NL2029924B1

NL2029924B1 - High-temperature planetary ball-milling device

Info

Publication number: NL2029924B1
Application number: NL2029924A
Authority: NL
Inventors: Lin Xiaochen; Zhao Zehua; Zhang Houhu; Zhang Dapeng; Xu Yuanshun; Ma Bing
Original assignee: Nanjing Institute Of Environmental Sciences Mini Of Ecology And Environment Of The Peoples Republic
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2023-06-16

Abstract

The present disclosure discloses a high-temperature planetary ball-milling device which includes a tray and a plurality of ball milling units. The tray is rotatable in a 5 horizontal plane; the ball milling unit includes an external frame, an inner cylinder, a planetary gear and a plurality of metal milling balls. The external frame includes a frame body, the frame body is provided on the tray and is rotatable relative to the tray. The planetary gear is ﬁxedly sleeved on the frame body, the planetary gear rotates, a rotation direction of the planetary gear is opposite to that of the tray, and the frame 10 body rotates in an opposite direction along with the planetary gear while revolving along with the tray. The inner cylinder includes a cylinder body which is vertically ﬁxed in the frame body. A thermal insulation layer is coated on an inner cylinder wall of the cylinder body. A wear-resistant layer is coated on the thermal insulation layer; a magnet yoke coil layer is further provided in the cylinder body and located outside the 15 thermal insulation layer or embedded in an outer side of the thermal insulation layer. The magnet yoke coil layer includes a magnet yoke and a coil, the coil is located inside the magnet yoke or embedded in an inner side of the magnet yoke. The coil is connected with a high-frequency power supply, and the plurality of metal milling balls are provided in the cylinder body. The present disclosure has the advantages of 20 accurate temperature control, high efﬁciency, energy conservation and the like.

Description

HIGH-TEMPERATURE PLANETARY BALL-MILLING DEVICE

TECHNICAL FIELD

[01] The present disclosure belongs to the technical field of powder processing mechanical equipment, and relates to a ball milling device, in particular to a high-temperature planetary ball-milling device.

BACKGROUND ART

[02] A planetary ball mill is key equipment in the field of manufacturing electronic raw materials and nanometer materials, and is also commonly used powder processing equipment widely used in biology, food, cosmetics, medicine, material, mining, metallurgy and other industries. The cylinder body revolves and rotates at a high speed, so as to result in shear and collision between steel balls or ceramic balls and raw materials, and realize crushing and milling of the materials. In a process of powder processing, it is often necessary to heat the powder prior to and subsequent to the milling process in order to achieve the effects of drying, high-temperature heat treatment or high-temperature reaction. In the prior art, milling and heating belong to two processes, at least two sets of equipment are needed, and the equipment occupies a large area. According to the properties of the powder to be processed, protective gas needs to be filled in some processing processes. The transportation and preservation of materials among multiple sets of equipment increases processes and cost. Integrating multiple processes can reduce the cost and improve the quality stability. In modern material preparation, a method of promoting a reaction rate by using high surface chemical energy at instant of particle breaking is provided. In order to make the reaction proceed smoothly, a temperature control is also needed. Furthermore, the existing planetary ball mill puts the raw materials into the cylinder body at one time, all of which are then poured out after being stirred and crushed. For heterogeneous raw materials with different particle sizes or hardness, before the large particles or hard particles reach the target particle size, small particles or soft particles will be excessively milled, resulting in poor uniformity in the particle size of products. The continuous powder processing and production method combining milling and heat treatment has a good application prospect and economic benefit, which can realize instant screening in the stirring process, avoid excessive milling, save energy consumption and improve product quality.

[03] Regarding combination of ball milling and heat treatment, the disclosures

CN100460074C and CN102614965B adopt a technical route of placing a ball mill in a high-temperature furnace. In the high temperature, all parts of the ball mill are easy to be damaged, especially driving and transmission parts. Moreover, the heating from outside to inside needs to heat the wall of the ball-milling cylinder first, and then the heating of the material is realized through the heat transfer between the wall of the cylinder and the material. The contact area between the wall of the cylinder and the material is limited, resulting in slow temperature rise and uneven heating of the material. In addition, the technology of placing a ball mill in a high-temperature furnace can only process materials in batches, and cannot realize continuous production. The disclosures CN107866312B and CN109282585B use hot gas to dry materials. However, due to the low specific heat of the gas, the energy that can be carried is limited. In actual production, the heating speed of gas is low, and the function of the gas is limited to drying, which cannot reach a higher temperature. The application publication No. CN109663639A proposes to use microwave for heating. In theory, materials can be directly heated, and the high-temperature pressure and heat loss caused by the cylinder body and the related driving and transmission parts are reduced. However, in the prior art, construction of large-scale microwave equipment and shielding of microwave radiation are extremely expensive, which is difficult to be used in large-scale production. Moreover, microwave heating can only be used for microwave sensitive materials, and the materials processed by the microwave heating are limited, the microwave heating is not universal.

