Intermediate frequency induction heating continuous magnetic powder hydrogen absorption and desorption integrated furnace

Abstract

This invention discloses a medium-frequency induction heating continuous magnetic powder hydrogen absorption and dehydrogenation integrated furnace. The hydrogen absorption unit includes a rotatable hydrogen absorption furnace chamber, with an inlet and outlet box at the neck of the chamber. The inlet of the inlet and outlet box feeds material into the neck of the hydrogen absorption furnace chamber through a first feeder. The dehydrogenation unit includes a rotatable dehydrogenation furnace chamber, with the inlet of the dehydrogenation furnace chamber connected to the inlet box. The inlet of the inlet box feeds material into the dehydrogenation furnace chamber through a second feeder, and the inlet of the second feeder is connected to the outlet of the inlet and outlet box. The dehydrogenation furnace chamber is inclined, with its inlet higher than its outlet. The outlet of the dehydrogenation furnace chamber is connected to an outlet box, which discharges material from the dehydrogenation furnace chamber through a discharge device. The outlet of the outlet box is connected to a discharge tank. The dehydrogenation furnace chamber is heated by a heating unit. The dehydrogenation furnace chamber is in a vacuum state during the feeding, dehydrogenation, and discharging processes. The dehydrogenation furnace chamber is wrapped with an aluminum silicate fiber layer and an aerogel layer of insulation material, and the external temperature is much lower than the combustion and explosion temperature of hydrogen.

Description

Technical Field

[0001] This invention belongs to the field of rare earth permanent magnet hydrogen treatment technology, and relates to hydrogen crushing furnace, specifically a medium-frequency induction heating continuous magnetic powder absorption and dehydrogenation integrated furnace. Background Technology

[0002] In the hydrogen crushing process of rare earth permanent magnet materials, existing hydrogen treatment equipment typically suffers from the following problems: (1) Material agglomeration leads to incomplete dehydrogenation: Existing equipment generally lacks an effective material crushing mechanism. During the high-temperature dehydrogenation process, fine powder particles are very prone to thermal sintering, which causes the material powder to stick together to form lumps. After agglomeration, the particle size of the material increases and a thick atomic structure is formed inside, which makes the path of hydrogen atoms migrating from the inside of the material longer, making it difficult for hydrogen atoms to be released from the inside of the material powder, resulting in low dehydrogenation efficiency.

[0003] (2) Low thermal energy utilization: Existing technologies are mostly single heat sources, relying on external heating of resistance wires. In this process, heat needs to be conducted to the material through the furnace wall. The heat conduction path is long and a large amount of energy is lost to the surrounding environment during the transfer process, resulting in low thermal energy utilization.

[0004] (3) Uneven heating of materials: Traditional processes rely on external heating of resistance wires. Due to the poor thermal conductivity of powder materials, the surface of the material pile is often overheated while the center is underheated.

[0005] (4) Long heating cycle of materials: In traditional processes, heat mainly relies on external heat sources to conduct heat to the material layer in one direction through the furnace wall. Due to the high bulk density of powder materials and the high thermal resistance between particles, the heat needs to be conducted from the furnace surface to the center of the material pile for a long time.

[0006] (5) Poor consistency of material particle size: In the existing process, the shape of the material is usually maintained as an irregular polygon after crushing, and the particle size distribution range of the powder is relatively wide, with large particles and small particles mixed together, resulting in poor consistency of particle size.

[0007] (6) Uneven dehydrogenation of materials: Because the materials are irregular polygonal, the physical distances at which hydrogen atoms diffuse outward from the inside of the materials are different. In the same amount of time, small particles have been dehydrogenated excessively, while large particles still have a large number of hydrogen atoms remaining in the center. The degree of dehydrogenation of the material powder is different.

[0008] (7) High system energy consumption: Current hydrogen absorption and dehydrogenation equipment usually adopts a horizontal layout, and the transfer of materials between processes requires the use of conveyor belts or other mechanical conveying equipment. This not only increases the additional power consumption of the equipment and the machine maintenance cost, but also the heat energy generated by the hydrogen absorption reaction is often directly discharged by cooling water and is not effectively recovered, resulting in serious energy waste.

[0009] (8) Insufficient exposure of materials during dehydrogenation: During the dehydrogenation stage, traditional equipment can achieve axial material conveying, but it is difficult to ensure that the material is fully dispersed in the furnace cavity, and the powder cannot be fully exposed, which slows down the reaction progress.

[0010] Currently, all NdFeB hydrogen treatment furnaces used domestically and internationally operate as single furnaces. Each furnace requires processes such as feeding, vacuuming, hydrogen filling, heating and dehydrogenation, cooling, inert gas filling, and unloading. The heating temperature is around 600 degrees Celsius. Because the furnace must be opened during cooling and a gap must be left for the furnace chamber to rotate, the furnace cannot be strictly sealed, making open flames from the heating wires unavoidable, which does not meet the requirements of GB50058 "Design Code for Electrical Installations in Explosive Atmospheres". Furthermore, the operation is complex and labor costs are high. In addition, the continuous heating and cooling of the furnace increases energy consumption, especially since the furnace chamber is also constantly heated and cooled, causing thermal fatigue and severely shortening its service life. Therefore, it is necessary to improve the existing technology. Summary of the Invention

[0011] To overcome the shortcomings of existing technologies, a medium-frequency induction heating continuous magnetic powder dehydrogenation integrated furnace is provided.

