rotary furnace
By adopting a combination design of spiral guide plates and lifting plates in the rotary kiln, the problems of material accumulation and uneven distribution are solved, and the material is evenly distributed and fully reacted in the rotary kiln, thereby improving product quality and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XTC NEW ENERGY MATERIALS(XIAMEN) LTD
- Filing Date
- 2026-02-12
- Publication Date
- 2026-05-29
Smart Images
Figure CN122107762A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thermal equipment technology, and in particular to a rotary kiln. Background Technology
[0002] In industrial production, rotary kilns are widely used in processes such as material heating, drying, calcination, and chemical reactions. Through the continuous rotation of the kiln body, the material inside is constantly tumbled, thereby achieving uniform contact and heat and mass transfer between the material and the heat medium (such as hot airflow) to meet specific process requirements.
[0003] Currently, rotary kilns typically consist of a furnace body, rotating furnace tubes, a heating device, and a transmission device. The material enters the rotary furnace tube from the feed port at the furnace head end, is continuously agitated as the furnace tube rotates, and exchanges heat or reacts with the incoming hot gas flow. Finally, it is discharged from the discharge port at the furnace tail end, thus completing the entire heating or reaction process.
[0004] However, the aforementioned rotary kilns are prone to material accumulation during operation, resulting in uneven material distribution within the kiln and thus affecting product quality. Summary of the Invention
[0005] This application provides a rotary kiln, the technical solution of which is as follows: The rotary kiln includes: A rotary furnace tube, one end of which has a feed inlet; The first spiral guide plate is installed on the inner wall of the rotary kiln tube and is arranged adjacent to the feed port; Multiple second spiral guide plates are installed at intervals along the axial direction of the rotary kiln tube on the inner wall of the rotary kiln tube, and are all located on the side of the first spiral guide plate away from the feed inlet.
[0006] Optionally, the number of spiral turns of the first spiral guide plate and the number of spiral turns of the second spiral guide plate are both greater than one, and the pitch of the first spiral guide plate is greater than or equal to the pitch of the second spiral guide plate. In the radial direction of the rotary kiln tube, the height of the first spiral guide plate is greater than the height of the second spiral guide plate.
[0007] Optionally, the plurality of second spiral guide plates include a plurality of in-furnace spiral guide plates and at least one furnace tail spiral guide plate, and the other end of the rotary furnace tube has a discharge port; The plurality of in-furnace spiral guide plates are installed at intervals along the axial direction of the rotary furnace tube on the inner wall of the rotary furnace tube; The furnace tail spiral guide plate is located on the side of the plurality of furnace spiral guide plates facing the discharge port; Wherein, the pitch of the spiral guide plate at the tail of the furnace is greater than or equal to the pitch of the spiral guide plate in the furnace.
[0008] Optionally, the number of spiral turns of the first spiral guide plate is greater than or equal to the number of spiral turns of the second spiral guide plate, and the number of spiral turns of the furnace tail spiral guide plate is greater than the number of spiral turns of the furnace middle spiral guide plate.
[0009] Optionally, the rotary kiln further includes multiple lifting plate groups, each lifting plate group including multiple lifting plates, the multiple lifting plate groups being fixed at intervals along the axial direction of the rotary kiln tube on the inner wall of the rotary kiln tube, and the multiple lifting plates in each lifting plate group being arranged at intervals along the axial direction of the rotary kiln tube; The feeding plate assembly and the second spiral guide plate are alternately arranged in the axial direction of the rotary kiln tube.
[0010] Optionally, the plurality of lifting plate groups are at least divided into a furnace head lifting plate group, a furnace middle lifting plate group, and a furnace tail lifting plate group, and the other end of the rotary furnace tube has a discharge port; The furnace head feeding plate assembly is located on the side of the first spiral guide plate away from the feed inlet and is arranged adjacent to the first spiral guide plate; The tail-end material-lifting plate group is arranged adjacent to the discharge port; The furnace lifting plate group is located between the furnace head lifting plate group and the furnace tail lifting plate group.
[0011] Optionally, the radial deflection angle of the lifting plate in the furnace head lifting plate group is greater than or equal to the radial deflection angle of the lifting plate in the furnace middle lifting plate group and the radial deflection angle of the lifting plate in the furnace tail lifting plate group. Wherein, the radial deflection angle is the angle between the intersection line formed by the intersection of the surface of the feeding plate and the first plane and the tangent of the rotation direction of the rotary furnace tube, and the first plane is a plane perpendicular to the axis of the rotary furnace tube.
[0012] The radial deflection angle of the lifting plate in the tail of the furnace is less than or equal to the radial deflection angle of the lifting plate in the furnace. At least some of the lifting plates in the tail of the furnace have an acute angle between their working surfaces and the rotation axis of the rotary furnace tube, and the opening of the acute angle faces the discharge port. At least some of the lifting plates in the furnace head lifting plate group and at least some of the lifting plates in the furnace lifting plate group are parallel to the rotation axis of the rotary furnace tube.
[0013] Optionally, along the circumference of the rotary furnace tube, the distribution density of the lifting plates in the furnace lifting plate group is greater than or equal to the distribution density of the lifting plates in the furnace head lifting plate group. The distribution density of the lifting plates in the furnace head lifting plate group is greater than or equal to the distribution density of the lifting plates in the furnace tail lifting plate group.
[0014] Optionally, the rotary furnace tube has multiple process temperature zones and multiple heating components arranged along the axial direction of the rotary furnace tube, and the multiple heating components are respectively used to heat the multiple process temperature zones; The second spiral guide plate is located at the separation position between adjacent process temperature zones inside the rotary furnace tube.
[0015] The beneficial effects of the technical solutions provided in this application include at least the following: A rotary kiln is provided, comprising a rotary kiln tube, a first spiral guide plate, and multiple second spiral guide plates. The first spiral guide plate is installed on the inner wall of the rotary kiln tube and is arranged adjacent to the feed inlet. Multiple second spiral guide plates are installed at intervals along the axial direction of the rotary kiln tube on its inner wall, all located on the side of the first spiral guide plate away from the feed inlet. Thus, by arranging the first spiral guide plate at the beginning of the kiln head, newly added material can be quickly pushed into the kiln, preventing accumulation at the feed inlet and ensuring uniform material distribution in the initial stage. In the kiln's interior and rear areas, multiple second spiral guide plates are spaced apart to smoothly control the axial propulsion speed of the material, resulting in a more uniform material layer thickness within the kiln.
