KR100973919B1 - Apparatus for preventing slag from flowing out of a converter - Google Patents

Abstract

It provides a slag outflow prevention device when the converter goes out using the gas blowing lead with an extended service life.

The slag outflow prevention device when the converter is going out and out, the slag outflow prevention device including the gas blowing lead disposed around the exit port of the converter to generate gas bubbling to prevent the slag outflow when the converter is going out, the gas injection The lead is provided with: a first gas blowing lead provided to blow in gas upon initial tapping of the converter; And a second gas blowing edge provided to increase the number of times of use of the converter and to continue to blow gas with damage to the first gas blowing edge.

According to the present invention, the entire service life of the gas blown smoke can be extended to the converter service life, thereby enabling stable bubbling at all times during the converter's descent and thus improving the effect of effectively preventing the outflow of slag during the descent of the converter. .

Converter, refining, molten steel, converter tapping, slag, slag spill prevention device

Description

Slag outflow prevention device in the case of going out and out of the converter {APPARATUS FOR PREVENTING SLAG FROM FLOWING OUT OF A CONVERTER}

1 is a schematic diagram showing an outflow state of slag when the converter descends

Figure 2 is a schematic diagram showing a method of using a gas blown smoke in order to prevent the outflow of slag when the conventional converter tapping

3 is a schematic perspective view showing various embodiments with a conventional gas blowing lead

4 is a view illustrating a gas blowing edge having an extended service life used in the present invention,

(a) is a structural diagram showing the first gas blowing edge having the shortest life instead of the fastest gas blowing start time

(b) is a structural diagram showing a second gas blowing edge having a medium gas start starting period and a middle life

(c) is a structural diagram showing a third gas blowing edge having the latest gas injection start period and the longest lifespan.

FIG. 5 illustrates the 1-3th gas blowing edge and the erosion state of FIG. 4,

(a) is a schematic diagram showing the erosion state with the first gas blowing lead                 

(b) is a schematic diagram showing the erosion state with the second gas blowing lead

(c) is a schematic diagram showing the erosion state with the third gas blowing lead

Fig. 6 is a plan view showing the converter outlet side showing the arrangement state of the first to third gas blowing edges of the present invention;

Explanation of symbols on the main parts of the drawings

10 .... converter 12 .... exit

20 .... molten steel 22 .... slag

40 .... with conventional gas blown smoke 100 .... with gas blown smoke of the present invention

110 .... smoke and body 120 .... gas blowing hole

130 .... Gas blowing pipe A, B .... Gas blowing hole not formed

Y .... Lower area of converter exit A .... Lead body body erosion line

B. Frail and body erosion line

The present invention relates to a device for preventing the slag is leaked through the converter exit when the molten steel tapping the converter, more specifically, the vortex (voltex) (hereinafter referred to as `` Vortex '') that causes the outflow of slag during the converter tapping Can extend the service life of the gas blown smoke that blows gas to the converter, providing continuous and stable bubbling at the converter exit when the converter is going out. The present invention relates to a slag outflow prevention device at the time of going out and out of the converter to effectively suppress the outflow of slag during the outgoing of the converter.

The molten iron, which has undergone preliminary treatment, that is, delineation and dehydration, is charged to the converter and subjected to refining treatment (Oxygen Blowing) along with input of main raw materials such as scrap iron and cold wire and quick raw materials such as quicklime, dolomite and iron ore. The treatment takes about 17 minutes.

Then, after the refining process, as shown in Figure 1, in the state in which the converter 10 is tilted at a predetermined angle, the molten steel 20 in the converter inside the converter through the converter outlet 12 to receive the molten steel The ladle 30 is pulled out within about 5 minutes, and the oxidative slag 22 having a low specific gravity is suspended on the molten steel 20.

