Root valve, rotary kiln and method for adjusting air volume of necking

Abstract

The present application belongs to the technical field of valve. A kind of wind root valve, rotary kiln and necking air volume regulating method are presented.The wind root valve includes valve body, the inside of the valve body is equipped with the air channel cavity for airflow to pass through, the upper portion of the air channel cavity is used to communicate with the decomposing furnace, the lower portion of the air channel cavity is used to communicate with the smoke chamber, characterized in that, the valve body is connected with driving mechanism, the telescopic part of the driving mechanism is connected with connecting frame, the moving wall is arranged on the connecting frame, one end of the moving wall extends into the air channel cavity and controls ventilation volume by horizontal movement, the height of the moving wall is greater than or equal to 500 millimeters.The present application solves the problem that turbulence is easy to produce when adjusting the existing movable plate or movable block, overcomes the disadvantages that adjustable movable plate or movable block destroys flow field, realizes "wind tunnel" effect, and ensures the lifting effect on raw meal powder.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to an air root valve, a rotary kiln, and a method for regulating the air volume at the constriction. 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 cement precalcination production process, the decomposition furnace is the core equipment for realizing the decomposition of raw meal. Its internal core reaction process is as follows: the combustion of pulverized coal releases heat, providing energy for the decomposition of raw meal (mainly CaCO3). The raw meal needs to absorb heat and decompose into CaO and CO2 at a high temperature of around 850℃. From a process control perspective, the decomposition rate of the raw meal must reach 95% or higher to ensure the quality of subsequent clinker calcination. The movement and reaction process of the raw meal within the decomposition furnace follows a clear process path: after entering the decomposition furnace from the upper preheater, the raw meal is suspended upwards under the combined driving force of the high-temperature fan at the kiln tail, the lifting effect of the flue gas entering the bottom of the decomposition furnace from the rotary kiln smoke chamber, and the swirling effect of the tertiary air, completing the decomposition reaction in this process. The decomposed meal is collected by the final preheater and then enters the rotary kiln smoke chamber and subsequent calcination processes. The constriction connecting the rotary kiln flue chamber and the preheater is a crucial component ensuring the smooth operation of the aforementioned processes. Its core function is to serve as a channel for the flue gas from the rotary kiln combustion to enter the preheater. Simultaneously, by maintaining a suitable flue gas velocity and a stable flow field within the channel, it achieves two key objectives: first, to ensure sufficient heat exchange for the high-temperature flue gas entering the preheating and decomposition systems; and second, to support the raw meal entering the preheater, ensuring its full suspension and decomposition within the furnace. It also prevents undecomposed raw meal from directly flowing back into the rotary kiln flue chamber. If the raw meal directly enters the rotary kiln flue chamber, it will be carried by the airflow into the rotary kiln for further heat absorption and decomposition, which will not only disrupt the stability of the kiln's firing temperature and thus affect the clinker quality, but may also lead to serious production accidents in severe cases.

[0004] Theoretically, stable raw meal quantity and fineness, stable pulverized coal combustion state in the furnace, and steady-state negative pressure distribution in the precalciner are prerequisites for maintaining a stable flow field at the constriction and ensuring its functionality. However, in the actual operation of cement production lines, these key parameters are all in a state of dynamic fluctuation, and even experience short-term large fluctuations: the quantity and fineness of raw meal entering the precalciner are difficult to maintain a stable level, the pulverized coal combustion state in the furnace is constantly changing due to factors such as fuel quality and supply, and the negative pressure distribution in the precalciner also fluctuates accordingly. In recent years, in response to industry calls for carbon emission reduction and waste disposal, cement companies have successively adopted new processes such as burning alternative fuels, garbage, and hazardous waste in the precalciner, as well as adding bypass ventilation, further exacerbating the fluctuation range of the operating conditions in the precalciner and posing a greater challenge to the stability of the flow field at the constriction. When the flue gas velocity in the constriction is too low or the constriction structure cannot adapt to changes in operating conditions, its blocking and lifting effect on the raw meal powder will be significantly weakened, and under dynamic operating conditions, there is a high risk that undecomposed raw meal powder will directly enter the kiln. Currently, the smoke chamber narrowing devices used in industrial production generally suffer from the problems of a single installation method and a fixed and unadjustable connection structure: when the calcination conditions are unreasonable and adjustments are needed, the machine must be stopped for maintenance or modification, which not only makes operation difficult and adjustment accuracy low, but also poses a high safety risk and cannot accurately adapt to the demands brought about by changes in fuel conditions and fluctuations in various operating conditions.

[0005] To address the issue of the non-adjustable ventilation area at the constriction point, existing research has proposed an adjustable smoke chamber constriction scheme. This involves installing adjustable movable plates or blocks within the constriction point, changing the ventilation cross-sectional area by adjusting their positions, thereby regulating the airflow. However, this scheme has drawbacks: the linear relationship between the movable plates or blocks and the ventilation volume regulation within the rotary kiln is poor, and the edges of the movable plates or blocks generate strong turbulence, causing the airflow in the edge region to exhibit an upward-sloping turbulent state. This disrupts the stability of the flow field at the constriction point, failing to effectively lift the raw meal powder in the decomposer. Ultimately, this defect still allows a large amount of undecomposed raw meal powder to enter the rotary kiln through the smoke chamber, disrupting the stability of the kiln's firing temperature, affecting clinker quality, and potentially causing major safety accidents. Therefore, it fails to fundamentally solve the core problem of constriction function failure under dynamic operating conditions. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for regulating the airflow of a wind-root valve, a rotary kiln, and a constricted-mouth airflow. It limits the height of the movable wall to 500 mm or more, solving the problems of poor linearity and turbulence caused by existing movable plates or blocks. It overcomes the drawbacks of adjustable movable plates or blocks disrupting the flow field, achieving a "wind tunnel" effect. This makes the relationship between the movement of the movable wall and the change in airflow closer to linear, improving the controllability of wind speed adjustment and the adaptability of ventilation volume regulation to changes in operating conditions. Simultaneously, it enhances the stability of the flow field within the air duct cavity, ensuring a lifting effect on the raw material powder.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a wind root valve.

[0009] A type of air intake valve includes a valve body with an internal air duct cavity for airflow. The upper part of the air duct cavity is used to communicate with the cavity of a decomposition furnace, and the lower part of the air duct cavity is used to communicate with the cavity of a smoke chamber. The valve body is connected to a drive mechanism, and the telescopic part of the drive mechanism is connected to a connecting frame. A movable wall is arranged on the connecting frame, and one end of the movable wall extends into the air duct cavity and the ventilation volume is adjusted by horizontal movement. The height of the movable wall is greater than or equal to 500 mm.

[0010] In one implementation of the first aspect of the present invention, the valve body includes a plurality of clamping frames, each clamping frame having a horizontal channel for the connecting frame and the movable wall to pass through, a fixed column being arranged between adjacent clamping frames, and the clamping frames and the support frame of the fixed column being detachably connected.

[0011] As a further limitation of the first aspect of the invention, an upper balance wheel assembly and a lower guide wheel assembly are connected in the horizontal channel of the clamping frame. The upper balance wheel assembly contacts the upper part of the connecting frame, and the lower guide wheel assembly contacts the bottom of the connecting frame. The upper balance wheel assembly is used to balance the downward force of the moving wall so that the moving wall maintains horizontal movement in the air duct cavity.

[0012] As a further limitation of the first aspect of the present invention, the upper balance wheel assembly includes a plurality of balance wheels arranged side by side. The balance wheels are connected to the balance wheel base through a wheel frame. A core seat cavity is opened on the balance wheel base. A disc spring core seat is arranged in the core seat cavity. A disc spring is sleeved on the disc spring core seat. One end of the disc spring is connected to the disc spring core seat, and the other end of the disc spring is connected to the wheel frame.

[0013] The upper part of the core seat cavity is provided with a threaded hole. After the clamping bolt passes through the threaded hole, it contacts the top of the disc spring core seat to clamp the disc spring core seat. The balance wheel base is provided with a positioning seat. The wheel frame is rotatably connected to the positioning seat through a rotating shaft. The positioning seat is located at the front of the moving wall in the forward direction, and the core seat cavity is located at the rear of the moving wall in the forward direction.

