Flue and gas cleaning system

Abstract

This utility model relates to the field of gas purification technology, and in particular to the design of a flue and a gas purification system. The flue extends along a first direction and connects the outlet of an air preheater to the inlet of a dust collector. The flue includes a flue body and an ash discharge device and / or an ash blowing device connected to the flue body. The flue provided in this application extends along a first direction and connects the outlet of an air preheater to the inlet of a dust collector. By setting up an ash discharge device and / or an ash blowing device, combined with dynamic and static dust removal methods, the dust removal efficiency at the bottom of the flue is significantly improved, so as to flexibly cope with complex operating conditions such as unit load changes and start-up and shutdown, and prevent emission fluctuations caused by instantaneous dust rising.

Description

Technical Field

[0001] This utility model relates to the field of gas purification technology, and in particular to a flue and a gas purification system. Background Technology

[0002] With the rapid development of new energy sources, coal-fired power units are transitioning from traditional baseload power sources to flexible adjustable power sources, requiring deep peak-shaving capabilities, i.e., stable operation at 30%-40% or even lower loads. This low-load operation places higher demands on power plant equipment and processes, especially in terms of pollutant control. During low-load operation, fuel and air volumes decrease significantly, leading to a reduction in flue gas mass flow rate. Simultaneously, the flue gas temperature decreases, further resulting in a significant reduction in flue gas volume flow rate. Taking a 600MW coal-fired unit as an example, the flue gas volume at full load is approximately 2 million standard cubic meters per hour, while at 30% load, it drops to 700,000-900,000 standard cubic meters per hour, a decrease of 55%-60%.

[0003] The reduction in flue gas velocity directly weakens its dust-carrying capacity, especially in the horizontal flue from the air preheater outlet to the dust collector inlet. A large amount of dust settles and accumulates at the bottom of the duct, reducing the flow area and thus affecting the flue gas flow characteristics. When the load increases, the flue gas flow rate increases rapidly, and the flue gas velocity rises. The previously deposited dust is re-entrained and enters the dust collector with the flue gas. Because this process occurs instantaneously, the electrostatic precipitator cannot respond in time, causing the inlet dust concentration to more than double in a short period, resulting in excessive outlet dust concentration and affecting environmental emission standards. Therefore, existing coal-fired units face a relatively serious problem of instantaneous dust exceeding standards during low-load operation, and there is an urgent need to optimize system design or operating strategies to address this deficiency. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a flue and gas purification system.

[0005] In a first aspect, embodiments of this application provide a flue extending along a first direction for connecting the outlet of an air preheater with the inlet of a dust collector; the flue includes: a flue body and an ash discharge device and / or an ash blowing device connected to the flue body.

[0006] In conjunction with the first aspect, the ash discharge device includes:

[0007] The top of the ash hopper is connected to the bottom of the flue body, and the ash hopper has a symmetrical structure along the central axis; the top end face size of the ash hopper is larger than the bottom end face size.

[0008] The ash unloading device has its top end connected to the bottom of the ash hopper via a connecting pipe, and its bottom end connected to the ash hopper inside the dust collector via an ash conveying pipe.

[0009] Valves are installed on connecting pipelines.

[0010] In conjunction with the first aspect, the top end face dimension of the ash hopper is 80%-10% of the dimension of the flue body along the second direction; the inclination angle of the ash hopper from top to bottom is 65°-75°;

[0011] The second direction is on the same horizontal plane as the first direction and is perpendicular to each other.

[0012] In conjunction with the first aspect, there are at least two ash hoppers, which are spaced apart along the first direction.

[0013] In conjunction with the first aspect, the dust removal device includes:

[0014] The hood body is located at the bottom of the flue body;

[0015] The air supply duct is located on the lower side of the flue body, with one end connected to the air source and the other end extending into the air cap body;

[0016] The air supply vent is located on the main body of the vent cap and is in the opposite direction to the airflow inside the flue.

