Multi-stage air distribution four-channel pulverized coal combustion device

Abstract

The invention belongs to the field of pulverized coal combustors, particularly relates to a multi-stage air distribution four-channel pulverized coal combustion device, and provides the following scheme aiming at the problems that an existing pulverized coal combustor is uneven in mixing, non-adjustable in flame shape, difficult to move, large in primary air volume and rapid in refractory lining loss, and a spray head is leveled manually. The spray head is mounted on the rack in an angle-adjustable manner; the axial flow air channel pipe is fixedly connected to the spray head; the rotational flow air channel pipe is arranged in the axial flow air channel pipe; according to the pulverized coal burner, combustion is optimized through multi-stage air distribution, center air, rotational flow air, axial flow air and a pulverized coal channel are independently controlled, a flow field structure with the tight outer portion and the loose inner portion is formed, mixing of pulverized coal and air is enhanced, the burn-off rate is increased, oil and gas are mixed and atomized in a multi-stage mode, and the combustion efficiency is improved. Three-time mixing (primary mixing, secondary mixing and final mixing) of fuel oil is achieved through the hollow circular truncated cone block, the conical check block and the rotating blades, the atomization particle size is reduced, and combustion is sufficient.

Description

Technical Field

[0001] The present invention relates to the technical field of pulverized coal burners, and in particular to a four-channel pulverized coal combustion device with multi-stage air distribution. Background Art

[0002] Traditional pulverized coal burners are widely used in industrial kilns (such as cement rotary kilns and metallurgical heating furnaces), but they have the following technical defects: The single-channel or double-channel design results in a short mixing time of coal powder and air, local oxygen-deficient combustion produces CO and unburned carbon, and the burnout rate is low.

[0003] The fixed nozzle structure cannot adapt to kiln deformation or fluctuating coal quality, easily leading to flame offset and lining spalling. The heavy weight (over 5 tons) requires crane installation, making kiln switching time-consuming. Installation on inclined surfaces requires shims for adjustment, with an accuracy of ±5°, which cannot meet the requirements of high-precision combustion. A 15%-20% primary air flow is required to maintain flame stability, increasing exhaust heat loss. Large fluctuations in flame temperature lead to a high annual wear rate of the kiln lining and increased maintenance costs. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of uneven mixing of pulverized coal burners in the prior art: the single-channel or dual-channel design leads to a short mixing time of pulverized coal and air, local oxygen-deficient combustion produces CO and unburned carbon, and the burnout rate is low. The flame shape is not adjustable: the fixed nozzle structure cannot adapt to the deformation of the kiln body or the fluctuation of coal quality, which easily causes the problem of flame bias and kiln lining peeling. It is difficult to move: the overall weight is large (>5t), and it needs to rely on crane lifting, and it takes a long time to switch the kiln. The leveling of the nozzle depends on manual labor: when installing on an inclined ground, shims are required for adjustment, with an accuracy of ±5°, which cannot meet the requirements of high-precision combustion. The primary air volume is large: 15%-20% of the primary air is required to maintain flame stability, resulting in increased heat loss from smoke exhaust. The refractory lining wears out quickly: the flame temperature fluctuates greatly, the annual loss rate of the kiln lining is high, and the maintenance cost increases. A four-channel pulverized coal combustion device with multi-stage air distribution is proposed.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A four-channel pulverized coal combustion device with multi-stage air distribution includes a frame; The nozzle is installed on the frame with adjustable angle; Axial flow air channel tube, fixedly connected to the nozzle; The swirl air channel tube is arranged inside the axial air channel tube; The coal air channel pipe is arranged inside the swirl air channel pipe; The central air channel pipe is arranged inside the coal air channel pipe; The oil pipe conduit is arranged inside the central air channel pipe; Adjustment component, used to adjust the angle of the nozzle; Mixing assembly, used to mix fuel and air; Among them, the central air channel tube transports high-speed airflow to stabilize the flame root and cool the nozzle, the coal air channel tube transports coal powder, the swirl air channel tube generates swirl to promote the mixing of coal powder and air, and the axial air channel tube transports direct air to control the flame shape, forming a flow field structure that is tight outside and loose inside, thereby improving the burnout rate and reducing emissions.