[0014] As a further limitation of the first aspect of the present invention, the fixed column has at least one cleaning hole, and a sealing cover is closed on the cleaning hole. The sealing cover is installed on the support frame of the fixed column by a hinge rod.

[0015] As a further limitation of the first aspect of the present invention, a vertical sealing frame is connected to the support frame of the fixed column, and a flexible sealing material is arranged on the vertical sealing frame for vertical sealing between the movable wall and the fixed column when the movable wall moves.

[0016] The upper part of the air duct cavity is connected to a first flange for connection with the decomposition furnace, and the lower part of the air duct cavity is connected to a second flange for connection with the smoke chamber.

[0017] A horizontal sealing frame is connected to the clamping frame, and flexible sealing material is arranged on the horizontal sealing frame for horizontal sealing between the movable wall and the first flange and the second flange when the movable wall moves.

[0018] As a further limitation of the first aspect of the invention, when the connecting frame and the movable wall are dismantled and repaired, the horizontal sealing frame between the first flange and the movable wall is used to install the supporting protective beam to form a repair space.

[0019] In one implementation of the first aspect of the present invention, an outer cover is further included, which is connected to the outside of the valve body. The drive mechanism includes a drive motor and a transmission unit. The drive motor is connected to the outside of the outer cover, and the transmission unit is arranged in a transmission box inside the outer cover. The drive motor and the transmission unit are connected, and the transmission unit is used to control the horizontal movement of the movable wall under the drive of the drive motor.

[0020] As a further limitation of the first aspect of the present invention, the transmission box has a cooling air inlet and a cooling air outlet, and the transmission box is supplied with cooling air through the cooling air inlet to cool the transmission unit.

[0021] As a further limitation of the first aspect of the present invention, the transmission unit includes: a drive shaft, a drive sprocket, a first transmission chain, a second transmission chain, a first driven sprocket, a second driven sprocket, a first drive screw, a second drive screw, a first drive nut, and a second drive nut, wherein the first drive screw and the second drive screw are symmetrically arranged on both sides of the drive shaft.

[0022] The drive shaft is connected to the drive motor, the drive sprocket is sleeved and fixed on the drive shaft, the first transmission chain is connected to the drive sprocket and the first driven sprocket of the first drive screw respectively, and the second transmission chain is connected to the drive sprocket and the second driven sprocket of the second drive screw respectively.

[0023] Both the first drive nut and the second drive nut are connected to the connecting frame. The first drive screw is threadedly connected to the first drive nut, and the second drive screw is threadedly connected to the second drive nut. The first drive screw is rotatably connected to the first bearing in the transmission box, and the second drive screw is rotatably connected to the second bearing in the transmission box.

[0024] As a further limitation of the first aspect of the present invention, the wind root valve also includes an automatic lubrication system, which includes a lubricating oil pump. The lubricating oil pump provides intermittent lubrication of the first bearing and the second bearing when the moving wall moves through a first pipeline, and provides real-time lubrication of the first drive nut and the second drive nut when the moving wall moves through a second pipeline.

[0025] Secondly, the present invention provides a cement rotary kiln.

[0026] A cement rotary kiln includes at least a decomposition furnace, a smoke chamber, and an air root valve according to the first aspect of the present invention. The upper part of the air root valve is connected to the decomposition furnace, and the bottom part of the air root valve is connected to the smoke chamber.

[0027] Thirdly, the present invention provides a rotary kiln.

[0028] A rotary kiln includes at least a preheater and an air root valve of the first aspect of the present invention, the air root valve being connected to the bottom of the preheater.

[0029] Fourthly, the present invention provides a method for adjusting the air volume at the constriction point.

[0030] A method for regulating constricted airflow, utilizing the air root valve of the first aspect of this invention, includes the following process:

[0031] According to the rated operating conditions of the cement rotary kiln production line, the movable wall is adjusted to the initial position so that the air duct cavity forms an initial ventilation cross-sectional area that is compatible with the rated flue gas velocity.

[0032] Key parameters of the cement kiln are continuously collected. The flow field state corresponding to the raw material decomposition rate being greater than or equal to the set threshold, the kiln reaching the sintering temperature, and the rated output are used as the benchmark stable state. The benchmark thresholds of each key parameter are set according to the benchmark stable state, and the parameters collected in real time are dynamically compared with the corresponding benchmark thresholds.

[0033] When a key parameter is detected to deviate from the baseline threshold, the required adjustment amount of the ventilation cross-sectional area is calculated based on the parameter deviation, and then a moving wall adjustment command is generated to specify the moving direction and moving distance.

[0034] After receiving the adjustment command, the drive motor starts and drives the corresponding moving wall to the target position. After the moving wall moves to the target position, it continuously monitors the key parameters and makes the next adjustment according to the kiln firing situation. When the deviation of each key parameter from the corresponding threshold is less than the set threshold, it is determined that the ventilation volume in the kiln is reasonable and the wind speed in the air duct cavity can effectively support the raw material powder.

[0035] When the deviation of any key parameter from its corresponding threshold exceeds the set threshold, it is determined that the turbulence is too large and the wind speed in the air duct cavity cannot effectively lift the raw material powder. Based on the real-time feedback deviation data, a fine-tuning command is issued, and the moving wall is driven by the drive mechanism to perform a set amplitude displacement correction until the deviation of each key parameter from its corresponding threshold is less than the set threshold.

[0036] In one implementation of the third aspect of the present invention, the key parameters of the cement kiln are collected, including at least: the flue gas velocity in the air duct cavity, the pressure difference between the decomposition furnace and the smoke chamber, the negative pressure value in the decomposition furnace, the raw material powder supply amount and fineness, and the combustion temperature in the decomposition furnace.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] This invention innovatively develops a wind root valve that limits the height of the movable wall to 500 mm or more. This solves the problem of turbulence caused by the adjustment of existing movable plates or blocks, overcomes the drawbacks of adjustable movable plates or blocks disrupting the flow field, and achieves a "wind tunnel" effect. This makes the relationship between the movement of the movable wall and the change in air volume closer to linear, improving the controllability of wind speed adjustment and the adaptability of ventilation volume adjustment to changes in operating conditions. At the same time, it enhances the stability of the flow field in the air duct cavity, ensures the lifting effect on raw meal powder, avoids the direct backflow of undecomposed raw meal powder into the rotary kiln, prevents the kiln's firing temperature imbalance from affecting clinker quality, and avoids potential production safety accidents, making the production process more continuous and stable.

[0039] This invention innovatively designs the valve body as multiple clamping frames with horizontal channels. Adjacent clamping frames and the support frame of the fixed column are detachably connected. The connecting frame and the movable wall can be installed and adjusted through the horizontal channels. This solves the problems of the traditional single installation method of the smoke chamber narrowing and the fixed connection structure that cannot be flexibly adjusted. It overcomes the defects of complex and difficult maintenance and modification operations when the working conditions change, improves the flexibility of equipment installation, maintenance and modification, and allows the equipment to quickly adjust its structure according to changes in actual production conditions. It avoids long-term downtime caused by fixed structure, reduces losses caused by production interruption, and reduces the operational risks in the maintenance and modification process. It also provides convenient conditions for subsequent adaptation to different production needs.

[0040] This invention features an upper balancing wheel assembly and a lower guide wheel assembly within the horizontal channel of the clamping frame. The upper balancing wheel assembly, through the cooperation of components such as disc springs, disc spring core seats, and clamping bolts, balances the downward force of the moving wall, while the lower guide wheel assembly provides auxiliary guidance. This solves the problem of the moving wall easily slumping due to its own weight and failing to maintain horizontal movement during movement. It overcomes the defects of traditional adjustment components that cause unstable movement leading to turbulent flow fields, improves the stability and adjustment accuracy of the moving wall's movement, ensures that the airflow in the duct cavity remains regular during movement, avoids local turbulence caused by the tilting of the moving wall, ensures effective support of raw meal powder, prevents undecomposed raw meal powder from entering the rotary kiln, maintains the stability of clinker calcination quality, and enhances the safety of the production process.