By the way, when the molten steel 20 is initially tapped during the molten steel tapping operation of the converter, when the molten steel is finished tapping, that is, when the slag 22 is adjacent to the converter tapping hole 12 side, Vortex (v) is formed during the tapping in the sphere (12) portion, such a vortex (v) is not only the molten steel 20 but also a considerable amount of oxidative slag 22 through the converter tapping hole 12 To 30 together.

That is, as shown in Figure 1, the main cause of the slag 22 is leaked when the converter is going out due to the funnel-shaped vortex (v) continuously generated in the upper portion of the tapping hole 12, such a vortex Since the molten steel 20 which is in contact with the lead surface of the converter outlet 12 has a slow falling speed by resistance, the molten steel 20 that does not contact the lead surface of the tap hole 12 has a fast falling speed, As the phenomenon occurs in the central portion of the funnel appearance in appearance, but the slag 22 is continuously introduced into the center is discharged from the converter outlet (12).

However, when such a considerable amount of oxidative slag 22 is discharged during the converter tapping, it adversely affects the cleanliness of the steel, makes it difficult to control the slag composition in the secondary refining process after tapping, and also deoxidizes the oxidizing slag. In addition, since a large amount of carbon dioxide should be added, not only the cost rises but also the problem of deteriorating the overall refining operation.

That is, the slag 22 introduced into the steel ladle 30 contaminates the molten steel 20, oxidizes the molten steel, and generates various inclusions, resulting in economic losses due to the occurrence of additional processes due to deterioration in the post-treatment process. To come.

On the other hand, although not shown in the drawing, as a method for solving other problems in the outflow of the slag is to use a slag check ball (Slag Check Ball), which is a large specific gravity compared to the slag, Since the specific gravity is smaller than that of molten steel, the slag check ball is always present between molten steel and slag when molten steel and slag are present together, and the specific gravity difference between the molten steel and slag is almost completed. The slag check ball, which is suspended in the block, blocks the converter outlet immediately before the outlet of the slag, and separates the molten steel and the slag, thereby preventing the outflow of the slag.

However, in the case of using the slag check ball as described above, since the molten steel blocks the converter entrance with the slag check ball when the tapping is almost completed, it is difficult to completely block the outflow of the slag, and from the end of the actual tapping period. Since the slag check ball floats on the molten steel until the beginning, as described above, the slag check ball is also rotated by the vortex, which is a substantial cause of the outflow of the slag, and there is almost no suppression effect of the vortex.

Therefore, the vortex generated at the converter exit during the course of the converter can not be blocked by the slag check ball input method as described above, it is not possible to effectively prevent the slag outflow by the vortex.

On the other hand, Korean Patent No. 10-0356169 discloses a technique for solving the problem of leakage of slag during the falling down of the converter by the vortex (v), which is shown in FIG.

That is, as shown in FIG. 2, the gas blowing lead 40 is provided at a position approximately 3-5 times the diameter D of the tapping hole from the tapping hole 12 of the converter 10 and the inert gas at the time of tapping the converter. For example, by blowing nitrogen or argon gas, bubbles (BUBBLE) 50 by the gas blown in the vicinity of the tap hole are generated to suppress the vortex.

On the other hand, Figure 3 shows the various use state of the gas blowing lead 40, the various types of gas blowing holes 44a, 44b, 44c (44d) 44e in the lead body 42 In addition, the gas intake pipe 46 (FIG. 2) is connected to the lower part of the body 42 to be integrally constructed with the converter.                         

However, in such a slag outflow method through the gas blowing lead 40, the gas temperature blown is at room temperature, whereas the gas blowing lead 40 is a high temperature, so if the gas at room temperature is blown with the hot blowing gas ( In 40), thermal shock occurs due to a rapid temperature change. This is because the furnace temperature is 1600 ° C. or higher and the gas temperature is room temperature. Thus, the gas blowing lead 40 easily becomes a thermal shock due to thermal stress caused by rapid heat and quenching. The problem of damage is the occurrence.