[0012] This invention is achieved using the following technical solution: A medium-frequency induction heating continuous magnetic powder hydrogen absorption and dehydrogenation integrated furnace includes a hydrogen absorption unit and a hydrogen dehydrogenation unit. The hydrogen absorption unit includes a rotatable hydrogen absorption furnace chamber, and the neck of the hydrogen absorption furnace chamber is provided with an inlet and outlet box. The inlet of the inlet and outlet box feeds material into the neck of the hydrogen absorption furnace chamber through a first feeder. The dehydrogenation unit includes a rotatable dehydrogenation furnace chamber. The inlet of the dehydrogenation furnace chamber is connected to a feed box, which feeds material into the dehydrogenation furnace chamber via a second feeder. The inlet of the second feeder is connected to the outlet of the feed-discharge box. The dehydrogenation furnace chamber is inclined, with its inlet higher than its outlet. The outlet of the dehydrogenation furnace chamber is connected to a discharge box, which discharges material from the dehydrogenation furnace chamber via a discharge device. The outlet of the discharge box is connected to a discharge tank. The dehydrogenation furnace chamber is heated by a heating unit. The dehydrogenation furnace chamber is under vacuum during the feeding, dehydrogenation, and discharging processes.

[0013] During operation, the hydrogen absorption furnace is rotated, the first feeder is started, and after feeding is complete, the first feeder is withdrawn. The vacuum pump is then started to evacuate the hydrogen absorption unit. Once the vacuum level reaches 1 Pa, the vacuum pump is turned off, and hydrogen is then introduced into the hydrogen absorption furnace. The hydrogen reacts with the raw material (neodymium iron boron). After hydrogen absorption is complete, the hydrogen absorption furnace is reversed, and the absorbed powder falls into the second feeder by gravity through the inlet and outlet boxes at the neck. The second feeder completes the feeding of the dehydrogenation furnace, maintaining a vacuum state throughout the operation. As the magnetic powder slides forward in the heating section of the furnace, the powder layer gradually thins, eventually entering the outlet and being discharged through the discharge device into a vacuum discharge tank.

[0014] More preferably, the hydrogen absorption furnace is located in a cooling water tank. Hydrogen absorption is an exothermic reaction, and the hydrogen absorption furnace is immersed in the cooling water tank to achieve rapid cooling.

[0015] More preferably, in order to maintain a vacuum state during the hydrogen absorption process, the feed box is equipped with a vacuuming and hydrogen gas interface.

[0016] More preferably, the neck and body of the hydrogen absorption furnace are equipped with spiral blades, which realize feeding and discharging by forward and reverse rotation.

[0017] The first feeder is a vibrating feeder. The feed pipe of the vibrating feeder extends into the inlet of the feed hopper and feeds material while the hydrogen absorption furnace is rotating. The inlet of the vibrating feeder is connected to the bottom outlet of the raw material tank. The first feeder and the feed hopper work together to feed the hydrogen absorption furnace.

[0018] More preferably, the heating section of the dehydrogenation furnace is covered with an insulation layer; the insulation layer is composed of a composite of an aluminum silicate fiber layer and an aerogel layer; the insulation layer rotates with the dehydrogenation furnace.

[0019] The heating unit is an induction coil arranged outside the dehydrogenation furnace chamber. The induction coil is connected to a medium-frequency induction power supply, and the induction coil is fitted with the insulation layer with a gap. Using induction heating, the dehydrogenation furnace chamber serves as both a vacuum container and a heating element. The outer layer is covered with insulation material, which reduces heat radiation, saves energy, and effectively solves the problem of open flames in existing technologies. The furnace chamber cooling section is equipped with a cooling unit that uses rain-type cooling, ensuring continuous heating and dehydrogenation in the dehydrogenation section and continuous cooling in the cooling section.

[0020] More preferably, to better assemble the feeding box and achieve feeding into the dehydrogenation furnace chamber, a first sealed bearing is fitted outside the inlet of the dehydrogenation furnace chamber, and the feeding box is sealed to the outer ring of the first sealed bearing; the second feeder seal passes through the feeding box and extends into the inlet of the dehydrogenation furnace chamber; the inlet of the second feeder is connected to the outlet of the feeding box through a feeding pipe, and a clamping valve is installed on the feeding pipe; the feeding box is provided with a vacuum interface to keep the feeding process in a vacuum state.

[0021] More preferably, a preheating pipe is pre-embedded in the insulation layer, and the preheating pipe is connected to the cooling water tank to realize the secondary utilization of heat.

[0022] More preferably, the inner wall of the heating section of the dehydrogenation furnace is provided with a spiral array of baffles to promote uniform dispersion of powder.

[0023] More preferably, in order to better assemble the discharge box and realize discharge, a second sealed bearing is assembled on the outside of the outlet of the dehydrogenation furnace, and the discharge box is sealed to the outer ring of the second sealed bearing; The discharge device is a spiral discharge device, and a spiral blade segment is provided on the central shaft of the spiral discharge device. The spiral blade segment is located in the outlet of the dehydrogenation furnace. The discharge end of the dehydrogenation furnace is provided with a discharge inclined plate. The central shaft is sealed through the discharge box and connected to the output end of the reducer through a coupling.

[0024] More preferably, in order to achieve discharge under vacuum, a clamping valve and a tank valve are sequentially provided between the outlet of the discharge box and the discharge tank; a vacuum and inert gas connection is provided between the clamping valve and the tank valve.

[0025] More preferably, in order to control the distance between two batches of material, a material level sensor is provided on the dehydrogenation furnace at least 1m away from its inlet; the furnace body heating section of the dehydrogenation furnace is provided with multiple thermocouple sensors.

