Device and method for adjusting powder amount of coal mill

Abstract

The invention relates to the technical field of boilers, and discloses a coal mill powder amount adjusting device and method.The device comprises a separator, a hollow mill shell, a hollow outlet distribution channel, a powder feeding pipeline and a baffle, the mill shell, the outlet distribution channel and the powder feeding pipeline are sequentially communicated from bottom to top, and the separator is arranged in an inner cavity of the mill shell; the baffle extends to an inner cavity of the outlet distribution channel from the outer wall of the powder feeding pipeline through the junction of the outlet distribution channel and the powder feeding pipeline, and the insertion depth of the baffle and / or the rotation angle of the baffle are / is adjustable; wherein the insertion depth of the baffle indicates the height from the junction of the outlet distribution channel and the powder feeding pipeline to the baffle and is recorded as h; the rotation angle of the baffle refers to the included angle between the baffle and a certain vertical plane and is recorded as alpha; the number of the powder feeding pipelines is not less than 2. The problem that in the prior art, the concentration deviation of pulverized coal on the combustion side is too large is solved.

Description

Technical Field

[0001] This invention relates to the field of boiler technology, specifically to a coal mill powder quantity adjustment device and method. Background Technology

[0002] In recent years, the proportion of new energy power generation, represented by wind power and photovoltaic power, has been increasing year by year. However, these power sources are highly intermittent, causing significant impacts on the power grid. On the other hand, fast-regulating power sources with peak-shaving functions, such as pumped storage power stations and gas-fired combined cycle power generation, are relatively lagging behind and have small capacities. This makes the problems of grid connection and absorption of new energy units increasingly prominent, affecting the safe and stable operation of the power grid and power quality. Currently, the installed capacity and power generation of thermal power units still dominate. Relying on deep peak-shaving technology of large thermal power units is the fundamental way to solve the problem of the widening peak-valley gap facing the current power system and ensure the grid's absorption of new energy sources such as wind and solar power.

[0003] Under normal operating conditions, the boiler's flue gas temperature, steam temperature, and wall temperature should remain within the design range. However, due to the influence of fuel characteristics, furnace structure, and load fluctuations, these three temperatures often deviate. Thermal power units will operate at low loads for extended periods to meet deep peak-shaving requirements. Under these conditions, excessive deviations in pulverized coal concentration in various pulverized coal feeding pipelines will directly affect the burner's power, the ignition and stable combustion of the airflow, causing flame deflection, furnace wall erosion, and deviations in heat load and air temperature. x Increased emissions can even cause problems such as coking and pipe bursts. According to relevant standards, for medium-speed direct-fired pulverizing systems, the pulverized coal and air should be evenly distributed between the primary air ducts of the burners on the same floor, with an air volume deviation of no more than ±5% and a pulverized coal concentration deviation of no more than ±20%.

[0004] However, existing power plants, under operating conditions, cannot meet this requirement using adjustable orifices in the pulverized coal feed pipes. The fundamental reason is that the air and pulverized coal distribution deviation at the pulverizer outlet into each feed pipe is too large, exceeding the adjustment range of the adjustable orifice, and the orifice can only achieve unidirectional adjustment of air and pulverized coal. Therefore, how to solve the problem of excessive pulverized coal concentration deviation on the combustion side is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention provides a coal mill powder quantity adjustment device and method, which solves the problems of excessive coal powder concentration deviation on the combustion side in the prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A coal mill powder quantity adjustment device includes a separator, a hollow mill shell, a hollow outlet distribution channel, a powder feeding pipe, and a baffle. The mill shell, outlet distribution channel, and powder feeding pipe are connected sequentially from bottom to top. The separator is located inside the internal cavity of the mill shell. The baffle extends from the outer wall of the powder feeding pipe through the junction of the outlet distribution channel and the powder feeding pipe to the internal cavity of the outlet distribution channel. The insertion depth and / or rotation angle of the baffle are adjustable. The insertion depth of the baffle refers to the height from the junction of the outlet distribution channel and the powder feeding pipe to the baffle, denoted as h. The rotation angle of the baffle refers to the angle between the baffle and a vertical plane, denoted as α. The number of powder feeding pipes is ≥2.

