High-carbon ferrochrome smelting raw material vertical mill equipment

Abstract

The present application belongs to the technical field of grinding equipment, and particularly relates to a high-carbon ferrochrome smelting raw material vertical grinding equipment, which comprises a vertical roller mill body, a material guide pipe is fixedly connected to a feeding port of the vertical roller mill body through bolts, and a treatment box is fixedly connected to a top end of the material guide pipe. The high-carbon ferrochrome smelting raw material vertical grinding equipment has the functions of pre-crushing and uniform particle, laser online moisture measurement, dynamic hot air drying and waste heat recovery, can effectively solve the industry common problems such as unstable operation of the vertical grinding, high abrasion, low grinding efficiency, out-of-control finished product indexes and the like caused by mixed chromium ore blocks and powder and fluctuation of water content, and through cooperation of multiple mechanisms, the stability, automation level and grinding efficiency of the chromium ore raw material vertical grinding are greatly improved, the operation and maintenance cost, grinding and smelting comprehensive energy consumption are significantly reduced, the reliability and effect of the vertical grinding equipment are improved, and thus the grinding finished product quality can be stably ensured for a long time, and reliable support is provided for smooth high-carbon ferrochrome smelting.

Description

Technical Field

[0001] This invention belongs to the technical field of grinding equipment, and in particular relates to a vertical mill for high-carbon ferrochrome smelting raw materials. Background Technology

[0002] High-carbon ferrochrome is a ferrochrome alloy with a carbon content of ≥4%. It is a core raw material for the production of stainless steel and special alloy steel and is widely used in the metallurgical industry. Chromium ore is the core raw material for high-carbon ferrochrome smelting. To ensure the uniformity of the furnace charge, the efficiency of the reduction reaction, and the stability of the smelting conditions, the chromium ore raw material needs to be ground to the target particle size distribution. Vertical roller mills, with their integrated advantages of grinding, drying, and powder selection, and their high grinding efficiency and small footprint, are currently the mainstream core equipment for chromium ore grinding in the industry.

[0003] Currently, chromite raw materials in the industry are mostly pre-crushed by crushers before entering the mill. However, the particle size distribution of the chromite raw materials after crushing is extremely uneven, and the problem of mixed lumps and powders is still quite prominent, making it impossible to form a uniform and stable material bed on the grinding disc of a vertical roller mill. In particular, large pieces of hard chromite raw materials can easily cause high-frequency vibration of the grinding rollers, excessive equipment vibration, and frequent triggering of interlock shutdowns. At the same time, it can significantly aggravate the impact wear of the grinding rollers and grinding disc liners. Furthermore, insufficient single-pass crushing of large pieces of chromite raw materials can lead to a surge in the internal circulation volume of the vertical roller mill, a significant decrease in grinding efficiency, and persistently high unit power consumption.

[0004] Meanwhile, due to the influence of mining and open-air storage environments, the moisture content of chromium ore is prone to exceed the standard and fluctuates greatly. The existing pretreatment process lacks a corresponding online humidity control link. When high-moisture chromium ore raw materials are put into the mill and subjected to pressure, water is released, and fine powder agglomerates and forms lumps, which can easily cause skin formation inside the mill, blockage of air ducts, slippage of the material bed, and a significant decrease in grinding efficiency, ultimately leading to the loss of control over the indicators of the chromium ore ground product. When unqualified chromium ore ground product is put into the furnace, it will cause fluctuations in furnace conditions, which in turn will lead to unstable grades of high-carbon ferrochrome products and increased smelting energy consumption.

[0005] Therefore, we propose a vertical mill for high-carbon ferrochrome smelting raw materials to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the above-mentioned problems by providing a vertical mill for high-carbon ferrochrome smelting raw materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a vertical mill equipment for high-carbon ferrochrome smelting raw materials, comprising a vertical roller mill body, wherein the feed inlet of the vertical roller mill body is fixedly connected to a guide pipe by bolts, a processing box is fixedly connected to the top end of the guide pipe, the discharge hole of the processing box is located inside the top opening of the guide pipe, a box cover is fixedly connected to the top opening of the processing box by bolts, a through hole is opened at the top end of the box cover, and a feed hopper is fixedly connected to the wall of the through hole; The inner wall of the processing box is fixedly connected to a raw material pretreatment mechanism; The outer wall of the processing box is fixedly connected to a transmission mechanism for driving the raw material pretreatment mechanism; The inner wall of the processing box is fixedly connected to a raw material humidity control mechanism; The inner wall of the feed pipe is fixedly connected to a hot air reuse mechanism that works in conjunction with the raw material humidity control mechanism. A raw material moisture measuring mechanism is fixedly connected to the inner wall of the top of the feed hopper; A material guiding mechanism is fixedly connected to the bottom inner wall of the processing box.

[0008] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the raw material pretreatment mechanism includes two pressure rollers, both ends of which are fixedly fitted with sealed bearings. The outer wall of the treatment box is provided with multiple fixed through holes that cooperate with the outer wall of the outer ring of the sealed bearings. The outer wall of the pressure rollers is fixedly connected with six evenly distributed arc-shaped wear-resistant inner lining plates by bolts. The outer walls of both ends of the arc-shaped wear-resistant inner lining plates are in sliding contact with the inner wall of the treatment box.

