A flow guide device for a coal mill inlet duct

Abstract

The application discloses a kind of flow guide devices of coal mill inlet air duct, it is related to the field of coal mill, including cold air pipe and hot air pipe, the cold air pipe is connected with hot air pipe diametrically in the vortex shell both sides with the diameter of cold air pipe and hot air pipe twice, the center of the bottom end of vortex shell inside is fixedly connected with the air guide cone of tip end upward, the upper portion of vortex shell is connected with connecting pipe, the inlet of cold air pipe and hot air pipe is all provided with transverse air uniformizing plate and longitudinal air uniformizing plate, the inlet of connecting pipe and hot air pipe is all provided with temperature detection probe on the bottom end, the inner wall of the bottom end of connecting pipe is provided with air pressure sensor, the side wall of connecting pipe is connected with control box, the baffle pivot rotationally connected on the inner wall of connecting pipe, and all are fixedly connected with half-round baffle.The application has the purpose of efficiently mixing cold air and hot air, and it is convenient for staff to control the inflowing gas flow, to achieve the purpose of convenient control of air volume.

Description

Technical Field

[0001] This invention relates to the field of coal mills, specifically to a flow guiding device for the inlet air duct of a coal mill. Background Technology

[0002] A coal mill is a device that crushes and grinds coal into pulverized coal. It is widely used in the production of pulverized coal in industries such as power, metallurgy, building materials, and chemicals. For different types of coal, such as anthracite, bituminous coal, and lignite, the outlet temperature of the coal mill needs to be controlled within different ranges. The outlet temperature of the coal mill is mainly controlled by controlling the primary air temperature at the inlet of the coal mill. The primary air at the inlet of the coal mill is a mixture of hot and cold primary air. The inlet temperature of the primary air at the inlet of the coal mill is adjusted by regulating the mixing ratio of cold and hot primary air.

[0003] Existing coal mill inlet air duct diversion devices mostly set the cold air pipe and hot air pipe orthogonally, so that the cold air and hot air are mixed in the mixing chamber and then output to the coal mill through the output pipe. However, the existing air duct diversion devices do not have an air duct structure for efficient mixing of hot air and cold air, resulting in uneven mixing of cold air and hot air. Furthermore, there is no good way to monitor the temperature and gas flow in the air duct, and it is not possible to intuitively understand and control the situation inside the air duct from the outside. It is also difficult to conveniently control the air pressure and airflow temperature inside the air duct. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a flow diversion device for the inlet air duct of a coal mill, so as to solve the technical problems of uneven mixing of cold and hot air in existing coal mill inlet air duct flow diversion devices, and the lack of a good way to monitor the temperature and gas flow rate in the air duct.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a flow guiding device for the inlet air duct of a coal mill, comprising a cold air duct and a hot air duct, wherein the cold air duct and the hot air duct are connected opposite to each other on both sides of a volute shell with a diameter twice the diameter of the cold air duct and the hot air duct, respectively; a guide cone with its tip pointing upward is fixedly connected to the center of the bottom end of the volute shell; a connecting pipe is connected to the top of the volute shell; a transverse air distribution plate and a longitudinal air distribution plate are provided at the inlet of both the cold air duct and the hot air duct; a temperature detection probe is provided at the bottom end of the connecting pipe and at the inlet of the hot air duct; a wind pressure sensor is provided on the inner wall of the bottom end of the connecting pipe; a control box is connected to the side wall of the connecting pipe; and a display is provided in the control box away from the connecting pipe. The device includes a screen and control buttons, and has an internal controller. A mounting plate is welded to the outer wall of the connecting pipe, and a motor is mounted on the mounting plate. The output end of the motor is connected to a reduction gearbox, and the output end of the reduction gearbox is connected to an output shaft. The output shaft extends into the connecting pipe and is rotatably connected to the inner wall of the connecting pipe. Both ends of the output shaft inside the connecting pipe are fixedly connected to driving teeth. One side of the driving teeth meshes with a set of driven teeth, and the other side meshes with transmission teeth. The other side of the transmission teeth meshes with another set of driven teeth. A baffle plate shaft is connected to the center of both sets of driven teeth. The baffle plate shaft is rotatably connected to the inner wall of the connecting pipe, and a semi-circular baffle plate is fixedly connected to each of these shafts.

[0006] By adopting the above technical solution, the purpose of efficiently mixing cold and hot air is achieved, which makes it easier for staff to control the flow rate of the incoming gas and to conveniently control the air volume of the outgoing air.

[0007] The present invention is further configured such that the cold air pipe is provided with a cold air duct facing the inside of the vortex shell, the hot air pipe is provided with a hot air duct facing the inside of the vortex shell, and a mixing air duct is provided above the center of the vortex shell.

