Fine-grained graphite batch spheroidizing equipment

Abstract

The present invention relates to a spheroidizing device for fine-particle graphite batches, comprising a housing having a spheroidizing cavity; a grinding disc structure and a grading cage-type impeller are arranged in the spheroidizing cavity, and the grading cage-type impeller includes a rotating shaft, a top frame, a chassis and a diversion fence; the rotating shaft is fixedly connected to the chassis and its lower end extends out of the chassis and is connected with an auxiliary blade assembly and a flow guide member, and the auxiliary blade assembly includes a plurality of auxiliary blades and can make the air flow form a vortex; an annular grading and flow guiding assembly is arranged on the outer periphery of the grading cage-type impeller and close to the inner wall of the spheroidizing cavity, and the grading and flow guiding assembly includes a plurality of flow guiding blades arranged at circumferential intervals, and the plate surface of each flow guiding blade is inclined relative to the corresponding radial direction in the spheroidizing cavity and the inclination directions are the same. The present invention effectively solves the problems of complex process, high energy consumption, low production efficiency and low product quality in the existing spheroidizing process of fine-particle graphite in view of the characteristics of fine-particle graphite.

Description

Technical Field

[0001] The present invention relates to the technical field of deep processing of natural graphite, and particularly to a batch spheroidizing device for fine-particle-size graphite. Background Art

[0002] The raw material for natural graphite spheroidization is flake graphite. Due to its lamellar structure, multiple spheroidizing devices are required for combined treatment to spheroidize it, resulting in a large number of machines involved in the spheroidization process, high energy consumption, and high costs. Therefore, this device adopts a batch spheroidization method for one device to reduce the number of machines.

[0003] Currently, the particle size of spherical graphite products shows a multi-level development trend. There are certain differences in the ball-forming mechanisms between coarse-particle-size and fine-particle-size natural graphite. This is because fine-particle-size natural graphite and coarse-particle-size natural graphite have different volume forces, so they have different movement trajectories and residence times in the spheroidization chamber housing. During the crushing process, different from coarse-particle-size graphite, fine-particle-size graphite has a low efficiency of plastic deformation; during the classification process, the differences between fine-particle-size natural graphite and coarse-particle-size natural graphite are also particularly obvious. Due to the different centrifugal forces on fine-particle-size natural graphite and coarse-particle-size natural graphite, fine-particle-size natural graphite has a smaller centrifugal force at the same rotation radius and has a greater probability of entering the classification wheel rotor under the action of negative pressure and being collected as tailings through the tail powder discharge port. In view of the differences between fine-particle-size natural graphite and coarse-particle-size natural graphite, adjusting the rotation speed of the classification impeller and the air volume parameters of the fan may improve the situation. If only relying on increasing the rotation speed of the classification impeller to reduce the particle size of the crushed particles, a higher classification speed will inevitably cause an increase in the flow path resistance of the impeller, blockage of the classification impeller, resulting in an increase in the output power of the fan, and may seriously damage the equipment. Therefore, it is not possible to simply adjust the parameters on the original spheroidizing device. It is necessary to design a dedicated high-efficiency batch spheroidizing device for fine-particle-size natural graphite to solve the above technical problems.

[0004] The "Background Art" paragraph is only used to help understand the content of the present invention. Therefore, the content recorded in the "Background Art" paragraph may contain some common knowledge that is not known to those skilled in the art. The content recorded in the "Background Art" paragraph does not represent the content or the problems to be solved by one or more embodiments of the present invention, which have been known or recognized by those skilled in the art before the filing of the present invention application. Summary of the Invention

[0005] The purpose of the present invention is to develop a batch spheroidizing device for fine-particle-size graphite, which can effectively solve the problems of complex process, high energy consumption, low production efficiency, and low product quality during the spheroidization process of fine-particle-size graphite.

[0006] The object of the present invention is achieved as follows. A fine-particle-size graphite batch spheroidizing device includes a housing having a spheroidizing cavity; a rotatable grinding disc structure and a rotatable grading cage impeller are respectively provided at the bottom and top in the spheroidizing cavity. The grading cage impeller includes a rotating shaft, a top frame and a chassis spaced up and down, and a diversion fence connected between the top frame and the chassis; the rotating shaft is fixedly connected to the chassis, and its lower end extends out of the chassis and is connected with an auxiliary blade assembly and a flow guide member arranged up and down. The auxiliary blade assembly includes a plurality of auxiliary blades circumferentially spaced on the rotating shaft and can make the air flow form a vortex; an annular grading and diversion assembly is provided at a position on the outer periphery of the grading cage impeller and close to the inner wall of the spheroidizing cavity. The grading and diversion assembly includes a plurality of diversion blades circumferentially spaced, and the plate surface of each diversion blade is inclined relative to the corresponding radial direction in the spheroidizing cavity.

[0007] In a preferred embodiment of the present invention, the flow guide member adopts a streamlined design and is a water droplet-shaped structure with a rounded lower end and a gradually narrowing upper end.

[0008] In a preferred embodiment of the present invention, the diversion blade is a rectangular plate body with a vertically arranged plate surface, and the inclination angle range of the plate surface of the diversion blade relative to the corresponding radial direction in the spheroidizing cavity is 66 - 75°.

[0009] In a preferred embodiment of the present invention, the diversion fence includes a plurality of diversion rods circumferentially and evenly spaced. The two ends of each diversion rod are respectively connected to the outer edge positions of the top frame and the chassis; the grading cage impeller is an inverted conical structure with an outer diameter gradually increasing from bottom to top.

[0010] In a preferred embodiment of the present invention, the rotational speed of the grading cage impeller is less than or equal to 3000 r / min.

[0011] In a preferred embodiment of the present invention, the cross-section of the housing is circular. The inner wall of the housing includes a first cylindrical surface, a conical surface with a diameter increasing from bottom to top, and a second cylindrical surface connected in sequence from bottom to top. The grinding disc structure is arranged opposite to the first cylindrical surface, and the grading cage impeller is arranged opposite to the second cylindrical surface.

[0012] In a preferred embodiment of the present invention, a feed pipe and a finished product discharge pipe are connectably and disconnectably connected to a position on the side of the housing corresponding to the area between the grading cage impeller and the grinding disc structure. An air outlet is provided at the top of the housing opposite to the grading cage impeller, and a tail powder discharge pipe is connectably and disconnectably connected thereto; a discharge valve is provided on the finished product discharge pipe, and the discharge valve can be automatically opened after a preset time for material spheroidization to complete the discharge; an induced draft fan is also connected to the tail powder discharge pipe, and an air supply port communicating with the spheroidizing cavity is further provided at the bottom of the housing.

[0013] In a preferred embodiment of the present invention, a hopper is further connected to the end of the feed pipe away from the housing. The hopper is connected to the first end of the screw conveyor, and the second end of the screw conveyor is connected to a silo. The lower part of the silo is a conical body with a gradually decreasing inner diameter downward, and air flow assisting discs are provided on the inner wall of the conical body.

