Machine for grinding pulverized coal for power plant

Abstract

The invention discloses a coal mill for milling pulverized coal in a power plant, and belongs to the technical field of pulverized coal milling equipment. The coal mill comprises a machine base, a speed reducer, a millstone, a nozzle ring, a grinding roller device, a pressing frame, a hinged shaft device, a loading oil cylinder, a high-pressure oil station, a separator, a permanent magnet motor, a slag discharging box, a sealing pipeline system and the like. A speed reducer on a machine base is connected with a permanent magnet motor through a coupler to drive a grinding disc to rotate, a grinding roller device is connected with a loading oil cylinder through a pull rod loading device, and the loading oil cylinder is communicated with a high-pressure oil station through a high-pressure oil pipeline to achieve pressure adjustment. The separator on the upper portion of the machine shell is of a cylindrical rotor dynamic separation structure, and the slag discharging box below the machine base is of a sealed structure. By optimizing the milling structure and adopting the permanent magnet motor, high-pressure oil station loading adjustment and efficient separation technology, the problems that an existing coal mill is insufficient in output, high in energy consumption, large in vibration and substandard in environmental protection are solved, the coal milling output reaches 42 t / h or above, the coal powder fineness R90 is smaller than 10%, the powder milling power consumption is reduced by 10%-15%, operation is stable, and the deep peak regulation requirement of a unit is met.

Description

Technical Field

[0001] This invention relates to the field of coal pulverizing equipment technology for power plants, specifically to a coal mill with optimized structure, high efficiency and energy saving, and stable operation, suitable for the deep peak shaving needs of units under coal quality fluctuation scenarios. Background Technology

[0002] In the pulverized coal preparation system of a thermal power plant, the coal mill is the core equipment, and its operating performance directly affects the boiler combustion efficiency, unit energy consumption, and environmental protection indicators. The No. 2 boiler of Datang Qingyuan Thermal Power Co., Ltd. currently has ZGM95N-I and ZGM95G-I type coal mills. After commissioning, due to changes in the coal market, the actual quality of the purchased coal deviated significantly from the design value. Specifically, the calorific value of the coal decreased, the volatile matter decreased, and the Hardgrove Grindability Index (HGI) dropped to 45-61, far below the design requirement of 63-83.

[0003] The aforementioned changes in coal quality have led to numerous problems with existing coal mills: While ensuring a pulverized coal fineness of R90=10%, the actual output of a single coal mill is only about 35t / h. At full load, five coal mills need to be operational simultaneously with no backup units, resulting in boiler operating efficiency remaining at a low level of 87%-89% for an extended period. Fly ash has a carbon content exceeding 6%, leading to significant fuel waste. Pulverizing power consumption has increased significantly, raising operating costs. Furthermore, the coal mills vibrate violently under low-output conditions, and the emission of coke and gravel poses a pollution problem, failing to meet the unit's deep peak-shaving requirements and environmental policy standards.

[0004] The core reasons for the aforementioned problems are the structural defects of existing coal mills: First, the grinding contact area between the grinding rollers and the grinding disc is insufficient, the grinding profile design is unreasonable, and the adaptability to low-quality coal is poor; second, the reducer speed is too low and the gear material has insufficient wear resistance, limiting transmission efficiency; third, the loading system cannot achieve online pressure adjustment, and the coal grinding rate adjustment range is narrow; fourth, the separator adopts a traditional separation structure, resulting in low separation efficiency and a high number of coarse coal powder circulations, further increasing energy consumption; fifth, the drive motor has high energy consumption, and the slag discharge system has poor sealing performance, posing an environmental pollution risk. Therefore, it is urgent to comprehensively improve the structure and auxiliary systems of existing coal mills to solve the series of operational problems caused by coal quality fluctuations. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing coal mills in scenarios where the coal quality deviates from the design value, such as insufficient output, high energy consumption, large vibration, narrow adjustment range, and failure to meet environmental protection standards. The invention provides a coal mill with a coal milling output of more than 42t / h, coal powder fineness R90 < 10%, low operating vibration, wide adjustment range of coal milling volume, low power consumption, and excellent environmental performance.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: The coal mill of the present invention includes a general assembly structure and core functional components. The general assembly structure consists of a permanent magnet motor, a coupling and protective cover, a reducer, a base, a slag discharge box, a transmission disc and scraper device, a grinding disc and nozzle ring, a grinding roller device, a pressure frame and hinge shaft device, a housing, a tie rod loading device, a loading cylinder, a separator, a high-pressure oil pipeline, a high-pressure oil station and a sealing pipeline system, and also includes auxiliary components such as a thin oil station, a lubricating oil pipeline, an explosion-proof steam pipeline and a grinding roller sealing air duct.

[0007] The base serves as the overall support foundation, on which a reducer is fixedly installed. The reducer is connected to the permanent magnet motor via a coupling and a protective cover. The output end of the reducer is fixedly connected to the transmission disc and scraper device. The transmission disc and scraper device are coaxially fixedly assembled with the grinding disc and nozzle ring above them, realizing the stable transmission of power from the motor to the grinding disc.