[0041] This invention features a vertical sealing frame on the support frame of the fixed column and a horizontal sealing frame on the clamping frame. Flexible sealing material is arranged on both the horizontal and vertical sealing frames. Simultaneously, a support and protective beam is deployed on the horizontal sealing frame to form a maintenance space. This solves the problem of inadequate sealing during the movement of the movable wall, overcomes the shortcomings of traditional structures such as poor sealing performance and safety hazards during maintenance, and improves the sealing effect and maintenance safety of the equipment. The flexible sealing material ensures no airflow leakage during movement, maintaining a stable flow field. The design of the maintenance space makes the disassembly and maintenance of the connecting frame and the movable wall safer and more convenient, avoiding energy loss and flow field fluctuations caused by airflow leakage. It also avoids safety accidents caused by lack of protection during maintenance, reducing the risks during the maintenance process.

[0042] This invention features an outer cover connected to the outside of the valve body, isolating external air from the negative pressure environment of the decomposition furnace. The drive motor of the drive mechanism is installed on the outside of the outer cover, while the transmission unit is placed in a transmission box inside the outer cover. The transmission box solves the problem of the drive mechanism being exposed to the outside and susceptible to environmental interference. The cooling air inlet and outlet solve the problem of overheating during operation of the transmission unit. This overcomes the shortcomings of traditional drive components, such as insufficient protection and poor heat dissipation leading to frequent failures, and improves the working stability and service life of the drive mechanism. The outer cover can isolate external dust, high temperature and other interferences, and the cooling air ensures that the transmission unit operates at a suitable temperature, avoiding adjustment failures caused by environmental influences or overheating. This ensures that the air volume adjustment can respond promptly to changes in working conditions, allowing the production process to remain stable.

[0043] The transmission unit of this invention consists of a drive shaft, sprockets, chains, symmetrically arranged drive screws and drive nuts. An automatic lubrication system lubricates the bearings and drive nuts through different pipelines, solving the problems of poor transmission synchronization and rapid component wear in the drive mechanism. It overcomes the shortcomings of traditional transmission structures, such as low adjustment precision and shortened lifespan due to untimely lubrication. This improves the synchronization and accuracy of the moving wall adjustment, ensuring coordinated action of each moving wall according to instructions. Simultaneously, it reduces component wear, extends equipment lifespan, avoids flow field instability caused by transmission deviations, prevents backflow of undecomposed raw material powder, ensures clinker quality, and reduces component replacement frequency and maintenance costs, making production operation more economical and efficient.

[0044] This invention innovatively designs a method for adjusting the air volume at a narrowing point. First, the initial position of the moving wall is set according to the rated operating conditions. Key parameters are continuously collected and dynamically compared with a benchmark threshold. The adjustment amount of the ventilation cross-sectional area is calculated based on the deviation. After driving the moving wall to adjust, continuous monitoring and fine-tuning are performed. This solves the problems of existing air volume adjustments lacking dynamic adaptation, relying on manual judgment, and having low accuracy. It overcomes the shortcomings of traditional adjustments that cannot respond to fluctuations in operating conditions in a timely manner, improving the intelligence and adaptability of air volume adjustment. It allows the ventilation cross-sectional area to match changes in operating conditions in real time, ensuring that the flow field inside the decomposition furnace remains stable. This avoids insufficient decomposition of raw materials due to parameter fluctuations, prevents imbalance in the kiln's firing temperature, ensures stable clinker quality, and reduces production accidents caused by improper operating condition adaptation, thereby improving overall production efficiency and safety.

[0045] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0046] 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.

[0047] Figure 1 This is a side view of the square air intake valve provided in Embodiment 1 of the present invention;

[0048] Figure 2 Provided for Embodiment 1 of the present invention Figure 1 A cross-sectional view (AA) of the square air inlet valve shown;

[0049] Figure 3 Provided for Embodiment 1 of the present invention Figure 1 The BB cross-sectional view of the square air root valve shown;

[0050] Figure 4 This is a schematic diagram of the internal structure of the square air intake valve provided in Embodiment 1 of the present invention;

[0051] Figure 5 This is a schematic diagram of airflow when the height of the movable wall is 200 mm, as provided in Embodiment 1 of the present invention.

[0052] Figure 6 This is a schematic diagram of airflow when the height of the movable wall is 400 mm, as provided in Embodiment 1 of the present invention.

[0053] Figure 7 This is a schematic diagram of airflow when the height of the movable wall is 500 mm, as provided in Embodiment 1 of the present invention.

[0054] Figure 8 This is a schematic diagram of airflow when the height of the movable wall is 600 mm, as provided in Embodiment 1 of the present invention.

[0055] Figure 9 This is a schematic diagram of airflow when the height of the movable wall is 800 mm, as provided in Embodiment 1 of the present invention.

[0056] Figure 10 Top view of the arc-shaped air root valve provided in Embodiment 1 of the present invention Figure 1 ;

[0057] Figure 11 Top view of the arc-shaped air root valve provided in Embodiment 1 of the present invention Figure 2 ;

[0058] Figure 12 This is a schematic diagram of the clamping frame provided in Embodiment 1 of the present invention;

[0059] Figure 13 Provided for Embodiment 1 of the present invention Figure 12 The shown is a CC section view of the clamping frame;

[0060] Figure 14 Provided for Embodiment 1 of the present invention Figure 12 The clamping frame shown is a cross-sectional view at angle FF.

[0061] Figure 15 Provided for Embodiment 1 of the present invention Figure 12 The clamping frame shown is a GG cross-sectional view.

[0062] Figure 16 This is a schematic diagram of the front balance wheel provided in Embodiment 1 of the present invention;

[0063] Figure 17 Provided for Embodiment 1 of the present invention Figure 16 The AA section view of the balance wheel shown;

[0064] Figure 18 This is a schematic diagram of the clamped balance wheel provided in Embodiment 1 of the present invention;

[0065] Figure 19 Provided for Embodiment 1 of the present invention Figure 18 The AA section view of the balance wheel shown;

[0066] Figure 20 A schematic diagram of the auxiliary support roller provided in Embodiment 1 of the present invention;

[0067] Figure 21 This is a schematic diagram of the lower support roller provided in Embodiment 1 of the present invention;

[0068] Figure 22 This is a schematic flowchart of the airflow adjustment method for constriction provided in Embodiment 4 of the present invention;

[0069] The components include: 1. Movable wall; 2. Outer cover; 3. Clamping frame; 4. Upper horizontal seal; 5. Lower horizontal seal; 6. First flange; 7. Second flange; 8. Drive motor; 9. Drive shaft; 10. Drive sprocket; 11. First transmission chain; 12. Second transmission chain; 13. Transmission box; 14. Left vertical seal; 15. Right vertical seal; 16. First drive screw; 17. Second drive screw; 18. First drive nut; 19. Second drive nut; 20. Fixed column. 21. Support frame; 22. Air duct cavity; 23. Cooling air inlet; 24. Cooling air outlet; 25. Upper balance wheel assembly; 25-1. Balance wheel base; 25-2. Positioning seat; 25-3. Wheel frame; 25-4. Wheel axle; 25-5. Roller; 25-6. Self-lubricating brass bushing; 25-7. Clamping bolt; 25-8. Core seat cavity; 25-9. Disc spring core seat; 25-10. Disc spring; 26. Lower guide wheel assembly; 26-1. Auxiliary support roller; 26-2. Lower support roller. Detailed Implementation

[0070] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0071] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0072] Example 1:

[0073] The narrowing of the flue is a crucial factor determining the output of a rotary kiln. The height and ventilation area of ​​the narrowing are key parameters for product quality. The ventilation area determines the matching of air, coal, and feed, while the air velocity at height is a decisive factor in whether material collapse occurs. The narrowing is located in the middle channel between the rotary kiln's pulverized coal combustion and the precalciner's pulverized coal combustion. Therefore, the narrowing operates in an environment with unstable pulverized coal combustion and conveying, unstable combustion, and unstable feed, resulting in high temperatures (above 1000 degrees Celsius), negative pressure with fluctuations (between -100 Pa and -400 Pa), and high dust concentrations. If the narrowing height is too low, the air intake must be increased to raise the air velocity at the narrowing, inevitably increasing power and coal consumption. If the height is too high, due to pipeline conveying distance, precalciner combustion gas field, and insufficient air supply within the kiln, coal and electricity consumption will also increase, and the precalciner gas field will change, leading to hidden process problems. Changes in the combustibility of materials, changes in coal quality, and adjustments and fluctuations in the batching scheme will all place different demands on the ventilation inside the kiln. In particular, the use of alternative fuels, hazardous waste, and municipal solid waste in rotary kilns in recent years has further increased the ever-changing demand for ventilation inside the kiln.

