A kiln tail gas chamber air root valve, cement kiln and method

Abstract

The application discloses a wind root valve for a kiln tail smoke chamber, a cement kiln and a method, relates to the technical field of valves, and solves the problem of wind resistance at the smoke chamber necking part in the prior art, has the beneficial effect of avoiding the existence of flow disturbance, and has the specific scheme as follows: a wind root valve for a kiln tail smoke chamber, a fixed part and a movable part are arranged above a smoke chamber outlet to form a ventilation channel, and the wind root valve inlet opening degree is matched with the opening degree of the top of the smoke chamber outlet; the lower part of the movable part is rotatably connected with the lower part of the fixed part to change the wind root valve outlet opening degree; when the wind root valve outlet opening degree is at the maximum opening degree, the minimum opening degree, and the outlet opening degree is between the maximum opening degree and the minimum opening degree, the working surface of the movable part is smoothly transitioned with the smoke chamber outlet side wall in space.

Description

Technical Field

[0001] This invention relates to the field of narrowing process of kiln tail smoke chamber in cement rotary kilns, and in particular to an air root valve for kiln tail smoke chamber, a cement kiln, and a method thereof. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In the existing rotary kiln process for cement clinker sintering, the narrowing at the kiln tail flue is usually the connecting channel between the rotary kiln and the decomposition furnace. The size of this connecting channel is related to the matching of the secondary and tertiary air volumes and has a certain correlation with the clinker sintering quality and output. In the existing technology, the flue is usually a fixed area and cannot be adjusted to increase or decrease according to the needs, making it difficult to adapt to changes in process conditions. Although existing technologies include regulating valves installed at the constriction of the smoke chamber, the temperature at the constriction is usually around 1150 degrees Celsius. The flue gas contains corrosive gases such as sulfur and chlorine, and the environment is characterized by high wind speed and high dust levels. Furthermore, the wind speed at the constriction is 35 to 25 meters per second, and the environment is harsh due to dust particles and the adhesion of molten viscous minerals. This results in a short service life for the regulating valves.

[0004] Existing technologies also propose solutions with fixed walls and movable walls. The movable wall can move linearly relative to the fixed wall to reduce the area at the constriction. However, in the initial state, the area of ​​the movable wall and the smoke chamber outlet are the same. During the adjustment process, the movable wall moves inward relative to the fixed wall, and a step is formed between the bottom of the movable wall and the top of the smoke chamber outlet (because the thickness of the movable wall reaches more than 10cm). In this way, the fluid flow path is not smooth, but in the form of a broken line. Moreover, the existence of the step causes eddy current problems. In addition to creating certain resistance to fluid flow, it also makes it easy for smoke and dust to deposit and form a crust at the step. Existing technologies also include adjustable smoke chamber constriction, with a movable plate installed on the top of the shell. When the movable plate is in the opening adjustment position, the air inlet is small and the air outlet is large. The movable plate intersects and opposes the fluid direction, and the area between the movable plate and the shell becomes a windward shielding area. The incoming air is compressed, violently bent, and forms a vortex to change direction, which causes great resistance and kinetic energy loss to ventilation. If the movable plate is in the maximum opening position, the resistance is reduced to the minimum, but the function of adjusting the ventilation area is lost. In the windward shielding area, the wind vortex speed is reduced, and smoke and dust are easy to adhere and form a crust. The fluid gradually expands from the air inlet to the air outlet. During this process, the central airflow moves inertially, and the surrounding gradually expanding channel does not constrain the airflow, which is scattered. The lifting force is reduced, and it is easy to form a material flow collapse channel. In summary, although existing technologies provide devices that allow for adjustment of the constriction area, they have wind-blocking areas that create resistance and affect the velocity of the fluid at the outlet and the smoothness of the flue gas. They also easily lead to fluid adhesion and the formation of a crust. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a wind root valve for the kiln tail smoke chamber, which has no windward obstruction area and ensures the flow rate of fluid.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: A root valve for a kiln tail flue includes a fixed part and a movable part placed between the flue outlet and the decomposition furnace. The movable part is movable relative to the fixed part. The fixed part and the movable part are positioned above the flue outlet to form a ventilation channel. The opening degree of the root valve inlet is adapted to the opening degree of the top of the flue outlet. The lower part of the movable part is rotatably connected to the lower part of the fixed part to change the opening degree of the root valve outlet. When the outlet opening degree of the root valve is at the maximum opening degree, the minimum opening degree, and between the maximum opening degree and the minimum opening degree, the working surface of the movable part smoothly transitions with the side wall of the flue outlet in space.

[0007] As described above, in a kiln tail flue gas chamber, the inlet opening of the flue gas chamber is greater than or equal to the outlet opening of the flue gas chamber. When the outlet opening of the flue gas chamber is at its maximum, the working surface of the movable part and the top of the inner surface of the corresponding flue gas chamber outlet side wall are located in the same vertical plane.

[0008] As described above, the movable part of the kiln tail smoke chamber is a fan-shaped structural component. The upper and lower sealing surfaces of the movable part are both arc-shaped, and the arc-shaped surfaces of the upper and lower sealing surfaces of the movable part are concentric with the axis at the connection between the movable part and the fixed part. The angle between the working surface of the active part and the vertical plane is between 15° and 25°.

[0009] As described above, in a kiln tail flue gas chamber air root valve, the upper sealing surface, lower sealing surface, and side sealing surface facing the fixed part of the movable part are all provided with flexible, heat-resistant sealing material, which is in contact with the movable part.

[0010] As described above, in a kiln tail flue gas valve, the heat-resistant sealing material is filled in a sealing box, the sealing box is detachable from the fixed part, and the sealing material protrudes from the sealing box to fully contact the moving part. The heat-resistant sealing material that contacts the upper and lower sealing surfaces of the moving part has an arc-shaped surface on both sides. The distance between the heat-resistant sealing material on the side of the moving part and the moving part is adjustable.

[0011] As described above, in a kiln tail flue gas chamber air root valve, the fixed part is provided with an opening, and an online cleaning mechanism is detachably installed at the opening. The online cleaning mechanism can blow air or flush water at the connection between the movable part and the fixed part. The online cleaning mechanism can be disassembled to lift the fixed part through the opening.