[0008] Three grinding roller devices are installed above the grinding disc and nozzle ring. The grinding roller devices are rotatably connected to the pressure frame and the pressure frame and the pressure frame and the pressure frame and the pressure frame and the pressure frame and the pressure frame and the pressure frame are fixedly connected to the tie rod loading device. The tie rod loading device is connected to the loading cylinder through a transmission. The loading cylinder is connected to the high-pressure oil station through a high-pressure oil pipeline. The high-pressure oil station is equipped with a control circuit, which constitutes an online adjustable loading system.

[0009] The casing is located outside the grinding disc and nozzle ring and is fixedly connected to the base. The separator is fixedly installed on the upper part of the casing. The separator is a cylindrical rotor dynamic separation structure with a reducer gear transmission mechanism inside to achieve efficient and precise separation of coal powder.

[0010] The output end of the sealed piping system is connected to the sealed interface of the grinding roller device. A slag discharge box is fixedly installed under the machine base. The slag discharge box is a sealed collection structure to avoid pollution from the discharge of stones and coal. The thin oil station is fixedly installed on one side of the machine base and provides lubrication to the reducer through the lubrication oil pipeline. One end of the grinding roller sealing air duct is fixedly connected to the sealed piping system, and the other end is connected to the sealing cavity of the grinding roller device. The explosion-proof steam pipeline is fixedly installed on the outside of the machine casing to meet the explosion-proof protection requirements.

[0011] The grinding profile of the grinding roller device is designed as a deep tile shape, and the working diameter of the grinding disc is matched with the grinding diameter of the grinding roller to increase the grinding contact area; the reducer uses carburized and quenched steel gears to increase the speed and optimize the grinding efficiency; the grinding roller device is equipped with metal composite roller sleeves, and metal composite liners are correspondingly set on the grinding disc and nozzle ring to extend the service life of wear-resistant parts.

[0012] The high-pressure oil station includes a motor junction box, an oil filter outlet and an oil pump suction port, an oil cylinder drain port, a loading port, an overflow valve return port, a vibration damping port, a heater, a vibration damping accumulator outlet, instrument components, a cooling water outlet, a cooling water inlet, an oil filter inlet, and below the return oil filter. The loading port and the oil cylinder drain port are connected to the high-pressure oil pipeline. The overflow valve return port, the vibration damping port, and the vibration damping accumulator outlet are built-in interfaces of the high-pressure oil station. The heater and instrument components are fixedly installed inside the high-pressure oil station's enclosure.

[0013] The high-pressure oil pipeline consists of seamless steel pipes, crimped rubber hoses, welded straight pipe fittings, tee fittings, elbows, and matching seals. The seamless steel pipes and pipe fittings are fixedly connected by argon arc welding, while the crimped rubber hoses and pipe fittings are detachably connected. One end of the high-pressure oil pipeline is fixedly connected to the loading oil port and the oil drain port of the oil cylinder, and the other end is fixedly connected to the inlet and outlet ports of the loading oil cylinder. The pipeline layout follows the principles of shortest path, no interference, and easy disassembly.

[0014] The separator includes a lower separator section, a stationary section, a separator gate, a rotating section, an upper separator section, a drive section, a motor dust cover, sealant, ceramic fiber twisted rope, and a ceramic fiber twisted rope. The lower separator section is fixedly connected to the upper separator section. The stationary section is fixedly assembled on the inner side of the upper and lower separator sections. The rotating section is rotatably connected to the stationary section via bearings. The drive section is fixedly installed on the outer side of the upper separator section, and its output end is connected to the rotating section for transmission. The drive section is fixedly connected to a dedicated drive motor. The joint surfaces of the separator are sealed together by ceramic fiber twisted rope, sealant, and MoS2. The motor dust cover is detachably assembled on the outer side of the dedicated drive motor.

[0015] The slag discharge box includes a control cabinet, a stone and coal transfer box, a sealing and pressing device, a slag discharge valve, a feed pipe, a level gauge, and expansion bolts. The stone and coal transfer box is fixedly connected to the lower part of the machine base by expansion bolts. The sealing and pressing device is fixedly assembled on the upper part of the stone and coal transfer box. The feed pipe is fixedly connected to the sealing and pressing device and welded to the flange and sealing mechanism bracket. The slag discharge valve is fixedly assembled at the lower discharge port of the stone and coal transfer box. The flange faces of the slag discharge valve are sealed together by a metal spiral wound gasket. The level gauge is fixedly installed on the side wall of the stone and coal transfer box. The control cabinet is electrically connected to the slag discharge valve and the level gauge.