[0009] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the transmission mechanism includes a U-shaped frame and a PLC controller fixedly connected to the outer wall of the processing box. A geared motor is fixedly connected to the outer wall of the U-shaped frame. The output end of the geared motor is fixedly connected to the side end of one of the pressure rollers through a safety coupling. Both pressure rollers are fixedly sleeved with transmission gears near the side ends of the U-shaped frame, and the two transmission gears mesh with each other.

[0010] In the aforementioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the raw material humidity control mechanism includes a heat insulation cylinder and an air pump fixedly connected to the inner wall of the processing chamber. The top of the heat insulation cylinder has a through hole, and an electric heating tube is fixedly connected to the wall of the through hole. Multiple annular metal mesh sheets are fixedly sleeved on the heating section wall of the electric heating tube. A bent pipe is fixedly connected to the outlet end of the air pump. The outlet end of the bent pipe is fixedly connected to the bottom cavity of the heat insulation cylinder. A heat insulation pipe is fixedly connected to the top cavity of the heat insulation cylinder. A hollow ring is fixedly sleeved on the outer wall of the feed hopper. The outlet end of the heat insulation pipe passes through the chamber. The upper surface of the cover is fixedly connected to the internal cavity of the hollow ring. The inner wall of the hollow ring has multiple through holes, and the walls of the through holes are fixedly connected to multiple branch pipes. The air outlet of the branch pipes is fixedly connected to the inner wall of the feed hopper. The outer wall of the hollow ring is fixedly connected to a fixing frame. The outer wall of the fixing frame is fixedly connected to a temperature sensor by a nut. The outer wall of the hollow ring has an insertion hole that matches the detection end of the temperature sensor. The detection end of the temperature sensor is located inside the annular cavity of the hollow ring. The rod wall of the temperature sensor is fixedly sleeved with a sealing ring that matches the inner wall of the insertion hole.

[0011] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the hot air reuse mechanism includes a rubber strip and a hollow buffer block fixedly connected to the inner wall of the feed pipe. An arc-shaped fine mesh filter plate is fixedly connected to the outer wall of the rubber strip and the hollow buffer block. Rubber sheets are fixedly connected to both sides of the arc-shaped fine mesh filter plate. The two ends of the rubber strip and the hollow buffer block are fixedly connected to the surfaces of the two rubber sheets respectively. The bottom end of the rubber sheet is fixedly connected to the inner wall of the feed pipe. An arc-shaped pipe is fixedly connected to the outer wall of the feed pipe located inside the arc-shaped fine mesh filter plate. The top end of the arc-shaped pipe is fixedly connected to the bottom cavity of the processing box.

[0012] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the raw material humidity measuring mechanism includes an L-shaped baffle plate fixedly connected to the inner wall of the feed hopper. A fixed through hole is opened on the upper surface of the horizontal part of the L-shaped baffle plate, and a laser humidity sensor is fixedly connected to the wall of the fixed through hole. A hollow metal block is fixedly connected to the lower surface of the horizontal part of the L-shaped baffle plate. An air outlet is opened on the outer wall of the hollow metal block near the laser humidity sensor. A metal tube is fixedly connected to the tube wall of the hollow metal block, and the bottom end of the metal tube is fixedly connected to the inner wall of the hollow ring.

[0013] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, the material guiding mechanism includes two inclined plates that are fixedly connected to the inner wall of the bottom of the processing box. Scrapers are fixedly connected to the opposite side of the two inclined plates. The tops of the scrapers and the inclined plates are in contact with the outer wall of the arc-shaped wear-resistant inner liner. Partitions are fixedly connected to the opposite side of the two inclined plates. The side walls of the partitions are fixedly connected to the inner wall of the processing box. One of the partitions has a through hole on its upper surface that matches the outer wall of the heat insulation cylinder. The air pump is located below the partition. The two partitions divide the internal cavity of the processing box into an open area and a sealed area. Two inclined guide strips are fixedly connected to the lower surface of the box cover. The bottom ends of the guide strips are in contact with the outer wall of the arc-shaped wear-resistant inner liner. Two inclined and symmetrically arranged arc-shaped guide plates are fixedly connected to the opposite side of the two inclined plates.

[0014] In the above-mentioned vertical mill equipment for high-carbon ferrochrome smelting raw materials, two symmetrically distributed support columns are fixedly connected to the lower surface of the processing box, and a fixed square plate is fixedly connected to the bottom end of the support columns.

[0015] Compared with existing technologies, the advantages of a vertical mill for high-carbon ferrochrome smelting raw materials are: 1. Through the set raw material pretreatment mechanism, transmission mechanism and guiding mechanism, when the pre-crushed chromite raw material enters the processing box, the vertical mill equipment drives two pressure rollers to rotate synchronously in opposite directions through the transmission mechanism. With the help of the arc-shaped wear-resistant inner lining plate on the outer wall of the pressure roller, the chromite raw material is squeezed, pre-crushed and uniformly sized. This solves the problems of vertical mill bed instability, grinding roller jumping, vibration and excessive noise caused by the mixing of chromite lumps and powder and large particle size fluctuations in the existing technology. The scraper of the guiding mechanism can clean the material sticking to the roller in real time, ensuring stable pre-crushing effect, greatly reducing the impact wear of the vertical mill wear parts, reducing unplanned downtime and improving the grinding efficiency of the vertical mill.