[0026] More preferably, to achieve slow sliding of the material from the inlet to the outlet within the dehydrogenation furnace, the horizontal inclination angle of the dehydrogenation furnace is 1-5°, and the material movement speed within the dehydrogenation furnace is 1-3 meters per hour. To achieve stable discharge, the diameter of the outlet of the dehydrogenation furnace is more than 1 / 4 of the furnace body diameter.

[0027] The technical solution provided by this invention has the following advantages compared with the prior art: First, the device uses an intermittent hydrogen absorption and continuous hydrogen dehydrogenation method to achieve continuous production and improve production efficiency.

[0028] Secondly, the powder absorbed by the device falls through pipes and clamp valves to the second feeder below and is fed into the dehydrogenation furnace, so that the discharge of the hydrogen absorption unit and the feed of the dehydrogenation unit are on the same side, reducing the size of the device and saving costs.

[0029] Third, the device wraps the heating part of the furnace with insulation material and fixes the induction coil on the outside to achieve heating; a water spray cooling device and a water receiving tank are installed on the side near the discharge device; it not only solves the problem of open flame in the existing technology, but also ensures that the dehydrogenation section is always heated for dehydrogenation and the cooling section is always cooled.

[0030] Fourth, in this device, the powder is heated and cooled, and when it reaches the end of the dehydrogenation furnace, it is sent to the outlet of the furnace through the discharge ramp. After being discharged by the discharge device, it falls into the discharge tank, and vacuum discharge is achieved.

[0031] Fifth, this device employs induction coil heating at medium frequency. A magnetic field acts on the metal furnace lining, generating thermal radiation and heat conduction through the furnace wall. Simultaneously, the magnetic field penetrates the inner wall of the furnace and directly acts on the magnetic powder, generating an internal heat source. Furthermore, utilizing the skin effect of the magnetic powder surface in a medium-frequency magnetic field, energy density is concentrated at the geometric edges and irregular corners of the particles. Beneficial effects: This scheme firstly provides three heating paths simultaneously: furnace wall radiation heating, furnace wall conduction heating, and medium-frequency magnetic field induction heating, significantly improving thermal energy utilization and heating efficiency. Secondly, it achieves the ablation of irregular corners in the powder material, promoting the evolution of powder particles into spherical shapes, thereby minimizing the average distance hydrogen atoms diffuse to the surface and significantly improving the dehydrogenation reaction rate. Finally, in a medium-frequency magnetic field, the magnetic characteristics of the powder enable it to absorb magnetic field energy and convert it into heat energy; and the spherical magnetic powder has a significantly increased specific surface area, allowing heat to penetrate the particles from all directions, thus improving the heat absorption efficiency of the magnetic powder.

[0032] Sixth, the device features an inclined furnace body and a spatial spiral array of baffles: the dehydrogenation furnace is placed at a certain angle, and baffles arranged in a spatial spiral array along the furnace's axial direction are installed on the inner wall of the furnace. The rotation of the furnace guides the powder to generate a periodic cyclical motion of lifting, falling, and catching. During this cyclical motion, the instantaneous impact force of the material falling under its own weight is fully utilized to physically break up large lumps / particles, effectively suppressing the tendency of thermal sintering and agglomeration of the powder during high-temperature dehydrogenation, ensuring the uniformity of powder particle size and the overall uniformity of dehydrogenation of the batch. Furthermore, the spiral periodic throwing motion of the powder within the furnace promotes uniform dispersion, thus fully exposing the powder within the furnace and promoting heat absorption.

[0033] Seventh, the vertical layout of the hydrogen absorption furnace and dehydrogenation furnace: The hydrogen absorption furnace and its neck are equipped with reversible spiral blades, enabling powder feeding and discharging operations. Furthermore, the hydrogen absorption furnace and dehydrogenation furnace are arranged vertically. The spiral blades in the hydrogen absorption furnace and its neck operate with low power consumption, pushing the reacted powder horizontally to the discharge port. Subsequently, the powder falls naturally under gravity, directly entering the dehydrogenation furnace's feeding pipe through the inlet and outlet boxes. This vertical layout of the hydrogen absorption furnace and dehydrogenation furnace utilizes the free-fall motion of the powder to achieve material transfer between processes. It completely eliminates the mechanical drive mechanism required by traditional horizontal conveyor lines, significantly reducing energy consumption and equipment maintenance costs during material transfer.

[0034] Eighth, waste heat recovery from hydrogen absorption: The hot water generated from hydrogen absorption is introduced into the internal preheating pipes of the insulation layer of the dehydrogenation furnace to preheat the furnace body. The waste heat generated from hydrogen absorption is transferred to the dehydrogenation furnace through cooling water to provide preheating, realizing the step-by-step utilization of energy, shortening the preheating time of the dehydrogenation furnace and reducing power consumption.

[0035] This invention is reasonably designed and has great practical application value. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram showing the overall structure of the present invention.

[0039] Figure 2 This is a schematic diagram of the front part of the present invention.

[0040] Figure 3 This diagram illustrates the hydrogen absorption unit in this invention.

[0041] Figure 4 This is a schematic diagram of the front part of the dehydrogenation unit.

[0042] Figure 5 This is a schematic diagram of the rear of the dehydrogenation unit.

[0043] Figure 6 express Figure 2 Enlarged view of section A.

[0044] Figure 7A schematic diagram showing the spiral blades in the hydrogen absorption furnace chamber.

