Online identification method and system for stopper nozzle blockage in continuous casting process

Abstract

The invention discloses an online identification method for stopper nozzle blocking in the continuous casting process. The method comprises the steps that 100, the stopper argon back pressure measured value pi at each moment in a set time window tn in the continuous casting process is collected in real time; 200, on the basis of the stopper rod argon back pressure measured value pi at each moment, the range delta py of the maximum value and the minimum value of stopper rod argon back pressure in the time window tn is obtained; 300, the range delta py is compared with a set range first threshold value delta pmax1, and if delta py is larger than or equal to delta pmax1, primary early warning is output; and in the continuous casting process, the time window tn is moved, and the steps 100-300 are repeatedly executed till the casting process is finished. According to the online identification method for stopper rod water gap blocking in the continuous casting process, stopper rod head or water gap blocking can be predicted in advance, and accidents are avoided.

Description

Technical Field

[0001] This invention relates to a detection method and system, and more particularly to an online identification method and system for plug nozzle blockage. Background Technology

[0002] In continuous casting, the stopper rod is one of the important flow control elements, controlling the flow rate of molten steel from the tundish to the crystallizer. When casting steel grades, especially aluminum deoxidation and rare earth treated ultra-low carbon steel grades, stopper rod nodules are prone to forming.

[0003] After the stopper rod forms nodules, it affects the smooth pouring of molten steel into the crystallizer. On the one hand, it restricts the increase in the number of consecutive castings, and in severe cases, it may be necessary to replace the submerged entry nozzle or cause unplanned casting stoppage accidents. On the other hand, the nodule products will be carried into the molten steel or float to the protective slag under the flushing of the molten steel. After being captured by the solidified billet, they will form large particles of inclusions, which will affect the quality of the billet.

[0004] To address this issue, inert gas—argon—can be blown into the stopper rod head, the tundish top nozzle, and the inner wall of the submerged entry nozzle in the mold during continuous casting billet production. The primary purpose is to prevent inclusions in the molten steel from adhering to and accumulating on these surfaces, thus preventing blockages. The argon flow rate directly impacts the anti-blocking effect on the submerged entry nozzle and the liquid level fluctuations within the mold. The ideal argon flow rate must ensure both effective anti-blocking while preventing the molten steel from being entrained by protective slag.

[0005] Because lumps easily form on the stopper head and nozzle, and these lumps are difficult to observe, they can be observed by adjusting the stopper opening. Under the same cross-sectional area and casting speed, if the stopper opening needs to be continuously increased to maintain a stable liquid level in the crystallizer, it indicates that casting is not smooth and lumps have formed. Existing patent literature already addresses stopper head and nozzle blockage.

[0006] For example, Chinese patent document CN117047093A, published on November 14, 2023, entitled "A Method for Judging and Handling the Degree of Blockage of Tundish Nozzle in Slab Continuous Casting," discloses a method for judging and handling the degree of blockage of tundish nozzle in slab continuous casting. This method judges the blockage of the nozzle by observing the changes in the tundish nozzle, the liquid level in the crystallizer, and the pouring handle in real time, and judges the degree of blockage of the tundish nozzle by the changes in the stopper rod opening, the liquid level in the crystallizer, and the pouring handle, thereby taking corresponding continuous casting measures to reduce risks, reduce losses, and promote smooth production.

[0007] For example, Chinese patent document CN113134587A, published on July 20, 2021, entitled "A Method for Judging Bottleneck Blockage and Dissolution by Changing Trend of Stopper Rod Opening Degree", discloses a method for judging bottleneck blockage and dissolution by changing trend of stopper rod opening degree. This method judges bottleneck blockage and dissolution by changing trend of stopper rod opening degree. These methods determine the degree of stopper rod blockage by changing the opening degree of the stopper rod.

[0008] However, by the time the stopper rod opening changes, blockage has already occurred. How to detect signals to provide early warning before blockage occurs and implement appropriate process measures is a problem not addressed in existing technologies. Summary of the Invention

[0009] One of the objectives of this invention is to provide an online identification method for stopper head blockage in continuous casting process. This method can predict blockage of the stopper head or nozzle in advance and avoid accidents.