[0006] In one possible design, the adjustment component includes: The sliding outer cylinder is slidably connected to the top of the supporting horizontal plate, and the supporting horizontal plate is fixedly installed on the top of the frame; A first operating hand wheel is rotatably connected to the top of the sliding outer cylinder; A second screw rod, threadedly passing through the first operating hand wheel and slidingly passing through the sliding outer cylinder; A lifting support plate is fixedly connected to the top of the second screw rod; A first screw rod is rotatably connected between the inner walls of both sides of the lifting support plate; A threaded slide is slidably connected to the top of the lifting support plate and is threadedly sleeved on the outer wall of the first screw rod; A second hand wheel is fixedly connected to one end of the first screw rod; The rotating seat is fixedly mounted on the top of the threaded slide; A fixed rectangular frame is rotatably connected to the top of the rotating base, and the inner walls on both sides of the fixed rectangular frame are rotatably connected to the second rotating shaft, and the nozzle is fixedly connected to the second rotating shaft; Among them, rotating the first operating hand wheel drives the second screw to move up and down to adjust the height of the nozzle, and rotating the second hand wheel drives the first screw to rotate to move the threaded slide laterally to achieve three-dimensional angle adjustment of the nozzle.

[0007] In one possible design, the mixing assembly includes: Mixing tube; The connecting flange is fixedly installed on one end of the mixing pipe and the connecting pipe, and the two connecting flanges are fixedly connected; An air intake elbow is fixedly connected to one end of the mixing tube, a first groove is formed at one end of the air intake elbow, and an extension pipe is fixedly connected to one end of the air intake elbow; An oil inlet pipe, fixedly connected to the other end of the mixing pipe; An inner elbow, fixedly connected to one end of the oil inlet pipe and extending to the interior of the air intake elbow; The spherical sleeve is fixedly installed at one end of the mixing tube; A hollow truncated cone block is fixedly connected to one end of the inner curved pipe and contacts the second groove of the air intake curved pipe. A plurality of circular holes are formed on the hollow truncated cone block. A partition plate is fixedly connected to the inner wall of the hollow truncated cone block; The conical stopper is fixedly connected between the partitions, and the partitions are provided with rectangular holes; Among them, compressed air enters through the intake elbow, and fuel enters through the oil inlet pipe. After being diverted by the hollow frustum block, they are initially mixed at the circular hole and then accelerated through the rectangular hole.

[0008] In one possible design, it also includes: The arc-shaped piece is fixedly installed on the top inner wall of the connecting pipe; A fixed semicircular plate is fixedly installed on one inner wall of the oil pipe; A rotating rod is rotatably connected between the fixed semicircular plate and the side wall of the oil pipe guide tube; A plurality of rotating blades are fixedly sleeved on the outer wall of the rotating rod; The mixed gas is blocked by the arc-shaped sheet and then drives the rotating blades to rotate, and finally mixes to form atomized fuel for spraying.

[0009] In one possible design, it also includes: The fixed outer cylinder is fixedly installed on the top of the supporting horizontal plate; a third hand wheel, rotatably connected to the top of the fixed outer cylinder; A third screw rod, the thread of which passes through the third hand wheel; A support column, fixedly connected to the top of the third screw rod; The support frame is fixedly installed at the bottom of the axial air duct, and the top of the support column is in conflict with the bottom of the support frame; Among them, rotating the third hand wheel drives the third screw rod to move up and down, and adjusts the inclination of the support frame to assist in stabilizing the nozzle.

[0010] In a possible design, it further includes valves, which are arranged on the intake elbow and the oil inlet pipe; Among them, the valve is used to independently adjust the amount of compressed air and fuel, realizing online adjustment of flame length and stiffness.

[0011] In a possible design, a control component is further included, and the control component includes: The support base is fixedly installed on one side of the top of the rack; The reduction motor is fixedly installed on the support base; Two first rotating shafts rotate and penetrate the interior of the frame; Moving wheels, fixedly connected to both ends of the first rotating shaft; A sprocket is fixedly mounted on the output shaft of the reduction motor and one of the first rotating shafts; The chain and the transmission sleeve are arranged on the outer wall of the sprocket; Among them, the starting reduction motor drives the moving wheel to rotate through the sprocket and chain to realize the overall movement of the device.

[0012] In a possible design, a plurality of limit screws are threadedly connected to the fixed rectangular frame, and one end of each of the limit screws contacts the outer wall of the nozzle; Among them, the limit screw is used to fix the angle of the nozzle to ensure that the nozzle is accurately leveled within the range of ±15°.