[0017] In conjunction with the first aspect, the hood body has multiple air supply holes, which are spaced apart.

[0018] In conjunction with the first aspect, there are multiple hood bodies, which are spaced apart along the first and second directions.

[0019] In conjunction with the first aspect, an air valve is installed on the air supply duct.

[0020] Secondly, this application also provides a gas purification system, including the flue as described above.

[0021] In conjunction with the second aspect, it also includes a control unit, which is connected to the valve corresponding to the ash discharge device and / or the air valve corresponding to the ash blowing device.

[0022] The flue and gas purification system provided in this application, wherein the flue extends along a first direction and is used to connect the outlet of the air preheater and the inlet of the dust collector; the flue includes: a flue body and an ash discharge device and / or an ash blowing device connected to the flue body.

[0023] The flue provided in this application extends along a first direction to connect the outlet of the air preheater and the inlet of the dust collector. By setting up an ash discharge device and / or an ash blowing device, combined with dynamic and static dust removal methods, the dust removal efficiency at the bottom of the flue is significantly improved, so as to flexibly cope with complex operating conditions such as unit load changes, start-up and shutdown, and prevent emission fluctuations caused by instantaneous dust rising.

[0024] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description, claims, and drawings.

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the flue structure provided in Example 2;

[0028] Figure 2 This is a schematic diagram of the flue structure provided in Example 3;

[0029] Figure 3 This is a top view of the hood itself;

[0030] Figure 4 This is a side view of the hood body;

[0031] Figure 5 This is a schematic diagram of the flue structure provided in Example 4.

[0032] Figure label:

[0033] 1-Fluorisendust body, 2-Ash discharge device, 21-Ash hopper, 22-Ash unloading device, 23-Valve, 24-Connecting pipeline, 3-Ash blowing device, 31-Wind cap body, 32-Air supply pipeline, 33-Air supply hole, 34-Air valve. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] To facilitate understanding of this embodiment, the application scenarios and design concepts of this application embodiment will be briefly introduced below.

[0036] In existing technologies, most dust removal systems are designed for a single function and lack dynamic adjustment capabilities, making it difficult to adapt to the changing load operation requirements of the unit; dust removal operations rely on manual intervention and have a low degree of automation; dust emission control is unstable and easily causes fluctuations in the concentration at the dust collector inlet, affecting environmental performance.

[0037] Based on this, this application provides a flue and gas purification system.

[0038] Example 1

[0039] This application provides a flue extending along a first direction for connecting the outlet of an air preheater and the inlet of a dust collector. The flue includes: a flue body 1 and an ash discharge device 2 and / or an ash blowing device 3 connected to the flue body 1.

[0040] In this embodiment, by connecting the flue body 1 with the ash discharge device 2 and / or the ash blowing device 3, the ash accumulation at the bottom of the flue can be reduced by actively discharging the ash or blowing the ash inside the flue body 1. This avoids the impact of ash accumulation on the flue gas volume flow rate and the impact on the electrostatic precipitator when the load increases, which is beneficial to improving the overall purification effect of the gas purification system.

[0041] The flue body 1 extends along the first direction, forming a flue gas flow channel between the air preheater outlet and the dust collector inlet. The flue body 1 is made of conventional high-temperature resistant and corrosion-resistant materials to adapt to the high-temperature and high-humidity flue gas environment of coal-fired power plants.

[0042] To address the dust deposition problem caused by the decrease in flue gas velocity in traditional horizontal flue sections, this flue innovatively introduces the following two auxiliary devices:

[0043] The ash discharge device 2 is connected to the bottom of the flue body 1 and is used to actively discharge the deposited dust from the flue, preventing dust accumulation from affecting the flue gas flow area and the performance of subsequent dust removal equipment. The ash blowing device 3 is connected to the flue body 1 and can blow gas (such as compressed air or steam) into the flue before load changes or during operation to blow up the deposited dust and carry it away with the flue gas, preventing it from being instantly carried into the dust collector and causing excessive emissions when the load increases.

