Simple method for measuring long nozzle insertion depth

Abstract

This invention discloses a simple method for measuring the insertion depth of a long nozzle, relating to the field of steel metallurgy. The steps are as follows: Repeatedly measure and record the molten steel depth corresponding to different weights of molten steel in the tundish after pouring molten steel from the ladle, and compile the data into a reference table; fix the long nozzle to the outlet and insert the bottom of the long nozzle into the tundish; calculate the required height from the top of the tundish to the bottom of the ladle; connect a measuring device to one side of the ladle, and measure the actual height from the top of the tundish to the bottom of the ladle; adjust the height of the ladle. This invention, by creating a reference table of molten steel weight and depth in the tundish, transforms the direct measurement of insertion depth into an indirect measurement of the required height between the bottom of the ladle and the top of the tundish, and compiles the measurement data into a reference table, making the measurement and adjustment of the long nozzle insertion depth simpler, more efficient, safer, and more accurate.

Description

Technical Field

[0001] This invention relates to the field of steel metallurgy technology, specifically to a simple method for measuring the insertion depth of a long nozzle. Background Technology

[0002] In the steel production process, factories need to solidify molten steel. Traditional ingot casting exposes the molten steel to air, leading to severe oxidation and low-quality finished products. Therefore, factories now mostly use continuous casting, also known as tundish casting. Continuous casting guides the molten steel through a long nozzle between the ladle and the tundish, protecting it from secondary oxidation and preventing splashing. The ladle and tundish are both components of the continuous casting machine used to produce steel billets.

[0003] In continuous casting, each time the ladle is changed, the long nozzle connected to the previous ladle's outlet needs to be removed and fitted into the outlet of the next ladle. Then, it is inserted below the molten steel surface in the tundish for initial casting. If the long nozzle is inserted too deeply, inclusions such as guide sand will not easily float to the surface during initial casting and are easily drawn into the casting zone and into the crystallizer, causing inclusions in the transfer billet and potentially leading to ladle sputtering, which is quite dangerous. If the insertion depth is too shallow, fluctuations in the molten steel surface during initial casting can damage the protective casting layer, causing secondary oxidation and contamination of the molten steel. In short, both excessively deep and shallow insertion of the long nozzle into the tundish affect the quality of the finished billet. Therefore, it is necessary to measure the insertion depth of the long nozzle.

[0004] The patent specification with publication number CN213614121U discloses a simple device for measuring the insertion depth of a long nozzle. It includes a nozzle clamping ring, a control rod, and a measuring rod. The front end of the control rod is connected to the nozzle clamping ring, and the measuring rod is vertically fixed to the control rod. The measuring rod is engraved with scale. This technical solution has shortcomings: In actual use, molten steel is injected into the same tundish in batches at intervals using different ladles. Therefore, the molten steel level in the tundish is constantly changing. When using this device, the reference surface for measuring the insertion depth is the top surface of the tundish. However, due to the constantly changing distance between the molten steel level in the tundish and the top surface, the measurement data using the top surface as the reference surface is inaccurate. In other words, this solution cannot maintain dynamic stability in the insertion depth of the long nozzle when the molten steel level in the tundish changes. Summary of the Invention

[0005] The purpose of this invention is to provide a simple method for measuring the insertion depth of a long nozzle. The technical problem to be solved is as follows: Existing technical solutions cannot maintain dynamic stability of the insertion depth of a long nozzle when the molten steel level changes in the tundish.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A simple method for measuring the insertion depth of a long nozzle, used to measure the insertion depth of the long nozzle connecting the ladle and the tundish within the tundish where molten steel is being poured, is provided. The specific steps are as follows:

[0008] Step S10: Repeatedly measure and record the molten steel depth corresponding to different weights of molten steel in the tundish after the ladle pours molten steel into the tundish, and compile the data into a comparison table;

[0009] Step S20: Securely connect the long water inlet to the drain outlet, and insert the bottom of the long water inlet into the intermediate package;

[0010] Step S30: Determine the depth of molten steel in the tundish according to the reference table, and calculate the required height from the top of the tundish to the bottom of the ladle based on this depth.

[0011] Step S40: Connect a measuring device to one side of the ladle and measure the actual height of the top of the intermediate ladle from the bottom surface of the ladle.

[0012] Step S50: Adjust the height of the ladle.

[0013] As a further aspect of the present invention: the tundish includes a ladle body for loading molten steel, a ladle cover is provided at the top of the ladle body, the bottom of the long nozzle extends from the ladle cover into the interior of the ladle body, and a cavity is provided between the molten steel surface inside the ladle body and the bottom surface of the ladle cover.