[0016] 2. Through the set raw material humidity measurement mechanism, raw material humidity control mechanism and PLC controller, when the chromite raw material enters the feed hopper, the vertical mill equipment collects the initial moisture content data of the incoming material in real time through the laser humidity sensor. The PLC controller compares the detection data with the preset threshold, and uses inverse proportional logic to control the speed of the pressure roller and direct proportional logic to control the hot air parameters, forming a fully automatic closed-loop control. This solves the problems of excessive fluctuation of chromite moisture content, mill internal scaling and blockage, material bed slippage and uncontrolled finished product indicators caused by the lack of online humidity control in the existing technology. It stabilizes the moisture content of chromite raw material from the source of feed, ensures the stable operation of the subsequent chromite raw material grinding process, improves the grinding efficiency of chromite raw material and the quality of finished product, and ensures the reliability of equipment operation.

[0017] 3. Through the hot air reuse mechanism, when the vertical roller mill is running, the hot air carrying the waste heat from the vertical roller mill body enters the feed pipe, is filtered by the arc-shaped fine mesh filter plate, and flows back to the sealed area of ​​the treatment box for recycling through the arc pipe. Moreover, the impact of the pre-treated chromite raw material falling causes the filter plate to vibrate flexibly, which can avoid filter hole blockage, ensure smooth hot air circulation, make full use of waste heat to reduce the power consumption of electric heating tubes, and significantly improve the energy-saving performance of the vertical roller mill.

[0018] 4. Through the connection structure between the feed hopper, guide pipe and processing box, as well as the L-shaped baffle and purging protection structure of the raw material humidity measuring mechanism, when the vertical roller mill is running, the suction structure of the vertical roller mill body creates a stable negative pressure between the feed hopper and the processing box, which solves the problem of dust easily scattering and polluting during the feeding process. The L-shaped baffle can prevent material impact from damaging the laser humidity sensor. Combined with the continuous purging of the detection end face by the drying airflow, it ensures long-term stable detection accuracy and improves the environmental performance and operational reliability of the vertical roller mill.

[0019] 5. Through the linkage structure of the set temperature sensor, PLC controller and each actuator, when the vertical mill is running, the temperature sensor collects the hot air temperature data in real time and feeds it back to the PLC controller. The PLC controller can adjust the heating power in real time to ensure that the hot air temperature is in the optimal range. This greatly improves the control accuracy of the raw material humidity control mechanism and the raw material pretreatment mechanism during the operation of the vertical mill. It not only improves the humidity of chromite raw materials and the convenience of pretreatment, but also greatly improves the automation level and operational stability of the vertical mill and reduces the intensity of personnel operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a vertical mill for high-carbon ferrochrome smelting raw materials provided by the present invention; Figure 2 This is a side view of the structure of a vertical mill for high-carbon ferrochrome smelting raw materials provided by the present invention; Figure 3 This is the present invention. Figure 2 A schematic diagram of the structure in partial cross-section; Figure 4 This is the present invention. Figure 3 A magnified structural diagram of the medium temperature sensor section; Figure 5 This is the present invention. Figure 3 Enlarged structural schematic diagram of the hot air recycling mechanism; Figure 6 This is the present invention. Figure 3 Enlarged structural schematic diagram of the raw material moisture measuring mechanism; Figure 7 This is a partial top view of the material guiding mechanism in a vertical mill for high-carbon ferrochrome smelting raw materials provided by the present invention; Figure 8 This is a three-dimensional structural diagram of the raw material pretreatment mechanism in a vertical mill for high-carbon ferrochrome smelting provided by the present invention; Figure 9 This is a three-dimensional structural diagram of the transmission mechanism in a vertical mill for high-carbon ferrochrome smelting raw materials provided by the present invention.

[0021] In the diagram: 1 Vertical roller mill body, 2 Feed pipe, 3 Processing box, 4 Raw material pretreatment mechanism, 41 Pressure roller, 42 Sealed bearing, 43 Arc-shaped wear-resistant inner liner, 5 Transmission mechanism, 51 U-shaped frame, 52 PLC controller, 53 Gear motor, 54 Transmission gear, 6 Raw material humidity control mechanism, 61 Heat insulation cylinder, 62 Air pump, 63 Electric heating tube, 64 Annular metal mesh, 65 Bend, 66 Heat insulation tube, 67 Hollow ring, 68 Branch pipe, 69 Fixing frame, 610 Temperature sensor, 611 7. Sealing ring, 7. Hot air reuse mechanism, 71. Rubber strip, 72. Hollow buffer block, 73. Arc-shaped fine filter plate, 74. Rubber sheet, 75. Arc-shaped tube, 8. Raw material humidity measuring mechanism, 81. L-shaped baffle plate, 82. Laser humidity sensor, 83. Hollow metal block, 84. Air outlet, 85. Metal tube, 9. Material guiding mechanism, 91. Inclined plate, 92. Scraper, 93. Partition plate, 94. Open area, 95. Sealed area, 96. Material guiding strip, 97. Arc-shaped material guiding plate, 10. Box cover, 11. Feed hopper, 12. Support column, 13. Fixed square plate. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1-9 As shown, a vertical roller mill for high-carbon ferrochrome smelting raw materials includes a vertical roller mill body 1. The feed inlet of the vertical roller mill body 1 is fixedly connected to a guide pipe 2 by bolts. The top end of the guide pipe 2 is fixedly connected to a processing box 3. The discharge hole of the processing box 3 is located inside the top opening of the guide pipe 2. The top opening of the processing box 3 is fixedly connected to a box cover 10 by bolts. The top end of the box cover 10 has a through hole, and the wall of the through hole is fixedly connected to a feed hopper 11. The lower surface of the processing box 3 is fixedly connected to two symmetrically distributed support columns 12. The bottom end of the support columns 12 is fixedly connected to a fixed square plate 13.