[0012] As described above, the air root valve for the kiln tail flue includes an online cleaning mechanism comprising a cover plate, which is detachably installed at the opening. The cover plate is provided with a guide tube, and a cleaning pipeline passes through the guide tube. The cleaning pipeline is movable and rotatable relative to the guide tube and can be connected to an air filling device or a water filling device.

[0013] As described above, in a kiln tail flue gas chamber air root valve, the outer surface of the movable part is connected to the drive mechanism, the fixed end of the drive mechanism is fixed, the drive mechanism is connected to the control unit, the fixed end of the drive mechanism is fixed to the support frame, and the movable end of the drive mechanism is connected to the upper side of the movable part.

[0014] As described above, a kiln tail flue gas valve has a distance measuring component installed on one side of the outer surface of the movable part. The distance measuring component is connected to the control unit. The distance measuring component measures the distance between itself and the movable part and sends the measurement to the control unit. The control unit obtains the outlet opening of the gas valve based on the distance between the distance measuring component and the movable part.

[0015] As described above, the fixed part includes two fixed walls located above the side wall of the smoke chamber outlet. The two fixed walls are opposite to each other and are both vertically arranged. The movable part is a movable wall, with two movable walls arranged opposite to each other between the two fixed walls. The lower part of the movable part is connected to the fixed part through a rotating shaft.

[0016] As described above, a bottom support member is provided at the bottom of the fixed part and the movable part, and a top connector is provided at the top of the fixed part and the movable part. The bottom support member is fixed to the top of the smoke chamber outlet, and the bottom support member and the top connector are respectively fixed to the fixed part. A first limiting platform is provided on the inner surface of the top connector, and the width of the first limiting platform is smaller than the width of the top connector; A second limiting platform is provided on the inner surface of the bottom support member. The second limiting platform supports the limiting plate, and the inner surface of the second limiting platform and the inner surface of the limiting plate are located on the same plane.

[0017] Secondly, the present invention also provides a cement kiln, including the aforementioned air root valve for the kiln tail flue.

[0018] Thirdly, the present invention also provides a method for adjusting the opening degree of the kiln tail smoke chamber outlet, comprising the following: Install the aforementioned air root valve for kiln tail smoke chamber at the smoke chamber outlet; Based on the changes in the firing temperature inside the kiln and / or the content of the selected gas in the flue and / or the outlet temperature of the decomposer and / or the increase in the outlet temperature of the decomposer and / or the pressure difference before and after the decomposer, the movable part is adjusted relative to the fixed part to regulate the opening of the air root valve outlet.

[0019] The beneficial effects of the present invention are as follows: The air root valve provided by this invention includes a fixed part and a movable part. The fixed part is fixed at the outlet of the kiln tail smoke chamber of a cement kiln. The bottom of the movable part is rotatably connected to the fixed part. The working surface of the movable part is inclined to the inside of the air root valve so that the inlet opening of the air root valve gradually becomes larger than the outlet opening. By continuously adjusting the position of the movable part, the outlet opening of the air root valve can be effectively changed, thereby realizing the regulation of the ventilation air volume in the rotary kiln. Through the rotation of the movable part relative to the fixed part, the smoothness of the fluid is effectively improved, so that the ventilation air volume regulation state is a process of gradual reduction of ventilation area, no windward obstruction area, increased ventilation outlet speed, low resistance, and low kinetic energy loss. The wind speed at the part of the movable part that comes into contact with the smoke and dust is high, making it less likely to deposit and form a crust. Through the cooperation of the movable part and the fixed part in this invention, after the movable part is tilted inward, the fluid gradually shrinks from the air inlet to the air outlet. During this process, the air constraint of the shrinking channel gradually increases, the force is concentrated, the outlet lifting force increases, and it is not easy to form a material flow collapse channel. Regardless of whether the outlet opening of the air valve is at its maximum or minimum opening, or between the maximum and minimum opening, the working surface of the moving part and the side wall of the smoke chamber outlet are smoothly transitioned in space without any protruding structure. That is, no step is generated between the bottom side of the moving part and the bottom support, and there is no turbulence problem caused by the presence of steps in the existing technology. Overall, it can be adapted to the requirements of cement rotary kilns for good control of excess ventilation and decomposition furnaces for good bubbling effect. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a front view of a kiln tail flue gas valve according to one or more embodiments of the present invention.

[0022] Figure 2 This is an enlarged view of the movable part of a kiln tail flue gas chamber air root valve when it is at its maximum outlet opening, according to one or more embodiments of the present invention.

[0023] Figure 3 This is an enlarged view of the movable part of a kiln tail flue gas chamber air root valve when it is at its minimum outlet opening, according to one or more embodiments of the present invention.

[0024] Figure 4 This is a schematic diagram of the cooperation between the movable part and the column in a kiln tail smoke chamber air root valve according to one or more embodiments of the present invention.

[0025] Figure 5 This is a simplified diagram of the movable part of a kiln tail flue gas valve in one or more embodiments of the present invention at the maximum outlet opening position.

[0026] Figure 6 This is a simplified diagram of the movable part of a kiln tail flue gas valve according to one or more embodiments of the present invention at the minimum outlet opening.

[0027] Figure 7 This is a top view of a kiln tail flue gas valve according to one or more embodiments of the present invention.

[0028] Figure 8 This is a side view of a kiln tail flue gas valve according to one or more embodiments of the present invention.

[0029] Figure 9 This is a front view of the top side seal of a kiln tail flue gas chamber according to one or more embodiments of the present invention.

[0030] Figure 10 This is a side view of the top side seal of a kiln tail flue gas chamber according to one or more embodiments of the present invention.

[0031] Figure 11 This is a front view of the bottom sealing element of the air root valve for the kiln tail flue according to one or more embodiments of the present invention.

[0032] Figure 12 This is a side view of the bottom sealing element of the air root valve for the kiln tail flue according to one or more embodiments of the present invention.