[0016] Power transmission and grinding process: After the permanent magnet motor starts, it transmits power to the reducer through a coupling and protective cover. The reducer is optimized (carburized and quenched steel gears + 31.8 r / min speed) to achieve power amplification and stable output, driving the transmission disc and scraper device to rotate, which in turn drives the grinding disc and nozzle ring to rotate synchronously. Raw coal falls into the center of the grinding disc through the feed inlet and moves towards the edge of the grinding disc under the action of centrifugal force, forming a squeezing and grinding action with the three grinding rollers above the grinding disc. The deep tile-shaped grinding profile of the grinding rollers and the matching working diameter of the grinding disc increase the grinding contact area. The metal composite roller sleeve and liner improve wear resistance, ensuring efficient grinding of low-quality coal.

[0017] Loading pressure regulation process: The high-pressure oil station, as the core of the reaction force loading control, adjusts the output pressure in real time through the control circuit. High-pressure oil is delivered to the loading cylinder through the high-pressure oil pipeline. The loading cylinder applies pressure to the pressure frame and hinge shaft device through the pull rod loading device, thereby adjusting the grinding pressure of the grinding roller on the raw coal. According to the unit load requirements and coal quality, the loading pressure can be continuously adjusted online, so that the coal grinding volume adjustment range covers 20%-100%, adapting to the output requirements under different working conditions. The special arrangement of the high-pressure oil pipeline (no twisting, with stabilizing springs at vertical bends) and the welding process (argon arc welding + Class II weld standard) ensure stable pressure transmission and avoid leakage.

[0018] Coal powder separation process: After grinding, the coal powder enters the separator at the top of the casing under the carry of primary air. The separator adopts a cylindrical rotor dynamic separation structure. A dedicated drive motor drives the gear transmission mechanism of the drive unit to rotate, thereby driving the rotating part to rotate. Under the action of centrifugal force and airflow, the coarse coal powder is separated and falls back to the grinding disc for re-grinding, while the fine coal powder (R90 < 10%) enters the boiler for combustion through the separator's outlet. The multi-layer sealing structure (ceramic fiber twisted rope + sealant + MoS2) at the separator's joint surface ensures sealing performance and prevents fine coal powder leakage. At the same time, the optimized flow field design reduces the number of coarse coal powder circulations and improves separation efficiency.

[0019] Slag discharge and sealing lubrication process: During the grinding process, the coke and stones (non-grindable impurities) produced fall into the slag discharge box below the machine base through the nozzle ring on the edge of the grinding disc. The feed pipe guides the coke and stones to the coke and stones transfer box. The level gauge monitors the material level in the box in real time. After reaching the set value, the control cabinet controls the slag discharge valve to open and discharge slag. The metal spiral wound gasket sealing structure of the slag discharge valve prevents dust leakage. The sealing pipeline system introduces sealing air into the sealing cavity of the grinding roller device through the grinding roller sealing air duct, forming a pressure difference (ΔP>2kPa) with the primary air to prevent coal dust from entering the grinding roller bearing. The thin oil station delivers lubricating oil to the reducer through the lubricating oil pipeline to ensure the lubrication and cooling of the transmission components and extend their service life.

[0020] Safety protection process: The explosion-proof steam pipeline on the outside of the casing is connected to explosion-proof saturated steam of 0.4-0.6MPa. When an abnormality occurs inside the coal mill, the steam is quickly injected to cool down and reduce pressure, meeting the explosion-proof standard of 0.15MPa. The dustproof sleeve of the separator's motor, the dustproof and rainproof measures of the exposed outlet, and the sealing design of the slag discharge box ensure the stable operation of the equipment in different environments and reduce the risk of environmental pollution. Beneficial effects

[0021] By optimizing the grinding structure of the grinding rollers and grinding discs, increasing the speed of the reducer, and adopting efficient separation technology, the output of a single coal mill can be increased to more than 42t / h while ensuring that the fineness of coal powder R90 < 10%. This allows four coal mills to achieve stable coal powder supply when the unit is running at full load, with one standby unit reserved to improve system reliability.

[0022] The application of permanent magnet motors reduces pulverizing power consumption by 10%-15%, with a reduction of 0.82 kWh / t per unit, resulting in annual electricity savings of approximately 316,000 yuan; the replacement of the original five coal mills with four mills lowers boiler flue gas temperature by about 1°C, further reducing coal consumption; the efficient separation of the separator reduces the number of times coarse coal powder is circulated and ground, thus reducing energy consumption.

[0023] The fineness of pulverized coal is precisely controlled at R90 < 10%, ensuring that the pulverized coal is fully combusted in the boiler, significantly reducing the carbon content of fly ash, increasing boiler efficiency to near the design value, and reducing fuel waste.

[0024] The loading adjustment function of the reaction force high-pressure oil station reduces equipment vibration under low output conditions; the service life of the metal composite wear-resistant parts of the grinding roller and grinding disc is no less than 8000 hours; the reducer adopts carburized and quenched steel gears, which have high transmission efficiency and low failure rate; the optimized design of the sealing and lubrication system further reduces the frequency of equipment failure and extends the maintenance cycle.