[0014] In a preferred embodiment of the present invention, the grinding disc structure includes at least two layers of graphite nodulizing discs arranged at intervals up and down, and a plurality of grinding blocks are circumferentially arranged at intervals on the top surface of the graphite nodulizing disc; a ring-shaped gear is provided on the inner wall of the nodulizing cavity at a position facing the grinding disc structure.

[0015] In a preferred embodiment of the present invention, the cross-section of the grinding block is a parallelogram, and a plurality of annular grooves are arranged at intervals from top to bottom on the outer side wall of the grinding block. A part of the grinding block extends out of the outer peripheral edge of the graphite nodulizing disc and there is a gap between the grinding block and the gear ring.

[0016] In a preferred embodiment of the present invention, an impeller driving device is further provided on the top of the housing. The impeller driving device can be connected to the rotating shaft and is used to drive the classification cage impeller to rotate; a grinding disc driving device is provided at the bottom of the housing. The grinding disc driving device can be connected to the grinding disc structure and is used to drive the grinding disc structure to rotate.

[0017] As described above, the fine-particle-size graphite batch spheroidizing equipment of the present invention can perform batch spheroidizing treatment on fine-particle-size graphite with only one piece of equipment, making its shape more spherical, simplifying the process and reducing the cost. Compared with the existing equipment that does not have a specific equipment distinction for spheroidizing fine-particle-size and coarse-particle-size graphite, this equipment targets the differences between fine-particle-size graphite and coarse-particle-size graphite. During the classification process, a flow guide is set to guide the rising air flow, reducing the air flow impact; a classification cage impeller is set, and by adjusting its rotation speed and the gap of the diversion fence, the inhalation of fine-particle-size graphite as tail powder can be reduced; auxiliary blades are set, which can generate eddy currents in the rising air flow as they rotate at high speed with the classification cage impeller, guiding the flow direction of the material in the rising process to the periphery, better entering the annular area, and dispersing the agglomerated tail powder or finer-particle-size graphite and the tail powder or finer-particle-size graphite attached to the fine-particle-size graphite; a flow guide blade is set, which can change the velocity field distribution in the annular area and disperse the agglomerated tail powder or finer-particle-size graphite and the tail powder or finer-particle-size graphite attached to the fine-particle-size graphite. Furthermore, through the cooperation of the classification cage impeller, the flow guide, the auxiliary blades and the flow guide blades, the classification of the material during the spheroidizing treatment of the material in the spheroidizing cavity can be made more precise; the situation where fine-particle-size graphite is misclassified as tail powder, thus reducing the ball forming rate, can be effectively avoided; the agglomeration of tail powder or finer-particle-size graphite being regarded as fine-particle-size graphite and being incorporated into the fine-particle-size graphite finished product can also be effectively avoided, and the situation where tail powder or finer-particle-size graphite is attached to the fine-particle-size graphite and then enters the spheroidizing area again for curling and compaction and is incorporated into the fine-particle-size finished product can be avoided, thus causing problems such as low tapped density, large specific surface area, irregular morphology, low finished product qualification rate and inability to meet the product specification requirements of the fine-particle-size spherical graphite finished product. The qualified ball forming rate of the fine-particle-size graphite product is effectively improved, and the production efficiency and product quality are improved. Brief Description of the Drawings

[0018] The following drawings are only intended to illustrate and explain the present invention and do not limit the scope of the present invention. Among them:

[0019] Figure 1 It is a schematic structural diagram of the fine-particle-size graphite batch spheroidizing equipment provided by the present invention.

[0020] Figure 2 It is a schematic structural diagram of the classification cage impeller provided by the present invention.

[0021] Figure 3 It is a schematic structure of the classification cage impeller and the flow guide blade provided by the present invention Figure 1 .

[0022] Figure 4 It is a schematic structure of the classification cage impeller and the flow guide blade provided by the present invention Figure 2 .

[0023] Figure 5a Top view of the graphite nodulizing disc and one of the grinding blocks provided by the present invention.

[0024] Figure 5b Three-dimensional view of the grinding block provided by the present invention.

[0025] Figure 5c Schematic diagram of the cooperation of the graphite nodulizing disc, the grinding block and the gear ring provided by the present invention.

[0026] Figure 6 Schematic diagram of the structure of the spherical graphite batch nodulizing equipment connected with an induced draft fan, a tail powder dust collector and a finished product dust collector provided by the present invention.

[0027] Figure 7 Schematic diagram of the structure of the silo provided by the present invention.

[0028] Figure 8 SEM image I of the raw material used in the experiment provided by the present invention, Figure 8 with a scale bar of 50μm.

[0029] Figure 9 SEM image II of the raw material used in the experiment provided by the present invention, Figure 9 with a scale bar of 4μm.

[0030] Figure 10 SEM image I of the product obtained after the raw material provided by the present invention is tested according to the test parameter a, Figure 10 with a scale bar of 50μm.

[0031] Figure 11 SEM image II of the product obtained after the raw material provided by the present invention is tested according to the test parameter a, Figure 11 with a scale bar of 5μm.

[0032] Figure 12 SEM image I of the product obtained after the raw material provided by the present invention is tested according to the test parameter b, Figure 12 with a scale bar of 50μm.

[0033] Figure 13 SEM image II of the product obtained after the raw material provided by the present invention is tested according to the test parameter b, Figure 13 with a scale bar of 5μm.

[0034] Explanation of the reference numerals in the drawings:

[0035] 1. Housing; 11. Spheroidizing cavity; 121. First cylindrical surface; 122. Conical surface; 123. Second cylindrical surface; 13. Feed pipe; 131. Hopper; 132. Feed valve; 14. Finished product discharge pipe; 15. Air outlet; 16. Tail powder discharge pipe; 17. Make-up air inlet; 18. Underframe; 19. Gear ring;

[0036] 2. Grinding disc structure; 21. Graphite spheroidizing disc; 22. Grinding block; 221. Annular groove; 222. Edge; 23. Driven pulley; 24. Transmission shaft; 25. Support cylinder; 26. Bearing; 27. Diverting ring;

[0037] 3. Classifying cage impeller; 31. Top frame; 32. Chassis; 33. Diverting fence; 34. Rotating shaft; 35. Auxiliary blade; 36. Flow guide member; 37. Flow guide blade; 38. Impeller driving device; 381. Impeller driving motor;

[0038] 4. Silo; 41. Air disc for assisting flow; 42. Screw conveyor; 5. Vacuum conveyor;

[0039] 6. Induced draft fan; 7. Tail powder dust collector; 8. Finished product dust collector. Specific embodiments

[0040] For a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0041] As Figures 1 to 13 shown, this embodiment provides a fine-particle-size graphite batch spheroidizing device, including a housing 1 having a spheroidizing cavity 11; a rotatable grinding disc structure 2 and a rotatable classifying cage impeller 3 are respectively provided at the bottom and top in the spheroidizing cavity 11. The classifying cage impeller 3 includes a rotating shaft 34, a top frame 31 and a chassis 32 spaced apart vertically, and a diverting fence 33 connected between the top frame 31 and the chassis 32; the rotating shaft 34 is fixedly connected to the chassis 32 and its lower end extends out of the chassis 32 and is connected with an auxiliary blade assembly and a flow guide member 36 arranged vertically. The auxiliary blade assembly includes a plurality of auxiliary blades 35 circumferentially spaced on the rotating shaft 34 and can form a vortex of air flow to disperse the graphite material to the periphery; an annular classifying and flow guiding assembly is provided on the outer periphery of the classifying cage impeller 3 and close to the inner wall of the spheroidizing cavity 11. The classifying and flow guiding assembly includes a plurality of flow guide blades 37 circumferentially spaced, and the plate surface of each flow guide blade 37 is inclined relative to the corresponding radial direction in the spheroidizing cavity 11 and the inclination directions are the same.