[0033] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0034] The components are: 1. Top connector, 2. First limiting platform, 3. Top side seal, 4. Movable part, 5. Drive mechanism, 6. Fixed part, 7. Bottom side seal, 8. Bottom support, 9. Support frame, 10. Reinforcing member, 11. Rotating shaft, 12. Horizontal bending frame, 13. End plate, 14. Vertical frame, 15. Second limiting platform, 16. Bottom side sealing box, 17. Online cleaning mechanism, 18. Column, 19. Distance measuring component, 20. Cover plate, 21. Top plate, 22. First side plate, 23. Bottom plate, 24. Second side plate, 25. Long strip hole, 26. Third temperature-resistant sealing material, 27. First temperature-resistant sealing material, 28. First reinforcing plate, 29. Diagonal reinforcing rod, 30. Limiting plate. Detailed Implementation

[0035] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be noted that the inner surface of the moving part that changes the inlet and outlet opening of the air root valve is referred to as the working surface of the moving part, and the outer surface of the moving part is relative to the working surface of the moving part. The inlet opening of the air root valve refers to the opening degree of the air root valve on the side closer to the smoke chamber outlet, while the outlet opening of the air root valve refers to the opening degree of the air root valve on the side closer to the decomposition furnace.

[0037] As described in the background section, existing air root valves suffer from problems such as obstructed windward area, easy crusting, and reduced fluid flow velocity. To address these technical issues, this invention proposes an air root valve for kiln tail flue.

[0038] Example 1 In a typical embodiment of the present invention, reference is made to Figure 1 , Figure 7 and Figure 8 As shown, a root air valve for a kiln tail flue, wherein the inlet opening of the root air valve is greater than or equal to the opening at the top of the flue outlet, includes: The fixing part 6 has a set height and is located on opposite sides of the smoke chamber outlet; The movable part 4 and the fixed part 6 are positioned above the smoke chamber outlet to form a ventilation channel. The opening of the air root valve inlet is adapted to the opening of the top of the smoke chamber outlet. The lower part of the movable part 4 is rotatably connected to the lower part of the fixed part 6 to change the opening of the air root valve outlet, so that the air root valve outlet opening is less than or equal to the air root valve inlet opening to ensure the smooth flow of flue gas through the ventilation channel and prevent material collapse. The movable part 4 is located on the open side of the fixed part 6 or on the other opposite sides of the smoke chamber outlet. The lower part of the movable part 4 and the fixed part 6 are rotatably connected. When the movable part 4 moves relative to the fixed part 6 to the maximum outlet opening, the working surface of the movable part 4 is aligned with the side wall of the smoke chamber outlet at the kiln tail. On the same vertical plane, when the outlet opening of the air root valve is at its maximum opening, minimum opening, and between the maximum and minimum opening, the working surface of the moving part and the side wall of the smoke chamber outlet transition smoothly in space without any protruding structures, ensuring smooth flue gas flow. When the moving part 4 moves relative to the fixed part 6 to the minimum outlet opening, the working surface of the moving part 4 tilts towards the outlet of the cement kiln tail smoke chamber, so that the opening of the air root valve inlet (the side closer to the outlet of the cement kiln tail smoke chamber) is greater than the opening of the outlet (the side closer to the decomposition furnace). Regardless of whether the inlet opening is greater than or equal to the outlet opening, the smooth flow of flue gas can be guaranteed, avoiding material collapse problems.

[0039] The airflow valve provided in this embodiment has a reasonable structural design. The inner surface of the movable part 4 has no inward protruding structure, so there is no windward obstruction area (step) at the bottom of the movable part 4 during the rotation of the movable part 4 relative to the fixed part 6. This not only avoids the generation of eddies but also ensures smooth fluid flow. After rotation, the inner surface of the movable part 4 is inclined upward relative to the horizontal plane, so that the inlet opening of the airflow valve is greater than the outlet opening. This results in a gradual reduction of the ventilation area without windward obstruction, increased ventilation outlet speed, low resistance, and low kinetic energy loss. As the fluid gradually shrinks from the inlet to the outlet, the wind constraint of the shrinking channel gradually increases, the force is concentrated, and the outlet lifting force increases, making it less likely to form a material flow collapse channel. Moreover, the wind speed at the part of the movable part 4 that comes into contact with smoke and dust is high, making it less likely to deposit or form a crust, which helps to extend the maintenance cycle of the airflow valve.

[0040] It should be explained that the top of the fixing part 6 and the top of the corresponding smoke chamber outlet side wall are located on the same vertical plane. Due to installation error, the fixing part 6 may extend beyond or retract into the top of the corresponding smoke chamber outlet side wall. This error is not too large and its impact on the fluid is negligible. Therefore, the installation error is within the allowable range.

[0041] In this embodiment, considering that the movable part 4 needs to rotate relative to the fixed part 6, and that the top and bottom need to be sealed to prevent leakage of ambient air and high-temperature flue gas, the upper and lower sealing surfaces of the movable part 4 are arc-shaped. The arc-shaped structures of the upper and lower sealing surfaces of the movable part 4 are concentric with the axis at the connection between the movable part 4 and the fixed part 6. If it were a planar structure, the top and bottom would not be sealed properly during the rotation of the movable part 4, resulting in air leakage.

[0042] Considering that the air root valve also needs to be connected to the decomposition furnace, a top connector 1 is also provided on the top of the air root valve. The top connector 1 can be connected to the decomposition furnace above the smoke chamber outlet. The top connector 1 is installed on the top of the movable part 4 and the fixed part 6. The movable part 4 is in sealed contact with the bottom support 8, the top connector 1, and the fixed part 6 respectively.

[0043] It is easy to understand that the top connector 1 is specifically a frame-shaped top connecting plate (equivalent to a connecting flange). In some examples, the top connector 1 is simply set on the top of the movable part 4. The top connector 1 and the top of the fixed part 6 are set on the same plane. The top connector 1 is provided with multiple openings for fasteners such as bolts to pass through the top connector 1 and connect to the decomposition furnace. The size of the top connector 1 is the same as the size of the bottom support 8. The inner wall of the top connector 1 is provided with a downward first limiting platform 2 to limit the top side seal 3.

