Fine powder separation and conveying device, boiler pulverizing unit and boiler system

Abstract

The application relates to the technical field of boilers, and provides a fine powder separation and conveying device, a boiler powder preparation unit and a boiler system, wherein the fine powder separation and conveying device comprises a fine powder separation part, a first cavity formed by a wall part, a first outlet and a second outlet in communication with the first cavity, the first cavity is used for receiving a gas-solid mixture and separating the gas-solid mixture to obtain spent gas and fine powder, the first outlet is used for outputting the fine powder, and the second outlet is used for outputting the spent gas; the fine powder conveying part is connected with the fine powder separation part, the fine powder conveying part comprises first pipelines and second pipelines in communication with each other, the first pipelines are in communication with the fine powder separation part through the first outlet, are used for receiving the fine powder, and make the fine powder mixed with a first airflow to obtain a uniform flow air-powder mixture; and the second pipelines are used for receiving the uniform flow air-powder mixture, and make the uniform flow air-powder mixture converge with a second airflow and be pushed to a to-be-burned point by the second airflow. The fine powder separation and conveying device can improve the safety and stability of boiler operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of boilers, in particular to a fine powder separation and conveying device, a boiler pulverizing unit and a boiler system. BACKGROUND

[0002] In the field of coal-fired boiler technology, a pulverizing system is usually used to crush and screen coal to obtain coal powder, which is then sent to the boiler for combustion. In a coal-fired boiler, it is necessary to ensure that the coal powder can be continuously, uniformly and stably conveyed, so that the boiler can burn stably and continuously.

[0003] In the prior art, the boiler system, especially the boiler system using a direct-fired pulverizing unit, cannot uniformly mix the wind and the powder, resulting in poor uniformity of the coal powder flow, thereby causing large fluctuations in the combustion flame and affecting the stability and safety of the boiler operation. SUMMARY

[0004] In view of this, the embodiments of the present application provide a fine powder separation and conveying device, a boiler pulverizing unit and a boiler system to improve the uniformity of the wind and powder mixing.

[0005] In a first aspect, the embodiments of the present application provide a fine powder separation and conveying device, comprising: a fine powder separation part, comprising a wall part, a first cavity formed by the wall part, a first outlet and a second outlet in communication with the first cavity, the first cavity being used to receive a gas-solid mixture and separate the gas-solid mixture to obtain a barren gas and a fine powder, the first outlet being used to output the fine powder, and the second outlet being used to output the barren gas; and a fine powder conveying part connected to the fine powder separation part, the fine powder conveying part comprising a first pipeline and a second pipeline in communication with each other, the first pipeline being in communication with the fine powder separation part through the first outlet, used to receive the fine powder and mix the fine powder with a first airflow to obtain a uniform flow wind-powder mixture; and the second pipeline being used to receive the uniform flow wind-powder mixture and push the uniform flow wind-powder mixture to a to-be-combusted point after the uniform flow wind-powder mixture is merged with a second airflow.

[0006] According to the embodiments of the first aspect of the present application, the first pipeline comprises a narrow diameter section and a wide diameter section connected to each other, the radial cross-sectional area of the narrow diameter section being smaller than the radial cross-sectional area of the wide diameter section, so that the first airflow enters the wide diameter section after entering the narrow diameter section and mixes with the fine powder.

[0007] According to the embodiments of the first aspect of the present application, the first pipeline has a first air inlet for introducing the first airflow, and the second pipeline has a second air inlet for introducing the second airflow, the radial cross-sectional area of the first air inlet being smaller than the radial cross-sectional area of the second air inlet.

[0008] According to the embodiments of the first aspect of the present application, further comprising a first air guide pipe connected between the second outlet and the first pipeline and / or the second pipeline, used to guide the barren gas into the fine powder conveying part to make the barren gas as the first airflow and / or the second airflow.

[0009] According to the embodiment of the first aspect of the present application, the powder storage part is connected between the fine powder separation part and the first pipeline, and is used for containing the fine powder.