[0025] The coal milling rate adjustment range covers 20%-100%, which can adapt to the load change requirements of deep peak shaving of the unit and solve the problem of narrow adjustment range of traditional coal mills.

[0026] The sealed design of the slag discharge box and the orderly discharge of stones and coal avoid dust pollution; the improved overall sealing performance of the equipment reduces coal powder leakage and meets environmental protection policy requirements. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall assembly structure of the present invention; Figure 2 This is a front view schematic diagram of the permanent magnet motor structure of the present invention; Figure 3 This is a schematic diagram of the left-side structure of the permanent magnet motor of the present invention; Figure 4 This is a rear view schematic diagram of the high-pressure oil station of the present invention; Figure 5 This is a right-side schematic diagram of the high-pressure oil station of the present invention; Figure 6 This is a front view structural schematic diagram of the high-pressure oil station of the present invention; Figure 7 This is a schematic diagram of the left-side structure of the high-pressure oil station of the present invention; Figure 8 This is a top view of the high-pressure oil station structure of the present invention; Figure 9 This is a schematic diagram of the high-pressure oil pipeline structure of the present invention; Figure 10 This is a schematic diagram of the high-pressure oil pipeline structure of the present invention; Figure 11 This is a schematic diagram of the three-structure high-pressure oil pipeline of the present invention; Figure 12 This is a schematic diagram of the separator structure of the present invention; Figure 13 This is a schematic diagram of the slag discharge box control cabinet structure of the present invention; Figure 14 This is a schematic diagram of the left-side structure of the slag discharge box of the present invention; Figure 15 This is a front view structural diagram of the slag discharge box of the present invention; In the picture: 1. Permanent magnet motor; 2. Coupling and protective cover; 3. Reducer; 4. Machine base; 5. Slag discharge box; 7. Transmission disc and scraper device; 8. Grinding disc and nozzle ring; 9. Grinding roller device; 10. Pressure frame and hinge shaft device; 11. Machine housing; 12. Tie rod loading device; 13. Loading cylinder; 14. Separator; 16. Sealed piping system; 17. Explosion-proof steam piping; 18. High-pressure oil piping; 19. High-pressure oil station; 20. Lubricating oil piping; 21. Thin oil station; 22. Grinding roller sealing duct; 23. Nameplate; 51. Control... 52. Stone and Coal Transfer Box; 53. Sealing and Pressing Device; 54. Slag Discharge Valve; 55. Feed Pipe; 56. Level Gauge; 57. Expansion Bolt; 141. Lower Separator Section; 142. Static Section; 143. Separator Gate; 144. Rotating Section; 145. Upper Separator Section; 146. Drive Unit; 147. Motor Dustproof Shell; 148. Sealant; 149. Ceramic Fiber Twisted Rope ∅6; 1410. Ceramic Fiber Twisted Rope 15X15; 191. Motor Junction Box; 192. Oil Filter. At the outlet and oil pump suction port, 193 is the oil drain port of the oil cylinder, 194 is the loading port, 195 is the overflow valve return port, 196 is the vibration damping port, 197 is the heater, 198 is the outlet of the vibration damping accumulator, 199 is the instrument assembly, 1910 is the cooling water outlet, 1911 is the cooling water inlet, 1912 is the inlet of the oil filter and below the return oil filter, 181 is the seamless steel pipe DN20Sch40S, 182 is the seamless steel pipe DN10Sch40S, 1811 is the seamless steel pipe DN 40Sch80s, 1815 crimped hose 22III-1500, 1810 crimped hose 16III-1500, 189 crimped hose 45III-1000, 1829 welded straight pipe fitting 28, 1828 welded straight pipe fitting 18, 1819 tee fitting 28, 1812 tee fitting 18, 1824 45° elbow DN40I series, 1823 90° elbow DN40I series. Detailed Implementation

[0028] 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.

[0029] like Figure 1-15 As shown; A machine used in power plants for grinding pulverized coal.

[0030] This implementation plan addresses the technical problems existing in the prior art, such as those disclosed in the background section above, where "the structural defects of existing coal mills are the core cause of the aforementioned problems: firstly, the grinding contact area between the grinding rollers and the grinding disc is insufficient, the grinding profile design is unreasonable, and the adaptability to low-quality coal is poor; secondly, the speed of the reducer is too low and the wear resistance of the gear material is insufficient, limiting the transmission efficiency; thirdly, the loading system cannot achieve online pressure adjustment, and the coal grinding volume adjustment range is narrow; fourthly, the separator adopts a traditional separation structure, resulting in low separation efficiency, numerous coarse coal powder circulations, and further increasing energy consumption; fifthly, the drive motor has high energy consumption, and the slag discharge system has poor sealing performance, posing an environmental pollution risk." Considering practical use, this problem is clearly a real and difficult-to-solve issue. Therefore, to solve this technical problem, a machine for grinding coal powder used in power plants is provided.

