Vertical mill for grinding petroleum coke

Abstract

The utility model discloses a vertical mill for grinding petroleum coke, and belongs to the technical field of grinding equipment. The vertical mill comprises: a housing; the grinding disc is rotationally located in the machine shell; the grinding roller assembly is located in the portion, above the grinding disc, of the machine shell, and the grinding roller assembly is in rolling contact with the grinding disc and used for grinding petroleum coke; the powder selecting machine is positioned at the upper part of the machine shell and is used for screening the ground petroleum coke particles; the top of the edge of the grinding disc is detachably connected with a material blocking ring assembly with the adjustable height. The height-adjustable material blocking ring assembly is arranged at the top of the edge of the millstone, it can be guaranteed that petroleum coke can form a material layer with a certain thickness on the millstone, in this way, milling of the milling roller assembly can be facilitated, the mill does not have large vibration during operation, meanwhile, the wind effect can be reduced, and the service life of the mill is prolonged. And fine powder which does not meet the requirement falls back to the grinding disc again to be ground continuously.

Description

Technical Field

[0001] The utility model belongs to the technical field of grinding equipment and relates to a vertical mill for grinding petroleum coke. Background Art

[0002] Petroleum coke is a by-product in the process of petroleum refining, with a large output and low value, and its main component is carbon. Petroleum coke is mainly used for graphite electrodes, pre-baked anodes for steel plants, fuels for cement plants and power plants, etc. With the continuous increase of its output, the market demand has gradually saturated, and people have begun to study the high-value-added applications of petroleum coke. Among them, the research on petroleum coke as the negative electrode material of lithium-ion batteries shows great application prospects.

[0003] For high-quality petroleum coke to be used as the negative electrode material of lithium-ion batteries, generally processes such as purification, pulverization, particle size screening, graphitization, and surface modification are required. Relevant research shows that the optimal particle size of petroleum coke as the negative electrode material of lithium batteries is 10 - 20 microns. Therefore, it is necessary to use grinding equipment to grind the petroleum coke raw material to a qualified particle size.

[0004] For such non-metallic mineral ultrafine powder processing, ultrafine grinding and fine classification equipment in China mainly include Raymond mills, stirred mills, vibration mills, ring-roll mills, ball mills, and vertical mills (referred to as vertical mills for short). Among them, the Raymond mill is one of the mainstream equipment for processing powder products below 325 mesh; the vibration mill and the stirred mill equipped with a classifier can be used to process products with a mesh size of 600 - 2500, but their capacity is relatively small and the energy consumption is relatively high, mainly used for processing materials with special hardness; the ball mill plus an ultrafine classifier can process ultrafine powder with a mesh size of 600 - 2500 at one time, with a large single-machine production capacity and stable and reliable performance, but the energy consumption is slightly high; the ring-roll mill is mainly used for processing products with a mesh size of 600 - 500, with the advantages of low investment price and low energy consumption, but the single-machine production capacity is not large enough.

[0005] The vertical mill is an ideal modern grinding equipment, mainly used in multiple industries such as cement, electric power, metallurgy, chemical industry, and non-metallic minerals. Its design integrates crushing, drying, grinding, classification, and transportation, and can effectively grind lumpy, granular, and powdery raw materials into the required powdery materials. Compared with grinding other materials, petroleum coke has a small density and the finished product requires a very fine particle size. Using a conventional type of vertical mill to grind petroleum coke is extremely likely to cause an excessive amount of returned powder, and it is very difficult for the returned powder to be stabilized on the material bed under the action of air and cannot be reground by the grinding roller.

[0006] Therefore, it is necessary to provide a vertical mill that can reduce the amount of returned fine powder of petroleum coke. Summary of the Utility Model

[0007] In order to at least solve the problem that the returned powder generated by the vertical mill for grinding petroleum coke in the above-mentioned prior art is difficult to be stabilized on the material bed under the action of wind and cannot be reground by the grinding roller, the present utility model provides the following technical solutions: A vertical mill for grinding petroleum coke, the vertical mill includes:

[0008] A housing;

[0009] A grinding table, the grinding table rotates and is located inside the housing;

[0010] A grinding roller assembly, the grinding roller assembly is located inside the housing above the grinding table, the grinding roller assembly is in rolling contact with the grinding table and is used for grinding petroleum coke;

[0011] A powder separator, the powder separator is located in the upper part of the housing and is used for screening the ground petroleum coke particles;

[0012] Wherein, a baffle ring assembly with adjustable height is detachably connected to the top of the edge of the grinding table.

[0013] Optionally, in the above-mentioned vertical mill for grinding petroleum coke, the baffle ring assembly is composed of multiple layers of baffle rings, and the multiple layers of baffle rings are stacked on the top of the edge of the grinding table;

[0014] The baffle ring is fixed on the grinding table by bolts.

[0015] Optionally, in the above-mentioned vertical mill for grinding petroleum coke, multiple layers of baffle rings with different thicknesses are stacked on the top of the edge of the grinding table.