[0010] According to the embodiment of the first aspect of the present application, the wall part includes a bottom wall and a side wall, the bottom wall has a first end and a second end along the extending direction of the bottom wall, the first end and the second end are connected with the side wall respectively, the height of the first end from the bottom surface is greater than the height of the second end from the bottom surface, and the bottom wall and / or the side wall is installed with the rapping assembly.

[0011] According to the embodiment of the first aspect of the present application, the powder storage part is connected between the fine powder separation part and the first pipeline, and is used for containing the fine powder.

[0012] According to the embodiment of the second aspect of the present application, the second air guide pipe is connected between the second outlet of the fine powder separation and conveying device and the grinding device, and is used for guiding the exhaust air into the grinding device.

[0013] According to the embodiment of the second aspect of the present application, the exhaust air reheating device is connected between the grinding device and the second air guide pipe, and is used for conveying the heated exhaust air to the grinding device.

[0014] According to the embodiment of the first aspect of the present application, the powder storage part is connected between the fine powder separation part and the first pipeline, and is used for containing the fine powder.

[0015] Compared with the prior art, the embodiment of the present application has at least the following beneficial effects:

[0016] The fine powder separation and conveying device provided by the embodiment of the present application separates the non-uniform gas-solid mixture through the fine powder separation part to obtain the fine powder and the exhaust air, and then makes the fine powder mix with the first air flow in the first pipeline. Since the first air flow is easier to control, the mixing of the fine powder and the first air flow can be realized, and a uniform uniform flow powder-air mixture is obtained. The uniform uniform flow powder-air mixture is pushed to the combustion point by the second air flow in the second channel. Through the cooperation of the first pipeline, the second pipeline and the fine powder separation unit, the uniform mixing of the air and the fine powder can be realized, so that the uniform coal powder is conveyed to the boiler, the fluctuation of the combustion flame is reduced, and the safety and stability of the boiler operation are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one embodiment consistent with the present application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 This is a schematic diagram of the fine powder separation and conveying device provided in this application.

[0019] Figure 2 This is a schematic diagram of the structure of a fine powder separation section provided in this application.

[0020] Figure 3 A schematic diagram of the structure of the first air duct provided in this application.

[0021] Figure 4 This is a schematic diagram showing the connection relationship of the boiler pulverizing unit provided in this application.

[0022] Figure label:

[0023] 10. Grinding unit; 20. Coarse powder separation unit; 30. Fine powder separation and conveying unit; 40. Exhaust gas reheating unit; 60. Ignition point;

[0024] 31. Fine powder separation section; 311. Wall section; 312. First cavity; 313. First outlet; 314. Second outlet; 315. Side wall; 316. Bottom wall; 317. First inlet; 318. Vibrating assembly; 32. Fine powder conveying section; 321. First pipe; 321a. Narrow diameter section; 321b. Wide diameter section; 322. First air inlet; 323. Second pipe; 324. Second air inlet; 325. Discharge port; 33. Powder storage section; 34. First air guide pipe; 341. Second inlet; 342. Third outlet; 343. Fourth outlet;

[0025] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0026] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0027] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0028] In the description of the embodiments in this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", and "bottom" are used.

[0029] The orientation or positional relationship indicated by "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0030] In addition, the technical terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0031] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0032] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0033] In the description of the present application, it should be noted that, unless otherwise stated, "above" and "below" include the number, and the meaning of "multiple" in "one or more" is two and two or more.

[0034] In the coal-fired boiler, it is necessary to ensure that the pulverized coal can be continuously, uniformly and stably transported, so as to make the boiler burn stably and continuously.

[0035] The inventors of the present application notice that the mixing uniformity of the wind and the fine powder is poor in the boiler system, which causes the combustion flame to fluctuate greatly, especially in the direct-fired pulverizing unit, because the distance between the outlet of the coal powder separator and the burner is short, and the uniformity of the coal powder flow of each primary air pipe is poor, thereby causing the combustion flame to fluctuate greatly, and affecting the stability and safety of the boiler operation.