[0013] In this application, the central air channel delivers a small amount of high-speed air (approximately 10% of the total primary air volume) during operation, creating a negative pressure zone to stabilize the flame root and prevent pulverized coal from backflowing and clogging the nozzle. This cools the burner tip, preventing high-temperature gas erosion of the nozzle and extending equipment life. It also assists in adjusting the flame shape and reducing NOx generation (by lowering the excess air coefficient in the flame center).

[0014] The pulverized coal is transported by an independent fan through the pulverized coal channel and sprayed into the kiln through a nozzle at a specific diffusion angle. The pulverized coal mixes with the swirling air to form a spiral airflow, promoting the dispersion and atomization of the pulverized coal.

[0015] The swirl air channel uses an axial swirler with long spiral blades to generate strong swirl intensity (swirl number can reach 0.6-1.2), which fully mixes the pulverized coal and air. The swirl air and axial air work together to form an internal recirculation zone, intensifying the combustion reaction.

[0016] The axial flow air channel pipe delivers high-speed DC air (160-250m / s), enveloping the swirling air and coal powder airflow to form a "tight outside and loose inside" flow field structure. It adjusts the degree of flame divergence, controls the flame length and thickness, and adapts to the needs of different kiln types. If the position of the device needs to be adjusted, the reduction motor can be started, and the reduction motor drives the first rotating shaft to rotate through the chain and sprocket, and the first rotating shaft drives the moving wheel to rotate, thereby adjusting the overall position of the device; If the angle of the nozzle needs to be adjusted, and the nozzle can be leveled on an inclined ground, the applicable scope of the lifting device is to turn the first operating hand wheel, the first operating hand wheel drives the second screw rod to rise, and then the fixed rectangular frame is driven to rise by the lifting support plate to adjust the height of the fixed rectangular frame. At this time, the nozzle and the axial air channel tube rotate around the second rotating shaft as a whole, turn the second hand wheel, the second hand wheel drives the first screw rod to rotate, and the first screw rod drives the threaded slide to move horizontally, thereby adjusting the horizontal position of the fixed rectangular frame, and then limit the direction and position of the nozzle and the axial air channel tube by multiple screws on the fixed rectangular frame, turn the third hand wheel, the third hand wheel drives the third screw rod to rise, and the third screw rod drives the support column to rise, and the support column can contact the other end of the support frame, and the position of the support frame is limited again to ensure stability; When the fuel is introduced, it can be mixed with compressed air first. The compressed air is introduced through the air intake elbow, and the fuel is introduced through the oil inlet pipe. The fuel is sent out from the inside of the hollow frustum block and is blocked by the conical block and partition, and is divided into multiple streams. The air is introduced from the gap between the second groove and the inner elbow and is ejected along multiple groups of circular holes to be initially mixed with the fuel. The setting of multiple rectangular holes accelerates the mixing process. By adjusting the valve, the amount of compressed air and the amount of fuel injection can be adjusted according to the flame conditions on site. After the initial mixing, the fuel continues to be discharged through the extension pipe. After being blocked by the spherical sleeve, it is sent into the interior of the connecting pipe along the gap between the mixing pipe and the intake elbow for re-mixing. When passing through the bend of the connecting pipe and the oil pipe duct, it is blocked by the arc plate and can only pass through from the bottom. Since the fixed semicircular plate blocks half of the channel, the fuel pushes multiple rotating blades to rotate around the rotating rod. Only after the final mixing can it be sprayed out, the oil and gas are fully mixed and then sprayed out in an atomized state. The combustion is sufficient, avoiding air pollution. After the pressure is reduced, it is convenient to adjust the flame according to demand. The flame is highly stable, which greatly reduces the erosion of the refractory lining.

[0017] Beneficial effects: Multi-stage air distribution optimizes combustion, and the central air, swirl air, axial air and coal powder channel are independently controlled to form a "tight outside and loose inside" flow field structure, enhance the mixing of coal powder and air, improve the burnout rate, and significantly reduce CO and unburned carbon losses.

[0018] The central wind reduces the excess air coefficient in the center of the flame and inhibits the generation of thermal NOx; the swirl wind and axial wind work together to form an internal recirculation zone, allowing the pulverized coal to burn under oxygen-poor conditions, reducing fuel-type NOx emissions, and the overall emissions are lower than those of traditional burners.

