Rotary furnace

Abstract

The invention relates to a rotary furnace, and belongs to the field of calcining equipment, the rotary furnace comprises a furnace tube body, a heating assembly, a protection piece and a connecting assembly, the heating assembly is distributed on the inner circumferential wall of the furnace tube body, the heating assembly is electrically connected to the furnace tube body through the connecting assembly, and the protection piece is arranged on the furnace tube body. The protection piece surrounds the periphery of the heating assembly and is fixedly connected with the inner wall of the furnace tube body; and the protection piece is made of a heat-conducting and wear-resistant material. In the working process of the rotary furnace, under the action of the connecting assembly, the heating assembly directly transfers heat into the furnace tube, so that the contact temperature of the furnace tube body is reduced, and the possibility of damage to the furnace tube body is reduced; and the furnace tube body is not in direct contact with the material, so that the possibility that metal components in the furnace tube body pollute materials such as a lithium battery anode material is reduced. In addition, due to the existence of the protection piece, the materials cannot make contact with the heating assembly, and the heating assembly can play a role for a long time.

Description

Technical Field

[0001] The present application relates to the field of calcining equipment, and in particular to a rotary kiln. Background Art

[0002] Lithium batteries are secondary batteries that use the migration of lithium ions between the positive and negative electrodes to achieve the charging and discharging process. Lithium batteries have high energy density, long cycle life and low self-discharge rate, so they are widely used in mobile electronic devices, electric vehicles and energy storage systems. The positive and negative electrode materials of lithium batteries must be roasted in a high-temperature kiln during the preparation process. Rotary kilns are widely used in the preparation of lithium battery materials because they can achieve continuous production, the same furnace can control the temperature in multiple temperature zones, and the heating is uniform.

[0003] The process temperature required for preparing lithium battery materials is about 800-1000℃, or even higher, so the temperature inside the rotary kiln must reach about 800-1000℃. Since the heating source of the rotary kiln is usually outside the metal furnace tube, the heat of the heating source is first transferred to the metal furnace tube, and then from the metal furnace tube to the heated object. Therefore, the temperature provided by the heating source, that is, the temperature of the metal furnace tube, must be higher than this temperature, resulting in that the rotary furnace tube made of ordinary metal cannot be used normally (most steels will soften and creep when the temperature is higher than 500-800℃, and the mechanical strength will be greatly reduced as the temperature rises). Summary of the invention

[0004] In order to enable the rotary kiln to function effectively in a high temperature environment, the present application provides a rotary kiln.

[0005] The present application provides a rotary kiln, which adopts the following technical solution: A rotary kiln includes a furnace tube body, a heating component, a protective component and a connecting component. The heating component is distributed on the inner circumferential wall of the furnace tube body. The heating component is electrically connected to the furnace tube body through the connecting component. The protective component surrounds the outer circumference of the heating component and is fixedly connected to the inner wall of the furnace tube body. The protective component is made of heat-conducting and wear-resistant material.

[0006] Optionally, the protective member is a cylinder with a placement groove, and the side of the protective member with the placement groove is connected to the furnace tube body; the placement groove is used to accommodate the heating component.

[0007] Optionally, the heating component includes a plurality of heating wires arranged around the inner wall of the furnace tube, and each of the heating wires is electrically connected to an external power source through the connecting component.

[0008] Optionally, the connection assembly includes a first collector and a second collector, the first collector includes a first conductive ring, a second conductive ring, a metal cylinder and a brush, the first conductive ring is sleeved on the outer wall of the furnace tube body and is rotatably connected to the furnace tube body, the metal cylinder is sleeved on the outer wall of the furnace tube body, one end of the metal cylinder is fixedly connected to the first conductive ring, and the other end is rotatably connected to the second conductive ring, the second conductive ring is sleeved on the outer wall of the furnace tube body and is fixedly connected to the furnace tube body; one end of the brush is connected to the first conductive ring, and the other end is abutted against the second conductive ring; the first conductive ring and the second conductive ring are both provided with conductive terminals; The second current collector includes an insulating plate and a conductive plate. The insulating plate is sleeved on the outer wall of the furnace tube body and fixedly connected to the furnace tube body. The conductive plate is fixedly connected to a side of the insulating plate away from the furnace tube body. The outer wall of the conductive plate is provided with a conductive terminal.

