A resistance heated rotary hearth furnace

Abstract

This utility model relates to the technical field of heating furnaces, and in particular to a rotary hearth furnace with resistance heating, comprising: a furnace body, which is constructed into a ring structure through a masonry process; the outer wall of the furnace body is covered with a furnace top steel structure, which provides solid structural support for the furnace body and enhances the overall stability and strength of the furnace body; in this utility model, through a reasonable heat storage and heat release circulation mechanism, the waste heat generated during the resistance heating process can be effectively recovered, avoiding the waste caused by direct heat discharge, and greatly improving energy utilization efficiency; secondly, it also realizes a continuous and stable heating process, overcoming the temperature fluctuation problem caused by the start and stop of the resistance heating device compared with traditional heating methods, always maintaining a stable temperature inside the furnace, providing a uniform and continuous thermal environment for the materials, thereby significantly improving heating efficiency and stability.

Description

Technical Field

[0001] This utility model relates to the technical field of heating furnaces, and in particular to a rotary hearth furnace with resistance heating. Background Technology

[0002] In modern industrial production, resistance-heated rotary hearth furnaces are widely used in metallurgy, materials processing and other fields as an important heat processing equipment. Their working principle is based on the resistance heating effect, which converts electrical energy into heat energy to heat the materials.

[0003] Application No. 202420162888.8 discloses a resistance-heated rotary hearth furnace, including a rotating furnace bottom and a fixed furnace wall. The furnace wall is covered with a furnace roof steel structure. The furnace bottom, furnace wall, and furnace roof steel structure constitute the furnace body. The furnace bottom and furnace wall enclose a sealed furnace chamber space. The circumferential seam between the furnace wall and the furnace bottom is sealed with a water seal device, which is prior art and will not be described in detail here. Several resistance heating devices are provided in the furnace chamber space to heat the material on the furnace bottom. Combustion air nozzles are provided on the furnace wall to provide combustion air to the furnace chamber space. A furnace bottom mechanical rotation device is provided at the bottom of the furnace bottom to drive the furnace bottom to rotate. By replacing the original burner heating method with resistance heating devices, stable operation of the furnace atmosphere and temperature is achieved, which will not affect the chemical reaction process in the furnace, effectively reducing the amount of flue gas and dust emissions in the furnace and reducing environmental pollution.

[0004] However, a large amount of waste heat is inevitably generated during the resistance heating process. This waste heat is generally dissipated into the environment through furnace heat dissipation and flue gas exhaust. The large amount of heat contained in this process is lost with the furnace heat dissipation and flue gas exhaust and cannot be reused, resulting in a huge waste of energy. Secondly, when new materials are introduced or the temperature inside the furnace drops, the temperature can only be raised from zero by the resistance heating device. Due to the lack of waste heat assistance, more electrical energy is required to reach the temperature required by the process. This is especially true for materials with high temperature requirements and long processing times, which increases energy consumption. In addition, the temperature inside the furnace is difficult to reach a stable state quickly during the opening and closing of the resistance heating device. When heating is started, it takes a certain amount of time for the temperature inside the furnace to rise, while when it is closed, the temperature drops rapidly, resulting in significant fluctuations in the temperature inside the furnace. This makes it difficult to meet the process requirements for high temperature stability and affects the quality of material processing. Utility Model Content

[0005] The purpose of this invention is to provide a rotary hearth furnace with resistance heating to solve the problems mentioned in the background art.

[0006] The technical solution adopted in this utility model is:

[0007] A rotary hearth furnace with resistance heating, comprising:

[0008] The furnace body is constructed into a ring structure through a masonry process. The outer wall of the furnace body is covered with a furnace top steel structure, which provides solid structural support for the furnace body and enhances the overall stability and strength of the furnace body.

[0009] A material tray, located inside the furnace body, is used to hold the material to be heated.

[0010] A resistance heating element is installed inside the furnace body and located at the top of the material tray. It is used to radiate heat evenly to the material on the material tray, so that the material is fully and evenly heated in the furnace.