SUMMARY

[04] In view of shortcomings of the existing high-temperature ball milling technology and equipment, the present disclosure provides a technology and a device equipment for heating metal milling balls by electromagnetic induction, which can continuously heat target materials efficiently, rapidly and uniformly inside an inner cylinder which is the closed space by utilizing contact between milling balls and materials during milling, thus realizing high-temperature ball milling processing under control of precise temperature and reaction atmosphere, and which can furthermore bring out the milled powder immediately through design of the gas channel so as to avoid excessive milling, further reducing energy consumption and improving product quality.

[05] In order to achieve the above objects, it is provided a high-temperature planetary ball-milling device, including a tray and a plurality of ball milling units. The tray is horizontally provided and is rotatable in a horizontal plane around a center thereof. Each ball milling unit includes an external frame, an inner cylinder, a planetary gear and a plurality of metal milling balls. The external frame includes a frame body, the frame body is provided on the tray and is rotatable relative to the tray.

Frame bodies of the plurality of ball milling units are uniformly distributed around the center of the tray. The planetary gear is fixedly sleeved on the frame body, the planetary gear rotates, and a rotation direction of the planetary gear is opposite to that of the tray, and the frame body rotates along with the planetary gear in a first direction while revolving along with the tray in a second direction opposite to the first direction.

The inner cylinder includes a cylinder body which is vertically fixed in the frame body and rotates along with the frame body. A thermal insulation layer is coated on an inner cylinder wall of the cylinder body, a wear-resistant layer is coated on an inner side of the thermal insulation layer. A magnet yoke coil layer is further provided in the cylinder body and located on an outer side of the thermal insulation layer or embedded in an outer side of the thermal insulation layer. The magnet yoke coil layer being embedded in the outer side of the thermal insulation layer means that the magnet yoke coil layer is shorter than the thermal insulation layer and the thermal insulation layer encloses the magnet yoke coil layer by the inner side, an upper side and a lower side thereof. The magnet yoke coil layer includes a magnet yoke and a coil. The coil is located inside the magnet yoke or embedded in an inner side of the magnet yoke. The coil being embedded in the inner side of the magnet yoke means that the coil is fixed within the magnet yoke and located in the inner side relative to the entire magnet yoke.

The coil is connected with a high-frequency power supply. The plurality of metal milling balls 1s provided in the cylinder body. Materials are placed into the cylinder body, and the metal milling balls grind the materials in the cylinder body that is rolling, and the coil is energized with high-frequency alternating current to generate an alternating magnetic field inside the cylinder body, so that surfaces of the metal milling balls are heated due to induced eddy current so as to heat the materials.

[06] Further, the magnet yoke coil layer is embedded in a portion of the thermal insulation layer on a side cylinder wall of the cylinder body. The coil is embedded in the inner side of the magnet yoke.

[07] Further, a center of a bottom of the frame body is provided with a frame rotating shaft protruding downward. The tray is provided with a plurality of rotating shaft holes penetrating through the tray, and a number of the rotating shaft holes is equal to a number of the ball milling units and the rotating shaft holes and the ball milling units are in one-to-one correspondence. The frame rotating shaft of the frame body of the ball milling unit passes through a corresponding rotating shaft hole and is relatively rotatable in the corresponding rotating shaft hole. The planetary gear is located below the tray and fixedly sleeved on a part of the frame rotating shaft protruding downward out of the tray.

[08] Further, the high-temperature planetary ball-milling device further includes a base and a main shaft. The main shaft is vertically provided on a bottom surface of the base and is capable of being driven to rotate by a driving device. The center of the tray is fixedly sleeved on the main shaft and rotates along with the main shaft.

[09] Further, a circle of internal gears 1s provided on an inner side wall of the base, located on outer sides of planetary gears of the plurality of ball milling units and meshed with the planetary gears. When the tray drives the planetary gears to revolve, the planetary gears rotate under action of the internal gears.

[10] Further, the high-temperature planetary ball-milling device further includes a gas inlet and outlet control system which is communicated with the inner cylinder of 5 the ball milling unit and controls gas to enter or exit the inner cylinder.