[0042] Natural spherical graphite is a spherical graphite product in the shape of a potato-like globular obtained by continuously crushing and spheroidizing and shaping natural flake graphite (lamellar structure) as raw materials. The spherical graphite products can be divided into fine particle size graphite products and coarse particle size graphite products according to the particle size. In the prior art, a relatively large number of devices are required to crush and spheroidize and shape the flake graphite raw materials. The front several devices mainly crush the raw materials, and after classification, fine particle size graphite with irregular morphology is obtained. The rear several devices are connected in series to perform combined spheroidization on the fine particle size graphite so that the fine particle size graphite reaches a certain sphericity and tapped density to obtain fine particle size spherical graphite products, and a relatively large number of devices are required. In this embodiment, one fine particle size graphite batch spheroidization device is used to replace the several devices for spheroidizing and shaping the fine particle size graphite, which can effectively simplify the spheroidization process.

[0043] The whole batch spheroidization device mainly spheroidizes the fine particle size graphite. The raw material is fine particle size graphite with irregular morphology. During production, the raw material is added into the spheroidization cavity 11 for internal circulation and discharged according to a preset time to obtain fine particle size spherical graphite products. Inside the spheroidization cavity 11, it is divided into a shaping area, a transition area and a classification area from bottom to top. The shaping area is arranged opposite to the grinding disc structure 2, and the classification area is arranged opposite to the classification cage impeller 3; after the raw material is shaped by rubbing, compressing, curling, etc. by the grinding disc structure 2 in the shaping area, it flows upward under the action of negative pressure suction and is sucked into the annular area between the classification cage impeller 3 and the inner wall of the spheroidization cavity 11 in the classification area. During this upward process, the flow guiding member 36 can play a role in guiding the air flow, and the use of the auxiliary blades 35 and the flow guiding blades 37 can make the material more dispersed. The graphite material with very fine particle size (generally called tail powder) enters the classification cage impeller 3 and is sucked away and discharged, and the graphite material with larger particle size that is not sucked away falls onto the grinding disc structure 2 for secondary shaping and continuously circulates in the spheroidization cavity 11.

[0044] Thus, the fine-particle-size graphite batch spheroidizing equipment in this embodiment can spheroidize the fine-particle-size graphite with irregular morphology in batches with only one piece of equipment, simplifying the process and reducing costs. Compared with the existing equipment that does not have a special equipment distinction for spheroidizing fine-particle-size and coarse-particle-size graphite, this equipment is specifically designed for spheroidizing fine-particle-size graphite. A flow guide 36 is provided during the classification process to guide the rising air flow, reducing the air flow impact; a classification cage impeller 3 is provided, and by adjusting its rotation speed and the gap of the diversion fence 33, the fine-particle-size graphite being sucked in as tail powder can be reduced; an auxiliary blade 35 is provided, which can generate eddies in the rising air flow as it rotates at a high speed with the classification cage impeller 3, guiding the flow direction of the material in the rising process to the periphery, better entering the annular area, and being able to disperse the agglomerated tail powder or finer-particle-size graphite and the tail powder or finer-particle-size graphite attached to the fine-particle-size graphite; a flow guide blade 37 is provided, which can change the velocity field distribution in the annular area and can disperse the agglomerated tail powder or finer-particle-size graphite and the tail powder or finer-particle-size graphite attached to the fine-particle-size graphite.

[0045] Furthermore, through the cooperation of the classification cage impeller 3, the flow guide 36, the auxiliary blade 35 and the flow guide blade 37, the classification of the material during the spheroidizing process of the spheroidizing cavity 11 can be made more precise; the situation where the fine-particle-size graphite is misclassified as tail powder, thus reducing the ball forming rate, can be effectively avoided; the agglomeration of tail powder or finer-particle-size graphite being regarded as fine-particle-size graphite and being incorporated into the fine-particle-size graphite finished product can also be effectively avoided, and the situation where the tail powder or finer-particle-size graphite adheres to the fine-particle-size graphite and then enters the spheroidizing area again for curling and compaction and is incorporated into the fine-particle-size finished product can be avoided, thus causing problems such as low tapped density, large specific surface area, irregular morphology, low finished product qualification rate and inability to meet product specification requirements of the fine-particle-size spherical graphite finished product, effectively improving the ball forming rate of the qualified fine-particle-size graphite product, and improving production efficiency and product quality.

[0046] It should be noted that the particle size volume distribution of the fine-particle-size spherical graphite product (i.e., the fine-particle-size graphite finished product) mentioned in this embodiment satisfies the median particle size D 50 of 7 - 13 μm, and the particle size volume distribution of the coarse-particle-size spherical graphite product satisfies the median particle size D 50 > 23 μm. The specific particle size division of the fine-particle-size spherical graphite product and the coarse-particle-size spherical graphite product shall be based on the well-known range in the industry. It can be understood that the spherical graphite products mentioned in this article are not completely standard spheres, and can also refer to ellipsoids or quasi-spheres. The graphite in this case mainly refers to natural graphite. The finer-particle-size graphite can also be called fine powder, and its particle size is smaller than that of the fine-particle-size graphite and larger than that of the tail powder.

[0047] Furthermore, the above-mentioned flow guide 36 is preferably of a water droplet type structure with a rounded lower end and a gradually narrowing upper end.

[0048] Reference Figure 2 and Figure 3 The flow guide member 36 is provided at the bottom end of the rotating shaft 34 and is coaxially arranged with the rotating shaft 34. The water droplet-shaped structure has a diameter that first gradually increases and then gradually decreases from top to bottom, and the outer surface has a very gentle smooth transition, and its shape is similar to that of a water droplet. By adopting the water droplet-shaped structure, due to its unique streamline design, it can effectively guide the flow direction of the upward airflow rising from the lower end, reduce eddy currents and resistance, improve the flow efficiency, and make the upward airflow and the material in the upward process flow upward more gently; at the same time, the water droplet-shaped structure can reduce stress concentration, and at the same time, the stress concentration can be further reduced through geometric shapes such as rounding, improving the durability of the water droplet-shaped structure.