[0031] Example 1

[0032] like Figure 1-15 As shown; This embodiment provides a coal mill for grinding coal powder in a power plant, the specific structure of which is as follows: Overall assembly structure The coal mill assembly is supported by a base 4, which is welded from 16Mn steel plate to ensure overall rigidity. A reducer 3 is bolted onto the base 4. The reducer 3 is matched to the coal mill's output requirements, and its internal gears are made of carburized and quenched steel, achieving a hardness of HRC60-62 after heat treatment. Its speed is set at 31.8 r / min, which improves grinding efficiency by 7.4% compared to the traditional reducer's 29.6 r / min. The input end of the reducer 3 is connected to a permanent magnet motor 1 via a coupling and protective cover 2. The permanent magnet motor 1 is a YK0500-6 model with a rated power of 475 kW, a rated voltage of 6 kV, and a speed of 1000 r / min. It rotates counter-clockwise when viewed from the drive end, with a static load of 23.1 kN on each side and a rated electromagnetic pull of 4.3 kN. Compared to traditional asynchronous motors, energy consumption is reduced by 10%-15%.

[0033] The output end of the reducer 3 is fixedly connected to the transmission disc and scraper device 7 by a flat key. The transmission disc and scraper device 7 are coaxially welded and fixed to the grinding disc and nozzle ring 8. The working diameter of the grinding disc in the grinding disc and nozzle ring 8 is adapted to the grinding diameter of the grinding roller device 9 to ensure the maximum grinding contact area. The liner plate on the grinding disc and nozzle ring 8 is made of metal composite material with a thickness of 50mm and excellent wear resistance.

[0034] Three grinding roller devices 9 are evenly arranged above the grinding disc and nozzle ring 8. The grinding profile of the grinding roller device 9 is a deep tile shape. The roller body is fitted with a metal composite roller sleeve with a thickness of 60mm, which is fixed to the roller body by a heat fitting process. The grinding roller device 9 is rotatably connected to the pressure frame and hinge shaft device 10 through a hinge shaft. The hinge shaft is made of 40Cr material and has been heat treated to ensure rotational flexibility. The top of the pressure frame and hinge shaft device 10 is fixedly connected to the tie rod loading device 12 by bolts. The lower end of the tie rod loading device 12 is hinged to the piston rod of the loading cylinder 13. The loading cylinder 13 is fixedly installed on the top bracket of the housing 11 through a flange. The oil inlet and outlet of the loading cylinder 13 are connected to the high-pressure oil station 19 through the high-pressure oil pipeline 18.

[0035] The housing 11 adopts a segmented welded structure, made of Q235B steel, and covers the outside of the grinding disc and nozzle ring 8. The lower part of the housing 11 is fixedly connected to the base 4 with bolts, and a sealing gasket is installed on the mating surface. The separator 14 is fixedly installed on the upper part of the housing 11 via a flange. The outer shell of the separator 14 is made of 16Mn steel, with an overall height of 1800mm. The internal space is optimized to improve separation efficiency. The slag discharge box 5 is fixedly mounted on the lower part of the base 4 with expansion bolts 57. The slag discharge box 5 is model ODRG-MY, with a volume of approximately 0.7m³, an operating pressure of 20kPa, and an operating temperature of 300℃, suitable for the slag discharge requirements of the coal mill.

[0036] The sealed pipeline system 16 is fixed to the outside of the housing 11 by a bracket, and its output end is connected to the sealing interface of the grinding roller device 9 through a hose; a thin oil station 21 is fixedly installed on the ground on one side of the base 4, and the oil outlet of the thin oil station 21 is connected to the oil inlet of the reducer 3 through the lubricating oil pipeline 20, and the return oil outlet recovers the lubricating oil through the pipeline to form a circulating lubrication; one end of the grinding roller sealing air duct 22 is welded to the sealed pipeline system 16, and the other end is threaded to the sealing cavity of the grinding roller device 9; the explosion-proof steam pipeline 17 is fixedly assembled to the outside of the housing 11 by a pipe clamp and connected to the saturated steam system of the power plant, and the steam pressure is controlled at 0.4-0.6MPa.

[0037] High-pressure oil station structure like Figure 4-8As shown, the high-pressure oil station 19 is constructed from Q235B steel plate and has external dimensions of 1745mm×1405mm×1250mm. The heater 197, instrument assembly 199, and hydraulic pump set are fixedly installed inside the housing. The motor junction box 191 is fixed to the side of the housing and is electrically connected to the motor of the hydraulic pump unit; the oil filter outlet and oil pump suction port 192 are located at the bottom of the housing and are connected to the outlet pipe of the oil filter; the oil drain port 193 and the loading port 194 of the oil cylinder are both φ18X2.0 and are connected to the high-pressure oil pipeline 18 through flanges; the overflow valve return port 195 and the vibration damping port 196 are both φ28X3.0 and are internal interfaces of the housing, respectively connected to the overflow valve and the vibration damping device; the vibration damping accumulator outlet 198 is φ42X3.0 and is connected to the output end of the accumulator; the cooling water outlet 1910 and the cooling water inlet 1911 are located on the side of the housing and are connected to the cooling water system for cooling the hydraulic oil; the oil filter inlet and the return oil filter below 1912 are located at the bottom of the housing and are connected to the inlet of the return oil filter.