[11] Further, the inner cylinder further includes a cylinder cover which covers a top opening of the cylinder body in a sealed manner. The ball milling unit is provided with a gas inlet channel running through bottoms of the external frame and the inner cylinder and a gas outlet channel running through tops of the external frame and the ner cylinder. The gas enters the inner cylinder through the gas inlet channel and then is discharged through the gas outlet channel. The gas inlet and outlet control system includes a plurality of spherical cap-shaped cover plates which are provided in inner cylinders of the ball milling units in one-to-one correspondence; a port of the gas inlet channel is covered with a corresponding spherical cap-shaped cover plate, and each spherical cap-shaped cover plate is connected with a bottom surface of a corresponding inner cylinder through an elastic member. When a gas inlet pressure is greater than a pressure in the cylinder body, the spherical cap-shaped cover plate is pushed to open by the gas inlet pressure; and when the gas inlet pressure is less than the pressure in the cylinder body, the spherical cap-shaped cover plate is automatically closed by a restoring force of the elastic member.

[12] Further, the gas inlet and outlet control system further includes a gas inlet main channel and a plurality of gas inlet branch pipelines. The gas inlet main channel is provided at a bottom of the main shaft. A number of the gas inlet branch pipelines is equivalent to the number of the ball milling units, and the gas inlet branch pipelines and the ball milling units are in one-to-one correspondence, an end of each gas inlet branch pipeline is communicated with the gas inlet main channel and an other end thereof is communicated with a gas inlet channel of a corresponding ball milling unit through a first gastight bearing. The gas inlet and outlet control system further includes a gas outlet main channel and a plurality of gas outlet branch pipelines. The gas outlet main channel is provided at a top of the main shaft. A number of the gas outlet branch pipelines is equivalent to the number of the ball milling units, and the gas outlet branch pipelines and the ball milling units are in one-to-one correspondence, an end of each gas outlet branch pipeline is communicated with the gas outlet main channel and an other end thereof is communicated with a gas outlet channel of a corresponding ball milling unit through a second gastight bearing. The gas enters the device through the gas inlet main channel and is discharged through the gas outlet main channel. A port of the gas outlet channel is provided with a replaceable screen. When the gas is discharged, the milled fine particles are taken out of the gas outlet channel through the screen on the cylinder cover, while the coarse particles are blocked by the screen and kept in milling in the cylinder.

[13] Further, the gas inlet branch pipeline and the gas outlet branch pipeline are both provided with valves.

[14] Further, the external frame further includes a fastening bracket and a fastening screw, the fastening bracket is detachably fixed at an upper end of the frame body, the fastening screw passes through the fastening bracket with a lower end thereof abutting against the cylinder cover. The fastening screw is threadedly connected with the fastening bracket, the fastening screw is screwed to abut against the cylinder cover downwards to seal the inner cylinder.

[15] The present disclosure has the following beneficial effects.

[16] 1. The alternating magnetic field is generated inside the coil by using current, so that the metal milling ball generates induced eddy current heating, which directly acts on the material powder. The heat does not act on other parts of the device, thereby having a direct heating and a high energy efficiency.

[7] 2. The number of milling balls is large, the contact area between the milling balls and the material powder is large, the overturning vibration during ball milling further promotes the contact between the milling balls and the material powder, and the heat transfer is fast.

[18] 3. High-frequency power supply is adopted. Because of skin effect, the internal temperature of the metal ball is low, and the heating is concentrated on the ball surface, which is beneficial to heat transfer to the material powder. It is convenient to directly control the heating. When the power is cut off, the heating is stopped. No extra heat is stored in the steel ball, and the temperature control is accurate.

[19] 4. The coil is connected with an external power supply through a carbon brush, thus realizing stable connection under high-speed rotation.

[20] 5. Wear-resistant high-chromium steel or high-temperature ferromagnetic materials can be selected to manufacture the milling balls according to the purpose of drying materials or high-temperature reaction, which has a wide range of application temperature and can be universally applied to processing of various powder materials.

[21] 6. By integrating the power milling and heating processes, the intensification of the device is realized, and the area occupied by the device is reduced. Moreover, the compact device is beneficial to gas tightness control. The device can not only be processed in gas atmosphere, but also can be filled with protective gas or reaction gas as required, which has a wide application range.

[22] 7. Gastight bearings are used for the connection between the external frame and the gas inlet and outlet gas branch pipes, and the gas inlet and outlet gas branch pipes only participate in revolution and do not rotate along with the cylinder body, thus avoiding distortion of the pipelines caused by rotation.

[23] 8. The inner side of the gas inlet uses a spherical cap-shaped cover plate, and the gas does not escape from one point, but is ejected along the annular slit formed between the outer edge of the cover plate and the inner bottom plate of the cylinder body, so that the contact range between the gas and the material is greater.