[0016] Optionally, in the above-mentioned vertical mill for grinding petroleum coke, the vertical mill further includes: a water spraying system;

[0017] The water spraying system is installed inside the housing and is used for spraying water towards the grinding table.

[0018] Optionally, in the above-mentioned vertical mill for grinding petroleum coke, the water spraying system includes: a water delivery pipe, a sealing plate, a protection plate and a wind protection plate;

[0019] One end of the water delivery pipe is communicated with a water source, the other end of the water delivery pipe penetrates into the housing above the grinding table, and multiple water spraying holes are arranged on the side wall of the water delivery pipe;

[0020] The sealing plate covers the other end of the water delivery pipe;

[0021] The wind protection plate is located on the windward side of the water delivery pipe;

[0022] The protection plate is located on the leeward side of the water delivery pipe, and the protection plate is connected to the wind protection plate through a connecting piece.

[0023] Optionally, in the vertical mill for grinding petroleum coke described above, the roller assembly includes: a roller, a roller sleeve, and a rocker arm;

[0024] A plurality of the rollers are circumferentially distributed along the center line of the housing. The rollers are located above the grinding table, and the axes of the rollers are arranged at an angle to the horizontal plane;

[0025] The roller sleeve is sleeved on the outside of the roller;

[0026] One end of the rocker arm is connected to the roller, and the other end of the rocker arm is connected to the loading system.

[0027] Optionally, in the vertical mill for grinding petroleum coke described above, the vertical mill further includes: an air ring, and the air ring includes: an inner ring, an outer ring, and connecting blades;

[0028] The inner ring is installed on the grinding table;

[0029] The outer ring is sleeved on the circumferential outside of the inner ring, and a cavity is formed between the outer ring and the inner ring. The connecting blades are arranged in the cavity;

[0030] The connecting blades are inclined, and the rotation direction of the connecting blades is the same as that of the static blades in the classifier.

[0031] Optionally, in the vertical mill for grinding petroleum coke described above, the classifier includes: moving blades, a rotor, a return powder cone, static blades, and a variable frequency motor;

[0032] A powder outlet is provided at the upper part of the housing;

[0033] One end of the central shaft of the rotor passes through the top of the housing and is connected to the variable frequency motor;

[0034] A plurality of the moving blades are all located on the rotor;

[0035] A plurality of the static blades are circumferentially distributed along the moving blades. The static blades are arranged at an angle to the horizontal plane, and one end of the static blades is connected to the top of the housing;

[0036] One end of the return powder cone is connected to the other end of the static blade, and the other end of the return powder cone is connected to a discharger located outside the housing through a feeding pipeline;

[0037] The return powder cone is 400 - 600 mm away from the conical manhole cover located at the center of the grinding table.

[0038] Optionally, in the vertical mill for grinding petroleum coke described above, the vertical mill further includes: an explosion-proof gas pipeline;

[0039] A hopper and a slag discharge box are arranged in the housing;

[0040] A plurality of support plates are provided on the inner wall of the hopper for placing the air ring.

[0041] An opening is provided on one side of the hopper below the air ring, and the opening communicates with a hot air inlet on the casing.

[0042] The explosion-proof gas pipeline communicates with the classifier and the hot air inlet respectively.

[0043] The slag discharge box is located below the hot air inlet, and the slag discharge box communicates with a slag discharge port at the bottom of the hopper for receiving slag.

[0044] Optionally, in the vertical mill for grinding petroleum coke described above, the vertical mill further includes: a sealing system;

[0045] The sealing system includes: a sealing fan and a sealing air pipeline;

[0046] The output end of the sealing fan is connected to one end of the sealing air pipeline;

[0047] The other end of the sealing air pipeline communicates with the sealing air inlet of the roller assembly;

[0048] A flow regulating valve is provided at the sealing air inlet of the roller assembly for controlling the flow rate of the sealing air.

[0049] The beneficial effects brought by the technical solution provided by the embodiment of the present invention are:

[0050] By providing a baffle ring assembly with adjustable height at the top edge of the grinding table in this application, it can ensure that the petroleum coke can form a certain thickness of material layer on the grinding table, which is convenient for the grinding of the roller assembly, and the mill will not have large vibrations during operation. At the same time, the effect of the wind can be reduced, so that the fine powder that does not meet the requirements can fall back onto the grinding table and continue to be ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a front view structural schematic diagram of a vertical mill for grinding petroleum coke provided by an embodiment of the present invention;

[0052] Figure 2 is a rear view (partial) structural schematic diagram of a vertical mill for grinding petroleum coke provided by an embodiment of the present invention;

[0053] Figure 3 is Figure 1 a structural schematic diagram of the classifier in

[0054] Figure 4 is a schematic diagram of the positional relationship between the roller and the lining plate in a vertical mill for grinding petroleum coke provided by an embodiment of the present invention;

[0055] Figure 5 Schematic position diagram of the water spraying system in a vertical mill for grinding petroleum coke provided by an embodiment of the present utility model;