[0036] To solve the above problems, the embodiments of the present application provide a fine powder separation and conveying device, a boiler pulverizing unit and a boiler to improve the uniformity of the mixing of the wind and the fine powder, and thereby improve the stability of the combustion of the boiler system. First, the fine powder separation and conveying device provided by the embodiments of the present application is introduced.

[0037] In a first aspect, the embodiments of the present application provide a fine powder separation and conveying device, please refer to Figure 1 The fine powder separation and conveying device 30 includes a fine powder separation part 31, a first outlet 313 and a second outlet 314 in communication with the first outlet 313, and a first cavity 312 formed by a wall part 311, the first cavity 312 being used for receiving a gas-solid mixture and separating the gas-solid mixture to obtain a fine powder and a spent gas, the first outlet 313 being used for outputting the fine powder, and the second outlet 314 being used for outputting the spent gas; a fine powder conveying part 32 connected with the fine powder separation part 31, the fine powder conveying part 32 including a first pipeline 321 and a second pipeline 323 in communication with each other, the first pipeline 321 being in communication with the fine powder separation part 31 through the first outlet 313, used for receiving the fine powder, and mixing the fine powder with a first gas flow to obtain a uniform flow wind-powder mixture; and the second pipeline 323 being used for receiving the uniform flow wind-powder mixture, and making the uniform flow wind-powder mixture converge with a second gas flow and be pushed to a to-be-burned point by the second gas flow.

[0038] The gas-solid mixture refers to a mixture composed of fine powder with small particle size and air. In the field of boiler technology, the fine powder can be a pulverized solid material obtained by crushing a to-be-burned material. For example, the to-be-burned material is coal, the fine powder is coal powder, and the source of the gas-solid mixture can be a mixture obtained by mixing the to-be-burned material crushed by a pulverizing device 10 with primary air or spent gas. The fine powder separation part 31 is used for separating the gas-solid mixture composed of fine powder and air to obtain fine powder and spent gas. The spent gas refers to a gas flow containing no or a small amount of fine powder.

[0039] Specifically, the fine powder separation part 31 includes a wall part 311, a first cavity 312 enclosed by the wall part 311, a first outlet 313 and a second outlet 314 in communication with the first cavity 312. It can be understood that the fine powder separation part 31 also includes a first inlet 317 in communication with the first cavity 312. The gas-solid mixture enters the first cavity 312 through the first inlet 317 and separates inside the first cavity 312. For example, the fine powder in the gas-solid mixture falls downward under the action of gravity and is output through the first outlet 313, and the spent gas in the gas-solid mixture is lighter and is pushed out through the second outlet 314 by the subsequent gas-solid mixture. Other separation methods can also be used inside the first cavity 312 as long as the effect of separating the fine powder from the air is achieved, and the present application is not limited thereto.

[0040] The fine powder conveying part 32 includes a first pipe 321 and a second pipe 323 in communication with each other, wherein the first pipe 321 is in communication with the fine powder separation part 31 through the first outlet 313 for receiving the fine powder and uniformly mixing the fine powder with the first air flow. In order to avoid loss of fine powder, the communication site of the first pipe 321 with the fine powder separation part 31 is located between the inlet and outlet of the first pipe 321, so that the fine powder enters the first pipe 321 at a position between the inlet and outlet of the first pipe 321, and the fine powder mixes with the first air flow in the first pipe 321 after entering the first pipe 321. The first air flow can be air induced by the induced draft fan, or spent gas output by the fine powder separation part 31. The flow rate of the first air flow is more easily adjusted, and the uniform flow of the mixed air and fine powder can be obtained by adjusting the flow rate of the first air flow. When the flow rate of the first air flow is smaller, it is more conducive to obtaining a uniform mixture of air and fine powder.