[0007] The beneficial effects of the present invention are: by adjusting the insertion depth and / or rotation angle of the baffle, the present invention changes the flow trajectory of the air-coal airflow, reduces the coal powder concentration deviation between each coal feeding pipe of the mill, effectively balances the operating power of the burners corresponding to each coal feeding pipe, and ensures the safe and stable operation of the thermal power unit.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] As a preferred technical solution, it includes an electric control device connected to the baffle.

[0010] The advantages of adopting the above-mentioned further solution are: it facilitates the adjustment of the insertion depth and / or rotation angle of the baffle through electric control, making operation convenient and highly automated.

[0011] As a preferred technical solution, a manual adjustment device connected to an electric control device is included.

[0012] The beneficial effect of adopting the above-mentioned further solution is that when the electric control device malfunctions, the on-site construction personnel can rotate the manual adjustment device to adjust the insertion depth and / or rotation angle of the baffle as an emergency measure.

[0013] As a preferred technical solution, the electric control device includes two motors, which are used to control the insertion depth h of the baffle and the rotation angle α of the baffle, respectively.

[0014] The advantages of adopting the above-mentioned further solution are: the two motors control the insertion depth and rotation angle of the baffle respectively, which facilitates simultaneous operation and improves operational efficiency.

[0015] As a preferred technical solution, the rotation angle α of the baffle is in the range of 45°~135°.

[0016] The beneficial effect of adopting the above-mentioned further scheme is that it can significantly impede the airflow of the powder and achieve a better adjustment effect.

[0017] As a preferred technical solution, an airtight device is provided at the junction of the outlet distribution channel, the powder feeding pipe, and the baffle.

[0018] The beneficial effect of adopting the above-mentioned further solution is to ensure that the air-powder airflow does not overflow from the junction of the outlet distribution channel, the powder delivery pipe, and the baffle.

[0019] As a preferred technical solution, the inner wall of the baffle is provided with wear-resistant metal and / or ceramic plates.

[0020] The beneficial effect of adopting the above-mentioned further solutions is to increase the service life of the baffle.

[0021] As a preferred technical solution, the outlet distribution channel includes a transition section and a vertical section, with the mill shell, transition section, vertical section, and powder feeding pipeline connected sequentially from bottom to top.

[0022] The beneficial effects of adopting the above-mentioned further scheme are: the gradual section of the outlet distribution channel reduces the airflow velocity and weakens the inertial separation effect of pulverized coal; the vertical section uses gravity settling to promote homogenization and reduce the rotational momentum of air and pulverized coal. The two work together to improve the uniformity of pulverized coal distribution, reduce pipe wear and resistance, and ensure the combustion stability of the boiler.

[0023] As a preferred technical solution, the insertion depth h ranges from 0.3H to H; where H represents the height of the vertical segment.

[0024] The beneficial effect of adopting the above-mentioned further scheme is that it can have a greater impact on the airflow of powder and achieve a better adjustment effect.

[0025] A method for adjusting the coal mill powder quantity, using the aforementioned coal mill powder quantity adjustment device, includes the following steps: S1, the air-powder airflow spirals upward inside the mill shell, and the coal powder particle size is classified by the separator to form the initial air-powder distribution. The air-powder airflow enters each powder feeding pipeline through the outlet distribution channel. S2, if at least one of the relative deviations in coal powder concentration between a certain coal powder feeding pipe and the other coal powder feeding pipes is greater than a set threshold, then the depth and / or rotation angle of the baffle is adjusted; after adjustment, the air-coal powder airflow rotates in the outlet distribution channel and collides with the baffle, and then the air-coal powder airflow is guided to the other coal powder feeding pipes.