[0019] The three-stage mixing of fuel (primary mixing, secondary mixing and final mixing) is achieved through the hollow frustum block, conical block and rotating blades, which reduces the atomized particle size, ensures complete combustion and avoids the formation of carbon black.

[0020] The height, horizontal position and inclination of the fixed rectangular frame can be adjusted in conjunction with the first, second and third operating handwheels to achieve precise leveling of the nozzle within the range of ±15° to adapt to the inclined kiln body or ground and avoid local overheating of the kiln lining caused by uneven flame burning.

[0021] The reduction motor drives the sprocket chain transmission to achieve rapid movement of the entire device, reduce manual handling costs, and is suitable for multi-kiln switching scenarios.

[0022] When flame stability is improved, the temperature fluctuation range in the kiln is reduced, the erosion of the refractory lining by high-temperature gas is reduced, and the life of the kiln lining is extended.

[0023] The air volume of each channel can be independently controlled by the fan inverter to adapt to changes in coal quality and avoid frequent shutdowns for adjustments.

[0024] The air intake elbow and the oil intake pipe valve are linked to adjust the ratio of compressed air and fuel, realizing online adjustment of flame length and stiffness to meet the requirements of different working conditions of drying and calcining.

[0025] The proportion of primary air is reduced, the heat loss from exhaust gas is reduced, and the coal consumption per ton of clinker is reduced.

[0026] The mixing assembly, adjustment assembly and control assembly can be disassembled and assembled independently, which reduces the replacement time of the mixing tube and improves maintenance efficiency.

[0027] The inner wall of the pulverized coal channel is sprayed with tungsten carbide coating to extend its service life; the rotating blades are made of high-chromium alloy steel (Cr26) to improve wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a three-dimensional structural diagram of a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 2 This is a schematic diagram of the three-dimensional structure of a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention from a second perspective; Figure 3 This is a schematic diagram of the three-dimensional structure of the supporting horizontal plate and the sliding outer cylinder in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 4 This is a schematic diagram of the three-dimensional structure of the oil pipe and mixing pipe in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 5 This is an exploded view of the oil pipe and mixing pipe in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 6 This is a schematic diagram of the three-dimensional cross-sectional structure of an oil pipe in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 7 This is a schematic diagram of the three-dimensional structure of a mixing tube in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 8 This is a schematic diagram of the three-dimensional cross-sectional structure of a mixing tube in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 9 This is a schematic diagram of the three-dimensional cross-sectional structure of the air intake elbow and the inner elbow in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention; Figure 10 This is an exploded view of the air intake elbow and hollow frustum block in a four-channel pulverized coal combustion device with multi-stage air distribution proposed by the present invention.

[0029] In the figure: 1. frame; 2. first rotating shaft; 3. supporting cross plate; 4. nozzle; 5. swirl air channel tube; 6. coal air channel tube; 7. central air channel tube; 8. connecting pipe; 9. oil pipe guide tube; 10. moving wheel; 11. supporting frame; 12. axial air channel tube; 13. second rotating shaft; 14. fixed rectangular frame; 15. reduction motor; 16. supporting base; 17. first operating handwheel; 18. threaded slide; 19. lifting support plate; 20. rotating base; 21. first screw rod; 22. second handwheel; 23. second screw rod; 24. Sliding outer cylinder; 25. Fixed outer cylinder; 26. Third screw rod; 27. Third hand wheel; 28. Connecting flange; 29. ​​Oil inlet pipe; 30. Valve; 31. Inlet elbow pipe; 32. Spherical sleeve; 33. Mixing pipe; 34. Arc-shaped piece; 35. Rotating blade; 36. Rotating rod; 37. Fixed semicircular plate; 38. Inner elbow; 39. Hollow frustum block; 40. Extension pipe; 41. First groove; 42. Second groove; 43. Rectangular hole; 44. Partition; 45. Circular hole; 46. Conical stopper; 47. Support column. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] In one embodiment: Figure 1-10 A combustion device, which uses a frame 1 as the main frame, a fixed support cross plate 3 is welded on the top of the frame, a T-shaped groove is provided on the surface of the support cross plate, and a T-shaped slider matching the groove is welded to the bottom of the sliding outer cylinder 24 to realize horizontal sliding of the sliding outer cylinder on the support cross plate. The top of the sliding outer cylinder is rotatably connected to the first operating hand wheel 17 through a tapered roller bearing. The inner hole of the first operating hand wheel is machined with an M24 thread to form a threaded pair with the second screw rod 23. After the second screw rod 23 passes through the guide hole of the sliding outer cylinder, the bottom plate of the lifting support plate 19 is welded on the top. Horizontal grooves are provided on both side walls of the lifting support plate. The threaded slide 18 realizes horizontal sliding through the slider and the groove. The two ends of the first screw rod 21 are installed on the side walls of the lifting support plate through thrust ball bearings. The second hand wheel 22 is connected to the first screw rod through a flat key. The rotating seat 20 is welded to the top of the threaded slide, and the rotating seat is connected to the bottom of the fixed rectangular frame 14 through a ball joint. The second rotating shaft 13 is installed on the two side walls of the fixed rectangular frame through deep groove ball bearings, the inner ends of the two second rotating shafts are welded to the nozzle 4, and an annular positioning groove is processed on the outer wall of the nozzle. Four M8 limit screws pass through the side walls of the fixed rectangular frame and tighten the positioning groove to achieve the angle positioning of the nozzle.