[0044] Regarding the bottom support 8, its shape is consistent with the top of the outlet of the cement kiln tail smoke chamber, and its internal dimensions are also the same. This ensures that the inner surface of the top connector 1 will not have any protrusions or steps that could easily cause turbulence. The bottom support 8 can be a frame structure. The top connector 1 has multiple openings. Fasteners such as bolts pass through the bottom support 8 and connect to the top of the outlet of the cement kiln tail smoke chamber. The fixing part 6 is located on the upper surface of the bottom support 8 and is fixedly connected to the bottom support 8.

[0045] Additionally, an upward-facing second limiting platform 15 is provided on the inner wall of the bottom support member 8 to limit the bottom sealing member 7. Furthermore, an upward-facing limiting plate 30 is provided along the inner wall of the second limiting platform 15 on the inner wall of the bottom support member 8. When the movable part 4 moves to the minimum outlet opening, the top of the limiting plate 30 can contact the working surface of the movable part 4. The limiting plate contacts the bottom side of the movable part 4 to prevent flue gas from flowing between them. When the movable part 4 moves to the maximum outlet opening, the side of the bottom protrusion structure of the movable part is positioned above the limiting plate 30, with a gap of less than 2mm. When the movable part 4 moves between the minimum and maximum outlet opening, there is a certain gap between the limiting plate 30 and the movable part 4. However, since this gap is less than or equal to 2mm and there is no inward protrusion structure, its impact on the fluid is negligible. The bottom of the fixed part 6 is provided with a support ear. Multiple triangular reinforcing ribs are provided between the support ear and the upper surface of the bottom support member 8 to ensure reliable support for the fixed part 6. The support ear is also provided with multiple openings to facilitate the connection of fasteners to the fixed part 6, the bottom support member 8 and the top of the outlet of the cement kiln tail smoke chamber.

[0046] In this embodiment, the fixed part 6 includes two opposing fixed walls, and the movable part 4 is a movable wall. There are two movable walls, and the two movable walls are also opposing each other.

[0047] In other examples, the fixed part 6 forms a U-shaped structure with an opening on one side, and the movable part 4 is placed at the opening of the fixed part. In this way, as the movable part 4 rotates inward relative to the fixed part 6, a gradually narrowing ventilation channel can be formed, which is also conducive to the gradual increase of fluid flow rate.

[0048] In other examples, the fixed part 6 is determined according to the structural form of the outlet of the cement kiln tail smoke chamber. If the outlet of the cement kiln tail smoke chamber has a hexagonal structure, the fixed part 6 includes three fixed walls spaced apart, and the movable part 4 also includes three movable walls spaced apart.

[0049] Considering that the internal flow of the air root valve is high-temperature flue gas, in order to isolate the internal high-temperature flue gas from the external environment, the upper sealing surface, lower sealing surface, and side sealing surface facing the fixed part 6 of the movable part 4 are all provided with flexible heat-resistant sealing material. The flexible heat-resistant sealing material is in contact with the movable part 4 and can be compressed. During the rotation of the movable part 4 relative to the fixed part 6, the sealing performance of each surface of the movable part is guaranteed. By providing heat-resistant sealing material on the periphery of the movable part, the temperature on the outside of the air root valve is kept below 70°C, effectively isolating high temperature. Moreover, the width of the heat-resistant sealing material is 3 / 4-1 of the minimum thickness of the non-bottom arc part of the movable part, thus ensuring the sealing effect of the upper sealing surface, lower sealing surface, and side sealing surface of the movable part.

[0050] Specifically, a top-side seal 3 is provided between the top connector 1 and the movable part 4. The top-side seal 3 includes a top-side sealing box, which is detachably connected to the top connector 1. Thus, when the first heat-resistant sealing material 27 reaches the end of its service life and needs to be replaced, due to the limited space, manual assistance tools can be used to remove the top-side sealing box relative to the top connector 1 under external force, and the first heat-resistant sealing material 27 inside the top-side sealing box can be replaced. The first heat-resistant sealing material 27 is provided inside the top-side sealing box and on its inner side. The top-side sealing box has a set width to ensure that the upper sealing surface of the movable part 4 is in full contact with the first heat-resistant sealing material 27 during the rotation of the movable part 4. The first heat-resistant sealing material 27 is flush with or protrudes from the top-side sealing box to contact the movable part 4, preventing the internal flue gas from flowing out from between the top-side sealing box and the movable part 4.

[0051] It is easy to understand that the length of the top sealing box is the same as the length of the upper side of the movable part corresponding to the top connector 1, for reference. Figure 9 As shown, the top-side sealing box includes a top plate 21, which contacts the top connector 1. The top plate 21 supports three first side plates 22. The inner first side plate 22 is lower in height, while the other two first side plates 22 are at the same height. A first heat-resistant sealing material 27 is inserted between two adjacent first side plates 22. A first reinforcing plate 28 is provided between two adjacent first side plates 22. The top plate 21 extends beyond the first side plates 22 on the side. The top plate 21 is provided with multiple elongated holes, which are used to connect the top-side sealing box to the top connector 1. The installation position of the top-side sealing box can be adjusted by the elongated holes. A first heat-resistant sealing material is also provided between the outer side of the first side plate 22 on the other side and the first limiting platform 2 of the top connector 1 to further prevent leakage of ambient air and high-temperature flue gas.

[0052] In some examples, refer to Figure 10 As shown, two adjacent first side plates 22 are connected by multiple first reinforcing plates 28, the outermost first side plate 22 is welded to the top plate 21, and the space between two adjacent first side plates 22 is filled with a first heat-resistant sealing material 27.