[24] 9. The spherical cap-shaped cover plate can only be opened when the gas inlet pressure is sufficient. Once the gas inlet pressure is insufficient, the gas inlet will be automatically closed due to the elasticity to prevent the materials from entering or even blocking the gas inlet channel.

[25] 10. In the process of using the reactive gas to react with the materials, the gas passes through the materials from bottom to top, which ensures full contact between the gas and the materials and is beneficial to the reaction.

[26] 11. In the process of using the reactive gas to react with the materials, the materials are stirred and milled while being heated, which can continuously peel the reaction products on the surface layer from the particles, improve the uniformity and the reaction rate of high-temperature reaction, and improve the efficiency. Furthermore, the fresh surface exposed due to material crushing during the ball milling has a high surface energy and high reaction activity, which is beneficial to improve purity of the reaction products.

[27] 12. The insulation layer is between the coil and the material powder, which takes into account the thermal insulation and energy conservation demands and the heat dissipation demand of the coil in the process of powder heat treatment.

[28] 13. The magnet yoke is distributed outside the magnetic induction coil, which not only defines the position of the induction coil, but also restricts the outward diffusion of induction magnetic leakage, improves the efficiency of induction heating, and serves as a magnetic shield to ensure the environmental safety of the device.

[29] 14. The non-metal and non-thermocouple temperature sensors are used to avoid the impact of electromagnetic induction on the temperature measurement, and can achieve a fine temperature control in combination with the power supply with adjustable power.

[30] 15. The wear-resistant layer is made of non-magnetic and non-conductive materials to avoid electromagnetic shielding for metal milling balls, so that the induction heating is concentrated in the cylinder body and is directly transmitted to the target material through heat transfer, which is efficient and energy-saving.

[31] 16. Gas pipelines are added, which can use high-pressure gas to blow and vertically stir the materials, thus reducing the situation that the materials are compacted by milling balls to form a material layer on the cylinder wall due to a centrifugal force, thereby improving the milling efficiency.

[32] 17. The milled powder is taken out of the cylinder body by the gas from the gas outlet channel in time to avoid over-milling. While saving energy, the particle size distribution of the powder products is narrower, the uniformity of the powder particles is better, and the product quality is improved.

[33] 18. The screen at the gas outlet is replaceable. It is more convenient and accurate to control the fineness of the product by using the screen with different mesh sizes than the traditional method of controlling the particle size of the product by milling time according to experience. The particle size of the product is less affected by fluctuation of each batch of feeding amount and raw materials, and the quality is more stable.

BRIEF DESCRIPTION OF THE DRAWINGS

[34] FIG. 1 is a schematic structural diagram of a high-temperature planetary ball-milling device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[35] Hereinafter, specific embodiments of the present disclosure will be explained with reference to the accompanying drawings.

[36] As shown in FIG. 1, the present disclosure provides a high-temperature planetary ball-milling device, which includes a tray 1, a plurality of ball milling units 2, a base 3, a main shaft 4 and a gas inlet and outlet control system.

[37] The tray 1 is horizontally provided and is rotatable in a horizontal plane around its center.

[38] Each ball milling unit 2 includes an external frame 21, an inner cylinder 22, a planetary gear 23 and a plurality of metal milling balls 24.

[39] The external frame 21 includes a frame body 211, which is provided on the tray 1 and is rotatable relative to the tray 1. The frame bodies 211 of the plurality of ball milling units 2 are uniformly distributed around a center of the tray 1.

[40] The planetary gear 23 is fixedly sleeved on the frame body 211, the planetary gear 23 rotates, a rotation direction of the planetary gear is opposite to that of the tray 1, and the frame body 211 rotates along with the planetary gear 23 in a direction opposite to a rotating direction of the tray 1 while revolving along with the tray 1.

[41] Specifically, the center of the bottom of the frame body 211 is provided with a frame rotating shaft 2111 protruding downward. The tray 1 is provided with a plurality of rotating shaft holes penetrating through the tray, and the number of the rotating shaft holes is equal to the number of ball milling units 2, and the rotating shaft holes and the ball milling units correspond to each other. The frame rotating shaft 2111 of the frame body 211 of each ball milling unit 2 passes through a corresponding rotating shaft hole and is relatively rotatable in the rotating shaft hole. The planetary gear 23 is located below the tray 1 and fixedly sleeved on a part of the frame rotating shaft 2111 protruding downward out of the tray 1.

[42] The main shaft 4 is vertically provided on a bottom surface in the base 3 and is capable of being driven to rotate by a driving device. The center of the tray 1 is fixedly sleeved on the main shaft 4 and rotates along with the main shaft 4. In a preferred embodiment, the side wall of the base can extend up to a height beyond the tray, and a bearing is provided between the tray and the side wall of the base, so that the rotation of the tray is more stable.