[0056] Figure 6 Schematic specific structure diagram of the water spraying system in a vertical mill for grinding petroleum coke provided by an embodiment of the present utility model;

[0057] Figure 7 For Figure 6 left view of;

[0058] Figure 8 Schematic position diagram of the baffle ring assembly in a vertical mill for grinding petroleum coke provided by an embodiment of the present utility model;

[0059] In the figure: 1, mill foundation; 2, main motor; 3, main speed reducer; 4, support; 5, rocker arm; 6, grinding roller; 7, grinding table; 701, lining plate; 8, tensioning oil cylinder; 9, casing; 10, classifier; 1001, moving vane; 1002, rotor; 1003, return powder cone; 1004, static vane; 11, hot air inlet; 12, hopper; 13, water spraying system; 1301, water delivery pipe; 1302, sealing plate; 1303, guard plate; 1304, windproof plate; 1305, connecting piece; 14, maintenance platform; 15, barring gear; 16, slag discharge box; 17, seal air pipeline; 18, explosion-proof gas pipeline; 19, bridge; 20, coupling; 21, roll turning oil cylinder; 22, air ring; 23, feed pipeline; 24, powder outlet; 25, star-shaped unloader; 26, baffle ring; 27, scraper; 28, slag discharge port; 29, wind baffle. Detailed implementation manners

[0060] To make the objectives, technical solutions and advantages of the present utility model clearer, the embodiments of the present utility model will be described in further detail below in conjunction with the accompanying drawings.

[0061] In the description of the present utility model, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model rather than requiring the present utility model to be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present utility model. The terms "connected", "connected to", and "disposed" used in the present utility model should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate component; it can be a wired electrical connection, a radio connection, or a wireless communication signal connection. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0062] Please refer toFigure 1-8 , the present utility model provides the following technical solutions: A vertical mill for grinding petroleum coke, the vertical mill includes: a casing 9, a grinding table 7, a grinding roller assembly, and a classifier 10. The mill foundation 1 fixes the mill on the ground through anchor bolts, and the bottom of the casing 9 is connected to the mill foundation 1 through a plurality of brackets 4. A bridge 19 is arranged between the brackets 4 for wiring and providing protection for the power system. For easy maintenance, a maintenance platform 14 is arranged circumferentially on the brackets 4 and the bridge 19. The grinding table 7 rotates inside the casing 9, and the rotation of the grinding table 7 can be realized by a motor, and the motor is not limited in this embodiment. The top of the edge of the grinding table 7 is detachably connected with a baffle ring assembly whose height can be adjusted. In actual operation, the height of the baffle ring assembly can be flexibly adjusted according to the operation conditions of the mill. The grinding roller assembly is located inside the casing 9 above the grinding table 7, and the grinding roller assembly is in rolling contact with the grinding table 7 for grinding petroleum coke. A loading force can be output to the grinding roller assembly through a loading system to drive the grinding roller assembly to press down on the petroleum coke, so that the petroleum coke is crushed under rolling, and the specific structure of the loading system is not limited in this embodiment, and a commonly used loading system in the art can be adopted. The classifier 10 is located in the upper part of the casing 9. It can be understood that the housing of the classifier 10 is a part of the casing 9. As Figure 1 shown, the classifier 10 is also located above the grinding roller assembly (referring to the grinding roller 6). The classifier 10 is used to screen the ground petroleum coke particles. The existing classifier 10 can be adopted for the classifier 10, and it is not limited in this embodiment. During use, an appropriate amount of petroleum coke raw material is added into the classifier 10, and the petroleum coke raw material falls into the center of the grinding table 7 through the classifier 10 to form a material layer. Under the action of the loading system, the grinding roller assembly (referring to the grinding roller 6) is lowered, and the grinding table 7 rotates continuously. Under the action of centrifugal force, the petroleum coke raw material moves towards the edge of the grinding table 7. During the movement, the petroleum coke raw material is crushed into particles under the rolling of the grinding roller assembly. When the petroleum coke particles move to the edge of the grinding table 7, they leave the grinding table 7 and move upward under the action of the high-speed hot air flow ejected from the air ring 22. The larger particles directly fall onto the grinding table 7 for re-grinding, and the smaller particles follow the air flow to reach the classifier 10. After being screened by the classifier 10, the qualified petroleum coke fine powder exits from the powder outlet of the classifier 10 along with the air flow and is collected by a dust collection device (not shown in the figure). Due to the shielding of the baffle ring assembly, the effect of the wind is reduced, so that the unqualified fine powder falls back onto the grinding table 7 (these fine powders are also called return powder) for continuous grinding. During the process of grinding petroleum coke, the baffle ring assembly can ensure that the petroleum coke can form a material layer with a certain thickness on the grinding table 7, which is convenient for the grinding of the grinding roller assembly, and the mill will not have large vibrations during operation.