[0053] It should be noted that the outer surface of the first heat-resistant sealing material 27 away from the top sealing box is an arc-shaped surface or a flat surface. When it is an arc-shaped surface, the center of the arc-shaped surface is the connection between the movable part 4 and the fixed part 6. That is to say, the outer surface of the first heat-resistant sealing material is concentrically set with the movable part. In this way, the arc-shaped surface of the first heat-resistant sealing material can always effectively fit with the upper sealing surface of the movable part during the movement of the movable part. Considering the installation of the movable part 4, a column 18 is provided on the side of the fixed part, and an oblique reinforcing rod 29 is provided between the bottom support 8 and the column to enhance the support strength of the column 18. The two columns 18 are arranged opposite to each other and the columns 18 are welded to the fixed part 6. The columns 18 can be H-shaped steel to ensure structural strength. A side seal is provided on the inside of the column 18. The side seal includes a side sealing box. The side sealing box can be pulled out relative to the column. A second heat-resistant sealing material is provided inside the side sealing box. The second heat-resistant sealing material can contact the side wall of the movable part. The adjusting part passes through the column and abuts against or is detachably connected to the side sealing box. The side sealing box specifically includes a box body, a second heat-resistant sealing material is installed inside the box body, the box body is vertically installed, the second heat-resistant sealing material extends beyond the box body, and an adjusting component such as an adjusting bolt passes through the column 18 and abuts or connects with the vertical plate of the box body. Multiple adjusting bolts can be installed in the vertical height. By adjusting the bolts, the second heat-resistant sealing material can be made to have close contact with the side wall of the movable part 4.

[0054] In this embodiment, the movable part 4 is cast using a heat-resistant and heat-insulating material. Multiple reinforcing members 10 are provided inside the movable part 4. Specifically, the reinforcing members 10 can be Y-shaped structural members. The Y-shaped structural members ensure the structural strength of the movable part. The heat-resistant and heat-insulating material is a cast-in-place heat-resistant and heat-insulating material in the prior art, thereby ensuring the high temperature resistance and heat insulation performance of the movable part. In other examples, the movable part 4 can be manufactured and processed using other structural members.

[0055] Moreover, the movable part 4 has a set thickness to ensure that the movable part 4 enters the top of the outlet of the cement kiln tail smoke chamber during rotation. The middle and bottom sides of the outer side of the movable part 4 are hollowed out, which helps to reduce the overall weight, facilitates casting and molding, and facilitates connection with the drive mechanism 5. In this embodiment, the movable part 4 is a fan-shaped structural component. The lower side of the movable part 4 is connected to the columns on both sides through a rotating shaft 11. The diameter of the middle part of the rotating shaft 11 is larger than the diameter of both ends to prevent axial movement. After the rotating shaft 11 is installed, an end plate 13 is provided at the end. The end plate 13 is connected to the column 18. A protrusion is provided at the bottom of the movable part 4. The protrusion is an arc-shaped protrusion. Small limiting protrusions are provided on both sides of the rotating shaft 11 to ensure the smooth rotation of the movable part 4. When the movable part 4 is in the first extreme position, the inner surface of the movable part 4 is on the same vertical plane as the side wall of the outlet of the cement kiln tail smoke chamber. The bottom support 8 is provided with a bottom side seal 7. The bottom side seal includes a bottom side sealing box that is detachably connected to the bottom support 8. A third heat-resistant sealing material is provided inside the bottom side sealing box 16. The third heat-resistant sealing material is in contact with the lower sealing surface of the movable part. The bottom side of the movable part 4 is rotatably connected to the bottom side of the fixed part. In other examples, other rotary structures can be used for lightweight air root valves.

[0056] For details, please refer to Figure 11 As shown, the bottom sealing box 16 includes a bottom plate 23, which supports three second side plates 24. The second side plates 24 are vertically connected to the bottom plate 23. From the outside to the inside, the height of the three second side plates 24 decreases sequentially to match the shape of the protrusion at the bottom of the movable part 4. The innermost second side plate 24 avoids interference with the movable part 4 during rotation. The bottom plate 23 extends beyond the outermost second side plate 24. The portion of the bottom plate 23 extending beyond the second side plate 24 has an elongated hole 25 to facilitate connection with the bottom support member 8. A third heat-resistant sealing material 26 is provided between the bottom sealing box 16 and the second limiting platform 15 of the bottom support member 8. The second side plates 24 are also filled with the third heat-resistant sealing material. The height of the third heat-resistant sealing material 26 is lower than that of the outermost second side plate 24 to ensure sufficient contact between the third heat-resistant sealing material 26 and the movable part 4.

[0057] In some examples, refer to Figure 12 As shown, two adjacent second side plates 24 are connected by a second reinforcing plate. The bottom plate 23 is placed outside the outermost and higher second side plate 24. The bottom plate 23 is welded to the outermost second side plate 24. Multiple reinforcing plates are provided between the bottom plate 23 and the outermost second side plate 24.

[0058] It is easy to understand that the first, second, and third heat-resistant sealing materials all use existing fire-resistant and high-temperature resistant materials, such as aluminum silicate refractory cotton or other fire-resistant and high-temperature resistant materials.

[0059] For details, please refer to Figure 5 As shown, when the inner surface of the moving part 4 is vertical, the outlet opening D of the air root valve reaches its maximum value D0, the outlet opening is at its maximum, and the inlet opening D... I D0 is the first extreme position; see reference. Figure 6 As shown, when the movable part 4 rotates into the inner cavity, causing the horizontal distance of the inner side of the upper arc segment of the movable part to decrease by a first distance Dc, the outlet opening D of the air root valve reaches the designed minimum value (D0-2*D). C ), Inlet opening degree D I ≥D0 (Because the bottom of the movable part has an arc-shaped protrusion, when the movable part is not in the first extreme position, the outlet opening D is always less than the outlet opening D0 in the first extreme position, so the inlet opening is greater than or equal to the maximum value of the outlet opening), this is the second extreme position; during the movement of the movable part 4 from the first extreme position to the second extreme position, the outlet opening D gradually decreases, and the inlet opening D I The change in the outlet opening D of the air valve increases, thereby adjusting the outlet opening of the air valve.

