Method for automatically controlling stopper rod to change water gap of slab continuous casting machine

Abstract

The invention relates to the technical field of production control processes of iron metallurgy continuous casting billets, and particularly discloses a method for automatically controlling a stopper rod to change a water gap of a slab continuous casting machine, which comprises the following steps of: designing a stopper rod control system of a slab crystallizer, and connecting and arranging a control button and a corresponding indicator lamp; water gap replacement preparation: the system automatically enters a preparation state; when an indicating lamp is in a quick flashing state, an automatic nozzle changing function state is started; the stopper rod control system is powered off, the stopper rod automatically returns and is closed under the action of molten steel suction force and the dead weight of the stopper rod, and after the stopper rod is closed, the system pre-presses downwards by 1 mm; starting an oil cylinder to change a water gap; rod opening operation: after the water gap is replaced, the system enters an automatic control state after the stopper rod is opened for 1 second; according to the method, the fluctuation quantity and the unsteady state time of the liquid level of the crystallizer are effectively controlled, production accidents caused by difference of operators and non-standard operation skills are avoided, the process is simple, the maintenance and operation cost is low, and the working efficiency is high.

Description

Technical Field

[0001] The invention relates to the technical field of production control technology for continuous casting slabs in iron and steel metallurgy, and in particular to a method for automatically controlling a stopper rod water changing port of a slab continuous casting machine. Background Art

[0002] The traditional process of replacing the submerged nozzle of the slab continuous casting machine is as follows: ① adjust the casting machine to the appropriate casting speed, ② turn off the stopper rod control system and change to manual control of the stopper rod, ③ manually control the stopper rod to close and open, and at the same time operate the hydraulic cylinder to open the new nozzle and remove the old nozzle, ④ install the blind plate and switch to automatic control of the stopper rod after the liquid level stabilizes, and the nozzle replacement operation is completed.

[0003] During the water inlet change process, the crystallizer liquid level control needs to be switched to manual operation first. During the manual control process, the non-steady-state casting time takes at least 70 seconds and requires skilled workers to operate, otherwise production accidents may occur due to large fluctuations in the liquid level.

[0004] Therefore, in the process of continuous casting, changing the nozzle requires experienced staff to operate, and the billet with the nozzle changed generally needs to be taken offline for cold inspection or finishing before it can be sent to rolling. To address this problem, a process flow is provided that can automatically control the closing and opening of the stopper rod when changing the nozzle to effectively control the non-steady-state time. This is to solve the problem that the mold liquid level control in the process of changing the nozzle needs to be manually controlled to close and open the stopper rod, which is unstable and causes serious fluctuations in the mold liquid level, resulting in an increased probability of internal inclusions and surface cracks in the billet, which seriously affects the hot charging of the billet and the mechanical properties of the steel. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for automatically controlling the stopper rod and water inlet replacement of a slab continuous casting machine, which includes process modules such as water inlet replacement preparation, giving a stopper rod closing signal, and giving a stopper rod opening signal.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for automatically controlling the plug rod water outlet of a slab continuous casting machine, comprising the following steps:

[0007] S1. Design the slab crystallizer stopper rod control system and connect and set the control buttons and corresponding indicator lights;

[0008] S2. Preparation for changing nozzle: When the pulling speed is controlled between 0.7-0.95m / min and the system is in automatic control state, the system automatically enters the preparation state;

[0009] S3, enable the automatic water change port function: when the automatic water change port indicator light is flashing slowly, press and hold the "enable automatic water change port" function button for 1 second, the indicator light is in a fast flashing state, and the automatic water change port function state is entered;

[0010] S4, rod closing operation: the stopper rod control system is powered off, and the stopper rod automatically returns to its original position and closes under the action of the molten steel suction and the deadweight of the stopper rod. After the stopper rod is closed, the system pre-presses downward by 1mm;

[0011] S5, start the oil cylinder water change port: confirm that step S4 is completed and then start the water change port operation;

[0012] S6, plug opening operation: After the water inlet is replaced, the system enters the automatic control state after the plug is opened for 1 second.