[0009] Optionally, the heating components are arranged in parallel.

[0010] Optionally, the protective member is made of ceramic, silicon nitride ceramic shell, aluminum oxide ceramic, zirconium oxide ceramic, silicon carbide ceramic or glass fiber.

[0011] Optionally, the inner wall of the furnace tube body is connected to a heat-insulating layer, and the heating component is located on a side of the heat-insulating layer away from the inner wall of the furnace tube body.

[0012] Optionally, the material of the thermal insulation layer is a high-aluminum mullite refractory material, a corundum mullite refractory material and / or a silicon carbide refractory material.

[0013] Optionally, a stirring member is connected to the outer wall of the protective member.

[0014] Optionally, the stirring member includes a connecting plate, a reinforcement plate and a material lifting plate, the connecting plate is fitted with the outer wall of the protective member and fixedly connected to the protective member, one side of the reinforcement plate is fixedly connected to the connecting plate, and the other end is fixedly connected to the material lifting plate, and the end of the material lifting plate coincides with the end of the reinforcement plate.

[0015] In summary, this application includes the following beneficial technical effects: (1) During the operation of the rotary kiln, the heating component directly transfers heat to the inside of the furnace tube under the action of the connecting component, so that the contact temperature of the furnace tube body is reduced, which helps to reduce the possibility of affecting or even damaging the furnace tube body; (2) The furnace tube body is no longer in direct contact with the material, reducing the possibility of metal components in the furnace tube body contaminating materials such as lithium battery anode materials; (3) The presence of the protective part prevents the material from directly contacting the heating component, which helps the heating component to function for a long time; (4) Each heating component is connected in parallel. During normal operation, the temperature of the entire furnace can be controlled by controlling each heating component individually. Even if some heating components are damaged, the heating process will not be seriously affected. The working process of the rotary kiln is stable and reliable. (5) The heating component is installed in the placement slot, which makes maintenance convenient and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of a rotary kiln in an embodiment of the present application; Figure 2 It is a schematic diagram of a partial longitudinal section of a rotary kiln in an embodiment of the present application; Figure 3 It is a schematic diagram highlighting the planar structure of a first current collector in a rotary furnace according to an embodiment of the present application; Figure 4 is a schematic diagram highlighting the three-dimensional structure of a second current collector in a rotary furnace according to an embodiment of the present application; Figure 5 It is a schematic diagram highlighting the three-dimensional structure of a stirring element in a rotary kiln according to an embodiment of the present application.

[0017] Explanation of the accompanying drawings: 1. furnace tube body; 2. heating component; 3. protective part; 31. placement groove; 4. connecting component; 41. first collector; 411. first conductive ring; 412. second conductive ring; 413. metal cylinder; 414. brush; 42. second collector; 421. insulating plate; 422. conductive plate; 5. insulation layer; 6. stirring part; 61. connecting plate; 62. reinforcement plate; 63. lifting plate. DETAILED DESCRIPTION

[0018] The present application is further described in detail with reference to the following examples. It should be noted that if no specific conditions are specified in the following examples, the conventional conditions or the conditions recommended by the manufacturer are followed, and the raw materials used in the following examples can be obtained from common commercial sources unless otherwise specified.

[0019] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0020] In the present application, “first”, “second”, “third”, etc. are only used for the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0021] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0022] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0023] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application. The terms used in this application and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more related listed items. The term "multiple" in this application means at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0024] The present application embodiment discloses a rotary kiln. Figure 1 The rotary kiln includes a furnace tube body 1, a heating component 2, a protective component 3 and a connecting component 4. The heating component 2 is distributed on the inner wall of the furnace tube body 1. The heating component 2 is electrically connected to the furnace tube body 1 through the connecting component 4. The protective component 3 surrounds the outer periphery of the heating component 2 and is fixedly connected to the inner wall of the furnace tube body 1; the protective component 3 is made of heat-conducting and wear-resistant materials.

