Double-barrel roasting kiln body and double-barrel roasting rotary kiln

Abstract

The utility model provides a double-barrel roasting kiln body and a double-barrel roasting rotary kiln, and belongs to the field of neodymium iron boron waste roasting oxidation. The double-barrel roasting kiln body comprises a rotating outer barrel and a rotating inner barrel, and the moving direction of materials in an inner cavity of the inner barrel is opposite to the moving direction of materials in an inner cavity of the outer barrel. At least two first gear rings are arranged on the outer wall of the inner cylinder, and arc-shaped tooth support groups in one-to-one correspondence with the first gear rings are arranged on the inner wall of the outer cylinder, so that the rotating outer cylinder drives the inner cylinder to rotate through the first gear rings and the arc-shaped tooth support groups which are meshed with each other; the tail end, in the material moving direction, of the outer barrel is fixedly connected with a feeder, and the functional end of the feeder extends into an inner cavity of the inner barrel. According to the double-barrel roasting rotary kiln, the double-barrel roasting kiln body is adopted, secondary roasting can be conducted on the inner barrel through combustion waste heat of the outer barrel, and the heat energy utilization rate is increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of roasting and oxidation of NdFeB waste materials, and particularly relates to a double-drum roasting kiln body and a double-drum roasting rotary kiln using the double-drum roasting kiln body. Background Art

[0002] Waste materials such as scraps, sludge, abrasives, and scrap generated during the smelting, casting, sintering, cutting, and polishing of rare earth materials are collectively referred to as NdFeB scrap. Because it contains rare earth elements, it has a high recycling value. Recycling NdFeB scrap not only rationally utilizes resources but also reduces environmental pollution. In the treatment process for NdFeB scrap, which primarily contains rare earth metals, iron, organic oil, and other organic impurities, it is fed into an internal combustion rotary kiln. Leveraging the oil content in the sludge and abrasives and the flammability of the rare earth metals, the organic oil and organic impurities are removed through combustion. The rare earth metals and iron are then oxidized while maintaining a constant temperature, reducing hydrochloric acid consumption in the subsequent acid leaching process.

[0003] Currently, NdFeB scrap is typically recycled using a single-tube roasting rotary kiln. The high-temperature roasting period for organic matter in this kiln is relatively short, resulting in insufficient oxidation of the iron metal. This drawback is addressed by adding high-organic waste or providing additional fuel. However, this can easily lead to excessively high roasting temperatures, causing the metallic iron to oxidize into a crystalline Fe3O4 structure, hindering the extraction of rare earth elements in the subsequent acid leaching process. To further increase the oxidation rate of the metallic iron in the roasted scrap (i.e., the proportion of Fe2O3 in the total iron), the powder produced by the single-tube roasting rotary kiln must be further subjected to high-temperature oxidation in a roasting rotary kiln fueled by coal or gas. However, this secondary roasting significantly increases fuel consumption and equipment investment.

[0004] Therefore, how to solve the disadvantage of the current single-drum roasting rotary kiln that the metal iron oxidation rate of NdFeB scrap needs to be increased and then roasted again is a problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a double-drum roasting kiln body and a double-drum roasting rotary kiln. By adopting a double-drum roasting kiln body, the waste heat from the combustion of the outer drum is used to perform secondary roasting on the inner drum, which can improve the utilization rate of thermal energy and effectively solve the disadvantage that NdFeB waste needs to be roasted twice.

[0006] On the one hand, the application provides a double-drum roasting kiln body, comprising:

[0007] an outer cylinder, which is rotatably arranged;

[0008] An inner cylinder, one end of which extends into the inner cavity of the outer cylinder, and the direction of movement of the material in the inner cavity of the inner cylinder is opposite to the direction of movement of the material in the inner cavity of the outer cylinder;

[0009] Among them, the outer wall of the inner cylinder is provided with at least two first gear rings, and the inner wall of the outer cylinder is provided with an arc-shaped tooth support group arranged in a one-to-one correspondence with the first gear rings, so that the rotating outer cylinder drives the inner cylinder to rotate through the meshing first gear rings and the arc-shaped tooth support group; the outer cylinder is fixedly connected to a loader at the end thereof in the material moving direction, and the functional end of the loader is extended into the inner cavity of the inner cylinder.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: by adopting a double-layer structure of a roasting kiln body with an inner cylinder and an outer cylinder, the outer wall of the inner cylinder and the inner wall of the outer cylinder are provided with a meshing first gear ring and an arc-shaped gear support, so that the rotating outer cylinder drives the inner cylinder to rotate synchronously; this structural design realizes the material in the roasting kiln body to be preheated by the outer cylinder to achieve two high-temperature roastings without the need for additional power and facilities; secondly, the material slowly creeps in the outer cylinder and the inner cylinder, and the material will turn over, so that the high-temperature material is fully oxidized by the air, thereby improving the oxidation efficiency.