[0049] The above-mentioned grading and flow guiding assembly is arranged in the above-mentioned annular area and is close to the inner wall of the spheroidizing cavity 11, and a plurality of flow guiding vanes 37 are evenly spaced along the circumferential direction of the grading and flow guiding assembly. The specific number of the flow guiding vanes 37 is determined according to actual needs. For example, a total of 75 flow guiding vanes 37 are provided in this embodiment.

[0050] Each flow guiding vane 37 is the same size and is a rectangular plate body. The plate surface of each flow guiding vane 37 is arranged vertically. The length direction of each flow guiding vane 37 is arranged along the vertical direction. The width direction of each flow guiding vane 37 is inclined relative to the corresponding radial direction in the grading and flow guiding assembly and has the same inclination direction. Specifically, it is inclined relative to the corresponding radial direction of the spheroidizing cavity 11 in the rotation direction of the grading cage impeller 3 from the inside of the spheroidizing cavity 11 to the outside; for example, in this embodiment, the grading cage impeller 3 rotates clockwise, and the width direction of each flow guiding vane 37 is inclined from the inside of the spheroidizing cavity 11 to the outside in the cross section of the spheroidizing cavity 11 in the clockwise direction relative to the corresponding radial direction and is inclined at a preset angle.

[0051] If the preset inclination angle is too small, it will cause the movement speed of the material in the grading area to decrease, and at the same time, it will block the movement of the material, thereby reducing the grading accuracy; if the preset inclination angle is too large, it will destroy the stability of the flow field in the grading area, unable to achieve the flow guiding effect, and is not conducive to the grading of the material. Therefore, in this embodiment, the inclination angle range of the plate surface of the flow guiding vane 37 relative to the corresponding radial direction in the spheroidizing cavity 11 is preferably 66-75°. Under this parameter, it is more conducive to the dispersion of the material, more conducive to the fine grading of the material, more conducive to improving the ball forming rate of qualified fine particle size spherical graphite products, and improving the product quality.

[0052] The internal flow state of the spheroidizing cavity 11 belongs to moderately intense turbulence. Due to the inherent dissipative characteristics of turbulence, in the turbulent flow field of the classification zone, the largest-scale eddies will dissipate energy into smaller and smaller eddies until, at the smallest scale, the energy is dissipated as heat into the fluid. Installing the guide vane 37 results in less turbulent dissipation compared to not installing the guide vane 37, and a smaller turbulent dissipation rate is more conducive to the stability of the flow field and reducing the energy consumption during the production of fine-grained natural graphite, thereby improving the classification efficiency.

[0053] Furthermore, referring to Figure 2 , the flow splitting fence 33 includes multiple flow splitting rods arranged at circumferentially uniform intervals. The two ends of the flow splitting rods are respectively connected to the outer edge positions of the top frame 31 and the chassis 32; the classified cage impeller 3 has an inverted conical structure with an outer diameter gradually increasing from bottom to top.

[0054] The chassis 32 is a disc structure. The top frame 31 can be a hollow circular frame or a ring structure. The outer diameter of the top frame 31 is greater than that of the chassis 32. The entire classified cage impeller 3 forms an inverted conical structure with a larger top and a smaller bottom. The flow splitting rods can be made of wear-resistant steel rods, and the specific number can be determined according to needs. For example, a total of 70 flow splitting rods are provided in this embodiment. The flow splitting rods can be cylindrical rods or, as shown in Figure 2 , relatively thin rectangular rods.

[0055] In this embodiment, for the spheroidization of fine-grained graphite, a guide member 36, auxiliary vanes 35, and guide vanes 37 are specifically provided in the equipment, which can make the material more dispersed and is more conducive to improving the classification effect of the material. Therefore, the rotational speed of the classified cage impeller 3 does not need to be so high. In this embodiment, the rotational speed of the classified cage impeller 3 is less than or equal to 3000 r / min, and is further preferably 1500 - 2500 r / min. At this relatively low rotational speed, fine-grained graphite can be prevented from being sucked away as tail powder, improving the yield.

[0056] Furthermore, referring to Figure 1 , the cross-section of the housing 1 is circular. The inner wall of the housing 1 includes a first cylindrical surface 121, a conical surface 122 with a diameter increasing from bottom to top, and a second cylindrical surface 123 connected in sequence from bottom to top. The grinding disc structure 2 is arranged opposite to the first cylindrical surface 121, and the classified cage impeller 3 is arranged opposite to the second cylindrical surface 123.

[0057] The parts of the housing 1 corresponding to the shaping area and the classification area are both cylindrical shells, and the part of the housing 1 corresponding to the transition area is an inverted conical shell. The transition area can play a guiding role for the airflow. The area in the spheroidizing cavity 11 between the classified cage impeller 3 and the grinding disc structure 2 (i.e., the transition area) is a hollow cavity without other components installed, which will not affect the circulation effect of the airflow in the spheroidizing cavity 11. Compared with the case where other components are installed in the transition area, the feeding amount is more and the production capacity is higher.

[0058] Referring to Figure 1 and Figure 6 at the side of the housing 1, the feed pipe 13 and the finished product discharge pipe 14 are connected in a switchable manner at a position corresponding to the area between the grading cage impeller 3 and the grinding disc structure 2. At the top of the housing 1, an air outlet 15 is provided opposite to the grading cage impeller 3, and a tail powder discharge pipe 16 is connected in a switchable manner.

[0059] The feed pipe 13 and the finished product discharge pipe 14 are located on both sides of the transition area of the housing 1. The feed pipe 13 is used to add fine-grained graphite with irregular morphology, and the finished product discharge pipe 14 is used to output the fine-grained graphite finished product. A discharge valve is provided on the finished product discharge pipe 14 and is electrically connected to a control device, which can control the opening and closing of the discharge valve automatically according to the spheroidization time of the fine-grained spherical graphite product preset or required by the system.

[0060] The air outlet 15 is opened at the center position of the top of the housing 1, facing the top frame 31 of the grading cage impeller 3. The first end of the tail powder discharge pipe 16 is provided on the top of the housing 1 and is communicated with the air outlet 15. After the tail powder sucked into the grading cage impeller 3 enters the inner cavity surrounded by the diversion fence 33, it enters the tail powder discharge pipe 16 upward through the air outlet 15 by the top frame 31.

[0061] An induced draft fan 6 is further connected to the tail powder discharge pipe 16, and an air supply port 17 capable of communicating with the spheroidization cavity 11 is further provided at the bottom of the housing 1.