[0045] Figure 8 A schematic diagram showing the spiral array of baffles on the inner wall of the heating section of the dehydrogenation furnace.

[0046] In the diagram: 100-Hydrogen absorption unit, 101-Hydrogen absorption furnace chamber, 102-Neck, 103-Inlet / outlet box, 104-First feeder, 105-Vacuuming and hydrogen interface, 106-Spiral blades, 107-Feeding pipe, 108-Cooling water tank, 109-Raw material tank; 200-Dehydrogenation unit, 201-Dehydrogenation furnace chamber, 202-Inlet section, 203-Outlet section, 204-Inlet box, 205-Second feeder, 206-Outlet box, 207-Outlet device, 208-Outlet material tank, 209-Alumina silicate fiber layer, 210-Gas condenser Adhesive layer, 211-Induction coil, 212-Spray pipe, 213-Water receiving tank, 214-First sealed bearing, 215-Feeding pipe, 216-Pipe clamp valve, 217-Vacuum interface, 218-Central shaft, 219-Helical blade segment, 220-Discharge inclined plate, 221-Reducer, 222-Motor, 223-Tank valve, 224-Vacuum and inert gas connection pipe, 225-Level sensor, 226-Thermocouple sensor, 227-Second sealed bearing, 228-Support ring, 229-Support wheel assembly, 230-Pulley. Detailed Implementation

[0047] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0048] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0049] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0050] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] A medium-frequency induction heating continuous magnetic powder hydrogen absorption and dehydrogenation integrated furnace includes a hydrogen absorption unit 100 and a dehydrogenation unit 200.

[0052] like Figure 1 , Figure 3 As shown, the hydrogen absorption unit 11 includes a rotatable hydrogen absorption furnace chamber 101. The neck 102 of the hydrogen absorption furnace chamber 101 is provided with an inlet / outlet box 103. The inlet of the inlet / outlet box 103 feeds material into the neck 102 of the hydrogen absorption furnace chamber 101 through a first feeder 104. The inlet / outlet box 103 is provided with a vacuum and hydrogen interface 105.

[0053] In this embodiment, spiral blades 106 are provided in both the neck and the body of the hydrogen absorption furnace liner 101, such as... Figure 7 As shown. The rotation method of the hydrogen absorption furnace 101 is prior art. For example, the neck 102 and tail 111 of the hydrogen absorption furnace 101 are supported on the support frame by rotation (e.g., using bearings or support roller assemblies). The neck of the hydrogen absorption furnace 101 is equipped with a third sealed bearing 112, and the inlet / outlet box 103 is fixedly mounted on the outer ring of the sealed bearing 112. The hydrogen absorption furnace 101 is provided with a synchronously rotating sprocket, which is driven by an external drive unit through chain drive. The hydrogen absorption furnace 101 is located in the cooling water tank 108. The first feeder 104 is a vibrating feeder, which is a prior art structure. The vibrating feeder moves on the guide rail. In the unloaded state, the inlet of the inlet / outlet box 103 is sealed by the sealing plate 110. When loading, the sealing plate 110 is removed, and the feeding pipe 107 of the vibrating feeder extends into the inlet of the inlet / outlet box 103. At this time, the inlet of the vibrating feeder is connected to the bottom outlet of the raw material tank 109. While the hydrogen absorption furnace chamber 101 is rotating, the vibrating feeder feeds the material, and the hydrogen absorption furnace chamber 101 is fed by the spiral blades 106 while rotating.

[0054] like Figure 1 , Figure 2As shown, the dehydrogenation unit 200 includes a rotatable dehydrogenation furnace 201. The inlet 202 of the dehydrogenation furnace 201 is connected to a feed box 204. The feed box 204 feeds material into the dehydrogenation furnace 201 through a second feeder 205. The inlet of the second feeder 205 is connected to the outlet of the feed-discharge box 103. The design feature is that the outlet of the hydrogen absorption unit 100 and the inlet of the dehydrogenation unit 200 are located on the same side. The dehydrogenation furnace 201 is inclined, and its inlet 202 is higher than its outlet 203. The outlet 203 of the dehydrogenation furnace 201 is connected to a discharge box 206. The discharge box 206 discharges material from the dehydrogenation furnace 201 through a discharger 207. The outlet of the discharge box 204 is connected to a discharge tank 208. The dehydrogenation furnace 201 is heated by a heating unit. The dehydrogenation furnace 201 is in a vacuum state during the feeding, dehydrogenation, and discharging processes.

[0055] In this embodiment, the dehydrogenation furnace liner 201 adopts a conventional rotation method. For example, support rings 228 are set on at least the front and rear parts of the dehydrogenation furnace liner 201 and supported on the support wheel assembly 229. Then, a sprocket is coaxially provided on the front or rear end of the dehydrogenation furnace liner 201. The rotation of the dehydrogenation furnace liner 201 is driven by a motor through chain drive. Figure 4 As shown, a first sealed bearing 214 is externally mounted on the inlet 202 of the dehydrogenation furnace 201. The feed box 204 is sealed to the outer ring of the first sealed bearing 214, thus communicating with the inlet 202 of the dehydrogenation furnace 201. A vacuum port 217 is provided on the feed box 204. The second feeder 205 is a screw feeder, which is existing technology. This screw feeder passes through the feed box 204 in a sealed manner (a sealing plate is provided at the passage) and extends into the inlet of the dehydrogenation furnace 201. The inlet of the second feeder 205 is connected to the outlet of the feed box 103 through a feeding pipe 215, and a clamp valve 216 is installed on the feeding pipe 205. A shut-off valve is also installed at the outlet of the feed box 103.