[0011] Preferably, the loader includes a base plate fixed on the outer cylinder, a conical platform provided on the base plate and a plurality of curved panels arranged around the conical surface of the conical platform, and the plurality of curved panels are all bent in the same direction; one end of the conical platform extends into the inner cavity of the inner cylinder, and the width of the curved panel is smaller than the width of the conical surface of the conical platform.

[0012] Preferably, one end of the curved plate away from the conical platform abuts against the inner wall of the inner cylinder.

[0013] Preferably, each of the arc-shaped tooth support groups includes a plurality of arc-shaped teeth with equal tooth heights and spaced apart.

[0014] Preferably, the tooth heights of the arc-shaped teeth at different positions decrease sequentially along the moving direction of the material in the inner barrel.

[0015] Preferably, the outer wall of the outer cylinder is sleeved with a second gear ring and a rolling ring, the second gear ring is engaged with an external power gear, and the rolling ring is placed on an external supporting wheel.

[0016] Preferably, the outer tube and the inner tube are both made of heat-resistant pipes lined with refractory bricks.

[0017] Preferably, a plurality of lifting plates are provided on the inner walls of the outer cylinder and the inner cylinder.

[0018] On the other hand, the application provides a double-drum roasting rotary kiln, including a feeding device, a power device and a collector, and also includes the above-mentioned double-drum roasting kiln body, the feeding device is connected to the feeding end of the outer cylinder, the power device drives the outer cylinder to rotate, and the collector is connected to the discharge end of the inner cylinder and is clearance-matched.

[0019] Compared to existing technologies, the present invention offers the following advantages: The double-drum roasting rotary kiln utilizes the aforementioned double-drum roasting kiln body, enabling two high-temperature roasting cycles within the double-drum kiln body. Furthermore, the high-temperature material is fully oxidized by air, resulting in high oxidation efficiency. Furthermore, because the outer drum kiln tail is sealed, dust can only flow into the inner drum and be discharged through the exhaust port of the collector, preventing dust leakage from the tail of conventional roasting kilns. This reduces dust generation and improves the on-site environment.

[0020] Preferably, the collector is provided with an air exhaust port, and the air exhaust port is connected to a bag dust collector. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 A schematic plan view of a double-drum roasting rotary kiln provided in Example 1 of the present utility model;

[0023] Figure 2 A schematic cross-sectional view of a double-barrel roasting kiln provided in Example 1 of the present utility model;

[0024] Figure 3 A perspective view of a loader provided in Example 1 of the present utility model;

[0025] Figure 4 Schematic diagram of the engagement between the first gear ring and the arc-shaped gear support assembly provided in Example 1 of the present utility model;

[0026] Figure 5 A three-dimensional diagram of the arc-shaped teeth provided in Example 1 of the present utility model;

[0027] Figure 6 Schematic diagram of the engagement between the first gear ring and the arc-shaped gear support group provided in Example 2 of the present utility model.

[0028] Description of reference numerals:

[0029] 10-double-drum roasting kiln body, 11-outer drum, 111-second gear ring, 112-rolling ring, 113-arc-shaped teeth, 114-rib, 115-lifting plate, 12-inner drum, 121-first gear ring, 13-loader, 131-bottom plate, 132-conical platform, 133-curved plate;

[0030] 20-feeding device, 21-hopper;

[0031] 30-power device, 31-motor, 32-power gear;

[0032] 40-collector, 41-discharge port, 42-exhaust port, 43-bag dust collector, 44-exhaust fan. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0034] In the description of the embodiments of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium; internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment provides a double-drum roasting rotary kiln, comprising a feeding device 20, a power device 30, a collector 40 and a double-drum roasting kiln body 10. The feeding device 20 is connected to the feeding end of the double-drum roasting kiln body 10, the collector 40 is connected to the discharging end of the double-drum roasting kiln body 10, and a gap is left between the collector 40 and the double-drum roasting kiln body 10. In this embodiment, the feeding device 20 can use a conveyor belt device to automatically convey the NdFeB waste into the double-drum roasting kiln body 10, wherein a hopper 21 is provided above the conveyor belt device, and the NdFeB waste is automatically dropped into the conveyor belt device through the hopper 21 by an external feeding device.

