A rotary kiln

Abstract

This application discloses a rotary kiln, comprising: a kiln body forming a processing space; a tray rotatably connected to the kiln body and disposed within the processing space for supporting the material to be processed; and a heating element disposed within the processing space for heating the processing space. The processing space is divided into at least a first heating zone and a second heating zone along the rotational circumference of the tray, and the first and second heating zones exhibit different temperature profiles during operation. Through the combination of circumferential partitioned heating and tray rotation circulation, the material repeatedly experiences low-temperature and high-temperature zones: in the low-temperature zone, the concentration difference drives volatile matter release, while in the high-temperature zone, residual components are decomposed and the surface atmosphere of the material is renewed. This cyclical effect enhances the mass transfer driving force each time the material returns to the low-temperature zone, effectively overcoming the problem of low efficiency in the later stages of traditional single-temperature zone coking, resulting in more complete coking and less residue, providing a high-quality precursor for subsequent sintering.

Description

Technical Field

[0001] This application relates to the field of kiln technology, and in particular to a rotary kiln. Background Technology

[0002] Sintering, a commonly used high-temperature heat treatment process, improves the structural strength and performance stability of products by promoting the diffusion, bonding, and densification of particles in powders or formed green bodies. For green bodies containing organic components such as organic binders, resins, and waxes, to avoid concentrated decomposition during subsequent high-temperature sintering, which could lead to blistering, cracking, or porosity defects, pretreatment by coking or pyrolysis is usually required before sintering. This treatment aims to gradually decompose and precipitate volatiles and organic components at lower temperatures, forming a relatively stable carbonized structure and providing a good precursor state for subsequent sintering.

[0003] The effectiveness of the coking process depends on the mass transfer driving force between the internal and external environments of the material: initially, due to the high concentration of volatiles inside and the low concentration outside, the concentration difference between the inside and outside is large, and volatiles are easy to discharge; however, as the process continues, the internal volatiles decrease and the pyrolysis products in the furnace accumulate, resulting in a decrease in the concentration difference and a decrease in the mass transfer driving force. Consequently, the coking efficiency decreases in the later stage, which in turn leads to a longer processing cycle, insufficient local coking, or volatile residues, affecting the final sintering quality. Summary of the Invention

[0004] This application provides a rotary kiln to solve the technical problem of insufficient coking due to decreased coking efficiency as processing progresses.

[0005] This application adopts the following technical solution: a rotary kiln, comprising: a kiln body forming a processing space; a tray rotatably connected to the kiln body and disposed within the processing space for supporting the material to be processed; and a heating element disposed within the processing space for heating the processing space; the processing space is divided into at least a first heating zone and a second heating zone in the circumferential direction of the tray's rotation, and the first heating zone and the second heating zone exhibit different temperature curves during operation.

[0006] According to one embodiment of this application, the furnace body includes a furnace body and a furnace bottom. The furnace bottom is vertically connected to the furnace body to enclose and form a processing space. A tray is placed on the furnace bottom and can move in and out of the processing space with the furnace bottom.

[0007] According to one embodiment of this application, the heating element is disposed in the furnace body and / or furnace bottom.

[0008] According to one embodiment of this application, a heating element is disposed on one side of the processing space in the circumferential direction, so that a first heating zone is formed on the side close to the heating element and a second heating zone is formed on the side away from the heating element, and the operating temperature of the first heating zone is higher than that of the second heating zone.

[0009] According to one embodiment of this application, heating elements are arranged circumferentially along the heating space, and multiple heating elements are configured to be independently controlled. In the first step of the initial processing stage, the working temperature of the first heating zone and the second heating zone is both the first temperature. In the subsequent second step, the temperature of the first heating zone is adjusted to the second temperature, which is higher than the first temperature.

[0010] According to one embodiment of this application, in the second step, the heating power of the multiple heating elements is distributed in a gradient along the circumferential rotation of the tray to form a temperature transition between the first heating zone and the second heating zone.

[0011] According to one embodiment of this application, the first temperature is 200℃-800℃, used to coke / pyrolyze the material to be processed; the second temperature is 1100℃-1700℃, used to sinter the material to be processed.

