 to pass through is opened in the middle of each connecting frame 71. A cylinder 72 is bolted to the top of each connecting frame 71. A pair of guide rails 73 are fixedly connected inside each connecting frame 71. A lifting plate 74 located inside the connecting frame 71 is connected to the movable rod of each cylinder 72. A sealing door 76 for sealing the square hole is provided on the rear side of the lifting plate 74. Two sets of inclined hinge rods 75 are rotatably connected between the lifting plate 74 and the sealing door 76. The hinge rod 75 is parallel to the lower hinge rod 75. A pair of rollers 77 are rotatably installed on both sides of the lifting plate 74. The rollers 77 on the lifting plate 74 roll along the guide rail 73. A roller 77 is rotatably installed on both sides of the sealing door 76. Fixing blocks 78 are fixedly connected to both sides of the inner wall of the connecting frame 71. The rollers 77 on the sealing door 76 are located directly above the fixing blocks 78. The sealing element 7 also includes a pressure sensor 79. A pressure sensor 79 is installed on the side wall of the sealing door 76. When the lifting plate 74 descends, it will contact the pressure sensor 79. A controller is installed on the preparation furnace 1. The controller is prior art and is not shown in the figure. The pressure sensor 79 and the cylinder 72 are electrically connected to the controller.

[0040] refer to Figures 11-13The continuous sintering furnace also includes a heat dissipation mechanism, which includes a horizontal radiator 41, a vertical radiator 42, a fan 43, a cold air guide plate 44, a hot air guide plate 46, and a side plate 47. A horizontal radiator 41 is installed on the lower side inside the cooling furnace 4, and vertical radiators 42 are installed on both sides of the horizontal radiator 41. A fan 43 is installed below the horizontal radiator 41 at the bottom of the cooling furnace 4. Two cold air guide plates 44 are located in the middle inside the cooling furnace 4, and each cold air guide plate 44 has an arc-shaped part 45 at its top. Two arc-shaped hot air guide plates 46 are located at the top inside the cooling furnace 4. The fan 43 blows air, and the cold air cooled by the horizontal radiator 41 and the vertical radiator 42 is blown along the cold air guide plate 44 towards the conveyor frame 80. The hot air guide plate 46 then guides the hot air to... On both sides, a side plate 47 is provided on the rear side of the cooling furnace 4; the heat dissipation mechanism also includes a lifting door 471, a lifting rod 472, a synchronous pulley 473 and a synchronous belt 474. The top of the cooling furnace 4 is provided with a lifting rod 472 driven by a hydraulic cylinder. The left and right ends of the lifting rod 472 are rotatably connected to the synchronous pulley 473. The rear side of the side plate 47 is provided with a lifting door 471 that slides up and down. Two synchronous belts 474 are connected between the lifting door 471 and the top of the cooling furnace 4. The synchronous belts 474 are wrapped around the synchronous pulley 473. The heat dissipation mechanism also includes a first cooling pipe 475 and a second cooling pipe 476. Two first cooling pipes 475 are installed on the side plate 47, and the second cooling pipe 476 is installed on the lifting door 471. Both the first cooling pipe 475 and the second cooling pipe 476 are distributed in a serpentine pattern.

[0041] Initially, conveyor frames 80 are placed on the conveyor rollers 8 inside the sintering furnace 2, and neodymium iron boron material is placed inside the conveyor frames 80. The frontmost sealing door 76 is open, while the gate 6 and other sealing doors 76 are closed. Both the sintering furnace 2 and the cooling furnace 4 are evacuated and filled with protective gas. Power is supplied through the conductive rod 204, whose power input is connected to a high-frequency inverter power supply system. To solve the problems of low power factor and grid pollution caused by traditional thyristor voltage regulation, this system adopts IGBT inverter technology. Specifically, the power supply system first rectifies the three-phase AC power into DC power, then uses an IGBT module to invert the DC power into high-frequency AC power with a frequency of 10kHz, and finally steps it down through a high-frequency step-down transformer to power the heating rod 205. The high-frequency power supply system heats the heating rod 205 inside the sintering furnace 2, and the sintering temperature inside the sintering furnace 2 increases in a stepwise manner from front to back, thereby sintering the material inside the sintering furnace 2.

[0042] While sintering the material, a conveyor frame 80 containing the next batch of material to be sintered is placed on the conveyor rollers 8 inside the preparation furnace 1. The cylinder 72 at the front drives the lifting plate 74 at the front to descend. The rollers 77 on the lifting plate 74 roll along the guide rail 73. The lifting plate 74 drives the hinge rod 75, pressure sensor 79, and rollers 77 on the sealing door 76 to descend together. When the rollers 77 on the sealing door 76 contact the fixed block 78, the sealing door 76, pressure sensor 79, and rollers 77 on the sealing door 76 stop descending, while the cylinder 72 causes the lifting plate 74 to descend. 4. As the furnace continues to descend, the hinge rod 75 rotates, and the lifting plate 74 applies a backward squeezing force to the sealing door 76 through the hinge rod 75, causing the sealing door 76 to move slightly backward and close. The sealing door 76 presses against the square hole around the connecting frame 71, preventing subsequent heat from passing through the gap between the sealing door 76 and the connecting frame 71. The pressure sensor 79 detects the downward pressure from the lifting plate 74, thereby detecting the descent position of the lifting plate 74, which facilitates the control of the descent height of the lifting plate 74. This helps to control the temperature inside the sintering furnace 2, saving energy and improving the heat preservation effect.

