Sintering furnace

Abstract

A sintering furnace comprises a furnace body. The furnace lining is mounted on the inner surface of the furnace body; the heating resistance wires are uniformly arranged on the surface of the furnace lining; the furnace inner barrels are located in the furnace body and surrounded by the heating resistance wires, and communicating cavities are formed between the upper furnace inner barrel and the lower furnace inner barrel which are adjacent to each other; the central heating component is positioned in the center of the furnace inner barrel; and the exhaust pipe is fixedly mounted on the upper surface of the furnace body and extends into the furnace body. The central heating component comprises a central heating column, and the bottom of the central heating column and the bottom surface of the furnace inner cylinder are fixedly arranged. Through the dual heating mode of the central heating component and the furnace lining surface heating resistance wire, internal and external synchronous heating is achieved, the temperature difference is reduced, the device is especially suitable for materials with poor heat conductivity, and production efficiency is improved. The heating resistance wire on the surface of the furnace lining provides peripheral radiant heat, the central heating column generates a central heat source through resistance heating, internal and external synergistic heating is formed, and the sintering efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of furnace technology, specifically a sintering furnace. Background Technology

[0002] Sintering, the process of transforming powdered materials into a dense body, is a traditional technology. It has long been used to produce ceramics, powder metallurgy, refractories, and ultra-high temperature materials. Generally, after powder is shaped, the resulting dense body through sintering is a polycrystalline material whose microstructure consists of crystals, glassy components, and pores. The sintering process directly affects the grain size, pore size, and grain boundary shape and distribution within the microstructure, thus influencing the material's properties.

[0003] A sintering furnace is a specialized piece of equipment that enables powder compacts to obtain the required physical and mechanical properties and microstructures through sintering. Most existing sintering furnaces have heating rods around the product. During the heating process, temperature differences can easily occur between the inside and outside of the sintering furnace, causing uneven heating of the product and affecting the sintering results. For some products with poor thermal conductivity, the heating time is longer, and the temperature difference between the inside and outside of the sintering furnace can more easily affect the sintering results of the product, thus affecting the overall production efficiency.

[0004] A search revealed that invention CN107270714B discloses a sintering furnace, comprising a furnace body, a furnace lining installed on the inner surface of the furnace body, resistance wires installed on the furnace lining, and an inner cylinder installed inside the furnace body, the inner cylinder being surrounded by the resistance wires. The inner cylinder consists of a connecting pipe, an inner cylinder cover, a temperature measuring sleeve, an exhaust port, an inner sleeve, an inner cylinder body, and a heating element. The inner sleeve is installed inside the inner cylinder, and the heating element is installed at the center of the inner sleeve. The connecting pipe connects the inner cylinder body and the inner sleeve. The inner cylinder cover of the inner cylinder body is welded with a temperature measuring sleeve and an exhaust port. This invention heats both the inside and outside of the furnace simultaneously by setting a heating column in the center of the furnace body, but the internal space of the furnace body is further compressed, and the circulation speed of the gas inside the furnace is further reduced. For products with poor thermal conductivity, uneven heating still exists. Summary of the Invention

[0005] In order to solve the problem of uneven heating of products during the sintering process in existing sintering furnaces, this utility model proposes a sintering furnace to solve the above problems.

[0006] A sintering furnace, comprising a furnace body;

[0007] Furnace lining, the furnace lining being installed on the inner surface of the furnace body;

[0008] Heating resistance wires are uniformly arranged on the surface of the furnace lining.

[0009] The furnace inner cylinder is located inside the furnace body and is surrounded by the heating resistance wire, and a connecting cavity is formed between the upper and lower adjacent furnace inner cylinders;

[0010] A central heating element, which is located at the center of the furnace inner cylinder;

[0011] An exhaust pipe is fixedly installed on the upper surface of the furnace body and extends into the interior of the furnace body.

[0012] Furthermore, the central heating component includes a central heating column, the bottom of which is fixedly disposed on the bottom surface of the furnace inner cylinder.

[0013] Furthermore, because a fixing device needs to be installed at the bottom of the central heating column, the heating resistor inside the central heating column is a certain distance from the bottom when heating, resulting in a temperature difference between the top and bottom of the central heating column. This creates a temperature difference between the bottom and top of the furnace, causing uneven heating of the furnace cylinder at the bottom and affecting the sintering of the product.

[0014] Furthermore, by employing a dual heating method—combining a central heating element with heating resistance wires on the furnace lining surface—heating is achieved simultaneously from the inside out, reducing temperature differences. This method is particularly suitable for materials with poor thermal conductivity, thereby improving production efficiency.

