A rotary kiln main kiln for processing neodymium iron boron waste

Abstract

The application provides a rotary kiln main kiln for treating neodymium iron boron waste, which comprises a kiln head and a kiln tail smoke chamber, an inclined rotary kiln pipe is arranged between the kiln head and the kiln tail smoke chamber, a driving mechanism is arranged below the kiln pipe to drive the kiln pipe in the circumferential direction, a fuel bin and a blower are connected to the kiln head, a feeding hopper extending into the kiln pipe is arranged on the top of one end of the kiln tail smoke chamber close to the kiln pipe, an exhaust pipe is arranged on one side of the feeding hopper and connected to the kiln tail smoke chamber, a filter plate composed of rotary connected filter plates is arranged at the connection between the exhaust pipe and the kiln tail smoke chamber, the filter plates are driven by steam to flip and collide with each other through a waste heat driving mechanism in the kiln tail smoke chamber, the self-cleaning of the filter plates is realized by driving with the waste heat of the tail gas, the secondary recovery of heat energy is realized, waste is avoided, the self-cleaning of the filter plates is realized without manual operation, and the application has a good development prospect.

Description

Technical Field

[0001] This invention relates to the field of neodymium iron boron (NdFeB) recycling, specifically to a rotary kiln main kiln for processing NdFeB waste. Background Technology

[0002] During the production of sintered NdFeB alloy permanent magnets, waste materials generated during cutting, grinding, and oxidation processes will produce waste.

[0003] 30%-40% of the waste material has an elemental composition basically the same as the alloy material, with a rare earth element content far exceeding that in rare earth ores. Recycling the rare earth elements from this processing waste has extremely high economic value and social and environmental benefits. Currently, wet recycling is commonly used for NdFeB alloy processing waste.

[0004] In the wet recycling process, the sintering of waste materials is usually carried out using a rotary kiln. During the firing process of the rotary kiln, a large amount of smoke and dust is generated and blown out by the kiln head blower. Therefore, a dust collection chamber and filter screen are often set up at the kiln tail to filter the exhaust gas. However, as the filtration time of the filter screen increases, dirt will gradually accumulate on the surface of the filter screen, affecting the maximum airflow of the filter screen and affecting the exhaust gas discharge and the sintering of waste materials. The dust removal of the filter screen requires the use of external devices, which is both time-consuming and labor-intensive, and also increases the operating cost of the rotary kiln.

[0005] Therefore, a rotary kiln main kiln with a self-cleaning filter function is needed for the recycling and treatment of NdFeB waste. Summary of the Invention

[0006] The purpose of this invention is to provide a rotary kiln main kiln for processing NdFeB waste.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A rotary kiln main kiln for processing NdFeB waste includes a kiln head and a kiln tail smoke chamber. A kiln tube is rotatably installed between the kiln head and the kiln tail smoke chamber. A drive mechanism is attached to the bottom of the kiln tube to drive the kiln tube circumferentially. A fuel bin and a blower are connected to the kiln head. A feed hopper extending into the kiln tube is installed at the top of the kiln tail smoke chamber near the kiln tube. An exhaust pipe is installed on one side of the feed hopper and connected to the kiln tail smoke chamber. A filter plate composed of rotatably connected filter plates is installed at the connection between the exhaust pipe and the kiln tail smoke chamber. The filter plates are self-cleaned by being driven by the waste heat in the kiln tail smoke chamber to rotate and collide with each other.

[0009] As a further aspect of the present invention: the filter plate includes a frame and a filter plate. The frame is a rectangular frame structure and is fixed to the bottom of the flue pipe. Filter plates are rotatably arranged at intervals inside the frame. A steam channel connected to a waste heat drive mechanism is provided on one side of the frame. One end of the filter plate extends into the steam channel and is connected to a drive impeller. The rotation of the filter plate is driven by the steam flow. An elastic element is provided at the connection between the filter plate and the frame to limit the initial angle of the filter plate.

[0010] As a further aspect of the present invention: the filter plate includes an air-impact plate and impact teeth. The air-impact plate is a sheet-like plate structure. Two sets of impact teeth are provided on the surface of the air-impact plate. The impact teeth are symmetrically arranged along the central axis of the air-impact plate, and the impact teeth of adjacent air-impact plates are staggered.

