Control method for pressure fluctuation of prestorage chamber of dry quenching furnace

Abstract

The invention relates to the technical field of dry quenching production, in particular to a dry quenching furnace pre-storage chamber pressure fluctuation control method which comprises the following steps: in a first coke loading process, controlling an elevator to lower a coke tank to a middle standing position for 30 seconds, and carrying out second coke loading after standing for 11 seconds at the middle standing position; the total time for secondary coke charging is 74 seconds; after the second coke loading is finished, the elevator transports the coke tank to move from the upper position of the cooling tower to the lifting tower in a limited manner, the furnace cover is closed twice in the moving process, the draft depth of the furnace cover inserted into the water seal tank is 50-60mm when the furnace cover is closed for the first time, the draft depth of the furnace cover inserted into the water seal tank is 160-170mm when the furnace cover is closed for the second time, and after the furnace cover is closed for the second time, the furnace cover is closed for the second time. And the pressure of the pre-storage chamber is stabilized at-10 to 30 Pa. According to the invention, the pressure of the pre-storage chamber is stabilized at-10-30Pa, which is beneficial for stabilizing a dry quenching production system.

Description

Technical Field

[0001] The invention relates to the technical field of dry quenching coke production, and in particular to a method for controlling pressure fluctuations in a pre-storage chamber of a dry quenching furnace. Background Art

[0002] The CDQ furnace pre-chamber, located at the top of the CDQ furnace, is primarily used to store CDQ coke and continuously supply heat from the CDQ coke to the cooling chamber. This reduces the time between coke loading, stabilizes the blast temperature, and ensures continuous boiler heat supply and maintains stable steam parameters. During the CDQ coke storage process, volatile components in the coke generate combustible gases such as carbon monoxide and hydrogen, which accumulate in the cone-shaped space at the pre-chamber. Therefore, pressure control in the pre-chamber is crucial to the safe and stable operation of the CDQ system.

[0003] Excessive pressure fluctuations in the pre-chamber can pose numerous risks. If the pre-chamber pressure is too high (excessive positive pressure), combustible gases and dust may escape when the furnace lid is opened for coke loading, leading to the risk of deflagration or explosion and causing environmental pollution. If the pressure is too low (excessive negative pressure), outside air may be drawn into the pre-chamber, exacerbating coke burn and reducing coke quality. Furthermore, severe pressure fluctuations can cause water vapor to be drawn into the furnace mouth, damaging the CDQ furnace refractory and affecting the long-term stable operation of the system. Therefore, maintaining stable pre-chamber pressure is critical to ensuring the safe, environmentally friendly, and efficient operation of the CDQ system.

[0004] Currently, the pre-chamber pressure in CDQ furnaces is typically controlled using a pre-chamber pressure regulating valve (installed on the heat pipe exchanger). This valve opening is adjusted to maintain a slightly negative pressure in the pre-chamber. However, existing regulating valve control methods suffer from lag, slow response, and inconvenient operation. This makes it difficult to quickly adapt to changing operating conditions, resulting in poor suppression of pressure fluctuations and impacting system stability and operational efficiency. Therefore, a more efficient and precise pre-chamber pressure regulation method is urgently needed to improve the safety and cost-effectiveness of CDQ systems. Summary of the Invention

[0005] To address the technical problems of existing CDQ furnace pre-chamber pressure regulation methods, which suffer from lag response and difficulty in effectively controlling pressure fluctuations, the present invention provides a method for controlling pressure fluctuations in the CDQ furnace pre-chamber. By rationally accelerating the coke loading time, adjusting the number of furnace cover closings, and coordinating the opening and closing of the furnace cover with the coke loading operation using an electric cylinder, the pressure fluctuations in the CDQ furnace pre-chamber are effectively reduced. After coke loading, the pre-chamber pressure is stabilized at -10 to 30 Pa, contributing to a stable CDQ production system.