Therefore, in general, the converter 20 has a service life of about 500-1000 times based on the number of times of use, and considering that the lifetime of the converter lead (fire retardant wire) is 3,500-8,000 times, the gas blown smoke edge 40 is Easily damaged by thermal shock, for example, because of the erosion damage to the molten steel 20 in the cracks generated from the blown smoke and the body 42 due to the thermal shock, its service life is only 250-350 times based on the number of converters.

As a result, the gas blowing lead 40 used in order to prevent the slag outflow of the conventional converter actually has to be applied only to the initial use period of the converter, and if it is determined that the damage is severe, the blowing of gas in consideration of the inflow of the gas blowing pipe of the molten steel Stopped.

In addition, since only one gas blowing edge 40 is applied to the converter 20, the amount of gas taken into the converter molten steel is not constant, and if the gas blowing pressure is unstable in use, the stainless pipe is a gas blowing pipe 46. There was a problem that (STS PIPE) was immediately blocked by molten steel or slag, so that the molten steel particles of gas were impossible.

The present invention has been made in order to improve the various problems as described above, the object of the present invention is that the service life of the converter with the total service life of the gas blowing lead to blow the gas to block the vortex, which is the source of slag when the converter is going out It can be extended to the front and back, and by providing continuous and stable bubbling at the converter entrance, it effectively suppresses the vortex at the converter entrance to prevent the slag outflow during the conversion. It is to provide a slag outflow prevention device.

As a technical configuration for achieving the above object, the present invention, gas bubbling to prevent slag outflow during the transition of the converter to prevent slag outflow during the transition to the converter including a gas blowing edge disposed around the exit of the converter. In the device,
The gas blowing lead includes: a first gas blowing lead provided to blow gas during initial tapping of the converter; And,
A second gas blowing lead provided with an increased number of uses of the converter and continuing to blow gas with damage to the first gas blowing lead;
It provides a slag leak prevention device when the converter is configured to include.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, the same configuration as the prior art is denoted by the same reference numerals.

First, FIG. 3 illustrates a conventional gas blowing lead 40, and as shown in FIG. 3A, one gas blowing hole 44a is formed in the gas blowing lead and the body 42, and in FIG. 3B. As shown in FIG. 3C, a gas blowing hole 44c having a double pipe form is formed in the gas blowing lead and the body 42 as shown in FIG. 3C. As shown in FIG. 3D, a gas blowing hole 44d having a plurality of slit (SLIT) shapes is formed in the gas blowing lead and the body 42, and finally, as shown in FIG. 3E, the gas blowing lead and the body ( A form in which a multi-hole duplex gas inlet 44e is formed in 42 is used.

However, the various types of gas blowing holes 44a to 44e used in the conventional gas blowing lead 40 are integrally formed in the longitudinal direction of the body 42 of the gas blowing lead 40. The start point of tilting the converter 10 to pull the molten steel 20 to the receiving ladles 30 coincides with the start point of gas injection.

Therefore, as described above, since the thermal shock applied to the gas blowing lead 40 while the gas at room temperature is supplied to the hot lead, the gas blowing edge 40 shown in FIG. Regardless of the shape of the gas blowing holes 44, cracks are generated due to deterioration from the start of use, so that the entire service life of the converter cannot be used, and bubbling through gas injection only occurs during the initial period of the converter to suppress the outflow of slag. There is only a suggestive effect.

Meanwhile, FIG. 4 illustrates various types of gas blowing edges 100a, 100b, and 100c of the apparatus for preventing slag outflow when the present inventors descend the converter, and the gas blowing edge 100a of FIG. 4a is shown in FIG. Similar to the conventional gas blown edges 40 shown, the gas blowing holes 120a formed in the body 110 are integrally formed in the longitudinal direction, which will be referred to as a first gas blown edge of the present invention. .

By the way, there are shown other gas blowing edges (100b, 100c) used in the slag outflow prevention device of the present invention shown in Figures 4b and 4c, the characteristics of these gas blowing edges (100b) (100c) is substantially The gas blowing holes 120b and 120c which enable gas injection and at the same time affect the damage of the duct are not formed integrally in the longitudinal direction of the body 110 but are formed only with a specific length. It is called a 2nd and 3rd gas blowing lead.