[0026] The beneficial effects of this invention are as follows: By installing a baffle at the connection between the outlet distribution channel and the pulverized coal feeding pipe, and by installing an airtight device between the outlet distribution channel and the baffle, and between the baffle and the pulverized coal feeding pipe, leakage of the air-powder airflow is prevented during adjustment. By controlling the electric control device or adjusting the manual control device, the insertion depth and / or rotation angle of the baffle in the mill are changed, increasing the probability of collision between the air-powder airflow and the wall in the outlet distribution channel, thereby changing the flow trajectory of the air-powder airflow. At this time, the air-powder airflow will flow into the other pulverized coal feeding pipes, which greatly alleviates the problem of pulverized coal concentration in a single pulverized coal feeding pipe, resulting in better uniformity of pulverized coal concentration entering each burner. This invention can effectively solve the problem of excessive pulverized coal concentration deviation in each pulverized coal feeding pipe of the mill, adjusting the pulverized coal concentration deviation between the pulverized coal feeding pipes of the mill to a specified range, and effectively balancing the operating power of the burners corresponding to each pulverized coal feeding pipe.

[0027] Compared with the prior art, the present invention has the following advantages: (1) By adjusting the insertion depth and / or rotation angle of the baffle, the present invention changes the flow trajectory of the air-powder airflow, reduces the coal powder concentration deviation between each coal powder feeding pipe of the mill, effectively balances the operating power of the burners corresponding to each coal powder feeding pipe, and ensures the safe and stable operation of the thermal power unit. (2) The present invention facilitates the adjustment of the insertion depth and / or rotation angle of the baffle through electric control, making it easy to operate and highly automated. (3) In the event of a malfunction in the electric control device, the on-site construction personnel can rotate the manual adjustment device to adjust the insertion depth and / or rotation angle of the baffle as an emergency measure. (4) The two motors of the present invention control the insertion depth and rotation angle of the baffle respectively, which facilitates simultaneous operation and has high operating efficiency; (5) The present invention can significantly impede the airflow of powder and achieve a better adjustment effect; (6) This invention ensures that the air-powder airflow will not overflow from the junction of the outlet distribution channel, the powder delivery pipe, and the baffle; (7) This invention increases the service life of the baffle; (8) The gradual section of the outlet distribution channel of the present invention reduces the airflow velocity and weakens the inertial separation effect of pulverized coal; the vertical section uses gravity settling to promote homogenization and reduce the rotation momentum of air and pulverized coal. The two work together to improve the uniformity of pulverized coal distribution, reduce pipe wear and resistance, and ensure the combustion stability of the boiler. Attached Figure Description

[0028] Figure 1 A front view of a coal mill powder quantity adjustment device provided by the present invention; Figure 2 A top view of a coal mill powder quantity adjustment device provided by the present invention; Figure 3 This is a partial structural schematic diagram of a coal mill powder quantity adjustment device provided by the present invention; Figure 4 This is a schematic diagram illustrating the relative position and adjustment method of the baffle and the coal feeding pipe in a coal mill powder quantity adjustment device provided by the present invention.

[0029] The labels and their corresponding names in the attached diagram: 1-Separator, 2-Mill shell, 3-Outlet distribution channel, 4-Coal drop pipe, 5-Powder feeding pipe, 6-Airtight device, 7-Fixed bracket, 8-Baffle, 9-Electric control device, 10-Manual adjustment device, 11-Electric control device bracket, 31-Gradual transition section, 32-Vertical section. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0031] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] Example 1 like Figures 1 to 4 As shown, this invention discloses a coal mill powder quantity adjustment device for adjusting the powder quantity at the outlet of the coal mill separator. It includes a separator 1 (preferably a static separator 1), a mill casing 2, an outlet distribution channel 3 (preferably, the outlet distribution channel 3 includes a transition section 31 and a vertical section 32, with the mill casing 2, transition section 31, vertical section 32, and powder delivery pipe 5 connected sequentially from bottom to top), a powder delivery pipe 5, an airtight device 6 (preferably an annular airtight device 6, such as a sealing ring), a baffle 8, a fixed bracket 7 (for fixing the baffle 8), an electric control device 9, a manual adjustment device 10 (preferably a structure composed of a manual adjustment handwheel and a screw), and an electric control device bracket 11 (for supporting the electric control device 9). When the air-powder airflow collides with the baffle 8, it changes the air-powder airflow trajectory, and the air-powder airflow flows into the remaining powder delivery pipe 5 in a swirling manner. This invention also provides a method for adjusting the powder quantity during operation. The coal mill powder quantity adjustment device proposed in this invention controls the insertion depth and / or rotation angle of the baffle 8 by configuring an electric control device 9, so as to achieve uniform delivery of coal powder fuel and balance the pressure in the powder delivery pipeline. It can effectively solve the problems of excessive coal powder concentration deviation in each powder pipe and unbalanced burner power in traditional coal mills.