[0063] Refer to Figure 8As shown in the figure, as an embodiment of the specific structure of the above-mentioned material retaining ring assembly with adjustable height, in this embodiment, the material retaining ring assembly is composed of multiple layers of material retaining rings 26. The multiple layers of material retaining rings 26 are stacked on the top edge of the grinding table 7. At the same time, holes for clamping bolts are drilled in the material retaining rings 26. During installation, bolts are passed through the holes in the stacked multiple layers of material retaining rings 26 to fix the multiple layers of material retaining rings 26 on the grinding table 7. If it is necessary to adjust the height of the material retaining ring 26, then the bolts need to be removed, some of the material retaining rings 26 need to be removed, and then they can be fixed again by clamping with bolts.

[0064] As a preference of the above embodiment, in this embodiment, multiple layers of material retaining rings 26 with different thicknesses are stacked on the top edge of the grinding table 7. It should be noted that in actual operation, the height of the material retaining ring 26 is flexibly adjusted according to the operation conditions of the mill: Firstly, it is necessary to ensure that the petroleum coke can form a certain thickness of material layer on the grinding table 7, so as to facilitate the grinding of the grinding rolls 6 and the mill will not vibrate greatly during operation; Secondly, a reasonable amount of slag discharge also needs to be controlled. The higher the material retaining ring 26, the more sufficient the grinding will be and the less the slag discharge will be, but the more difficult it will be for the difficult-to-grind materials to cross the material retaining ring 26 and it will not be easy to discharge them. Preferably, a steel plate is also provided between the material retaining ring 26 and the grinding table 7. The material retaining ring 26 and the steel plate are fixed on the grinding table 7 by bolts. The width of the steel plate is greater than the width of the material retaining ring 26. According to the operation conditions of the mill, such as removing the steel plate, cutting a part of it, or extending (the width) by a part, the air flow area can be changed, so as to achieve the purpose of adjusting the wind speed. In addition, a surfacing layer is provided on the windward surface of the steel plate, which has the function of wear resistance.

[0065] Refer to Figure 1 and Figure 5 As shown in the figure, the vertical mill further includes: a water spraying system 13. The water spraying system 13 is installed in the casing 9 and is used to spray water towards the grinding table 7.

[0066] As an embodiment of the specific structure of the above-mentioned water spraying system 13, refer to 6 and Figure 7As shown in the figure, in this embodiment, the water spraying system 13 includes a water delivery pipe 1301, a sealing plate 1302, a protection plate 1303 and a wind protection plate 1304. One end of the water delivery pipe 1301 is communicated with a water source, and the other end of the water delivery pipe 1301 penetrates into the casing 9 above the grinding table 7. A plurality of water spraying holes are arranged on the side wall of the water delivery pipe 1301. The number and aperture of the water spraying holes can be set according to actual needs. The sealing plate 1302 covers the other end of the water delivery pipe 1301 (the end far from the water source). The wind protection plate 1304 is located on the windward side of the water delivery pipe 1301, and the protection plate 1303 is located on the leeward side of the water delivery pipe 1301. The protection plate 1303 is connected with the wind protection plate 1304 through a connecting member 1305. It should be noted that in actual arrangement, the wind protection plate 1304 is located above the wind ring 22, and the water spraying holes on the water delivery pipe 1301 are arranged in the area of the lining plate 701 of the grinding table 7. Preferably, a solenoid valve is installed on the water delivery pipe 1301 to control the water supply. The connecting member 1305 includes a bolt, a nut, a flat washer and a spring washer. One end of the bolt is connected with the wind protection plate 1304. After the other end of the bolt passes through the protection plate 1303, the spring washer and the flat washer are sleeved on the bolt in sequence, and finally the bolt is connected with the nut. During the operation of the mill, water is sprayed onto the surface of the grinding table 7 through the water spraying holes on the water delivery pipe 1301, so as to stabilize the material layer and reduce the vibration value of the mill. Hot air is introduced into the mill to dry the pulverized petroleum coke fine powder, so that the moisture content of the product is kept within 1%. At the same time, the wind protection plate 1304 can reduce the blowing damage of the hot air from the wind ring 22 to the water delivery pipe 1301.

[0067] In order to realize the rotation of the grinding table 7, one end of the grinding table 7 is connected with a reduction motor located on the mill foundation 1, and a bowl-shaped lining plate 701 (as Figure 4 shown) is arranged at the other end of the grinding table 7. The grinding surface of the lining plate 701 is made of surfacing material. The center line of the lining plate 701 and the discharge port of the classifier 10 are on the same straight line, so that it is convenient for the lining plate 701 to receive the petroleum coke raw material. It should be noted that the reduction motor refers to the abbreviation of the main speed reducer 3 and the main motor 2. Among them, one end of the main motor 2 is connected with one end of the main speed reducer 3 through a coupling 20, and the other end of the main speed reducer 3 is connected with one end of the grinding table 7. In this way, the main speed reducer 3 can drive the grinding table 7 to rotate. In order to overhaul the mill, a barring gear device 15 (composed of a motor, a speed reducer and a three-jaw coupling) is arranged on one side of the main motor 2, and a three-jaw coupling is installed at the other end of the main motor 2. When in use, these two three-jaw couplings are engaged, and when not in use, the two three-jaw couplings are disengaged.