[0015] Furthermore, the heating resistance wires on the furnace lining surface provide peripheral radiant heat, while the central heating column generates a central heat source through resistance heating, forming a coordinated heating effect between the inside and outside.

[0016] Furthermore, the gas enters the gas acceleration channel through the inlet hole, and after being accelerated by the rotation of the spiral guide vanes, it is evenly diffused to the surrounding area of ​​the furnace cylinder by the umbrella-shaped diffuser; the Venturi tube structure further accelerates the gas flow through the contraction-expansion effect, promoting uniform heat distribution.

[0017] Furthermore, the nested structure of the inner furnace cylinder and the central heating column maximizes the use of the furnace space, while the gas circulation and heating functions are integrated through the connecting cavity.

[0018] Furthermore, a sleeve is fitted onto the outer surface of the central heating column, forming a gas acceleration channel between the sleeve and the central heating column. Spiral guide vanes are uniformly arranged on the inner surface of the gas acceleration channel. An umbrella-shaped diffuser is installed at the top of the central heating column. An air inlet is opened on the bottom surface of the sleeve, uniformly arranged along the circumference of the sleeve and tilted. The spiral guide vanes and umbrella-shaped diffuser optimize airflow distribution, force gas rotation and diffusion, and enhance heat exchange uniformity. The connecting cavity and the gas acceleration channel form a directional airflow path, accelerating heat conduction and improving sintering efficiency.

[0019] Furthermore, the spiral guide vane is divided into a bottom coarse guide layer, a middle transition layer, and a top fine guide layer;

[0020] The bottom coarse guide layer uses a large-pitch spiral to convert the horizontal circulation into vertical upward motion, generating an initial rotating flow field;

[0021] The middle transition layer uses a head-leading spiral to cut the coarse flow into multiple fine flows, which in turn generate microscale turbulence by passing through guide vanes, thus accelerating gas flow.

[0022] The top fine guide layer uses a small-lead spiral to evenly diffuse the rotational kinetic energy to the edge of the furnace, driving the edge gas to flow faster, while simultaneously turning downwards to accelerate circulation.

[0023] Furthermore, the inner spiral guide vanes force the gas to form a swirling flow, which, combined with the diffusion effect of the umbrella-shaped diffuser, evenly covers the heated airflow onto the surface of the furnace cylinder; the Venturi tube structure formed by adjacent protrusions accelerates the airflow through cross-sectional contraction, and then reduces the flow velocity and enhances turbulence through the expansion section, further breaking the thermal boundary layer and improving heat transfer efficiency.

[0024] Furthermore, the connecting cavity between adjacent upper and lower furnace cylinders forms a vertical airflow channel, avoiding local airflow stagnation and ensuring that heat is evenly distributed in the three-dimensional space inside the furnace.

[0025] Furthermore, a protrusion is installed on the surface of the furnace lining at a position corresponding to the position of the inner furnace cylinder. A protrusion is also provided on the surface of the inner furnace cylinder near the furnace lining. Adjacent protrusions cooperate to form a Venturi tube structure. The distance between adjacent protrusions gradually decreases from top to bottom, forming a pressure difference.

[0026] Furthermore, through the dual heating method of the central heating component and the heating resistance wire on the furnace lining surface, the internal and external heating are synchronized. Combined with the gas acceleration channel and Venturi tube structure, the gas circulation efficiency inside the furnace is significantly improved, and the temperature difference is reduced, which is especially suitable for materials with poor thermal conductivity.

[0027] Furthermore, a vacuum insulation layer is provided between the furnace body and the furnace lining, and the side of the vacuum insulation layer closest to the furnace body is covered with radiation shielding foil; the vacuum insulation layer and radiation shielding foil greatly reduce heat loss; the S-shaped arrangement of the circulating water pipes and the design of the flow stabilizing cavity ensure efficient cooling and maintain the temperature stability of the furnace body.

[0028] Furthermore, a water channel layer is provided inside the furnace body on the side away from the furnace lining, and a circulating water pipe is provided in the water channel layer. The circulating water pipe is arranged in an S-shape from top to bottom. A water inlet is provided on the surface of the furnace body, and a water outlet is provided on the lower surface of the bottom of the furnace body.

[0029] Furthermore, a flow stabilizing cavity is provided at the connection between the water outlet and the circulating water pipe. The diameter of the flow stabilizing cavity is a multiple of the diameter of the circulating water pipe, and a flow guide plate is fixedly installed inside the flow stabilizing cavity.