[0033] A coal mill powder quantity adjustment device is disclosed. This device can effectively solve the problem of excessive coal powder concentration deviation in each powder pipe of the mill, adjust the coal powder concentration deviation between each powder feeding pipe 5 of the mill to a specified range, and effectively balance the operating power of the burners corresponding to each powder feeding pipe 5.

[0034] The present invention is achieved using the following technical solution: A coal mill powder quantity adjustment device includes a separator 1 and a mill casing 2, and sequentially connected components such as an outlet distribution channel 3, a coal drop pipe 4, a powder feeding pipe 5, an airtight device 6, a fixed support 7, a baffle 8, an electric control device 9, a manual adjustment device 10, and an electric control device support 11. The baffle 8 is located between the powder feeding pipe 5 and the outlet distribution channel 3 and is connected by the airtight device 6.

[0035] A further improvement of the present invention is that the baffle 8 is connected to the outer wall of the powder feeding pipe 5 by a fixed bracket 7.

[0036] A further improvement of the present invention is that the baffle 8 is a 90° arc plate with a radius slightly larger than that of the powder feeding pipe 5.

[0037] A further improvement of the present invention is that the insertion depth of the baffle 8 can be adjusted by an electric control device 9 for adjusting the distance.

[0038] A further improvement of the present invention is that the rotation angle of the baffle 8 can be adjusted by an electric control device 9 for adjusting the position.

[0039] A further improvement of the present invention is that wear-resistant ceramic layers are provided on both the outer and inner walls of the baffle 8.

[0040] A further improvement of the present invention is that a manual adjustment device 10 is provided to ensure normal operation when the electric control device 9 malfunctions.

[0041] A further improvement of the present invention is that the number of outlet powder feeding pipes 5 is the same as the number of baffle 8 adjustment devices.

[0042] Furthermore, the parts of the baffle 8 that come into contact with the airflow are covered with wear-resistant metal or ceramic sheets to increase the service life of the baffle 8.

[0043] Furthermore, the electric control device 9 is equipped with two motors, which respectively control the insertion depth and rotation angle of the baffle 8.

[0044] Furthermore, during the adjustment process, the current insertion depth and rotation angle of the baffle 8 in the mill can be obtained from the adjustment scale connected to the electric control device 9 in the central control room, making the adjustment of the insertion depth and / or rotation angle more controllable and quantifiable.

[0045] Furthermore, the rotation angle α of the baffle 8 is set to 45° to 135°, which can significantly impede the airflow of the powder, and achieves the best effect when the rotation angle is 90°.

[0046] Furthermore, the insertion depth h of the baffle 8 is set to 0~H, which can have a significant impact on the airflow of the powder, and can achieve better results when the insertion depth is 0.3H~H.

[0047] This invention provides a coal mill pulverizer powder adjustment device. A baffle is installed at the connection between the outlet distribution channel and the pulverizer feeding pipe. An airtight device is installed between the outlet distribution channel and the baffle, and between the baffle and the pulverizer feeding pipe, preventing leakage of the air-powder airflow during adjustment. By controlling an electric control device or adjusting a manual control device, the insertion depth and / or rotation angle of the baffle within the mill are changed, increasing the probability of collision between the air-powder airflow and the wall in the outlet distribution channel, thereby altering the air-powder airflow trajectory. At this time, the air-powder airflow flows into the remaining pulverizer feeding pipes, greatly alleviating the problem of pulverized coal concentration in a single feeding pipe and resulting in better uniformity of pulverized coal concentration entering each burner.