[0016] Furthermore, by segmenting spiral guide plates and lifting plates with differentiated structural parameters within the rotary kiln tube and arranging them alternately and collaboratively in the axial direction, problems such as material accumulation, uneven reaction, and low production efficiency can be solved. Specifically, by placing a first spiral guide plate with a larger pitch and plate height at the beginning of the furnace head, rapid material introduction and forced conveying can be achieved, preventing material accumulation at the feed inlet and ensuring initial uniform distribution and smooth conveying of materials within the furnace tube. Furthermore, by placing a second spiral guide plate with a smaller pitch in the furnace middle and tail areas, the axial movement speed and residence time of materials in each process section can be precisely controlled. Simultaneously, lifting plates with a small radial deflection angle and high distribution density are configured in the furnace middle area to enhance radial mixing and heat exchange of materials, ensuring uniform heating and sufficient reaction, thereby improving product quality consistency.
[0017] Furthermore, by employing lifting plates with a large radial deflection angle and low distribution density at the furnace head, necessary turning is achieved while suppressing dust loss. An axial tilt angle is added to the lifting plates at the furnace tail, facing the discharge port, giving them an active guiding function for material discharge and solving the problem of material accumulation at the tail end. Thus, through differentiated design for each functional zone, mixing and reaction efficiency are improved while ensuring smooth and stable material flow, thereby enhancing the overall capacity and operational continuity of the rotary kiln. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments 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 these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the structure of a rotary kiln provided in an embodiment of this application; Figure 2 yes Figure 1 A schematic diagram of the rotary kiln from another perspective; Figure 3 yes Figure 2 The diagram shows a cross-sectional structure of the rotary kiln along the A1-A2 position; Figure 4 This is a schematic diagram of the cross-sectional structure of another rotary kiln provided in an embodiment of this application; Figure 5 yes Figure 4 A partial structural schematic diagram of the rotary kiln shown; Figure 6 This is a schematic diagram of the exploded structure of a rotary kiln provided in an embodiment of this application; Figure 7 yes Figure 2 The diagram shows a structural schematic of the rotary kiln from another perspective; Figure 8 yes Figure 7 The diagram shows a cross-sectional structure of the rotary kiln along the B1-B2 position; Figure 9 yes Figure 7 A schematic diagram of a cross-sectional structure of the rotary kiln along the C1-C2 position is shown. Figure 10 yes Figure 7 The diagram shows a cross-sectional structure of the rotary kiln along the D1-D2 position; Figure 11 This is a schematic diagram of the structure of a material-lifting plate with a radial deflection angle of 135° provided in an embodiment of this application; Figure 12This is a schematic diagram of the structure of a feeding plate with a radial deflection angle of 90° provided in an embodiment of this application; Figure 13 This is a schematic diagram of the structure of a feeding plate with a radial deflection angle of 45° provided in an embodiment of this application; Figure 14 yes Figure 11 The diagram shows the simulation results of a material handling plate with a radial deflection angle of 135°. Figure 15 yes Figure 12 The diagram shows the simulation results of a material lifting plate with a radial deflection angle of 90°. Figure 16 yes Figure 13 The diagram shows the simulation results of a material lifting plate with a radial deflection angle of 45°. Figure 17 yes Figure 11 The diagram shows the actual operation of the material lifting plate with a radial deflection angle of 135°. Figure 18 yes Figure 12 The diagram shows the actual operation of the material lifting plate with a radial deflection angle of 90°. Figure 19 yes Figure 13 The diagram shows the actual operation of the material lifting plate with a radial deflection angle of 45°. Figure 20 yes Figure 11 The diagram shows the dust emission test results of a material lifting plate with a radial deviation angle of 135°. Figure 21 yes Figure 12 The diagram shows the dust emission test results of a material lifting plate with a radial deflection angle of 90°. Figure 22 yes Figure 13 The diagram shows the dust emission test results of a material lifting plate with a radial deviation angle of 45°. Figure 23 This is a partial cross-sectional structural diagram of a rotary kiln provided in an embodiment of this application.
[0020] Explanation of reference numerals in the attached figures: Rotary furnace tube 11, feed inlet k1, discharge outlet k2, process temperature zone w1, feed zone w2, discharge zone w3; first spiral guide plate 12, pitch d1 of the first spiral guide plate 12, plate height h1 of the first spiral guide plate 12, spiral angle c1; second spiral guide plate 13, pitch d2 of the second spiral guide plate 13, plate height h2 of the second spiral guide plate 13; spiral guide plate 131 in the furnace, spiral guide plate 13 at the furnace tail. 2. Flush plate assembly 14, flush plate 140, furnace head flush plate assembly 141, furnace head flush plate 1411, furnace middle flush plate assembly 142, furnace middle flush plate 1421, furnace tail flush plate assembly 143, furnace tail flush plate 1431, radial deflection angle c2 of furnace head flush plate 1411, radial deflection angle c3 of furnace middle flush plate 1421, radial deflection angle c4 of furnace tail flush plate 1431, axial tilt angle c5, rotation direction z1, rotation axis z2. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0022] Although this application can readily be embodied in various forms, only some specific embodiments are shown in the accompanying drawings and will be described in detail in this specification. It is understood that this specification should be regarded as an exemplary illustration of the principles of this application and is not intended to limit the application to what is described herein.
[0023] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of this application, and does not imply that every embodiment of this application must have the described feature. Furthermore, it should be noted that this specification describes many features. While certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.
[0024] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various elements of this application are relative rather than absolute. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, these directional indications also change accordingly.
[0025] Rotary furnaces, as a type of thermal equipment, are used in many industrial fields such as metallurgy, chemical industry, building materials, and environmental protection. For example, they can be used to dry, calcine, roast, and perform various solid-phase chemical reactions. The basic working principle of a rotary furnace relies on the continuous rotation of the furnace body, which drives the internal furnace tubes to rotate as well. This causes the material placed inside to rise to a certain height along the wall, where it continuously tumbles, scatters, and mixes under the influence of gravity. This cyclical motion promotes sufficient contact and efficient heat and mass transfer between material particles and between the material and the hot gas flow (or other heat medium) introduced into the furnace, thereby achieving the preset process objectives.