[0074] In view of the problems existing in the current solution, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, this implementation proposes a wind tunnel valve, including a valve body with an internal air duct cavity 22 for airflow. The upper part of the air duct cavity 22 communicates with the cavity of the decomposition furnace, and the lower part communicates with the cavity of the smoke chamber. A drive mechanism is connected to the valve body, and the telescopic part of the drive mechanism is connected to a connecting frame. A movable wall is arranged on the connecting frame, with one end extending into the air duct cavity 22 and its horizontal movement regulating the ventilation volume. The height of the movable wall is greater than or equal to 500 mm. This implementation limits the minimum height of the movable wall; if the height of the movable wall is less than this minimum height during construction, the "wind tunnel" effect cannot be effectively formed. By limiting the minimum height of the movable wall, the problem of turbulence caused by the adjustment of existing movable plates or blocks is solved, the drawback of adjustable movable plates or blocks disrupting the flow field is overcome, and the "wind tunnel" effect is realized. This makes the relationship between the amount of movement of the movable wall and the change in air volume closer to linear, improves the controllability of wind speed adjustment and the adaptability of ventilation volume adjustment to changes in operating conditions, and enhances the stability of the flow field in the duct cavity 22.

[0075] In this implementation, the 500mm height of the movable wall is not a conventionally chosen value. There is a certain correlation between the ventilation area and height of the rotary kiln's constriction. The optimization strategy for finding the minimum value is as follows (taking a square valve as an example, i.e., using a square air root valve):

[0076] (1) Theoretical calculation and verification of the minimum limit of the narrowing height.

[0077] The mainstream rotary kiln specification is 4.8m × 74m (i.e., the diameter of the rotary kiln). The length is 74m), and the horizontal cross-section of the constriction is square, with the specific dimensions of the constriction being 2m × 2m.

[0078] The rotary kiln is lined with refractory bricks and has a height of If the diameter is 0.25m, then the effective ventilation area diameter inside the rotary kiln is... for:

[0079] (1);

[0080] The necking height is generally taken as the diameter of the rotary kiln. times ( The value range is 0.2~0.3), then the height of the narrowing is... for:

[0081] (2);

[0082] Right now for , It is 1.29.

[0083] Considering that increasing the height would increase energy consumption and change the flow field, based on theoretical calculations and after a large number of field measurements and production verifications, the height of the wind root valve is determined to be the lowest value obtained from formula (2) without affecting normal production. 80% of the calculation limit minimum value ,but:

[0084] Minimum limit of necking height for:

[0085] (3);

[0086] (2) The relationship between the ventilation area of ​​the constriction and the height of the constriction.

[0087] The mainstream rotary kiln specifications are 4.8m × 74m;

[0088] The commonly used standard square necking: the horizontal cross-section of the necking is square, the specific dimensions of the necking are 2m×2m, and the height is 1m;

[0089] The circular constriction is circular, with an inner diameter of 2.3m and a height of [missing information]. It is 1m.

[0090] The ventilation area of ​​the square constriction is:

[0091] (4);

[0092] The ventilation area of ​​the circular constriction is:

[0093] (5)

[0094] The ratio of the constriction height to the ventilation area is:

[0095] Square narrow opening:

[0096] (6);

[0097] Circular constriction:

[0098] (7);

[0099] in, This is the ratio of the height of the square constriction to the ventilation area. It is the ratio of the height of the circular constriction to the ventilation area.

[0100] (3) Calculation of the ventilation area and output.

[0101] Taking a square air inlet valve as an example, let's assume the ventilation area of ​​the square constriction... for ,Yield If the yield is 6000 tons, then the theoretical output per square meter is... for:

[0102] (8);

[0103] Under normal production conditions, a daily output of 5060 tons (i.e.) ), the ventilation area that needs to be reduced for:

[0104] (9);

[0105] The narrowed ventilation area is 3.373. When, substitute Required height of the air root valve for:

[0106] (10);

[0107] The narrowed ventilation area is 3.373. When, the side length is converted to that of the air root valve. for:

[0108] (11);

[0109] Based on the current actual production capacity of 6000 tons / day, the actual adjustable ventilation area range of the air inlet valve is 1.7. -2.3 Calculations show that The square horizontal cross-section is within the range of 1.7m-2.3m of the air root valve's movement, which meets the adjustment requirements.

[0110] (4) Final determination of the minimum value.

[0111] Because the height of the constriction can be partially compensated for by increasing the airflow speed at the constriction, therefore, the minimum height of the movable wall... for:

[0112] (12);

[0113] in, To adjust the coefficient, the value is generally taken between 0.86 and 0.87 based on experience. Therefore, based on the current general capacity requirements of cement rotary kilns in the industry, the minimum height of the moving wall is... Setting it to 500mm effectively avoids turbulence by setting a minimum height of 500mm, while below 500mm there is no "wind tunnel" effect.

[0114] like Figure 5, Figure 6 , Figure 7 , Figure 8 and Figure 9 The diagrams shown are airflow diagrams for moving wall 1 at heights of 200 mm, 400 mm, 500 mm, 600 mm, and 800 mm. It can be seen that when the height of moving wall 1 is 200 mm and 400 mm, the airflow cannot lift the falling powder, which does not meet the production requirements. However, when the height of moving wall 1 is above 500 mm, the powder can be effectively lifted.

[0115] In this implementation, the connecting frame is a metal structure, and the movable wall 1 is preferably cast from two types of refractory materials. The main material on the side where the connecting frame is connected is a material with higher strength and certain heat resistance, while the main material on the side closer to the air duct cavity is a material with even higher heat resistance and certain strength. Through the dual-material layered design, different parts of the movable wall can adapt to different working conditions. The connecting side relies on a high-strength material to bear the driving and supporting forces, while the air duct side relies on a high-heat-resistant material to resist the erosion of high-temperature airflow. This leverages the performance advantages of both materials, avoiding the shortcomings of a single material in terms of strength or heat resistance. This ensures the structural stability of the connection between the movable wall and the connecting frame, extends its service life in high-temperature environments, reduces the risk of deformation caused by high temperatures, and ensures the accuracy of airflow regulation.

[0116] In this implementation, preferably, the valve body includes multiple clamping frames 3, each clamping frame 3 is provided with a horizontal channel for the connecting frame and the movable wall to pass through, and a fixed column 20 is arranged between adjacent clamping frames 3. The clamping frame 3 and the support frame 21 of the fixed column 20 are detachably connected (by bolts). The clamping frame 3 provides a guiding path for the connecting frame and the movable wall through the horizontal channel. The bolt connection facilitates position calibration during installation and subsequent maintenance. This modular design makes the valve body assembly more flexible, and individual parts can be inspected without overall disassembly. This not only improves the structural strength and stability of the valve body, but also shortens the installation and maintenance cycle and reduces labor costs. At the same time, the detachable design also facilitates subsequent structural adjustments or component replacements according to needs.

[0117] In this implementation, preferably, the movable wall 1 is a rectangular movable wall (the longitudinal section includes rectangles and squares). The movable wall 1 includes at least one rectangular movable wall (the cases of one, two, or three rectangular movable walls are not shown in the figure). In this implementation, preferably, there are four rectangular movable walls, that is, it also includes a second, third, and fourth rectangular movable wall. The relatively arranged rectangular movable walls change the effective flow area of ​​the air duct cavity by moving horizontally in sync, thereby realizing air volume regulation. The rectangular movable walls are highly adaptable to the rectangular air duct cavity, which can reduce dead angles during airflow. The airflow distribution is more uniform during the regulation process, avoiding the generation of local eddies and improving the accuracy of air volume regulation. At the same time, the rectangular structure is easy to process and has a regular sealing contact surface, which can reduce the difficulty of sealing design and improve the sealing effect.

[0118] Optionally, in some other implementations, the moving wall 1 is an arc-shaped moving wall, and at least one arc-shaped moving wall is included (the cases of one, two, or three arc-shaped moving walls are not shown in the figure), such as... Figure 10 The image shows a scenario where four curved movable walls are evenly arranged along the circumference. Figure 11 The image shows a scenario with five curved movable walls evenly arranged along the circumference.