[0025] It should be noted that the rotary furnace also includes a support, and the furnace tube body 1 is rotatably connected to the support through a bearing, and the furnace tube body 1 rotates around the central axis in the length direction. The material of the furnace tube body 1 can be Q235 steel, or any one of Q255 steel, 45# steel or 304 steel, etc., which can be selected according to actual conditions, and this embodiment does not specifically limit this.

[0026] In order to promote the heat preservation effect and further protect the furnace tube body 1, the Figure 1 and Figure 2As shown, the inner wall of the furnace tube body 1 is bonded with an insulation layer 5, and the heating component 2 is located on the side of the insulation layer 5 away from the inner wall of the furnace tube body 1. In other specific embodiments, the insulation layer 5 is connected to the furnace tube body 1 by rivets, and the rivets are selected from one or more of mushroom rivets, T-shaped rivets, Y-shaped rivets, etc. At this time, the rivets can be welded to the inner wall of the furnace tube body 1 in a staggered and uniform manner at 10-15 circles per square meter, and the height of the rivets is half the thickness of the insulation layer 5. The material of the insulation layer 5 can be an amorphous refractory material, such as a corundum mullite refractory material, a silicon carbide high-aluminum mullite refractory material, a corundum mullite refractory material or a silicon carbide refractory material; it can also be a shaped refractory material, for example, a silicon brick or a high-aluminum brick.

[0027] Combination Figure 2 As shown, the protective member 3 is a cylinder with a placement groove 31 on the outer wall, and the side of the protective member 3 with the placement groove 31 is fixedly connected to the insulation layer 5, and the placement groove 31 is used to accommodate the heating component 2; the depth of the placement groove 31 can be 5-10mm. In some specific embodiments, the heating component 2 includes a heating wire arranged around the inner wall of the furnace tube, and the heating wire is placed in the placement groove 31. The protective member 3 can be made of ceramic, silicon nitride ceramic shell, aluminum oxide ceramic, zirconium oxide ceramic, silicon carbide ceramic or glass fiber.

[0028] It is understandable that in order to allow the furnace tube body 1 to be heated evenly, the heating components 2 can be set to multiple and can be evenly distributed along the length direction of the furnace tube body 1, and the number of placement slots 31 is the same as the number of heating components 2. Each heating component 2 is electrically connected to the external power supply through the connecting component 4, and multiple heating components 2 are arranged in parallel. The heating component 2 is installed in the placement slot 31. If damaged, it can be pulled out of the placement slot 31 for replacement. The maintenance process of the heating component 2 is convenient and fast. Each heating component 2 is in parallel, and the control of different temperature zones of the entire furnace body can be achieved by individually controlling each heating component 2. Even if some of the heating components 2 are damaged, it will not have a serious impact on the heating process. The working process of the rotary kiln is stable and reliable.

[0029] It should be noted that the protective member 3 can be a complete cylinder of the same length as the furnace tube body 1 to reduce the splicing seam, or it can be divided into multiple cylinders along its length direction to meet the needs of a large-sized furnace tube body 1. In this case, multiple cylinders are spliced ​​along their length direction to reduce the processing difficulty of the protective member 3.

[0030] Combination Figure 1 and Figure 3As shown, the connection assembly 4 includes a first collector 41 and a second collector 42. The first collector 41 includes a first conductive ring 411, a second conductive ring 412, a metal cylinder 413 and a brush 414. The first conductive ring 411 is sleeved on the outer wall of the furnace tube body 1 and is relatively rotatably connected to the furnace tube body 1 through a bearing. The first conductive ring 411 can also be fixedly connected to the support. The metal cylinder 413 is sleeved on the outer wall of the furnace tube body 1, and one end of the metal cylinder 413 is integrally connected to the first conductive ring 411, and the other end is rotatably connected to the second conductive ring 412 through a bearing. The second conductive ring 412 is sleeved on the outer wall of the furnace tube body 1 and is fixedly connected to the furnace tube body 1; one end of the brush 414 is fixedly connected to the first conductive ring 411, and the other end is abutted against the second conductive ring 412. Both the first conductive ring 411 and the second conductive ring 412 can be provided with a plurality of conductive terminals. The conductive terminals on the first conductive ring 411 are connected to the wires of the municipal circuit and are electrically conductive.