[0068] As an embodiment of the specific structure of the above-mentioned grinding roller assembly, in this embodiment, the grinding roller assembly includes: a grinding roller 6, a roller sleeve, and a rocker arm 5. The grinding roller 6 is in the form of a tyre roller, and a plurality of grinding rollers 6 are circumferentially distributed along the center line of the casing 9. The number of grinding rollers 6 can be determined according to the size and production capacity of the mill, and the number can be 2 rollers, 3 rollers, 4 rollers, etc. The grinding roller 6 is located above the grinding table 7, and the axis of the grinding roller 6 is arranged at an angle with the horizontal plane, and the included angle range between the two is 10° to 20°, for example: 10°, 13°, 15°, 17°, 20°. When the included angle between the two is 15° (refer to Figure 4 shown), the grinding effect is the best. The roller sleeve is sleeved on the outside of the grinding roller 6. The grinding surface of the roller sleeve is made of wear-resistant surfacing material, and the surface is welded with pattern textures, which can increase the grinding force between the grinding roller 6 and the petroleum coke, make the petroleum coke grinding more sufficient, reduce the amount of returned powder, and at the same time can form a more stable material bed, and extend the service life of the grinding roller 6 and the grinding table 7 (specifically referring to the liner 701 at the top of the grinding table). The outer shape of the roller sleeve is in the shape of a tyre, and the wrap angle α of the roller sleeve is not less than 120°. In this way, when the grinding roller 6 is working, the force is more uniform, the grinding area is increased, and the grinding efficiency is improved. Preferably, a water spraying system 13 is arranged between adjacent grinding rollers 6, and a plurality of water spraying systems 13 can improve the water spraying efficiency. One end of the rocker arm 5 is connected to the grinding roller 6, and the other end of the rocker arm 5 is connected to the loading system. In this way, when the grinding table 7 rotates, the grinding roller 6 rotates self-driven under the frictional force of the petroleum coke, and under the action of the self-weight of the grinding roller 6 and the loading force applied by the loading system, the grinding roller 6 squeezes and grinds the petroleum coke.

[0069] In order to convey the finely ground petroleum coke powder to the classifier 10, the vertical mill further includes: an air ring 22. Specifically, referring to Figure 8 shown, the air ring 22 includes: an inner ring, an outer ring, and connecting blades. The inner ring (that is, the ring in the air ring 22 close to the grinding table 7) is installed on the grinding table 7. The outer ring (that is, the ring in the air ring 22 far from the grinding table 7) is sleeved on the circumferential outer side of the inner ring, and a cavity is formed between the outer ring and the inner ring, and connecting blades are arranged in the cavity. The connecting blades are inclined and in the form of louvers, and the included angle between the connecting blades and the horizontal plane is not less than 45°. When the hot air introduced into the mill passes through the connecting blades, the wind speed reaches more than 30 m / s, and the smaller petroleum coke particles after grinding can be blown to the classifier 10. The rotation direction of the connecting blades (referring to the direction of the included angle formed by the connecting blades and the horizontal plane) is the same as the rotation direction of the static blades 1004 in the classifier 10 (referring to the direction of the included angle formed by the static blades 1004 and the horizontal plane), so as to facilitate the screening of the classifier 10 and enable the qualified coke powder to pass through the static blades 1004 smoothly. Preferably, a wind shield 29 is provided on the top plate of the outer ring, and the side of the wind shield 29 close to the grinding table 7 is inclined (referring to Figure 8 the direction from left to right in), and the wind shield 29 is used to reduce the blowing damage of the hot air to the casing 9.