[0011] The heat storage heating structure is located on the outside of the furnace body. It is used to recover the waste heat generated during the resistance heating process and to achieve efficient energy utilization and continuous and stable heating by utilizing the heat storage and heat release cycle mechanism.

[0012] Optionally, the heat storage heating structure includes:

[0013] The first heat storage tank is located on one side of the exterior of the furnace body;

[0014] The second heat storage tank is located on the other side of the outside of the furnace body;

[0015] Two heat inlet pipes are respectively connected to the upper end face of the first heat storage tank and the second heat storage tank. Each of the two heat inlet pipes is equipped with a switch valve, and the air inlet end of the two heat inlet pipes passes through the furnace top steel structure and the furnace body and extends into the interior of the furnace body.

[0016] Two discharge pipes are respectively connected to the outer walls of the first heat storage tank and the second heat storage tank. Each of the two discharge pipes is equipped with a switch valve, and the outlet ends of the two discharge pipes extend through and into the interior of the furnace body.

[0017] Two honeycomb ceramic heat storage elements are respectively connected to the inner walls of the first heat storage tank and the second heat storage tank;

[0018] Two supporting grids are fixedly connected to the inside of the first heat storage tank and the second heat storage tank, respectively, and the supporting grids are located at the lower end of the honeycomb ceramic heat storage body;

[0019] Two support bases are respectively connected to the lower outer walls of the first and second heat storage tanks to provide stable support for the heat storage tanks.

[0020] Optionally, the heat storage heating structure further includes:

[0021] Two sets of vertical rods are fixedly connected to the inner walls of the first heat storage tank and the second heat storage tank, respectively, and each set of vertical rods is located at the upper and lower ends of the honeycomb ceramic heat storage body;

[0022] Two sets of spiral blocks are respectively fixedly connected to the two sets of vertical rods.

[0023] Optionally, the inner surface of the furnace body is provided with a heat insulation component, the heat insulation component comprising:

[0024] A sealing and protective layer is provided on the inner surface wall of the furnace body, and the material of the sealing and protective layer is aluminum silicate.

[0025] A heat-insulating intermediate layer is disposed inside the sealing protective layer, and the heat-insulating intermediate layer is made of rock wool.

[0026] The high-temperature resistant inner side is located on the inner side of the heat insulation intermediate layer, and the material of the high-temperature resistant inner side is ceramic fiber material.

[0027] Optionally, the lower end of the material tray is symmetrically connected to two supporting side plates, the lower ends of the two supporting side plates are connected to a placement base, a feeding hopper is connected to one side of the upper end of the furnace body, and a combustion air nozzle is connected to the outer wall of the furnace body.

[0028] Optionally, an installation plate is fixedly connected to the inner surface of the furnace body and located at the upper end of the material tray, and the resistance heating element is installed on the lower end face of the installation plate.

[0029] Optionally, the placement base is provided with a rotating assembly for rotating the material tray, the rotating assembly including:

[0030] The drive motor is installed in a pre-reserved slot inside the placement base;

[0031] A drive rod is connected to the output end of the drive motor;

[0032] The connecting horizontal plate is fixedly connected between the two supporting side plates.

[0033] Optionally, the rotating assembly further includes:

[0034] The gear is fixedly connected to the outer wall of the drive rod;

[0035] Multiple tooth blocks are equidistantly and evenly connected to the inner surface of the connecting horizontal plate with pre-reserved through holes, and the multiple tooth blocks mesh with the gear.