[0024] The inner wall of the processing box 3 is fixedly connected to a raw material pretreatment mechanism 4, which includes two pressure rollers 41. Both shaft ends of the pressure rollers 41 are fixedly sleeved with sealed bearings 42. The outer wall of the processing box 3 is provided with multiple fixed through holes that cooperate with the outer ring of the sealed bearings 42. The outer wall of the pressure rollers 41 is fixedly connected with six evenly distributed arc-shaped wear-resistant inner lining plates 43 by bolts. The outer walls of both ends of the arc-shaped wear-resistant inner lining plates 43 are in sliding contact with the inner wall of the processing box 3.

[0025] The outer wall of the processing box 3 is fixedly connected to a transmission mechanism 5 for driving the raw material pretreatment mechanism 4. The transmission mechanism 5 includes a U-shaped frame 51 and a PLC controller 52 fixedly connected to the outer wall of the processing box 3. A geared motor 53 is fixedly connected to the outer wall of the U-shaped frame 51. The output end of the geared motor 53 is fixedly connected to the side end of one of the pressure rollers 41 through a safety coupling. The safety coupling has an overload protection function, which improves the protection capability of the transmission mechanism 5 and improves the reliability of the vertical mill equipment. The two pressure rollers 41 are fixedly sleeved with transmission gears 54 near the side end of the U-shaped frame 51. The two transmission gears 54 mesh with each other.

[0026] A raw material humidity control mechanism 6 is fixedly connected to the inner wall of the processing box 3. The raw material humidity control mechanism 6 includes a heat insulation cylinder 61 and an air pump 62 fixedly connected to the inner wall of the processing box 3. The top of the heat insulation cylinder 61 has a through hole, and an electric heating tube 63 is fixedly connected to the wall of the through hole. Multiple annular metal meshes 64 are fixedly sleeved on the heating section wall of the electric heating tube 63. The annular metal meshes 64 are used to increase the heat exchange area of ​​the hot air, uniform airflow, and prevent uneven drying caused by hot air deviation. The air outlet of the air pump 62 is fixedly connected to a bend pipe 65. The air outlet of the bend pipe 65 is fixedly connected to the bottom cavity of the heat insulation cylinder 61. The top cavity of the heat insulation cylinder 61 is fixedly connected to a heat insulation pipe 66. A hollow core is fixedly sleeved on the outer wall of the feed hopper 11. The air outlet of the heat insulation pipe 66 passes through the upper surface of the cover 10 and is fixedly connected to the internal cavity of the hollow ring 67. The inner wall of the hollow ring 67 has multiple through holes, and multiple branch pipes 68 are fixedly connected to the wall of the through holes. The air outlet of the branch pipes 68 is fixedly connected to the inner wall of the feed hopper 11. The outer wall of the hollow ring 67 is fixedly connected to a fixing frame 69. The outer wall of the fixing frame 69 is fixedly connected to a temperature sensor 610 by a nut. The outer wall of the hollow ring 67 has an insertion hole that matches the detection end of the temperature sensor 610. The detection end of the temperature sensor 610 is located inside the annular cavity of the hollow ring 67. The rod wall of the temperature sensor 610 is fixedly sleeved with a sealing ring 611 that matches the inner wall of the insertion hole.

[0027] A hot air recycling mechanism 7, which works in conjunction with the raw material humidity control mechanism 6, is fixedly connected to the inner wall of the feed pipe 2. The hot air recycling mechanism 7 includes a rubber strip 71 and a hollow buffer block 72 fixedly connected to the inner wall of the feed pipe 2. An arc-shaped fine mesh filter plate 73 is fixedly connected to the outer wall of the rubber strip 71 and the hollow buffer block 72. The arc-shaped fine mesh filter plate 73 is made of 180-220 mesh high-temperature resistant 310S stainless steel sintered mesh, with a rated filtration accuracy of 75-85μm. Both sides of the arc-shaped fine mesh filter plate 73 are fixedly connected to... The two ends of the rubber sheet 74, rubber strip 71 and hollow buffer block 72 are fixedly connected to the surface of the two rubber sheets 74 respectively. The bottom end of the rubber sheet 74 is fixedly connected to the inner wall of the guide pipe 2. The outer wall of the guide pipe 2 located inside the arc-shaped fine filter plate 73 is fixedly connected to the arc-shaped pipe 75. The top end of the arc-shaped pipe 75 is fixedly connected to the bottom cavity of the processing box 3. This mechanism achieves hot air dust interception through rated precision filtration, and achieves self-cleaning by material impact and shaking, ensuring smooth hot air circulation and protection of core components.