[0011] As a further embodiment of the present invention: the waste heat driving mechanism includes a preheating plate, an evaporation chamber and a pressure cylinder. The preheating plate is fixed on both sides of the kiln tail smoke chamber. The evaporation chamber is fixed on the side of the kiln tail smoke chamber opposite to the kiln tube. Both the evaporation chamber and the preheating plate are hollow structures and are interconnected. The preheating plate and the evaporation chamber are respectively provided with a water inlet and a water outlet. The top of the evaporation chamber is provided with a pressure cylinder that is in air communication with the filter plate. The pressure cylinder is a hydraulic cylinder structure with initial pressure, and the opening and closing of the air passage is controlled according to the pressure.

[0012] As a further aspect of the present invention: the evaporation chamber is an arc-shaped plate, and the corresponding parts of the preheating plates on both sides are arc-shaped edges.

[0013] As a further embodiment of the present invention: the preheating plate includes a U-shaped heat absorption channel and an isolation channel. An isolation channel is provided along the inner edge of the preheating plate that is joined to the evaporation chamber. The connection between the preheating plate and the evaporation chamber is located in the isolation channel. The remaining positions are U-shaped heat absorption channels arranged in an S-shape, with both ends connected to the water inlet and one end of the isolation channel, respectively.

[0014] As a further aspect of the present invention: the accumulator cylinder includes a connecting cylinder and an accumulator cylinder connected by a connecting seat. A first slider and a second slider are respectively provided in the connecting cylinder and the accumulator cylinder. Oil is injected between the first slider and the second slider for hydraulic transmission. An air guide pipe connected to the filter plate is provided on the side of the connecting cylinder. A pressure spring is provided between the second slider and the accumulator cylinder structure to indirectly act on the first slider, so that the first slider always maintains a downward movement tendency to block the air guide pipe opening.

[0015] As a further aspect of the present invention: an adjusting bolt is threadedly connected at the connection point between the connecting cylinder and the accumulator cylinder on the connecting seat to control the flow rate of the connecting channel.

[0016] As a further aspect of the present invention: the first slider includes a switching body and a delay slider. The switching body is slidably disposed in the connecting cylinder to control the opening and closing of the gas guide pipe. A strip-shaped groove distributed along the sliding direction of the switching body is recessed on one side of the switching body corresponding to the gas guide pipe. The bottom of the groove has a channel communicating with the evaporation chamber. A delay slider with a length shorter than the groove is slidably disposed in the groove.

[0017] As a further aspect of the present invention: a pull-out ash collection tray is provided on one side of the kiln tail smoke chamber below the filter plate.

[0018] Beneficial effects

[0019] 1. The filter plate of the present invention includes a frame and filter plates. The frame is a rectangular frame structure and is fixed to the bottom of the flue pipe. Filter plates are rotatably arranged at intervals inside the frame. A steam channel connected to a waste heat drive mechanism is provided on one side of the frame. One end of the filter plate extends into the steam channel and is connected to a drive impeller. The steam generated by the waste heat drive mechanism drives the rotation of the filter plate. An elastic element is provided at the connection between the filter plate and the frame to limit the initial angle of the filter plate. By rotating the filter plate under the drive of steam, the filter plate collides with adjacent filter plates, shaking off the dust adhering to the gaps and the surface, thus achieving self-cleaning of the filter plate.

[0020] 2. The waste heat drive mechanism of the present invention is equipped with a pressure cylinder that is in air communication with the filter plate. The pressure cylinder is a hydraulic cylinder structure with initial pressure. The opening and closing of the air passage is controlled according to the pressure. The pressure cylinder continuously increases the pressure of the steam in the evaporation chamber, avoiding insufficient driving force caused by continuous small flow of steam. It also intervals the self-cleaning time of the filter plate, reduces the number of self-cleaning times of the filter screen, and prevents excessively frequent self-cleaning from affecting the filtration effect.