[0041] The second pipe 323 is used to receive and push the uniform flow of the mixed air and fine powder. The second pipe 323 is in communication with the first pipe 321, and the uniform flow of the mixed air and fine powder can enter the second pipe 323 from the first pipe 321. In order to avoid loss of the uniform flow of the mixed air and fine powder, the communication site of the second pipe 323 with the first pipe 321 is located between the inlet and outlet of the second pipe 323, so that the uniform flow of the mixed air and fine powder enters the second pipe 323 at a position between the inlet and outlet of the second pipe 323. The uniform flow of the mixed air and fine powder mixes with the second air flow after entering the second pipe 323 and is pushed out by the second air flow from the discharge port 325 to the combustion point 60. The combustion point 60 can be a burner, which can be directly pushed to the burner or distributed to the burner through a coal powder distributor. The second air flow can be air induced by the induced draft fan, or spent gas output by the fine powder separation part 31. The flow rate of the second air flow can also be adjusted, and the uniform flow of the mixed air and fine powder is more easily conveyed when the flow rate of the second air flow is larger.

[0042] The fine powder separation and conveying device 30 provided in the application separates the uneven wind and powder mixture through the fine powder separation part 31 to obtain fine powder and exhaust gas, and then mixes the fine powder with the first gas flow in the first pipeline 321. Since the first gas flow is easier to control, the mixing of the fine powder and the first gas flow can be realized, and a uniform and uniform wind and powder mixture is obtained. The uniform and uniform wind and powder mixture is pushed to the waiting combustion point by the second gas flow in the second channel. Through the cooperation of the first pipeline 321, the second pipeline 323 and the fine powder separation unit, the flow rate of the first gas flow is less than that of the second gas flow, which can realize the uniform mixing of the gas flow and the fine powder, and can convey uniform coal powder to the boiler, reduce the fluctuation of the combustion flame, and ensure the safety and stability of the operation of the boiler.

[0043] In some embodiments, the first pipeline 321 includes a narrow diameter section 321a and a wide diameter section 321b connected to each other. The radial cross-sectional area of the narrow diameter section 321a is smaller than that of the wide diameter section 321b, so that the first gas flow enters the wide diameter section 321b after entering the narrow diameter section 321a, and then mixes with the fine powder.

[0044] In the embodiments of the application, the radial cross section is perpendicular to the axis. The fine powder and the first gas flow are mixed in the wide diameter section 321b. On the one hand, the axial cross-sectional area of the wide diameter section 321b is large, which can provide sufficient mixing space for the fine powder and the first gas flow, and is conducive to the full mixing of the fine powder and the first gas flow. On the other hand, the flow rate of the first gas flow will decrease after entering the wide diameter section 321b from the narrow diameter section 321a, which is also conducive to the full mixing of the first gas flow and the fine powder.

[0045] In some embodiments, the first pipeline 321 has a first air inlet 322 for introducing the first gas flow, and the second pipeline 323 has a second air inlet 324 for introducing the second gas flow. The radial cross-sectional area of the first air inlet 322 is smaller than that of the second air inlet 324.

[0046] In the embodiments of the application, the radial cross section is perpendicular to the axis. The first air inlet 322 is used to introduce the first gas flow, and the second air inlet 324 is used to introduce the second gas flow. The cross-sectional area of the first air inlet 322 is smaller than that of the second air inlet 324. When the gas sources of the first gas flow and the second gas flow are the same, for example, the first gas flow and the second gas flow are both exhaust gas from the fine powder separation part 31, the amount of gas source entering the first pipeline 321 is smaller than that entering the second pipeline 323, so that the first pipeline 321 is more suitable for uniform mixing, and the second pipeline 323 is more suitable for conveying.

[0047] In some embodiments, the first gas guide pipe 34 is connected between the second outlet 314 and the first pipeline 321 and / or the second pipeline 323, and is used to guide the exhaust gas into the fine powder conveying part 32 to make the exhaust gas as the first gas flow and / or the second gas flow.