[0036] Compared with the prior art, the beneficial effects of this utility model are:

[0037] By installing two heat storage tanks on the outside of the heating furnace, when the resistance heating element is turned on, the first heat storage tank is in a heat storage state during the resistance heating stage, storing heat through the heat inlet pipe. The honeycomb ceramic heat storage body inside the first heat storage tank absorbs and stores a large amount of heat due to its high specific surface area and good heat storage performance. The second heat storage tank is in a heat release state, releasing heat into the furnace through the discharge pipe to heat the materials. When the first heat storage tank has completed heat storage and the second heat storage tank has released all its heat, by closing and opening the corresponding pipes, the first heat storage tank begins to release heat, and the second heat storage tank switches to heat storage. This cycle repeats continuously, achieving continuous and stable heating. In this utility model, a reasonable heat storage and heat release cycle is achieved. This mechanism effectively recovers the waste heat generated during resistance heating, avoiding the waste caused by direct heat discharge and greatly improving energy efficiency. Secondly, it also achieves a continuous and stable heating process. Compared with traditional heating methods, it overcomes the temperature fluctuation problem caused by the start and stop of the resistance heating device, always maintaining a stable temperature inside the furnace and providing a uniform and continuous thermal environment for the materials, thereby significantly improving heating efficiency and stability. Moreover, by reducing the working time of the resistance heating device, its energy consumption is reduced, which in turn extends the service life of the resistance heating device, reduces equipment maintenance costs and replacement frequency, and makes the entire heating system more efficient, energy-saving and reliable. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the overall structure in this application;

[0040] Figure 2 This is a cross-sectional diagram of the present application;

[0041] Figure 3 This is an enlarged schematic diagram showing the connection of the furnace body, furnace top steel structure and insulation components in this application;

[0042] Figure 4 This is a schematic diagram showing the disassembled thermal insulation component in this application;

[0043] Figure 5 This is a cross-sectional view of the base placement in this application;

[0044] Figure 6 This is an enlarged schematic diagram of the rotating component in this application.

[0045] Figure label:

[0046] 1. Base; 2. Supporting side plates; 3. Material tray; 4. Furnace body; 5. Furnace roof steel structure; 6. Feed hopper;

[0047] 7. Heat storage and heating structure; 71. First heat storage tank; 72. Second heat storage tank; 73. Heat inlet pipe; 74. Discharge pipe; 75. Honeycomb ceramic heat storage body; 76. Support grid; 77. Bearing seat; 711. Vertical rod; 712. Spiral block;

[0048] 8. Combustion air nozzle;

[0049] 9. Thermal insulation components; 91. High-temperature resistant inner layer; 92. Thermal insulation intermediate layer; 93. Sealing and protective layer;

[0050] 10. Mounting plate; 11. Resistance heating element;

[0051] 12. Rotating assembly; 121. Drive motor; 122. Drive rod; 123. Gear; 124. Connecting cross plate; 125. Gear block. Detailed Implementation

[0052] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] Given that in the current technology, a large amount of waste heat will inevitably be generated during the resistance heating process, this waste heat is generally lost to the environment through furnace heat dissipation and smoke exhaust. The large amount of heat contained therein is lost with the furnace heat dissipation and smoke exhaust and cannot be reused, thus causing a huge waste of energy.

[0055] like Figure 1 and Figure 2 As shown, this utility model embodiment provides a rotary hearth furnace with resistance heating, including a furnace body 4, a material tray 3 and a resistance heating element 11.

[0056] The furnace body 4 is constructed into a ring structure using a masonry process. The outer wall of the furnace body 4 is covered with a furnace top steel structure 5, which provides solid structural support for the furnace body 4, enhancing its overall stability and strength. A material tray 3 is located inside the furnace body 4 to hold the material to be heated. Two supporting side plates 2 are symmetrically connected to the lower end of the material tray 3, and a base 1 is connected to the lower end of the two supporting side plates 2. A feeding hopper 6 is connected to one side of the upper end of the furnace body 4, and a combustion air nozzle 8 is connected to the outer wall of the furnace body 4. (The last sentence appears to be incomplete and possibly refers to a different furnace body.) The heating element 11 is located inside the furnace body 4 and above the material tray 3. It is used to radiate heat evenly to the material on the material tray 3, so that the material is fully and evenly heated in the furnace. The inner wall of the furnace body 4 and above the material tray 3 is fixedly connected to the mounting plate 10. The resistance heating element 11 is installed on the lower end of the mounting plate 10. (The resistance heating element 11 consists of a connector and an iron-chromium-aluminum alloy resistance wire. The connector consists of two blocks and a cylinder. The cylinder is fixedly connected between the two blocks. The iron-chromium-aluminum alloy resistance wire is wound around the outside of the cylinder.)