[0030] Furthermore, a temperature measuring sleeve is installed on the surface of the furnace body; the integrated design of the inner cylinder and the central heating column realizes multiple heating and airflow control functions in a limited space, further improving sintering efficiency. The temperature measuring sleeve installed on the surface of the furnace body can monitor the temperature inside the furnace at multiple points, and combined with the control system, dynamically adjust the heating power and cooling water flow to achieve precise temperature control.

[0031] Furthermore, when the sintering furnace is working, the heating system works in synergy, with peripheral heating and central heating occurring simultaneously; peripheral heating: the heating resistance wires on the surface of the furnace lining generate high-temperature radiant heat after being energized, which directly acts on the outer wall of the inner cylinder of the furnace.

[0032] Central heating: The central heating column generates high temperature through resistance heating. The heat is transferred to the central area of ​​the furnace cylinder through the airflow in the gas acceleration channel. At the same time, the umbrella-shaped diffuser spreads the hot airflow to the surrounding areas and covers the surface of the material.

[0033] While being heated, the gas enters the gas acceleration channel through the inclined air inlet, forming a high-speed swirling flow under the guidance of the spiral guide vanes. The swirling gas is heated to the target temperature by the central heating column within the channel.

[0034] After passing through the umbrella-shaped diffuser, the flow velocity of the hot air decreases but the coverage area expands, and it is evenly distributed around the furnace cylinder; the venturi tube structure protrusions further accelerate the airflow through cross-sectional contraction, enhancing the convective heat transfer efficiency.

[0035] The airflow forms a vertical circulation path between the upper and lower furnace inner cylinders through the connecting cavity, avoiding heat accumulation in the horizontal direction and achieving three-dimensional uniform heating.

[0036] Furthermore, the S-shaped water path design of the circulating water pipe extends the contact time between the cooling water and the furnace body. The flow stabilizing cavity reduces the water flow velocity by expanding the cross-section, and the guide vanes eliminate eddies, ensuring that the cooling water stably absorbs heat and preventing the shell from overheating.

[0037] Furthermore, the vacuum insulation layer blocks external heat loss, and the temperature measuring sleeve collects furnace temperature data in real time, feeding it back to the control system to adjust the heating power and cooling water flow rate, maintaining the furnace temperature fluctuation range.

[0038] The working principle utilizes natural convection driven by temperature difference, leveraging the buoyancy effect. The core driving force of gas circulation comes from the density difference caused by heating. According to Archimedes' principle of buoyancy, the density of heated gas decreases, creating upward buoyancy in the gravitational field, resulting in natural convection. Simultaneously, heat spontaneously transfers from the high-temperature zone to the low-temperature zone, driving gas flow. During the heating phase, the central heating column and peripheral resistance wires activate, raising the gas temperature around the inner cylinder of the furnace, forming a high-temperature zone. The density of the high-temperature gas decreases, and under the action of buoyancy, it rises along the gas acceleration channel. The high-temperature gas diffuses to the edge of the inner cylinder through the umbrella-shaped diffuser, absorbing some heat upon contact with the material, causing its temperature to drop. The density of the cooled gas increases, and it sinks through the connecting cavity between the upper and lower inner cylinders, forming a vertical circulation loop; at the same time, the geometric structure further amplifies the buoyancy effect.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. Uniform heating and efficient heat conduction:

[0041] Dual heat source synergistic heating: the outer heating resistance wire heats the furnace cylinder externally through radiation, while the central heating component provides heat directly to the central area of ​​the furnace through the central heating column. The dual heating mode effectively reduces the temperature gradient inside the furnace.

[0042] Forced gas circulation design: The spiral guide vanes in the gas acceleration channel force the gas to form a swirling flow. Combined with the diffusion effect of the umbrella-shaped diffuser, the heated airflow is evenly covered to the surface of the furnace cylinder. The Venturi tube structure formed by adjacent protrusions accelerates the airflow through cross-sectional contraction, and then reduces the flow velocity and enhances turbulence through the expansion section, further breaking the thermal boundary layer and improving heat transfer efficiency.

[0043] Optimized airflow path through connecting cavities: Connecting cavities between adjacent upper and lower furnace cylinders form vertical airflow channels, avoiding local airflow stagnation and ensuring uniform heat distribution within the three-dimensional space of the furnace.