[0014] As a further aspect of the present invention, the specific implementation of creating the comparison table in step S10 is as follows:

[0015] After molten steel is poured into the tundish, the weight of the molten steel is recorded according to the weight display instrument of the continuous casting machine. A high-temperature resistant tool is inserted into the tundish to measure the depth of the molten steel at that weight and the measurement is recorded. The measurement is repeated and the molten steel depth corresponding to different weights is statistically analyzed and a comparison table is made.

[0016] As a further embodiment of the present invention: the specific implementation of calculating the required height from the top of the tundish to the bottom of the ladle in step S30 is as follows:

[0017] Step S31: Based on the weight of the molten steel in the tundish displayed by the continuous casting machine, refer to the reference table to determine the depth of the molten steel in the tundish;

[0018] Step S32: Subtract the real-time molten steel depth from the existing depth data inside the tundish to obtain the cavity height;

[0019] Step S33: Calculate the length of the long nozzle located below the top of the intermediate package by adding the cavity height from step S32, the required insertion depth of the long nozzle, and the package cover height. Then, subtract this length from the fixed length of the long nozzle to obtain the required height.

[0020] As a further aspect of the present invention, the specific implementation of adjusting the ladle height in step S50 is as follows:

[0021] The difference between the actual height measured in step S40 and the required height calculated in step S30 is calculated, and the continuous casting machine adjusts the ladle height accordingly to match this difference.

[0022] The beneficial effects of this invention are:

[0023] In this invention, a weight-depth comparison table of molten steel in the tundish is generated by repeatedly measuring and recording the molten steel weight and corresponding molten steel depth in the tundish, which facilitates staff to quickly look up the molten steel depth in the tundish.

[0024] In this invention, the real-time depth of molten steel in the tundish is obtained by referring to a table. Combined with the predetermined depth of the long nozzle insertion, and the length attribute values ​​of the long nozzle and the tundish itself, the required height between the top of the tundish and the bottom of the ladle corresponding to the safe insertion depth is calculated. This avoids the danger of directly inserting the long nozzle and then measuring the depth. It transforms the direct measurement of the insertion depth into an indirect measurement of the required height between the bottom of the ladle and the top of the tundish, making the measurement process safer.

[0025] In this invention, the actual height between the bottom surface of the ladle and the top of the tundish is measured by measuring the measuring device. The difference between the required height and the actual height can be calculated to obtain the direction and height of the ladle to be adjusted, making the insertion process of the long nozzle to the predetermined depth more accurate and convenient.

[0026] In this invention, by recording the required heights corresponding to different weights of molten steel and compiling them into a reference table, staff only need to measure the actual height between the bottom of the ladle and the top of the tundish during the adjustment process and consult the reference table to quickly and adaptively adjust the ladle height, making the adjustment process more efficient. Attached Figure Description

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] Figure 1 This is a flowchart of the present invention;

[0029] Figure 2 This is a flowchart illustrating the process of calculating the required height from the top of the tundish to the bottom of the ladle according to the present invention.

[0030] Figure 3This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 4 This is the present invention. Figure 3 Enlarged view of point A in the middle.

[0032] In the diagram: 1. Steel ladle; 2. Drain outlet; 3. Long outlet; 4. Tundish; 41. Ladle body; 42. Ladle cover; 43. Cavity; 5. Measuring piece. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figures 1 to 4 As shown, a simplified method for measuring the insertion depth of a long nozzle is described. In continuous casting, both the ladle 1 and the tundish 4 are components of the continuous casting machine. During continuous casting, the machine sequentially pours molten steel from different ladles 1 into the same tundish 4. The height of the ladle 1 can be adjusted during ladle 1 replacement. Simultaneously, the continuous casting machine is equipped with a real-time display instrument for the weight of the molten steel in the tundish 4. Furthermore, the height h1 inside the tundish 4 is a property value. All of this information is prior art.