[0057] Further, see Figure 5 and Figure 6 As shown, the base 1 is provided with a rotating assembly 12 for rotating the tray 3. The rotating assembly 12 includes a drive motor 121, a drive rod 122, a connecting horizontal plate 124, a gear 123, and multiple toothed blocks 125. The drive motor 121 is installed in a pre-reserved slot inside the base 1. The drive rod 122 is connected to the output end of the drive motor 121. The connecting horizontal plate 124 is fixedly connected between two support side plates 2. The gear 123 is fixedly connected to the outer wall of the drive rod 122. Multiple toothed blocks 125 are equidistantly and evenly connected to the inner wall of the connecting horizontal plate 124 with a pre-reserved through hole. The multiple toothed blocks 125 mesh with the gear 123.

[0058] In use, the material is first fed onto the material tray 3 through the feed hopper 6. At this time, the drive motor 121 (model: Z4-112 / 4-1) drives the drive rod 122 to rotate, which in turn drives the gear 123 to rotate. At the same time, the gear 123 meshes with the tooth block 125, so that the material tray 3 connected by the support side plate 2 rotates. Then, the rotary hearth furnace is powered on. When the current passes through the iron-chromium-aluminum alloy resistance wire in the resistance heating device, the iron-chromium-aluminum alloy resistance wire heats up and converts electrical energy into heat energy. The heat is transferred to the material through radiation and convection, thereby heating the material on the material tray 3. In addition, the rotation of the material tray 3 allows the material to move slowly in the furnace and pass through different temperature zones in sequence to achieve uniform heating or complete a specific process.

[0059] Furthermore, in order to efficiently recover and recycle the waste heat generated during the resistance heating process, the heating furnace also includes a heat storage heating structure 7.

[0060] Specifically, such as Figure 1 and Figure 2 As shown, the heat storage heating structure 7 is located on the outside of the furnace body 4. It is used to recover the waste heat generated during the resistance heating process and to achieve efficient energy utilization and continuous and stable heating by utilizing the heat storage and heat release cycle mechanism.

[0061] The heat storage heating structure 7 includes a first heat storage tank 71, a second heat storage tank 72, two heat inlet pipes 73, two exhaust pipes 74, two honeycomb ceramic heat storage bodies 75, two supporting grids 76, and two bearing seats 77. The first heat storage tank 71 is located on one side of the furnace body 4, and the second heat storage tank 72 is located on the other side of the furnace body 4. The two heat inlet pipes 73 are respectively connected to the upper end faces of the first heat storage tank 71 and the second heat storage tank 72. Each of the two heat inlet pipes 73 is equipped with a switch valve, and the air inlet ends of the two heat inlet pipes 73 penetrate the furnace top steel structure 5 and the furnace body 4 and extend into the interior of the furnace body 4. The two exhaust pipes 74 are respectively... Two discharge pipes 74 are connected to the outer walls of the first heat storage tank 71 and the second heat storage tank 72. Each discharge pipe 74 is equipped with a switch valve, and the outlet of each discharge pipe 74 extends through and into the interior of the furnace body 4. Two honeycomb ceramic heat storage bodies 75 are connected to the inner walls of the first heat storage tank 71 and the second heat storage tank 72, respectively. Two support grids 76 are fixedly connected to the interior of the first heat storage tank 71 and the second heat storage tank 72, respectively. The support grids 76 are located at the lower end of the honeycomb ceramic heat storage bodies 75. Two bearing seats 77 are connected to the lower outer walls of the first heat storage tank 71 and the second heat storage tank 72, respectively, for the purpose of stabilizing and supporting the heat storage tanks.