[0048] Example 2 like Figures 1 to 4 As shown, as a further optimization of Embodiment 1, this embodiment also includes the following technical features based on Embodiment 1: This invention provides a coal mill powder quantity adjustment device to achieve uniform coal powder fuel delivery and balance the power of the burners corresponding to each powder delivery pipeline.

[0049] Implementation method: This invention provides a coal mill powder quantity adjustment device, comprising a separator 1, a mill outer shell 2, an outlet distribution channel 3, a coal drop pipe 4, a powder delivery pipe 5, an airtight device 6, a fixed support 7, a baffle 8, an electric control device 9, a manual adjustment device 10, and an electric control device support 11. The separator 1 is located inside the mill and connected to the mill outer shell 2. The mill outer shell 2 is connected to the separator outlet distribution channel 3, which is connected to the powder delivery pipe 5. The fixed support 7 is connected to the baffle 8, which is connected to the electric control device 9. The electric control device 9 is connected to the electric control device support 11, which is connected to the manual adjustment device 10. The electric control device support 11 is connected to the mill outer shell 2. Preferably, the center of the outlet distribution channel 3 is connected to the coal drop pipe 4. This has the advantage that the symmetrical diffusion of coal powder forms a uniform flow field, reducing the coal powder concentration deviation in each powder delivery pipe 5 from the source, while also reducing pipe wall wear and airflow disturbance. However, the coal entry method is not limited to entering through the coal drop pipe 4.

[0050] The air-powder airflow spirals upward within the mill, reaching the top of the intermediate frame (not shown in the figure). It is then classified by separator 1 to form the initial air-powder distribution. The air-powder airflow enters the powder delivery pipe 5 through the outlet distribution channel 3. If at least one of the relative deviations in pulverized coal concentration between a certain powder delivery pipe 5 and the others exceeds a set threshold, the depth and / or rotation angle of the baffle 8 is adjusted via the electric control device 9. As the air-powder airflow rotates within the outlet distribution channel 3, it collides with the baffle 8. Under the influence of this rotation, the air-powder airflow is guided to the remaining powder delivery pipes 5, reducing the pulverized coal concentration deviation and pulverized coal mass flow rate in those pipes, thereby reducing the concentration deviation between each pipe and maintaining the dynamic balance of the burner power. Because the baffle 8 is directly eroded by the air-powder airflow, this invention provides an anti-wear ceramic layer on the wall surface of the baffle 8.

[0051] A more specific implementation example is as follows: In the four coal feeding pipes 5, each coal feeding pipe 5 has at least one baffle 8. If the relative deviation of the coal powder concentration between a certain coal feeding pipe 5 and the other coal feeding pipes 5 is greater than ±10%, then the coal powder concentration needs to be adjusted. By adjusting the depth and / or rotation angle of the baffle 8 at the coal feeding pipe 5, the coal powder concentration in the high-concentration coal feeding pipe 5 is reduced and the coal powder concentration in the low-concentration coal feeding pipe 5 is increased, while maintaining the air volume deviation in each coal feeding pipe 5 basically unchanged (air volume deviation controlled within ±5%), and finally achieving the coal powder concentration deviation between each coal feeding pipe controlled within ±10%.

[0052] Because there is a gap fit between the baffle 8, the outlet distribution channel 3, and the powder delivery pipe 5, an airtight device 6 needs to be installed at the connection of the three to ensure that the air and powder flow will not overflow from the connection.

[0053] In this invention, a manual adjustment device 10 is provided. When the electric control device 9 malfunctions, the on-site construction personnel can rotate the adjustment handwheel to adjust the insertion depth and / or rotation angle of the baffle 8 as an emergency measure.