[0035] Step S10: This step is used to compile a reference table showing the weight of molten steel in tundish 4 corresponding to its depth. During the billet production process, the continuous casting machine needs to continuously inject molten steel from different ladles 1 into the same tundish 4, causing the weight of molten steel in tundish 4 to continuously increase. When creating the reference table, before each injection of molten steel from ladle 1, the weight of molten steel in tundish 4 is observed. Then, a high-temperature resistant tool is inserted into tundish 4 and removed. The depth of molten steel at that weight is calculated by measuring the length of the molten steel adhesion layer. The weight and depth of molten steel are recorded. As molten steel is continuously injected into tundish 4, the database is expanded, and the reference table is finally created. Preferably, the high-temperature resistant tool is an L-shaped high-temperature resistant steel rod with an outer aluminum-zirconium-carbon composite layer. Its length is greater than the overall height of tundish 4. The operator holds the steel rod horizontally at the end covered with heat-insulating adhesive and inserts and removes it into tundish 4 to assist in the creation of the reference table.

[0036] Preferably, the following table is a comparison table of molten steel weight and molten steel depth.

[0037]

[0038]

[0039]

[0040] Step S20: This step connects the ladle 1, to be filled with molten steel, to the long nozzle 3 and inserts the long nozzle 3 into the tundish 4. During the continuous filling of molten steel into the tundish 4, the long nozzle 3, which is already filled with molten steel in the ladle 1, needs to be removed from the bottom outlet 2 of the ladle 1. Once the new ladle 1, to be filled with molten steel, is suspended above the tundish 4, one end of the removed long nozzle 3 is inserted into the tundish 4, and the other end is connected to the bottom outlet 2 of the new ladle 1, thus preparing for the filling of molten steel.

[0041] Step S30 is used to calculate the required height between the bottom surface of the ladle 1 and the top surface of the tundish 4 when the long nozzle 3 is inserted into the tundish 4 to a predetermined depth. Since the molten steel is located inside the tundish 4 when it is injected, and the insertion depth inside the tundish 4 is not measurable by the naked eye, directly measuring the insertion depth is not only inaccurate but also dangerous. Therefore, an indirect measurement method is required. On the other hand, in order to ensure that the quality of the billet is not affected when the long nozzle 3 is injected with molten steel, its insertion depth below the molten steel surface in the tundish 4 needs to be between 150 mm and 200 mm. In addition, a ladle cover 42 is provided at the top of the tundish 4, and the main body for holding the molten steel is the ladle body 41. The space between the upper surface of the molten steel inside the ladle body 41 and the bottom surface of the ladle cover 42 is the cavity 43.

[0042] The specific steps for calculating the required height are as follows: Before injecting molten steel, observe the weight inside the tundish 4 and refer to the reference table to obtain the depth h2 of the molten steel inside the tundish 4. The total height inside the tundish 4 is h1. Then, the height of the cavity 43 inside the tundish 4 is h1 minus h2 and recorded as h3. The thickness of the ladle cover 42 is recorded as h4. The insertion depth of the long nozzle 3 into the molten steel is recorded as h5. Then, the sum of h3, h4 and h5, L1, is the total length of the long nozzle 3 after it is inserted into the molten steel at the predetermined depth and located below the top of the tundish 4. The length of the long nozzle 3 is recorded as L0. Then, L0 minus L1, L2, is the required height value between the top of the tundish 4 and the bottom surface of the ladle 1.

[0043] Step S40: This step is used to measure the actual height between the top of the tundish 4 and the bottom surface of the ladle 1. To facilitate this measurement, a measuring component 5 is installed on one side of the ladle 1. The measuring component 5 is connected to the ladle 1 by binding, and includes, but is not limited to, a steel measuring rod and a steel ruler. During the measurement process, the measuring component 5 is removed from one side of the ladle 1, and the operator measures the actual height H between the top of the tundish 4 and the bottom surface of the ladle 1.

[0044] Step S50 is used to adjust the height of ladle 1 so that the long nozzle 3 is inserted into the tundish 4 to a predetermined depth. The required insertion depth is calculated as L2 in step S30, and the actual height H between the top of the tundish 4 and the bottom of ladle 1 is measured in step S40. The difference L between L2 and H is the vertical height that ladle 1 needs to be adjusted. After calculating the value of L, the operator adjusts the height of ladle 1 by the corresponding value through the continuous casting machine; if the result is positive, it is adjusted downwards, and if the result is negative, it is adjusted upwards.

[0045] Example

[0046] A measuring rod is attached to the edge of the ladle 1. This measuring rod is used to measure the distance between the lower surface of the ladle 1 and the ladle cover 42 each time the pouring begins.