[0026] Currently, rotary kilns mainly consist of a furnace body support, rotary kiln tubes, a heating device, and a transmission device. The furnace body support serves as the main structure and provides support. The heating device provides heat for the process; for example, it can include electric heating wires or external radiant heaters. The transmission device drives the rotary kiln tubes to rotate at a specific speed; for example, it can include a motor, a reducer, and gears. During operation, the material to be processed is continuously or intermittently fed into the rotary kiln tubes via a feeding device located at one end of the kiln. As the rotary kiln tubes rotate, the material is lifted and scattered by the inner wall of the tubes or built-in components (such as lifting plates). During this process, it undergoes heat exchange or chemical reaction with the opposing or co-current flow of hot air. The processed material is discharged from the outlet at the other end of the rotary kiln.
[0027] The aforementioned rotary kiln also suffers from the following problems during operation. First, in the feeding section of the rotary kiln tube, the initial feeding momentum is difficult to match with the fluidization movement of the material inside the furnace, causing the material initially entering the rotary kiln tube to easily stagnate and accumulate near the feed inlet. Second, in the middle and rear sections of the rotary kiln tube, which bear the main reaction function, the adequacy of material mixing mainly relies on the simple lifting plates, resulting in insufficient material agitation and mixing, leading to uneven reaction within the rotary kiln tube and affecting product quality. Furthermore, the aforementioned rotary kiln mainly relies on the slight tilt angle of the overall furnace body, utilizing the natural sliding caused by the gravity component of the material to achieve axial conveying. This results in prolonged material reaction time and reduced production efficiency.
[0028] This application provides a rotary kiln that can solve some or all of the problems in the aforementioned related technologies.
[0029] Please refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 This is a schematic diagram of the structure of a rotary kiln provided in an embodiment of this application. Figure 2 yes Figure 1 The diagram shows another structural view of the rotary kiln. Figure 3 yes Figure 2The diagram shows a cross-sectional structure of a rotary kiln along the A1-A2 axis. The rotary kiln may include a rotary kiln tube 11, a first spiral guide plate 12, and multiple second spiral guide plates 13. One end of the rotary kiln tube 11 has a feed inlet, and the other end has a discharge outlet k2. The first spiral guide plate is installed on the inner wall of the rotary kiln tube 11 and is adjacent to the feed inlet. Multiple second spiral guide plates 13 are installed at intervals along the axial direction of the rotary kiln tube 11 on the inner wall of the rotary kiln tube 11, and are all located on the side of the first spiral guide plate 12 away from the feed inlet. That is, the first spiral guide plate 12 is fixed to the inner wall of the rotary kiln tube 11 and arranged close to the feed inlet. The multiple second spiral guide plates 13 are arranged at intervals along the axial direction of the rotary kiln tube 11 and are all located downstream of the first spiral guide plate 12. The first spiral guide plate 12 and the second spiral guide plates 13 can be fixed to the inner wall of the rotary kiln tube 11 by welding or bolting.
[0030] In this embodiment, when the rotary kiln tube 11 rotates, the fixed first spiral guide plate 12 and multiple second spiral guide plates 13 generate an axial thrust on the material, similar to screw propulsion, thereby actively pushing the material through the built-in spiral guide plates. Specifically, the first spiral guide plate 12 is positioned at the beginning of the furnace head of the rotary kiln tube 11. This first spiral guide plate 12 can quickly push newly introduced material into the rotary kiln tube 11, avoiding material accumulation at the inlet and ensuring uniform initial material distribution. Multiple second spiral guide plates 13 are spaced apart in the furnace and tail areas of the rotary kiln tube 11. These multiple second spiral guide plates 13 smoothly control the axial propulsion speed of the material, resulting in a more uniform material layer thickness inside the rotary kiln tube 11. Furthermore, by adjusting the parameters (such as pitch) of the spiral guide plates in different sections, the required material residence time for each process stage can be precisely matched, prompting more fully reacted material to be removed promptly, thus improving the overall uniformity of material heating and reaction.
[0031] In summary, this application provides a rotary kiln comprising a rotary kiln tube 11, a first spiral guide plate 12, and multiple second spiral guide plates 13. The first spiral guide plate is installed on the inner wall of the rotary kiln tube 11 and is adjacent to the feed inlet. Multiple second spiral guide plates 13 are installed at intervals along the axial direction of the rotary kiln tube 11 on the inner wall of the rotary kiln tube 11, and are all located on the side of the first spiral guide plate 12 away from the feed inlet. Thus, by arranging the first spiral guide plate 12 at the beginning of the kiln head of the rotary kiln tube 11, newly added material can be quickly pushed into the kiln, preventing accumulation at the feed inlet and ensuring uniform material distribution in the initial stage. In the kiln and tail areas, multiple second spiral guide plates 13 are spaced apart to smoothly control the axial propulsion speed of the material, making the material layer thickness in the kiln more uniform, thereby solving the problems of uneven material distribution and poor product quality in related technologies.
[0032] Please refer to Figure 3 and Figure 4 , Figure 4 This is a schematic cross-sectional view of another rotary kiln provided in an embodiment of this application. In an optional embodiment, the rotary kiln tube 11 has multiple process temperature zones w1 arranged along the axial direction of the rotary kiln tube 11 and multiple heating components, each of which is used to heat the multiple process temperature zones w1. The second spiral guide plate 13 is located at the separating position between adjacent process temperature zones w1 within the rotary kiln tube 11. In other words, the rotary kiln tube 11 is divided into multiple process temperature zones w1 along its axial direction to improve the accuracy of process control. Each temperature zone is equipped with an independent heating component to achieve zoned temperature control. The second spiral guide plate 13 is disposed at the separating position between adjacent process temperature zones w1 within the rotary kiln tube 11.
[0033] When material moves from one process temperature zone w1 to the next process temperature zone w1, it can pass through the second spiral guide plate 13 located at the junction. The structural parameters of this spiral guide plate (such as pitch and plate height) can be specifically designed according to the specific process requirements of the preceding and following process temperature zones w1 (such as the expected heating rate or the necessary reaction time), thereby actively adjusting the speed at which the material crosses the temperature zone boundary to achieve coordinated control of material conveying and temperature field.
[0034] In this way, the static temperature field distribution can be linked to the dynamic material conveying control. By matching spiral guide plates with corresponding propulsion capabilities to the boundaries of different temperature zones, the local residence time of materials can be precisely preset according to the preset temperature curve. For example, before the inlet of the high-temperature zone where materials need to pass through quickly to avoid overheating, a spiral guide plate with a larger pitch can be set to accelerate the propulsion; while in the constant-temperature zone where sufficient reaction is required, a spiral guide plate with a smaller pitch is used to prolong the residence time. This enhances the applicability of the rotary kiln to complex processes, thereby improving the consistency and stability of product quality.