Therefore, since the gas blowing holes 120b and 120c are not integrally formed up to the front end of the body 110, the second and third gas blowing edges 100b and 100c are simultaneously blown with the gas at the time of the first tapping. Gas blowing holes 120b and 120c are exposed to molten steel only after the hole unformed portions A and B of a predetermined length in which the blowing holes are not formed are damaged and eroded by molten steel. This will be possible.

That is, the conventional gas blown edge 40 as shown in FIG. 3 or the first gas blown edge 100a of the present invention shown in FIG. 4A is a molten steel or slag gas blown pipe 46 when gas is not blown at the point of use. However, the blockage phenomenon occurs in the second and third gas blowing leads 100b and 100c of the present invention shown in FIGS. 4b and 4c, but the gas blowing holes 120b and 120c are different from each other. It is formed from the middle of the lead body 110 in width, so that the gas is supplied to the inside of the converter even if the gas is supplied to the gas blowing holes 120b and 102c without the portion of the lead body 110 (A and B in FIG. 4) being eroded. It cannot be blown, so no gas bubbling is possible, and molten steel or slag cannot enter the inside of the gas blown pipe 130, so that the second and third gas blowing edges 100b and 100c of the present invention are gas bubbling. The start delay is intentionally made gas blown smoke.

Therefore, as a result, since the third gas blowing edge 100c of FIG. 4C and the second gas blowing edge 100b of FIG. 4B are slower to start bubbling through gas blowing under the same material, size, and use conditions, In the present invention, when the first to third gas blowing edges and 100a, 100b, and 100c are used in at least two or all of them, the converter is used for the entire period of use as compared with the case of using only one gas blowing lead 40 in the related art. By bubbling through the gas blowing it is possible to continuously block the slag outflow by the vortex (v).

That is, in the present invention, by using a plurality of gas blowing lead 100 and the gas starting start point, the bubbling at the converter outlet 12 through the gas blowing through the entire use period of the converter, so that the converter It is to be able to stably prevent the leakage of slag at the time of tapping.

Next, FIG. 5 illustrates the erosion degree due to thermal shocks of the first to third gas blowing edges and the 100a, 100b, and 100c used in the apparatus of the present invention described above.

That is, as shown in FIG. 5A, since the gas blowing hole 120a is integrally formed through the body 110 in the longitudinal direction of the body 110, the first gas blowing lead 100a receives gas from the beginning of the converter tapping. In this case, as the thermal shock is rapidly applied, the erosion by the molten steel occurs as shown in FIG. 5A.

However, as compared with the first gas blowing lead 100a, the second gas blowing lead 100b in FIG. 5B has no gas injection hole 120b formed therein. When the 120a is eroded a little less in the same converter use period than the integrally formed portion ('b' of FIG. 5b), and then eroded to the gas blowing hole 120b, the first gas blowing lead 100a and 2 The gas is blown in through the gas blowing lead 100b.

Therefore, when the first gas blowing edge 100a begins to erode after the initial period of the entire molten steel use period of the converter, the second gas blowing edge 100b blows gas and simultaneously the first and second gas blowing edges 100a. Blowing gas is generated in the bubble (100b) to generate bubbling.

Next, as illustrated in FIG. 5C, when the use period of the converter is increased and the first gas blowing edge 100a is eroded by various erosion lines ('na' lines), it is difficult to blow gas. FIGS. 5B and FIG. As shown in FIG. 5C, when the erosion reaches the gas blowing hole 120c through the second gas blowing lead 100b that has advanced to the 'na' line and the two erosion lines 'ga', the second gas blowing lead 100b In addition, the gas is blown up to the third gas blowing edge 100c and the vortex v on the converter outlet 12 side is suppressed while generating the bubbling.