[0006] The technical solutions of the present invention are as follows: A method for controlling pressure fluctuations in a pre-storage chamber of a dry quenching furnace, the method comprising: The elevator moves the coke canister containing the CDQ coke from the lifting tower to the upper limit of the cooling tower. The end time of the movement is controlled to match the end time of opening the furnace cover, and the second coke loading operation begins. During the first coke loading process, the elevator is controlled to lower the coke canister to the intermediate resting position. The first coke loading process takes 30 seconds. After 11 seconds of resting in the intermediate resting position, the second coke loading process is carried out. During the second coke loading process, the coke canister is lowered to the lower limit of the cooling tower and then lifted to the upper limit of the cooling tower in one go. The total time for the second coke loading process is 74 seconds. After the second coke loading is completed, the elevator transports the coke can from the upper limit of the cooling tower to the lifting tower. During the movement, the furnace cover is closed twice. The starting time of the movement is controlled to match the starting time of the first furnace cover closing. When the furnace cover is closed for the first time, the draft depth of the furnace cover inserted into the water seal groove is 50 ~ 60mm. When the furnace cover is closed for the second time, the draft depth of the furnace cover inserted into the water seal groove is 160 ~ 170mm. After closing the furnace cover twice, the pressure in the pre-storage chamber is stabilized at -10 ~ 30Pa.

[0007] Furthermore, when loading coke for the first time, the opening time of the bottom gate of the coke tank is controlled to be 19 seconds. When the opening angle of the bottom gate reaches 60°, the coke tank is lowered to the middle static position.

[0008] Furthermore, when loading coke for the first time, the amount of CDQ coke loaded into the CDQ furnace is 20 tons.

[0009] Furthermore, when loading coke for the second time, the opening time of the bottom gate of the coke tank is controlled to be 1 to 2 seconds. When the opening angle of the bottom gate reaches 90°, the coke tank is lowered to the lower limit position of the cooling tower.

[0010] Furthermore, during the second coke loading, the amount of CDQ coke loaded into the CDQ furnace is 10 tons.

[0011] Furthermore, when the elevator began to transport the coke can from the upper limit of the cooling tower to the lifting tower, the electric cylinder began to drive the furnace cover to close. After 41 seconds, the first closing action of the furnace cover stopped.

[0012] Furthermore, during the first closing of the furnace cover, the pre-storage chamber pressure regulating valve regulates the release of the positive pressure of 40-50 Pa generated by the first closing of the furnace cover.

[0013] Furthermore, after the first closing of the furnace cover is completed, the second closing of the furnace cover is performed after an interval of 10 seconds, and the second closing of the furnace cover is completed after 3 seconds.

[0014] Furthermore, the operating frequency of the electric cylinder used to drive the opening and closing of the furnace cover is consistent, and the operating frequency is 20 Hz.

[0015] The beneficial effects of the present invention are: The present invention provides a method for controlling pressure fluctuations in the pre-chamber of a CDQ furnace. By precisely setting the timing of the second coke loading and the two phased closures of the furnace cover, and matching the timing of the actions of the electric cylinder and the hoist, the pre-chamber pressure can be effectively stabilized within a range of -10 to 30 Pa. This solution solves the response lag problem of traditional regulating valve control. Through the coordinated control of the coke loading process and the sealing operation, it not only prevents the safety hazards caused by the overflow of combustible gas under positive pressure, but also avoids the burning of coke caused by the inhalation of air under negative pressure. At the same time, the precise synchronization of mechanical actions optimizes the coke loading efficiency and reduces the damage to refractory materials caused by pressure fluctuations, thereby improving the overall operational stability and safety of the system. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0017] Example 1 A method for controlling pressure fluctuations in a pre-storage chamber of a dry quenching furnace, the method comprising: Control the secondary coke loading time of CDQ furnace: The elevator moves the coke drum containing the dry-quenched coke to the upper limit of the cooling tower. The end time of the movement is controlled to match the end time of opening the furnace cover, and the second coke loading operation begins. During the first coke loading process, the elevator is controlled to lower the coke drum to the intermediate resting position. The first coke loading process takes 30 seconds. After 11 seconds of resting in the intermediate resting position, the second coke loading process is carried out. During the second coke loading process, the coke drum is lowered to the lower limit of the cooling tower and then lifted to the upper limit of the cooling tower at one time. The total time for the second coke loading is 74 seconds. Among them, during the first coke loading (which takes 30 seconds), the coke tank descends until it squats on the loading device. During the process of the coke tank and the loading device descending together, the bottom gate of the coke tank gradually begins to open. After 19 seconds, when the opening angle of the bottom gate of the coke tank is controlled to open to 60°, the coke tank is lowered to the middle static position. The amount of dry quenching coke poured from the coke tank into the dry quenching furnace is 20 tons.