[0012] According to one embodiment of this application, the furnace body is further provided with an air inlet and an air outlet communicating with the processing space. The air inlet is located in the first heating zone and is used to introduce a protective atmosphere, while the air outlet is located in the second heating zone and is used to discharge the gas in the processing space.

[0013] According to one embodiment of this application, the tray is configured to rotate continuously or in steps so that the material to be processed repeatedly passes through the first heating zone and the second heating zone.

[0014] According to one embodiment of this application, the processing space is cylindrical, and the tray rotates about the central axis of the processing space.

[0015] Based on the above technical features, this application has at least the following technical effects: 1. By combining circumferential zone heating with tray rotation and circulation, the material repeatedly experiences low-temperature and high-temperature zones: in the low-temperature zone, the concentration difference drives volatilization and analysis, while in the high-temperature zone, residual components are decomposed and the surface atmosphere of the material is renewed. This cyclical effect enhances the mass transfer driving force each time it returns to the low-temperature zone, effectively overcoming the problem of low efficiency in the later stages of traditional single-temperature zone coking, resulting in more complete coking and less residue, providing a high-quality precursor for subsequent sintering.

[0016] 2. By using step-by-step temperature control, this application can complete the entire process of low-temperature coking, high-temperature coking, and even sintering sequentially within the same equipment, integrating the processes that originally required multiple equipment and multiple furnace loadings into one. This not only avoids the risks of cooling and contamination when materials are transferred between different equipment, but also significantly shortens the production cycle and reduces equipment investment and floor space requirements.

[0017] 3. By placing the air inlet in the low-temperature zone and the air outlet in the high-temperature zone, a directional flow atmosphere path is formed: the low-temperature zone continuously receives fresh atmosphere to maintain the concentration difference and promote the release of volatiles; the high-temperature zone promptly discharges pyrolysis products, preventing impurities from undergoing secondary reactions or deposition under sensitive high-temperature conditions. This atmosphere arrangement, in conjunction with zoned heating, further enhances the effect of the circulation process and ensures the consistency of the final product quality.

[0018] 4. The entire heat treatment process is completed inside a closed furnace. From the moment the material is loaded into the furnace until the end of the treatment, it remains in a controlled processing space without being exposed to the external environment. On the one hand, the furnace atmosphere can be precisely adjusted and maintained, avoiding oxidation, contamination, or secondary reactions caused by atmosphere fluctuations. On the other hand, the furnace's excellent thermal sealing, combined with circumferential zone heating and gradient temperature control, ensures a stable and uniform temperature field within the processing space. Every temperature curve experienced by the material during the rotational cycle is repeatable and predictable.

[0019] Other advantages, objectives and features of this application will be partly apparent from the description below, and partly understood by those skilled in the art through study and practice of this application. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is an overall schematic diagram of the rotary kiln provided in the embodiments of this application; Figure 2 This is a partial cross-sectional schematic diagram of the rotary kiln provided in the embodiments of this application.

[0022] Explanation of icon numbers: 10. Furnace body; 11. Processing space; 12. Furnace body; 13. Furnace bottom; 14. Insulation layer; 15. Shell; 20. Tray; 30. Heating element; 41. Lead screw; 42. Maintenance platform; 43. Inspection window; 44. Functional plug-in; 45. Functional port; 46. Air inlet; 47. Air outlet; 48. Motor. Detailed Implementation

[0023] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0024] Before introducing the embodiments of this application, the relevant technologies involved in this application will be introduced first.

[0025] Sintering is a common heat treatment process used in the processing of powder materials, shaped green bodies, or materials containing inorganic components. It improves the structural strength and performance stability of the product by promoting diffusion, bonding, and densification between particles at higher temperatures. In some materials, especially shaped green bodies containing organic binders, resins, waxes, or other organic additives, coking or pyrolysis treatment is usually required before sintering to prevent the organic components from decomposing and causing blistering, cracking, porosity defects, or uneven microstructure during the subsequent high-temperature sintering stage. The main function of coking is to gradually decompose, precipitate, and remove the volatiles and organic components in the material at relatively low temperatures, while simultaneously transforming some organic residues into a relatively stable carbonized structure, thus providing a more stable precursor state for subsequent sintering.