[0056] like Figure 5As shown, a second sealed bearing 227 is externally mounted on the outlet 203 of the dehydrogenation furnace 201. The discharge box 206 is sealed to the outer ring of the second sealed bearing 227, thus communicating with the outlet 203 of the dehydrogenation furnace 201. The discharge device 207 is a screw discharge device. A spiral blade segment 219 is provided on the central shaft 218 of the screw discharge device. This spiral blade segment 219 is located inside the outlet 203 of the dehydrogenation furnace 201. The discharge end of the dehydrogenation furnace 201 is provided with a discharge inclined plate 220, which cooperates with the spiral blade segment 219 to achieve discharge. The central shaft 218 passes through the discharge box 206 in a sealed manner (a sealing plate is provided at the passage) and is connected to the output end of the reducer 221 via a coupling. The reducer 221 is connected to the motor 222. By designing an independently driven motor and reducer at the discharge end, the diameter of the outlet section (spiral blade segment 219) of the dehydrogenation furnace 201 is more than 1 / 4 of the furnace body diameter, achieving a discharge speed greater than the feeding speed. A clamp valve 216 and a tank valve 223 are sequentially installed between the outlet of the discharge box 206 and the discharge tank 208; a vacuum and inert gas connection pipe 224 is located between the clamp valve 216 and the tank valve 223.

[0057] like Figure 1 , Figure 2 As shown, the heating section of the dehydrogenation furnace 201 is covered with an insulation layer. This insulation layer is composed of an aluminum silicate fiber layer 209 and an aerogel layer 210, with a cloth strip wrapped around the outermost layer, rotating with the furnace. The heating unit is an induction coil 211 located outside the furnace of the dehydrogenation furnace 201. The induction coil 211 is connected to a medium-frequency induction power supply, and the induction coil 211 is fitted with the insulation layer with a gap. The heating area is tightly wrapped with insulation material, and the temperature of the exposed metal parts of the furnace is below 100 degrees Celsius, far below the ignition temperature of hydrogen (approximately 570 degrees Celsius). The temperature of the entire equipment does not exceed 100 degrees Celsius, meeting the requirements of GB50058 "Design Code for Electrical Installations in Explosive Atmospheres," and the external temperature is far below the combustion and explosion temperature of hydrogen.

[0058] like Figure 1 As shown, the furnace cooling section of the dehydrogenation furnace 201 is equipped with a cooling unit, including a spray pipe 212 located above the furnace and a water receiving tank 213 located below the furnace.

[0059] like Figure 2 , Figure 6 As shown, a material level sensor 225 is installed on the dehydrogenation furnace liner 201 at least 1m away from its inlet.

[0060] like Figure 1 , Figure 2 As shown, the furnace heating section of the dehydrogenation furnace 201 is equipped with multiple thermocouple sensors 226.

[0061] The horizontal tilt angle of the dehydrogenation furnace chamber 201 is 1-5°, and the actual design in this embodiment is 3 degrees. The rotation speed is 10 revolutions per hour. During rotation, the material slides downward slowly. The actual design moving speed is 1-3 meters per hour.

[0062] Preheating pipes are embedded in the insulation layer, preferably in the aluminum silicate fiber layer. These pipes fit the outer wall of the furnace heating section. After the hydrogen absorption furnace 101 reacts, the cold water entering the cooling water tank 108 absorbs heat and its temperature rises. The water is then discharged from the drain of the cooling water tank 108 and flows into the preheating pipes to preheat the furnace heating section of the dehydrogenation furnace 201, thus achieving secondary utilization of energy.

[0063] like Figure 8 As shown, the inner wall of the heating section of the dehydrogenation furnace 201 is equipped with helical array-arranged baffles 230. The dehydrogenation furnace is placed at a certain angle, and the baffles, arranged in a helical array along the furnace body axis, guide the powder to generate a periodic cyclical motion of lifting, falling, and catching through the rotation of the furnace body. This fully utilizes the instantaneous impact force of the material falling under its own weight to achieve physical breakage of lumps / large particles, effectively suppressing the tendency of thermal sintering and agglomeration of the powder during the high-temperature dehydrogenation process, ensuring the uniformity of powder particle size and the uniformity of dehydrogenation of the entire batch of powder. Furthermore, the helical periodic throwing motion of the powder within the furnace promotes uniform dispersion of the powder, thereby fully exposing the powder within the furnace body and promoting heat absorption.

[0064] The steps are as follows: Step 1: Insert the feeding pipe 107 of the first feeder 104 (vibrating feeder) into the inlet / outlet box 103 and add raw materials into the rotating hydrogen absorption furnace 101; after feeding is completed, remove the feeder and seal the inlet with the sealing plate 110; after evacuating the system through the interface 105, fill it with hydrogen. The hydrogen absorption furnace 101 rotates continuously in the cooling water tank 108 to carry out the hydrogen absorption reaction, and the circulating cooling water carries away the heat released by the reaction. Step 2: After the hydrogen absorption reaction is completed and the material temperature drops to a suitable temperature, open the clamp valve 216 on the connecting pipe to control the hydrogen absorption furnace chamber 101 to reverse; the material in the chamber is transported to the neck 102 under the action of the spiral blades 106, and falls into the feeding pipe 215 by gravity and enters the second feeder 205. Step 3: Start the second feeder 205 (screw feeder) to continuously feed the material into the dehydrogenation furnace chamber 201; at the same time, maintain the system vacuum state through the vacuum interface 217 on the feed box 204; Step 4: Control the dehydrogenation furnace 201 to rotate at a set speed, and use its tilt angle to make the material move slowly forward in the furnace; turn on the medium frequency induction power supply, and use the induction coil 211 to induction heat the material in the furnace through the insulation layer to dehydrogenate it. Step 5: The material moves to the cooling section at the end of the furnace chamber and is sprayed and cooled through the spray pipe 212. The cooled powder enters the spiral blade segment 219 at the outlet through the discharge inclined plate 220. Driven by the discharge device 207 (spiral discharge device), it falls into the discharge tank 208 through the discharge box 206, the clamp valve 216 and the tank valve 223. The discharge process is protected by vacuuming or filling with inert gas through the interface 224.