[0013] Specifically, the control button in step S1 is an "automatic water port change" button, the "automatic water port change" button and the corresponding indicator light are installed on the hanging operation box, and the "stopper rod close" button and the "stopper rod open" button are installed on the operating handle.

[0014] Specifically, after the automatic water change port indicator light of the slab crystallizer stopper control system in step S2 enters a slow flashing state, the system automatically enters a ready state.

[0015] Specifically, the rod closing operation in step S3 is to click the "rod closing" button on the operating handle after all preparations are completed, and the rod closing control system is powered off. The whole process takes 1.5 seconds. When the system closes the rod, the crystallizer setting liquid level automatically drops to a certain position.

[0016] Specifically, the liquid level of the crystallizer automatically drops to a certain position which is calculated and set according to the current set liquid level, with a maximum drop of 3 cm. The liquid level of the crystallizer will not be lower than the position before the automatic slag changing line is started.

[0017] Specifically, after the nozzle is replaced in step S6, the "stopper rod open" button of the operating handle is clicked, and the stopper rod is opened to the position +2mm before the closing position of the stopper rod.

[0018] The present invention has the following beneficial effects:

[0019] The method for automatically controlling the stopper rod to change the water inlet of a slab continuous casting machine designed by the present invention can automatically control the closing of the stopper rod to control the liquid level of the crystallizer during the process of replacing the submerged water inlet of the slab continuous casting machine in the iron and steel metallurgical industry, and can effectively control the fluctuation amount and non-steady-state time of the liquid level of the crystallizer, thereby avoiding production accidents caused by differences in operating personnel and inadequate operating skills.

[0020] The method for automatically controlling the stopper rod water outlet of the slab continuous casting machine designed by the present invention has a simple process, mainly involves modifying the stopper rod control program, requires little hardware investment, has low maintenance and operation costs, and has high work efficiency, so it is suitable for popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of a method for automatically controlling the plug rod to change the water outlet of a slab continuous casting machine.

[0022] Figure 2 This is a diagram of the liquid level fluctuation at the water changing port of the manually controlled plug rod.

[0023] Figure 3 It is a diagram of the liquid level fluctuation at the water changing port of the automatic control plug rod. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely further describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] like Figure 1-Figure 3 As shown, when replacing the immersed nozzle of the slab continuous casting machine, the manual control of closing and opening of the stopper rod is unstable and the liquid level of the crystallizer fluctuates seriously, which leads to an increased probability of internal inclusions and surface crack defects in the casting billet, seriously affecting the hot charging of the casting billet and the mechanical properties of the steel. A method for automatically controlling the stopper rod to change the water nozzle of the slab continuous casting machine is designed, including process modules such as nozzle replacement preparation, giving a stopper rod closing signal, and giving a stopper rod opening signal.

[0026] Design a slab crystallizer stopper control system, connect and set control buttons and corresponding indicator lights, realize the stopper closing and opening control curve that imitates manual replacement of the immersion nozzle, realize the automatic closing and opening of the stopper function, and install the "automatic water port change" button and corresponding indicator light on the hanging operation box, and install the "stopper closing" and "stopper opening" buttons on the operating handle. The operation steps are as follows:

[0027] 1. Preparation for changing the water inlet: When the pulling speed is controlled between 0.7-0.95m / min and the system is in automatic control, the automatic water inlet change indicator of the slab crystallizer plug control system enters the slow flashing state, and the system automatically enters the preparation state.