[43] A circle of internal gears 5 are provided in the side wall of the base 3, which are located on the outer side of the planetary gears 23 of the plurality of ball milling units 2 and are engaged with the planetary gears 23. When the tray 1 drives the planetary gear 23 to revolve, the planetary gear 23 rotates under the action of the internal gears 5.

[44] In this embodiment, the planetary gear 23 is provided at the bottom of the frame body 211, and drives the frame body 211 to rotate by the frame rotating shaft 2111 at the bottom of the frame body. The planetary gear 23 can also be provided at a top of the frame body 211, and the rotation of the frame body can be realized by providing the frame rotating shaft 2111 at the top of the frame body 211, or the planetary gear 23 can be directly fixedly sleeved outside the frame body 211 to drive it to rotate.

[45] The inner cylinder 22 includes a cylinder body 221 and a cylinder cover 222.

[46] The cylinder body 221 is vertically fixed in the frame body 211 and rotates along with the frame body 211. A thermal insulation layer 2211 is coated on the inner cylinder wall of the cylinder body 221 (including the side cylinder wall and the bottom cylinder wall), and a wear-resistant layer 2212 is coated on the thermal insulation layer 2211. The thermal insulation layer refers to a layer of thermal insulation structure made of thermal insulation materials. The materials of the thermal insulation layer are all non-magnetic and non-conductive materials to avoid electromagnetic shielding. In some embodiments, in applications with lower heating temperature, the thermal insulation layer is made of organic foaming materials. Under requirements of high temperature (higher than 200°C), the thermal insulation layer is made of porous ceramic refractory material. The wear-resistant layer 2212 refers to a layer of wear-resistant structure made of wear-resistant materials. The wear-resistant layer is made of non-magnetic and non-conductive materials to avoid electromagnetic shielding, and is preferably made of dense wear-resistant ceramics, such as zirconia or tungsten carbide.

[47] A magnet yoke coil layer is further provided in the cylinder body 221 and is embedded in the thermal insulation layer 221 on an inner side wall of the cylinder body.

The magnet yoke coil layer includes a magnet yoke 2213 and a coil 2214, and the coil 2214 is embedded in an inner side of the magnet yoke 2213. Specifically, the magnet yoke 1s a structure formed by stacking strip-shaped sheets made of soft magnetic materials with relatively high magnetic permeability, which can effectively control magnetic leakage, shield the magnetic field and ensure environmental safety while playing a supporting role for the coil. The coil is formed by winding along a bracket built inside the magnet yoke.

[48] The coil 2214 is connected with a high-frequency power supply, i.e. powered by a high-frequency AC power supply. The frequency range is 1000 to 100000 Hz, and the power of the power supply is adjustable. The high-frequency alternating magnetic field generated by the high-frequency power supply has a skin effect, so that the electromagnetic induction heating is concentrated on the surface of the milling ball,

which is beneficial to heat transfer to the materials, thereby having a direct heating and a high efficiency. Specifically, a carbon brush 25 is provided in the rotating shaft hole.

The coil 2214 is connected with the frame body 211 through a wire, and then is rotatably connected with an external high-frequency AC power source through the carbon brush 25.

[49] The above-mentioned multilayer structure in this embodiment can be added (for example, other functional layers are added), combined (for example, ceramic is used as wear-resistant and thermal insulation layer), or split (for example, the coil and the magnet yoke are provided separately, and the magnet yoke is located on the outer side of the coil) based on the actual application, or the order of the multiplayer structure can be adjusted. However, the following should be defined: the wear-resistant layer 1s located at the innermost side; the coil structure is located outside the thermal insulation layer or embedded in the outer side of the thermal insulation layer, which not only realizes system thermal insulation, but also gives consideration to coil heat dissipation; the coil 1s located inside the magnet yoke or embedded in the inner side of the magnet yoke to control the magnetic leakage and ensure the environmental safety of the system. For example, the magnet yoke coil layer can also completely cover the outer side of the thermal insulation layer. [S0] The cylinder cover 222 covers a top opening of the cylinder body 221 in a sealed manner. The cylinder cover is made of thermal insulation material, which prevents heat loss in the production and heating process. Furthermore, a closed space required for production is formed between the cylinder body and the cylinder cover. A plurality of temperature-resistant sealing rings 223 are provided between the cylinder cover 222 and the top opening of the cylinder body 221 to ensure the gas tightness of the system.