Therefore, in the slag outflow prevention device at the time of moving the converter according to the present invention, the gas is blown through the first gas blowing lead 100a only in the initial use of the converter, but if the first gas blowing lead 100a is eroded Since the gas is continuously blown from the third gas blowing edge 100c via the second gas blowing edge 100b to generate bubbling, the slag outflow can be stably suppressed at all times when the converter is pulled out.

As a result, in consideration of the total service life of the converter tapping work, the second or / and third gas blowing edges 100b and 100c having different gas bubbling start timings are different than when only the first gas blowing edge and 100a are used alone. When used together, the gas bubbling that substantially suppresses the vortex (v) at the converter exit is generated stably throughout the converter's use period, so that the slag outflow can be prevented constantly and constantly.

On the other hand, Figure 6 shows the installation state of the first, second, or first to third gas blowing edges 100a, 100b, 100c used in the slag outflow prevention device of the present invention.

That is, as shown in FIG. 6, the flow of slag on the basis of the converter exit hole 12 is more lower than the upper region X based on the converter exit hole 12. As shown in Figure 1, which forms a wide round dalgal, the upper region relative to the converter outlet 12 when the converter 10 is tilted and the molten steel 20 is pulled through the tapping hole 12 (X) is a portion where the converter tail is inclined rapidly, so the amount of slag is small, and the lower region Y on the opposite side has a large amount of slag.

6, the first to third gas blowing edges 100a, 100b, and 100c of the present invention have a radius of about 3-5 times the diameter of the tap hole based on the converter tap hole 12. It is preferable to be spaced apart at intervals of 30 degrees to the left and right, based on the domestic patent 10-0356169 described in the prior art discloses that the bubbling effect is the best at the separation distance.                     

In addition, since the lower area Y has a large amount of slag on the basis of the converter outlet 12, the flow 22a of the slag 22 becomes large and rapid in this area, so that the vortex substantially causing the slag outflow ( v) is also more affected by the lower region, by placing the gas blowing lead 100 of the present invention in this region to block the flow or inflow of the converter outlet side of the slag.

Meanwhile, although schematically illustrated in FIG. 6, in the present invention, the first and second gas blowing edges 100a and 100b are installed and used at points a and b, so that the gas blowing can be continuously performed during the converter period. Alternatively, it may be possible to arrange the 1-3 gas blowing edges 100a, 100b, and 100c at a predetermined radius with respect to the converter outlet 12 at three points of a, b, and c, respectively.

In addition, although not shown in the drawing, it may be possible to use a plurality of gas blowing edges, for example, the first gas blowing edge 100a is arranged in a semi-circular shape along a radius with respect to the converter outlet 12. It may also be possible to arrange the second gas blowing edges 100b in a semicircular shape, and then to arrange the third gas blowing edges 100c in a semicircular shape, and then, of course, at this time, The arrangement section may be preferably 3-5 times the diameter of the converter tap hole 12.

(Example)

Hereinafter, preferred embodiments will be described in order to help the understanding of the present invention, but the present invention is not limited thereto.

First, the actual model of the converter was reduced and the water model test was conducted. At this time, the simulation of molten steel used water and the simulation of slag used oil (specific gravity 0.5 ~ 06g / cm3). To this end, 22 liters of water were used and 1 liter of oil was used.

At this time, the flow rate of the nitrogen gas blown was set to 2-2.1 liters / min in accordance with the similar conditions for the converter, and the gas bubbling point was arranged at two points a, b, c as shown in Figure 6, a, Point b is placed at an angle point of 30 degrees from the exit center line and at a right angle position of point c so that the first to third gas blowing edges 100a, 100b and 100c are only in the lower area Y of the exit port. ) At least two.

And the result of having tested the gas using argon gas which is an inert gas is shown in following Table 1.