[0038] High-pressure oil pipeline structure like Figure 9-11 As shown, the high-pressure oil pipeline 18 includes seamless steel pipes DN20Sch40S, DN10Sch40S, DN40Sch80S, crimped hoses 22III-1500, 16III-1500, 45III-1000, welded straight pipe fittings 28, tee fittings 28, 45° elbows DN40I series, 90° elbows DN40I series, and matching sealing components such as combination sealing gaskets and O-rings.

[0039] Seamless steel pipes and pipe fittings are fixedly connected by argon arc welding. Before welding, the steel pipes and pipe fittings are pickled and passivated. After welding, they are cleaned and dried. The weld quality is not lower than the Class II welding standard. The weld size is 3mm unless otherwise specified. The crimped hoses and pipe fittings are detachably connected by crimping process. During installation, ensure that there is no twisting. A bending stabilizing spring is installed at the connection of vertical bends to prevent the hose from detaching. The high-pressure oil pipeline 18 is arranged after the installation of other grinding body components and high-pressure oil station 19. The pipeline route follows the principle of shortest path, no interference with other components, and easy disassembly. During on-site installation, the pipe fittings and gaskets are cut and welded according to the actual situation. Before final assembly, the two ends are wrapped and sealed.

[0040] Separator Structure like Figure 12As shown, the lower separator 141 and upper separator 145 of separator 14 are fixedly connected by bolts, and a sealing structure is provided at the joint surface; the stationary part 142 is welded and fixed to the inner side of the upper separator 145 and the lower separator 141 to form a fixed flow channel; the rotating part 144 is a cylindrical rotor, which is rotatably connected to the stationary part 142 through bearings. The rotor is made of 16Mn and its surface is treated with wear resistance; the separator door 143 is installed on the side of the upper separator 145 by hinges for easy maintenance; the drive unit 146 is fixedly installed on the outside of the upper separator 145. On the side, an internal gear transmission mechanism is provided. The output end of the drive unit 146 is connected to the input end of the rotating part 144 through a coupling. The drive unit 146 is bolted to the dedicated drive motor. The dedicated drive motor rotates clockwise (viewed from the top of the motor towards the output shaft) and has a speed of 73~730 r / min. The mating surface of the separator 14 is sealed with multiple layers of ceramic fiber twisted rope ∅6, ​​ceramic fiber twisted rope 15X15, sealant 148 and MoS2. The motor dust cover 147 is detachably mounted on the outside of the dedicated drive motor by bolts, which serves as a dust protection function.

[0041] The rotor and hollow shaft of separator 14 are welded and fixed to the rotating part 144. Before leaving the factory, a dynamic balance test is carried out according to the drawing requirements to ensure smooth operation. When leaving the factory, the special drive motor and the upper coupling are removed, the large tooth surface of the turntable bearing and the small gear of the bearing are coated with vapor phase rust inhibitor, and the housing is treated with dustproof and rainproof measures. During on-site installation, the bolts of the motor base are wrapped with Teflon tape, and the lower end face of the motor base is coated with sealant.

[0042] Slag Discharge Box Structure like Figure 13-15 As shown, the stone and coal transfer box 52 of the slag discharge box 5 is fixedly connected to the lower part of the machine base 4 by expansion bolts 57. The stone and coal transfer box 52 is made of 16Mn and weighs 150KG. The sealing and pressing device 53 is fixedly assembled on the upper part of the stone and coal transfer box 52 by bolts. It is made of 16Mn and weighs 70KG. The guide pipe 55 is made of 16Mn and weighs 80KG. It is welded and fixed to the sealing and pressing device 53. The guide pipe 55 is also welded and fixed to the flange and sealing mechanism support on site. There are two slag discharge valves 54. Each of the following components weighs 65KG and is fixedly installed at the lower discharge port of the stone and coal transfer box 52. The flange faces of the slag discharge valve 54 are sealed together by a metal spiral wound gasket. The level gauge 56 is fixedly installed on the side wall of the stone and coal transfer box 52, weighing 10KG, and is used to monitor the level of stone and coal in the box. The control cabinet 51 weighs 80KG and its installation position is determined according to the actual site conditions. It is electrically connected to the slag discharge valve 54 and the level gauge 56 to realize automatic control of slag discharge. The air inlet pipe is made of φ14×1 stainless steel pipe and is connected to the sealing and pressing device 53.

[0043] Installation and Operation Procedures Basic installation: Fix the base 4 on the preset foundation, level and align it, and then tighten the anchor bolts; install the reducer 3, adjust the level, and ensure that the coaxiality error between the input end and the output end of the permanent magnet motor 1 is ≤0.05mm; install the coupling and protective cover 2, and tighten the connecting bolts.