[0119] In this implementation, preferably, the fixed column 20 has at least one cleaning hole, and a sealing cover is closed on the cleaning hole. The sealing cover is installed on the support frame 21 of the fixed column 20 through a hinged rod. The cleaning hole provides a channel for cleaning the accumulated dust and scale inside and around the fixed column 20. The hinged sealing cover ensures sealing while preventing the cover from being lost or misaligned during cleaning. The internal cleaning can be completed through the cleaning hole without disassembling the fixed column 20, simplifying the maintenance process. It can promptly remove the obstruction of accumulated dust and debris to the movement of the movable wall, ensuring the stability of equipment operation, while shortening maintenance time and reducing labor intensity. The hinged design also improves the service life and sealing reliability of the sealing cover.

[0120] In this implementation, preferably, the support frame 21 of the fixed column 20 is connected to a horizontal seal (including a left vertical seal 14 and a right vertical seal 15, respectively arranged on both sides of the clamping frame 3). The left vertical seal 14 and the right vertical seal 15 have the same structure, both including a vertical seal skeleton. Flexible sealing material is arranged on the vertical seal skeleton for vertical sealing between the moving wall and the fixed column 20 when the moving wall moves (the side of the flexible sealing material that contacts the moving wall or the connecting frame is fine and fluffy, which can ensure effective sealing and avoid increasing the moving resistance of the moving wall). The vertical seal skeleton provides structural support, and the flexible sealing material adapts to the horizontal movement of the moving wall, filling the gap between the moving wall 1 and the fixed column 20, preventing airflow leakage. The vertically arranged double sealing structure forms bidirectional protection, improves sealing reliability, effectively reduces lateral leakage of airflow in the duct, ensures the accuracy of airflow adjustment, and at the same time, the flexible material avoids rigid friction with the moving wall, reduces wear, and extends the service life of the sealing components and the moving wall.

[0121] In this preferred embodiment, the upper part of the air duct cavity 22 is connected to a first flange 6 for connection with the decomposition furnace, and the lower part of the air duct cavity 22 is connected to a second flange 7 for connection with the smoke chamber. An upper horizontal seal 4 and a lower horizontal seal 5 are connected to the clamping frame 3. The upper horizontal seal 4 and the lower horizontal seal 5 have identical structures, both including a horizontal sealing skeleton. Flexible sealing material is arranged on the horizontal sealing skeleton to provide horizontal sealing between the moving wall and the first flange 6 (achieved through the upper horizontal seal 4) and the second flange 7 (achieved through the lower horizontal seal 5) when the moving wall moves. The first flange 6 and the second flange 7 achieve a stable connection between the air duct cavity and the decomposition furnace and the smoke chamber. The horizontal sealing skeleton supports the flexible material, forming a sealing barrier at the upper and lower ends of the moving wall to prevent airflow leakage along the vertical gap. The upper horizontal seal 4 and the lower horizontal seal 5 precisely match the flanges, ensuring the sealing of the connection points. This not only guarantees the robustness and sealing of the equipment connection but also achieves dynamic sealing during the movement of the moving wall, avoiding energy waste caused by high temperature conduction to the moving chamber of the connecting frame and airflow leakage. Simultaneously, it improves the negative pressure stability of the system and ensures smooth production processes.

[0122] In this preferred embodiment, when the connecting frame and movable wall are dismantled and repaired, the horizontal sealing skeleton between the first flange 6 and the movable wall 1 is used to install supporting protective beams to form a maintenance space. For example, materials such as channel steel can be inserted in rows to serve as a protective measure at the top when repairing the air root valve and smoke chamber. This measure provides a convenient method for safe maintenance and saves the workload and cost of cleaning the scale buildup in the decomposition furnace. This invention utilizes the structural strength of the horizontal sealing skeleton as a supporting foundation to install protective beams, quickly constructing a safe maintenance space without the need for additional support structures. The protective beams can block scale or debris that may fall inside the decomposition furnace, protecting the safety of maintenance personnel, greatly simplifying the pre-maintenance preparation work, shortening the maintenance cycle, avoiding the cumbersome process of large-scale scale cleaning, reducing maintenance costs, and improving the safety and efficiency of maintenance operations.

[0123] In this preferred embodiment, an outer cover 2 is also included. The outer cover 2 is connected to the outside of the valve body. The drive mechanism includes a drive motor 8 and a transmission unit. The drive motor 8 is connected to the outside of the outer cover 2, and the transmission unit is arranged in a transmission box 13 inside the outer cover 2. The drive motor 8 is connected to the transmission unit, which is used to control the horizontal movement of the moving wall under the drive of the drive motor 8. The outer cover 2 of this invention provides protection for the valve body and the transmission mechanism. The drive motor outputs power, which is converted into a horizontal driving force for the moving wall through the transmission unit, realizing mechanized control of airflow regulation. The built-in design of the transmission unit avoids interference from the external environment. The outer cover can effectively prevent dust and high-temperature radiation, protecting internal components. The mechanized drive method improves the accuracy and efficiency of airflow regulation, reduces the intensity of manual operation, and the built-in design of the transmission unit also extends its service life.

[0124] In this implementation, preferably, the transmission housing 13 has a cooling air inlet 23 and a cooling air outlet 24. Cooling air is introduced into the transmission housing 13 through the cooling air inlet 23 to cool the transmission unit. In actual operation, the cooling air enters the transmission housing 13 through the cooling air inlet 23, exchanges heat with the heat-conducting transmission components, and is then discharged from the cooling air outlet 24, forming a continuous heat dissipation cycle. This controls the operating temperature of the transmission unit. The airflow circulation can quickly remove the heat carried in by conduction, avoiding temperature accumulation and effectively preventing problems such as lubricant failure and component deformation caused by high temperature in the transmission unit. This ensures the operational stability of the transmission system, extends the service life of key components such as bearings and chains, and improves the operational reliability of the drive mechanism.

[0125] In this implementation, preferably, the transmission unit includes: a drive shaft 9, a drive sprocket 10, a first transmission chain 11, a second transmission chain 12, a first drive screw 16, a second drive screw 17, a first drive nut 18, and a second drive nut 19. The first drive screw 16 and the second drive screw 17 are symmetrically arranged on both sides of the drive shaft 9.

[0126] The drive shaft 9 is connected to the drive motor 8. The drive sprocket 10 is sleeved and fixed on the drive shaft 9. The first transmission chain 11 is connected to the drive sprocket 10 and the first driven sprocket of the first drive screw 16 respectively. The second transmission chain 12 is connected to the drive sprocket 10 and the second driven sprocket of the second drive screw 17 respectively. The first drive nut 18 and the second drive nut 19 are both connected to the connecting frame. The first drive screw 16 is threaded to the first drive nut 18. The second drive screw 17 is threaded to the second drive nut 19. The first drive screw 16 is rotatably connected to the first bearing in the transmission box 13. The second drive screw 17 is rotatably connected to the second bearing in the transmission box 13. In actual operation, the drive motor 8 drives the drive shaft 9 and drive sprocket 10 to rotate, and drives the lead screws on both sides to rotate synchronously through two transmission chains. The threaded engagement between the lead screw and the nut converts the rotational motion into linear motion, thereby driving the connecting frame and the moving wall to move horizontally. The symmetrical arrangement of the lead screws ensures that the moving wall is evenly stressed. This method of the present invention has high transmission efficiency, can realize the smooth and precise movement of the moving wall, and greatly improves the air volume adjustment accuracy. At the same time, the symmetrical structure reduces the off-center load and jamming phenomenon of the moving wall, and improves the stability and reliability of the equipment operation.

[0127] In this preferred embodiment, the wind-root valve further includes an automatic lubrication system. This system includes a lubricating oil pump. The lubricating oil pump provides intermittent lubrication to the first and second bearings during the movement of the moving wall via a first pipeline. Simultaneously, the lubricating oil pump provides real-time lubrication to the first drive nut 18 and the second drive nut 19 during the same movement. The lubricating oil pump of this invention precisely delivers lubricating oil through different pipelines based on the different operating conditions of the components. The bearings undergo intermittent lubrication to meet their low-friction requirements, while the nuts undergo real-time lubrication to address the high-frequency friction of the threaded transmission. The lubricating oil forms an oil film, reducing direct contact between components and avoiding problems of insufficient or excessive lubrication. This effectively reduces wear on bearings and threaded pairs, extends the service life of transmission components, reduces equipment downtime, lowers maintenance costs, and improves the economy and reliability of lubrication.