Oil Spill by Gas Blowing Lead and Blowing Point division point a
Gas blown smoke point c
Gas blown smoke point b
Gas blown smoke Oil spill
(ml) Conventional Example 1 Not taken Not taken Not taken 273-285 Conventional Example 2 Blown Not taken Not taken 195-215 Conventional Example 3 Not taken Blown Not taken 190-201 Conventional Example 4 Not taken Not taken Blown 210-220 Inventory 1 Blown Blown Not taken 149-158 Inventory 2 Blown Blown Blown 128-135 Inventory 3 Not taken Blown Blown 161-165

That is, as can be seen in Table 1 and Figure 6, in the case of the conventional example 1 which does not use the gas blowing edge at all, the oil outflow amount in place of the slag when tapping in the example was 273-285ml, a, b, c points In each of the conventional examples 2, 3, 4, which are used by arranging the gas blowing lead at, it can be seen that the oil outflow amount is reduced to about 70-77% level compared with the case where the gas blowing lead is not used.

However, in the case of the present invention, as in the case of the invention examples 1 and 3, when the gas is blown at the a or b point and the c point, respectively, gas bubbling occurs, the oil leakage amount is 55 as compared to the conventional example 1 at the time of no gas injection. %, 58%, and when the gas is blown at the a, c, b3 point as in Example 2, it can be seen that the oil outflow amount reduced to a maximum of 47%.

Therefore, when using at least two gas blowing edges as in the present invention, it can be seen that the oil outflow, that is, the slag outflow decreases, in particular, clogging or excess of the gas blown smoke generated when using one gas blowing edge. This problem is solved by the erosion which is impossible to collect gas, and finally, it maintains gas intake during the converter's use period, thereby providing stable bubbling around the converter's exit and effectively preventing slag outflow by vortex. .

As described above, according to the apparatus for preventing slag outflow at the time of tapping the converter using the gas blowing edge with an extended service life of the present inventor, the bubbling start time due to the gas blowing is used at least two or more gas blowing edges, so that the gas blowing edge due to thermal shock is used. As the damage period is adjusted, the overall service life with the gas blowing lead can be extended, so that the gas bubbling is generated and maintained stably with stable gas injection at the time of going to the converter, effectively blocking the vortex which is the main cause of the slag outflow. It provides an excellent effect of effectively preventing converter leakage.

Therefore, the gas blown smoke can be used until the converter is used, thereby stably blocking the outflow of the slag, thereby providing an effect of preventing various trouble factors such as molten steel contamination by the slag.

While the invention has been shown and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention as set forth in the claims below. I would like to know that those who have knowledge of this can easily know.

Claims (4)

In the apparatus for preventing slag outflow during the transition to the converter including a gas blowing edge that is disposed around the exit port 12 of the converter 10 to generate gas bubbling to prevent the slag outflow during the transition to the converter. The gas blowing lead comprises: a first gas blowing lead (100a) provided to blow in gas during initial tapping of the converter; And, A second gas blowing lead 100b provided to increase the number of times of use of the converter and to continue to blow gas with damage to the first gas blowing lead; Slag leakage prevention device when the converter is characterized in that it comprises a configuration. 2. The gas blowing lead of claim 1, further comprising a third gas blowing lead (100c) provided to further increase the number of uses of the converter and to continue to blow gas with damage to the second gas blowing lead. Slag leakage prevention device when the converter is characterized in that the falling. The gas injection hole 120a is integrally formed in the body 110 so that the first gas blowing lead and the gas can be blown at the initial stage of the converter, and the second and third gas blowing leads 100b are formed. ) 100c is a hole unformed portion (A) (B) in which gas injection holes 120b and 120c are not formed at different widths so as to continuously blow gas upon damage with the first and second gas blowing edges. Slag outflow prevention device when the converter is characterized in that it is configured to suppress the slag outflow by providing a stable bubbling up to the service life of the converter while blowing the gas in sequence. According to claim 2, wherein the gas blown edges are arranged in a circular shape at least three to five times the diameter of the converter outlet to the lower region of the converter outlet 12, or at least two or more within the point Slag outflow prevention device during the conversion of the converter characterized in that each arranged in a row in a circle.

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