[0062] The induced draft fan 6 is connected to the second end of the tail powder discharge pipe 16. Under the action of the induced draft fan 6, a negative pressure suction can be generated at the air outlet 15, and the particles spheroidized by the grinding disc structure 2 flow upward under the action of the negative pressure suction. The air supply port 17 is located below the grinding disc structure 2, generally provided on the bottom side wall of the housing 1. Two air supply ports 17 can be provided in total. The air supply port 17 has a square cross-section, and a plug board is provided in the air supply port 17, so that the opening and closing size can be adjusted manually. The air supply port 17 can increase the residence time of the fine-grained natural graphite in the annular area and will, to a certain extent, play a role in dispersing the material, so as to reduce the misclassification of the fine-grained spherical graphite product.

[0063] Furthermore, one end of the feed pipe 13 far away from the housing 1 is further connected to a hopper 131. The hopper 131 is connected to the first end of a screw conveyor 42, and the second end of the screw conveyor 42 is connected to a silo 4.

[0064] The axis of the feed pipe 13 is generally arranged to incline downward from the hopper 131 towards the housing 1. A feed valve 132 is installed on the feed pipe 13 to control the on-off here. The screw conveyor 42 is arranged above the hopper 131, and the silo 4 can be a metering silo. When the batch spheroidizing equipment is in the spheroidizing state, the feed valve 132 is in the closed state. After the batch spheroidizing equipment finishes spheroidizing and discharges the finished product, the feed valve 132 is in the open state. Fine-grained graphite with an irregular weight and shape set according to the metering silo enters the spheroidizing cavity 11 through the feed pipe 13 for internal circulation.

[0065] Referring to Figure 7 , the lower part of the silo 4 is a cone with a gradually decreasing inner diameter downward. Flow-aiding air discs 41 are provided on the inner wall of the cone. The flow-aiding air discs 41 can play a role in flow-aiding and arch-breaking, avoiding the phenomenon of wall sticking and arching of fine-grained graphite due to its large surface tension after being stored in the silo 4 for a certain period of time under the action of the surface tension and friction of the material, resulting in blockage of the silo 4.

[0066] Further, referring to Figure 1 , the grinding disc structure 2 includes at least two layers of graphite spheroidizing discs 21 arranged at intervals up and down, and a plurality of grinding blocks 22 are circumferentially spaced on the top surface of the graphite spheroidizing disc 21; an annular gear ring 19 is provided on the inner wall of the spheroidizing cavity 11 at a position opposite to the grinding disc structure 2. Each graphite spheroidizing disc 21 is fixedly connected to the following transmission shaft 24; adopting multiple layers of graphite spheroidizing discs 21 has stronger spheroidizing ability and higher spheroidizing efficiency.

[0067] Preferably, referring to Figure 5a 、 Figure 5b and Figure 5c , the cross-section of the grinding block 22 is a parallelogram, and a plurality of annular grooves 221 are spaced from top to bottom on the outer side wall of the grinding block 22. A part of the grinding block 22 extends out of the outer peripheral edge of the graphite spheroidizing disc 21 and there is a gap between it and the gear ring 19.

[0068] Specifically, the graphite nodulizing disk 21 is a circular disk. The rotation direction of the graphite nodulizing disk 21 is opposite to that of the grading cage impeller 3. The grinding blocks 22 are arranged near the outer peripheral edge of the graphite nodulizing disk 21, and a part of the grinding blocks 22 extends out of the outer peripheral edge of the graphite nodulizing disk 21 and is located in the space between the graphite nodulizing disk 21 and the gear ring 19. Threaded holes are provided in the grinding blocks 22, and they can be fixed to the graphite nodulizing disk 21 through screws. The cross-section of the grinding block 22 in the vertical direction is a parallelogram, which has an acute angle and an obtuse angle. When arranged, it is preferably that one of the acute angles and one of the adjacent obtuse angles of the parallelogram extend out of the outer peripheral edge of the graphite nodulizing disk 21, and the side between the acute angle and the obtuse angle that extends out of the graphite nodulizing disk 21 is arranged to be inclined relative to the corresponding radial direction of the graphite nodulizing disk 21 from the inside of the graphite nodulizing disk 21 outward in the reverse direction of the rotation direction of the graphite nodulizing disk 21, and the other pair of opposite sides of the parallelogram are parallel to the corresponding radial direction of the graphite nodulizing disk 21. For example, referring to Figure 5a , the graphite nodulizing disk 21 rotates counterclockwise. The parallelogram has two acute angles and two obtuse angles. One of the acute angles A and one of the adjacent obtuse angles B extend out of the outer peripheral edge of the graphite nodulizing disk 21. The side L1 between the acute angle A and the obtuse angle B is arranged to be inclined relative to the corresponding radial direction of the graphite nodulizing disk 21 from the inside of the graphite nodulizing disk 21 outward in the clockwise direction, and the two sides L2 adjacent to the side L1 in the parallelogram are parallel to the corresponding radial direction of the graphite nodulizing disk 21. It can make the component velocity of the impact process between the graphite and the grinding block 22 point to the gear ring 19, improving the nodulizing efficiency.

[0069] The annular gap between the grinding block 22 and the gear ring 19 is the main area where the nodulizing process occurs. If the gap between the end of the grinding block 22 and the gear ring 19 is too large, it may cause the flight time of the graphite particles after being impacted to be too long and they cannot be fully impacted and collided. On the contrary, if the number of collisions between the graphite particles and the end of the grinding block 22 and the gear ring 19 increases, it may lead to the fragmentation behavior of the graphite particles; in this equipment, the gap between the two is limited to 3 mm based on the product characteristics of the fine-particle-size spherical graphite (specifically, the minimum gap between the grinding block 22 and the gear ring 19, that is, the gap between the farthest end of the grinding block 22 from the center of the graphite nodulizing disk 21 and the gear ring 19) to be suitable for the nodulizing of the fine-particle-size graphite. This gap area is the main nodulizing area, where the graphite is kneaded and deburred; there is the above-mentioned air supply port 17 at the bottom side of the nodulizing cavity 11. In order to maintain the negative pressure state in the nodulizing cavity housing 1, by setting the air supply port 17, a corresponding air intake mechanism is ensured to supplement the exhausted gas, and the pressure balance in the nodulizing cavity 11 can be maintained.

[0070] In this embodiment, in view of the differences between fine-grained graphite and coarse-grained graphite during the spheroidization process, a multi-layer graphite spheroidizing disc 21 is designed to enhance the spheroidization efficiency of fine-grained graphite. Based on the characteristics that there are fewer internal cracks and defects in fine-grained graphite and the spheroidization efficiency of fine-grained graphite is low during the plastic deformation process, a parallelogram-shaped grinding block 22 is set. The rhombus angles of the parallelogram are smaller and sharper, and the component velocity during the impact process between the graphite and the grinding block 22 points to the gear ring 19, and the moving distance of the graphite particles flying to the gear ring 19 is shorter, which enhances the spheroidization efficiency of fine-grained graphite. An annular groove 221 is provided on the grinding block 22, which can make the contact surface between the graphite particles and the grinding block 22 larger. In the gap area between the grinding block 22 and the gear ring 19, the air flow direction is from bottom to top, and the edge 222 at the junction of the annular groove 221 and the outer surface of the grinding block 22 can produce a striking effect on the graphite particles, so that the efficiency of plastic deformation of fine-grained graphite can be better improved during the process of being driven by the air flow, and the spheroidization effect is improved. At the same time, in view of the characteristics of fine-grained graphite, the gap between the farthest end of the grinding block 22 from the center of the graphite spheroidizing disc 21 (that is, the tip of the acute angle outside the graphite spheroidizing disc 21 in the parallelogram) and the gear ring 19 is shortened and designed to be 3 mm. Furthermore, it is more conducive to improving the characteristics that fine-grained graphite is not easy to undergo plastic deformation, and the spheroidization efficiency of fine-grained graphite is increased.