[0026] During coking, volatiles and pyrolysis products migrate from the interior of the material to the exterior and are discharged. The efficiency of this migration typically depends on the mass transfer driving force between the material's interior and the external environment. In the initial stages of coking, the high content of volatile components within the material and the low concentration of corresponding gases in the external environment create a significant concentration difference, making it easier for volatiles to precipitate and be discharged. However, as coking continues, the volatile components in the surface and shallow layers of the material gradually decrease, while the concentration of pyrolysis products in the furnace gradually increases. This leads to a decrease in the concentration difference between the interior and exterior, a reduction in the mass transfer driving force, and consequently, a decrease in coking efficiency in the later stages. Therefore, single-pass continuous coking often suffers from a rapid initial processing speed followed by a slower processing effect in the later stages, easily leading to prolonged processing cycles and even incomplete local coking or excessive volatile residues, ultimately affecting the subsequent sintering quality.

[0027] Please refer to Figure 1 and Figure 2 As shown, to solve the above-mentioned technical problems, this application discloses a rotary kiln, comprising: The furnace body 10 forms a processing space 11; The tray 20 is rotatably connected to the furnace body 10 and is set in the processing space 11 to support the material to be processed; Heating element 30 is disposed in the processing space 11 to heat the processing space 11; The processing space 11 is divided into at least a first heating zone and a second heating zone in the circumferential direction of the rotating tray 20. The first heating zone and the second heating zone exhibit different temperature curves during operation.

[0028] This application divides the processing space 11 of the furnace body 10 into at least two heating zones with different temperature curves in the circumferential direction of the rotating tray 20, and uses the tray 20 to drive the material to be processed to rotate, so that the material can repeatedly pass through different temperature zones in a single processing. This combination of circumferential partitioning and rotational motion realizes the periodic temperature change of the material in the spatial dimension: when the material passes through the lower temperature of the first heating zone and the second heating zone, the organic matter in the material undergoes thermal decomposition and releases gas, that is, coking occurs (hereinafter, the reaction at the conventional coking temperature is referred to as low-temperature coking). As low-temperature coking proceeds, on the one hand, more undissipated gaseous products accumulate in the gaps of the material, and on the other hand, the content of easily pyrolyzable components in the material decreases. The decrease in reactant concentration and the increase in product concentration simultaneously inhibit the coking process, which is commonly known in the industry as the semi-coking state. Subsequently, the material arrives at the higher temperature zone between the first and second heating zones. At this point, the high temperature stimulates the previously difficult-to-pyrolyze components to undergo pyrolysis (hereinafter referred to as high-temperature coking). On the one hand, it generates the reactants required for low-temperature coking. On the other hand, since the products of high-temperature coking and low-temperature coking are different, the high-temperature coking process also provides time for the gaseous products of the low-temperature coking process to escape. During the high-temperature coking process, the concentration of reactants in low-temperature coking increases and the concentration of products decreases. When the material rotates with the tray 20 to undergo low-temperature coking again, it can react with higher efficiency.

[0029] In existing technologies, a single temperature profile is typically used for coking. As the process progresses, the accumulation of pyrolysis products in the furnace leads to a decrease in mass transfer driving force, resulting in a significant reduction in coking efficiency in the later stages. This application, through a combination of zoned heating and rotary circulation, enables the material to repeatedly experience different heating environments during coking without increasing equipment length or the number of batches. This effectively overcomes the problem of decreased efficiency in the later stages of traditional coking, resulting in more complete removal of volatiles from the material, more uniform coking, and a shorter processing cycle. Simultaneously, it provides a more stable precursor for subsequent sintering.

[0030] It should be understood that the first heating zone and the second heating zone in this application are not specific physical partitions, but rather effect partitions achieved through method control. These partitions can be achieved through differences in furnace structure and the physical arrangement of the heating elements 30, or through the parameters of the heating elements 30 and software control. As long as the temperature curves of the two zones differ, the technical effect of this application can be achieved. Similarly, the furnace body 10 can adopt any existing structure. For example, it includes a shell 15 and an insulation layer 14 disposed within the shell 15, the insulation layer 14 being formed by stacked insulation bricks. The furnace body 10 also includes a viewing window 43, functional components 44 such as thermocouples, functional ports 45 such as atmosphere / furnace pressure detection ports, and air inlets 46 and outlets 47, etc.