[0047] Before opening the ladle 1 to inject molten steel, the long nozzle 3 is inserted into the molten steel in the tundish 4. The weight of the molten steel in the tundish 4 is 42.6 tons. According to the reference table, the depth of the molten steel in the tundish 4 is 800 mm and the overall height of the tundish 4 is 1260 mm. At this time, the height of the cavity 43 is 460 mm. Meanwhile, the thickness of the ladle cover 42 is 120 mm. The insertion depth of the long nozzle 3 is 200 mm. Therefore, the length of the long nozzle 3 below the top of the tundish 4 is calculated to be 780 mm.

[0048] The length of the long nozzle 3 is 1500 mm. The distance between the top of the ladle cover 42 of the intermediate ladle 4 and the bottom surface of the ladle 1 is the required height, which is calculated to be 720 mm. Remove the measuring rod bound to the edge of the ladle 1, measure the actual height between the top of the ladle cover 42 and the bottom surface of the ladle 1, calculate the difference, and control the ladle 1 to move the difference vertically to achieve the accurate depth insertion of the long nozzle 3.

[0049] It should be noted that as the amount of molten steel injected into the tundish 4 increases continuously with the continuous injection of molten steel into the ladle 1, after multiple calculations of the required height corresponding to different tonnages of molten steel, the required height corresponding to the weight of molten steel in the tundish 4 can be recorded and statistically analyzed. With sufficient data support, a reference table of the required height corresponding to the weight of molten steel in the tundish 4 can be created. During the adjustment process, the staff only needs to use the measuring piece 5 to measure the actual height between the ladle cover 42 and the bottom surface of the ladle 1 and refer to the reference table to calculate the difference to make adaptive adjustments to the height of the ladle 1. This is simple, convenient, safe, and accurate.

[0050] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A simplified method for measuring the insertion depth of a long nozzle (3) connecting a ladle (1) and a tundish (4) within the tundish (4) into which molten steel is injected, characterized in that, The specific steps are as follows: Step S10: Repeatedly measure and record the molten steel depth corresponding to different molten steel weights in the tundish (4) after the ladle (1) injects molten steel into the tundish (4), and compile the data into a comparison table; The specific implementation method for creating the comparison table in step S10 is as follows: After molten steel is poured into the tundish (4), the weight of the molten steel is recorded according to the weight display instrument of the continuous casting machine. A high-temperature resistant tool is inserted into the tundish (4) to measure the depth of the molten steel under that weight and the result is recorded. The measurement is repeated and the molten steel depth corresponding to different weights is statistically analyzed and a comparison table is made. Step S20: Fix the long water inlet (3) to the drain outlet (2) and insert the bottom of the long water inlet (3) into the intermediate package (4); Step S30: Determine the depth of molten steel in the tundish (4) according to the reference table, and calculate the required height of the top of the tundish (4) from the bottom of the ladle (1) based on this molten steel depth; Step S40: Connect measuring piece (5) to one side of the ladle (1) and measure the actual height of the top of the intermediate ladle (4) from the bottom of the ladle (1) by measuring piece (5); Step S50: Adjust the height of the ladle (1).

2. The simplified method for measuring the insertion depth of a long nozzle according to claim 1, characterized in that, The intermediate ladle (4) includes a ladle body (41) for loading molten steel. A ladle cover (42) is provided at the top of the ladle body (41). The bottom of the long nozzle (3) extends from the ladle cover (42) into the interior of the ladle body (41). A cavity (43) is provided between the molten steel surface inside the ladle body (41) and the bottom surface of the ladle cover (42).

3. A simplified method for measuring the insertion depth of a long nozzle according to claim 2, characterized in that, The specific implementation method for calculating the required height of the top of the intermediate ladle (4) from the bottom of the ladle (1) in step S30 is as follows: Step S31: Based on the weight of molten steel in the tundish (4) displayed by the continuous casting machine, refer to the reference table to determine the depth of molten steel in the tundish (4); Step S32: Subtract the real-time molten steel depth in step S31 from the existing depth data inside the tundish (4) to obtain the height of the cavity (43); Step S33: The length of the long nozzle (3) located below the top of the intermediate bag (4) is calculated by adding the required insertion depth of the long nozzle (3) and the height of the bag cover (42) to the height of the cavity (43) in step S32. Then, the required height is obtained by subtracting the length of the fixed-length long nozzle (3).

4. A simplified method for measuring the insertion depth of a long nozzle according to claim 1, characterized in that, The specific implementation method for adjusting the height of the ladle (1) in step S50 is as follows: The difference between the actual height measured in step S40 and the required height calculated in step S30 is calculated, and the continuous casting machine adjusts the ladle (1) to the appropriate height to match the difference.

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