[0128] In this implementation, the preferred method is as follows: Figure 12 , Figure 13 , Figure 14 and Figure 15As shown, the horizontal channel of the clamping frame 3 is connected to an upper balance wheel set 25 and a lower guide wheel set 26. The upper balance wheel set 25 contacts the upper part of the connecting frame, and the lower guide wheel set 26 contacts the bottom of the connecting frame. The upper balance wheel set 25 is used to balance the downward force of the moving wall so that the moving wall can maintain horizontal movement within the air duct cavity 22. Specifically, the lower guide wheel set 26 bears the weight of the moving wall and provides horizontal guidance, while the upper balance wheel set 25 counteracts the downward force of the moving wall after it extends into the air duct cavity through upward support. The two sets of wheels work together to ensure the stability of the moving wall's movement posture. The rolling contact of the wheels reduces movement resistance and effectively avoids tilting and jamming caused by the moving wall's downward force, ensuring the accuracy of airflow adjustment. At the same time, rolling friction replaces sliding friction, reducing component wear and improving the smoothness of the moving wall's movement and the service life of the equipment.

[0129] In this implementation, preferably, the upper balance wheel assembly 25 includes multiple balance wheels arranged side by side. The balance wheels are connected to the balance wheel base 25-1 through the wheel frame 25-3. The rollers 25-5 of the balance wheels are connected to the wheel frame 25-3 through the wheel axle 25-4. A self-lubricating brass bushing 25-6 is provided between the rollers 25-5 and the wheel axle 25-4.

[0130] like Figure 16 , Figure 17 As shown, the balance wheel seat has a core seat cavity 25-8, and a disc spring core seat 25-9 is arranged inside the core seat cavity 25-8. A disc spring 25-10 is fitted on the disc spring core seat 25-9. One end of the disc spring 25-10 is connected to the disc spring core seat 25-9, and the other end of the disc spring 25-10 is connected to the wheel frame 25-3. A threaded hole is opened in the upper part of the core seat cavity 25-8. After the clamping bolt 25-7 passes through the threaded hole, it contacts the top of the disc spring core seat 25-9 to clamp the disc spring core seat 25-9. A positioning seat 25-2 is provided on the balance wheel base 25-1. The wheel frame 25-3 is rotatably connected to the positioning seat 25-2 through a rotating shaft. The positioning seat 25-2 is located at the front of the moving wall in the forward direction, and the core seat cavity 25-8 is located at the rear of the moving wall in the forward direction. The disc spring 25-10 of this invention provides continuous compensation force through elastic deformation. The clamping bolt 25-7 can adjust the compression of the disc spring 25-10, thereby adjusting the support force of the balance wheel on the moving wall and counteracting the downward force. The position design of the positioning seat 25-2 and the core seat cavity 25-8 ensures the precise application of the support force, realizing the adjustable and long-term stability of the horizontal posture of the moving wall. The self-lubricating design reduces maintenance needs. The disc spring compensation function adapts to the leveling needs of the connecting frame in cold and hot states, greatly improving the stability and service life of the equipment and reducing the maintenance frequency.

[0131] When installing the air valve, first move the movable wall horizontally to the end of the air duct cavity (until it can no longer be moved). At this point, the end of the movable wall that extends into the air duct cavity 22 will sag. Then, by tightening the clamping bolt 25-7, the wheel seat will be pressed down to generate a certain downward force to counteract the downward force of the movable wall. Figure 18 and Figure 19 As shown, the movable wall remains level at this point. Secure the clamping bolt 25-7 in its current position to ensure the wall remains level during subsequent use. After a period of use, if some wear or loosening of components occurs, the end of the movable wall may sag again (by a small amount). In this case, simply tighten the clamping bolt 25-7 again to level it.

[0132] In this implementation, preferably, the lower guide wheel assembly 26 includes an auxiliary support wheel 26-1 and a lower support wheel 26-2. The auxiliary support wheel 26-1 and the lower support wheel 26-2 are arranged at intervals (i.e., in the horizontal direction perpendicular to the moving direction of the moving wall, the auxiliary support wheel 26-1, the lower support wheel 26-2, the auxiliary support wheel 26-1, the lower support wheel 26-2, etc. are arranged sequentially). The auxiliary support wheel 26-1 includes two rollers 25-5 (including a front roller and a rear roller) arranged front and rear along the moving direction of the moving wall. Figure 20 As shown, the lower support roller 26-2 includes a roller, as... Figure 21 As shown, this enables effective guidance of the moving wall.

[0133] In this implementation, the central axes of the front roller of the auxiliary support roller 26-1 and the roller of the lower support roller 26-2 are collinear, and they are used together to guide the movement of the moving wall 1 (always bearing the weight of the moving wall 1). The rear roller of the auxiliary support roller 26-1 is in a state of no force or only partial force when the moving wall 1 moves forward (i.e. moves into the air duct cavity) (at this time, it is only in contact or disengaged). When the moving wall 1 moves backward (i.e. moves out of the air duct cavity), it bears the weight of the moving wall 1 and prevents the moving wall 1 from tilting downward when it moves backward. The collinear design of the front rollers and lower support rollers ensures guiding accuracy, while the rear rollers adaptively receive force according to the direction of movement, forming a coordinated support system with the upper balance wheel set. This comprehensively counteracts the gravity and downward force of the moving wall. The adaptive switching of the force state ensures stability under different working conditions, achieving precise horizontal guidance for the bidirectional movement of the moving wall. The combined use of the upper balance wheel set 25 and the lower guide wheel set 26 completely solves the end-sag problem, significantly improving the accuracy of airflow adjustment and the safety of equipment operation. At the same time, the coordinated support structure reduces component wear and extends the overall service life of the equipment.

[0134] Example 2:

[0135] Based on the air root valve of Embodiment 1, this embodiment also proposes a cement rotary kiln, which includes at least a decomposition furnace, a smoke chamber, and the air root valve of Embodiment 1. The upper part of the air root valve is connected to the decomposition furnace, and the bottom part of the air root valve is connected to the smoke chamber. It is mainly used for cement processing.

[0136] Example 3:

[0137] Based on the air root valve of Embodiment 1, this embodiment also proposes a rotary kiln, which includes at least a preheater and the air root valve of Embodiment 1 of the present invention, with the air root valve connected to the bottom of the preheater. The preheater of this embodiment typically adopts a multi-stage cyclone structure, utilizing the kiln tail flue gas to preheat and upgrade the material entering the kiln. The combination of the rotary kiln body (i.e., the rotating structure, which can be used for the incineration of waste or other combustible materials) and the preheater is a thermal equipment system. Its core lies in preheating the material entering the rotary kiln through the preheater to improve thermal efficiency and reduce energy consumption. Typical cyclone suspension preheaters are often used in cement clinker calcination and lime powder calcination.

[0138] Example 4:

[0139] Based on the air valve of Embodiment 1, optionally, in this embodiment, a method for adjusting the air volume at the narrowing point is also proposed. This method can achieve precise and stable adjustment of the ventilation volume under dynamic operating conditions, ensuring a raw material decomposition rate of ≥95% and stable firing process in the kiln. Specifically, such as... Figure 22 As shown, the process includes the following:

[0140] S2201: Initial position calibration and ventilation cross-sectional area preset.

[0141] (1) Determination of rated operating parameters.

[0142] Based on a rated capacity of 5,000 tons / day for a cement rotary kiln production line, the rated process parameters are defined as follows: raw material decomposition rate ≥95%, combustion temperature in the decomposition furnace is stable at 850±50℃, and rated flue gas velocity at the constriction is >25m / s (to ensure the suspension and lifting of raw material powder and avoid backflow).

[0143] (2) Setting the initial position of the moving wall.