[0031] Regarding the above principles of this application, the following supplementary explanations should also be made: Under normal circumstances, high-temperature coking breaks down large-molecule organic matter and heavy tar into small-molecule organic matter and light tar, which is the description of the reactants generated by high-temperature coking in the above principle. However, in some embodiments, high-temperature coking may also generate products that are not reactants of low-temperature coking. In this case, although it cannot increase the reactants of low-temperature coking, it at least provides an escape gap for the gaseous products of low-temperature coking. Moreover, the reactants and / or products of high-temperature coking are different from those of low-temperature coking, and they can consume organic matter to a certain extent without being limited by the mass transfer driving force of low-temperature coking. A good example is the coking of polyolefin adhesives. In the low-temperature coking process, the typical reaction is random cleavage to generate waxy hydrocarbons and long-chain olefins, etc. However, in high-temperature coking (usually above 700°C), a large number of monocyclic aromatic hydrocarbons will appear in the products, and even further condense to generate polycyclic aromatic hydrocarbons such as naphthalene and anthracene under the action of certain catalysts or higher temperatures. In this case, although high-temperature coking cannot supplement the reactants of low-temperature coking, it is still another form of coking, which improves the average coking efficiency of the system.

[0032] In the applicant's previous products, there was a circulating heat treatment production line, that is, the material was reintroduced into the production line downstream of the coking-sintering line for secondary or even tertiary processing, which to some extent could improve the mass transfer driving force and make coking more thorough. However, the rotary kiln of this application also has advantages over the above solutions. The material of this application is processed entirely inside the closed furnace body 10, and its atmosphere control and temperature control are far superior to the above solutions. The product quality obtained by the technical solution of this application, especially in terms of oxidation degree, is superior to the above solutions.

[0033] Furthermore, this application merely specifies that the first heating zone and the second heating zone have different temperature curves. This can be understood as the first heating zone and the second heating zone respectively performing low-temperature coking and high-temperature coking, or as one performing coking and the other performing sintering; or even, both performing low-temperature coking and high-temperature coking first, followed by temperature-controlled sintering. That is, coking and subsequent high-temperature treatment (such as sintering) are integrated into one device to further simplify the process flow. In other words, although the explanation of this embodiment tends to describe the rotary kiln of this application as a device capable of high-low temperature composite coking, in other solutions of this application, this can also be a comprehensive device with coking and sintering effects. For specific examples, please refer to the following embodiments.

[0034] According to one embodiment of this application, the furnace body 10 includes a furnace body 12 and a furnace bottom 13. The furnace bottom 13 is vertically connected to the furnace body 12 to enclose and form a processing space 11. The tray 20 is disposed on the furnace bottom 13 and can move in and out of the processing space 11 with the furnace bottom 13.

[0035] In this embodiment, the furnace bottom 13 is designed as a liftable structure, allowing the tray 20 to rise and fall together with the furnace bottom 13, thereby enabling the entire material to enter and exit the processing space 11: when the furnace bottom 13 rises to form a closed processing space 11, the tray 20 is in the working position for rotary heat treatment; when loading and unloading are required, the furnace bottom 13 lowers to allow the tray 20 to be lowered out, facilitating quick material handling. Compared to a fixed furnace bottom 13 or a side-opening furnace door structure, this design significantly improves the convenience and efficiency of loading and unloading, and is compatible with automated operation; on the other hand, it avoids the disturbance to the temperature and atmosphere fields inside the furnace caused by frequent opening of the furnace door, helping to maintain processing stability. Simultaneously, the integrated lifting of the tray 20 and the furnace bottom 13 ensures that the material maintains a horizontal posture during entry and exit, preventing displacement or damage to the billet due to handling, which is especially suitable for fragile formed billets requiring precise positioning. Furthermore, the tray 20 is not limited to rotating during processing; it can also rotate during loading and unloading to facilitate loading and unloading from one side of the equipment.

[0036] For example, the furnace bottom 13 is raised and lowered by a motor 48 fixed thereon in cooperation with a vertically arranged lead screw 41. It can also be raised and lowered by a winch, rack and pinion, etc. Preferably, the furnace bottom 13 is raised and lowered by the threaded lead screw 41 to ensure its support capacity. In order to facilitate the maintenance of the furnace body 10, a maintenance platform 42 can also be provided around the furnace body 12.