[0008] By adopting the above technical solution, hot air flows from the hot air pipe into the vortex shell through the hot air duct, and cold air flows from the cold air pipe into the vortex shell through the cold air duct. Both the cold air and the hot air are guided by the air guide cone at the center of the vortex shell and the inner wall of the vortex shell, and rotate and rise inside the vortex shell. During the rotation process in the vortex shell and the mixing duct, they are efficiently and fully mixed.

[0009] The present invention is further configured such that the wind pressure sensor, the temperature detection probe, and the motor are all connected to the control box via wires.

[0010] By adopting the above technical solution, the wire connection can ensure the stability of signal transmission.

[0011] The present invention is further configured such that an arc-shaped protective plate is provided below the output shaft of the connecting pipe.

[0012] By adopting the above technical solution, the arc-shaped guard plate can prevent the wind in the air duct from affecting the output shaft transmission structure.

[0013] The present invention is further configured such that the connecting pipe is provided with a wind deflector limiting ring on the rotation radius of the two sets of wind deflectors, and the wind deflector limiting ring and the arc-shaped guard plate are on the same plane.

[0014] By adopting the above technical solution, the wind deflector limiting ring can prevent the wind deflector from rotating excessively.

[0015] The invention is further configured such that the motor is fixed to the mounting plate by a motor bracket, and the gearbox is provided with mounting feet on both sides and is fixed to the mounting plate by screws in conjunction with the mounting feet.

[0016] By adopting the above technical solution, the motor bracket can stably fix the motor, and the screws can stably fix the gearbox to the mounting plate.

[0017] The present invention is further configured such that a power cord is connected to the bottom of the control box, a control box power supply is provided inside the control box, and the power cord is connected to the control box power supply inside the control box.

[0018] By adopting the above technical solution, the control box power supply provides power to the control box.

[0019] The present invention is further configured such that the vortex housing and the connecting pipe are connected by bolts.

[0020] By adopting the above technical solution, the connecting pipe can be easily disassembled for repair after a failure of the internal components.

[0021] The present invention is further configured such that the top end of the connecting pipe, the inlet of the cold air pipe, and the edge of the inlet of the hot air pipe are all provided with connecting holes.

[0022] By adopting the above technical solution, it is convenient to connect the connecting pipe to the coal mill, and to connect the cold air pipe and the hot air pipe to the corresponding air guide pipe.

[0023] The present invention is further configured such that the radius of the semicircle of the wind deflector is smaller than the radius of the connecting pipe and larger than the radius of the inner diameter of the wind deflector limiting ring.

[0024] By adopting the above technical solution, the wind deflector can efficiently regulate airflow.

[0025] In summary, the present invention has the following main beneficial effects:

[0026] 1. This invention achieves efficient mixing of cold and hot air by setting the cold air inlet pipe and the hot air inlet pipe to be offset from each other, setting a vortex structure at the interaction point of cold and hot air, and setting an upward-pointing air guide cone in the middle of the vortex. After the cold and hot air enter the vortex, they are fully rotated and mixed before being output upward through the mixing air pipe. This prevents the uneven temperature of the airflow entering the coal mill from damaging the coal mill.

[0027] 2. This invention installs multiple sets of monitoring devices for the gas inside the pipeline and sets up a control panel on one side of the connecting pipe above the vortex shell. The staff can conveniently understand the gas information at various points in the pipeline through the display screen on the control panel, which facilitates the staff to control the flow rate of the incoming gas.

[0028] 3. This invention provides a wind deflector that is controlled by a motor to rotate and open above the mixing pipe. The air volume of the mixed air can be conveniently controlled by the control buttons on the control panel, thus achieving the purpose of convenient control of the air volume.

[0029] 4. This invention, by setting up combined longitudinal and transverse air distribution plates in the cold air duct and the hot air duct, allows the airflow to enter the vortex shell evenly, ensuring that the airflow can be fully and efficiently mixed inside the vortex shell. Attached Figure Description

[0030] Figure 1 This is a top internal view of the present invention;

[0031] Figure 2 For the present invention Figure 1 Enlarged view of A in the middle;

[0032] Figure 3 This is a frontal internal view of the present invention;

[0033] Figure 4 For the present invention Figure 3 Enlarged view of B in the middle;

[0034] Figure 5 This is a front view of the present invention;

[0035] Figure 6 For the present invention Figure 5 Enlarged view of C in the middle;

[0036] Figure 7 This is a top view of the present invention;

[0037] Figure 8 This is a front view of the transverse air distribution plate of the present invention;

[0038] Figure 9 This is a front view of the longitudinal air distribution plate of the present invention;

[0039] Figure 10 This is a top view of the windbreak structure of the present invention;

[0040] Figure 11 For the present invention Figure 10 Enlarged view of D;

[0041] Figure 12 This is a schematic diagram of the windshield transmission structure of the present invention.