[0043] Then, the vacuum pump 5 is controlled to evacuate the preparation furnace 1. After evacuation, protective gas is introduced into the preparation furnace 1 through the protective gas inlet 101, thereby adjusting the gas environment in the preparation furnace 1 to be consistent with the gas environment in the sintering furnace 2.

[0044] After one sintering process is completed, the central cylinder 72 and the rear cylinder 72 are controlled to raise the corresponding lifting plate 74, which drives the hinge rod 75, sealing door 76 and roller 77 to rise and reset. The central sealing door 76 and the rear sealing door 76 are opened, and all gates 6 are opened. Then, the conveying roller 8 is controlled to rotate, and the conveying roller 8 conveys all the conveying frames 80 and materials to the next position. The materials in the preparation furnace 1 enter the first sintering furnace 2, the materials in the first sintering furnace 2 enter the second sintering furnace 2 for sintering at the next temperature, and the materials in the last sintering furnace 2 enter the aging furnace 3 for heat preservation. Then, the central cylinder 72 is controlled to raise the central sealing door 76. The sealing door 76 on the rear side is closed, and all gates 6 are closed. At this time, the material in the sintering furnace 2 can be sintered by heating rod 205. During the sintering process, the sealing door 76 on the front side is opened again, and the next batch of material is put into the preparation furnace 1 and vacuumed and filled with protective gas. In this way, the gas environment can be adjusted in advance during the sintering process. After sintering, the material is directly put into the next position for sintering at the next temperature by conveying roller 8, which reduces waiting time, allows for graded controllable and continuous sintering, improves sintering efficiency, reduces temperature fluctuations, reduces atmosphere purity decay, and reduces performance differences between batches, so as to achieve low energy consumption and high consistency of material mass production.

[0045] When the middle sealing door 76, the rear sealing door 76, and the gate 6 are opened again, the conveying roller 8 conveys the conveying frame 80 and the material to the rear again. The conveying frame 80 and the material in the aging furnace 3 enter the cooling furnace 4. After the middle sealing door 76, the rear sealing door 76, and the gate 6 are closed, the fan 43 can be controlled to blow air. Under the action of the horizontal radiator 41 and the vertical radiator 42, the cold air blows along the arc-shaped part 45 of the cold air guide plate 44 to the material in the conveying frame 80, thereby cooling the material. The hot air that takes away the heat blows upward to the hot air guide plate 46. The hot air guide plate 46 guides the hot air to the left and right sides. At the same time, the cooling pipe 1 475 and the cooling pipe 2 476 that are connected to the cooling water cool the hot air. In this way, the cold air guide plate 44 and the hot air guide plate 46 can effectively guide the air, realize directional air cooling and rapid hot air output, uniform cooling, avoid local overheating that causes micro-cracks in the magnet, and increase the heat exchange area and improve the cooling efficiency.

[0046] After the material in the cooling furnace 4 has cooled, the hydraulic cylinder drives the lifting rod 472 to rise, which in turn drives the synchronous pulley 473 to rise. The synchronous pulley 473 pulls the synchronous belt 474, which in turn pulls the lifting door 471 to rise and open, allowing the cooled conveyor frame 80 and the material to be removed. Then, the hydraulic cylinder is controlled to lower the lifting rod 472 and the synchronous pulley 473, and the lifting door 471 closes under gravity. The vacuum pump 5 is then used to evacuate the cooling furnace 4, and protective gas is introduced into the cooling furnace 4 through the protective gas inlet 101 to prevent the sealing door 76 and the gate 6 from affecting the gas environment inside the sintering furnace 2 when they are reopened.

Claims

1. A continuous sintering furnace, comprising a preparation furnace (1), characterized in that: The rear side of the preparation furnace (1) is detachably connected to a row of sintering furnaces (2), an aging furnace (3), and a cooling furnace (4). Vacuum pumps (5) are installed on the side walls of the preparation furnace (1), the cooling furnace (4), and one of the sintering furnaces (2). Gates (6) are installed at the connection points between two adjacent sintering furnaces (2) and at the connection point between the last sintering furnace (2) and the aging furnace (3). Sealing elements (7) are provided on the front and rear sides of the preparation furnace (1) and at the connection points between the aging furnace (3) and the cooling furnace (4). Conveying rollers (8) arranged along the conveying direction are provided inside the preparation furnace (1), the sintering furnace (2), the aging furnace (3), and the cooling furnace (4). Conveying frames (80) are placed on the conveying rollers (8). The sintering furnace (2) and the aging furnace (3) are connected to an installation frame (201) and an inner frame (203). The installation frame (201) and the inner frame (203) are connected to each other. Multiple insulation layers (202) are provided between the sintering furnace (2) and the aging furnace (3). Conductive rods (204) are installed on both the sintering furnace (2) and the aging furnace (3). The conductive rods (204) pass through the mounting frame (201), the insulation layer (202) and the inner frame (203). The internal cavity of the inner frame (203) is a flat structure with a width greater than its height. Heating rods (205) located on both sides inside the inner frame (203) are installed at the ends of the conductive rods (204). The heating rods (205) are powered by a single-end introduction method. The conductive rods (204) are connected to one end of the heating rods (205), and the other end of the heating rods (205) is electrically connected to the furnace shell of the sintering furnace (2) or the aging furnace (3) to form a power supply circuit. The bearing assembly of the conveying roller (8) is located outside the furnace body of the sintering furnace (2) and the aging furnace (3). The conveying roller (8) penetrates the furnace wall through a high-temperature resistant sealing structure.