[0037] According to one embodiment of this application, the heating element 30 is disposed on the furnace body 12 and / or the furnace bottom 13.

[0038] This embodiment provides a specific arrangement of the heating element 30. When the heating element 30 is set on the furnace body 12, it can be distributed circumferentially to form temperature difference zones, which facilitates the material to undergo heat treatment through different temperature curves during the rotation of the tray 20. Moreover, wall heating helps to maintain the stability of the circumferential temperature field of the processing space 11. When the heating element 30 is set on the furnace bottom 13, it can directly conduct heat to the tray 20 and the supported material, which helps to improve the heating rate and temperature uniformity of the bottom area. It is especially suitable for scenarios that require enhanced bottom heat transfer or have special temperature requirements for the bottom of the material. The combination of the two arrangements can realize composite heating, taking into account both circumferential zone control and uniform bottom heat transfer, further improving the adaptability of the equipment to complex processes.

[0039] According to one embodiment of this application, the heating element 30 is disposed on one side of the processing space 11 in the circumferential direction, so that the side close to the heating element 30 forms a first heating zone and the side away from the heating element 30 forms a second heating zone, and the working temperature of the first heating zone is higher than that of the second heating zone.

[0040] In this embodiment, the heating element 30 is positioned on one side of the processing space 11. Utilizing natural heat transfer, a high-temperature first heating zone near the heating element 30 and a low-temperature second heating zone away from the heating element 30 are formed without adding additional partitions or complex temperature control structures. This single-sided arrangement is not only simple and easy to set up, but also creates a smooth temperature transition zone between the two heating zones due to the natural diffusion of heat from the high-temperature zone to the low-temperature zone, avoiding thermal stress damage to the material that may be caused by sudden temperature changes. When the tray 20 carrying the material rotates through this temperature gradient zone, the temperature change experienced by the material is continuous and uniform, which helps maintain the stability of the internal temperature and stress fields of the material.

[0041] According to one embodiment of this application, the heating element 30 is arranged circumferentially along the heating space, and multiple heating elements 30 are configured to be independently controlled. In the first step of the initial processing stage, the working temperature of the first heating zone and the second heating zone is both the first temperature. In the subsequent second step, the temperature of the first heating zone is adjusted to the second temperature, which is higher than the first temperature.

[0042] In the initial processing step, both the first and second heating zones maintain a relatively low initial temperature, allowing the material to undergo a uniform preheating stage before entering the formal processing stage. This avoids excessive internal thermal stress or premature surface densification that hinders volatilization caused by direct exposure to a high-temperature environment. In the subsequent second processing step, the temperature of the first heating zone is adjusted to a higher second temperature, thereby creating a temperature difference in the circumferential direction. Combined with the rotation of tray 20, this allows the material to circulate through different temperature zones. This step-by-step control method ensures the safety of the material during the initial heating stage while creating conditions for subsequent zoned cyclic processing. Especially in a one-furnace processing technology where the first temperature is the coking temperature and the second temperature is the sintering temperature, the setup in this embodiment can significantly reduce the scrap rate caused by concentrated gas release.

[0043] It should be understood that while the first step is described as a preheating stage in this embodiment, it does not mean that no chemical changes occur in the material during the first step. The first temperature can be set as needed. A preferred example is that the first temperature is set to the temperature for low-temperature coking, and the second temperature is set to the temperature for high-temperature coking. In this way, low-temperature coking can also be understood as preheating for high-temperature coking, avoiding the concentrated release of gas caused by direct high-temperature coking of the material, which could lead to bulging and cracking. Alternatively, in an embodiment where the first temperature is the coking temperature and the second temperature is the sintering temperature, coking can also be understood as a preheating treatment for sintering.

[0044] For example, the first temperature is 200℃-800℃ for coking / pyrolysis of the material to be processed; the second temperature is 1100℃-1700℃ for sintering the material to be processed. Alternatively, the first temperature is 200℃-500℃ for low-temperature coking of the material to be processed, and the second temperature is 600℃-850℃ for high-temperature coking of the material to be processed.