[51] The external frame 21 further includes a fastening bracket 212 and a fastening screw 213. The fastening bracket 212 is detachably fixed on an upper end of the frame body 211. The fastening screw 213 passes through the fastening bracket 212 with a lower end abutting against the cylinder cover 222. The fastening screw 213 is threadedly connected with the fastening bracket 212. The fastening screw 213 is screwed, and the fastening screw 213 abuts against the cylinder cover 222 downwards to seal the inner cylinder 22.

[52] The plurality of metal milling balls 24 are provided in the cylinder body 221.

The material of the metal milling ball is wear-resistant high chromium steel or nickel-based high-temperature alloy, which is wear-resistant high chromium steel at the heating temperature below 300°C and is nickel-based high-temperature alloy at the heating temperature above 300°C. [S3] The material is put into the cylinder body 221. When the cylinder body 221 rotates, the metal milling ball 24 grinds the material in the rolling cylinder body 221.

At the same time, the coil 2214 is energized with high-frequency alternating current to generate an alternating magnetic field inside the cylinder body 221, so that the surface of the metal milling ball 24 generates induced eddy current heating to heat the material.

[54] In a preferred embodiment, the device further includes a non-metallic and non-thermocouple temperature sensor, which is provided in the cylinder body to measure a temperature of the material within the cylinder body. For example, a ceramic temperature sensor can be selected and integrated on the wear-resistant layer, or an infrared sensor can be selected to set an observation window on the cylinder cover. The temperature of the material in the heating ball milling system can be subjected to infrared measurement through the observation window. By measuring the temperature in real time and controlling the power of the high-frequency power supply connected to the coil by a microcomputer, the temperature can be accurately controlled.

[55] The gas inlet and outlet control system is communicated with the inner cylinder 22 of each ball milling unit 2 to control the gas to entering and leaving the inner cylinder 22. The gas outlet part of the gas inlet and outlet control system has a function of discharging control. [S6] The ball milling unit 2 is provided with a gas inlet channel 611 running through the bottom of the external frame 21 and the inner cylinder 22 and a gas outlet channel 621 running through the top of the external frame 21 and the inner cylinder 22.

The gas enters the inner cylinder 22 through the gas inlet channel 611 and then is discharged through the gas outlet channel 621. Specifically, the gas inlet channel 611 runs through the frame rotating shaft 2111 and the bottom of the cylinder body 221 of the inner cylinder 22. The gas outlet channel 621 runs through the cylinder cover 222 of the inn cylinder 22 and the fastening screw 213. Specifically, the gas inlet channel and the gas outlet channel can be formed by aligning and connecting a plurality of through holes, and seals are provided among the plurality of through holes to ensure overall gas tightness; alternatively, the gas inlet channel and the gas outlet channel can also be realized as an integral pipeline that runs through the above components.

[57] The gas inlet and outlet control system includes a plurality of spherical cap-shaped cover plates 63. Each spherical cap-shaped cover plate is provided in the inner cylinder 22 of the corresponding ball milling unit 2, and cover a port of the gas inlet channel 611. The spherical cap-shaped cover plate 63 is connected with the bottom surface of the inner cylinder 22 through an elastic member. The elastic member may be a spring. [S8] Opening and closing of the spherical cap-shaped cover plate 63 is controlled according to a relative pressure between the gas inlet pressure and the gas pressure in the cylinder body 221. When the gas inlet pressure is greater than the pressure in the cylinder body 221, the spherical cap-shaped cover plate 63 is pushed to open by the gas inlet pressure. The gas enters the cylinder body 221 through a circular slit formed between an edge of the spherical cap-shaped cover plate 63 and the bottom of the cylinder body 221, and passes through the material layer from bottom to top, so as to form a protective atmosphere in the cylinder body 221 or react with the material. When the gas inlet pressure is less than the pressure in the cylinder body 221, the spherical cap-shaped cover plate 63 is automatically closed by a restoring force of the elastic member, which prevents the material from entering the gas inlet channel 611 and prevents the gas inlet channel 611 from being blocked.

[59] A replaceable screen 64 is provided at the port of the gas outlet channel 621 on the cylinder cover 222. In the production process, the gas inlet pressure is intermittently increased, so that the gas flow carries powder materials to impact the screen. The powder materials which are milled and qualified and reach a target fineness are blown out via the gas outlet channel along with the gas through the screen.

The powder particles that are too large and do not reach the target fineness cannot pass through the screen, but fall back due to gravity and are continuously milled. The screen is replaceable, and a mesh size of the screen can be selected according to the target fineness of the product.