[0021] 3. In this invention, an adjusting bolt is threadedly connected to the connection between the connecting cylinder and the accumulator cylinder on the connecting seat to control the flow rate of the connection channel. By setting the adjusting bolt, the oil flow rate can be controlled by controlling the screw-in depth of the adjusting bolt, that is, the reset speed of the first slider can be controlled. By slowing down the reset speed of the first slider, the gas connection time between the evaporation chamber and the filter plate is increased, ensuring the complete release of steam, extending the trigger interval time, reducing the number of self-cleaning times of the filter screen, and preventing excessively frequent self-cleaning from affecting the filtration effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 This is a schematic diagram of the waste heat drive mechanism of the present invention.

[0024] Figure 3 This is a cross-sectional view of the preheating plate structure of the present invention.

[0025] Figure 4 This is a schematic diagram of the filter plate structure of the present invention.

[0026] Figure 5 This is a schematic diagram of the accumulation cylinder structure of the present invention.

[0027] Figure 6 This is a cross-sectional schematic diagram of the pressure cylinder structure of the present invention.

[0028] Figure 7 This is a cross-sectional schematic diagram of the first slider structure of the present invention.

[0029] Figure 1-7 In the middle: 1-Kiln head, 2-Kiln tail smoke chamber, 3-Kiln pipe, 4-Drive mechanism, 5-Fuel bin, 6-Blower, 7-Feed hopper, 8-Filter plate, 81-Plate frame, 82-Filter plate, 821-Air impact plate, 822-Impact tooth, 83-Drive impeller, 84-Elastic element, 9-Waste heat drive mechanism, 91-Preheating plate, 92-Evaporation chamber, 93-Accumulation cylinder, 931-Connecting cylinder, 932-First slider, 9321-Switch body, 9322-Delay slider, 933-Air guide pipe, 934-Accumulation cylinder, 935-Connecting seat, 936-Second slider, 937-Pressure spring, 938-Adjusting bolt, 10-Ash collection plate, 11-Exhaust pipe. Detailed Implementation

[0030] The following description, in conjunction with the accompanying drawings, will illustrate the present invention. Figures 1-7 The specific technical solutions of the present invention will be clearly and completely described.

[0031] Please see Figures 1-7 , Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the waste heat drive mechanism of the present invention; Figure 3 This is a cross-sectional view of the preheating plate structure of the present invention; Figure 4 This is a schematic diagram of the filter plate structure of the present invention; Figure 5 This is a schematic diagram of the accumulation cylinder structure of the present invention; Figure 6 This is a cross-sectional schematic diagram of the accumulation cylinder structure of the present invention; Figure 7 This is a cross-sectional schematic diagram of the first slider structure of the present invention.

[0032] This embodiment provides a rotary kiln main kiln for processing NdFeB waste, including a kiln head 1 and a kiln tail smoke chamber 2. A kiln tube 3 is inclined and rotatably arranged between the kiln head 1 and the kiln tail smoke chamber 2. A drive mechanism 4 is attached to the lower part of the kiln tube 3 to drive the kiln tube 3 circumferentially. A fuel bin 5 and a blower 6 are connected to the kiln head 1. A feed hopper 7 extending into the kiln tube is arranged at the top of one end of the kiln tail smoke chamber 2 near the kiln tube 3. An exhaust pipe 11 is arranged on one side of the feed hopper 7 and connected to the kiln tail smoke chamber 2. A filter plate 8 composed of rotatably connected filter plates 82 is arranged at the connection between the exhaust pipe 11 and the kiln tail smoke chamber 2. The filter plates 8 are self-cleaned by being driven by the waste heat drive mechanism 9 in the kiln tail smoke chamber 2 to rotate and collide with each other.

[0033] The filter plate 8 includes a frame 81 and a filter plate 82. The frame 81 is a rectangular frame structure and is fixed to the bottom of the flue pipe 11. The filter plates 82 are rotatably arranged at intervals inside the frame 81. A steam channel connected to the waste heat drive mechanism 9 is provided on one side of the frame 82. One end of the filter plate 82 extends into the steam channel and is connected to a drive impeller 83. The rotation of the filter plate 82 is driven by the steam flow. An elastic element 84 is provided at the connection between the filter plate 82 and the frame 81 to limit the initial angle of the filter plate 82.