[0060] It should be noted that the reference Figure 4As shown, the angle of the movable part 4 is typically 15°-25° to ensure the minimum opening of the air valve. The height of the movable part 4 is less than the height of the fixed part 6. The designed outlet opening of the movable part 4 is the horizontal distance from the top edge of the inner surface of the movable part 4 to the projection of the inner vertical edge of the column 18. Because the movable part 4 rotates relative to the column, the angle of the movable part... The angle between the working surface of the moving part and the outer surface is greater than or equal to the rotational stroke of the moving part. In this embodiment, the angle of the movable part is limited for design convenience. Equal to the rotation angle travel of the moving part When the length of the working surface of the movable part (from the limiting protrusion on the inner surface of the movable part 4 to the top edge on the inner surface of the movable part 4) is L, the movable part is designed to adjust the opening D, and the inner surface of the column and the working surface of the movable part form a right triangle. The sine value is the design adjustment opening D of the movable part / the length L of the working surface of the movable part. Therefore, the angle of the movable part is determined based on the sine value of the design adjustment opening D and the length of the working surface of the movable part. .

[0061] For easy adjustment, please refer to Figure 2 As shown, when the air valve is at its maximum opening, the inner side of the movable part 4 is in a vertical position, and the outer side of the movable part 4 protrudes beyond the fixed part 6; in some examples, the outer surface of the movable part may not protrude beyond the fixed part at this time; see reference. Figure 3 As shown, when the air valve opening is at its minimum, the outer surface of the movable part 4 is in a vertical plane, and the angle between the inner surface of the movable part 4 and the vertical plane, i.e., the rotation angle of the movable part, is between 15° and 25°. Within this range, the adjustment requirements of the air valve outlet opening are met. This is based on the reasonable design of the movable part to adjust the opening. Within this range, the air valve outlet opening can be effectively adjusted according to specific needs. In some examples, the angle between the inner surface of the movable part 4 and the vertical plane, i.e., the rotation angle of the movable part, is 21°. Of course, in other examples, the outer surface may not be in a vertical plane.

[0062] In this embodiment, limiting members are respectively provided on both sides of the outer side of the movable part 4. The limiting members can be placed on the upper, middle or bottom of the movable part. One side of the limiting member is fixed to the movable part, and the other side extends beyond the movable part. When the opening of the air root valve is at its minimum, the limiting member can contact the fixed part to limit it. The limiting member is specifically a limiting block, and the limiting block has a set height and length.

[0063] To enable the rotation of the movable part 4 relative to the fixed part 6, the outer side of the movable part 4 is hinged to the drive mechanism 5. The fixed end of the drive mechanism 5 is fixed. The drive mechanism 5 is connected to the control unit and fixed to the support frame 9. The bottom side of the support frame 9 is fixed (fixed to a location where it can be installed on site). The support frame 9 specifically includes a horizontal bending frame 12 and a vertical frame 14. The bottom of the vertical frame 14 can be installed with bolts. The vertical frame 14 connects two horizontal bending frames 12. The two sides of the support frame 9, i.e., the horizontal bending frames, are connected to the side of the uprights 18 on the side of the fixed part. The connection point of the support frame 9 with the fixed part is higher than the connection point of the movable part 4 and the fixed part 6, i.e., the pivot 11, to ensure the driving length and control torque of the drive mechanism 5. The fixed end of the drive mechanism 5 is fixed to the support frame 9, and the movable end of the drive mechanism 5 is connected to the upper side of the movable part 4. Under normal conditions, the drive mechanism is inclined upward relative to the horizontal bending frame.

[0064] The control unit is specifically a PLC controller or other type of controller. The controller simultaneously controls the drive mechanisms on both sides to ensure simultaneous control of the moving parts.

[0065] It is easy to understand that, in order to achieve precise control without manual monitoring, a ranging component 19 is set at the support frame 9. The ranging component 19 can be an existing laser ranging sensor or an infrared ranging sensor. The ranging component 19 is set facing the outer surface of the movable part 4. The ranging component 19 is connected to the control unit. The ranging component is set at the support frame 9 and is protected by a cover. The cover is open to ensure that the ranging component can emit laser or infrared rays toward the movable part. The ranging component is used to measure the distance between itself and the movable part and send it to the control unit. The control unit obtains the outlet opening of the wind root valve based on the distance between the ranging component and the movable part.

[0066] Specifically, the control unit has an operable display screen through which the target outlet opening of the wind root valve can be input. The control unit also stores the horizontal measurement distances between the two ranging components 19 and the outer surfaces of the two movable parts at their minimum opening. The control unit subtracts the input real-time horizontal measurement distances between the two ranging components 19 and the outer surfaces of the two movable parts from these distances to obtain the distances that the outer surfaces of the two movable parts 4 move across the horizontal measurement sections of the two ranging components 19. Based on the calculated distances and the determined angles, sides, and other relationships, the control unit can calculate the real-time opening of the wind root valve and compare it with the set target outlet opening. The control unit then outputs the control to simultaneously activate the drive mechanisms on both sides until the ranging components detect that the real-time opening of the wind root valve meets the requirements.

[0067] It should be explained that the drive mechanism 5 is specifically an electrically controlled hydraulic drive cylinder or an electrically controlled crank connecting rod mechanism. The control unit is connected to the remote DCS control system (distributed control system). In the existing technology, the adjustment needs to be made manually on-site. However, the on-site environment is in a high temperature and high dust environment, which poses a great risk to the operation. By setting up remote DCS control, remote adjustment can be realized, reducing the frequency of human-machine contact and improving the inherent safety management.

[0068] Considering the large weight of the fixed part 6 and the movable part 4, which require hoisting and installation, and the need to clean the crust between the movable part 4 and the fixed part 6 after the set time of use of the air root valve, the movable part 4 and the fixed part 6 are provided with openings. Specifically, two openings are provided, one for cleaning the gap between the movable part 4 and the fixed part 6 in one location. This facilitates online cleaning of the crust between the movable part 4 and the fixed part 6. The online cleaning mechanism 17 is detachably installed at the opening. The online cleaning mechanism can blow air or flush water at the connection between the movable part and the fixed part. The online cleaning mechanism can be disassembled to hoist the fixed part through the opening.