[0044] Grinding component installation: Fix the transmission disc and scraper device 7 to the output end of the reducer 3, install the grinding disc and nozzle ring 8 and tighten them; install the grinding roller device 9 on the pressure frame and hinge device 10 through the hinge shaft, adjust the gap between the grinding roller and the grinding disc to ensure uniform grinding contact; install the tie rod loading device 12 and loading cylinder 13, and tighten the connecting bolts.

[0045] Housing and separator installation: The housing 11 is hoisted and welded into shape in sections, and fixedly connected to the base 4; the lower separator 141 of the separator 14 is fixed to the upper flange of the housing 11, and the stationary section 142, the rotating section 144, the upper separator 145 and the drive section 146 are installed in sequence. A special drive motor is installed and connected to the coupling, and the motor dust cover 147 is assembled; ceramic fiber twisted rope ∅6, ​​ceramic fiber twisted rope 15X15, sealant 148 and MoS2 are installed on the mating surface of the separator 14 to ensure reliable sealing.

[0046] Auxiliary system installation: Install the high-pressure oil station 19 and fix it on the preset foundation; arrange the high-pressure oil pipeline 18, connecting the loading cylinder 13 to the oil drain port 193 and loading port 194 of the high-pressure oil station 19, treat the welded joints according to the standard, install the seals and conduct a pressure test to ensure no leakage; install the thin oil station 21 and the lubricating oil pipeline 20, connecting the lubricating oil pipeline 20 to the inlet and outlet oil ports of the reducer 3; install the sealing pipeline system 16, the grinding roller sealing air duct 22 and the explosion-proof steam pipeline 17, and connect the corresponding interfaces.

[0047] Slag discharge system installation: Fix the stone and coal transfer box 52 to the bottom of the machine base 4 with expansion bolts 57, install the sealing and clamping device 53, the guide pipe 55, the slag discharge valve 54 and the level gauge 56, and connect the air inlet pipe; install the control cabinet 51 according to the site conditions, wire the wires and debug the control program.

[0048] Commissioning and Operation: Check the tightness of all component connections; inject medium-load industrial gear oil N320 (GB5903-86) into reducer 3, with an oil volume of approximately 300 liters and an oil filtration accuracy of 25μm; inject hydraulic oil into high-pressure oil station 19; start thin oil station 21 and high-pressure oil station 19; and debug the loading pressure regulation function; start permanent magnet motor 1; run it under no-load to check the rotation of the grinding disc and grinding rollers to ensure there is no jamming or vibration; start the dedicated drive motor of separator 14; debug the sealing air system to ensure that the pressure difference ΔP between sealing air and primary air is >2kPa; initially, set the opening of the separator sealing air butterfly valve to >45°; conduct a load test run, adjust the loading pressure and separator speed to ensure that the coal mill output reaches more than 42t / h and the coal powder fineness R90 <10%; and put it into normal use after stable operation.

[0049] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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 coal pulverizing mill for a power plant, characterized by, It includes permanent magnet motor (1), coupling and protective cover (2), speed reducer (3), base (4), slag discharge box (5), transmission disc and scraper device (7), grinding disc and nozzle ring (8), grinding roller device (9), press frame and hinge shaft device (10), machine shell (11), pull rod loading device (12), loading oil cylinder (13), separator (14), high pressure oil pipeline (18), high pressure oil station (19) and sealing pipeline system (16), it also includes thin oil station (21), lubricating oil pipeline (20), explosion-proof steam pipeline (17) and grinding roller sealing air pipe (22), the base (4) is the whole support foundation, the speed reducer (3) is fixedly installed on it, the speed reducer (3) is driven by the transmission disc and scraper device (7) in turn and drives the grinding disc and nozzle ring (8) to rotate coaxially through the coupling and protective cover (2) and the permanent magnet motor (1), the grinding disc and nozzle ring (8) are correspondingly provided with the grinding roller device (9) above, the grinding roller device (9) is rotatably connected with the press frame and hinge shaft device (10) through the hinge shaft, the press frame and hinge shaft device (10) are drivingly connected with the loading oil cylinder (13) through the pull rod loading device (12), the loading oil cylinder (13) is communicated with the high pressure oil station (19) configured with control circuit through the high pressure oil pipeline (18), the machine shell (11) is arranged outside the grinding disc and nozzle ring (8) and is fixedly connected with the base (4), the separator (14) of the cylindrical rotor dynamic separation structure is fixedly installed on the upper portion of the machine shell (11), the sealing pipeline system (16) is sealingly communicated with the grinding roller device (9), the base (4) is fixedly provided with the slag discharge box (5) below.