[0035] In one exemplary embodiment, the number of spiral guide plates in the rotary kiln tube 11 affects the residence time of the material; generally, the more spiral guide plates there are, the longer the residence time. Therefore, the number of spiral guide plates can be n+1 to n+3, where n is the number of process temperature zones w1. It should be noted that in this embodiment, the process temperature zone w1 is located only in the middle section of the rotary kiln tube 11, with a feeding zone w2 and a discharging zone w3 respectively located at both ends, together forming a complete material handling channel.
[0036] Please refer to Figure 3 , Figure 4 and Figure 5 , Figure 5 yes Figure 4 The schematic diagram of a partial structure of the rotary kiln shown illustrates that, in Figure 5To clearly illustrate the structure of the spiral guide plate, the lifting plate 140 in the rotary kiln tube 11 is not shown. In an optional embodiment, the number of spiral turns of the first spiral guide plate 12 and the second spiral guide plate 13 are both greater than one, and the pitch d1 of the first spiral guide plate 12 is greater than or equal to the pitch d2 of the second spiral guide plate 13. Both the first spiral guide plate 12 and the second spiral guide plate 13 can be multi-turn spiral structures. The pitch of the spiral guide plate is a key parameter that determines the axial conveying speed of the material. Generally, the larger the pitch, the stronger the propulsive effect on the material, resulting in a correspondingly shorter residence time of the material in a specific section.
[0037] Since the first spiral guide plate 12 is located close to the feed inlet, it can also be called the furnace head spiral guide plate. The function of the first spiral guide plate 12 is to achieve rapid material introduction and initial distribution, preventing material accumulation at the furnace head. Therefore, the first spiral guide plate 12 can have a larger pitch and more spiral turns to generate strong axial thrust, causing the material to quickly leave the feed zone w2. In contrast, multiple second spiral guide plates 13 are spaced apart in the middle and rear sections of the furnace tube. The function of the second spiral guide plates 13 is to finely control the material's propulsion speed and residence time in the main reaction zone. Therefore, the pitch d2 of the second spiral guide plates 13 can be less than or equal to the pitch d1 of the first spiral guide plates 12, achieving a gentler and more controllable conveying, ensuring sufficient processing time for the material in the heating or reaction zone.
[0038] In one exemplary embodiment, the pitch of the spiral guide plate can be set according to the material's flowability; the better the material's flowability, the smaller the pitch can be designed. Simultaneously, the spiral angle c1 of the spiral guide plate must be greater than half the material's angle of repose to ensure that the spiral guide plate can effectively grasp and push the material, thereby achieving forced material conveying. Here, the spiral angle refers to the angle between the spiral tangent direction and the direction of the spiral blade cross-section.
[0039] Please continue to refer to this. Figure 5 In the radial direction of the rotary kiln tube 11, the plate height h1 of the first spiral guide plate 12 is greater than the plate height h2 of the second spiral guide plate 13. Because the first spiral guide plate 12 has a larger pitch and plate height, the resulting thread is deeper and the lead is longer during rotation, allowing for the pushing of more material at once and achieving rapid material feeding. In contrast, the second spiral guide plate 13 has a smaller pitch d2 and plate height, resulting in more precise material constraint and a gentler feeding speed. The plate height refers to the radial vertical distance from the inner wall surface of the rotary kiln tube 11 to the outer edge of the top of the spiral guide plate blades; in other words, the plate height is the height of the spiral blades protruding inside the kiln tube.
[0040] In this way, a fast-to-slow conveying rhythm can be achieved. The first spiral guide plate 12 first ensures smooth feeding and prevents blockage. The subsequent second spiral guide plate 13 regulates the overall movement speed of the material in the furnace to avoid insufficient reaction caused by excessive material conveying. Thus, while increasing production capacity, the required residence time for the reaction can be guaranteed.
[0041] When the height of the spiral guide plate is less than the thickness of the material layer inside the furnace, some material will directly overturn the spiral guide plate without being hindered or pushed by the spiral. Therefore, the higher the plate, the stronger its hindering or pushing effect on the material, thus better controlling the residence time of the material in that area. However, when the plate height is greater than the material layer thickness, the material will never be able to overturn the spiral plate, and its impact on the material residence time will tend to be gradual. Further increasing the height of the spiral plate will increase material costs. Therefore, the plate height is greater than the material layer thickness corresponding to a 20% furnace tube filling rate to ensure that the spiral guide plate can effectively act on the material and produce a stable conveying effect.
[0042] Please refer to Figure 3 and Figure 4 In one optional embodiment, the plurality of second spiral guide plates 13 may include a plurality of in-furnace spiral guide plates 131 and at least one tail spiral guide plate 132, and the other end of the rotary furnace tube 11 has a discharge port k2; the plurality of in-furnace spiral guide plates 131 are installed at intervals along the axial direction of the rotary furnace tube 11 on the inner wall of the rotary furnace tube 11; the tail spiral guide plate 132 is located on the side of the plurality of in-furnace spiral guide plates 131 facing the discharge port k2; wherein, the pitch of the tail spiral guide plate 132 is greater than or equal to the pitch of the in-furnace spiral guide plates 131.
[0043] When the material passes through the furnace zone, it is controlled by the furnace spiral guide plate 131 with a smaller pitch, which slows down the material movement and prolongs the residence time in the main reaction zone. After reaching the furnace tail zone, it is replaced by the furnace tail spiral guide plate 132 with a larger pitch, which increases the axial thrust on the material and speeds up the material movement.
[0044] In this way, by slowing down the reaction in the middle section of the furnace where full reaction is required and speeding up the reaction in the tail section where timely discharge is required, it can be ensured that the material has enough time to complete the reaction in the high-temperature reaction zone. At the same time, the material that has completed the reaction can be discharged quickly to prevent over-reaction or accumulation, thereby improving product quality and production efficiency.
[0045] Please refer to Figure 3 , Figure 4 and Figure 6 , Figure 6This is an exploded structural diagram of a rotary kiln provided in an embodiment of this application. In an optional embodiment, the number of spiral turns of the first spiral guide plate 12 is greater than or equal to the number of spiral turns of the second spiral guide plate 13, and the number of spiral turns of the tail spiral guide plate 132 is greater than the number of spiral turns of the in-furnace spiral guide plate 131. Since a greater number of spiral turns indicates that the spiral structure of the spiral guide plate is longer in the axial direction, the first spiral guide plate 12 and the tail spiral guide plate 132 have more turns, making their axial pushing effect on the material more sustained and stable. Thus, the longer working range of the first spiral guide plate 12 ensures smooth feeding; the longer working range of the tail spiral guide plate 132 ensures thorough discharge, which can strengthen the conveying guarantee of key nodes (i.e., the feeding zone w2 and the discharge zone w3). For example, the number of turns of the spiral guide plate 132 at the furnace tail is 0.5 more than the number of turns of the spiral guide plate 131 in the furnace, which can more effectively push the material to the discharge port k2 and avoid material accumulation at the furnace tail.