[0018] During the second coke loading (in the process of 31 seconds), the bottom gate of the coke tank gradually opened completely from 60° (the opening angle of the bottom gate was 90°) as the loading device continued to descend, which took 1 to 2 seconds. At this time, the coke tank was lowered to the lower limit of the cooling tower, and the amount of dry quenching coke poured from the coke tank into the dry quenching furnace was 10 tons.

[0019] Adjusting the operating frequency of the electric cylinder to open the furnace cover to 20Hz can control the termination time of the action of the elevator transporting the coke can from the lifting tower to the upper limit of the cooling tower to match the termination time of the action of opening the furnace cover. That is, when adjusting the operating frequency of the electric cylinder to 20Hz, the time when the furnace cover is fully opened can be controlled to be the time when the coke can reaches the upper limit of the cooling tower from the lifting tower. At this time, there is no need to wait for the coke can to be in place after the furnace cover is opened (the coke can being in place means that the coke can reaches the upper limit of the cooling tower), which reduces the opening time of the furnace cover and also reduces the impact of air suction on the pressure fluctuation of the pre-storage chamber.

[0020] Perform two closing actions on the furnace cover: After the second coke loading is completed, the coke tank transported by the elevator moves from the upper limit of the cooling tower to the lifting tower, and at the same time, the furnace cover is closed twice. The starting time of the control movement is matched with the starting time of the first furnace cover closing action. When the furnace cover is closed for the first time, the draft depth of the furnace cover inserted into the water seal groove is 50~60mm, and the pressure in the pre-storage chamber is stabilized at 40~50Pa. When the furnace cover is closed for the second time, the draft depth of the furnace cover inserted into the water seal groove increases to 160~170mm. After closing the furnace cover twice, the pressure in the pre-storage chamber is stabilized at -10~30Pa, which prevents the water in the water seal groove from spraying out due to excessive positive pressure (greater than 30Pa) or absorbing water into the dry quenching furnace due to excessive negative pressure (less than -10Pa).

[0021] The outer edge height of the furnace cover is 360mm, a standard in the industry. Process design requirements dictate that the total draft depth for closing the furnace cover must reach 150-160cm. In this embodiment, the furnace cover is closed twice, reducing fluctuations in the pre-chamber pressure and stabilizing it at -10 to 30Pa. This prevents excessive positive pressure in the pre-chamber, which could lead to the escape of flammable gases and dust when the furnace cover is opened for the next coke loading operation, resulting in the risk of deflagration or explosion and environmental pollution. It also prevents excessive negative pressure, which could cause large amounts of outside air to be drawn into the pre-chamber, exacerbating coke burn and reducing coke quality.

[0022] By adjusting the operating frequency of the electric cylinder to close the furnace cover to 20Hz, the starting time of the elevator transporting the coke can from the upper limit of the cooling tower to the lifting tower can be controlled to match the starting time of the first furnace cover closing action. That is, when the operating frequency of the electric cylinder is adjusted to 20Hz, the furnace cover can be controlled to immediately start performing two furnace cover closing actions after the second coke loading is completed. At the operating frequency of 20Hz, the electric cylinder drives the furnace cover to move and perform the first furnace cover closing action. After 41 seconds, the first furnace cover closing action stops. The draft depth of the furnace cover inserted into the water seal groove is 50-60mm. In the process of closing the furnace cover for the first time, the positive pressure of 40-50Pa generated by the first furnace cover closing action is released and adjusted by the pre-storage chamber pressure regulating valve. After the first furnace cover closing action is completed, the second furnace cover closing action is performed after an interval of 10 seconds. After 3 seconds, the second furnace cover closing action stops. The draft depth of the furnace cover inserted into the water seal groove is 160-170mm. By controlling the operating frequency of the electric cylinder to 20Hz, it can match the above two closing actions of the furnace cover and stabilize the pressure in the pre-storage chamber at -10 ~ 30Pa.