[0044] In this way, by exhausting and / or purging, dust accumulation in the flue is effectively reduced, flue gas velocity is maintained stably, and a large amount of accumulated ash is prevented from being rolled up into the dust collector during load changes, ensuring that the electrostatic precipitator can respond in a timely manner and preventing dust from exceeding the standard.

[0045] The flue with the above structure is suitable for deep peak shaving conditions of coal-fired units, ensuring that environmental emission indicators meet the standards and improving the overall stability and reliability of the gas purification system.

[0046] Example 2

[0047] In this embodiment, the flue body 1 is connected to the ash discharge device 2, combined with Figure 1 As shown.

[0048] In conjunction with the first aspect, the ash discharge device 2 includes: ash hopper 21, ash discharge device 22, and valve 23.

[0049] The top of the ash hopper 21 is connected to the bottom of the flue body 1, and the ash hopper 21 has a symmetrical structure along the central axis; the top end face size of the ash hopper 21 is larger than the bottom end face size.

[0050] The top of the ash unloading device 22 is connected to the bottom of the ash hopper 21 via the connecting pipe 24, and the bottom end is collected and transported to the ash hopper inside the dust collector via the ash conveying pipe.

[0051] Valve 23 is located on connecting pipe 24.

[0052] Understandably, the top of the ash hopper 21 is connected to the bottom of the flue body 1, ensuring that the deposited dust in the flue body 1 can fall smoothly into the ash hopper 21. Furthermore, the ash hopper 21 is symmetrical along its central axis, which helps the dust settle evenly under gravity, reducing localized accumulation problems. In addition, the top end face of the ash hopper 21 is larger than the bottom end face, forming an inverted conical structure, further optimizing dust flow characteristics and preventing blockages.

[0053] The top of the ash discharge device 22 is connected to the bottom of the ash hopper 21 via a connecting pipe 24, used to transport the dust in the ash hopper outwards. The bottom is connected to the ash hopper inside the dust collector via an ash conveying pipe, allowing the discharged dust to be recycled back to the original dust collection system without additional processing. This device can operate periodically or continuously according to operational needs, maintaining the cleanliness of the flue system. A valve 23 is installed on the connecting pipe 24 to control the flow of dust from the ash hopper 21 to the ash discharge device 22. When cleaning is required, the valve 23 is opened, and the dust enters the ash discharge device via the connecting pipe; during non-cleaning periods, the valve 23 is closed to maintain the system's sealing and normal operation.

[0054] It is evident that the ash discharge device 2, through the reasonable configuration of the ash hopper 21, the ash discharge device 22, and the valve 23, achieves effective collection and directional emission of dust in its structure, providing reliable technical support for solving the problem of instantaneous dust exceeding the standard caused by low-load operation of coal-fired units.

[0055] In conjunction with the first aspect, the top end face dimension of the ash hopper is 80%-10% of the dimension of the flue body along the second direction; the inclination angle of the ash hopper from top to bottom is 65°-75°.

[0056] The second direction is on the same horizontal plane as the first direction and is perpendicular to each other.

[0057] In this embodiment, the top end face dimension of the ash hopper 21 is 80%-10% of the dimension of the flue body 1 along the second direction (i.e., the horizontal direction perpendicular to the first extension direction of the flue), preferably 80% of the dimension of the flue body 1 along the second direction (i.e., the width of the flue body 1). This ensures that the top opening of the ash hopper can effectively cover the bottom area of ​​the flue, making it easier for deposited dust to fall into the ash hopper and reducing the risk of dust retention. At the same time, this proportional design also avoids the problem of an excessively large ash hopper affecting the overall layout and support structure of the flue.