[0144] If it is a rectangular movable wall (including at least a first rectangular movable wall and a second rectangular movable wall arranged opposite each other), it is based on the initial ventilation cross-sectional area of ​​the air duct cavity. (Adapted to rated flue gas velocity) Calculate the initial spacing: Assume the length of the duct cavity is... (Matching the interface dimensions of the decomposition furnace / smoke chamber), movable wall height (Based on the equipment design value, such as 600mm), then:

[0145] (13);

[0146] in, Adjust the rectangular moving wall to the initial spacing. ,make sure:

[0147] (14);

[0148] in, Flue gas flow rate under rated operating conditions, in meters (m³). 3 / h, This refers to the rated flue gas velocity.

[0149] If there are multiple curved movable walls, the initial diameter of the circular cross-section of the air duct cavity should be used as a reference. Calculate the initial opening angle:

[0150] (15);

[0151] The rotation angle of the curved moving wall is adjusted by the drive mechanism, so that the inner edge of each curved wall forms a circular channel with a diameter of D0, ensuring uniform airflow distribution.

[0152] (3) Equipment preheating and initial verification.

[0153] Start the kiln tail high-temperature blower and tertiary air system to put the decomposition furnace into the preheating stage. Continuously monitor the flue gas velocity in the air duct cavity, fine-tune the position of the moving wall until the flow velocity stabilizes within the rated range, record the position of the moving wall at this time as the initial reference position, and lock the initial ventilation cross-sectional area. .

[0154] S2202: Real-time acquisition of key parameters and setting of benchmark thresholds.

[0155] (1) Data acquisition equipment and frequency configuration.

[0156] Flue gas velocity inside the duct cavity: Using a Pitot static pressure tube and a differential pressure transmitter, three sampling points (upper, middle, and lower) are evenly arranged along the cross-section of the duct cavity, with a sampling frequency of 1 time / second. The average value is taken as the real-time flue gas velocity. ;

[0157] Pressure difference between the decomposer and the smoke chamber: Differential pressure transmitters are installed at the first flange (decomposer interface) and the second flange (smoke chamber interface), with a sampling frequency of 1 time / second, and recorded as follows. ;

[0158] Negative pressure value inside the decomposition furnace: A pressure sensor is installed in the middle of the decomposition furnace, and the data is collected once per second and recorded as follows. ;

[0159] Raw meal feed rate and fineness: The raw meal feed rate was calculated based on the speed of the variable frequency motor of the screw conveyor (data acquisition frequency 1 time / second), and the fineness was measured by an online laser particle size analyzer (data acquisition frequency 1 time / 30 seconds). The results were recorded separately. and ;

[0160] Combustion temperature inside the decomposition furnace: Thermocouples are installed in the combustion zone of the decomposition furnace, and the data is collected at a frequency of 1 time / second and recorded as follows. .

[0161] (2) Benchmark threshold calibration.

[0162] Once the production line is running stably (raw material decomposition rate ≥ 95%, with no fluctuations for 30 minutes), record the stable range of each parameter and set a baseline threshold, for example:

[0163] Reference flue gas velocity >25m / s;

[0164] Reference pressure difference -150~-250Pa (allowable fluctuation ±10Pa);

[0165] Reference negative pressure -200~-300Pa (allowable fluctuation ±15Pa);

[0166] Baseline raw material supply Rated supply (allowable fluctuation ±5%)

[0167] Reference fineness Rated fineness (allowable fluctuation ±2%);

[0168] Reference combustion temperature 850±50℃ (allowable fluctuation ±30℃).

[0169] S2203: Parameter deviation judgment and calculation of ventilation cross-sectional area adjustment.

[0170] (1) Dynamic comparison and deviation judgment.

[0171] The parameters collected in real time are compared with the corresponding benchmark thresholds. If any parameter exceeds the allowable fluctuation range, it is judged as "parameter deviation" and the adjustment process is triggered. If multiple parameters deviate at the same time, they are sorted according to "impact priority" (flue gas velocity > combustion temperature > pressure difference > raw material supply > fineness > negative pressure).

[0172] (2) Adjustment quantity coupling calculation.

[0173] Based on the fluid dynamics continuity equation:

[0174] (16);

[0175] in, For flue gas flow rate, For ventilation cross-sectional area, (For flue gas velocity), combined with multi-parameter coupling relationships, calculate the adjustment amount of the ventilation cross-sectional area. For example:

[0176] When a single parameter deviates:

[0177] (17);

[0178] At this point, the flue gas velocity deviates from the dominant velocity.

[0179] or,

[0180] (18);

[0181] At this point, the supply of raw materials deviates from the dominant trend.

[0182] When multiple parameters deviate:

[0183] (19);

[0184] in, , ... These are weighting coefficients; for example, when six parameters deviate, they are set according to their impact priority. , , , , , );

[0185] Adjusted ventilation cross-sectional area (constraints):

[0186] (20);

[0187] Must meet 1.7m²≤ ≤4.0m² (suitable for flow field requirements of 6000 tons / day production capacity).

[0188] (3) Generation of adjustment instructions.

[0189] Rectangular moving wall: According to Determine the direction of movement ( If ΔS is positive, the moving wall moves in the opposite direction, increasing the cross-sectional area; if ΔS is negative, it moves towards the opposite direction, decreasing the cross-sectional area. (Moving distance:)

[0190] (twenty one);

[0191] in, For the height of the movable wall ( The synchronous adjustment rate is set to 5 mm / s (to ensure that there are no sudden changes in the flow field).

[0192] S2204: Drive execution and real-time feedback adjustment.

[0193] (1) Drive mechanism linkage control.

[0194] After receiving the adjustment command, the drive motor starts at the set speed, drives the drive sprocket to rotate through the drive shaft, drives the symmetrically arranged first drive screw and second drive screw to rotate through the transmission chain, and then drives the first drive nut, second drive nut and connecting frame to move horizontally.

[0195] During execution, the automatic lubrication system is activated simultaneously: the first and second drive nuts are lubricated in real time through the second pipeline (lubricating oil pump pressure 0.3-0.5MPa), and the first and second bearings are lubricated intermittently through the first pipeline (for example, oil is supplied once every 30 seconds, with a single oil supply volume of 5ml); cooling air is introduced into the transmission box through the cooling air inlet (wind speed 1-2m / s) and discharged through the cooling air outlet, maintaining the temperature of the transmission unit ≤60℃.

[0196] (2) Ensuring the stability of the flow field during the movement process.

[0197] The upper balance wheel assembly balances the downward force of the movable wall through the preload of disc springs (preload 10kN-15kN), and the lower guide wheel assembly (auxiliary support rollers + lower support rollers arranged at intervals) provides auxiliary guidance to ensure that the horizontal movement deviation of the movable wall is ≤0.5mm / m and avoid local turbulence.

[0198] The flexible sealing materials (such as graphite braided packing) of the horizontal and vertical sealing skeletons are in real time attached to the moving wall to ensure that the airflow leakage rate is ≤1% and maintain the stability of the flow field pressure.

[0199] (3) Target position verification and fine-tuning.

[0200] After the moving wall reaches the target position, continuously monitor each key parameter for 30 seconds. If the deviation of all parameters from the baseline threshold is ≤3% (e.g., ...), the wall will be considered closed. Real-time and Deviation ≤ 0.08 m / s Real-time and If the deviation is ≤15℃, the adjustment is deemed qualified, the flow field is stable, and it can effectively support the raw material powder;

[0201] If any parameter deviates by more than ±3%, it is determined that "the disturbance has not been eliminated" and a fine-tuning instruction is generated: the rectangular moving wall is fine-tuned by ±1mm each time, with a fine-tuning interval of 5 seconds, until the deviation of all parameters is ≤3%;

[0202] Special operating condition handling: If the standard is still not met after 3 fine adjustments, activate the alarm mechanism, increase the cooling air speed to 2.5m / s, check the synchronization and sealing status of the transmission unit, and readjust after eliminating mechanical faults.

[0203] S2205: Continuous monitoring and maintenance linkage.

[0204] After adjustment, the system maintains real-time parameter acquisition and dynamic comparison, recording the position of the moving wall and flow field parameters once every hour. When the production line switches operating conditions (such as using alternative fuels or adjusting the raw material ratio), the benchmark threshold is recalibrated and the above adjustment process is repeated. If the frequency of parameter fluctuation is detected to be greater than 5 times / minute, a cleaning hole warning is triggered. The dust accumulated in the air duct cavity can be cleaned through the cleaning hole of the fixed column (the closed cover is hinged and opened) to avoid dust accumulation affecting the adjustment accuracy.