[0042] In the diagram: 1. Cold air duct; 2. Hot air duct; 3. Cold air duct; 4. Hot air duct; 5. Air guide cone; 6. Vortex; 7. Mixing duct; 8. Longitudinal air distribution plate; 9. Lateral air distribution plate; 10. Temperature detection probe; 11. Connecting pipe; 12. Control box; 13. Controller; 14. Power cord; 15. Control box power supply; 16. Control buttons; 17. Display screen; 18. Wind pressure sensor; 19. Mounting plate; 20. Motor bracket; 21. Motor; 22. Gearbox; 23. Output shaft; 24. Baffle shaft; 25. Arc-shaped guard plate; 26. Driving gear; 27. Transmission gear; 28. Driven gear; 29. ​​Baffle limit ring; 30. Baffle. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] The embodiments of the present invention will now be described.

[0045] A flow diversion device for the inlet air duct of a coal mill, such as Figures 1-12As shown, the system includes a cold air duct 1 and a hot air duct 2. The cold air duct 1 and hot air duct 2 are connected opposite each other to the two sides of a vortex shell 6, whose diameter is twice the diameter of the cold air duct 1 and hot air duct 2, respectively. A guide cone 5 with its pointed tip pointing upwards is fixedly connected to the center of the bottom of the vortex shell 6. Hot air flows from the hot air duct 2 into the vortex shell 6 through the hot air duct 4, while cold air flows from the cold air duct 1 into the vortex shell 6 through the cold air duct 3. Both the cold and hot air are guided by the guide cone 5 at the center of the vortex shell 6 and the inner wall of the vortex shell 6, rotating and rising within the vortex shell 6. During this rotation within the vortex shell 6 and the mixing duct 7, they are efficiently and thoroughly mixed, avoiding uneven mixing of the cold and hot air. A connecting pipe 11 is connected to the top of the vortex shell 6. A horizontal air distribution plate 9 and a vertical air distribution plate 8 are installed at the inlets of both the cold air duct 1 and the hot air duct 2. The louvered structure of the horizontal air distribution plate 9, located at the inlet of the cold air duct 1 and the hot air duct 2, enables the airflow to flow evenly laterally, while the louvered structure of the vertical air distribution plate 8 enables the airflow to flow evenly longitudinally. The horizontal and vertical air distribution plates 9 work together to maintain a uniform airflow within the cold air duct 1 and the hot air duct 2 before entering the vortex 6. Temperature detection probes 10 are installed at the bottom of the connecting pipe 11 and at the inlet of the hot air duct 2. A wind pressure sensor 18 is installed on the inner wall of the bottom of the connecting pipe 11. A control box 12 is connected to the side wall of the connecting pipe 11. The control box 12 has a display screen 17 and control buttons 16 located away from the connecting pipe 11, and a controller 13 is installed inside. A mounting plate 19 is welded to the outer wall of the connecting pipe 11. A motor 21 is installed, and a reduction gearbox 22 is connected to the output end of the motor 21. An output shaft 23 is connected to the output end of the reduction gearbox 22. The output shaft 23 extends into the connecting pipe 11 and is rotatably connected to the inner wall of the connecting pipe 11. Both ends of the output shaft 23 inside the connecting pipe 11 are fixedly connected to driving teeth 26. One side of the driving teeth 26 is engaged with a set of driven teeth 28, and the other side is engaged with a transmission tooth 27. The other side of the transmission tooth 27 is engaged with another set of driven teeth 28. The center of each set of driven teeth 28 is connected to a baffle plate shaft 24, which is rotatably connected to the inner wall of the connecting pipe 11 and is fixedly connected to a semi-circular baffle plate 30. Temperature detection probes 10, located at the inlet of the hot air pipe 2 and at the bottom of the connecting pipe 11, can respectively... The temperature of the airflow flowing into the volute 6 from the hot air duct 2 and the temperature of the mixed air flowing in the mixing duct 7 are detected. The air pressure sensor 18 can detect the gas flow velocity in the mixing duct 7 and display it intuitively on the display screen 17, making it easy for staff to understand the situation inside the duct. The staff controls the motor 21 to rotate through the control button 16. The output shaft of the motor 21 is reduced in speed and increased in torque through the reduction gearbox 22, causing the output shaft 23 connected to the output end of the reduction gearbox 22 to rotate. When the output shaft 23 rotates, the driven gear 28 on one side and the transmission gear 27 on the other side rotate in opposite directions through the driving gear 26 fixedly connected at both ends. The rotation of the transmission gear 27 drives the driven gear 28 that is not meshing with the driving gear 26 to rotate in the same direction as the driven gear 28 that is meshing with the driving gear 26.This achieves the goal of simultaneously rotating the baffle shaft 24 in the same direction, thereby simultaneously controlling the opening amplitude of the baffles 30 on both sides of the arc-shaped guard plate 25, and thus conveniently controlling the gas flow rate output to the coal mill.