[0062] Furthermore, the heat storage heating structure 7 also includes two sets of vertical rods 711 and two sets of spiral blocks 712. The two sets of vertical rods 711 are respectively fixedly connected to the inner surface of the first heat storage tank 71 and the second heat storage tank 72. Each set of vertical rods 711 is located at the upper and lower ends of the honeycomb ceramic heat storage body 75, and the two sets of spiral blocks 712 are respectively fixedly connected to the two sets of vertical rods 711.

[0063] When the resistance heating element is turned on, the first heat storage tank 71 is in a heat storage state during the resistance heating stage, storing heat through the heat inlet pipe 73. The honeycomb ceramic heat storage body 75 inside the first heat storage tank 71 absorbs and stores a large amount of heat due to its high specific surface area and good heat storage performance. The second heat storage tank 72 is in a heat release state, releasing heat into the furnace through the discharge pipe 74 to heat the materials. When the first heat storage tank 71 has completed heat storage and the second heat storage tank 72 has exhausted its heat, by closing and opening the corresponding pipes, the first heat storage tank 71 begins to release heat, and the second heat storage tank 72 switches to heat storage. This cycle repeats continuously, achieving continuous and stable heating. Through a reasonable heat storage and heat release cycle mechanism, the waste heat generated during the resistance heating process can be effectively recovered, avoiding… This eliminates the waste caused by direct heat discharge, greatly improving energy efficiency. Secondly, it achieves a continuous and stable heating process, overcoming temperature fluctuations caused by the start-up and shutdown of the device in traditional heating, maintaining a stable furnace temperature, optimizing the material heating environment, and improving heating efficiency. It also reduces the working time and energy consumption of the resistance heating device, extends its service life, and reduces equipment maintenance and replacement costs, making the heating system more efficient and energy-saving. In addition, the spiral shape of the spiral block 712 can change the heat flow path and guide it to flow in a spiral shape, promoting the uniform penetration of heat flow into the honeycomb ceramic heat storage body 75, avoiding local heat accumulation or uneven heat storage, thereby significantly improving the heat storage and heat release efficiency of the heat storage tank and optimizing the waste heat recovery and heating performance of the entire rotary hearth furnace.

[0064] Specifically, such as Figure 2 and Figure 3 As shown, the inner wall of the furnace body 4 is provided with a heat insulation component 9.

[0065] The insulation component 9 includes a sealing protective layer 93, a heat insulation intermediate layer 92, and a high-temperature resistant inner layer 91. The sealing protective layer 93 is located on the inner wall of the furnace body 4 and is made of aluminum silicate. The heat insulation intermediate layer 92 is located inside the sealing protective layer 93 and is made of rock wool. The high-temperature resistant inner layer 91 is located inside the heat insulation intermediate layer 92 and is made of ceramic fiber.

[0066] In use, the insulation component 9 adopts a multi-layer composite structure, with each layer of material working together. The high-temperature resistant inner layer 91 is made of ceramic fiber, which not only has excellent high-temperature resistance and can withstand the high-temperature environment inside the rotary hearth furnace, but also has low thermal conductivity, which can effectively block heat from being conducted into the insulation board. At the same time, its good chemical stability makes it less susceptible to corrosion by high-temperature gases and materials inside the furnace. The heat insulation middle layer 92 is made of rock wool, which further prevents heat transmission while playing a sound absorption and noise reduction role, reducing the operating noise of the rotary hearth furnace. The non-combustible properties of rock wool also improve the fire safety of the insulation board. The sealing protective layer 93 is made of aluminum silicate material, which can prevent outside air from entering the furnace and reduce heat loss caused by air convection. Its flexibility and impact resistance can protect the internal insulation material from external physical damage, while also having good high-temperature resistance, not easily deformed or aged at high temperatures, and can play a long-term protective role.