[0058] The tilt angle of the ash hopper 21 from top to bottom is set at 65°-75°, preferably 70°. This ensures smooth dust flow while maintaining the compactness of the ash hopper structure, improving space utilization and guaranteeing continuous and stable downward dust flow, thus preventing local blockages from affecting the dust removal effect. Furthermore, because of the high flue gas velocity, a larger tilt angle and greater depth of the ash hopper 21 are more effective in preventing secondary dust re-entrainment and carryover of dust within the ash hopper 21 due to flue gas flow.

[0059] In summary, the ash hopper 21 helps to improve the control of ash accumulation in the flue, thereby further improving the operating performance of the electrostatic precipitator under variable load conditions and reducing the risk of fluctuations in environmental emissions.

[0060] In this embodiment, the first direction is typically the length direction of the flue body 1 (i.e., the horizontal direction shown in the figure), and the second direction is the width direction of the flue body 1. The third direction, perpendicular to the plane containing the first and second directions, is the height direction of the flue body 1. Based on the length of the flue body 1, one, two, or more ash hoppers 21 can be provided.

[0061] In conjunction with the first aspect, there are at least two ash hoppers 21, which are spaced apart along the first direction.

[0062] In this application, the design of the ash discharge device has been further optimized to improve the efficiency and uniformity of flue ash removal. Specifically, this multi-ash hopper 21 structure ensures that the effective collection range of dust deposited in the flue body 1 covers the entire bottom area, avoiding local ash accumulation dead zones. Multiple ash hoppers 21 are rationally distributed along the length of the flue body 1, allowing dust to fall into the hoppers nearby, reducing the possibility of dust accumulation at the bottom of the flue. This multi-point arrangement effectively prevents dust accumulation and improves the cleanliness inside the flue. The spaced arrangement of the ash hoppers 21 helps maintain the uniformity of flue gas flow within the flue body 1, reducing dust settling problems caused by local eddies. When the load changes or operating conditions fluctuate, multiple ash hoppers work together to improve the overall cleaning efficiency of the system, maintaining stable cleaning capacity under different load conditions and ensuring controllable dust concentration at the dust collector inlet.

[0063] Example 3

[0064] In this embodiment, the flue body 1 is connected to the ash blowing device 3, combined with Figure 2 As shown.

[0065] In conjunction with the first aspect, the dust removal device 3 includes: a hood body 31, an air supply duct 32, and an air supply hole 33.

[0066] The hood body 31 is located at the bottom of the flue body 1.

[0067] The air supply duct 32 is located on the lower side of the flue body 1, with one end connected to the air source and the other end extending into the wind cap body 31.

[0068] The air supply hole 33 is opened on the wind cap body 31 and is opposite to the airflow direction in the flue body 1.

[0069] In this embodiment, the purpose of the dust removal device 3 is to actively blow gas to lift the dust deposited at the bottom of the flue body 1 and carry it away with the flue gas, thereby preventing fluctuations in the dust concentration at the dust collector inlet due to dust accumulation when the load changes. The gas generated by the air source is delivered to the air cap body 31 through the air supply pipe 32 and output through the air supply hole 33. The air outlet direction of the air supply hole 33 is opposite to the flue gas flow direction in the flue body 1, forming a reverse blowing effect. This reverse blowing method can effectively enhance the dust disturbance effect, making it easier for the deposited dust to be carried into the main flue gas flow and discharged, avoiding the problem of dust re-settling in a short time due to direct downstream blowing.

[0070] In this way, starting the purging device before the unit load increases can remove the accumulated ash in the flue body 1 in advance, preventing it from being instantly drawn into the dust collector and causing instantaneous exceedances. This provides strong technical support for solving the problem of flue ash accumulation during low-load operation of coal-fired power plants, and helps to ensure the stable operation of the electrostatic precipitator and compliance with environmental emission standards.

[0071] In conjunction with the first aspect, there are multiple air supply holes 33 on the hood body 31, and the multiple air supply holes 33 are arranged at intervals.

[0072] The hood body 31 is provided with multiple air outlets 33, combined with Figure 3 , Figure 4 As shown, these air supply holes 33 are distributed on the surface of the wind cap body 31 with a certain density and layout. The arrangement of multiple air supply holes 33 can achieve a wider airflow coverage area and improve the uniformity of dust blowing at the bottom of the flue body 1.