[0046] Please see Figure 1 The cold air duct 1 is connected to the vortex shell 6 via a cold air duct 3, and the hot air duct 2 is connected to the vortex shell 6 via a hot air duct 4. A mixing duct 7 is located above the center of the vortex shell 6. Hot air flows from the hot air duct 2 into the vortex shell 6 through the hot air duct 4, and cold air flows from the cold air duct 1 into the vortex shell 6 through the cold air duct 3. Both the cold and hot air are guided by the air guide cone 5 at the center of the vortex shell 6 and the inner wall of the vortex shell 6. They rotate and rise inside the vortex shell 6, and are efficiently and thoroughly mixed during the rotation process within the vortex shell 6 and the mixing duct 7.

[0047] Please see Figure 3 The connecting pipe 11 is equipped with a baffle limiting ring 29 on the rotation radius of the two sets of baffles 30. The baffle limiting ring 29 and the arc-shaped guard plate 25 are on the same plane. The baffle limiting ring 29 can prevent the baffles 30 from rotating excessively. The vortex shell 6 is connected to the connecting pipe 11 by bolts. If the internal components of the connecting pipe 11 fail, the connecting pipe 11 can be easily disassembled for maintenance. The radius of the semicircle of the baffle 30 is smaller than the radius of the connecting pipe 11 and larger than the radius of the inner diameter of the baffle limiting ring 29, so that the baffle 30 can efficiently regulate the airflow.

[0048] Please see Figure 4 The bottom of the control box 12 is connected to a power cord 14. A control box power supply 15 is installed inside the control box 12. The power cord 14 is connected to the control box power supply 15 inside the control box 12. The control box power supply 15 supplies power to the control box 12.

[0049] Please see Figure 6 The motor 21 is fixed to the mounting plate 19 by the motor bracket 20. The gearbox 22 is provided with mounting feet on both sides and is fixed to the mounting plate 19 by screws. The motor bracket 20 can stably fix the motor 21, and the screws can stably fix the gearbox 22 to the mounting plate 19.

[0050] Please see Figure 12 The connecting pipe 11 is provided with an arc-shaped guard plate 25 below the output shaft 23. The arc-shaped guard plate 25 can prevent the wind in the air duct from affecting the transmission structure of the output shaft 23.

[0051] Please see Figure 1 and Figure 3The wind pressure sensor 18, the temperature detection probe 10, and the motor 21 are all connected to the control box 12 via wires. The wire connection ensures the stability of signal transmission. The top of the connecting pipe 11, the inlet of the cold air pipe 1, and the edge of the inlet of the hot air pipe 2 are all provided with connection holes, which facilitates the connection of the connecting pipe 11 to the coal mill, and the connection of the cold air pipe 1 and the hot air pipe 2 to the corresponding air guide pipes.

[0052] The working principle of this invention is as follows: Hot air flows from the hot air pipe 2 through the hot air duct 4 into the vortex shell 6, and cold air flows from the cold air pipe 1 through the cold air duct 3 into the vortex shell 6. Both the hot and cold air are guided by the air guide cone 5 at the center of the vortex shell 6 and the inner wall of the vortex shell 6, rotating and rising within the vortex shell 6. During the rotation process within the vortex shell 6 and the mixing duct 7, they are efficiently and thoroughly mixed, avoiding uneven mixing of the cold and cold air. The louvered structure of the transverse air distribution plate 9 at the inlet of the cold air pipe 1 and the hot air pipe 2 enables the airflow to flow evenly laterally, and the louvered structure of the longitudinal air distribution plate 8 enables the airflow to flow evenly longitudinally. The transverse air distribution plate 9 and the longitudinal air distribution plate 8 work together to ensure that the airflow in the cold air pipe 1 and the hot air pipe 2 enters the vortex shell 6 in a uniform flow state. The temperature detection probes 10 located at the inlet of the hot air pipe 2 and the bottom of the connecting pipe 11 can respectively detect the temperature of the airflow flowing into the vortex shell 6 from the hot air pipe 2 and the temperature of the airflow. The temperature of the mixed air flowing in the mixing duct 7 is detected by the air pressure sensor 18, which can detect the gas flow velocity at the mixing duct 7 and display it intuitively on the display screen 17, making it easy for the staff to understand the situation inside the duct. The staff controls the motor 21 to rotate through the control button 16. The output shaft of the motor 21 is decelerated through the reduction gearbox 22, which reduces the speed and increases the torque, causing the output shaft 23 connected to the output end of the reduction gearbox 22 to rotate. When the output shaft 23 rotates, the driven gear 28 on one side and the transmission gear 27 on the other side rotate in opposite directions through the active gear 26 fixedly connected at both ends. The rotation of the transmission gear 27 drives the driven gear 28 that is not meshed with the active gear 26 to rotate with the driven gear 28 that is meshed with the active gear 26, so as to achieve the purpose of rotating the wind baffle shaft 24 in the same direction at the same time. This achieves the goal of simultaneously controlling the opening range of the wind baffles 30 on both sides of the arc-shaped guard plate 25, thereby conveniently controlling the gas flow rate output to the coal mill.