[0010] To achieve the above objectives, this invention proposes an online identification method for stopper nozzle blockage in continuous casting processes, comprising the following steps:

[0011] 100: Real-time acquisition of the set time window t during continuous casting process n Measured value p of argon back pressure of stopper at each moment i ;

[0012] 200: Based on the measured value of the argon back pressure of the stopper rod at each time point p i Get the time window t during this period n The range Δp between the maximum and minimum argon back pressure of the inner plug rod y ;

[0013] 300: The range Δp y The range first threshold Δp max1 Compare, if Δp y ≥Δp max1 If so, a primary warning will be output;

[0014] During continuous casting, the time window t is moved. n Repeat steps 100-300 above until the casting process is complete.

[0015] This invention provides online identification and early warning of stopper rod nozzle blockage based on changes in argon back pressure. Specifically, during the initial casting stage, the argon back pressure gradually increases from 0, and after a period of casting, such as 3-4 minutes, it enters a stable phase where the average argon back pressure is the initial average value. As casting time increases, oxidation products accumulate on the inner walls of the stopper head and nozzle, affecting the flow field of the molten steel and causing the casting system to enter an unstable stage. At this point, the stopper back pressure gradually increases to p. i On the other hand, periodic waveform changes will occur. Based on this, the present invention uses the maximum back pressure p. Hi and minimum value p Li The range Δp y (Δp y =|p Hi -p Li |) is used to characterize the fluctuation of back pressure. As the casting time increases, Δp y The value gradually increases, indicating that nodule formation is occurring and gradually worsening. Therefore, this invention is designed so that the range of back pressure Δp... y Exceeding the set first threshold Δp of the range max1 At that time, a preliminary warning was issued.

[0016] Furthermore, in the online identification method for stopper nozzle blockage in the continuous casting process described in this invention:

[0017] Step 200 also includes: based on the measured value p of the stopper rod argon back pressure at each time point. i Get the time window t during that period n Average value of argon back pressure in the inner plug rod

[0018] Step 300 also includes: adjusting the range Δp y The second threshold of the range Δp max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning will be issued.

[0019] In this embodiment, the invention issues a primary warning for moderate nodulation, and in this case, an intermediate warning is issued for more severe nodulation as casting time increases. The intermediate warning requires comparison of the range and the average value of the stopper rod argon back pressure. Two indicators.

[0020] Furthermore, in the online identification method for stopper nozzle blockage in the continuous casting process described in this invention, step 300 further includes:

[0021] The range Δp y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked.

[0022] As casting time increases, nodules may form, potentially causing nozzle blockage. Therefore, in this implementation, a nozzle blockage alarm is issued for nodules that may lead to blockage. The nozzle blockage alarm also requires comparison of the range and the average value of the stopper rod argon back pressure. Two indicators.

[0023] Furthermore, in the online identification method for stopper nozzle blockage in the continuous casting process described in this invention, each threshold satisfies at least one of the following conditions: (Note: This threshold range varies greatly from device to device and has no specific meaning. It can only be used as an implementation example.)

[0024] The first threshold of the range Δp max1 5-10 kPa;

[0025] Range second threshold Δp max2 10-20 kPa;

[0026] The third threshold of the range Δp max3 10-30 kPa;

[0027] The average first threshold Δp1 is 15-40 kPa;

[0028] The average second threshold Δp2 is 40-200 kPa.

[0029] Furthermore, in the online identification method for stopper nozzle blockage in the continuous casting process described in this invention, the time window t n The value range is 60-240s.

[0030] Another objective of this invention is to provide an online identification system for stopper head blockage in continuous casting processes. This system can predict blockage of the stopper head or nozzle in advance, thus preventing accidents from occurring.

[0031] To achieve the above objectives, the present invention provides an online identification system for stopper nozzle blockage in continuous casting processes, comprising the following steps:

[0032] The data acquisition module collects data in real time within a set time window t during the continuous casting process. n Measured value p of argon back pressure of stopper at each moment i ;

[0033] The difference module is based on the measured value p of the argon back pressure of the stopper at each time step. iGet the time window t during this period n The range Δp between the maximum and minimum argon back pressure of the inner plug rod y ;

[0034] The alarm module will measure the range Δp y The range first threshold Δp max1 Compare, if Δp y ≥Δp max1 If so, a primary warning will be issued.