[0046] Please refer to Figure 3 and Figure 4 In an optional embodiment, the rotary kiln may further include multiple lifting plate groups 14, each lifting plate group 14 including multiple lifting plates 140. The multiple lifting plate groups 14 are fixed at intervals along the axial direction of the rotary kiln tube 11 on the inner wall of the rotary kiln tube 11, and the multiple lifting plates 140 in each lifting plate group 14 are arranged at intervals along the axial direction of the rotary kiln tube 11. The lifting plate groups 14 and the second spiral guide plate 13 are alternately arranged along the axial direction of the rotary kiln tube 11. By setting multiple lifting plates 140 at the furnace head, furnace middle and furnace tail positions in the rotary kiln tube 11, and setting the lifting angle according to the material flowability, the material is more thoroughly turned over and mixed in the furnace tube, thereby improving production efficiency.
[0047] Each lifting plate group 14 includes multiple lifting plate subgroups. Each lifting plate group includes multiple lifting plates 140 arranged circumferentially along the rotary kiln tube 11. The multiple lifting plate groups in each lifting plate group 14 are arranged axially along the rotary kiln tube 11, and the lifting plates 140 in two adjacent lifting plate groups are alternately arranged (i.e., staggered) in the axial direction of the rotary kiln tube 11.
[0048] In this embodiment, the spiral guide plates and the lifting plate assembly 14 are arranged alternately in the axial direction. The spiral guide plates are used to control the axial movement speed of the material. The lifting plate assembly 14, located between the two spiral guide plates, is used to lift and scatter the material from the bottom when the furnace tube rotates, forming a material curtain to achieve mixing and heat exchange of the material in the radial cross section. In this way, the alternating arrangement can achieve decoupling and synergy between the axial conveying and radial mixing of the material movement. It can avoid insufficient mixing caused by using only spiral guide plates, and it can also avoid axial speed runaway caused by using only lifting plates 140, thereby simultaneously improving the uniformity of material reaction and the controllability of the production process.
[0049] Please refer to Figure 3 and Figure 4 In one optional embodiment, the plurality of lifting plate groups 14 are at least divided into a furnace head lifting plate group 141, a furnace middle lifting plate group 142, and a furnace tail lifting plate group 143, with a discharge port k2 at the other end of the rotary furnace tube 11; the furnace head lifting plate group 141 is located on the side of the first spiral guide plate 12 away from the feed port and is arranged adjacent to the first spiral guide plate 12; the furnace tail lifting plate group 143 is arranged adjacent to the discharge port k2; and the furnace middle lifting plate group 142 is located between the furnace head lifting plate group 141 and the furnace tail lifting plate group 143. By setting lifting plate groups 14 in three functional sections—furnace head, furnace middle, and furnace tail—the furnace head lifting plate group 141 can gently agitate the material when it first enters; the furnace middle lifting plate group 142 agitates the material vigorously in the core reaction zone; and the furnace tail lifting plate group 143 can assist in the directional movement of the material before the outlet. This enables segmented specialization of the lifting function. Each zone's feed plate 140 can be independently optimized to meet the specific needs of that zone (such as dust prevention, strong mixing, and accelerated discharge), thereby improving the applicability of the rotary kiln.
[0050] Please refer to Figure 3 , Figure 4 , Figure 7 , Figure 8 , Figure 9 and Figure 10 , Figure 7 yes Figure 2 The diagram shows another structural view of the rotary kiln. Figure 8 yes Figure 7 The diagram shown is a cross-sectional structure of a rotary kiln along the B1-B2 position. Figure 9 yes Figure 7 The diagram shown is a cross-sectional view of the rotary kiln along the C1-C2 position. Figure 10 yes Figure 7 The diagram shows a cross-sectional structure of the rotary kiln along position D1-D2. In an optional embodiment, the radial deflection angle c2 of the lifting plate in the furnace head lifting plate group 141 is greater than or equal to the radial deflection angle c3 of the lifting plate in the furnace middle lifting plate group 142 and the radial deflection angle c4 of the lifting plate in the furnace tail lifting plate group 143. The radial deflection angle is the angle between the intersection line formed by the intersection of the plate surface of the lifting plate 140 and the first plane and the tangent in the rotation direction of the rotary kiln tube 11. The first plane is a plane perpendicular to the axis of the rotary kiln tube 11.
[0051] Among them, the lifting plate in the furnace head lifting plate group 141 can be called the furnace head lifting plate 1411, the lifting plate in the furnace middle lifting plate group 142 can be called the furnace middle lifting plate 1421, and the lifting plate in the furnace tail lifting plate group 143 can be called the furnace tail lifting plate 1431.
[0052] The multiple lifting plates 140 in the rotary furnace tube 11 are divided into the furnace head lifting plate group 141, the furnace middle lifting plate group 142 and the furnace tail lifting plate group 143 according to their axial positions. Different parameter settings are adopted to achieve differentiated control of the material turning behavior in the furnace. Among them, the radial deflection angle can be used as one of the important control parameters. The radial deflection angle is defined as the angle between the orthographic projection of the lifting plate 140 on the plane perpendicular to the axis of the rotary furnace tube 11 and the tangent of the rotation direction of the rotary furnace tube 11 in the plane.