[0034] By rotating the filter plate 82 and flipping it under steam drive, it collides with the adjacent filter plate 82, shaking off the dust adhering to the gaps and surface, thus achieving self-cleaning of the filter plate 8.

[0035] Specifically, the filter plate 82 includes an air-impact plate 821 and impact teeth 822. The air-impact plate 821 is a sheet-like plate structure. Two sets of impact teeth 822 are provided on the surface of the air-impact plate 821. The impact teeth 822 are symmetrically arranged along the central axis of the air-impact plate 821, and the impact teeth 822 of adjacent air-impact plates 821 are staggered.

[0036] By using the impact teeth 822, the gap between the filter plates 82 can be controlled and the filtration effect at the gap can be improved. The impact teeth 822 can also improve the collision effect. The misaligned setting of the impact teeth 822 allows the filter plates 82 to collide again when they are reset, thus improving the cleaning efficiency.

[0037] The waste heat drive mechanism 9 includes a preheating plate 91, an evaporation chamber 92, and a pressure cylinder 93. The preheating plate 91 is fixed on both sides of the kiln tail smoke chamber 2. The evaporation chamber 92 is fixed on the side of the kiln tail smoke chamber 2 opposite to the kiln pipe 3. Both the evaporation chamber 92 and the preheating plate 91 are hollow structures and are interconnected. The preheating plate 91 and the evaporation chamber 92 are respectively provided with a water inlet and a water outlet. The top of the evaporation chamber 92 is provided with a pressure cylinder 93 that is in air communication with the filter plate 8. The pressure cylinder 93 is a hydraulic cylinder structure with initial pressure, which controls the opening and closing of the air passage according to the pressure.

[0038] The pressure and content of steam in the evaporation chamber 92 are continuously adjusted by the pressure cylinder 93 to avoid insufficient driving force caused by continuous small flow of steam. It also intervals the self-cleaning time of the filter plate 8, reducing the number of self-cleaning times of the filter screen 82 and preventing excessive self-cleaning from affecting the filtration effect.

[0039] Specifically, the evaporation chamber 92 is an arc-shaped plate, and the corresponding preheating plates 91 on both sides are arc-shaped edges. The arc-shaped structure guides the flue gas, regulates the flue gas flow direction, and improves the contact efficiency between the evaporation chamber 92 and the flue gas.

[0040] Specifically, the preheating plate 91 includes a U-shaped heat absorption channel and an isolation channel. An isolation channel 913 is provided along the inner edge of the preheating plate 91 where it meets the evaporation chamber 92. The connection between the preheating plate 91 and the evaporation chamber 92 is located in the isolation channel. The remaining positions are U-shaped heat absorption channels arranged in an S-shape, with both ends connected to the water inlet and one end of the isolation channel, respectively.

[0041] By setting up the heat insulation channel, direct contact between the newly introduced cold water and the evaporation chamber 92 is avoided, ensuring the water temperature inside the evaporation chamber 92. The setting of the U-shaped heat absorption channel increases the retention time of the water in the preheating plate 91, thereby improving the preheating effect.

[0042] Specifically, the accumulator cylinder 93 includes a connecting cylinder 931 and an accumulator cylinder 934 connected by a connecting seat 935. A first slider 932 and a second slider 936 are respectively provided in the connecting cylinder 931 and the accumulator cylinder 934. Oil is filled between the first slider 932 and the second slider 936 for hydraulic transmission. An air guide pipe 933 connected to the filter plate 8 is provided on the side of the connecting cylinder 935. A pressure spring 937 is provided between the second slider 936 and the accumulator cylinder 936 to indirectly act on the first slider 932, so that the first slider 932 always maintains a downward movement to block the opening of the air guide pipe 933.

[0043] Furthermore, an adjusting bolt 938 is threadedly connected to the connection point between the connecting cylinder 931 and the accumulator cylinder 934 on the connecting seat 935 to control the flow rate of the connection channel. By setting the adjusting bolt 938, the oil flow rate can be controlled by controlling the screw depth of the adjusting bolt 938, that is, the reset speed of the first slider 932 can be controlled. By slowing down the reset speed of the first slider 932, the gas connection time between the evaporation chamber 92 and the filter plate 8 is increased, ensuring the complete release of steam, extending the trigger interval time, reducing the number of self-cleaning times of the filter screen 82, and preventing excessively frequent self-cleaning from affecting the filtration effect.