[0065] In practice, after inserting the first feeder 104 into the feed box 103, the inlet of the first feeder 104 is connected to the bottom outlet of the raw material tank 109. The hydrogen absorption furnace 101 is rotated to start the first feeder 104. After feeding is complete, the first feeder 104 is withdrawn. The insertion port of the feed box 103 is sealed using the sealing plate 110. The vacuum pump is started, and a vacuum is drawn using the vacuum and hydrogen interface 105 on the feed box 103. After the vacuum level reaches 1 Pa, the vacuum pump is turned off, and hydrogen gas at a pressure of 0.1 MPa is introduced using the same vacuum and hydrogen interface 105. After a few minutes, the hydrogen gas reacts with the raw material (neodymium iron boron), and the reaction is completed after 30-50 minutes. This exothermic reaction releases a large amount of heat, so throughout the process, the lower part of the hydrogen absorption furnace 101 is immersed in the cooling water tank 108. The cooling water is circulating water to improve heat dissipation efficiency. After hydrogen absorption is completed, cool for another 1-2 hours until the temperature drops below 60 degrees Celsius. Then, open the shut-off valve and clamp valve 216 on the feed pipe 107, reverse the hydrogen absorption furnace chamber 101, and the hydrogen-absorbed powder, under the action of the spiral blades and large inclined plate inside the chamber, falls into the feed pipe 107 by gravity after passing through the neck 102 and enters the second feeder 205.

[0066] After the discharge is completed, close the shut-off valve and clamp valve 216 on the feed pipe 107 to prepare for the next furnace hydrogen absorption.

[0067] The dehydrogenation furnace 201 is fed by the second feeder 205, with the feeding speed controlled so that the material layer height is approximately equal to the furnace radius. The feeder connects to the vacuum unit via the vacuum port 217 on the feed box 204, maintaining a vacuum state throughout operation at a vacuum level of 100-500 Pa. As the magnetic powder slides forward in the furnace heating section, the powder layer gradually thins. After dehydrogenation, it enters the cooling section, where it is cooled by water spray. Finally, it enters the spiral blade segment 219 of the outlet section 203 through the discharge ramp 220. Driven by the motor 222 and reducer 221, the powder passes through the discharge box 206, the clamp valve 216, and the material tank valve 223 into the vacuum discharge tank 208. The motor 222 and reducer 221 are located on a moving trolley, which moves along a guide rail. The spiral discharger has an independent rotation drive, with a rotation speed greater than the ratio of furnace diameter to discharge spiral diameter. Because the diameter of the rotary kiln chamber (1000mm) is much larger than that of the discharge outlet (260mm), the rotational speed of the central shaft 218 must be greater than 10*1000 / 260=38 revolutions per minute, with an actual operating speed of 200 revolutions per hour. Since the dehydrogenation unit operates under vacuum throughout the entire process, the discharge process also takes place under vacuum. Therefore, when changing the discharge tank 208, after connecting the discharge pipe, open the tank valve 223, connect the vacuum system via the vacuum pump and inert gas connection 224, and once the vacuum reaches 10Pa, open the clamp valve 216 to begin discharge. After discharge is complete, close the clamp valve 216, fill the tank with argon or nitrogen via the vacuum pump and inert gas connection 224, and then remove the discharge tank 208.

[0068] Because the feeding and discharging are intermittent, and to handle magnetic powders of different compositions, a sufficient interval must be maintained between the two batches to prevent mixing and allow enough time for discharging and changing the discharge bucket. The minimum distance between the two batches is controlled at 1m. A level sensor 225 is installed 1m from the inlet of the dehydrogenation furnace chamber 201. Before the next feeding, the feeding program is only started after verifying that there is no material at this point.

[0069] Furthermore, regarding valves, conventional ball valves and butterfly valves have extremely short lifespans due to the presence of metal powder. This invention employs a clamp valve tube and a ball-domed valve, resulting in a longer lifespan. A clamp valve is essentially a rubber tube of a certain thickness with clamping rods or blocks on the outside, closing the tube wall and preventing both powder and gas from passing through.

[0070] This invention has the following characteristics: 1. Suppressing agglomeration: The design of the rotating furnace body and the spiral array of baffles on the inner wall of the furnace body lifts the powder and breaks it down by its own weight, generating a periodic cycle of lifting-falling-catching. In this process, the agglomeration of unagglomerated powder is suppressed, while the agglomerated powder is disintegrated.

[0071] 2. Particle spheroidization: The skin effect generated by medium-frequency induction is used to concentrate the current on the particle surface, preferentially dissolving the sharp edges of irregular particles. Under this action, the particles gradually tend to become spherical.