[0045] Furthermore, in the initial first step of processing, both the first and second heating zones operate at a first temperature. In the subsequent second step, the temperature of the first heating zone is adjusted to a second temperature, which is higher than the first temperature. In the final third step, both the first and second heating zones are adjusted to a third temperature, which is higher than the second temperature. Specifically, the first temperature is 200℃-500℃, used for low-temperature coking of the material to be processed; the second temperature is 600℃-850℃, used for high-temperature coking of the material to be processed; and the third temperature is 1100℃-1700℃, used for sintering the material to be processed.

[0046] This embodiment realizes the complete process from zoned cyclic coking to final sintering in a single device: In the first step, both zones maintain a low first temperature, allowing the material to coke at a low temperature, initially precipitating volatile components and forming a semi-coke state; after the initial preheating in the first step, the first heating zone is raised to a higher second temperature in the second step, creating a temperature difference in the circumferential direction, allowing the material to circulate through the low-temperature and high-temperature zones as the tray 20 rotates, with low-temperature coking and high-temperature coking cycling to achieve better coking results; in the third step, both zones are adjusted to a higher third temperature, allowing the coked material to be sintered and densified in a uniform temperature field. The control method of this embodiment integrates the low-temperature coking, high-temperature coking, and sintering processes, which originally required multiple devices or multiple furnace loadings, into a single device, avoiding the risks of cooling and contamination when transferring materials between different devices.

[0047] According to one embodiment of this application, in the second step, the heating power of the plurality of heating elements 30 is distributed in a gradient along the rotational circumference of the tray 20 to form a temperature transition between the first heating zone and the second heating zone.

[0048] In this embodiment, the heating power of the multiple heating elements 30 is set to a gradient distribution along the circumference of the tray 20, so that there is no obvious temperature boundary between the first heating zone and the second heating zone, but rather a transitional region with continuous temperature change. When the tray 20 carries the material and rotates through this region, the temperature change experienced by the material is smooth and gradual, avoiding thermal stress concentration or localized material damage that may be caused by sudden temperature changes. Each time the material enters the high-temperature zone or returns to the low-temperature zone, there is a buffer adaptation process, which helps to maintain the uniformity of the internal temperature field of the material, and is especially suitable for forming blanks that are sensitive to the heating rate or have a fragile structure.

[0049] According to one embodiment of this application, the furnace body 10 is further provided with an air inlet 46 and an air outlet 47 that communicate with the processing space 11. The air inlet 46 is located in the first heating zone and is used to introduce a protective atmosphere. The air outlet 47 is located in the second heating zone and is used to discharge the gas in the processing space 11.

[0050] The first heating zone, as a low-temperature coking area, needs to continuously extract gaseous products from the pores of the material to maintain the concentration difference inside and outside the material and promote the release of volatiles. The second heating zone, as a high-temperature area, is more sensitive to impurities in the atmosphere (such as pyrolysis products, tar, etc.). Placing the outlet 47 in this zone ensures the purity of the atmosphere in the high-temperature zone and avoids secondary reactions or deposition of pyrolysis products at high temperatures. In this embodiment, by placing the inlet 46 in the first heating zone and the outlet 47 in the second heating zone, the functional requirements of different temperature zones are fully considered.

[0051] According to one embodiment of this application, the tray 20 is configured to rotate continuously or in steps so that the material to be processed repeatedly passes through the first heating zone and the second heating zone.

[0052] In this embodiment, by configuring the tray 20 to rotate continuously or in a stepping manner, the material to be processed can repeatedly pass through the first heating zone and the second heating zone. In continuous rotation mode, the material shuttles between different temperature zones at a constant speed, which is suitable for process scenarios that require uniform heating and frequent temperature zone switching. It can ensure that the interval time of each cycle is consistent, so that the coking process can continue to advance steadily. In stepping rotation mode, the material can stay in each temperature zone for a set time, which is suitable for process scenarios that need to complete a specific reaction in a certain temperature zone before moving to the next temperature zone.

[0053] According to one embodiment of this application, the processing space 11 is cylindrical, and the tray 20 rotates about the central axis of the processing space 11.