[0073] The multiple air supply holes 33 are arranged at intervals to ensure that the gas ejected from each air supply hole 33 can effectively act on the dust deposited inside the flue body 1, while avoiding mutual interference between airflows. This interval arrangement can also prevent the flue body 1 from vibrating or wearing due to excessive airflow in local areas.

[0074] In conjunction with the first aspect, there are multiple hood bodies 31, and the multiple hood bodies 31 are arranged at intervals along the first direction and the second direction.

[0075] In this application, in order to further improve the disturbance and removal effect of the dust purging device on the bottom of the flue body 1, and at the same time ensure the uniformity of the flow field distribution in the flue, multiple wind cap bodies 31 are arranged at intervals along the first direction (i.e. the extension direction of the flue body 1) and the second direction (the horizontal direction perpendicular to the first direction). This multi-point distribution in two-dimensional direction can achieve a more comprehensive coverage area and ensure that the dust deposited at the bottom of the flue body 1 is effectively removed.

[0076] The method of spacing along the first direction can avoid dead corners of dust accumulation caused by the lack of purging in local areas, and at the same time facilitates segmented control and maintenance; the method of spacing along the second direction (i.e. the width direction of the flue body 1) is used for wider flue structures, which can significantly enhance the dust removal ability on both sides and the middle area of ​​the flue and prevent dust from lateral accumulation.

[0077] In conjunction with the first aspect, an air valve 34 is installed on the air supply duct 32.

[0078] In this application, in order to further enhance the controllability and flexibility of the dust purging device 3, so that it can adapt to different operating conditions and achieve on-demand dust removal, an air valve 34 is added to the air supply pipeline 32 to control the opening and closing of the gas flow. The air valve 34 can be installed at an appropriate position near the air source or the air cap body 31 to achieve precise control of the air supply process.

[0079] Specifically, when not purging, the closed damper 34 effectively prevents flue gas from flowing back into the air supply duct, protecting the air source equipment. Therefore, the presence of damper 34 helps isolate the air source during maintenance, improving the safety and convenience of equipment maintenance.

[0080] Example 4

[0081] In this embodiment, the flue body 1 is connected to the ash discharge device 2 and the ash blowing device 3, combined with Figure 5 As shown, the main function of the ash discharge device 2 is to directly collect and discharge the dust deposited at the bottom of the flue body 1 to the outside, which is used to solve the problem of continuous dust accumulation during long-term operation and can be used as a basic dust removal method. The ash blowing device 3 actively disturbs the dust deposited at the bottom of the flue through gas blowing, so that it is resuspended and enters the dust collector with the main flue gas flow. It is suitable for preventing the problem of instantaneous dust concentration fluctuation when the unit is operating under variable load and is a dynamic dust removal method.

[0082] In actual operation, the ash discharge device 2 and the ash blowing device 3 can be used together to form a "static + dynamic" composite dust removal strategy. For example, during normal operation, the ash discharge device 2 mainly relies on continuous cleaning of most of the dust at the bottom of the flue; during load changes or pre-start preparation, the ash blowing device 3 is activated to perform pre-cleaning operations to prevent dust from suddenly rising due to load changes.

[0083] In this embodiment, the connection structure between the flue body 1 and the ash discharge device 2 and the ash blowing device 3 not only achieves efficient dust removal but also enhances the system's flexibility and reliability through the synergistic effect of the two devices. This design is particularly suitable for the environmentally stable operation requirements of coal-fired power plants under complex operating conditions such as deep peak shaving and frequent load changes, and has significant technological innovation and engineering application value.

[0084] Secondly, this application also provides a gas purification system, including the flue as described above.

[0085] In conjunction with the second aspect, it also includes a control unit, which is connected to the valve corresponding to the ash discharge device and the air valve corresponding to the ash blowing device.