[0071] Further, referring to Figure 1 , an impeller driving device 38 is also provided at the top of the housing 1. The impeller driving device 38 can be connected to the rotating shaft 34 and is used to drive the grading cage impeller 3 to rotate; a grinding disc driving device is provided at the bottom of the housing 1, and the grinding disc driving device can be connected to the grinding disc structure 2 and is used to drive the grinding disc structure 2 to rotate.

[0072] The impeller driving device 38 includes an impeller driving motor 381, which is provided at the top of the housing 1 and above the tail powder discharge pipe 16. The upper end of the rotating shaft 34 sequentially passes through the above-mentioned air outlet 15 and the tail powder discharge pipe 16 and is connected to the driving motor.

[0073] The grinding disc driving device includes a transmission component and a grinding disc driving motor. The transmission component includes a driving pulley and a driven pulley 23 arranged vertically in the axial direction, an annular belt connected between the driving pulley and the driven pulley 23, and a transmission shaft 24 arranged vertically in the axial direction. The annular belt is tensioned in the horizontal direction. The lower end of the transmission shaft 24 is connected to the driven pulley 23, and the upper end of the transmission shaft 24 passes through the bottom of the housing 1 and is connected to the graphite nodulizing disc 21 at the bottom layer. Specifically, a keyway is provided on the side wall of the upper end of the transmission shaft 24, and the graphite nodulizing disc 21 is connected to the transmission shaft 24 by a key. The grinding disc driving motor is connected to the driving pulley to drive the driving pulley to rotate, and then transmits power to the driven pulley 23 through the annular belt. The rotation of the driven pulley 23 drives the transmission shaft 24 to rotate, and the torque is transmitted from the transmission shaft 24 to the graphite nodulizing disc 21 through the key to drive the graphite nodulizing disc 21 to rotate.

[0074] A chassis 18 is also connected to the bottom of the housing 1 for supporting on the ground, and the above-mentioned grinding disc driving motor is arranged on the chassis 18. A support cylinder 25 is also provided at the center of the bottom of the housing 1. The top of the support cylinder 25 extends into the housing 1. A bearing 26 is provided in the support cylinder 25. The upper end of the transmission shaft 24 passes through the bearing 26 and then extends into the housing 1. The transmission shaft 24 provides support and bears the weight and force of the driven pulley 23. The bearing 26 bears loads from all directions while significantly reducing the friction between the transmission shaft 24 and other components and fixes the position of the transmission shaft 24. A flow dividing ring 27 can also be provided inside the bottom of the housing 1 and below the grinding disc structure 2. The flow dividing ring 27 is fixed on the transmission shaft 24 by threaded connection.

[0075] Of course, the impeller driving device 38 and the grinding disc driving device can also adopt other structural forms, as long as it is convenient to drive the grading cage impeller 3 to rotate and drive the grinding disc structure 2 to rotate. This embodiment is only for illustration.

[0076] A grading cage impeller 3 is provided in the nodulizing cavity 11. The grading cage impeller 3 is located above the graphite nodulizing disc 21 and close to the top of the nodulizing cavity 11 to discharge the tail powder whose particle size is extremely fine and can no longer form balls. The grading cage impeller 3 is connected to the impeller driving motor 381 through a rotating shaft 34, and the tail powder discharge pipe 16 is arranged between the grading cage impeller 3 and the impeller driving motor 381.

[0077] Generally, a tail powder dust collector 7 is also connected to the middle of the tail powder discharge pipe 16, and a finished product dust collector 8 is also connected to the end of the finished product discharge pipe 14 far from the housing 1. The discharge port of the finished product dust collector 8 is the outlet for fine particle size spherical graphite products. The ash discharge port of the finished product dust collector 8 is connected to the feed port of the tail powder dust collector 7 through a corresponding pipeline. A vacuum conveyor 5 can also be connected to the top feed port of the silo 4.

[0078] Furthermore, the grading mechanism of the fine particle size graphite is analyzed as follows:

[0079] Not only does the fineness of different scales affect the spheroidization process, but the current particle size of spherical graphite products shows a multi-polarization development trend. The reason is the difference in the force on graphite of different particle sizes, resulting in different movement trajectories in the spheroidization cavity 11. When the batch spheroidization equipment is operating, the induced draft fan 6 connected to the tail powder discharge pipe 16 generates a negative pressure, forming an upward air flow inside the spheroidization cavity 11. After the material is fed from below and spheroidized in the spheroidization area where the graphite spheroidization disk 21, the grinding block 22, and the gear ring 19 are located, due to the different volume forces of materials with different particle sizes, the collision of coarse particle size graphite in the spheroidization area is very obvious, while the fine particle size graphite only stays in the spheroidization area for a short time. After passing through the spheroidization area, the material continues to rise under the negative pressure of the induced draft fan 6 and the swirling flow generated by the high-speed rotation of the graphite spheroidization disk 21, and enters the transition area between the classification area where the classification cage impeller 3 is located and the spheroidization area. There is no obvious boundary between the transition area and the spheroidization area and the classification area. The role of the transition area is to make the particles flow back and forth in the spheroidization cavity 11. After graphite of different particle sizes enters the transition area with the air flow, their movement trajectories change. The graphite with a smaller particle size has better followability with the air flow, and the particle movement trajectory in the transition area is smooth and the residence time in the transition area is short; the graphite with a larger particle size has poor followability with the air flow, the movement trajectory of the coarse particle size graphite in the transition area is disordered, and the movement trajectory of the finer particle size graphite in the transition area is longer, and the swirling and residence time in the transition area is longer.

[0080] The difference in graphite spheroidization is not only reflected in the different movement trajectories of graphite in the spheroidization area and the transition area, but especially obvious in the classification process. The process of graphite entering the batch spheroidization equipment and being classified is a probabilistic event. When the material rises from the transition area to the classification area, the material will be subjected to an outward centrifugal force generated by the high-speed rotation of the classification cage impeller 3 in the horizontal direction,

[0081]

[0082] In the formula, is the density of the graphite particle, r is the rotation radius of the graphite particle in the circular motion in the classification area, w is the angular velocity of the graphite particle, is the diameter of the spherical graphite particle with the same volume as the graphite particle.