[0072] 3. Promotes dehydrogenation: In the spherical structure, the distance from the inside to the particle surface is the shortest and relatively even in all directions, thereby reducing the average escape distance of hydrogen atoms and improving the dehydrogenation efficiency.

[0073] 4. Uniform Particle Size: Under the combined force of the rotating furnace body and the spiral array of baffles arranged along the inner wall of the furnace, the powder undergoes a spiral periodic throwing motion within the furnace. After falling, the material collides with the inner wall of the furnace, causing large lumps / particles to break up. At the same time, the skin effect dissolves the sharp edges of the particles. In this process, the particle size of the entire batch of powder tends to be uniform.

[0074] 5. Uniform dehydrogenation: When the powder particle size is basically the same, the distance of the hydrogen atom diffusion path within the particle is also basically the same, and the dehydrogenation effect of the whole batch of powder tends to be consistent, ensuring that the powder in the whole furnace can reach the dehydrogenation endpoint at the same time, thus improving the stability and consistency of the powder quality in the same batch.

[0075] 6. Triple heat source: Medium-frequency induction heating method: After the induction coil outside the dehydrogenation furnace is energized, it generates a medium-frequency magnetic field, which can be converted into heat energy through three paths: 1) Furnace wall radiant heating: Under a medium-frequency magnetic field, an induced current is generated inside the furnace wall. As the current flows inside the furnace, it generates heat, causing the furnace temperature to rise. When the furnace is heated to several hundred degrees Celsius, it will continuously emit infrared rays into the hollow part inside the furnace, and the infrared rays generate thermal radiation energy. The powder surface absorbs this radiation energy and converts it into heat energy, thereby raising the temperature of the powder.

[0076] 2) Conductive heating of furnace wall: In the medium frequency magnetic field, a large amount of heat energy is also accumulated in the heated inner wall of the furnace. When the powder rolls in the furnace or comes into contact with the inner wall of the furnace, it will absorb the heat of the inner wall of the furnace.

[0077] 3) Medium-frequency magnetic field induction heating: In a medium-frequency magnetic field, the alternating magnetic field generated by the induction coil has extremely strong penetrating power. This magnetic field can enter the furnace and affect the magnetic powder. The magnetic powder itself is conductive. When the magnetic field enters the powder particles, a current is induced inside the particles. Since there is resistance inside the particles, the flow of these currents generates heat, thus directly heating the powder particles. This heating method can achieve instantaneous heating and can heat all magnetic particles simultaneously, further improving heating efficiency.

[0078] The medium-frequency induction heating method provides three heating paths, which greatly improves the utilization rate of thermal energy and increases heating efficiency.

[0079] 7. Two heat absorption pathways: 1) Magnetic powder heat absorption: The magnetic characteristics of the powder enable it to absorb magnetic field energy and convert it into heat energy in a mid-frequency magnetic field. At the same time, the mid-frequency magnetic field has a skin effect on the irregular shape of the magnetic powder's tiny edges. After the tiny edges are dissolved, the magnetic powder tends to become spherical. After becoming spherical, the specific surface area of ​​the magnetic powder increases significantly, allowing heat to enter the interior of the particles from all directions, thereby improving the heat absorption efficiency of the magnetic powder.

[0080] 2) Fully exposed heat absorption: Under the combined force of the rotation of the furnace body and the spiral arrangement of the baffle array on the inner wall of the furnace, the powder makes a spiral periodic throwing motion in the furnace, which promotes the uniform dispersion of the powder and fully exposes the powder in the furnace body, thereby promoting the powder heat absorption.

[0081] 8. Reduce energy consumption: 1) Gravity Conveying: The hydrogen absorption furnace and its neck are equipped with reversible spiral blades, enabling powder feeding and discharging within the furnace. The hydrogen absorption furnace and dehydrogenation furnace are vertically integrated. The spiral blades in the hydrogen absorption furnace and its neck operate with low power consumption, pushing the reacted powder horizontally to the discharge port. Subsequently, the powder falls naturally under gravity, passing through the inlet and outlet boxes directly into the dehydrogenation furnace's feeding pipe. This vertical layout of the hydrogen absorption and dehydrogenation furnaces utilizes the free-fall motion of the powder to achieve vertical movement between processes, eliminating the need for conveyor belts and other structures required in traditional material handling, thus reducing energy consumption and machine costs during material transport.

[0082] 2) Waste Heat Utilization: During the hydrogen absorption process (exothermic reaction) in the hydrogen absorption furnace, a large amount of heat is released. This heat is carried away by the flowing water in the cooling water tank, causing the water temperature to rise and be discharged from the outlet. Through the control of a branch valve, the generated hot water is introduced into the internal piping of the dehydrogenation furnace's insulation layer to preheat the furnace body. This process utilizes the waste heat generated from hydrogen absorption to preheat the dehydrogenation process via cooling water transfer, achieving tiered energy utilization, shortening the preheating time of the dehydrogenation furnace, and reducing power consumption.

[0083] 9. During the material hoisting process, the material is automatically fed along the axial direction of the furnace body: As the furnace rotates, the spiral-arranged array of baffles continuously cuts into the bottom material layer, lifting the powder upwards. When the baffles rotate to a certain height, the material detaches from the baffles due to its own weight, scattering in a waterfall-like manner. The falling powder violently impacts the bottom of the furnace or the baffles below, converting gravitational potential energy into instantaneous impact force, breaking the powder while simultaneously causing it to move axially. The powder falling to the bottom of the furnace body is then caught by the baffles below, carrying it into the next cycle.