[0086] The gas purification system provided in this application embodiment not only includes the optimized flue body and its supporting ash discharge device 2 and ash blowing device 3, but also introduces a control unit to achieve intelligent and automated management of the ash cleaning operation. Intelligent linkage control is achieved by adjusting the opening degree of valve 23 and / or air valve 34 through the control unit.

[0087] As an feasible approach, load linkage control can be implemented based on actual operating conditions and detection data: when the unit is detected to be entering a low-load operation phase, the ash blowing device 3 is started in advance for pre-cleaning; if the unit is about to increase the load, the valve of the ash discharge device 2 is opened first to remove the loose dust and prevent the dust from being concentrated and raised, which would lead to excessive emissions.

[0088] As another feasible approach, dust concentration threshold control can be implemented based on actual operating conditions and detection data: if the dust concentration sensor at the dust collector inlet detects an abnormal upward trend, the control unit can automatically trigger the dust removal action; start the dust blowing device 3 to disturb the dust at the bottom of the flue, and at the same time, open the dust discharge device 2 to discharge the dust; stop the dust removal operation after the dust concentration returns to stability.

[0089] In addition, regular maintenance mechanisms and fault protection mechanisms can be implemented. The specific regular maintenance mechanism involves setting a timed dust removal mode and periodically executing a combined "blowing + exhaust" dust removal process; this is suitable for long-term stable operation and prevents dust accumulation that can cause blockages or corrosion. The fault protection mechanism involves the control unit automatically switching to a backup plan and sending an alarm signal to alert maintenance personnel when a dust removal device malfunctions (such as a stuck air valve or blocked pipeline). This is merely an example and not intended to be limiting.

[0090] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0091] Furthermore, in the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0092] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this utility model, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this utility model. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0093] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0094] Finally, it should be noted that the above embodiments are merely specific implementations of this utility model, used to illustrate the technical solution of this utility model, and not to limit it. The protection scope of this utility model is not limited thereto. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this utility model. These modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A flue, characterized in that, Extending along a first direction, it is used to connect the outlet of the air preheater and the inlet of the dust collector; the flue includes: a flue body and an ash discharge device and / or an ash blowing device connected to the flue body.

2. The flue according to claim 1, characterized in that, The ash discharge device includes: The ash hopper is connected at its top to the bottom of the flue body, and the ash hopper has a symmetrical structure along the central axis; the top end face dimension of the ash hopper is larger than the bottom end face dimension. The ash unloading device has its top end connected to the bottom of the ash hopper via a connecting pipe, and its bottom end connected to the ash hopper inside the dust collector via an ash conveying pipe. A valve is provided in the connecting pipeline.

3. The flue according to claim 2, characterized in that, The top end face dimension of the ash hopper is 80%-10% of the dimension of the flue body along the second direction; the downward tilt angle of the ash hopper is 65°-75°. The second direction is on the same horizontal plane as the first direction and is perpendicular to each other.

4. The flue according to claim 2, characterized in that, There are at least two ash hoppers, which are spaced apart along a first direction.

5. The flue according to claim 1, characterized in that, The dust removal device includes: The hood body is located at the bottom of the flue body; An air supply duct is located on the lower side of the flue body, with one end connected to an air source and the other end extending into the wind cap body; The air supply hole is located on the wind cap body and the airflow direction is opposite to that inside the flue body.

6. The flue according to claim 5, characterized in that, The wind cap body has multiple air supply holes, which are spaced apart.

7. The flue according to claim 6, characterized in that, There are multiple hood bodies, and the multiple hood bodies are spaced apart along the first direction and the second direction.

8. The flue according to claim 6, characterized in that, An air valve is installed on the air supply duct.

9. A gas purification system, characterized in that, Including the flue as described in any one of claims 1-8.

10. The system according to claim 9, characterized in that, It also includes a control unit, which is connected to the valve corresponding to the ash discharge device and the air valve corresponding to the ash blowing device.

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