[0028] A raw material humidity measuring mechanism 8 is fixedly connected to the inner wall of the top of the feed hopper 11. The raw material humidity measuring mechanism 8 includes an L-shaped baffle plate 81 fixedly connected to the inner wall of the feed hopper 11. A fixed through hole is opened on the upper surface of the horizontal part of the L-shaped baffle plate 81, and a laser humidity sensor 82 is fixedly connected to the wall of the fixed through hole. A hollow metal block 83 is fixedly connected to the lower surface of the horizontal part of the L-shaped baffle plate 81. An air outlet 84 is opened on the outer wall of the hollow metal block 83 near the laser humidity sensor 82. A metal tube 85 is fixedly connected to the tube wall of the hollow metal block 83. The bottom end of the metal tube 85 is fixedly connected to the inner wall of the hollow ring 67.

[0029] A material guiding mechanism 9 is fixedly connected to the inner wall of the bottom end of the processing box 3. The material guiding mechanism 9 includes two inclined plates 91 that are fixedly connected to the inner wall of the bottom end of the processing box 3. A scraper 92 is fixedly connected to one side of each of the two inclined plates 91. The scraper 92 is made of bimetallic composite wear-resistant steel plate with a base plate and a high-chromium alloy wear-resistant layer. The wear-resistant layer of its scraping edge has a hardness of HRC≥62. The high-chromium alloy wear-resistant layer ensures the wear resistance of the scraping edge, which can continuously scrape off the material adhering to the surface of the arc-shaped wear-resistant inner liner plate 43 while avoiding adhesion caused by rapid wear of the cutting edge. To address issues such as increased gaps and failure of material removal, and to ensure the continuous and stable surface cleanliness and pre-crushing effect of the pressure roller 41, the tops of the scraper 92 and the inclined plate 91 are in contact with the outer wall of the arc-shaped wear-resistant inner liner 43. A partition 93 is fixedly connected to the opposite side of each of the two inclined plates 91. The side wall of the partition 93 is fixedly connected to the inner wall of the processing box 3. One of the partitions 93 has a through hole on its upper surface that matches the outer wall of the heat insulation cylinder 61. The air pump 62 is located below the partition 93. The two partitions 93 divide the internal cavity of the processing box 3 into an open area 94 and... The air inlet of the vacuum pump 62 is connected to the cavity of the sealed area 95. Two inclined guide bars 96 are fixedly connected to the lower surface of the box cover 10. The bottom contact surface of the guide bars 96 is overlaid with a D707 tungsten carbide wear-resistant alloy layer with a thickness of ≥3mm and a hardness of HRC≥60. This layer can effectively resist continuous sliding friction with the rotating arc-shaped wear-resistant inner liner 43, avoid material guiding failure and large material escape caused by rapid wear of the guide bars 96, and ensure that the chromium ore raw material falls accurately into the crushing zone of the double pressure rollers 41. The guide bar 96 has a stable pre-crushing and uniform particle size distribution. The bottom end of the guide bar 96 contacts the outer wall of the arc-shaped wear-resistant inner liner 43. Two inclined plates 91 are fixedly connected to two inclined and symmetrically arranged arc-shaped guide plates 97 on the opposite side. The arc-shaped wear-resistant inner liner 43 is made of KmTBCr26 high-chromium alloy cast iron. After overall quenching, the hardness is HRC≥58, which has excellent impact and wear resistance. It can be adapted to the continuous extrusion crushing conditions of hard chromium ore materials. Moreover, the guide mechanism 9 can be replaced regularly to ensure the reliability of continuous use of the vertical mill equipment.

[0030] The geared motor 53, the air pump 62, and the electric heating element 63 are all electrically connected to the output terminal of the PLC controller 52 via wires. The temperature sensor 610 and the laser humidity sensor 82 are all electrically connected to the input terminal of the PLC controller 52 via wires. The above electrical components and electrical connections are existing technologies and will not be described in detail here.

[0031] The operating principle of the present invention is described as follows: Before the vertical mill equipment performs grinding operations on high-carbon ferrochrome smelting raw materials, the system initialization settings are first completed by the PLC controller 52, which presets the optimal moisture content of the chromium ore raw material entering the mill, the hot air working temperature, and the basic operating parameter thresholds of the pressure roller 41. Then, the PLC controller 52 controls the start of the reduction motor 53, the vertical roller mill body 1, the air pump 62, and the electric heating tube 63. The reduction motor 53 drives one side of the pressure roller 41 to rotate, and drives the other pressure roller 41 to rotate synchronously in opposite directions through the meshing transmission gear 54. The air pump 62 continuously sends air into the heat insulation cylinder 61 through the bend pipe 65. After the airflow is heated by the electric heating tube 63, it forms dry hot air. The hot air is delivered to the hollow ring 67 through the heat insulation pipe 66, completing the pre-start preparation of the vertical mill equipment before operation.