2. The coal mill of claim 1, wherein, The high pressure oil station (19) includes motor junction box (191), oil pump suction port and oil filter outlet (192), oil cylinder oil discharge port (193), loading oil port (194), overflow valve return oil port (195), damping oil port (196), heater (197), damping accumulator outlet (198), instrument assembly (199), cooling water outlet (1910), cooling water inlet (1911) and oil filter inlet and lower return filter (1912), the loading oil port (194) and the oil cylinder oil discharge port (193) are communicated with the high pressure oil pipeline (18), the overflow valve return oil port (195), the damping oil port (196) and the damping accumulator outlet (198) are all built-in interfaces of the high pressure oil station (19), the heater (197) and the instrument assembly (199) are fixedly assembled in the box body of the high pressure oil station (19).

3. The coal mill of claim 1, wherein, The high pressure oil pipeline (18) includes seamless steel pipe, buckling type rubber pipe, welded straight-through pipe joint, tee pipe joint, elbow and matching sealing element, the seamless steel pipe is fixedly connected with the pipe joint through argon arc welding, the buckling type rubber pipe is detachably connected with the pipe joint, one end of the high pressure oil pipeline (18) is fixedly communicated with the loading oil port (194) and the oil cylinder oil discharge port (193), the other end is fixedly communicated with the oil inlet and outlet of the loading oil cylinder (13).

4. The coal mill of claim 1, wherein, The separator (14) comprises a separator lower part (141), a static part (142), a separator gate (143), a rotating part (144), a separator upper part (145), a driving part (146), a motor dustproof cylinder (147), a sealant (148) and a ceramic fiber twisted rope; the separator lower part (141) is fixedly connected with the separator upper part (145), the static part (142) is fixedly assembled on the inner side of the separator upper part (145) and the separator lower part (141), the rotating part (144) is rotatably connected with the static part (142) through a bearing, the driving part (146) is fixedly installed on the outer side of the separator upper part (145), and the output end of the driving part (146) is in transmission connection with the rotating part (144), and the driving part (146) is fixedly connected with a special driving motor; the joint surface of the separator (14) is in sealing connection through the ceramic fiber twisted rope and the sealant (148), and the motor dustproof cylinder (147) is detachably assembled on the outer side of the special driving motor.

5. The coal mill of claim 1, wherein, The slag discharge box (5) comprises a control cabinet (51), a stone coal transfer box (52), a sealing and pressing device (53), a slag discharge valve (54), a material guide pipe (55), a material level meter (56) and expansion bolts (57); the stone coal transfer box (52) is fixedly connected with the lower part of the machine base (4) through the expansion bolts (57), the sealing and pressing device (53) is fixedly assembled on the upper part of the stone coal transfer box (52), the material guide pipe (55) is fixedly connected with the sealing and pressing device (53), and the material guide pipe (55) is fixedly connected with a flange and a sealing mechanism support through welding, the slag discharge valve (54) is fixedly assembled on the lower part of the stone coal transfer box (52), the flange surfaces of the slag discharge valve (54) are in sealing connection through metal winding pads, the material level meter (56) is fixedly installed on the side wall of the stone coal transfer box (52), and the control cabinet (51) is electrically connected with the slag discharge valve (54) and the material level meter (56).

6. The coal mill of claim 1, wherein, The thin oil station (21) is fixedly installed on one side of the machine base (4), one end of the lubricating oil pipeline (20) is fixedly communicated with the oil outlet of the thin oil station (21), the other end is fixedly communicated with the oil inlet of the speed reducer (3), one end of the mill roller sealing air pipe (22) is fixedly communicated with the sealing pipeline system (16), and the other end is fixedly communicated with the sealing cavity of the mill roller device (9), and the explosion-proof steam pipeline (17) is fixedly assembled on the outer side of the machine shell (11).

7. The coal mill of claim 4, wherein, The rotor and the hollow shaft of the separator (14) are fixedly connected with the rotating part (144), the inside of the driving part (146) is provided with a gear transmission mechanism, the gear transmission mechanism is fixedly connected with the input end of the rotating part (144), the large gear surface of the rotary disc bearing is in meshing connection with the output gear of the driving part (146), and the small gear of the rotary disc bearing is fixedly connected with the internal gear of the driving part (146).

8. The coal mill of claim 1, wherein, The output end of the permanent magnet motor (1) is fixedly connected with one end of a coupling and a protective cover (2), the other end of the coupling and the protective cover (2) is fixedly connected with the input end of a speed reducer (3), the mounting base of the permanent magnet motor (1) is fixedly connected with the ground, and the static load of each side of the permanent magnet motor (1) is 23.1kN, and the rated electromagnetic pull is 4.3kN.

9. The coal mill of claim 1, wherein, The number of the grinding roller devices (9) is three, the grinding profile line is set as a deep tile type, the working diameter of the grinding disc in the grinding disc and nozzle ring (8) is matched with the grinding diameter of the grinding roller device (9); the speed reducer (3) adopts a carburized quenched steel gear, the grinding roller device (9) is provided with a metal composite roller sleeve, and the metal composite lining plate is correspondingly arranged on the grinding disc and nozzle ring (8).

10. The coal mill of claim 1, wherein, The separator (14) is internally provided with a speed reducer gear transmission mechanism.

Images