[0205] Through the above-mentioned detailed steps, the precise matching of the narrowing air volume with dynamic operating conditions is achieved, ensuring a stable flow field in the decomposition furnace, sufficient decomposition of raw materials, preventing undecomposed raw material powder from flowing back into the kiln, and ensuring clinker quality and production safety.

[0206] 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 wind-source valve, comprising a valve body, wherein the valve body has an internal air duct cavity for airflow, the upper part of the air duct cavity being for communication with a decomposition furnace, and the lower part of the air duct cavity being for communication with a smoke chamber, characterized in that, The air root valve is located at the constriction position between the flue chamber and the decomposition furnace of the rotary kiln. The valve body is connected to a drive mechanism. The telescopic part of the drive mechanism is connected to a connecting frame. The movable wall is arranged on the connecting frame. One end of the movable wall extends into the air duct cavity and the ventilation volume is adjusted by horizontal movement. The height of the movable wall is greater than or equal to 500 mm. The movable wall is cast from two refractory materials. The main material on the side connected to the connecting frame is a material with greater strength and certain heat resistance, while the main material on the side closer to the air duct cavity is a material with stronger heat resistance and certain strength. Through the dual-material layered design, different parts of the movable wall can be adapted to different working conditions. The valve body includes multiple clamping frames, each clamping frame is provided with a horizontal channel for the connecting frame and the movable wall to pass through, and a fixed column is arranged between adjacent clamping frames. The clamping frame and the support frame of the fixed column are detachably connected. The clamping frame has an upper balance wheel assembly and a lower guide wheel assembly connected in its horizontal channel. The upper balance wheel assembly contacts the upper part of the connecting frame, and the lower guide wheel assembly contacts the bottom of the connecting frame. The upper balance wheel assembly is used to balance the downward force of the moving wall so that the moving wall remains horizontal within the air duct cavity. It also includes an outer cover connected to the outside of the valve body. The drive mechanism includes a drive motor and a transmission unit. The drive motor is connected to the outside of the outer cover, and the transmission unit is arranged in a transmission box inside the outer cover. The drive motor is connected to the transmission unit, and the transmission unit is used to control the horizontal movement of the movable wall under the drive of the drive motor.

2. The air valve as described in claim 1, characterized in that, The upper balance wheel assembly includes multiple balance wheels arranged side by side. The balance wheels are connected to the balance wheel base through a wheel frame. The balance wheel base has a core seat cavity. A disc spring core seat is arranged in the core seat cavity. A disc spring is sleeved on the disc spring core seat. One end of the disc spring is connected to the disc spring core seat, and the other end of the disc spring is connected to the wheel frame. The upper part of the core seat cavity is provided with a threaded hole. After the clamping bolt passes through the threaded hole, it contacts the top of the disc spring core seat to clamp the disc spring core seat. The balance wheel base is provided with a positioning seat. The wheel frame is rotatably connected to the positioning seat through a rotating shaft. The positioning seat is located at the front of the moving wall in the forward direction, and the core seat cavity is located at the rear of the moving wall in the forward direction.

3. The air valve as described in claim 1, characterized in that, The fixed column has at least one cleaning hole, and the cleaning hole is covered with a sealing cover. The sealing cover is installed on the support frame of the fixed column by a hinge rod.

4. The air valve as described in claim 1, characterized in that, A vertical sealing frame is connected to the support frame of the fixed column, and flexible sealing material is arranged on the vertical sealing frame for vertical sealing between the movable wall and the fixed column when the movable wall moves. The upper part of the air duct cavity is connected to a first flange for connection to the decomposition furnace, and the lower part of the air duct cavity is connected to a second flange for connection to the smoke chamber. A horizontal sealing frame is connected to the clamping frame, and flexible sealing material is arranged on the horizontal sealing frame for horizontal sealing between the movable wall and the first flange and the second flange when the movable wall moves.

5. The air valve as described in claim 4, characterized in that, When the connecting frame and the movable wall are dismantled and repaired, the horizontal sealing frame between the first flange and the movable wall is used to install support and protective beams to form a repair space.

6. The air inlet valve as described in claim 1, characterized in that, The movable wall is either a rectangular movable wall or an arc-shaped movable wall.

7. The air valve as described in claim 1, characterized in that, The transmission box has a cooling air inlet and a cooling air outlet. Cooling air is introduced into the transmission box through the cooling air inlet to cool the transmission unit.

8. The air valve as described in claim 1, characterized in that, The transmission unit includes: a drive shaft, a drive sprocket, a first transmission chain, a second transmission chain, a first driven sprocket, a second driven sprocket, a first drive screw, a second drive screw, a first drive nut, and a second drive nut, wherein the first drive screw and the second drive screw are symmetrically arranged on both sides of the drive shaft; The drive shaft is connected to the drive motor, the drive sprocket is sleeved and fixed on the drive shaft, the first transmission chain is connected to the drive sprocket and the first driven sprocket of the first drive screw respectively, and the second transmission chain is connected to the drive sprocket and the second driven sprocket of the second drive screw respectively. Both the first drive nut and the second drive nut are connected to the connecting frame. The first drive screw is threadedly connected to the first drive nut, and the second drive screw is threadedly connected to the second drive nut. The first drive screw is rotatably connected to the first bearing in the transmission box, and the second drive screw is rotatably connected to the second bearing in the transmission box.

9. The air valve as described in claim 8, characterized in that, The wind root valve also includes an automatic lubrication system, which includes a lubricating oil pump. The lubricating oil pump provides intermittent lubrication of the first bearing and the second bearing when the moving wall moves through a first pipeline, and provides real-time lubrication of the first drive nut and the second drive nut when the moving wall moves through a second pipeline.

10. A cement rotary kiln, characterized in that, It includes at least a decomposition furnace, a smoke chamber, and a wind root valve as described in any one of claims 1-9, wherein the upper part of the wind root valve is connected to the decomposition furnace, and the bottom part of the wind root valve is connected to the smoke chamber.

11. A rotary kiln, characterized in that, It includes at least a preheater and the air root valve as described in any one of claims 1-9, the air root valve being connected to the bottom of the preheater.

12. A method for adjusting the air volume at a constricted opening, characterized in that, Using the air root valve according to any one of claims 1-9, Includes the following processes: According to the rated operating conditions of the cement rotary kiln production line, the movable wall is adjusted to the initial position so that the air duct cavity forms an initial ventilation cross-sectional area that is compatible with the rated flue gas velocity. Key parameters of the cement kiln are continuously collected. The flow field state corresponding to the raw material decomposition rate being greater than or equal to the set threshold, the kiln reaching the sintering temperature, and the rated output are taken as the benchmark stable state. The benchmark thresholds of each key parameter are set according to the benchmark stable state, and the parameters collected in real time are dynamically compared with the corresponding benchmark thresholds. When a key parameter is detected to deviate from the baseline threshold, the required adjustment amount of the ventilation cross-sectional area is calculated based on the parameter deviation, and then a moving wall adjustment command is generated to specify the moving direction and moving distance. After receiving the adjustment command, the drive motor starts and drives the corresponding moving wall to the target position. After the moving wall moves to the target position, the key parameters are continuously monitored and the next adjustment is made according to the kiln firing situation. When the deviation of each key parameter from the corresponding threshold is less than the set threshold, it is determined that the ventilation volume in the kiln is reasonable and the wind speed in the air duct cavity can effectively support the raw material powder. When the deviation of any key parameter from its corresponding threshold exceeds the set threshold, it is determined that the turbulence is too large and the wind speed in the air duct cavity cannot effectively lift the raw material powder. Based on the real-time feedback deviation data, a fine-tuning command is issued, and the moving wall is driven by the drive mechanism to perform a set amplitude displacement correction until the deviation of each key parameter from its corresponding threshold is less than the set threshold.

13. The method for adjusting the constricted air volume as described in claim 12, characterized in that, Key parameters of the cement kiln to be collected include at least: flue gas velocity in the air duct cavity, pressure difference between the decomposition furnace and the flue chamber, negative pressure value in the decomposition furnace, raw meal powder supply and fineness, and combustion temperature in the decomposition furnace.

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