[0032] Next, the chromite raw material, which has been initially crushed by the crusher, is conveyed to the feed hopper 11 by the conveying equipment. As the chromite raw material falls along the inner wall of the feed hopper 11, it is blocked and limited by the L-shaped baffle 81, so it will not directly hit the laser humidity sensor 82. This can avoid damage to the laser humidity sensor 82 by the impact of the chromite raw material and ensure the reliability of the detection data. The laser humidity sensor 82 emits a near-infrared detection laser beam of a specific wavelength vertically downward. By utilizing the characteristic absorption characteristics of water molecules on this wavelength of laser, the sensor captures the light intensity attenuation signal of the laser beam reflected by the chromite raw material and quickly calculates the real-time initial moisture content data of the falling chromite raw material through an internal algorithm. The detection data is then transmitted to the PLC controller 52 in real time. The PLC controller 52 compares the detection data with the preset optimal moisture content threshold. When the moisture content of the chromite raw material is detected to be higher than the preset threshold, it indicates that the chromite raw material is relatively damp. Then, the PLC controller 52 uses inverse proportional control logic to reduce the output speed of the geared motor 53. Through the transmission gear 54, the opposing rotation speed of the two pressure rollers 41 is reduced synchronously, so that the residence time of the chromite raw material in the processing box 3 is effectively extended. At the same time, the PLC controller 52 uses direct proportional control logic to synchronously increase the heating power of the electric heating tube 63 and the air flow of the air pump 62, extend the drying residence time of the chromite raw material, improve the drying capacity, improve the drying effect of the vertical mill equipment on damp chromite raw material, avoid the situation where the damp chromite raw material precipitates moisture at the grinding disc of the vertical roller mill body 1, which leads to the agglomeration of chromite fine powder, and ensure that the vertical roller mill body 1 can operate continuously and stably. When the moisture content of the raw material is detected to be within the preset threshold, it indicates that the chromite raw material is relatively dry. Then, the PLC controller 52 increases the output speed of the geared motor 53 to improve the processing efficiency of the chromite raw material. At the same time, it simultaneously reduces the heating power of the electric heating tube 63 and the air flow of the vacuum pump 62 to reduce ineffective energy consumption. Under different incoming material moisture content conditions, it always takes into account both drying effect and processing efficiency, forming a fully automatic closed-loop dynamic balance of chromite raw material moisture detection, control and feedback. This effectively solves the industry pain point of excessive and large fluctuations in chromite raw material moisture content. It effectively controls the fluctuation of chromite raw material moisture content from the source of feeding and greatly reduces the adverse effects of high moisture raw materials on subsequent grinding processes.

[0033] Afterwards, the dry hot air inside the hollow ring 67 is evenly fed into the feed hopper 11 through multiple sets of branch pipes 68 to dry the chromium ore raw material with hot air, thus removing free water from the raw material in advance. At the same time, part of the hot air inside the hollow ring 67 is transported to the hollow metal block 83 through the metal pipe 85. The hot air in this branch is cooled down after heat exchange between the metal pipe 85 and the hollow metal block 83, preventing high-temperature air from damaging the laser humidity sensor 82. Specifically, the metal pipe 85 and the hollow metal block 83 are made of thermally conductive metal, and the cooling is achieved through natural heat exchange with the ambient temperature environment at the feed hopper 11, ensuring the safety of the optical components inside the laser humidity sensor 82. The cooled dry air is continuously blown out to the detection end face of the laser humidity sensor 82 through the air outlet 84, blowing away the fine dust adhering to the detection end face in real time, preventing dust from obstructing the detection accuracy, and ensuring that the humidity detection data is stable, accurate and reliable in the long term.

[0034] The pre-dried chromium ore raw material continues to fall along the feed hopper 11, and is precisely guided by the guide strip 96 on the lower surface of the cover 10 to the extrusion area between the two pressure rollers 41. The two pressure rollers 41, whose speeds are controlled by the PLC controller 52, rotate synchronously in opposite directions. Through the arc-shaped wear-resistant inner liner 43 on the outer wall, the chromium ore raw material is continuously and uniformly extruded and crushed. This further homogenizes and crushes the raw material, which still has uneven particle size distribution and is mixed with lumps and powder after the initial crushing, to a narrow particle size range that meets the requirements of vertical mill input. In addition, the arc-shaped inner liner 43 is periodically repaired and ground. The wear-resistant inner liner plate 43 ensures the stability of the gap between the pressure rollers 41, ensuring that the double pressure rollers 41 can crush chromite raw materials in a stable and uniform manner over a long period of time. This specifically addresses the problems of high proportion of large chromite raw materials and large particle size fluctuations. At the same time, the scraper 92 at the top of the inclined plate 91 continuously contacts the outer wall of the arc-shaped wear-resistant inner liner plate 43. During the rotation of the pressure rollers 41, the scraper 92 promptly removes the chromite raw materials adhering to the surface of the arc-shaped wear-resistant inner liner plate 43, avoiding the reduction in crushing effect caused by the chromite raw materials sticking to the rollers, and ensuring the continuous and stable operation of the pre-crushing process.

[0035] After being extruded, homogenized, and crushed, the chromite raw material is precisely guided and converged by the guiding mechanism 9, which consists of inclined plate 91 and arc-shaped guide plate 97, and smoothly falls into the guide pipe 2 below. Finally, it is stably fed into the grinding area of ​​the vertical roller mill body 1 through the guide pipe 2 to complete the final grinding operation. The pre-treated chromite raw material has uniform particle size and stable moisture content. After entering the grinding disc of the vertical roller mill body 1, it can form a stable material bed with uniform thickness and dense structure. This effectively avoids the problems of high-frequency jumping of grinding rollers, equipment vibration, and excessive noise caused by large hard raw materials, greatly reduces the impact wear of grinding rollers and grinding disc liners, reduces the downtime risk of the vertical roller mill body 1, and reduces the amount of unqualified chromite raw material in the vertical roller mill body 1. The increased circulation volume significantly improves the grinding speed of chromite raw materials, reduces unit grinding power consumption, and greatly alleviates problems such as water separation, fine powder adhesion and agglomeration causing mill internal scaling, air duct blockage, and material bed slippage after high-moisture raw materials enter the mill. It ensures the stability of particle size and moisture content of the chromite grinding product, effectively avoids furnace condition fluctuations, unstable high-carbon ferrochrome product grade, and increased smelting energy consumption caused by unqualified powder entering the furnace, thereby improving the operational stability and grinding efficiency of the vertical mill equipment. At the same time, it significantly reduces equipment maintenance costs, operating noise and overall energy consumption, and ensures the stable quality of the chromite grinding product, providing reliable support for the smooth operation of subsequent high-carbon ferrochrome smelting processes. It has strong practicality and industry promotion value.