[0044] Furthermore, the first slider 932 includes a switching body 9321 and a delay slider 9322. The switching body 9321 is slidably disposed in the connecting cylinder 931 to control the opening and closing of the air guide pipe 933. On the side of the switching body 9321 corresponding to the air guide pipe 933, there is a strip-shaped groove distributed along the sliding direction of the switching body 9321. The bottom of the groove has a channel communicating with the evaporation chamber 92. A delay slider 9322 with a length shorter than the groove is slidably disposed in the groove.

[0045] By setting the delay slider 9322, when the switch body 9321 falls under the hydraulic effect, the delay slider 9322 slides upward under the action of friction. The gas connection time is extended by the channel inside the switch body 9321, which ensures the complete release of steam, extends the trigger interval, reduces the number of self-cleaning times of the filter screen 82, and prevents excessively frequent self-cleaning from affecting the filtration effect.

[0046] Specifically, a pull-out ash collection tray 10 is provided on one side of the kiln tail smoke chamber 2 below the filter plate 8 to facilitate the collection of the cleaned dirt.

[0047] When implementing the technical solution described in this embodiment, the neodymium iron boron waste is introduced into the kiln tube 3 through the feed hopper 7. The kiln tube 3 rotates on its own driven by the drive mechanism 4, causing the waste inside to move towards the kiln head 1. The kiln head 1 sinters the waste inside the kiln tube 3 by burning fuel in the fuel chamber 5. At the same time, the blower 6 operates, driving the heat flow to preheat the waste at the rear end and to exhaust the flue gas.

[0048] The exhaust gas enters the kiln tail smoke chamber 2, which heats the water in the preheating plate 91 and the evaporation chamber 92. Part of the water evaporates, increasing the air pressure in the evaporation chamber 92. The remaining water is discharged through the outlet. After filtration, the exhaust gas is discharged from the exhaust pipe 11.

[0049] As the air pressure inside the evaporation chamber 92 gradually increases, overcoming the movement resistance brought by the pressure spring 937 inside the pressure cylinder 93, the first slider 932 rises until the air connection between the evaporation chamber 92 and the filter plate 8 is established. Steam is discharged through the channel on one side of the plate frame 81, causing the filter plate 82 to flip. Through the impact teeth 822, it collides with the adjacent filter plate 82, cleaning the dust accumulated on the surface. As the steam is discharged, the air pressure in the evaporation chamber 92 drops, disconnecting the air connection between the evaporation chamber 92 and the filter plate 8. After the filter plate 8 is cleaned, it resets, and the dust falls into the lower dust collection tray 10 for collection.