[0053] In this embodiment, the effect of radial deflection angle on material tumbling can be obtained through the following experimental tests. Please refer to [reference needed]. Figure 11 , Figure 12 , Figure 13 , Figure 14 , Figure 15 and Figure 16 , Figure 11 This is a schematic diagram of the structure of a material-lifting plate 140 with a radial deflection angle of 135° provided in an embodiment of this application. Figure 12 This is a schematic diagram of the structure of a feeding plate 140 with a radial deflection angle of 90° provided in an embodiment of this application. Figure 13 This is a schematic diagram of the structure of a feeding plate 140 with a radial deflection angle of 45° provided in an embodiment of this application. Figure 14 yes Figure 11 The diagram shows the simulation results of the material lifting plate 140 with a radial deflection angle of 135°. Figure 15 yes Figure 12 The diagram shows the simulation results of the material lifting plate 140 with a radial deflection angle of 90°. Figure 16 yes Figure 13 The diagram shown illustrates the simulation results of the lifting plate 140 with a radial deflection angle of 45°. This simulation result can be a schematic diagram obtained based on simplified fluid analogy analysis. In the diagram, the black arrow indicates the rotation direction z1 of the rotary kiln body. Simulation analysis shows that the size of the radial deflection angle affects the material-holding capacity and throwing height of the lifting plate 140—the larger the deflection angle, the easier it is for the material to slip, resulting in a lower throwing height and gentler material mixing; the smaller the deflection angle, the higher the material is lifted, resulting in more intense throwing and more thorough material mixing.
[0054] Please refer to the following: Figure 17 , Figure 18 , Figure 19 , Figure 20 , Figure 21 and Figure 22 , Figure 17 yes Figure 11 The diagram shown illustrates the actual operation of the lifting plate 140 with a radial deflection angle of 135°. Figure 18 yes Figure 12 The diagram shown illustrates the actual operation of the lifting plate 140 with a radial deflection angle of 90°. Figure 19 yes Figure 13 The diagram shown illustrates the actual operation of the lifting plate 140 with a radial deflection angle of 45°. Figure 20 yes Figure 11 The diagram shows the dust emission test results for a material lifting plate 140 with a radial deflection angle of 135°. Figure 21 yes Figure 12 The diagram shows the dust emission test results for a material lifting plate 140 with a radial deflection angle of 90°. Figure 22 yes Figure 13 The diagram shows the dust emission test results for a material lifting plate 140 with a radial deflection angle of 45°. The results are obtained through... Figures 17 to 19 The lifting height can be observed, that is, the maximum falling height of the material after it is thrown can be observed inside the simulated rotating drum equipped with lifting plates 140. Figures 20 to 22 The degree of dust can be observed by sealing white paper at both ends of a simulated rotating drum and comparing the dust adhesion area and density on the white paper surface. The experimental results of the material lifting effect of the feeding plate 140 with different radial deflection angles are shown in Table 1 below.
[0055] Table 1
[0056] Based on the above experimental results, in this embodiment, the radial deflection angle c2 of the furnace head lifting plate 1411 is greater than or equal to the radial deflection angle c3 of the furnace middle lifting plate 1421, and the radial deflection angle c2 of the furnace head lifting plate 1411 is greater than or equal to the radial deflection angle c4 of the furnace tail lifting plate 1431. Since the rotary kiln also includes an exhaust system in the furnace head area, a larger radial deflection angle, such as 145° or 135°, is used in the furnace head area to achieve gentle turning with low dust emission, avoiding losses caused by large amounts of newly fed material being drawn away by the exhaust system, while simultaneously completing the initial distribution of materials. In the furnace middle area, which bears the core reaction, a smaller radial deflection angle, such as 100° or 90°, is used to form a vigorous mixing with high dispersion, greatly increasing the contact area and frequency between the material and the heat medium, ensuring a uniform and sufficient reaction. Thus, by setting the radial deflection angle of the lifting plate 140° according to the functional section differences, it is possible to improve reaction uniformity and production efficiency while also achieving precise control over energy consumption and material loss.
[0057] Please refer to Figure 23 , Figure 23This is a partial cross-sectional structural diagram of a rotary kiln provided in an embodiment of this application. In an optional embodiment, the radial deflection angle of the lifting plate in the tail lifting plate group 143 (i.e., the tail lifting plate 1431) is less than or equal to the radial deflection angle of the lifting plate in the in-furnace lifting plate group 142 (i.e., the in-furnace lifting plate 1421). At least some of the working surfaces of the lifting plates 140 in the tail lifting plate group 143 have an acute angle with the rotation axis z2 of the rotary kiln tube 11, and the opening of the acute angle faces the discharge port k2. In other words, the tail lifting plate group... The orthographic projection of the working surface of at least a portion of the lifting plates 140 in the furnace tail assembly 143 onto the inner wall of the rotary furnace tube forms an acute angle with the rotation axis z2, such that when at least a portion of the lifting plates 140 in the furnace tail assembly 143 rotates to the sides of the rotation axis z2 in the horizontal direction, the lower side of the working surface faces the discharge port k2. This acute angle can be referred to as the axial tilt angle c5. At least a portion of the lifting plates 140 in the furnace head assembly 141 and at least a portion of the lifting plates 140 in the furnace middle assembly 142 are parallel to the rotation axis z2 of the rotary furnace tube 11. For example, the furnace tail lifting plate 1431 can adopt a small radial deflection angle, such as 90° or 75°.
[0058] It is understood that the aforementioned working plate surface refers to the main plane on the lifting plate that directly contacts the material and primarily undertakes the functions of lifting and guiding. Because the working plate surface of the tail lifting plate 1431 is inclined relative to the rotation axis z1, when the rotary furnace tube 11 rotates, regardless of the position of the tail lifting plate 1431 on the circumference, this fixed inclination direction allows the tail lifting plate 1431 to provide the material with a component force towards the discharge port.
[0059] Thus, in the tail area, setting the radial deflection angle c4 of the tail lifting plate 1431 to be less than or equal to that of the lifting plate 1421 in the furnace can prevent material from easily sliding radially off the tail lifting plate 1431, making it easier for the material caught by the lifting plate 140 to be constrained near the plate surface, thereby providing a stable basis for subsequent axial guidance. Under this premise, the axial tilt angle c5 (the acute angle formed by the working plate surface and the rotation axis z2) set on the tail lifting plate 1431 can play a full role: when the tail lifting plate 1431 grabs the material and lifts it, the material will slide and accelerate steadily along the inclined plate surface (towards the discharge port k2) under the action of gravity.
[0060] Thus, a smaller radial deflection angle can reduce the radial slippage of materials, ensuring that more materials can be effectively captured and enter the axially guided process; the axial tilt angle c5 can apply a clear and continuous axial thrust to these constrained materials; the combination of the two can form a synergistic pushing effect of first constraining and then directional pushing of materials, which can significantly improve the discharge speed.
[0061] The axial tilt angle c5 can be greater than or equal to 1 / 2 the angle of repose of the material being processed to ensure effective overcoming of internal friction and generate a reliable forced conveying effect. This solves the problem of material accumulation at the furnace tail in related technologies, ensuring that the reacted material can be discharged quickly and completely, thus improving the continuity of equipment operation and production capacity.