[0036] During operation, the suction structure inside the vertical roller mill body 1 is connected to the inside of the processing box 3 through the guide pipe 2, so that the processing box 3 and the inside of the feed hopper 11 form a stable negative pressure environment. On the one hand, the pre-treated chromite raw material can smoothly enter the vertical roller mill body 1 through the guide pipe 2, improving the conveying efficiency of chromite raw material. On the other hand, it effectively prevents the fine chromite powder from drifting into the external environment from the top opening of the feed hopper 11 during the feeding process, reducing dust leakage pollution on site, improving the working environment of operators, and improving the environmental performance of the vertical roller mill equipment.

[0037] Meanwhile, the hot air carrying residual heat inside the vertical roller mill body 1 is conveyed into the feed pipe 2 along with the chromite raw material. After being filtered by the arc-shaped fine mesh filter plate 73, the hot air flows back to the sealed area 95 of the processing box 3 through the arc-shaped pipe 75. The arc-shaped fine mesh filter plate 73 can intercept hard chromite fine powder, effectively preventing the chromite fine powder carried in the hot air from entering the arc-shaped pipe 75, avoiding wear, scaling, and blockage problems in subsequent pipelines, impeller of air pump 62, and electric heating tube 63. This filtration precision takes into account both the hot air flow area and system air resistance, and combined with the continuous shaking self-cleaning effect formed by the impact of falling materials, it ensures the raw material humidity control mechanism. 6. Long-term stable operation; During the fall of the pre-treated raw material, it will continuously impact the arc-shaped fine filter plate 73. The arc-shaped fine filter plate 73 will continuously shake under the flexible cooperation of the rubber strip 71, hollow buffer block 72 and rubber sheet 74, which can shake off the fine raw material adhering to the surface of the arc-shaped fine filter plate 73 in time, avoid filter hole blockage, ensure smooth hot air circulation, and return the hot air with residual heat to the sealing area 95. The hot air is then drawn again by the air pump 62 and sent into the heat insulation cylinder 61 for circulation heating, making full use of the residual heat of the hot air, effectively reducing the heating power consumption of the electric heating tube 63, and improving the energy-saving performance of the vertical mill equipment.