[0048] The first air guide pipe 34 can be connected only between the second outlet 314 of the fine powder separation part 31 and the first pipe 321, so that the exhaust gas output by the second outlet 314 is mixed with the fine powder falling into the first pipe 321 as the first air flow; the first air guide pipe 34 can be connected only between the second outlet 314 of the fine powder separation part 31 and the second pipe 323, so that the exhaust gas output by the second outlet 314 is used as the second air flow to push the uniform flow of the powder mixture into the second pipe 323. The first air guide pipe 34 can also be connected between the second outlet 314 and the first pipe 321 and between the second outlet 314 and the second pipe 323 at the same time, so that part of the exhaust gas is used as the first air flow and part of the exhaust gas is used as the second air flow. For example, please refer to Figure 3 The first air guide pipe 34 can be a tubular structure with a hollow part, and the first air guide pipe 34 has a second inlet 341, a third outlet 342 and a fourth outlet 343 at both ends in the extension direction of the first air guide pipe 34. The second inlet 341 is connected with the second outlet 314 to make the exhaust gas enter the hollow part, one of the third outlet 342 and the fourth outlet 343 is connected with the first air inlet 322, and the other is connected with the second air inlet 324. The first air guide pipe 34 can also be other structures as long as it can realize the introduction of the exhaust gas into the first pipe 321 and the second pipe 323.

[0049] In some embodiments, a powder storage part 33 is further included, which is connected between the fine powder separation part 31 and the first pipe 321, and the powder storage part 33 is used to accommodate the fine powder.

[0050] The powder storage part 33 can receive the output fine powder from the fine powder separation part 31 and deliver the fine powder to the first pipe 321. The powder storage part can temporarily accommodate the fine powder. In some embodiments, a gate mechanism is provided between the powder storage part and the first pipe 321, which can enable the operator to control the output of the fine powder in the powder storage part. When the fine powder needs to be delivered, the operator can control the valve mechanism to open to realize the output of the fine powder. When the material delivery is not needed or the fine powder delivery needs to be stopped due to an accident, the operator can control the valve mechanism to close to stop the output of the fine powder.

[0051] Optionally, the gate mechanism can be a mechanical hand-controlled gate or an electrically controlled gate. In the above technical solution, by providing the gate mechanism between the powder storage part 33 and the first pipe 321, the controllability and safety of the boiler system can be further improved.

[0052] In some embodiments, please refer to Figure 1 and Figure 2The wall portion 311 comprises a bottom wall 316 and a side wall 315, the bottom wall 316 has a first end and a second end along the extending direction of itself, the first end and the second end are connected with the side wall 315 respectively, the height of the first end from the bottom surface is greater than the height of the second end from the bottom surface, and the bottom wall 316 and / or the side wall 315 is installed with a rapping assembly 318.

[0053] The height of the first end from the bottom surface is greater than the height of the second end from the bottom surface, that is, in the working state, the first end is higher than the second end, so that the bottom wall 316 is arranged in a slope structure, and the rapping structure is used to replace the original natural sliding structure. The rapping assembly 318 is used for falling the fine powder in a vibration mode, the running speed of the fine powder separation part 31 is improved, the output of the pulverizing unit is increased by 10% under the same fineness, and meanwhile, by using the rapping structure, the equipment height of the fine powder separation part 31 can be reduced, so that the equipment is more compact and space-saving. Please refer to Figure 1 and Figure 2 The rapping assembly 318 can be located on the bottom wall 316, or on the side wall close to the bottom wall, or can be arranged on the side wall and the bottom wall at the same time. The rapping assembly 318 can have one set or multiple sets, which is not limited in the present application.

[0054] Secondly, please refer to Figure 4 The embodiment of the present application provides a boiler pulverizing unit, which comprises: a grinding device 10 for crushing coal to obtain crushed materials; a coarse powder separation device 20 connected with the grinding device 10, used for separating the crushed materials to obtain fine powder of a preset particle size; and a fine powder separation and conveying device 30 connected with the coarse powder separation device 20, used for obtaining uniform air-powder mixture.