[0038] Furthermore, the collector 40 is provided with a discharge port 41 and an exhaust port 42. The discharge port 41 is connected to an external storage device for collecting the calcined NdFeB scrap. The exhaust port 42 is connected to a bag filter 43, which is equipped with an exhaust fan 44. The exhaust fan 44 allows the kiln tail dust after calcination to be stored in the bag filter 43, preventing the leakage of the kiln tail dust and preventing it from affecting the on-site environment.

[0039] Furthermore, the outer wall of the twin-drum kiln body 10 is sheathed with a second gear ring 111 and a rolling ring 112. In this embodiment, the power unit 30 comprises a motor 31 and a power gear 32 disposed at the output end of the motor 31. The second gear ring 111 meshes with the power gear 32, and the rolling ring 112 is mounted on an external support roller. In practice, the motor drives the power gear to rotate, driving the entire twin-drum kiln body. The rolling ring rotates synchronously on the support roller, supporting the smooth rotation of the twin-drum kiln body.

[0040] like Figure 2 As shown, the double-drum roasting kiln body 10 includes an outer cylinder 11 and an inner cylinder 12 which are made of heat-resistant tubes lined with refractory bricks and are nested with each other, wherein the outer cylinder 11 is located at the end opening in the direction of material movement, and a loader 13 is fixedly installed on the opening. In this embodiment, one end of the inner cylinder 12 extends into the inner cavity of the outer cylinder 11, but does not touch the loader 13 installed at the end of the outer cylinder 11. In specific practice, the loader is used to transport the material in the inner cavity of the outer cylinder to the inner cavity of the inner cylinder. It should be noted that the second gear ring and the rolling ring of this embodiment are both sleeved on the outer wall of the outer cylinder, and the height setting of the second gear ring and the rolling ring makes the feed end of the outer cylinder high and the end low, with the purpose of prompting the material in the outer cylinder to move from the feed end to its end.

[0041] like Figure 3 As shown, the feeder 13 includes a bottom plate 131, a conical platform 132 and a plurality of curved plates 133. Figure 2As shown, the bottom plate 131 is fixedly mounted at the open end of the outer cylinder 11 and sealed. The conical platform 132 is located in the middle of the bottom plate 131, and a plurality of curved panels 133 are evenly distributed around the conical surface of the conical platform 132. Preferably, the curved panels 133 are all curved in the same direction, their width is smaller than the width of the conical surface of the conical platform 132, and the end of the curved panel 133 facing away from the conical platform 132 abuts the inner wall of the inner cylinder 12. In this embodiment, one end of the conical platform 132 extends into the inner cavity of the inner cylinder 12, leaving a gap between the two for material transfer. In practice, material at the end of the outer cylinder is lifted and placed onto the curved panel by the rotating curved panel. When positioned at a certain position, the material on the curved panel slides along the conical surface of the conical platform and enters the inner cavity of the inner cylinder through the gap, thereby transferring material from the outer cylinder to the inner cylinder.

[0042] like Figure 2 and Figure 4 As shown, two first gear rings 121 are provided on the outer wall of the inner cylinder 12, and an arcuate tooth support group corresponding to the first gear rings 121 is provided on the inner wall of the outer cylinder 11. Through the engagement of the first gear rings 121 with the arcuate tooth support group, when the outer cylinder rotates, the combined first gear rings 121 and the arcuate tooth support group can drive the inner cylinder 12 to rotate synchronously. This structural design allows the inner cylinder 12 to rotate without additional power.

[0043] like Figure 5 As shown, the arc-shaped tooth support group includes a plurality of arc-shaped teeth 113 with equal tooth height. Wherein, ribs 114 are provided on both sides of the arc-shaped teeth 113. Figure 4 As shown, the arrangement of the baffle 114 allows the first gear ring 121 to rotate only within the rotational trajectory formed by the arcuate teeth 113, thereby preventing the rotating inner cylinder 12 from shifting or falling off. Preferably, the different arcuate teeth 113 within the same arcuate tooth support group are spaced apart to prevent material within the inner cylinder 12 from being blocked by the arcuate teeth 113 and hindering its movement within the inner cylinder 12.

[0044] like Figure 2As shown, in order to achieve the direction of material movement in the inner cavity of the inner cylinder 12 opposite to the direction of material movement in the inner cavity of the outer cylinder 11, the purpose is to save the overall space occupancy of the double-cylinder roasting rotary kiln and utilize the residual heat from the combustion of the outer cylinder 11 to perform a secondary roasting of the material in the inner cylinder 12, thereby solving the problem of fuel consumption required for secondary roasting. Based on the movement of the material in the outer cylinder 11 from its feed end to its end in this embodiment, in order to achieve the direction of material movement in the inner cavity of the inner cylinder 12 opposite to the direction of material movement in the outer cylinder 11, the tooth height of the arc-shaped teeth 113 at different positions is arranged to decrease in sequence along the direction of material movement in the inner cylinder 12.