[0032] Axial air duct 12 is welded to the rear end of nozzle 4. Its inner wall is flanged to swirl air duct 5. A long spiral blade axial cyclone with a 50mm pitch and a swirl number of 0.8 is welded to the inner wall of the swirl air duct. Coal air duct 6 is connected to the swirl air duct via a ceramic fiber gasket. Central air duct 7 utilizes a double-layer stainless steel structure, with the outer layer conveying pulverized coal and the inner layer conveying central air. A support frame 11 is fixedly mounted to the bottom of axial air duct 12, with the top of support column 47 abutting against the bottom of support frame 11. Oil pipe conduit 9 is inserted into the center of the central air duct. Connecting pipe 8 is welded to its rear end. A curved blade 34 with a curvature radius of 1.5 times the pipe diameter is welded to the inner wall of the top of the connecting pipe. A fixed semicircular plate 37 is welded to the side wall of the oil pipe conduit, forming a semi-enclosed channel with the side wall of the oil pipe conduit. A rotating rod 36 is mounted on both ends of the fixed semicircular plate and the side wall of the oil pipe conduit via oil-bearing bearings. Four aluminum alloy rotating blades 35 are welded to the rotating rod.

[0033] The mixing assembly connects the mixing tube 33 to the connecting pipe 8 through two connecting flanges 28. The mixing tube adopts a double-layer sleeve structure, with the outer layer being the air intake elbow 31 and the inner layer being the oil intake pipe 29. An inner elbow 38 is welded to the tail of the oil intake pipe, and a hollow frustum block 39 is welded to the end of the inner elbow. The frustum block has a cone angle of 60° and eight circular holes 45 with a diameter of 3mm on the surface. Four partitions 44 are welded inside the frustum block, and conical blocks 46 with a cone angle of 90° are welded between the partitions. Rectangular holes 43 are provided on the partitions. A second groove 42 is provided on the inner wall of the air intake elbow 31, forming an annular gap with the inner elbow 38. A first groove 41 is provided at the end of the air intake elbow, forming a secondary mixing chamber with the outer wall of the mixing tube 33. Ball valves 30 are respectively installed on the air intake elbow and the oil intake pipe. The valve diameter is consistent with the inner diameter of the pipe. A spherical sleeve 32 is fixedly connected to one end of the mixing tube 33.

[0034] During operation, the central air channel 7 delivers a high-speed airflow accounting for 10% of the total primary air volume, creating a negative pressure zone to stabilize the flame root and cool the nozzle tip. Pulverized coal is delivered by an independent fan to the pulverized coal channel, where it is sprayed into the kiln through a nozzle at a 15° divergence angle. It mixes with the swirl air generated by the swirl air channel 5, which has a swirl number of 0.8, forming a spiral airflow. The axial flow channel 12 delivers high-speed DC air at 160-250 m / s, enveloping the swirl air to create a "tight outside, loose inside" flow field. The flame divergence is controlled by adjusting the axial flow volume. To adjust the device's position, the reduction motor 15 is activated, which drives the moving wheel 10 via a chain drive, allowing the entire device to move. To adjust the nozzle angle, rotating the first operating handwheel 17 raises or lowers the second screw 23, driving the fixed rectangular frame 14 to rotate about the second rotating shaft 13. Rotating the second handwheel 22 rotates the first screw 21, driving the threaded slide 18 to move laterally, achieving three-dimensional angle adjustment of the nozzle. After adjustment, tighten the limit screws to secure the nozzle. During fuel combustion, compressed air enters through the intake elbow 31, and fuel enters through the fuel inlet pipe 29. After being diverted by the hollow truncated cone 39, it initially mixes with air at the circular hole 45. The mixed gas is accelerated by the rectangular hole 43 and enters the secondary mixing chamber. It is then finally mixed by the curved blades 34 and rotating blades 35, forming atomized fuel for spraying. This structure improves the pulverized coal burnout rate, reduces NOx emissions, lowers carbon black generation, keeps flame temperature fluctuations within ±20°C, reduces the annual wear rate of the kiln lining, and shortens equipment relocation time.