[60] The gas inlet and outlet control system further includes a gas inlet main channel 612 and a plurality of gas inlet branch pipelines 613. The gas inlet main channel 612 is provided at the bottom of the main shaft 4. The number of gas inlet branch pipelines 613 is equivalent to the number of ball milling units 2, and the gas inlet branch pipelines and the ball milling units correspond to each other. One end of the gas inlet branch pipeline 613 is communicated with the gas inlet main channel 612, and the other end thereof is communicated with the gas inlet channel 611 of the corresponding ball milling unit 2 through a gastight bearing 65. The gas inlet and outlet control system includes a gas outlet main channel 622 and a plurality of gas outlet branch pipelines 623. The gas outlet main channel 622 is provided at the top of the main shaft 4. The number of the gas outlet branch pipelines 623 is equivalent to the number of ball milling units 2, and the gas outlet branch pipelines and the ball milling units correspond to each other. One end of the gas outlet branch pipeline 623 is communicated with the gas outlet channel, and the other end thereof 1s communicated with the gas outlet channel 621 of the corresponding ball milling unit 2 through a gastight bearing 65. The gastight bearing maintains gas tightness while ensuring rotary connection.

[61] The gas enters the device through the gas inlet main channel 612 and is discharged through the gas outlet main channel 622.

[62] The gas inlet branch pipeline 613 and the gas outlet branch pipeline 623 are both provided with valves 66. Closing the valve on the gas inlet branch pipeline 613 can reduce the gas inlet pressure, and closing the valve on the gas outlet branch pipeline 623 can cause the gas pressure in the cylinder body 221 to rise.

[63] In operation, the materials A and a plurality of metal milling balls 24 are placed in the cylinder body 221 of the inner cylinder 22 in advance. The external motor drives the main shaft 4 and the tray 1 connected to the main shaft to rotate.

While following the revolution of the tray 1 around the main shaft 4, the inner cylinder 21 and the external frame 21 rotate at a high speed due to relative motion between the planetary gear 23 and the internal gear 5, which drives the materials A and the metal milling balls 24 to move and grind the materials A. At the same time, the coil 2214 is energized with high-frequency alternating current to generate an alternating magnetic field inside the cylinder body, so that the surfaces of the metal milling balls 24 generate induced eddy current heating to heat the materials. At the same time, the gas enters the cylinder body 221 through the gas inlet and outlet control system to control the atmosphere in the cylinder body 221. According to the production demands, the reactive gas can be introduced to realize the high-temperature reaction between the gas and the materials. The gas inlet branch pipeline 613 and the gas outlet branch pipeline 623 are connected with the ports of the gas inlet channel 611 and the gas outlet channel 621 on the external frame 21 through gastight bearings, and only revolve with the main shaft 4, but do not participate in the rotation. The gas inlet pressure intermittently increases, so that the milled powder is carried by the gas through the screen and is taken out of the cylinder body through the gas outlet, thus avoiding excessive milling and improving uniformity of the particle sizes of the products. After the milled powder carried by the gas is blown out, the milled power is subjected to gas-solid separation, the solid is the target product. The gas can be reused after being pressurized. If it is reactive gas, a gas concentration sensor should be provided at the front end of the booster, so as to prevent a low concentration of the reactive gas from affecting the product quality.

Claims

Conclusions

A planetary high temperature ball mill device, comprising: a carrier and a plurality of ball mill units; wherein the carrier is provided horizontally and is rotatable in a horizontal plane about a center thereof; each ball mill unit comprising an outer frame, an inner cylinder, a planetary gear and a plurality of metal grinding balls; wherein the outer frame comprises a frame body, the frame body being provided on the carrier and rotatable relative to the carrier; wherein frame bodies of the plurality of grinding ball units are uniformly distributed about the center of the carrier; wherein the planetary gear is fixedly cased on the frame body, the planetary gear rotates, and wherein a direction of rotation of the planetary gear is opposite to that of the carrier, and wherein the frame body rotates together with the planetary gear in a first direction while in conjunction with the carrier turns in a second direction opposite to the first direction; wherein the inner cylinder comprises a cylinder body mounted vertically in the frame body and rotates together with the frame body; wherein a thermal insulation layer is disposed on an inner cylinder wall of the cylinder body, a wear-resistant layer is disposed on an inner side of the thermal insulation layer, wherein a magnet yoke coil layer is further provided in the cylinder body and located on an outer side of the thermal insulation layer or embedded in an outer side of the thermal insulation layer; wherein the magnet yoke coil layer comprises a magnet yoke and a coil, the coil being contained within the magnet yoke or embedded in an interior of the magnet yoke; the coil being connected to a high frequency power supply; the plurality of metal grinding balls being provided in the cylinder body; wherein materials are placed in the cylinder body, and the metal grinding balls crush the materials in the rolling cylinder body, and the coil is energized with a high frequency alternating current to generate an alternating magnetic field in the cylinder body such that surfaces of the metal grinding balls are heated due to generated eddy current, in order to heat the materials.