[0023] Comparative Example 1 Before using the method for controlling pressure fluctuations in the pre-chamber of a CDQ furnace in Example 1, the operations related to secondary coking in the CDQ furnace are as follows: Fixed CDQ furnace secondary coke loading time: The elevator moved the coke drum containing the CDQ coke to the upper limit of the cooling tower before the second coke loading operation began. During the first coke loading process, the elevator was controlled to lower the coke drum to the intermediate resting position. The first coke loading process took 31 seconds. After 14 seconds of resting in the intermediate resting position, the second coke loading process began. During the second coke loading process, the coke drum was lowered to the lower limit of the cooling tower and then lifted to the upper limit of the cooling tower in one go. The total time for the second coke loading process was 85 seconds. During the first coke loading (which takes 31 seconds), the coke tank descends until it squats on the loading device. As the coke tank and the loading device descend together, the bottom gate of the coke tank gradually begins to open. After 20 seconds, when the opening angle of the bottom gate of the coke tank is controlled to open to 60°, the coke tank is lowered to the middle static position. The amount of dry quenched coke poured from the coke tank into the dry quenching furnace is 20 tons.

[0024] During the second coke loading (which takes 40 seconds), the bottom gate of the coke tank gradually opens fully from 60° (the opening angle of the bottom gate is 90°) as the loading device continues to descend. It takes 1 to 2 seconds for the coke tank to be lowered to the lower limit of the cooling tower. The amount of dry quenched coke poured from the coke tank into the dry quenching furnace is 10 tons.

[0025] Compared with the optimized Example 1, the total time of Comparative Example 1 is 85 seconds. The coke loading time is long, and the furnace cover opening time (referring to the time from the furnace cover being fully opened to the furnace cover being fully closed during the coke loading process) is also correspondingly extended. The amount of air inhaled by the CDQ furnace increases, increasing the risk of pressure fluctuations in the CDQ furnace pre-chamber.

[0026] In addition, the inventors have also experimented with adjusting the secondary coke loading time to a shorter time, for example, 72 seconds. During the first coke loading, the bottom gate of the coke tank was controlled to open to 45° and the coke tank was lowered to the middle static position. During the second coke loading, the bottom gate of the coke tank was gradually fully opened from 45°. However, due to the shortened time and the small opening angle of the first time, the total amount of dry quenched coke poured from the coke tank into the dry quenching furnace could only reach about 15 tons, increasing industrial operating costs.

[0027] Carry out a closing furnace cover action: After the second coke loading is completed, the furnace cover is closed. The draft depth of the furnace cover in the water seal groove reaches the process requirement of 150-160mm. At this time, the positive pressure of the pre-storage chamber after the furnace cover is closed reaches 200-1000Pa. The pressure in the pre-storage chamber fluctuates greatly. After the furnace cover is closed, water sprays out from the water seal groove, which is extremely unstable. Moreover, when the furnace cover is opened again next time, combustible gas and dust are likely to overflow. In addition, the inventor has also experimented with other secondary furnace cover closing operations different from Example 1: after the second coke loading is completed, the furnace cover is closed twice. The first time the furnace cover is closed, the draft depth of the furnace cover inserted into the water seal groove is 10~30mm, and the pre-storage chamber pressure is 60~100Pa. The pre-storage chamber pressure regulating valve is used to release and adjust the positive pressure of 60~100Pa generated by the first furnace cover closing action. The second time the furnace cover is closed, the draft depth of the furnace cover inserted into the water seal groove is 160~170mm. After closing the furnace cover twice, the pre-storage chamber pressure is 10~50Pa, and the positive pressure is relatively large. When the furnace cover is opened again next time, combustible gas and dust are likely to overflow.

[0028] The inventors also experimented with a three-step furnace lid closing method. In actual production, they found that closing the lid three times while it was above the water seal tank resulted in inaccurate braking and slippage of the electric cylinder, negatively impacting its lifespan and potentially causing failure with long-term use. Furthermore, closing the lid three times did not significantly improve the pressure stability of the pre-coke chamber after coke loading. After multiple manual closing tests, the positive pressure in the pre-coke chamber still exceeded 200 Pa. Therefore, considering the electric cylinder's lifespan, potential for failure later in life, and overall effectiveness, the three-step furnace lid closing method was not chosen.