[0062] In one exemplary embodiment, the axial tilt angle c5 can range from 10° to 45°. For example, the axial tilt angle c5 can range from 10°, 20°, 30°, or 45°. The radial deflection angle c2 of the furnace head lifting plate 1411 can range from 100° to 145°. For example, the radial deflection angle c2 of the furnace head lifting plate 1411 is 145°, 135°, 120°, or 110°. The radial deflection angle c3 of the furnace middle lifting plate 1421 can range from 70° to 110°. For example, the radial deflection angle c3 of the furnace middle lifting plate 1421 is 100°, 95°, 90°, or 80°. The radial deflection angle c4 of the furnace tail lifting plate 1431 can range from 60° to 100°. For example, the radial deflection angle c4 of the furnace tail lifting plate 1431 is 90°, 75°, 60°, or 45°.
[0063] Please refer to Figure 4 In one optional embodiment, along the circumference of the rotary furnace tube 11, the distribution density of the lifting plates in the lifting plate group 142 in the furnace is greater than or equal to the distribution density of the lifting plates in the furnace head lifting plate group 141; the distribution density of the lifting plates in the furnace head lifting plate group 141 is greater than or equal to the distribution density of the lifting plates in the furnace tail lifting plate group 143. It is understood that the distribution density of the lifting plates 140 can refer to the number of lifting plates 140 in each lifting plate subgroup, and the lifting plates 140 in each lifting plate subgroup can be evenly arranged along the circumference of the rotary furnace tube 11.
[0064] The distribution density of the lifting plates 140 affects the frequency of material being lifted and scattered per unit time, thus influencing the intensity of radial mixing and the material residence time. A higher distribution density of the lifting plates 140 results in a denser material curtain and more intense mixing. Therefore, using a higher distribution density of the lifting plates 140 in the middle section of the furnace, which bears the core reaction function, allows for sufficient material agitation and heat exchange, ensuring uniform reaction. A medium distribution density in the furnace head section achieves necessary initial mixing while suppressing excessive dust and material loss due to over-scattering. A minimum distribution density in the furnace tail section reduces interference from the lifting action on the axial discharge of the material, allowing for rapid material discharge.
[0065] Because the residence time of materials in the rotary kiln has a significant impact on the process effect, firstly, residence time directly affects the integrity of the reaction process. For chemical reactions such as calcination and roasting, or physical processes such as drying and phase change, sufficient residence time must be ensured to allow the reaction to proceed fully and thus meet the quality requirements of the product in terms of activity, purity, or loss on ignition. Secondly, residence time is closely related to production efficiency. Under the premise of ensuring product quality, excessive residence time will reduce the material throughput, thereby limiting the equipment's capacity. Thirdly, residence time is also closely coupled with energy consumption. A reasonable residence time allows for more efficient heat exchange between the material and the hot gas flow, avoiding insufficient heat transfer due to insufficient time or waste of heat energy due to excessive time. Therefore, when setting up the spiral guide plate and the lifting plate 140, the combined impact of both on the material residence time should be systematically considered, and precise control of the residence time should be achieved through the coordinated design of their structural parameters.
[0066] Based on the above principles, in the embodiments of this application, the following relationships can be satisfied between the furnace head spiral guide plate (i.e., the first spiral guide plate 12), the furnace middle guide plate, and the furnace tail guide plate: the pitch of the furnace head spiral guide plate ≥ the pitch of the furnace tail spiral guide plate 132 ≥ the pitch of the furnace middle spiral guide plate 131; the plate height of the furnace head spiral guide plate > the plate height of the furnace middle spiral guide plate 131 = the plate height of the furnace tail spiral guide plate 132.
[0067] The following relationships can be satisfied between the furnace head lifting plate 1411, the furnace middle lifting plate 1421, and the furnace tail lifting plate 1431: the radial deflection angle c2 of the furnace head lifting plate 1411 ≥ the radial deflection angle c3 of the furnace middle lifting plate 1421 ≥ the radial deflection angle c4 of the furnace tail lifting plate 1431; the density of the furnace middle lifting plate 1421 ≥ the density of the furnace head lifting plate 1411 ≥ the density of the furnace tail lifting plate 1431.
[0068] In one exemplary embodiment, taking a rotary kiln with a processing capacity of 30 tons (30T) as an example, the specific parameter configurations of its internal spiral guide plate and lifting plate 140 are as follows. Among them, the key structural parameters of the spiral guide plate are shown in Table 2, and the key structural parameters of the lifting plate 140 are shown in Table 3.
[0069] Table 2
[0070] Table 3
[0071] In Table 2, "r" represents the radius of the rotary furnace tube 11, and the multiple furnace zones include the feeding zone w2, multiple process temperature zones w1, and the discharge zone w3. Experimental tests show that, based on the above parameter configuration, the furnace head spiral guide plate, with its larger pitch (400mm) and more turns (2.5 turns), can strongly push the feed axially, thus preventing material accumulation at the furnace head and ensuring rapid material entry into the heating zone. The furnace middle spiral guide plate 131 uses a smaller pitch (240mm) to precisely control the axial movement speed of the material in the core heating zone, thereby accurately controlling the material residence time and ensuring sufficient reaction. The furnace tail spiral guide plate 132, while maintaining the same pitch (240mm) as the furnace middle plate, increases the number of spiral turns (2.0 turns), which extends the axial action range of the furnace tail spiral guide plate 132 on the material, allowing for more thorough material pushing out of the reaction zone while controlling the residence time.
[0072] The furnace head lifting plate 1411 employs a larger radial deflection angle (135°) and a lower distribution density (12 plates / revolving ring), which reduces dust generation and minimizes material loss due to being carried away by the exhaust system while achieving necessary turning. The furnace middle lifting plate 1421 employs a smaller radial deflection angle (90°) and a higher distribution density (16 plates / revolving ring), enabling vigorous and frequent scattering, promoting radial mixing and heat exchange of materials, and improving reaction efficiency and uniformity. The furnace tail lifting plate 1431, while maintaining a 90° radial deflection angle for appropriate turning, also features a 20° axial tilt angle c5, with the lower side of the plate facing the discharge port k2. This allows the furnace tail lifting plate 1431 to provide a clear axial thrust to the material pointing towards the discharge port k2 during rotation, thereby achieving rapid and thorough material discharge and effectively preventing material accumulation at the furnace tail.