[0054] This invention addresses the problems of excessive coal powder concentration deviation and burner power imbalance in traditional coal mills by proposing a coal powder quantity adjustment device. By adjusting the insertion depth and / or rotation angle of the baffle, the flow trajectory of the air-coal airflow is changed, reducing the coal powder concentration deviation between the coal powder supply pipes 5 of the mill, effectively balancing the operating power of the burners corresponding to each coal powder supply pipe, and ensuring the safe and stable operation of the thermal power unit.

[0055] As described above, the present invention can be implemented well.

[0056] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0061] All features disclosed in all embodiments of this specification, or steps in all methods or processes implied in the disclosure, may be combined and / or extended or replaced in any way, except for mutually exclusive features and / or steps.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Based on the technical essence of the present invention, any simple modifications, equivalent substitutions, and improvements made to the above embodiments within the spirit and principles of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A coal mill powder quantity adjustment device, characterized in that, The system includes a separator (1), a hollow mill shell (2), a hollow outlet distribution channel (3), a powder feeding pipe (5), and a baffle (8). The mill shell (2), the outlet distribution channel (3), and the powder feeding pipe (5) are connected sequentially from bottom to top. The separator (1) is located inside the internal cavity of the mill shell (2). The baffle (8) extends from the outer wall of the powder feeding pipe (5) through the junction of the outlet distribution channel (3) and the powder feeding pipe (5) to the internal cavity of the outlet distribution channel (3). The insertion depth and / or the rotation angle of the baffle (8) are adjustable. The insertion depth of the baffle (8) refers to the height from the junction of the outlet distribution channel (3) and the powder feeding pipe (5) to the baffle (8), denoted as h. The rotation angle of the baffle (8) refers to the angle between the baffle (8) and a certain vertical plane, denoted as α. The number of powder feeding pipes (5) is ≥2.

2. The coal mill powder quantity adjustment device according to claim 1, characterized in that, Includes an electric control device (9) connected to the baffle (8).

3. The coal mill powder quantity adjustment device according to claim 2, characterized in that, Includes a manual adjustment device (10) connected to an electric control device (9).

4. The coal mill powder quantity adjustment device according to claim 2, characterized in that, The electric control device (9) includes two motors, which are used to control the insertion depth h of the baffle (8) and the rotation angle α of the baffle (8), respectively.

5. The coal mill powder quantity adjustment device according to claim 1, characterized in that, The rotation angle α of the baffle (8) ranges from 45° to 135°.

6. The coal mill powder quantity adjustment device according to claim 1, characterized in that, It includes an airtight device (6) located at the junction of the outlet distribution channel (3), the powder delivery pipe (5), and the baffle (8).

7. The coal mill powder quantity adjustment device according to claim 1, characterized in that, The inner wall of the baffle (8) is provided with wear-resistant metal and / or ceramic plates.

8. A coal mill powder quantity adjustment device according to any one of claims 1 to 7, characterized in that, The outlet distribution channel (3) includes a transition section (31) and a vertical section (32). The mill shell (2), the transition section (31), the vertical section (32), and the powder feeding pipe (5) are connected sequentially from bottom to top.

9. A coal mill powder quantity adjustment device according to claim 8, characterized in that, The insertion depth h ranges from 0.3H to H; where H represents the height of the vertical segment (32).

10. A method for adjusting the powder quantity of a coal mill, characterized in that, The coal mill powder quantity adjustment device according to any one of claims 1 to 9 is used to adjust the coal mill powder quantity. Includes the following steps: S1, the air-powder airflow spirals upward inside the mill shell (2), and the coal powder particle size is classified by the separator (1) to form the initial air-powder distribution. The air-powder airflow enters each powder delivery pipe (5) through the outlet distribution channel (3). S2, if at least one of the relative deviations in coal powder concentration between a certain coal powder conveying pipe (5) and the other coal powder conveying pipes (5) is greater than the set threshold, then adjust the depth and / or rotation angle of the baffle (8); after adjustment, the air-coal powder airflow rotates in the outlet distribution channel (3) and collides with the baffle (8), and then the air-coal powder airflow is guided to the other coal powder conveying pipes (5).

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