[0069] Specifically, the online cleaning mechanism 17 includes a cover plate 20, which is detachably installed at an opening near the side of the movable part 4 or the fixed part 6. The opening can be connected by bolts. The movable part 4 and the fixed part 6 each have two openings. A guide tube is provided on the cover plate 20, passing through and fixed to it. A cleaning pipe passes through the guide tube and is movable and rotatable relative to the guide tube. The outer diameter of the cleaning pipe is smaller than the inner diameter of the guide tube, and the cleaning pipe has a limiting protrusion to prevent it from being pulled out of the guide tube. The pipeline is L-shaped and can be connected to an air filling device or a water filling device. In this embodiment, an air filling device such as an air compressor can be selected to fill the space between the moving part and the fixed part with high-pressure gas through the cleaning pipeline. The cleaning pipeline can be moved or rotated during the cleaning process to ensure the working area and cleaning effect. In this way, it is not necessary to disassemble the air root valve, cover the bottom of the decomposition furnace, and then have the staff enter the air root valve for cleaning, as in the prior art. This embodiment sets up an online cleaning mechanism to clean the scale quickly and greatly improve the safety of the operation.

[0070] In other examples, the online cleaning mechanism may also employ other structures.

[0071] In summary, the air root valve provided in this embodiment, with the bottom side of the movable part as the center of tilting rotation, the process of the two movable walls tilting inward synchronously from a vertical state is the process of reducing the ventilation area of ​​the air root valve, and the process of returning to a vertical state from the inward tilting state is the process of increasing the ventilation area of ​​the air root valve. The tilting amplitude determines the valve opening, and the horizontal angle between the flue gas contact surface of the movable wall and the valve is 90° to 65° to avoid excessive ventilation resistance of the air root valve. It can realize the adjustment of the air root valve with a large inlet and a small outlet, with no wind-blocking area. The setting of the control unit provides the execution end foundation for realizing unmanned, intelligent expert control of the kiln system. Existing technologies often result in kiln ventilation imbalances, leading to large fluctuations in CO (carbon monoxide) concentration, increased initial NOx (nitrogen oxides) generation, and high ammonia consumption. However, using the air root valve in this embodiment stabilizes the air-coal ratio and CO concentration, creating conditions for precise denitrification, saving ammonia consumption, and reducing secondary pollution from ammonia escape. Furthermore, existing air root valves suffer from reduced effective area due to crusting and material buildup, restricting kiln ventilation and forcing reduced production. The air root valve provided in this embodiment allows for online expansion of the opening to compensate for crusting, maintaining full-load operation; or it can be adjusted according to the decomposition furnace load to prevent material collapse. Under the same heat consumption, it ensures clinker hourly output, resulting in stable kiln calcination and guaranteed clinker quality.

[0072] In addition, if the movable part 4 is corroded, the drive mechanism 5 can be disassembled, and the movable part 4 can be rotated outward to a near-flat state. The movable part 4 can be repaired or remade without risk. The operation is very safe and simple. This maintenance method replaces the original high-risk and high-cost maintenance method of repairing and replacing the movable wall at the constriction of the smoke chamber with a low-risk and low-cost method. It does not require entering the decomposition furnace to clean the scale, nor does it require building scaffolds above the working surface for construction personnel to enter the constriction of the smoke chamber to repair the movable part 4. This effectively prevents the problem of scale falling off from the high place of the decomposition furnace and injuring people, and improves the safety of operation.

[0073] Example 2 This embodiment provides a cement kiln, including the air root valve for the kiln tail smoke chamber described in Embodiment 1. The cement kiln is a continuous thermal equipment used for high-temperature heat treatment of solid materials. By setting the air root valve at the kiln tail smoke chamber of the rotary kiln, the opening of the smoke chamber outlet can be easily adjusted. In conjunction with the opening of the tertiary air damper of the cement kiln, the air volume entering the kiln can be increased, and the calcination temperature can be improved.

[0074] Example 3 A method for adjusting the opening of the kiln tail smoke chamber outlet, using a kiln tail smoke chamber air root valve as described in Example 1, includes the following: Install bottom support component 8 at the top of the outlet of the cement kiln tail smoke chamber; The fixing part 6 is installed on the upper surface of the bottom support 8. The fixing part 6 forms a U-shaped structure with one side open, or the fixing part 6 is located on opposite sides of the smoke chamber outlet. A column 18 is provided on the side of the fixing part 6, and a side sealing element is provided inside the column 18. The movable part 4 is hoisted to the open side of the fixed part 6 or to the other two opposite sides of the smoke chamber outlet. The movable part 4 and the side of the fixed part 6 are rotatably connected. A top connector 1 is provided on the top of the movable part 4. The top connector 1 is welded to the top of the fixed part 6 and then connected by fasteners. A top-side seal 3 is installed on the top side of the movable part 4, and a bottom-side seal 7 is installed on the bottom side of the movable part; Install the drive mechanism 5 and the control unit; and connect the drive mechanism 5 and the control unit.

[0075] After installation, when feeding materials into the cement kiln, the air outlet area of ​​the device should be set to be the same as the area before the modification. This operation makes it easier to achieve the system balance state before the modification. The movable part 4 is rotated relative to the fixed part 6, so that the movable part 4 rotates toward the smoke chamber outlet. The inner surface of the movable part 4 is inclined upward relative to the horizontal plane, so that the inlet opening of the air root valve is greater than the outlet opening. The movable part continues to rotate toward the smoke chamber, so that the outlet opening of the air root valve continues to decrease. The movable part 4 is rotated in the opposite direction, so that the outlet opening of the air root valve increases.

[0076] In addition, based on temperature sensors or clinker testing, if the staff determines that the kiln firing temperature changes more than the set value, the clinker quality inspection results show high free calcium, or the clinker internal cross-section is loose and porous, it is possible that the raw meal powder is short-circuiting into the kiln. In this case, the staff will reduce the opening of the air root valve outlet (to match the opening of the tertiary air damper), increase the air velocity at the air root valve outlet, enhance the effect of flue gas spraying into the decomposition furnace, and reduce the amount of raw meal powder short-circuiting into the kiln. If necessary, the staff will increase the speed of the high-temperature fan to ensure the total air volume.