[0053] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the invention, but such modifications, substitutions, and variations are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A flow guiding device for the inlet air duct of a coal mill, comprising a cold air duct (1) and a hot air duct (2), characterized in that: The cold air duct (1) and the hot air duct (2) are connected to opposite sides of a vortex shell (6) with a diameter twice that of the cold air duct (1) and the hot air duct (2). A guide cone (5) with its tip pointing upward is fixedly connected to the center of the bottom of the vortex shell (6). A connecting pipe (11) is connected to the top of the vortex shell (6). A horizontal air distribution plate (9) and a vertical air distribution plate (8) are provided at the inlet of both the cold air duct (1) and the hot air duct (2). Temperature detection probes (10) are provided at the bottom of the connecting pipe (11) and at the inlet of the hot air duct (2). A wind pressure sensor (18) is provided on the inner wall of the bottom of the connecting pipe (11). A control box (12) is connected to the side wall of the connecting pipe (11). A display screen (17) and control buttons (16) are provided in the control box (12) away from the connecting pipe (11), and a controller (13) is provided inside the control box (12). The outer wall is welded with a mounting plate (19), on which a motor (21) is mounted. The output end of the motor (21) is connected to a gearbox (22), and the output end of the gearbox (22) is connected to an output shaft (23). The output shaft (23) extends into the connecting pipe (11) and is rotatably connected to the inner wall of the connecting pipe (11). Both ends of the output shaft (23) inside the connecting pipe (11) are fixedly connected with driving teeth (26). One side of the driving teeth (26) is engaged with a set of driven teeth (28), and the other side is engaged with a transmission tooth (27). The other side of the transmission tooth (27) is engaged with another set of driven teeth (28). The center of both sets of driven teeth (28) is connected to a baffle plate shaft (24). The baffle plate shaft (24) is rotatably connected to the inner wall of the connecting pipe (11), and both are fixedly connected with a semi-circular baffle plate (30).

2. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The cold air duct (1) is provided with a cold air duct (3) facing the inside of the vortex shell (6), the hot air duct (2) is provided with a hot air duct (4) facing the inside of the vortex shell (6), and a mixing duct (7) is provided above the center of the vortex shell (6).

3. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The wind pressure sensor (18), temperature detection probe (10), and motor (21) are all connected to the control box (12) via wires.

4. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The connecting pipe (11) is provided with an arc-shaped guard plate (25) below the output shaft (23).

5. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The connecting pipe (11) is provided with a baffle limiting ring (29) on the rotation radius of the two sets of baffles (30), and the baffle limiting ring (29) and the arc-shaped guard plate (25) are on the same plane.

6. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The motor (21) is fixed on the mounting plate (19) by the motor bracket (20), and the gearbox (22) is provided with mounting feet on both sides and is fixed on the mounting plate (19) by screws in conjunction with the mounting feet.

7. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The bottom of the control box (12) is connected to a power cord (14), and a control box power supply (15) is provided inside the control box (12). The power cord (14) is connected to the control box power supply (15) inside the control box (12).

8. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The vortex shell (6) and the connecting pipe (11) are connected by bolts.

9. The flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: Connection holes are provided at the top of the connecting pipe (11), the inlet of the cold air pipe (1), and the edge of the inlet of the hot air pipe (2).

10. A flow guiding device for the inlet air duct of a coal mill according to claim 1, characterized in that: The radius of the semicircle of the wind deflector (30) is smaller than the radius of the connecting pipe (11) and larger than the radius of the inner diameter of the wind deflector limiting ring (29).

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