[0044] 2. Improve temperature stability: The vacuum insulation layer isolates the furnace body from the external environment, and the radiation shielding foil reduces heat loss by reflecting the heat radiation inside the furnace. The combination of the two significantly reduces energy consumption. The circulating water pipe adopts an S-shaped arrangement to extend the flow path of cooling water in the furnace body. With the help of the flow stabilizing cavity and internal guide vanes, water flow turbulence is eliminated, ensuring that the cooling water absorbs the heat of the furnace body evenly and avoiding local overheating that could cause the furnace body to deform.

[0045] 3. Compact structure: The nested structure of the inner furnace cylinder and the central heating column maximizes the use of the furnace space, while the gas circulation and heating functions are integrated through the connecting cavity. Attached Figure Description

[0046] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of a sintering furnace structure;

[0048] Figure 2 for Figure 1 Enlarged view of section A in the middle;

[0049] Figure 3 for Figure 1 Enlarged view of section B;

[0050] Figure 4 This is a cross-sectional view of the central heating component.

[0051] Figure 5 A three-dimensional structural diagram of the central heating component;

[0052] Figure 6 This is a three-dimensional structural diagram of the central heating column.

[0053] In the picture:

[0054] 1. Furnace body;

[0055] 2. Circulating water pipes;

[0056] 3. Furnace lining;

[0057] 4. Heating resistance wire;

[0058] 5. Furnace inner cylinder;

[0059] 6. Exhaust pipe;

[0060] 7. Water inlet interface;

[0061] 8. Central heating element;

[0062] 9. Protrusion;

[0063] 10. Umbrella-shaped diffuser;

[0064] 11. Central heating column; 1101. Heating column housing; 1102. Heating element; 1103. Support frame;

[0065] 12. Gas acceleration channel;

[0066] 13. Spiral guide vanes;

[0067] 14. Air intake;

[0068] 15. Water outlet;

[0069] 16. Vacuum insulation layer;

[0070] 17. Connecting cavity. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0072] The application principle of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0073] Example 1

[0074] like Figure 1-5 As shown: A sintering furnace, including a furnace body 1;

[0075] Furnace lining 3 is installed on the inner surface of the furnace body 1;

[0076] Heating resistance wire 4 is uniformly disposed on the surface of the furnace lining 3;

[0077] Furnace inner cylinder 5, which is located inside the furnace body 1 and is surrounded by the heating resistance wire 4, and a connecting cavity 17 is formed between the upper and lower adjacent furnace inner cylinders 5;

[0078] Central heating element 8, which is located at the center of the furnace inner cylinder 5;

[0079] Exhaust pipe 6 is fixedly installed on the upper surface of the furnace body 1 and extends into the interior of the furnace body 1.

[0080] The central heating component 8 includes a central heating column 11, the bottom of which is fixedly disposed on the bottom surface of the furnace inner cylinder 5.

[0081] The central heating column 11 includes a heating column housing 1101, a support frame 1103 is provided inside the heating column housing 1101, a fixing groove is provided on the surface of the support frame 1103, and an electric heating tube 1102 is installed in the fixing groove.

[0082] The dual heating method of central heating element 8 and surface heating resistance wire 4 of furnace lining 3 enables simultaneous internal and external heating, reducing temperature difference. It is especially suitable for materials with poor thermal conductivity and improves production efficiency.

[0083] The heating resistance wire 4 on the surface of the furnace lining 3 provides peripheral radiant heat, and the central heating column 11 generates a central heat source through resistance heating, forming a coordinated heating model inside and outside;

[0084] Gas enters the gas acceleration channel 12 through the inlet 14, and after being accelerated by the rotation of the spiral guide vane 13, it is evenly diffused to the area around the furnace cylinder 5 by the umbrella-shaped diffuser 10; the Venturi tube structure further accelerates the gas flow through the contraction-expansion effect, promoting uniform heat distribution.

[0085] The nested structure of the inner furnace cylinder 5 and the central heating column 11 maximizes the use of the furnace space, while the gas circulation and heating functions are integrated through the connecting cavity 17.

[0086] A sleeve is fitted on the outer surface of the central heating column 11, forming a gas acceleration channel 12 between the sleeve and the central heating column 11. Spiral guide vanes are uniformly arranged on the inner surface of the gas acceleration channel 12. An umbrella-shaped diffuser 10 is installed at the top of the central heating column 11. An air inlet 14 is opened on the bottom surface of the sleeve, and the air inlet 14 is uniformly arranged along the circumference of the sleeve and is inclined. The spiral guide vanes 13 and the umbrella-shaped diffuser 10 optimize the airflow distribution, force the gas to rotate and diffuse, and enhance the uniformity of heat exchange. The connecting cavity 17 and the gas acceleration channel 12 form a directional airflow path, accelerate heat conduction, and improve sintering efficiency.