[0035] This application can be used in the field of four-channel pulverized coal burners, and can also be used in other fields applicable to this application.

[0036] In another embodiment: Figure 1-10 A four-channel pulverized coal combustion device with multi-stage air distribution is used in the field of four-channel pulverized coal burners. A support seat 16 is welded on the right side of the top of the frame 1, and a reduction motor 15 is installed on the support seat with a motor power of 7.5kW. Two first rotating shafts 2 are installed inside the frame through roller bearings. The distance between the two rotating shafts is 1.2m, and moving wheels 10 are installed at both ends of each rotating shaft. Sprockets are welded to the first rotating shaft on the right and the output shaft of the reduction motor respectively. The sprocket has 24 teeth and is driven by a 40A chain. A fixed outer cylinder 25 is welded to the left side support cross plate 3 of the frame, and a third handwheel 27 is installed on the top of the fixed outer cylinder. The inner hole of the third handwheel is machined with M20 thread to form a thread pair with the third screw rod 26. A support column 47 is welded on the top of the third screw rod, and a polytetrafluoroethylene gasket is pasted on the top of the support column.

[0037] However, as is well known to those skilled in the art, the working principle and wiring method of the reduction motor 15 are conventional means or common knowledge and will not be elaborated here. Those skilled in the art can make any selection according to their needs or convenience.

[0038] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A four-channel pulverized coal combustion device with multi-stage air distribution, characterized in that: include: Rack (1); A nozzle (4) is mounted on the frame (1) with an adjustable angle; An axial flow air channel tube (12) fixedly connected to the nozzle (4); The swirl air channel tube (5) is arranged inside the axial air channel tube (12); The coal air channel tube (6) is arranged inside the swirl air channel tube (5); A central air channel pipe (7) is arranged inside the coal air channel pipe (6); An oil pipe conduit (9) is arranged inside the central air channel tube (7), and one side of the oil pipe conduit (9) is fixedly connected to a connecting pipe (8); An adjustment component for adjusting the angle of the nozzle (4); Mixing assembly, used to mix fuel and air; Among them, the central air channel tube (7) conveys high-speed airflow to stabilize the flame root and cool the nozzle (4), the coal air channel tube (6) conveys coal powder, the swirl air channel tube (5) generates swirl to promote the mixing of coal powder and air, and the axial air channel tube (12) conveys direct air to control the flame shape, forming a flow field structure that is tight outside and loose inside, thereby improving the burnout rate and reducing emissions.

2. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 1 is characterized in that: The adjustment component includes: A sliding outer cylinder (24) is slidably connected to the top of the supporting transverse plate (3), and the supporting transverse plate (3) is fixedly mounted on the top of the frame (1); A first operating hand wheel (17) is rotatably connected to the top of the sliding outer cylinder (24); A second screw rod (23) threadedly penetrates the first operating hand wheel (17) and slides through the sliding outer cylinder (24); A lifting support plate (19) fixedly connected to the top of the second screw rod (23); A first screw rod (21) is rotatably connected between the inner walls of both sides of the lifting support plate (19); A threaded slide (18) is slidably connected to the top of the lifting support plate (19) and is threadedly sleeved on the outer wall of the first screw rod (21); A second hand wheel (22) is fixedly connected to one end of the first screw rod (21); A rotating seat (20) is fixedly mounted on the top of the threaded slide (18); A fixed rectangular frame (14) is rotatably connected to the top of the rotating seat (20), and the inner walls on both sides of the fixed rectangular frame (14) are rotatably connected to the second rotating shaft (13), and the nozzle (4) is fixedly connected to the second rotating shaft (13); The first operating hand wheel (17) is rotated to drive the second screw rod (23) to move up and down to adjust the height of the nozzle (4), and the second hand wheel (22) is rotated to drive the first screw rod (21) to rotate to move the threaded slide (18) laterally, thereby achieving three-dimensional angle adjustment of the nozzle (4).

3. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 1 is characterized in that: The mixing assembly comprises: Mixing tube (33); A connecting flange (28) is fixedly mounted on one end of the mixing pipe (33) and the connecting pipe (8), and the two connecting flanges (28) are fixedly connected; An air intake elbow (31) is fixedly connected to one end of the mixing tube (33), a first groove (41) is formed at one end of the air intake elbow (31), and an extension tube (40) is fixedly connected to one end of the air intake elbow (31); An oil inlet pipe (29) is fixedly connected to the other end of the mixing pipe (33); An inner bend pipe (38) is fixedly connected to one end of the oil inlet pipe (29) and extends into the interior of the air intake bend pipe (31); A spherical sleeve (32) is fixedly mounted on one end of the mixing tube (33); A hollow truncated cone block (39) is fixedly connected to one end of the inner curved pipe (38) and contacts the second groove (42) of the air intake curved pipe (31). A plurality of circular holes (45) are formed on the hollow truncated cone block (39); A partition (44) is fixedly connected to the inner wall of the hollow truncated cone block (39); A conical stopper (46) is fixedly connected between the partitions (44), and a rectangular hole (43) is opened on the partition (44); The compressed air enters through the intake elbow (31), and the fuel enters through the fuel inlet pipe (29). After being diverted by the hollow truncated cone block (39), the compressed air is initially mixed at the circular hole (45), and then the mixing is accelerated through the rectangular hole (43).

4. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 3 is characterized in that: Also includes: An arc-shaped piece (34) is fixedly mounted on the top inner wall of the connecting pipe (8); A fixed semicircular plate (37) is fixedly mounted on an inner wall of one side of the oil pipe guide tube (9); A rotating rod (36) is rotatably connected between the fixed semicircular plate (37) and the side wall of the oil pipe guide tube (9); A plurality of rotating blades (35) are fixedly sleeved on the outer wall of the rotating rod (36); The mixed gas is blocked by the arc-shaped sheet (34) and then drives the rotating blade (35) to rotate, thereby performing final mixing and forming atomized fuel for spraying.

5. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 1 is characterized in that: Also includes: A fixed outer cylinder (25) is fixedly mounted on the top of the supporting horizontal plate (3); A third hand wheel (27) is rotatably connected to the top of the fixed outer cylinder (25); A third screw rod (26), the thread of which passes through a third hand wheel (27); A support column (47) is fixedly connected to the top of the third screw rod (26); A support frame (11) is fixedly mounted on the bottom of the axial air channel tube (12), and the top of the support column (47) is in conflict with the bottom of the support frame (11); The third hand wheel (27) is rotated to drive the third screw rod (26) to move up and down, and the inclination of the support frame (11) is adjusted to assist in stabilizing the nozzle (4).

6. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 3 is characterized in that: It also includes a valve (30), which is arranged on the intake elbow (31) and the oil inlet pipe (29); The valve (30) is used to independently adjust the amount of compressed air and fuel, thereby achieving online adjustment of flame length and stiffness.

7. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 1, characterized in that: Also included are control components, which include: A support base (16) is fixedly mounted on one side of the top of the frame (1); A reduction motor (15) is fixedly mounted on a support base (16); Two first rotating shafts (2) rotate and penetrate the interior of the frame (1); Moving wheels (10) are fixedly connected to both ends of the first rotating shaft (2); A sprocket fixedly sleeved on the output shaft of the reduction motor (15) and one of the first rotating shafts (2); The chain and the transmission sleeve are arranged on the outer wall of the sprocket; The starting reduction motor (15) drives the moving wheel (10) to rotate via the sprocket and the chain, thereby achieving the overall movement of the device.

8. The four-channel pulverized coal combustion device with multi-stage air distribution according to claim 2, characterized in that: A plurality of limit screws are threadedly connected to the fixed rectangular frame (14), and one end of each of the limit screws contacts the outer wall of the nozzle (4); The limit screw is used to fix the angle of the nozzle (4) to ensure that the nozzle (4) is accurately leveled within the range of ±15°.

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