[0077] When phenomena such as low firing temperature in the kiln, increased firing temperature growth with increased head coal amount being lower than the set value, and CO content in the smoke chamber (or other selected gases) being higher than the set value occur, it is determined that the ventilation in the kiln is insufficient. At this time, the air outlet area of ​​the air root valve can be increased, the opening of the tertiary air damper can be reduced, the air volume entering the kiln can be increased, and the calcination temperature can be increased. If necessary, the speed of the high-temperature fan can be increased to ensure the total air volume.

[0078] If phenomena such as low outlet temperature of the decomposition furnace, temperature increase of the decomposition furnace below the set value after increasing the amount of tail coal, and temperature of the five-stage cyclone preheater higher than the temperature of the decomposition furnace occur, it is judged that the combustion rate of the pulverized coal injected into the decomposition furnace is insufficient. At this time, the air outlet area of ​​the air root valve can be reduced, the opening of the tertiary air damper can be increased, the tertiary air volume entering the furnace can be increased, and the combustion rate and decomposition rate of pulverized coal in the decomposition furnace can be improved. If necessary, the speed of the high-temperature fan can be increased to ensure the total air volume.

[0079] When clinker quality and output are stable, but the pressure difference between the front and back of the decomposition furnace is greater than the set value, the air outlet area of ​​the air root valve is increased and the opening of the tertiary air damper is increased to reduce system resistance and thus reduce the speed and energy consumption of the high-temperature fan.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A kiln tail flue gas valve, comprising a fixed part and a movable part positioned between the flue gas outlet and the decomposition furnace, wherein the movable part is movable relative to the fixed part, characterized in that, The fixed part and the movable part are positioned above the smoke chamber outlet to form a ventilation channel. The opening of the air root valve inlet is adapted to the opening of the top of the smoke chamber outlet. The lower part of the movable part is rotatably connected to the lower part of the fixed part to change the opening of the air root valve outlet. When the outlet opening of the air root valve is at the maximum opening, the minimum opening, and between the maximum opening and the minimum opening, the working surface of the movable part and the side wall of the smoke chamber outlet are smoothly transitioned in space without any protruding structures. The inlet opening of the air root valve is greater than or equal to the outlet opening of the air root valve. When the outlet opening of the air root valve is at its maximum, the working surface of the movable part and the top of the inner surface of the corresponding smoke chamber outlet side wall are located on the same vertical plane, so that the ventilation air volume adjustment state is a process of gradual reduction of ventilation area and no windward obstruction area. The movable part is a fan-shaped structural component. Both the upper and lower sealing surfaces of the movable part are arc-shaped, and the arc-shaped surfaces of the upper and lower sealing surfaces of the movable part are concentric with the axis at the connection between the movable part and the fixed part. The upper sealing surface, lower sealing surface, and side sealing surface facing the fixed part of the movable part are all provided with flexible, heat-resistant sealing material, which is in contact with the movable part. The heat-resistant sealing material is filled in the sealing box, which is detachable from the fixed part, and the sealing material protrudes from the sealing box to fully contact the moving part. The heat-resistant sealing material that contacts the upper and lower sealing surfaces of the moving part has an arc-shaped surface on both sides. The distance between the heat-resistant sealing material on the side of the moving part and the moving part is adjustable.

2. The air root valve for the kiln tail flue according to claim 1, characterized in that, The angle between the working surface of the movable part and the vertical plane is between 15° and 25°.

3. The air root valve for the kiln tail flue according to claim 1, characterized in that, The fixed part is provided with an opening, and the online cleaning mechanism can be detachably installed at the opening. The online cleaning mechanism can blow air or spray water at the connection between the movable part and the fixed part. The online cleaning mechanism can be disassembled to lift the fixed part through the opening.

4. The air root valve for the kiln tail flue according to claim 3, characterized in that, The online cleaning mechanism includes a cover plate, which is detachably installed at the opening. The cover plate is provided with a guide tube, through which the cleaning pipeline passes. The cleaning pipeline is movable and rotatable relative to the guide tube, and can be connected to an air inflation device or a water inflation device.

5. The air root valve for the kiln tail flue according to claim 1, characterized in that, The outer surface of the movable part is connected to the drive mechanism. The fixed end of the drive mechanism is fixed. The drive mechanism is connected to the control unit. The fixed end of the drive mechanism is fixed to the support frame. The movable end of the drive mechanism is connected to the upper side of the movable part.

6. The air root valve for the kiln tail flue according to claim 5, characterized in that, A distance measuring component is provided on one side of the outer surface of the movable part. The distance measuring component is connected to the control unit. The distance measuring component is used to measure the distance between itself and the movable part and send it to the control unit. The control unit obtains the outlet opening of the wind root valve based on the distance between the distance measuring component and the movable part.

7. The air root valve for the kiln tail flue according to claim 1, characterized in that, The fixed part includes two fixed walls located above the side wall of the smoke chamber outlet. The two fixed walls are opposite each other and are both vertically arranged. The movable part is a movable wall, with two movable walls arranged opposite each other between the two fixed walls. The lower part of the movable part is connected to the fixed part through a pivot.

8. The air root valve for the kiln tail flue according to claim 1, characterized in that, A bottom support is provided at the bottom of the fixed part and the movable part, and a top connector is provided at the top of the fixed part and the movable part. The bottom support is fixed to the top of the smoke chamber outlet, and the bottom support and the top connector are respectively fixed to the fixed part. A first limiting platform is provided on the inner surface of the top connector, and the width of the first limiting platform is smaller than the width of the top connector; A second limiting platform is provided on the inner surface of the bottom support member. The second limiting platform supports the limiting plate, and the inner surface of the second limiting platform and the inner surface of the limiting plate are located on the same plane.

9. A cement kiln, characterized in that, Includes a kiln tail flue gas valve according to any one of claims 1-8.

10. A method for adjusting the opening degree of the kiln tail smoke chamber outlet, characterized in that, Includes the following steps: Install a kiln tail smoke chamber air root valve according to any one of claims 1-8 at the smoke chamber outlet; Based on the changes in the firing temperature inside the kiln and / or the content of the selected gas in the flue and / or the outlet temperature of the decomposer and / or the increase in the outlet temperature of the decomposer and / or the pressure difference before and after the decomposer, the movable part is adjusted relative to the fixed part to regulate the opening of the air root valve outlet.

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