[0070] Referring to Figure 3As shown in the figure, the powder separator 10 includes: moving blades 1001, a rotor 1002, a return powder cone 1003, static blades 1004, and a variable-frequency motor. An outlet for powder is provided at the upper part of the casing 9 (referring to the casing of the powder separator 10). A dust collection device is also provided at the outlet of the casing 9 for collecting qualified fine petroleum coke powder. One end of the central shaft of the rotor 1002 passes through the top of the casing 9 and is connected to the variable-frequency motor, and the rotor 1002 is driven by the variable-frequency motor to rotate along the central shaft. The variable-frequency motor is controlled by a frequency converter to control the rotation speed of the rotor 1002, and the rotation speed can be adjusted between 150 - 1500 r / min. A plurality of moving blades 1001 are all located on the rotor 1002, and either welding or connecting parts can be used. The moving blades 1001 can rotate in the same direction as the rotor 1002. A plurality of static blades 1004 are distributed circumferentially along the moving blades 1001. The static blades 1004 are arranged at an angle with the horizontal plane, and the angle range is 30° - 35°, for example: 30°, 31°, 32°, 33°, 35°. The preferred angle between the two is 32°. One end of the static blades 1004 is connected to the top of the casing 9. The return powder cone 1003 is in the shape of a funnel. The return powder cone 1003 is located below the rotor 1002. One end of the return powder cone 1003 is connected to the other end of the static blades 1004. The other end of the return powder cone 1003 (referring to the central pipe) leads to the grinding table 7. The central pipe of the return powder cone 1003 is connected to a star-shaped discharger 25 outside the casing 9 at the location of the powder separator 10 through an inclined feeding pipeline 23 (also called a blanking pipe). That is to say, the feeding pipeline 23 penetrates into the casing 9 from one side of the powder separator 10 and then connects to the central pipe of the return powder cone 1003, which can achieve better feeding and in-mill material return. The preferred discharger is the star-shaped discharger 25. The star-shaped discharger 25 works under negative pressure, which can play a role in uniform feeding and at the same time has the effect of airtightness. The distance between the central pipe of the return powder cone 1003 and the conical manhole cover at the center of the grinding table 7 is 400 - 600 mm, for example: 400 mm, 450 mm, 500 mm, 550 mm, 600 mm. When the distance between the two is 550 mm, it is the best. Shortening the distance between the return powder cone 1003 and the grinding table 7 can effectively solve the problem that the air flow (hot air) flows upward from the central pipe of the return powder cone 1003 to the powder separator 10 above. The functions of the conical manhole cover are: First, it is convenient for inspecting the inside of the grinding table 7 and disassembling and assembling the screws inside the grinding table 7; second, it is convenient for feeding. The petroleum coke raw material is in the form of central feeding. The manhole cover is conical, which is convenient for the petroleum coke raw material to fall to the edge of the grinding table 7 (i.e., at the grinding roller 6).During operation, an appropriate amount of petroleum coke raw material is added to the feeding port of the star-shaped unloader 25 on the side of the powder separator 10. The petroleum coke raw material is evenly discharged by the star-shaped unloader 25 and falls onto the lining plate 701 of the grinding table 7 along the feeding pipeline 23. The subsequent grinding process will not be elaborated here. The crushed petroleum coke particles move upward under the action of the high-speed hot air flow, and successively enter the annular space between the casing 9 and the powder return cone 1003, and the conical space formed by the casing 9 and the stationary blades 1004 with a gradually decreasing cross-sectional area of the circular ring from bottom to top. The conical space gradually increases the pressure of the air-powder flow, enabling it to better enter the gap between the stationary blades 1004, and then enters the separation area of the rotor 1002. The faster the speed of the rotor 1002, the smaller the particle diameter that can pass through the moving blades 1001. The qualified fine petroleum coke powder exits from the powder outlet of the powder separator 10 with the air flow and is collected by the dust collection device. The unqualified fine powder falls back onto the grinding table 7 through the powder return cone 1003 for continuous grinding. By driving the rotor 1002 to rotate at different speeds through the variable-frequency motor, the control of the fineness of the petroleum coke particles is achieved.

[0071] To meet the explosion-proof requirements, in this embodiment, the vertical mill further includes: an explosion-proof gas pipeline 18. A hopper 12 and a slag discharge box 16 are arranged inside the casing 9. The hopper 12 is used to store materials. A plurality of support plates are arranged on the inner wall of the hopper 12 for placing the air ring 22. An opening is arranged on one side of the hopper 12 below the air ring 22, and this opening communicates with the hot air inlet 11 on the casing 9. Hot air is introduced into the hot air inlet 11, and the hot air enters the mill through the opening on the inner wall of one side of the hopper 12 and moves upward to be ejected from the upper port of the air ring 22 to form a high-speed hot air flow. The high-speed hot air flow can dry the fine petroleum coke powder being ground while moving upward. The explosion-proof gas pipeline 18 is respectively connected to the powder separator 10 and the hot air inlet 11 to prevent coal powder from exploding in the mill. Refer to Figure 2 As shown, the slag discharge box 16 is located below the hot air inlet 11, and at the same time, the slag discharge box 16 communicates with the slag discharge port 28 at the bottom of the hopper 12. A scraper 27 is installed on the grinding table 7, and the scraper rotates with the grinding table 7. After the slag (also called difficult-to-grind materials, including: materials that are difficult to crush and metal blocks, and also including a small part of the petroleum coke raw material) falling from the air ring 22 enters the hopper 12, when the scraper 27 moves above the slag discharge box 16, it will scrape the slag into the slag discharge box 16 to prevent the slag from accumulating at the hot air inlet 11. Preferably, a pneumatic or hydraulic valve (also called a slag discharge valve) is arranged between the slag discharge box 16 and the hot air inlet 11. If a pneumatic valve is used, a corresponding air source device needs to be configured; if a hydraulic valve is used, a system can be set up in the vertical mill loading system for the hydraulic valve to use.