[0035] Furthermore, in the online identification system for stopper nozzle blockage in the continuous casting process described in this invention, wherein:

[0036] The difference module is also based on the measured value p of the stopper argon back pressure at each moment. i Get the time window t during that period n Average value of argon back pressure in the inner plug rod

[0037] The alarm module will also include the range Δp y The second threshold of the range Δp max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning will be issued.

[0038] Furthermore, in the online identification system for stopper nozzle blockage in the continuous casting process described in this invention, the alarm module will also detect the range Δp. y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked.

[0039] Furthermore, in the online identification system for stopper nozzle blockage in the continuous casting process described in this invention, each threshold satisfies at least one of the following:

[0040] The first threshold of the range Δp max1 5-10 kPa;

[0041] Range second threshold Δp max2 10-20 kPa;

[0042] The third threshold of the range Δp max3 10-30 kPa;

[0043] The average first threshold Δp1 is 15-40 kPa;

[0044] The average second threshold Δp2 is 40-200 kPa.

[0045] Compared with existing technologies, the online identification method and system for stopper nozzle blockage in continuous casting processes described in this invention have the following advantages and beneficial effects:

[0046] The online identification method for stopper head blockage in continuous casting process described in this invention can predict stopper head or nozzle blockage in advance and avoid accidents.

[0047] The online identification system for stopper nozzle blockage in continuous casting process described in this invention requires no additional equipment, is easy to operate, and has wide applicability, making it suitable for various production lines. Attached Figure Description

[0048] Figure 1 The flowchart illustrates the steps of one embodiment of the online identification method for stopper nozzle blockage in the continuous casting process according to the present invention.

[0049] Figure 2 The diagram shows the architecture of the online identification system for stopper nozzle blockage in the continuous casting process according to one embodiment of the present invention. Detailed Implementation

[0050] The following will further describe the online identification method and system for stopper nozzle blockage in the continuous casting process according to specific embodiments and accompanying drawings of the present invention. However, this description does not constitute an improper limitation of the present invention.

[0051] Figure 1 The flowchart illustrates the steps of one embodiment of the online identification method for stopper nozzle blockage in the continuous casting process according to the present invention.

[0052] like Figure 1 As shown, the online identification method for stopper rod blockage in the continuous casting process according to the present invention includes the following steps:

[0053] 100: Real-time acquisition of the set time window t during continuous casting process n Measured value p of argon back pressure of stopper at each moment i .

[0054] In some implementations, an argon pressure gauge and flow meter are installed in the stopper rod argon system to collect the measured value p of the stopper rod argon back pressure during the continuous casting process in real time. iBased on the measured value p of the argon back pressure of the stopper rod collected at each time point. i This allows us to obtain the measured value p of the argon back pressure of the stopper rod. i A curve that changes over time.

[0055] In some implementations, the time window t n The value can range from 60 to 240 seconds; for example, in a specific instance, it can be 100 seconds.

[0056] 200: Based on the measured value of the argon back pressure of the stopper rod at each time point p i Get the time window t during this period n The maximum value p of the argon back pressure of the inner plug rod Hi and minimum value p Li The range Δp y , Δp y =|p Hi -p Li |

[0057] Simultaneously, it can also be based on the measured value p of the stopper rod argon back pressure at each moment. i Get the time window t during that period n Average value of argon back pressure in the inner plug rod

[0058] 300: The range is compared with the set first threshold value Δp. max1 Compare, if Δp y ≥Δp max1 If the range is not specified, a primary warning is output. In some implementations, the first threshold value Δp is used. max1 It can be set to 5-10 kPa. In a specific example, the first threshold of the range is Δp. max1 It can be set to 5 kPa.

[0059] In some implementations, the range Δp can also be further... y The second threshold of the range Δp max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning is output. In some implementations, the second threshold Δp of the range is used. max2 It can be set to 10-20 kPa; the first threshold for the average value Δp1 can be set to 15-40 kPa. In a specific example, the second threshold for the range Δp... max2It can be set to 10 kPa; the average first threshold Δp1 can be set to 15 kPa.