[0083] At the same time, the high-speed rotating air flow will generate a horizontal drag force (F Y ) towards the inner side of the classification cage impeller 3, and its expression is:

[0084]

[0085] In the formula, ρ is the density of the gas around the graphite particles, V is the relative velocity between the graphite particles and the surrounding gas, and A is the projected area of the graphite particles in the direction of motion (i.e., the vertical direction). is the drag coefficient. There are different drag coefficient values in the three regions of the laminar flow region, transition region, and turbulent flow region with different Reynolds numbers (Re). Since the internal flow state in the spheroidizing cavity 11 belongs to a turbulent flow with medium intensity, the turbulent flow region = 0.44.

[0086] In the vertical direction, the graphite in the classification area is subjected to the gravitational force of the negative pressure of the induced draft fan 6 (neglecting the air volume loss), the suspension force and the gravity when the graphite particles are suspended in the air. The resultant force on the graphite particles is expressed as

[0087]

[0088] In the formula, Q is the suction force of the induced draft fan 6, is the efficiency of the induced draft fan 6. The above formulas are all for the force analysis of a single graphite particle.

[0089] According to the force balance, F 离心 = F Y , the following classification particle size formula can be obtained:

[0090]

[0091] Using this classification particle size formula can be used to calculate the particle size (equivalent particle size) of the classified fine particle size graphite product.

[0092] Since the mass of the fine particle size graphite is less than that of the coarse particle size graphite, from the above formula, it can be seen that at the same rotation radius, the centrifugal force in the horizontal direction is small, and there is a greater probability of entering the inside of the classification cage impeller 3 under the action of the drag force in the horizontal direction, and entering the tail powder dust collector 7 through the air outlet 15 and the tail powder discharge pipe 16 for collection, becoming the tail material; the graphite material with a larger particle size has a greater centrifugal force at the same rotation radius, so there is a greater probability of being thrown out of the periphery of the classification cage impeller 3 and falling into the transition area and then being spheroidized again through the spheroidizing area.

[0093] Regarding the differences between the coarse particle size and fine particle size spherical graphite, although adjusting the rotation speed of the classification cage impeller 3 and the air volume parameters of the induced draft fan 6 can improve the differences between the coarse particle size and fine particle size graphite during the classification process, taking the fine particle size graphite as an example, if only relying on increasing the rotation speed of the classification cage impeller 3 to reduce the particle size of the crushed particles, a higher classification rotation speed will inevitably cause an increase in the flow path resistance of the impeller, resulting in an increase in the output power of the induced draft fan 6.

[0094] In particular, the particle size of fine-grained spherical graphite is generally about 10 μm. The finer the particle size of the particles, the larger the specific surface area and the higher the surface energy. The high surface energy causes the tail powder or the fine-grained graphite itself to agglomerate into fine-grained spherical graphite clusters, or the tail powder or the fine-grained graphite adheres to the fine-grained graphite. The fine-grained spherical graphite clusters agglomerated by the tail powder or the fine-grained graphite, or the tail powder or the fine-grained graphite adhering to the fine-grained graphite will be classified into the fine-grained products together, forming a "fishhook effect" in the Tromp curve, resulting in a decrease in the classification efficiency of the fine-grained graphite and affecting the product qualification rate. Due to the agglomeration of the tail powder or the fine-grained graphite itself, or the adhesion to the spherical graphite of other particle sizes, the dispersion of the spherical graphite in the machine body becomes poor, reducing the classification accuracy.

[0095] In this embodiment, through the cooperation of the classification cage impeller 3, the guide member 36, the auxiliary blade 35 and the guide blade 37 and the setting of each structural parameter, the classification of particles can be made more precise during the spheroidization process of the material in the spheroidization cavity 11, effectively improving the spheroidization rate of qualified fine-grained natural graphite.

[0096] To better reflect the effect of this equipment, the following provides some test data:

[0097] To explore the material properties and evolution laws of the batch spheroidization equipment in this embodiment during the spheroidization of fine-grained spherical graphite, the two-mouth material with a particle size distribution of 8-10 μm was used as the raw material, and tests were carried out in the batch spheroidization equipment according to different test parameters, and continuous operation was carried out under a single operating parameter. The particle size, tapped density and partial morphology evolution results are shown in Table 1 and Figure 8 and Figure 13 as shown.

[0098] Through Figures 8 to 13 It can be seen from the SEM images shown that the surface of the fine-grained spherical graphite after crushing and spheroidization by the batch spheroidization equipment is very smooth, and there are no smaller tail powder particles attached to its surface, indicating that under the action of the guide member 36, the auxiliary blade 35 and the guide blade 37, the material adhered to the surface of the fine-grained spherical graphite due to high surface energy can be dispersed in the classification area to achieve fine classification.

[0099] Table 1 Test parameters and results of the fine-grained two-mouth material entering the batch spheroidization equipment in this embodiment

[0100]

[0101] Among them, the main machine frequency in Table 1 refers to the rotation frequency of the grinding disc structure 2, the classification frequency refers to the rotation frequency of the classification cage impeller 3, and the fan frequency refers to the frequency of the induced draft fan 6. The yield, that is, the recovery rate, that is, the spheroidization rate, is equal to the discharge amount / feed amount.

[0102] By analyzing the test results in Table 1, it can be seen that the product particle size has not been further reduced, and the tapped density of the product under both test parameters has increased by about 0.4 g / cm 3 after 10 minutes of batch spheroidization, indicating that the fine-grained graphite no longer breaks in the equipment, mainly undergoes spheroidization, and the equipment has good tapping effect. Under the action of the classification cage impeller 3, the raw material can avoid a large amount of passing through the classification cage impeller 3 and entering the tail material without significantly increasing the classification frequency. It repeatedly collides and embeds in the spheroidization cavity 11 to form spheres, and the spheroidization rate reaches more than 70%. At the same time, the particle size distribution rises, the tapped density increases, and the morphology becomes more regular. The results show that the spheroidization effect of the equipment in this embodiment dedicated to fine-grained graphite is good. It can process 20 kg of materials in 2.5 minutes. Considering the time for material feeding and discharging of 1 minute per single time, the single-machine processing capacity can reach 340 kg / h, and the tapped density of the spherical graphite product can be increased from 0.48 g / cm 3 to 0.7 g / cm 3 or above, and the yield remains above 75%.

[0103] In summary, the equipment in this embodiment is a high-efficiency batch spheroidization equipment dedicated to fine-grained spherical graphite. Compared with the prior art, it has the following advantages:

[0104] (1) In the current existing graphite spheroidization technology, there is no dedicated spheroidization equipment for fine-grained spherical graphite, resulting in insufficiently fine classification during the batch spheroidization process of fine-grained graphite, causing fine-grained spherical graphite to be classified into tail powder, or tail powder or fine-grained spherical graphite agglomerates being regarded as fine-grained products, or tail powder or finer particles adhering to the fine-grained spherical graphite and then entering the spheroidization area again, resulting in failure to meet the product specification requirements and low qualified spheroidization rate and low yield of fine-grained spherical graphite products. The equipment in this embodiment uses the classification cage impeller 3 to specifically classify fine-grained particles, reducing the inhalation of fine-grained spherical graphite into the tail powder, and dispersing the agglomerated fine-grained spherical graphite through the flow guide 36, auxiliary blades 35, guide vanes 37 and make-up air, improving the problem of low qualified spheroidization rate of fine-grained spherical graphite.