[0072] Refer to Figure 1As shown in the figure, the vertical mill further includes: a sealing system. The sealing system adopts a gas sealing method and includes: a sealing fan and a sealing air pipeline 17. The sealing fan is arranged according to the principle of being close to the equipment, and its position height can be flexibly set according to the actual on-site needs. The output end of the sealing fan (not shown in the figure) is connected to one end of the sealing air pipeline 17, and the other end of the sealing air pipeline 17 is communicated with the sealing air inlet of the roller assembly (specifically referring to the rocker arm 5). By introducing the sealing air along the sealing pipeline 17 into the sealing air inlet of each rocker arm 5 respectively, it can prevent powder impurities from entering the inside of the roller 6 and protect the normal operation of the roller 6 bearings. A flow regulating valve is provided at the sealing air inlet of the rocker arm 5, and the flow rate of the sealing air at the rocker arm 5 can be flexibly controlled through the flow regulating valve.

[0073] As an embodiment of the specific structure of the above loading system, in this embodiment, the loading system is connected to the roller assembly (referring to the rocker arm 5). While the roller 6 is rotating, the loading force output by the loading system acts on the roller 6 through the rocker arm 5, causing the roller 6 to extrude and grind the petroleum coke. During normal operation, the loading force provided by the loading system is 8 - 12 MPa. In this application, the loading system adopts a variable loading system and moves in a manner with a backup pressure in the rodless chamber. The loading system includes: a roll-over cylinder 21 and a tensioning cylinder 8. The two cylinders are respectively connected to the rocker arm 5 and are used to drive the roller 6 to act through the rocker arm 5. It should be noted that the rocker arm 6 is mainly composed of an upper rocker arm, a lower rocker arm, a rocker arm shaft, bearings, and a bearing seat, etc. The upper rocker arm is used to install the roller 6, and the lower rocker arm is connected to the loading system. The two rocker arms are connected into a whole through a shaft, a tapered sleeve, and a tapered pin. The bearing seat is installed on the bracket 4 and is used to install the shaft and bearings. When overhauling the roller 6, the tapered sleeve and tapered pin are removed, and the roll-over cylinder 21 is connected to the upper rocker arm. The roller 6 can be turned out of the mill for overhaul by flipping the upper rocker arm. After the main motor 2 is started, the position of the roller 6 changes due to the action of the petroleum coke on the mill table 7 on the roller 6, resulting in a change in the lifting pressure output by the tensioning cylinder 8. The tensioning cylinder 8 can lift the roller 6 to the specified position. Accumulators are provided in both the rodless chamber and the rod chamber of the two cylinders. During production, appropriately increase the specification of the cylinder size, and at the same time reduce the speed of the main reducer 3 by 20%. In this way, a greater loading force can be achieved, which can ensure that the roller 6 exhibits the best ultra-fine grinding effect and can make the product fineness reach more than 800 meshes.

[0074] Furthermore, the vertical mill further includes: a plurality of lubrication stations, such as a roller lubrication station, a main reducer lubrication station, and a glycerin lubrication station, which inject lubricating grease into each lubrication point in the vertical mill regularly and quantitatively to ensure the normal operation of the mechanism. The lubrication of the bearings of the roller 6 in this application adopts a forced lubrication technology, which uses a circulating system integrating filtration, lubrication, and cooling. The oil supply pump forcibly presses the lubricating oil to the bearing part, and the lubricating oil exceeding the set liquid level is forcibly recovered by the oil return pump, so that the lubricating liquid level of the roller 6 always remains constant, and the oil supply is sufficient and stable.

[0075] The working process of the vertical mill of the present application is as follows:

[0076] Start the seal fan, and lead the seal air through the seal air pipeline 17 to each rocker arm 5. Introduce explosion-proof gas into the mill, and the explosion-proof gas passes through the explosion-proof gas pipeline 18 to the separator 10 and the hot air inlet 11 respectively. Introduce the hot air into the interior of the mill from the hot air inlet 11. Start the main motor 2, and the main motor 2 drives the main speed reducer 3 to rotate through the coupling 20, and the grinding table 7 connected to the main speed reducer 3 also rotates accordingly. Add the petroleum coke raw material into the mill through the star-shaped discharger 25, and the petroleum coke raw material falls onto the center of the rotating grinding table 7 (specifically referring to the lining plate 701). The baffle ring 26 ensures that the petroleum coke raw material forms a certain thickness of material layer on the grinding table 7. Under the action of the loading system, lower the grinding roller 6. Under the action of centrifugal force, the petroleum coke raw material moves towards the edge of the grinding table 7. During the movement, the petroleum coke raw material will be crushed into particles under the rolling of the grinding roller 6. When the petroleum coke particles move to the edge of the grinding table 7, under the action of the high-speed hot air flow at the air ring 22, they leave the grinding table 7 and move upward. The larger particles directly fall onto the grinding table 7 for re-grinding, and the smaller particles follow the air flow to reach the separator 10. At the same time, start the separator 10. After being screened by the separator 10, the qualified petroleum coke fine powder goes out from the powder outlet of the separator 10 along with the air flow and is collected in the dust collection device of the mill. The unqualified fine powder falls back onto the grinding table 7 for continuous grinding. During the grinding of the petroleum coke, the water spraying system 13 continuously sprays water onto the surface of the grinding table 7 to stabilize the material layer. When the slag moves towards the edge of the grinding table 7 under the action of the centrifugal force of the rotation of the grinding table 7 until it is thrown out of the grinding table 7, and when the slag crosses the baffle ring 26 on the grinding table 7 and reaches the air ring 22, it is not sufficient to be blown up by the air flow ejected from the air ring 22, so it falls along the wind deflector 29 to the hopper 12 and is scraped to the slag discharge box 16 by the scraper 27 on the grinding table 7. Open and close the slag discharge valve above the slag discharge box 16 to facilitate the cleaning of the slag in the box.