[0031] Combination Figure 1 and Figure 4 As shown, a plurality of second current collectors 42 may be arranged at intervals along the length direction of the furnace tube body 1. For example, when the protective member 3 is arranged as a plurality of cylinders spliced ​​along the length direction thereof, the number of the second current collectors 42 may be consistent with the number of the protective members 3. The second current collector 42 comprises an insulating plate 421 and a conductive plate 422. The insulating plate 421 is sleeved on the outer wall of the furnace tube body 1 and is fixedly connected to the furnace tube body 1. The insulating plate 421 is made of insulating material, and the conductive plate 422 is integrally connected to the side of the insulating plate 421 away from the furnace tube body 1. A plurality of conductive terminals are arranged circumferentially on the outer wall of the conductive plate 422. The conductive terminals on the conductive plate 422 are used to be electrically connected to the wires of the heating assembly 2. In other words, the conductive terminals on the conductive plate 422 are connected to and electrically conductive with the wires of the circuit where the heating assembly 2 is located, and the wires of the circuit where the heating assembly 2 is located are connected to and electrically conductive with the conductive terminals on the second conductive ring 412 after being connected to the conductive plate 422. It can be understood that the first conductive ring 411, the second conductive ring 412, the metal cylinder 413, the conductive plate 422, and the conductive terminal are all made of conductive metal materials, and the brush 414 is usually made of carbon or other conductive materials, which has the characteristics of wear resistance and good conductivity. When the second conductive ring 412 rotates with the furnace tube body 1, the brush 414 can continuously and stably contact the second conductive ring 412, thereby transmitting power or data signals, so that the wires of the external power supply are connected to the wires of the heating component 2. The first collector 41 is connected to the city power supply, which plays the role of supplying power to the entire rotary kiln equipment.

[0032] When the rotary kiln is working, the second conductive ring 412 rotates synchronously with the furnace tube body 1, the first conductive ring 411 remains relatively still, the wires of the external power supply are connected to the first conductive ring 411, and the wires of the heating component 2 pass through the insulation layer 5 and the peripheral wall of the furnace tube body 1 in sequence, and are connected to the conductive plate 422 and the second conductive ring 412 in sequence. The heating component 2 is electrically connected to the mains power through the cooperation of the first collector 41 and the second collector 42, and the wires will not be entangled due to the rotation of the furnace tube body 1. In other words, the arrangement of the first collector 41 and the second collector 42 allows the heating component 2 to function efficiently.

[0033] In some embodiments, due to the existence of processing errors, there are likely to be joints between the heating component 2 and the insulation layer 5, and between two adjacent heating components 2. Refractory ceramic cement can be used to bond the joints. In this case, the refractory ceramic cement can not only compensate for the errors, but also effectively ensure the connection strength between them after solidification.

[0034] like Figure 5 As shown, a stirring member 6 is connected to the outer wall of the protective member 3, and the material of the stirring member 6 can be the same as that of the protective member 3. The stirring member 6 includes a connecting plate 61, a reinforcing plate 62 and a lifting plate 63. The connecting plate 61 is attached to the outer wall of the protective member 3 and is fixedly connected to the protective member 3. As a specific example, the connecting plate 61 is bonded to the outer surface of the protective member 3 by refractory ceramic cement. One side of the reinforcing plate 62 is integrally connected to the connecting plate 61, and the other end is fixedly connected to the lifting plate 63 by a ceramic screw, which is convenient for replacing and maintaining the lifting plate 63. The lifting plate 63 is arranged in parallel with the reinforcing plate 62, and the end of the lifting plate 63 coincides with the end of the reinforcing plate 62.

[0035] It should be noted that in actual production, due to the different particle sizes and fluidity of the calcined materials, the lifting plate 63 can be processed into a spiral lifting plate 63, a flat lifting plate 63 or a combination of the two according to actual needs, which will not be described in detail here.