[0087] The spiral guide vane 13 is divided into a bottom coarse guide layer, a middle transition layer and a top fine guide layer;

[0088] The bottom coarse guide layer uses a 3-head large-pitch spiral to convert the horizontal circulation into vertical upward motion, generating an initial rotating flow field;

[0089] The middle transition layer uses a 6-head medium-lead screw to cut the coarse flow into multiple fine flows, so that the fine flows pass through the guide vanes to generate micro-scale turbulence and accelerate the gas flow;

[0090] The top fine guide layer uses a 12-head small-lead spiral to evenly diffuse the rotational kinetic energy to the edge of the furnace, driving the edge gas to flow faster, while simultaneously turning downwards to accelerate circulation.

[0091] Furthermore, the inner spiral guide vane 13 forces the gas to form a swirling flow, which, combined with the diffusion effect of the umbrella-shaped diffuser 10, evenly covers the heated airflow onto the surface of the furnace inner cylinder 5; the Venturi tube structure formed by the adjacent protrusions 9 accelerates the airflow through cross-sectional contraction, and then reduces the flow velocity and enhances turbulence through the expansion section, further breaking the thermal boundary layer and improving the heat transfer efficiency.

[0092] The connecting cavity between the upper and lower adjacent furnace inner cylinders 5 forms a vertical airflow channel, which avoids local airflow stagnation and ensures that heat is evenly distributed in the three-dimensional space inside the furnace.

[0093] The furnace lining 3 has a protrusion 9 installed on its surface at a position corresponding to that of the furnace inner cylinder 5. The furnace inner cylinder 5 has a protrusion 9 on its surface near the furnace lining 3. Adjacent protrusions 9 cooperate to form a Venturi tube structure. The distance between adjacent protrusions 9 gradually decreases from top to bottom, forming a pressure difference.

[0094] Through the dual heating method of the central heating component 8 and the surface heating resistance wire 4 of the furnace lining 3, the internal and external heating is synchronized. Combined with the gas acceleration channel 12 and the Venturi tube structure, the gas circulation efficiency in the furnace is significantly improved and the temperature difference is reduced, which is especially suitable for materials with poor thermal conductivity.

[0095] Example 2

[0096] Based on Example 1, a sintering furnace is provided, wherein a vacuum insulation layer 16 is provided between the furnace body 1 and the furnace lining 3, and the side of the vacuum insulation layer 16 near the furnace body 1 is covered with radiation shielding foil; the vacuum insulation layer 16 and the radiation shielding foil greatly reduce heat loss; the S-shaped arrangement of the circulating water pipe 2 and the design of the flow stabilizing cavity ensure efficient cooling and maintain the temperature stability of the furnace body 1.

[0097] A water channel layer is provided inside the furnace body 1 on the side away from the furnace lining 3. A circulating water pipe 2 is provided in the water channel layer. The circulating water pipe 2 is arranged in an S-shape from top to bottom. A water inlet 7 is provided on the surface of the furnace body 1. A water outlet 15 is provided on the lower surface of the bottom of the furnace body 1.

[0098] A flow stabilizing cavity is provided at the connection between the water outlet 15 and the circulating water pipe 2. The diameter of the flow stabilizing cavity is three times the diameter of the circulating water pipe 2, and a flow guide plate is fixedly installed inside the flow stabilizing cavity.

[0099] A temperature measuring sleeve is installed on the surface of the furnace body 1; the integrated design of the inner cylinder 5 and the central heating column 11 enables multiple heating and airflow control functions within a limited space, further improving sintering efficiency. The temperature measuring sleeve installed on the surface of the furnace body 1 can monitor the furnace temperature at multiple points, and combined with the control system, dynamically adjust the heating power and cooling water flow to achieve precise temperature control.

[0100] When the sintering furnace is working, the heating system works in synergy, with peripheral heating and central heating occurring simultaneously. Peripheral heating: When the heating resistance wire 4 on the surface of the furnace lining 3 is energized, it generates high-temperature radiant heat, which directly acts on the outer wall of the inner cylinder 5 of the furnace, forming a high-temperature peripheral zone.