[0045] The working mechanism of this embodiment is: start the exhaust fan and the power device, pour the NdFeB waste into the hopper, and send it into the inner cavity of the outer cylinder through the feeding device. The ignited NdFeB waste is fully in contact with the air under the rotation of the inclined outer cylinder and burns; it slowly crawls to the loader at the end of the kiln, and the curved plate of the loader lifts the once roasted NdFeB waste to the top of the loader as the outer cylinder rotates, and then slides into the inner cavity of the inner cylinder along the conical surface of the conical table due to gravity; the once roasted NdFeB waste slowly crawls to the combustion section of the outer cylinder under the rotation of the inner cylinder that is tilted in the opposite direction to the outer cylinder, and is fully in contact with the air under the action of the residual heat and high temperature for secondary roasting. The NdFeB waste undergoes secondary roasting; after sufficient combustion, it crawls to the kiln head of the inner cylinder and enters the collector, and enters the storage device through the discharge port of the collector. Since the kiln tail of the outer tube is sealed, the roasting dust can only flow to the inner tube and be discharged from the exhaust port of the collector, avoiding the leakage of dust at the tail of the conventional roasting kiln, generating less dust and improving the on-site environment.

[0046] Example 2

[0047] like Figure 6 As shown, this embodiment differs from Example 1 in that a plurality of lifting plates 115 are provided on the inner walls of both the outer cylinder 11 and the inner cylinder 12. The lifting plates 115 are positioned toward the center of the cylinder and between adjacent arc-shaped teeth 113. By providing the lifting plates on the inner walls of the outer cylinder and the inner cylinder, this embodiment can lift the NdFeB waste within the cylinders, allowing the NdFeB waste to fully contact air for combustion, thereby improving oxidation efficiency.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-drum roasting kiln; characterized in that, include: an outer cylinder, which is rotatably arranged; An inner cylinder, one end of which extends into the inner cavity of the outer cylinder, and the direction of movement of the material in the inner cavity of the inner cylinder is opposite to the direction of movement of the material in the inner cavity of the outer cylinder; Among them, the outer wall of the inner cylinder is provided with at least two first gear rings, and the inner wall of the outer cylinder is provided with an arc-shaped tooth support group arranged in a one-to-one correspondence with the first gear rings, so that the rotating outer cylinder drives the inner cylinder to rotate through the meshing first gear rings and the arc-shaped tooth support group; the outer cylinder is fixedly connected to a loader at the end thereof in the material moving direction, and the functional end of the loader is extended into the inner cavity of the inner cylinder.

2. The double-barrel roasting kiln according to claim 1, characterized in that: The loader includes a base plate fixed on the outer cylinder, a conical platform provided on the base plate, and a plurality of curved panels arranged around the conical surface of the conical platform, wherein the plurality of curved panels are all bent in the same direction; one end of the conical platform extends into the inner cavity of the inner cylinder, and the width of the curved panel is smaller than the width of the conical surface of the conical platform.

3. The double-drum roasting kiln according to claim 2, characterized in that: One end of the curved plate away from the conical platform abuts against the inner wall of the inner cylinder.

4. The double-drum roasting kiln according to claim 1, characterized in that: The arc-shaped tooth support groups each include a plurality of arc-shaped teeth with equal tooth heights and spaced apart.

5. The double-drum roasting kiln according to claim 4, characterized in that: The tooth heights of the arc-shaped teeth at different positions decrease in sequence along the moving direction of the material in the inner barrel.

6. The double-drum roasting kiln according to claim 1, characterized in that: The outer wall of the outer cylinder is sleeved with a second gear ring and a rolling ring. The second gear ring is engaged with an external power gear, and the rolling ring is placed on an external supporting wheel.

7. The double-drum roasting kiln according to claim 1, characterized in that: The outer tube and the inner tube are both made of heat-resistant pipes lined with refractory bricks.

8. The double-drum roasting kiln according to any one of claims 1 to 7, characterized in that: A plurality of material lifting plates are provided on the inner walls of the outer cylinder and the inner cylinder.

9. A double-drum roasting rotary kiln, comprising a feeding device, a power device and a collecting device, characterized in that: It also includes a double-drum roasting kiln body as described in any one of claims 1 to 8, wherein the feeding device is connected to the feeding end of the outer drum, the power device drives the outer drum to rotate, and the collector is connected to the discharge end of the inner drum and is clearance-fitted.

10. The double-drum roasting rotary kiln according to claim 9, characterized in that: The collector is provided with an air exhaust port, which is connected to the bag dust collector.

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