[0084] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A medium-frequency induction heating continuous magnetic powder hydrogen absorption and dehydrogenation integrated furnace, comprising a hydrogen absorption unit (100) and a dehydrogenation unit (200). Its features are: The hydrogen absorption unit (11) includes a rotatable hydrogen absorption furnace (101), and the neck (102) of the hydrogen absorption furnace (101) is provided with an inlet and outlet box (103). The inlet of the inlet and outlet box (103) feeds material to the neck (102) of the hydrogen absorption furnace (101) through a first feeder (104). The dehydrogenation unit (200) includes a rotatable dehydrogenation furnace chamber (201), the inlet (202) of which is connected to a feed box (204). The feed box (204) feeds material into the dehydrogenation furnace chamber (201) through a second feeder (205), the inlet of which is connected to the outlet of the feed box (103). The dehydrogenation furnace chamber (201) is inclined, and its inlet (202) is high. At the outlet (203); the outlet (203) of the dehydrogenation furnace (201) is connected to the discharge box (206), the discharge box (206) completes the discharge of the dehydrogenation furnace (201) through the discharge device (207), and the outlet of the discharge box (204) is connected to the discharge tank (208); the dehydrogenation furnace (201) is heated by the heating unit; the dehydrogenation furnace (201) is in a vacuum state during the feeding, dehydrogenation and discharge process.

2. The integrated furnace for continuous magnetic powder dehydrogenation with medium-frequency induction heating according to claim 1, characterized in that: The hydrogen absorption furnace liner (101) is provided with spiral blades (106) in the neck and inside the liner. The first feeder (104) is a vibrating feeder. The feeding pipe (107) of the vibrating feeder extends into the inlet of the feed box (103) and feeds the material while the hydrogen absorption furnace (101) is rotating. The inlet of the vibrating feeder is connected to the bottom outlet of the raw material tank (109). The hydrogen absorption furnace chamber (101) is located in the cooling water tank (108).

3. A medium-frequency induction heating continuous magnetic powder dehydrogenation integrated furnace according to claim 1 or 2, characterized in that: The heating section of the dehydrogenation furnace (201) is covered with an insulation layer, and the external temperature is much lower than the combustion and explosion temperature of hydrogen. The insulation layer is composed of an aluminum silicate fiber layer (209) and an aerogel layer (210). The heating unit is an induction coil (211) arranged outside the furnace shell of the dehydrogenation furnace (201). The induction coil (211) is connected to a medium-frequency induction power supply, and the induction coil (211) is fitted with the insulation layer with a gap. The dehydrogenation furnace (201) is equipped with a cooling unit in the furnace cooling section.

4. The integrated furnace for medium-frequency induction heating and continuous magnetic powder dehydrogenation according to claim 3, characterized in that: The inlet (202) of the dehydrogenation furnace (201) is equipped with a first sealed bearing (214), and the feed box (204) is sealed to the outer ring of the first sealed bearing (214); the second feeder (205) passes through the feed box (204) and extends into the inlet of the dehydrogenation furnace (201); the inlet of the second feeder (205) is connected to the outlet of the feed box (103) through the feed pipe (215), and the feed pipe (205) is equipped with a clamp valve (216); the feed box (204) is provided with a vacuum port (217).

5. The integrated furnace for continuous magnetic powder adsorption and dehydrogenation with medium-frequency induction heating according to claim 4, characterized in that: A preheating pipe is embedded in the insulation layer, and the preheating pipe is connected to the cooling water tank (108); The inner wall of the heating section of the dehydrogenation furnace (201) is provided with a spiral array of baffles (230).

6. The integrated furnace for continuous magnetic powder adsorption and dehydrogenation with medium-frequency induction heating according to claim 5, characterized in that: The outlet (203) of the dehydrogenation furnace (201) is equipped with a second sealed bearing (227), and the discharge box (206) is sealed to the outer ring of the second sealed bearing (227). The discharge device (207) is a spiral discharge device. The spiral discharge device has a spiral blade segment (219) on its central shaft (218). The spiral blade segment (219) is located in the outlet (203) of the dehydrogenation furnace (201). The discharge end of the dehydrogenation furnace (201) is provided with a discharge inclined plate (220). The central shaft (218) passes through the discharge box (206) and is connected to the output end of the reducer (221) through a coupling.

7. The integrated furnace for continuous magnetic powder adsorption and dehydrogenation with medium-frequency induction heating according to claim 6, characterized in that: The outlet of the discharge box (206) and the discharge tank (208) are connected in sequence by a clamp valve (216) and a tank valve (223); a vacuum and inert gas connection pipe (224) is provided between the clamp valve (216) and the tank valve (223).

8. The integrated furnace for continuous magnetic powder adsorption and dehydrogenation with medium-frequency induction heating according to claim 7, characterized in that: A level sensor (225) is provided on the dehydrogenation furnace (201) at least 1m away from its inlet; multiple thermocouple sensors (226) are provided in the furnace heating section of the dehydrogenation furnace (201).

9. A medium-frequency induction heating continuous magnetic powder dehydrogenation integrated furnace according to claim 8, characterized in that: The horizontal tilt angle of the dehydrogenation furnace (201) is 1-5°; the diameter of the outlet of the dehydrogenation furnace (201) is more than 1 / 4 of the furnace body diameter; the moving speed of the material inside the dehydrogenation furnace (201) is 1-3 meters / hour.

10. A medium-frequency induction heating continuous magnetic powder dehydrogenation integrated furnace according to claim 9, characterized in that: The feed box (103) is equipped with a vacuum and hydrogen interface (105).

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