[0028] 2. Enable the automatic water change function: When the automatic water change indicator light is flashing slowly, press and hold the "Enable automatic water change function button" for 1 second, and the indicator light will flash quickly, entering the automatic water change function state;

[0029] 3. Rod closing operation: After all preparations are done, click the "Rod Closing" button on the operating handle, the stopper control system is powered off, and the stopper automatically returns to its original position and closes under the suction of the molten steel and the deadweight of the stopper. After the stopper is closed, the system pre-presses downward by 1mm (the pre-pressing amount can be adjusted according to the manufacturer's stopper erosion). The whole process takes 1.5 seconds. When the system closes the rod, the crystallizer set liquid level automatically drops to a certain position. The crystallizer liquid level automatically drops to a certain position based on the current set liquid level. The maximum drop is 3 cm, and the crystallizer liquid level will not be lower than the position before the automatic slag line is started.

[0030] 4. Start the oil cylinder water change port: After confirming that step 3 is completed, proceed with the water change port operation.

[0031] 5. Opening operation: After the nozzle is replaced, click the "opening stopper" button on the operating handle, and the stopper will be opened to the position before the closing stopper + 2mm (the increase can be adjusted according to the cross section). After the stopper is opened for 1 second (the time can be adjusted according to the cross section), the system enters the automatic control state.

[0032] The present invention realizes the process flow of automatically controlling the plug rod to change the submerged nozzle of the slab continuous casting machine, thereby reducing the non-steady-state casting time caused by changing the nozzle of the casting machine, and achieving the purpose of standardized operation of changing the nozzle. The process flow of automatically controlling the plug rod to change the nozzle of the slab continuous casting machine can reduce the non-steady-state casting time caused by changing the submerged nozzle of the casting machine, reduce the risk of inclusion and crack rate of the casting, and improve the product qualification rate.

[0033] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0034] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A method for automatically controlling the plug rod water outlet of a slab continuous casting machine, characterized in that: The following steps are involved: S1. Design the slab crystallizer stopper rod control system and connect and set the control buttons and corresponding indicator lights; S2. Preparation for changing nozzle: When the pulling speed is controlled between 0.7-0.95m / min and the system is in automatic control state, the system automatically enters the preparation state; S3, enable the automatic water change function: when the automatic water change indicator light is flashing slowly, press and hold the "Enable automatic water change function button" for 1 second, the indicator light will flash quickly, and the automatic water change function will be enabled; S4, rod closing operation: the stopper rod control system is powered off, and the stopper rod automatically returns to its original position and closes under the action of the molten steel suction and the deadweight of the stopper rod. After the stopper rod is closed, the system pre-presses downward by 1mm; S5, start the oil cylinder water change port: confirm that step S4 is completed and then start the water change port operation; S6, plug opening operation: After the water inlet is replaced, the system enters the automatic control state after the plug is opened for 1 second.

2. The method for automatically controlling the stopper rod water outlet of a slab continuous casting machine according to claim 1, characterized in that: The control button in step S1 is an "automatic water port change" button, which and a corresponding indicator light are mounted on a hanging operating box, and a "stopper rod close" button and a "stopper rod open" button are mounted on the operating handle.

3. The method for automatically controlling the stopper rod water outlet of a slab continuous casting machine according to claim 1, characterized in that: After the automatic water change port indicator light of the slab crystallizer stopper control system in step S2 enters a slow flashing state, the system automatically enters a ready state.

4. The method for automatically controlling the stopper rod water outlet of a slab continuous casting machine according to claim 2, characterized in that: The rod closing operation in step S3 is to click the "rod closing" button on the operating handle after all preparations are completed, and the rod closing control system is powered off. The whole process takes 1.5 seconds. When the system closes the rod, the crystallizer setting liquid level automatically drops to a certain position.

5. The method for automatically controlling the stopper rod water outlet of a slab continuous casting machine according to claim 4, characterized in that: The crystallizer liquid level automatically drops to a certain position which is calculated and set according to the current set liquid level, with a maximum drop of 3 cm. The crystallizer liquid level will not be lower than the position before the automatic slag changing line is started.

6. The method for automatically controlling the stopper rod water port changing of a slab continuous casting machine according to claim 2, characterized in that: After the nozzle replacement in step S6 is completed, the "stopper rod open" button of the operating handle is clicked, and the stopper rod is opened to the position + 2mm before the closing position of the stopper rod.

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