[0055] The grinding device 10 is used for crushing coal to obtain crushed materials. Exemplarily, the grinding device 10 can adopt a coal mill in the prior art, as long as the crushing effect can be met. After the coal is crushed in the grinding device 10, the crushed materials are sent to the coarse powder separation device 20 by primary air or exhaust air.

[0056] The coarse powder separation device 20 is used for receiving and separating the crushed materials to obtain fine powder of a preset particle size. Exemplarily, the coarse powder separation device 20 can adopt a coarse powder separation device 20 in the prior art, as long as the separation effect can be met. The preset particle size means that the particle size of the fine powder matches the combustion requirement of the burner. After the separation of the fine powder in the coarse powder separation device 20, the output is a gas-solid mixture formed by the fine powder and the primary air or the exhaust air.

[0057] In some embodiments, the coarse powder separation device 20 comprises a coarse powder backflow pipe, so that the crushed materials of a larger particle size can return from the coarse powder backflow pipe to the grinding device 10 for further crushing, which is beneficial to fine grinding and easy mixing, so that the combustion is more sufficient.

[0058] The fine powder separation and conveying device 30 receives the gas-solid mixture from the coarse powder separation device 20, separates the inhomogeneous gas-solid mixture through the fine powder separation part 31 to obtain fine powder and spent gas, and then mixes the fine powder with the first gas flow in the first pipeline 321. Since the first gas flow is easier to control, the mixing of the fine powder and the first gas flow can be realized, and a uniform homogeneous flow of the fine powder and the gas flow is obtained. The uniform homogeneous flow of the fine powder and the gas flow is pushed by the second gas flow in the second pipeline 323 and is ready to be burned. Through the cooperation of the first pipeline 321, the second pipeline 323 and the fine powder separation unit, the uniform mixing of the gas and the fine powder can be realized, the uniform coal powder can be conveyed to the boiler, the fluctuation of the combustion flame is reduced, and the safety and stability of the boiler operation are ensured.

[0059] In some embodiments, a second gas guide pipe is further included, which is connected between the second outlet 314 of the fine powder separation and conveying device 30 and the grinding device 10, and is used to guide the spent gas into the grinding device 10.

[0060] The second gas guide pipe can guide the spent gas output by the fine powder separation part 31 into the grinding device 10 to replace part of the primary air. The second gas guide pipe can be a branch of the first gas guide pipe 34, that is, the first gas guide pipe 34 includes at least two branch pipes, for example, three branch pipes. After the spent gas enters from the second inlet 41, three branch pipes are formed, and the spent gas is simultaneously input into the first pipeline 321, the second pipeline 323 and the grinding device 10, respectively. The space can be comprehensively utilized, and the equipment is more compact.

[0061] In some embodiments, a spent gas reheating device 40 is further included, which is connected between the grinding device 10 and the second gas guide pipe, and is used to convey heated spent gas to the grinding device 10.

[0062] The spent gas reheating device can be an independent plug-in heat source, or can be connected with a flue gas unit of the boiler system. The heat of the discharged flue gas is effectively utilized, the heat loss is reduced, and the energy consumption is reduced. The addition of the spent gas reheating device 40 in the boiler system can heat the spent gas. The heated spent gas enters the grinding device 10, which can reduce the temperature drop during the combustion of the boiler system and is conducive to stable combustion. In a third aspect, the present application provides a boiler system, which includes the above-mentioned fine powder separation and conveying device 30 or the above-mentioned boiler grinding unit.

[0063] The boiler system provided in the application comprises the fine powder separation and conveying device 30, the inhomogeneous wind powder mixture is separated by the fine powder separation part 31 to obtain fine powder and spent gas, and then the fine powder is mixed with the first gas flow in the first pipeline 321, so that the fine powder is mixed with the first gas flow to obtain the uniform flow wind powder mixture, and the uniform flow wind powder mixture is pushed to be combusted by the second gas flow in the second channel. Through the cooperation of the first pipeline 321, the second pipeline 323 and the fine powder separation unit, the wind and the fine powder can be uniformly mixed, the uniform coal powder can be conveyed to the boiler, the fluctuation of the combustion flame is reduced, and the safety and stability of the operation of the boiler system are ensured.