[0077] As is known by common technical knowledge, the present utility model can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and are not exclusive. All changes within the scope of the present utility model or within the scope equivalent to the present utility model are encompassed by the present utility model.

Claims

1. A vertical mill for grinding petroleum coke, characterized in that: The vertical mill comprises: chassis; A grinding disc, the grinding disc is rotatably located in the housing; A grinding roller assembly, the grinding roller assembly is located in the housing above the grinding disc, the grinding roller assembly is in rolling contact with the grinding disc, and is used for grinding petroleum coke; A powder classifier, the powder classifier is located at the upper part of the casing and is used to screen the ground petroleum coke particles; The top edge of the grinding disc is detachably connected to a height-adjustable retaining ring assembly, the retaining ring assembly is composed of multiple layers of retaining rings, and the multiple layers of retaining rings are stacked on the top edge of the grinding disc; The retaining ring is fixed on the grinding disc by bolts.

2. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: Multiple layers of the retaining rings with different thicknesses are stacked on the top of the edge of the grinding disc.

3. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: The vertical mill also includes: a water spray system; The water spray system is installed in the casing and is used for spraying water toward the grinding disc.

4. The vertical mill for grinding petroleum coke according to claim 3, characterized in that: The water spray system comprises: a water pipe, a sealing plate, a guard plate and a windproof plate; One end of the water pipe is connected to a water source, and the other end of the water pipe penetrates into the housing above the grinding disc, and a plurality of water spray holes are arranged on the side wall of the water pipe; The sealing plate cover is arranged at the other end of the water delivery pipe; The windproof plate is located on the windward side of the water pipe; The guard plate is located on the leeward side of the water pipe, and the guard plate is connected to the windproof plate via a connecting piece.

5. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: The grinding roller assembly comprises: a grinding roller, a roller sleeve and a rocker arm; The plurality of grinding rollers are circumferentially distributed along the center line of the housing, the grinding rollers are located above the grinding disc, and the axes of the grinding rollers are arranged at an angle to the horizontal plane; The roller sleeve is sleeved on the outer side of the grinding roller; One end of the rocker arm is connected to the grinding roller, and the other end of the rocker arm is connected to the loading system.

6. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: The vertical mill also includes: an air ring, which includes: an inner ring, an outer ring and connecting blades; The inner ring is mounted on the grinding disc; The outer ring is sleeved on the circumferential outer side of the inner ring, and a cavity is formed between the outer ring and the inner ring, and the connecting blades are arranged in the cavity; The connecting blades are arranged at an angle, and the rotation direction of the connecting blades is consistent with the rotation direction of the stationary blades in the powder classifier.

7. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: The powder classifier comprises: moving blades, a rotor, a powder return cone, stationary blades and a variable frequency motor; A powder outlet is provided at the upper portion of the casing; One end of the central axis of the rotor passes through the top of the housing and is connected to the variable frequency motor; The plurality of moving blades are all located on the rotor; A plurality of the stationary blades are distributed along the circumference of the moving blades, the stationary blades are arranged at an angle with the horizontal plane, and one end of the stationary blades is connected to the top of the casing; One end of the powder return cone is connected to the other end of the stationary blade, and the other end of the powder return cone is connected to the discharger located outside the casing through a feed pipe; The powder return cone is 400 to 600 mm away from the conical manhole cover located at the center of the grinding disc.

8. The vertical mill for grinding petroleum coke according to claim 6, characterized in that: The vertical mill also includes: an explosion-proof gas pipeline; A hopper and a slag discharge box are arranged in the casing; A plurality of support plates are provided on the inner wall of the hopper for placing the air ring; An opening is provided on one side of the hopper below the air ring, and the opening is communicated with a hot air outlet on the casing; The explosion-proof gas pipeline is connected to the powder selector and the hot air outlet respectively; The slag discharge box is located below the hot air outlet, and the slag discharge box is connected to the slag discharge port at the bottom of the hopper for receiving slag.

9. The vertical mill for grinding petroleum coke according to claim 1, characterized in that: The vertical mill also includes: a sealing system; The sealing system comprises: a sealing fan and a sealing air duct; The output end of the sealed fan is connected to one end of the sealed air duct; The other end of the sealed air duct is communicated with the sealed air inlet of the grinding roller assembly; A flow regulating valve is provided at the sealing air inlet of the grinding roller assembly to control the flow of the sealing air.

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