[0060] In some implementations, the range Δp can also be further... y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked. In some implementations, the third threshold value Δp is used. max3 The second threshold for the average value, Δp2, can be set to 10-30 kPa; the third threshold for the range, Δp2, can be set to 40-200 kPa. In a specific example, the third threshold for the range, Δp... max3 It can be set to 20 kPa; the average second threshold Δp2 can be set to 40 kPa.

[0061] During continuous casting, the time window t is shifted. n Repeat steps 100-300 above until the casting process is complete.

[0062] The above-mentioned discrimination steps are used in this invention because: this invention uses changes in argon back pressure to perform online identification and early warning of stopper rod nozzle blockage. Specifically, during the initial casting stage, the argon back pressure gradually increases from 0, and after a period of casting, such as 3-4 minutes, it enters a stable stage. The average value of the argon back pressure at this time is the initial average value. In a specific example, the initial average It is 10.2 kPa.

[0063] As casting time increases, oxidation products accumulate on the inner walls of the stopper head and nozzle, affecting the flow field of the molten steel and causing the casting system to enter an unstable stage. At this point, the stopper back pressure gradually increases to p. i On the other hand, periodic waveform changes will occur. Based on this, the present invention uses the maximum back pressure p. Hi and minimum value p Li The range Δp y (Δp y =|p Hi -p Li |) is used to characterize the fluctuation of back pressure. Once Δp is obtained... y This indicates that a tumor has already formed, but it is still in its early stages and there is no need to issue a warning yet.

[0064] As the casting time increases, the nodule formation becomes more and more severe. At this point... Although the change is not significant, the range Δp y It begins to increase. Therefore, this invention is designed so that the range Δp of the back pressure increases. y Exceeding the set first threshold Δp of the range max1 At that time, a preliminary warning was issued.

[0065] As the casting time increases, the nodule formation becomes more severe. An increase occurred; for example, in one specific case, it increased to 35 kPa, exceeding the first threshold of the average value Δp1 = 15 kPa. Simultaneously, the range also increased to 15 kPa, exceeding the second threshold of the range Δp. max2 =10 kPa. Under these conditions, the present invention issues a medium-level warning for more severe nodules.

[0066] As casting time increases further, nodules may form, potentially causing nozzle blockage. For example, in one specific case... The Pa Pa increased to 60 kPa in a short period of time, exceeding the second threshold of the average value Δp2 = 40 kPa. At the same time, the range also increased to 20 kPa, exceeding the second threshold of the range Δp. max3 =10 kPa. Therefore, in this implementation, a nozzle blockage alarm is issued for nodules that may cause blockage.

[0067] In another embodiment of the present invention, an online identification system for stopper nozzle blockage in continuous casting process is also provided.

[0068] Figure 2 The diagram shows the architecture of the online identification system for stopper nozzle blockage in the continuous casting process according to one embodiment of the present invention.

[0069] like Figure 2 As shown, in some embodiments, the online identification system for stopper nozzle blockage in the continuous casting process may include:

[0070] Data acquisition module 101 acquires data in real time within a set time window t during the continuous casting process. n Measured value p of argon back pressure of stopper at each moment i .

[0071] The difference module 102 is based on the measured value p of the argon back pressure of the stopper at each time step. i Get the time window t during this period n The range Δp between the maximum and minimum argon back pressure of the inner plug rod y .

[0072] In some specific implementations, the difference module 102 is also based on the measured value p of the stopper argon back pressure at each time step. i Get the time window t during that periodn Average value of argon back pressure in the inner plug rod

[0073] Alarm module 103, which will measure the range Δp y The range first threshold Δp max1 Compare, if Δp y ≥Δp max1 If so, a primary warning will be issued.

[0074] In some implementations, the alarm module 103 will also include the range Δp y The second threshold of the range Δp max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning will be issued.

[0075] In some implementations, the alarm module 103 will also include the range Δp y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked.

[0076] In this invention, the data acquisition module 101, the difference module 102, and the alarm module 103 can be implemented in any suitable manner. For example, they can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) that can be executed by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicon Labs C8051F320.