[0054] In this embodiment, the processing space 11 is set as a cylinder, and the tray 20 rotates around its central axis, achieving a match between the rotational motion of the tray 20 and the geometry of the processing space 11. The cylindrical space ensures that during the rotation of the tray 20, the distance between the material at any position and the furnace body 12 and the circumferentially arranged heating elements 30 remains constant, guaranteeing uniform heating conditions for the material on the same circumference and avoiding temperature dead zones or uneven heating caused by irregular spatial shapes. It should be noted that the order of description of the embodiments in this application is not intended to limit the priority of the embodiments.

[0055] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application and in its specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0056] The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. In this application, "at least one" means one or more, and "more than one" means two or more. The terms "first," "second," and other ordinal terms used in this application may be used to describe various constituent elements, but these constituent elements are not limited by these terms. The purpose of using these terms is solely to distinguish one constituent element from others and should not be construed as indicating or implying relative importance. For example, without departing from the scope of this application, a first constituent element may be named a second constituent element, and similarly, a second constituent element may be named a first constituent element.

[0057] Each component may be described or referred to as "used for" performing one or more tasks. In this context, "used for" is used to imply a structure by indicating that the component includes a structure that performs one or more tasks during operation. Therefore, even when a specified component is currently inoperable (e.g., not turned on), it can still be referred to as "used for performing that task." Components used with the term "used for" include hardware.

[0058] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many forms under the guidance of this application without departing from the spirit and scope of protection of the claims. All equivalent transformations made under the inventive concept of this application using the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A rotary kiln, comprising: The furnace body (10) forms a processing space (11); The tray (20) is rotatably connected to the furnace body (10) and set in the processing space (11) to support the material to be processed; A heating element (30) is disposed within the processing space (11) for heating the processing space (11); The feature is that the processing space (11) is divided into at least a first heating zone and a second heating zone in the circumferential direction of the tray (20), and the first heating zone and the second heating zone exhibit different temperature curves during operation.

2. The rotary kiln according to claim 1, characterized in that, The furnace body (10) includes a furnace body (12) and a furnace bottom (13). The furnace bottom (13) is vertically connected to the furnace body (12) to enclose and form the processing space (11). The tray (20) is set on the furnace bottom (13) and can move in and out of the processing space (11) with the furnace bottom (13).

3. The rotary kiln according to claim 2, characterized in that, The heating element (30) is disposed on the furnace body (12) and / or the furnace bottom (13).

4. The rotary kiln according to claim 1, characterized in that, The heating element (30) is disposed on one side of the processing space (11) in the circumferential direction, so that the side close to the heating element (30) forms the first heating zone and the side away from the heating element (30) forms the second heating zone, and the working temperature of the first heating zone is higher than that of the second heating zone.

5. The rotary kiln according to claim 1, characterized in that, The heating element (30) is arranged circumferentially along the heating space. Multiple heating elements (30) are configured to be independently controlled. In the first step of the initial processing stage, the working temperature of the first heating zone and the second heating zone is the first temperature. In the subsequent second step, the temperature of the first heating zone is adjusted to the second temperature, which is higher than the first temperature.

6. The rotary kiln according to claim 5, characterized in that, In the second step, the heating power of the plurality of heating elements (30) is distributed in a gradient along the circumferential rotation of the tray (20) to form a temperature transition between the first heating zone and the second heating zone.

7. The rotary kiln according to claim 5, characterized in that, The first temperature is 200℃-800℃, used to coke / pyrolyze the material to be processed; The second temperature is 1100℃-1700℃, used to sinter the material to be processed.

8. The rotary kiln according to claims 5-7, characterized in that, The furnace body (10) is also provided with an air inlet (46) and an air outlet (47) that are connected to the processing space (11). The air inlet (46) is located in the first heating zone and is used to introduce a protective atmosphere. The air outlet (47) is located in the second heating zone and is used to discharge the gas in the processing space (11).

9. The rotary kiln according to any one of claims 1-8, characterized in that, The tray (20) is configured to rotate continuously or in steps so that the material to be processed repeatedly passes through the first heating zone and the second heating zone.

10. The rotary kiln according to any one of claims 1-8, characterized in that, The processing space (11) is cylindrical, and the tray (20) rotates around the central axis of the processing space (11).

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