Claims

1. A rotary kiln main kiln for processing NdFeB waste, characterized in that, include: A kiln tube (3) is installed between the kiln head (1) and the kiln tail smoke chamber (2) at an angle and rotates. A drive mechanism (4) is installed below the kiln tube (3) to drive the kiln tube (3) circumferentially. Fuel bin (5) is connected to the kiln head (1) for combustion and energy supply; Blower (6): A blower (6) is installed on one side of the kiln head (1) to blow air into the kiln tube (3), thereby transferring heat and also discharging the smoke and dust generated during sintering. Feed hopper (7), the top of the end of the kiln tail smoke chamber (2) near the kiln tube (3) is provided with a feed hopper (7) extending into the kiln tube (3) for the introduction of waste material; The exhaust pipe (11) is provided on one side of the feed hopper (7) and connected to the kiln tail smoke chamber (2). At the connection between the exhaust pipe (11) and the kiln tail smoke chamber (2), there is a filter plate (8) composed of a rotating filter plate (82). The filter plate (8) is self-cleaned by the steam driven mechanism (9) in the kiln tail smoke chamber (2) to flip and collide with each other. The filter plate (8) includes a frame (81) and a filter plate (82). The frame (81) is a rectangular frame structure and is fixed to the bottom of the flue pipe (11). The filter plates (82) are rotatably arranged in the frame (81) at intervals. A steam channel connected to the waste heat drive mechanism (9) is provided on one side of the frame (81). One end of the filter plate (82) extends into the steam channel and is connected to a drive impeller (83). The filter plate (82) is rotated by the steam flow. An elastic element (84) is provided at the connection between the filter plate (82) and the frame (81) to limit the initial angle of the filter plate (82) between the filter plate (82) and the frame (81). The filter plate (82) includes an air-impact plate (821) and impact teeth (822). The air-impact plate (821) is a sheet-like plate structure. Two sets of impact teeth (822) are provided on the surface of the air-impact plate (821). The impact teeth (822) are symmetrically arranged along the central axis of the air-impact plate (821), and the impact teeth of adjacent air-impact plates (821) are staggered. The waste heat drive mechanism (9) includes: The preheating plate (91) is set as a cavity structure and fixed on both sides of the kiln tail smoke chamber (2), and one side is connected to a water inlet pipe for preheating the water liquid; Evaporation chamber (92), the kiln tail smoke chamber (2) and the kiln tube (3) are fixed with evaporation chamber (92), evaporation chamber (92) and preheating plate (91) are both cavity structures and are connected to each other for steam storage. The tail of evaporation chamber (92) is provided with water outlet. The top of the evaporation chamber (92) is equipped with a pressure cylinder (93) that is connected to the filter plate (8). The pressure cylinder (93) is a hydraulic cylinder structure with initial pressure. The pressure is controlled to open and close the air passage according to the pressure and to accumulate pressure.

2. The rotary kiln main kiln for processing NdFeB waste according to claim 1, characterized in that: The evaporation chamber (92) is an arc-shaped plate, and the corresponding arc-shaped edges are located at the corresponding positions of the preheating plates (91) on both sides.

3. The rotary kiln main kiln for processing NdFeB waste according to claim 1, characterized in that: The preheating plate (91) includes: An isolation channel is provided along the inner edge of the preheating plate (91) and the joint edge of the evaporation chamber (92), and the connection between the preheating plate (91) and the evaporation chamber (92) is located in the isolation channel; The heat absorption channel is arranged in an S-shape in the preheating plate (91), except for the isolation channel. The two ends are connected to the water inlet and one end of the isolation channel, respectively.

4. The rotary kiln main kiln for processing NdFeB waste according to claim 1, characterized in that: The accumulator cylinder (93) includes a connecting cylinder (931) and an accumulator cylinder (934) connected by a connecting seat (935). A first slider (932) and a second slider (936) are respectively provided in the connecting cylinder (931) and the accumulator cylinder (934). Oil is injected between the first slider (932) and the second slider (936) for hydraulic transmission. A duct (933) connected to the filter plate (8) is provided on the side of the connecting cylinder (931). A pressure spring (937) is provided between the second slider (936) and the accumulator cylinder (934) to indirectly act on the first slider (932) so that the first slider (932) always maintains a downward movement to block the opening of the duct (933).

5. The rotary kiln main kiln for processing NdFeB waste according to claim 4, characterized in that: The accumulator cylinder (93) also includes: The adjusting bolt (938) is threadedly connected to the connecting cylinder (931) on the connecting seat (935) and the accumulator cylinder (934) to control the flow of the connecting channel.

6. The rotary kiln main kiln for processing NdFeB waste according to claim 4, characterized in that: The first slider (932) includes a switching body (9321) and a delay slider (9322). The switching body (9321) is slidably disposed in the connecting cylinder (931) to control the opening and closing of the gas guide pipe (933). The side of the switching body (9321) corresponding to the gas guide pipe (933) is recessed with a strip-shaped groove distributed along the sliding direction of the switching body (9321). The bottom of the groove has a channel communicating with the evaporation chamber (92). A delay slider (9322) with a length shorter than the groove is slidably disposed in the groove.

7. The rotary kiln main kiln for processing NdFeB waste according to claim 1, characterized in that: A pull-out ash collection tray (10) is provided on one side of the kiln tail smoke chamber (2) below the filter plate (8).

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