[0038] During operation, the temperature sensor 610 collects the hot air temperature data inside the hollow ring 67 in real time and transmits the data to the PLC controller 52. The PLC controller 52 adjusts the heating power of the electric heating tube 63 in real time according to the temperature detection data to ensure that the hot air temperature is always within the preset optimal drying range. This avoids excessive drying of raw materials and a surge in dust due to excessively high hot air temperature, or insufficient drying effect due to excessively low temperature, further improving the stability and control accuracy of the vertical mill. At the same time, the PLC controller 52 can synchronously receive the operating status signal of the vertical roller mill body 1, realizing the synchronous start-stop and linkage control of the chromite raw material pretreatment structure and the vertical roller mill body 1, greatly improving the ease of operation and automation level of the vertical mill and reducing the intensity of personnel operation.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A vertical mill for high-carbon ferrochrome smelting raw materials, comprising a vertical roller mill body (1), characterized in that, The feed inlet of the vertical roller mill body (1) is fixedly connected to a guide pipe (2) by bolts. The top end of the guide pipe (2) is fixedly connected to a processing box (3). The discharge hole of the processing box (3) is located inside the top opening of the guide pipe (2). The top opening of the processing box (3) is fixedly connected to a box cover (10) by bolts. The top end of the box cover (10) has a through hole, and the wall of the through hole is fixedly connected to a feed hopper (11). The inner wall of the processing box (3) is fixedly connected to a raw material pretreatment mechanism (4); The outer wall of the processing box (3) is fixedly connected to a transmission mechanism (5) for driving the raw material pretreatment mechanism (4). The inner wall of the processing box (3) is fixedly connected to a raw material humidity control mechanism (6). The inner wall of the feed pipe (2) is fixedly connected to a hot air reuse mechanism (7) that works with the raw material humidity control mechanism (6); The top inner wall of the feed hopper (11) is fixedly connected to a raw material moisture measuring mechanism (8). The bottom inner wall of the processing box (3) is fixedly connected to a material guiding mechanism (9); The raw material pretreatment mechanism (4) includes two pressure rollers (41). Both ends of the pressure rollers (41) are fixedly fitted with sealed bearings (42). The outer wall of the treatment box (3) is provided with multiple fixed through holes that cooperate with the outer wall of the outer ring of the sealed bearings (42). The outer wall of the pressure rollers (41) is fixedly connected with six evenly distributed arc-shaped wear-resistant inner lining plates (43) by bolts. The outer walls of both ends of the arc-shaped wear-resistant inner lining plates (43) are in sliding contact with the inner wall of the treatment box (3). The raw material humidity control mechanism (6) includes a heat insulation cylinder (61) and a vacuum pump (62) fixedly connected to the inner wall of the processing box (3). The top of the heat insulation cylinder (61) has a through hole, and an electric heating tube (63) is fixedly connected to the wall of the through hole. Multiple annular metal meshes (64) are fixedly sleeved on the heating section wall of the electric heating tube (63). The outlet end of the vacuum pump (62) is fixedly connected to a bent pipe (65). The outlet end of the bent pipe (65) is fixedly connected to the bottom cavity of the heat insulation cylinder (61). The top cavity of the heat insulation cylinder (61) is fixedly connected to a heat insulation tube (66). A hollow ring (67) is fixedly sleeved on the outer wall of the feed hopper (11). The outlet end of the heat insulation tube (66) passes through the upper surface of the box cover (10) and is connected to... The hollow ring (67) has a fixed internal cavity that is connected to the inner wall of the hollow ring (67). Multiple through holes are provided on the inner wall of the hollow ring (67), and multiple branch pipes (68) are fixedly connected to the wall of the through holes. The air outlet of the branch pipe (68) is fixedly connected to the inner wall of the feed hopper (11). A fixing frame (69) is fixedly connected to the outer wall of the hollow ring (67). A temperature sensor (610) is fixedly connected to the outer wall of the fixing frame (69) by a nut. An insertion hole is provided on the outer wall of the hollow ring (67) that cooperates with the detection end of the temperature sensor (610). The detection end of the temperature sensor (610) is located inside the annular cavity of the hollow ring (67). A sealing ring (611) that cooperates with the inner wall of the insertion hole is fixedly sleeved on the rod wall of the temperature sensor (610). The hot air reuse mechanism (7) includes a rubber strip (71) and a hollow buffer block (72) fixedly connected to the inner wall of the feed pipe (2). The outer walls of the rubber strip (71) and the hollow buffer block (72) are fixedly connected to an arc-shaped fine mesh filter plate (73). Rubber sheets (74) are fixedly connected to both sides of the arc-shaped fine mesh filter plate (73). The two ends of the rubber strip (71) and the hollow buffer block (72) are fixedly connected to the surfaces of the two rubber sheets (74) respectively. The bottom end of the rubber sheet (74) is fixedly connected to the inner wall of the feed pipe (2). The outer wall of the feed pipe (2) located inside the arc-shaped fine mesh filter plate (73) is fixedly connected to an arc-shaped pipe (75). The top end of the arc-shaped pipe (75) is fixedly connected to the bottom cavity of the processing box (3). The raw material humidity measuring mechanism (8) includes an L-shaped baffle plate (81) fixedly connected to the inner wall of the feed hopper (11). The upper surface of the horizontal part of the L-shaped baffle plate (81) is provided with a fixed through hole, and a laser humidity sensor (82) is fixedly connected to the wall of the fixed through hole. A hollow metal block (83) is fixedly connected to the lower surface of the horizontal part of the L-shaped baffle plate (81). An air outlet (84) is provided on the outer wall of the hollow metal block (83) near the laser humidity sensor (82). A metal tube (85) is fixedly connected to the tube wall of the hollow metal block (83). The bottom end of the metal tube (85) is fixedly connected to the inner wall of the hollow ring (67).

2. The vertical mill equipment for high-carbon ferrochrome smelting raw materials according to claim 1, characterized in that, The transmission mechanism (5) includes a U-shaped frame (51) and a PLC controller (52) fixedly connected to the outer wall of the processing box (3). A geared motor (53) is fixedly connected to the outer wall of the U-shaped frame (51). The output end of the geared motor (53) is fixedly connected to the side end of one of the pressure rollers (41) through a safety coupling. Both pressure rollers (41) are fixedly fitted with transmission gears (54) near the side ends of the U-shaped frame (51). The two transmission gears (54) mesh with each other.

3. The vertical mill equipment for high-carbon ferrochrome smelting raw materials according to claim 1, characterized in that, The material guiding mechanism (9) includes two inclined plates (91) that are fixedly and obliquely connected to the inner wall of the bottom end of the processing box (3). A scraper (92) is fixedly and obliquely connected to one side of each of the two inclined plates (91). The tops of the scraper (92) and the inclined plates (91) are in contact with the outer wall of the arc-shaped wear-resistant inner lining plate (43). A partition plate (93) is fixedly connected to one side of each of the two inclined plates (91) that is opposite to each other. The side wall of the partition plate (93) is fixedly connected to the inner wall of the processing box (3). The upper surface of one of the partition plates (93) is provided with a partition plate. The heat cylinder (61) has a through hole that matches the outer wall. The air pump (62) is located below the partition (93). The two partitions (93) divide the internal cavity of the processing box (3) into an open area (94) and a sealed area (95). The lower surface of the box cover (10) is fixedly connected to two inclined guide strips (96). The bottom end of the guide strips (96) contacts the outer wall of the arc-shaped wear-resistant inner liner (43). The two inclined plates (91) are fixedly connected to two inclined and symmetrically arranged arc-shaped guide plates (97) on opposite sides.

4. The vertical mill equipment for high-carbon ferrochrome smelting raw materials according to claim 1, characterized in that, The lower surface of the processing box (3) is fixedly connected to two symmetrically distributed support columns (12), and the bottom end of the support column (12) is fixedly connected to a fixed square plate (13).

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