[0036] In normal operation, the first collector 41 and the second collector 42 provide power to the heating assembly 2, and the insulation layer 5 prevents the heat generated by the heating assembly 2 from diffusing outward, so that the temperature of the furnace tube body 1 is maintained below 40°C; the heat generated by the heating assembly 2 is transferred to the furnace material through the protective member 3, which not only plays a heating role, but also plays a role in isolating the material from the heating assembly 2. It can be seen that the rotary kiln provided by the present invention can prevent the furnace tube body 1 from contacting a high temperature environment, thereby greatly reducing the requirements of the furnace tube body 1 for materials; and the outermost layer of the furnace tube body 1 does not contact the heated material, thereby avoiding damage to the furnace tube body 1 and reducing the contamination of the material by metal components such as Fe, Ni, Cr, Mn, and Mo in the furnace tube body 1.

[0037] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A rotary kiln, characterized in that: It includes a furnace tube body, a heating component, a protective member and a connecting component. The heating component is distributed on the inner circumferential wall of the furnace tube body. The heating component is electrically connected to the furnace tube body through the connecting component. The protective member surrounds the outer circumference of the heating component and is fixedly connected to the inner wall of the furnace tube body.

2. A rotary kiln according to claim 1, characterized in that: The protective member is a cylinder with a placement groove, and the side of the protective member with the placement groove is connected to the furnace tube body; the placement groove is used to accommodate the heating component.

3. A rotary kiln according to claim 1, characterized in that: The heating component comprises a plurality of heating wires arranged around the inner wall of the furnace tube, and each of the heating wires is electrically connected to an external power source through the connecting component.

4. A rotary kiln according to claim 3, characterized in that: The connecting assembly comprises a first current collector and a second current collector, wherein the first current collector comprises a first conductive ring, a second conductive ring, a metal cylinder and a brush, wherein the first conductive ring is sleeved on the outer wall of the furnace tube body and is relatively rotatably connected to the furnace tube body, the metal cylinder is sleeved on the outer wall of the furnace tube body, one end of the metal cylinder is fixedly connected to the first conductive ring, and the other end is rotatably connected to the second conductive ring, the second conductive ring is sleeved on the outer wall of the furnace tube body and is fixedly connected to the furnace tube body; one end of the brush is connected to the first conductive ring, and the other end is in contact with the second conductive ring; the first conductive ring and the second conductive ring are both provided with conductive terminals; The second current collector includes an insulating plate and a conductive plate. The insulating plate is sleeved on the outer wall of the furnace tube body and fixedly connected to the furnace tube body. The conductive plate is fixedly connected to a side of the insulating plate away from the furnace tube body. The outer wall of the conductive plate is provided with a conductive terminal.

5. A rotary kiln according to claim 4, characterized in that: The heating components are arranged in parallel.

6. A rotary kiln according to claim 1, characterized in that: The protective member is made of ceramic, silicon nitride ceramic shell, aluminum oxide ceramic, zirconium oxide ceramic, silicon carbide ceramic or glass fiber.

7. A rotary kiln according to claim 1, characterized in that: The inner wall of the furnace tube body is connected with a heat-insulating layer, and the heating component is located on a side of the heat-insulating layer away from the inner wall of the furnace tube body.

8. A rotary kiln according to claim 7, characterized in that: The material of the thermal insulation layer is a high-aluminum mullite refractory material, a corundum mullite refractory material and / or a silicon carbide refractory material.

9. A rotary kiln according to any one of claims 1 to 8, characterized in that: The outer wall of the protection member is connected with a stirring member.

10. A rotary kiln according to claim 9, characterized in that: The stirring member includes a connecting plate, a reinforcing plate and a lifting plate. The connecting plate is fitted with the outer wall of the protective member and is fixedly connected to the protective member. One side of the reinforcing plate is fixedly connected to the connecting plate, and the other end is fixedly connected to the lifting plate. The end of the lifting plate coincides with the end of the reinforcing plate.

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