[0077] Furthermore, those skilled in the art will recognize that, besides implementing the controller using purely computer-readable program code, the method steps can be logically programmed to enable the modules to perform the same function in the form of logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a module can be considered a hardware component, and the devices included within it for implementing various functions can also be considered structures within that hardware component. Alternatively, the devices for implementing various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0078] It should be noted that the prior art portion of the protection scope of this invention is not limited to the embodiments given in this application. All prior art that does not contradict the solution of this invention, including but not limited to prior patent documents, prior publications, prior public uses, etc., can be included in the protection scope of this invention.

[0079] Furthermore, the combination of the technical features in this case is not limited to the combination methods described in the claims of this case or the combination methods described in the specific embodiments. All technical features described in this case can be freely combined or combined in any way, unless they contradict each other.

[0080] It should also be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A method for online identification of nozzle blockage in a continuous casting process, characterized in that, Including the following steps: 100: Real-time acquisition of the set time window t during continuous casting process n Measured value p of argon back pressure of stopper at each moment i ; 200: Based on the measured value of the argon back pressure of the stopper rod at each time point p i Get the time window t during this period n The range Δp between the maximum and minimum argon back pressure of the inner plug rod y ; 300: The range Δp y The first threshold of the range Δp max1 Compare, if Δp y ≥Δp max1 If so, a primary warning will be output; During continuous casting, the time window t is moved. n Repeat steps 100-300 above until the casting process is complete.

2. The online identification method for stopper nozzle blockage in continuous casting process as described in claim 1, characterized in that: Step 200 also includes: based on the measured value p of the stopper rod argon back pressure at each time point. i Get the time window t during this period n Average value of argon back pressure in the inner plug rod Step 300 also includes: adjusting the range Δp y The second threshold of the range Δp max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning will be issued.

3. The online identification method for stopper nozzle blockage in continuous casting process as described in claim 1 or 2, characterized in that, Step 300 also includes: The range Δp y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked.

4. The online identification method for stopper nozzle blockage in continuous casting process as described in claim 1, characterized in that, Each threshold satisfies at least one of the following conditions: The first threshold of the range Δp max1 5-10 kPa; Range second threshold Δp max2 10-20 kPa; The third threshold of the range Δp max3 10-30 kPa; The average first threshold Δp1 is 15-40 kPa; The average second threshold Δp2 is 40-200 kPa.

5. The online identification method for stopper nozzle blockage in continuous casting process as described in claim 1, characterized in that, Time window t n The value range is 60-240s.

6. An online identification system for stopper nozzle blockage in a continuous casting process, characterized in that, Including the following steps: The data acquisition module collects data in real time within a set time window t during the continuous casting process. n Measured value p of argon back pressure of stopper at each moment i ; The difference module is based on the measured value p of the argon back pressure of the stopper at each time step. i Get the time window t during this period n The range Δp between the maximum and minimum argon back pressure of the inner plug rod y ; The alarm module will measure the range Δp y The first threshold of the range Δp max1 Compare, if Δp y ≥Δp max1 If so, a primary warning will be issued.

7. The online identification system for stopper nozzle blockage in continuous casting process as described in claim 6, characterized in that: The difference module is also based on the measured value p of the stopper argon back pressure at each moment. i Get the time window t during this period n Average value of argon back pressure in the inner plug rod The alarm module will also compare the range with the set second range threshold Δp. max2 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the first threshold Δp1: if Δp y ≥Δp max2 ,and Then a medium-level warning will be issued.

8. The online identification system for stopper nozzle blockage in continuous casting process as described in claim 6 or 7, characterized in that, The alarm module will also include the range Δp y The third threshold of the range Δp max3 Compare the values ​​and average the argon back pressure of the stopper rod. Initial average value of argon back pressure with stopper rod The difference is compared with the average value and the second threshold Δp2: if Δp y ≥Δp max3 ,and Then an alarm will sound if the water outlet is blocked.

9. The online identification system for stopper nozzle blockage in continuous casting process as described in claim 6, characterized in that, Each threshold satisfies at least one of the following conditions: The first threshold of the range Δp max1 5-10 kPa; Range second threshold Δp max2 10-20 kPa; The third threshold of the range Δp max3 10-30 kPa; The average first threshold Δp1 is 15-40 kPa; The average second threshold Δp2 is 40-200 kPa.

Images