[0105] (2)During the spheroidization process of this equipment, considering the differences between fine-grained graphite and coarse-grained graphite, a multi-layer graphite spheroidization disk 21 is designed to enhance the spheroidization efficiency of fine-grained graphite. Based on the characteristics that there are fewer internal cracks and defects in fine-grained graphite and the low efficiency of fine-grained graphite during plastic deformation, a parallelogram-shaped grinding block 22 is set. An annular groove 221 is provided on the grinding block 22, and the corresponding edge 222 at the annular groove 221 can better improve the efficiency of plastic deformation of fine-grained graphite. At the same time, considering the characteristics of fine-grained graphite, the gap between the farthest end of the grinding block 22 away from the center of the graphite spheroidization disk 21 and the gear ring 19 is shortened and set to 3 mm. The graphite spheroidization disk 21 is driven by a transmission component to rotate at a high speed, so that the material is hit by the grinding block 22 installed on the graphite spheroidization disk 21 and the gear ring 19 after passing through the feed pipe 13. Then, due to the high-speed swirling action, the material is thrown up and circulates in the spheroidization chamber housing 1 from top to bottom. Through a single device, the relatively large-sized second-grade material in the classified fine and irregular fine-grained graphite is spheroidized into fine-grained spherical graphite, and the small flaky graphite is kneaded into an oval or spherical-like graphite, and the yield is above 70%, realizing the reuse of the second-grade material (since the raw material of this equipment is fine and irregular fine-grained graphite, which is the tail powder obtained through the crushing, spheroidization and classification treatment of multiple previous devices, it can also be called the second-grade material). In addition, since the equipment is a single machine, the length of the entire production line is reduced, the cost input is reduced, and at the same time, the spheroidization rate of the fine-grained spherical graphite is increased.

[0106] (3)In the existing graphite spheroidization technology, the method of connecting multiple spheroidization devices in series is mostly used. This equipment uses a single device for batch spheroidization, greatly reducing the number of machines and the cost during the spheroidization process.

[0107] The above are only the schematic specific implementation manners of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A fine-grained graphite batch spheroidizing device, characterized in that: Used to produce fine-grained spherical graphite products, wherein the particle size volume distribution of the fine-grained spherical graphite products satisfies the median particle size of 7-13 μm, and the fine-grained graphite batch spheroidizing equipment includes a shell having a spheroidizing cavity; A rotatable grinding disc structure and a rotatable graded cage impeller are respectively provided at the bottom and the top of the spheroidizing cavity, and the graded cage impeller comprises a rotating shaft, a top frame and a bottom plate spaced apart from each other, and a diverter fence connected between the top frame and the bottom plate; the rotating shaft is fixedly connected to the bottom plate, and its lower end extends out of the bottom plate and is connected with an auxiliary blade assembly and a flow guide arranged up and down, and the flow guide is a water drop-shaped structure with a rounded lower end and a gradually narrowed upper end; the auxiliary blade assembly comprises a plurality of auxiliary blades spaced apart circumferentially on the rotating shaft and can cause the airflow to form a vortex; An annular graded flow guide assembly is provided at the outer periphery of the graded cage impeller and close to the inner wall of the spheroidizing cavity, the graded flow guide assembly comprises a plurality of flow guide blades arranged at intervals in the circumferential direction, and the plate surface of each of the flow guide blades is inclined relative to the corresponding radial direction in the spheroidizing cavity and the inclination direction is the same; the flow guide blade is a rectangular plate body with a plate surface vertically arranged, and the inclination angle range of the plate surface of the flow guide blade relative to the corresponding radial direction in the spheroidizing cavity is 66-75°; The grinding disc structure includes at least two layers of graphite spheroidizing discs arranged at intervals in the upper and lower directions, and a plurality of grinding blocks are circumferentially spaced on the top surface of the graphite spheroidizing disc; an annular gear ring is provided on the inner wall of the spheroidizing cavity facing the grinding disc structure; the cross section of the grinding block is a parallelogram, and a plurality of annular grooves are spaced from top to bottom on the outer side wall of the grinding block, and a portion of the grinding block extends out of the outer peripheral edge of the graphite spheroidizing disc and leaves a gap of 3 mm between the gear ring.

2. The fine-grained graphite batch spheroidizing equipment according to claim 1, characterized in that: The diverter fence includes a plurality of diverter rods evenly spaced circumferentially, and the two ends of the diverter rods are respectively connected to the outer edge positions of the top frame and the bottom plate; the graded cage impeller is an inverted cone structure with an outer diameter gradually increasing from bottom to top.

3. The fine-grained graphite batch spheroidizing equipment according to claim 2, characterized in that: The rotation speed of the graded cage impeller is less than or equal to 3000 r / min.

4. The fine-grained graphite batch spheroidizing equipment according to claim 1, characterized in that: The cross section of the shell is circular, and the inner wall of the shell includes a first cylindrical surface, a conical surface with a diameter increasing from bottom to top, and a second cylindrical surface connected in sequence from bottom to top. The grinding disc structure is arranged opposite to the first cylindrical surface, and the graded cage impeller is arranged opposite to the second cylindrical surface.

5. The fine-grained graphite batch spheroidizing equipment according to claim 1, characterized in that: A feed pipe and a finished product discharge pipe can be connected in a disconnectable manner at a position on the side of the shell corresponding to the area between the grading cage impeller and the grinding disc structure; an air outlet is provided at a position on the top of the shell facing the grading cage impeller, and a tail powder discharge pipe can be connected in a disconnectable manner; a discharge valve is provided on the finished product discharge pipe, and the discharge valve can be automatically opened after a preset time of material spheroidization to complete the discharge; The tail powder discharging pipe is also connected with an induced draft fan, and the bottom of the shell is also provided with an air supply port which can be communicated with the spheroidizing cavity.

6. The fine-grained graphite batch spheroidizing equipment according to claim 5, characterized in that: The end of the feed pipe away from the shell is also connected to a hopper, the hopper is connected to the first end of the screw conveyor, the second end of the screw conveyor is connected to a silo, the lower part of the silo is a cone with an inner diameter that tapers downward, and an air disc is provided on the inner wall of the cone.

7. The fine-grained graphite batch spheroidizing equipment according to claim 1, characterized in that: An impeller driving device is also provided on the top of the shell, and the impeller driving device can be connected to the rotating shaft and used to drive the graded cage impeller to rotate; a grinding disc driving device is provided at the bottom of the shell, and the grinding disc driving device can be connected to the grinding disc structure and used to drive the grinding disc structure to rotate.

Images