[0073] In summary, this embodiment of the application solves problems such as material accumulation, uneven reaction, and low production efficiency by segmenting spiral guide plates and lifting plates 140 with different structural parameters within the rotary kiln tube 11 and arranging them alternately and collaboratively in the axial direction. Specifically, by setting a first spiral guide plate 12 with a larger pitch and plate height at the beginning of the furnace head, rapid material introduction and forced conveying can be achieved, avoiding material accumulation at the feed inlet and ensuring initial uniform distribution and smooth conveying of materials within the furnace tube. Furthermore, by setting a second spiral guide plate 13 with a smaller pitch in the furnace and at the furnace tail region, the axial movement speed and residence time of materials in each process section can be precisely controlled. Simultaneously, the lifting plates 140 with a small radial deflection angle and high distribution density in the furnace region enhance radial mixing and heat exchange of materials, ensuring uniform heating and sufficient reaction, thereby improving product quality consistency.
[0074] Furthermore, by employing a large radial deflection angle and low distribution density lifting plate 140 at the furnace head, necessary turning is achieved while suppressing dust loss. An axial tilt angle c5 is added to the lifting plate 140 at the furnace tail, pointing towards the discharge port k2, giving it an active guiding discharge function and solving the problem of material accumulation at the tail end. Thus, through differentiated design for each functional area, mixing and reaction efficiency are improved while ensuring smooth and stable material flow, thereby enhancing the overall capacity and operational continuity of the rotary kiln.
[0075] It should be noted that the dimensions of the areas may have been exaggerated in the accompanying drawings for clarity. Furthermore, it is understood that when an element is referred to as "on top of" another element, it can be directly on the other element, or there may be intermediate elements. Additionally, it is understood that when an element is referred to as "below" another element, it can be directly below the other element, or there may be more than one intermediate element. Furthermore, it is also understood that when an element is referred to as "between" two elements, it can be the only layer between the two elements, or there may be more than one intermediate element. Similar reference numerals throughout indicate similar elements.
[0076] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.
[0077] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.
Claims
1. A rotary kiln, characterized in that, The rotary kiln includes: A rotary furnace tube, one end of which has a feed inlet; The first spiral guide plate is installed on the inner wall of the rotary kiln tube and is arranged adjacent to the feed port; Multiple second spiral guide plates are installed at intervals along the axial direction of the rotary kiln tube on the inner wall of the rotary kiln tube, and are all located on the side of the first spiral guide plate away from the feed inlet.
2. The rotary kiln according to claim 1, characterized in that, The number of spiral turns of the first spiral guide plate and the number of spiral turns of the second spiral guide plate are both greater than one, and the pitch of the first spiral guide plate is greater than or equal to the pitch of the second spiral guide plate. In the radial direction of the rotary kiln tube, the height of the first spiral guide plate is greater than the height of the second spiral guide plate.
3. The rotary kiln according to claim 1, characterized in that, The plurality of second spiral guide plates include a plurality of in-furnace spiral guide plates and at least one furnace tail spiral guide plate, and the other end of the rotary furnace tube has a discharge port; The plurality of in-furnace spiral guide plates are installed at intervals along the axial direction of the rotary furnace tube on the inner wall of the rotary furnace tube; The furnace tail spiral guide plate is located on the side of the plurality of furnace spiral guide plates facing the discharge port; Wherein, the pitch of the spiral guide plate at the tail of the furnace is greater than or equal to the pitch of the spiral guide plate in the furnace.
4. The rotary kiln according to claim 3, characterized in that, The number of spiral turns of the first spiral guide plate is greater than or equal to the number of spiral turns of the second spiral guide plate, and the number of spiral turns of the furnace tail spiral guide plate is greater than the number of spiral turns of the furnace middle spiral guide plate.
5. The rotary kiln according to claim 1, characterized in that, The rotary kiln also includes multiple lifting plate groups, each lifting plate group including multiple lifting plates. The multiple lifting plate groups are fixed at intervals along the axial direction of the rotary kiln tube on the inner wall of the rotary kiln tube, and the multiple lifting plates in each lifting plate group are arranged at intervals along the axial direction of the rotary kiln tube. The feeding plate assembly and the second spiral guide plate are alternately arranged in the axial direction of the rotary kiln tube.
6. The rotary kiln according to claim 5, characterized in that, The plurality of lifting plate groups are at least divided into a furnace head lifting plate group, a furnace middle lifting plate group and a furnace tail lifting plate group, and the other end of the rotary furnace tube has a discharge port; The furnace head feeding plate assembly is located on the side of the first spiral guide plate away from the feed inlet and is arranged adjacent to the first spiral guide plate; The tail-end material-lifting plate group is arranged adjacent to the discharge port; The furnace lifting plate group is located between the furnace head lifting plate group and the furnace tail lifting plate group.
7. The rotary kiln according to claim 6, characterized in that, The radial deflection angle of the lifting plate in the furnace head lifting plate group is greater than or equal to the radial deflection angle of the lifting plate in the furnace middle lifting plate group and the radial deflection angle of the lifting plate in the furnace tail lifting plate group. Wherein, the radial deflection angle is the angle between the intersection line formed by the intersection of the surface of the feeding plate and the first plane and the tangent of the rotation direction of the rotary furnace tube, and the first plane is a plane perpendicular to the axis of the rotary furnace tube.
8. The rotary kiln according to claim 6, characterized in that, The radial deflection angle of the lifting plate in the tail of the furnace is less than or equal to the radial deflection angle of the lifting plate in the furnace. At least some of the lifting plates in the tail of the furnace have an acute angle between their working surfaces and the rotation axis of the rotary furnace tube, and the opening of the acute angle faces the discharge port. At least some of the lifting plates in the furnace head lifting plate group and at least some of the lifting plates in the furnace lifting plate group are parallel to the rotation axis of the rotary furnace tube.
9. The rotary kiln according to claim 6, characterized in that, Along the circumference of the rotary furnace tube, the distribution density of the lifting plates in the furnace lifting plate group is greater than or equal to the distribution density of the lifting plates in the furnace head lifting plate group. The distribution density of the lifting plates in the furnace head lifting plate group is greater than or equal to the distribution density of the lifting plates in the furnace tail lifting plate group.
10. The rotary kiln according to claim 6, characterized in that, The rotary furnace tube has multiple process temperature zones and multiple heating components arranged along the axial direction of the rotary furnace tube, and the multiple heating components are respectively used to heat the multiple process temperature zones; The second spiral guide plate is located at the separation position between adjacent process temperature zones inside the rotary furnace tube.