The planetary high temperature ball mill apparatus according to claim 1, wherein the magnetic yoke coil layer is embedded in a portion of the thermal insulation layer on a cylinder side wall of the cylinder body; wherein the coil is embedded in the inside of the magnetic yoke.

The planetary high temperature ball mill apparatus according to claim 1, wherein a center of a bottom side of the frame body has a frame rotational axis protruding downward; wherein the carrier is provided with a plurality of pivot holes extending through the carrier, and wherein a number of the pivot holes is equal to a number of the ball mill units, and wherein the pivot holes and the ball mill units are arranged one-to-one - be one agreement; wherein the frame pivot axis of the frame body of the ball mill unit passes through a corresponding pivot axis hole and is relatively rotatable in the corresponding pivot axis hole; wherein the planetary gear is located below the carrier and is fixedly sheathed on a portion of the frame pivot shaft extending downwardly from the carrier.

The planetary high temperature ball mill apparatus according to claim 3, further comprising a base and a main shaft; wherein the main shaft is vertically provided on a lower surface of the base and is capable of being driven by a driving device; wherein the center of the carrier is fixedly sheathed on the main shaft and rotates together with the main shaft.

The planetary high temperature ball mill apparatus according to claim 4, wherein a circle of internal teeth is provided on an inner side wall of the base, located on outer sides of planetary gears of the plurality of ball mill units and meshed with the planetary gears; wherein if the carrier drives the planet gears to rotate, the planet gears rotate under the action of the internal gears.

The planetary high temperature ball mill apparatus according to claim 5, further comprising a gas inlet and outlet control system communicating with the inner cylinder of the ball mill unit and directing gas to enter or exit the inner cylinder.

The planetary high temperature ball mill apparatus according to claim 6, wherein the inner cylinder further comprises a cylinder cover covering an upper opening of the cylinder body in a sealed manner; the ball mill unit having a gas inlet channel passing through bottoms of the outer frame and inner cylinder and a gas outlet channel passing through tops of the outer frame and inner cylinder, the gas entering the inner cylinder through the gas inlet channel and then discharged through the gas outlet channel; wherein the gas inlet and outlet control system comprises a plurality of spherical, cap-shaped cover plates provided in one-to-one correspondence in inner cylinders of the ball mill units; wherein a port of the gas inlet channel is covered with a corresponding spherical cap-shaped cover plate, and each spherical cap-shaped cover plate is connected to a lower surface of a corresponding inner cylinder via an elastic member; wherein, if a gas inlet pressure is greater than a pressure in the cylinder body, the spherical cap-shaped cover plate is pushed by the gas inlet pressure to open, and wherein, if the gas inlet pressure is less than the pressure in the cylinder body, the spherical cap-shaped cover plate is automatically closed by a restoring force of the elastic element.

The planetary high temperature ball mill apparatus according to claim 7, wherein the gas inlet and outlet control system further comprises a gas inlet main channel and a plurality of gas inlet branch pipelines, the gas inlet main channel being provided on an underside of the main shaft, a number of the gas inlet branch pipelines being equivalent to 1s to the number of the ball mill units , and wherein the gas inlet branch pipelines and the ball mill units are in one-to-one correspondence, and where one end of each gas inlet branch pipeline is connected to the main gas inlet channel, and another end thereof is connected to a gas inlet channel of a corresponding ball mill unit via a first gas-tight bearing; wherein the gas inlet and outlet control system further comprises a gas outlet main channel and a plurality of gas outlet branch pipelines, the gas outlet main channel being provided on an upper side of the main shaft, a number of the gas outlet branch pipelines being equivalent to the number of the ball mill units, and wherein the gas outlet branch pipelines and the ball mill units are in one-to-one correspondence, where one end of each gas outlet branch pipeline is connected to the main gas outlet channel, and another end thereof is connected to a gas outlet channel of a corresponding ball mill unit through a second gas-tight bearing; wherein the gas enters the device through the gas inlet main channel and is discharged through the gas outlet main channel.

The planetary high temperature ball mill apparatus according to claim 8, wherein both the gas inlet branch pipeline and the gas outlet branch pipeline are provided with valves.

The planetary high temperature ball mill apparatus according to claim 7, wherein the outer frame further comprises a fixing bracket and a fixing screw, the fixing bracket being releasably mounted on an upper end of the frame body, the fixing screw passing through the fixing bracket, a lower end thereof pressing against the cylinder cover, wherein the locking screw is threadedly connected to the locking bracket, the locking screw being screwed down to press against the cylinder cover to seal the inner cylinder.