[0101] Central heating: The central heating column 11 generates high temperature through resistance heating. The heat is transferred to the central area of ​​the furnace cylinder 5 through the airflow in the gas acceleration channel 12. At the same time, the umbrella-shaped diffuser 10 diffuses the hot airflow to the surrounding areas and covers the surface of the material.

[0102] While being heated, the gas enters the gas acceleration channel 12 through the inclined air inlet 14, and forms a high-speed swirling flow under the guidance of the spiral guide vane 13. The swirling gas is heated to the target temperature by the central heating column 11 in the channel.

[0103] After passing through the umbrella-shaped diffuser 10, the flow velocity of the hot air decreases but the coverage area expands, and it is evenly distributed around the furnace inner cylinder 5; the Venturi tube structure protrusion 9 further accelerates the airflow through cross-sectional contraction, enhancing the convective heat transfer efficiency.

[0104] The airflow forms a vertical circulation path between the upper and lower furnace inner cylinders through the connecting cavity 17, avoiding heat accumulation in the horizontal direction and achieving three-dimensional uniform heating.

[0105] The S-shaped water path design of the circulating water pipe 2 extends the contact time between the cooling water and the furnace body 1. The flow stabilizing cavity reduces the water flow velocity by expanding the cross-section and eliminates eddies with the guide vanes, ensuring that the cooling water can stably absorb heat and preventing the shell from overheating.

[0106] The vacuum insulation layer 16 blocks external heat loss, and the temperature measuring sleeve collects the furnace temperature data in real time and feeds it back to the control system to adjust the heating power and cooling water flow rate to maintain the furnace temperature within a fluctuation range of ±5℃.

[0107] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0108] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A sintering furnace, characterized by: Furnace body (1); Furnace lining (3), the furnace lining (3) is installed on the inner surface of the furnace body (1); Heating resistance wire (4) is uniformly arranged on the surface of the furnace lining (3); The furnace inner cylinder (5) is located inside the furnace body (1) and is surrounded by the heating resistance wire (4). A connecting cavity (17) is formed between the upper and lower adjacent furnace inner cylinders (5). The central heating component (8) is located in the center of the furnace inner cylinder (5). The outer surface of the central heating column (11) is fitted with a sleeve, and the space between the sleeve and the central heating column (11) is a gas acceleration channel (12).

2. A sintering furnace according to claim 1, characterized in that: The central heating component (8) includes a central heating column (11), the bottom of which is fixedly disposed on the bottom surface of the furnace inner cylinder (5).

3. A sintering furnace according to claim 2, characterized in that: The gas acceleration channel (12) is uniformly provided with spiral guide vanes on its inner surface. The central heating column (11) is equipped with an umbrella-shaped diffuser (10) at its top. An air inlet (14) is provided on the bottom surface of the sleeve. The air inlet (14) is uniformly provided along the circumference of the sleeve and is inclined.

4. A sintering furnace according to claim 3, characterized in that: A protrusion (9) is installed on the surface of the furnace lining (3) at a position corresponding to the furnace inner cylinder (5). A protrusion (9) is provided on the surface of the furnace inner cylinder (5) near the furnace lining (3). Adjacent protrusions (9) cooperate to form a Venturi tube structure. The distance between adjacent protrusions (9) gradually decreases from top to bottom.

5. The sintering furnace of claim 1, wherein: A vacuum insulation layer (16) is provided between the furnace body (1) and the furnace lining (3), and the side of the vacuum insulation layer (16) closest to the furnace body (1) is covered with radiation shielding foil.

6. A sintering furnace according to claim 5, characterized in that: A water channel layer is provided inside the furnace body (1) on the side away from the furnace lining (3), and a circulating water pipe (2) is provided in the water channel layer.

7. A sintering furnace according to claim 6, characterized in that: The circulating water pipe (2) is arranged in an S-shape from top to bottom. The furnace body (1) is provided with a water inlet (7) on its surface and a water outlet (15) on its bottom surface.

8. A sintering furnace according to claim 7, characterized in that: A flow stabilizing cavity is provided at the connection between the water outlet (15) and the circulating water pipe (2). The diameter of the flow stabilizing cavity is three times the diameter of the circulating water pipe (2). A flow guide plate is fixedly installed inside the flow stabilizing cavity.

9. The sintering furnace of claim 1, wherein: A temperature measuring sleeve is installed on the surface of the furnace body (1).

10. The sintering furnace of claim 1, wherein: It also includes an exhaust pipe (6), which is fixedly installed on the upper surface of the furnace body (1) and extends into the interior of the furnace body (1).

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