[0067] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A rotary hearth furnace with resistance heating, characterized in that, include: The furnace body is constructed into a ring structure through a masonry process. The outer wall of the furnace body is covered with a furnace top steel structure, which provides solid structural support for the furnace body and enhances the overall stability and strength of the furnace body. A material tray, located inside the furnace body, is used to hold the material to be heated. A resistance heating element is installed inside the furnace body and located at the top of the material tray. It is used to radiate heat evenly to the material on the material tray, so that the material is fully and evenly heated in the furnace. The heat storage heating structure is located on the outside of the furnace body. It is used to recover the waste heat generated during the resistance heating process and to achieve efficient energy utilization and continuous and stable heating by utilizing the heat storage and heat release cycle mechanism.

2. The rotary hearth furnace with resistance heating according to claim 1, characterized in that, The heat storage and heating structure includes: The first heat storage tank is located on one side of the exterior of the furnace body; The second heat storage tank is located on the other side of the outside of the furnace body; Two heat inlet pipes are respectively connected to the upper end face of the first heat storage tank and the second heat storage tank. Each of the two heat inlet pipes is equipped with a switch valve, and the air inlet end of the two heat inlet pipes passes through the furnace top steel structure and the furnace body and extends into the interior of the furnace body. Two discharge pipes are respectively connected to the outer walls of the first heat storage tank and the second heat storage tank. Each of the two discharge pipes is equipped with a switch valve, and the outlet ends of the two discharge pipes extend through and into the interior of the furnace body. Two honeycomb ceramic heat storage elements are respectively connected to the inner surface walls of the first heat storage tank and the second heat storage tank; Two supporting grids are fixedly connected to the inside of the first heat storage tank and the second heat storage tank, respectively, and the supporting grids are located at the lower end of the honeycomb ceramic heat storage body; Two support bases are respectively connected to the lower outer walls of the first and second heat storage tanks to provide stable support for the heat storage tanks.

3. A rotary hearth furnace with resistance heating according to claim 2, characterized in that, The heat storage heating structure also includes: Two sets of vertical rods are fixedly connected to the inner walls of the first heat storage tank and the second heat storage tank, respectively, and each set of vertical rods is located at the upper and lower ends of the honeycomb ceramic heat storage body; Two sets of spiral blocks are respectively fixedly connected to the two sets of vertical rods.

4. A rotary hearth furnace with resistance heating according to claim 1, characterized in that, The inner surface of the furnace body is provided with a heat insulation component, which includes: A sealing and protective layer is provided on the inner surface wall of the furnace body, and the material of the sealing and protective layer is aluminum silicate. A heat-insulating intermediate layer is disposed inside the sealing protective layer, and the heat-insulating intermediate layer is made of rock wool. The high-temperature resistant inner side is located on the inner side of the heat insulation intermediate layer, and the material of the high-temperature resistant inner side is ceramic fiber material.

5. A rotary hearth furnace with resistance heating according to claim 1, characterized in that, The lower end of the material tray is symmetrically connected to two supporting side plates, and the lower ends of the two supporting side plates are connected to a placement base. A feeding hopper is connected to one side of the upper end of the furnace body, and an auxiliary combustion air nozzle is connected to the outer wall of the furnace body.

6. A rotary hearth furnace with resistance heating according to claim 1, characterized in that, An installation plate is fixedly connected to the inner surface of the furnace body and to the upper end of the material tray, and the resistance heating element is installed on the lower end face of the installation plate.

7. A rotary hearth furnace with resistance heating according to claim 5, characterized in that, The placement base is equipped with a rotating assembly for rotating the material tray, the rotating assembly comprising: The drive motor is installed in a pre-reserved slot inside the placement base; A drive rod is connected to the output end of the drive motor; The connecting horizontal plate is fixedly connected between the two supporting side plates.

8. A rotary hearth furnace with resistance heating according to claim 7, characterized in that, The rotating assembly also includes: The gear is fixedly connected to the outer wall of the drive rod; Multiple tooth blocks are equidistantly and evenly connected to the inner surface of the connecting horizontal plate with pre-reserved through holes, and the multiple tooth blocks mesh with the gear.

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