[0029] Parameters of electric cylinder for fixed loading device: The electric cylinder operates at a frequency of 16 Hz. The end time of the elevator's action to move the coke can from the lifting tower to the upper limit of the cooling tower does not match the end time of the furnace cover opening action. That is, after the elevator drives the coke can from the lifting tower to the upper limit of the cooling tower, it must wait for the furnace cover to be fully opened before it can descend to begin the second coke loading. The waiting time is 10 seconds. The operating frequency of the electric cylinder is controlled at 16 Hz. The start time of the elevator's action to move the coke can from the upper limit of the cooling tower to the lifting tower matches the start time of the above-mentioned furnace cover closing action. After the furnace cover is closed, the positive pressure in the pre-storage chamber reaches 200-1000 Pa, and the pre-storage chamber pressure is unstable.

[0030] In addition, the inventors also experimented with controlling the operating frequency of the electric cylinder to be 18 Hz, and the termination time of the action of controlling the elevator to transport the coke can from the lifting tower to the upper limit of the cooling tower did not match the termination time of the action of opening the furnace cover, that is, the elevator drives the coke can from the lifting tower to the upper limit of the cooling tower, and it is necessary to wait for the furnace cover to be fully opened before it can descend to start the second coke loading, and the waiting time is 3 seconds.

[0031] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be readily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A method for controlling pressure fluctuations in a pre-storage chamber of a dry quenching furnace, characterized in that: Methods include: The elevator moves the coke canister containing the CDQ coke from the lifting tower to the upper limit of the cooling tower. The end time of the movement is controlled to match the end time of opening the furnace cover, and the second coke loading operation begins. During the first coke loading process, the elevator is controlled to lower the coke canister to the intermediate resting position. The first coke loading process takes 30 seconds. After 11 seconds of resting in the intermediate resting position, the second coke loading process is carried out. During the second coke loading process, the coke canister is lowered to the lower limit of the cooling tower and then lifted to the upper limit of the cooling tower in one go. The total time for the second coke loading process is 74 seconds. After the second coke loading is completed, the elevator transports the coke can from the upper limit of the cooling tower to the lifting tower. During the movement, the furnace cover is closed twice. The starting time of the movement is controlled to match the starting time of the first furnace cover closing. When the furnace cover is closed for the first time, the draft depth of the furnace cover inserted into the water seal groove is 50 ~ 60mm. When the furnace cover is closed for the second time, the draft depth of the furnace cover inserted into the water seal groove is 160 ~ 170mm. After closing the furnace cover twice, the pressure in the pre-storage chamber is stabilized at -10 ~ 30Pa.

2. A method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, characterized in that: When loading coke for the first time, the opening time of the bottom gate of the coke tank is controlled to be 19 seconds. When the opening angle of the bottom gate reaches 60°, the coke tank is lowered to the middle static position.

3. The method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, wherein: When loading coke for the first time, the amount of CDQ coke loaded into the CDQ furnace is 20 tons.

4. A method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, characterized in that: When loading coke for the second time, the opening time of the bottom gate of the coke tank is controlled to be 1 to 2 seconds. When the opening angle of the bottom gate reaches 90°, the coke tank is lowered to the lower limit position of the cooling tower.

5. The method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, wherein: During the second coke loading, the amount of CDQ coke loaded into the CDQ furnace is 10 tons.

6. A method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, characterized in that: When the elevator starts to transport the coke can from the upper limit of the cooling tower to the lifting tower, the electric cylinder starts to drive the furnace cover to close. After 41 seconds, the first closing action of the furnace cover stops.

7. A method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, characterized in that: During the first closing of the furnace cover, the pre-storage chamber pressure regulating valve releases and regulates the positive pressure of 40~50Pa generated by the first closing of the furnace cover.

8. The method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to claim 1, wherein: After the first closing of the furnace cover is completed, the second closing of the furnace cover is performed after an interval of 10 seconds. After 3 seconds, the second closing of the furnace cover is completed.

9. A method for controlling pressure fluctuations in a pre-chamber of a CDQ furnace according to any one of claims 1, 6, 7 or 8, characterized in that: The operating frequency of the electric cylinder used to open and close the furnace cover is consistent, which is 20Hz.