2. A continuous sintering furnace according to claim 1, characterized in that: The ratio of the internal height to the width of the inner frame (203) is less than or equal to 1:

2.

3. A continuous sintering furnace according to claim 1, characterized in that: The sealing element (7) includes a connecting frame (71), a cylinder (72), a guide rail (73), a lifting plate (74), a hinge rod (75), a sealing door (76), a roller (77), and a fixing block (78). The front and rear sides of the preparation furnace (1) and the connection points between the aging furnace (3) and the cooling furnace (4) are all connected to the connecting frame (71). The connecting frame (71) has a square hole in the middle for the conveying frame (80) to pass through. The connecting frame (71) is connected to a cylinder (72). The connecting frame (71) is connected to a pair of guide rails (73). The moving rod of the cylinder (72) is connected to a lifting plate (74) located inside the connecting frame (71). The lifting plate (74) is provided with a sealing door (76) for sealing the square hole. The lifting plate (74) and the sealing door (76) are rotatably connected by two sets of inclined hinge rods (75). The upper hinge rod (75) and the lower hinge rod (75) are parallel. A pair of rollers (77) are rotatably installed on both sides of the lifting plate (74). The rollers (77) on the lifting plate (74) roll along the guide rail (73). A roller (77) is rotatably installed on both sides of the sealing door (76). Fixed blocks (78) are connected to both sides of the inner wall of the connecting frame (71). The rollers (77) on the sealing door (76) are located directly above the fixed blocks (78).

4. A continuous sintering furnace according to claim 3, characterized in that: The seal (7) also includes a pressure sensor (79), and the pressure sensor (79) is installed on the side wall of the sealing door (76). When the lifting plate (74) descends, it will come into contact with the pressure sensor (79).

5. A continuous sintering furnace according to claim 1, characterized in that: The preparation furnace (1), sintering furnace (2), aging furnace (3) and cooling furnace (4) are all equipped with protective gas filling ports (101), and the bottom of the preparation furnace (1), sintering furnace (2), aging furnace (3) and cooling furnace (4) are all equipped with casters (102).

6. A continuous sintering furnace according to claim 1, characterized in that: The continuous sintering furnace also includes a heat dissipation mechanism, which includes a horizontal radiator (41). The horizontal radiator (41) is installed on the lower side inside the cooling furnace (4). Vertical radiators (42) are provided on both sides of the horizontal radiator (41). A fan (43) is installed at the lower part of the cooling furnace (4) below the horizontal radiator (41). Two cold air guide plates (44) are provided in the middle inside the cooling furnace (4). The top of each cold air guide plate (44) has an arc-shaped part (45). Two arc-shaped hot air guide plates (46) are provided at the top inside the cooling furnace (4). A side plate (47) is provided at the rear side of the cooling furnace (4).

7. A continuous sintering furnace according to claim 6, characterized in that: The heat dissipation mechanism also includes a lifting door (471), a lifting rod (472), a synchronous pulley (473), and a synchronous belt (474). The top of the cooling furnace (4) is provided with a lifting rod (472) driven by a hydraulic cylinder. Both ends of the lifting rod (472) are rotatably connected to synchronous pulleys (473). The rear side of the side plate (47) is provided with a lifting door (471) that slides up and down. Two synchronous belts (474) are connected between the lifting door (471) and the top of the cooling furnace (4). The synchronous belts (474) are wrapped around the synchronous pulleys (473).

8. A continuous sintering furnace according to claim 7, characterized in that: The heat dissipation mechanism also includes cooling pipe one (475) and cooling pipe two (476). Cooling pipe one (475) is installed on the side plate (47), and cooling pipe two (476) is installed on the lifting door (471). Cooling pipe one (475) and cooling pipe two (476) are both distributed in a serpentine pattern.

9. A continuous sintering furnace according to claim 1, characterized in that: It also includes a high-frequency inverter power supply system, which is electrically connected to the conductive rod (204); the high-frequency inverter power supply system includes a rectifier unit, an IGBT inverter unit and a high-frequency transformer connected in sequence, which are used to convert three-phase AC power into high-frequency AC power with a frequency of 10KHz to power the heating rod (205).

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