[0064] The foregoing summary of the application is not intended to describe every disclosed embodiment or implementation of the application. The example embodiments are illustrated in greater detail below. Throughout this application, guidance is provided by a series of examples that can be used in various combinations. In each instance, the recited list is only representative of a set of combinations, and should not be interpreted as exhaustive.

[0065] The above merely provides the specific implementation of the application, but the protection scope of the application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the application, and these modifications or replacements should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A fine powder separation and conveying device, characterized in that, include: A fine powder separation section includes a wall portion, a first cavity formed by the wall portion, a first outlet and a second outlet communicating with the first cavity, the first cavity being used to receive a gas-solid mixture and separate the gas-solid mixture to obtain exhaust gas and fine powder, the first outlet being used to output the fine powder, and the second outlet being used to output the exhaust gas. A fine powder conveying unit is connected to the fine powder separation unit. The fine powder conveying unit includes a first pipe and a second pipe that are interconnected. The first pipe is connected to the fine powder separation unit through a first outlet and is used to receive the fine powder and mix the fine powder with a first airflow to obtain a uniform air-powder mixture. The second pipe is used to receive the uniform air-powder mixture and, after the uniform air-powder mixture merges with a second airflow, is pushed to the ignition point by the second airflow. The first pipe includes a narrow diameter section and a wide diameter section that are interconnected. The radial cross-sectional area of ​​the narrow diameter section is smaller than that of the wide diameter section, so that after the first airflow enters through the narrow diameter section, it mixes with the fine powder in the wide diameter section.

2. The fine powder separation and conveying device according to claim 1, characterized in that, The first duct has a first air inlet for introducing a first airflow, and the second duct has a second air inlet for introducing a second airflow. The radial cross-sectional area of ​​the first air inlet is smaller than the radial cross-sectional area of ​​the second air inlet.

3. The fine powder separation and conveying device according to claim 1, characterized in that, It also includes a first air guide pipe, which is connected between the second outlet and the first pipe and / or the second pipe, for introducing the exhaust gas into the fine powder conveying section so that the exhaust gas serves as a first airflow and / or a second airflow.

4. The fine powder separation and conveying device according to claim 1, characterized in that, It also includes a powder storage section, which is connected between the fine powder separation section and the first pipe, and is used to contain the fine powder.

5. The fine powder separation and conveying device according to claim 1, characterized in that, The wall includes a side wall and a bottom wall. The bottom wall has a first end and a second end extending along its own direction. The first end and the second end are respectively connected to the side wall. The height of the first end from the bottom surface is greater than the height of the second end from the bottom surface. A vibrating assembly is installed on the bottom wall and / or the side wall.

6. A boiler pulverizing unit, characterized in that, include: Grinding equipment is used to crush coal to obtain crushed materials; A coarse powder separation device, connected to the grinding device, is used to separate the crushed material to obtain fine powder of a preset particle size; The fine powder separation and conveying device according to any one of claims 1-5 is connected to the coarse powder separation device for obtaining a uniformly flowing air-powder mixture.

7. The boiler pulverizing unit according to claim 6, characterized in that, It also includes a second air guide pipe, which is connected between the second outlet of the fine powder separation and conveying device and the grinding device, for introducing the exhaust gas into the grinding device.

8. The boiler pulverizing unit according to claim 7, characterized in that, It also includes a waste gas reheating device, which is connected between the grinding device and the second gas guide pipe, and is used to supply heated waste gas to the grinding device.

9. A boiler system, characterized in that, It includes the fine powder separation and conveying device according to any one of claims 1-5 or the boiler pulverizing unit according to any one of claims 6-8.

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