KR20140002830A - Apparatus for refining molten steel - Google Patents

Abstract

The present invention relates to a refining apparatus of molten steels and provides a refining apparatus of molten steels characterized by a layout structure of a bottom-blown nozzle capable of controlling contents of a molten steel in a not yet decarburized steel. An embodiment of the present invention comprises a steelmaking furnace to accommodate a molten steel, and at least one pair of low-blown nozzles arranged oppositely in a point symmetry with reference to a center point of a bottom face of the steelmaking furnace and positioned on mutually opposite sides with reference to a reference axis as a diameter of the bottom face. In addition, a top-blown lancing for supplying gas from an upper part of the steelmaking furnace is included. Also, the pair of bottom-blown nozzles comprise a bottom-blown nozzle of a charging side positioned on the charging side with the reference axis as a center, and a bottom-blown nozzle of a steel tapping side positioned on the steel tapping side with the reference axis as a center. [Reference numerals] (AA) Loading side; (BB) Reference axis(Tilting axis); (CC) Bottom-blown nozzle; (DD) Steel-tapping side

Description

Apparatus for refining molten steel}

The present invention relates to a molten steel refining apparatus, and is a molten steel refining apparatus characterized by an arrangement structure of a low odor nozzle capable of controlling the content of molten steel in mithalated steel.

The process for producing ferro-manganese involves charging manganese ore and reducing agent cokes and slag forming agent into an electric furnace to reduce manganese ore in the form of oxide using carbon (C) of coke. It is prepared by making. The ferromanganese produced using coke in an electric furnace is obtained in the form of high carbon ferromanganese in which carbon (C) is saturated in a product due to coke as a reducing agent.

A problem in using the commonly used ferro manganese in the steelmaking process is the amount of carbon (C) and phosphorus (P) component contained in the ferro manganese. Carbon is the most important component in determining the properties of steel and, in particular, efforts to reduce the carbon concentration for the production of ultra low carbon high manganese steel. Therefore, in the case of using ferro-manganese, the carbon concentration in molten steel by ferroalloy should be taken into consideration, which may make it impossible to use ferro-manganese and control the carbon concentration of ferro-manganese.

In general, the decarburization process of ferro-manganese is charged with high-carbon ferro-manganese produced in an electric furnace into a decarburization furnace, and a high-speed oxygen gas is blown from the upper portion through a lance (hereinafter referred to as 'refreshing' ( ), Blowing oxygen or inert gas from the bottom of the decarburization furnace (hereinafter referred to as 'low'), or blowing oxygen or an inert gas from the sidewall of the decarburization furnace (hereinafter referred to as 'harvest') Iii) through the method.

In the decarburization furnace, the ferro-manganese in the molten state is agitated by the bubbling operation by the gas at the bottom to homogenize the components in the molten steel and promote the chemical reaction in the ferro-manganese or on the surface. Since ferromanganese has high oxygen affinity and high vapor pressure, the loss due to oxidation and evaporation during the decarburization process is very large. Therefore, it is important to select a proper blowing pattern and secure stirring ability to increase the error rate of ferromanganese and promote decarburization. In particular, when decarburization is carried out by the combined blow method using the upper and lower odors, the stirring by the low odor gas governs the stirring ability of the decarburization furnace. Do.

In the existing decarburization furnace, in order to reduce oxidation and evaporation losses due to high oxygen affinity and high vapor pressure between ferro manganese, a method of injecting oxygen into a low odor or a odor is used. As shown in FIG. 1, the existing decarburization furnace uniformly distributes the nozzles 12 for injecting oxygen to the bottom surface 11 of the decarburization furnace to uniformly supply oxygen to the ferro-manganese in the decarburization furnace. However, such a low odor arrangement causes the formation of stagnant regions due to interference between nozzles, thereby lowering the decarburization capacity of the decarburization furnace and the ferromanganese error rate. In the case of the existing low odor arrangement, the oxygen lances arranged on the charging side and the tapping side are placed on the lower side, and thus the nozzles or the refractory are damaged. This causes a problem in extending the life of the decarburization furnace and has a problem of causing an operation accident.

U.S. Patent 4,752,327

The technical problem of the present invention is to provide an arrangement structure of a low odor nozzle to improve the decarburization capacity and the real rate of the ferromangan decarburization furnace. In addition, the life of the decarburization furnace is extended by minimizing the cause of damage to the low-odor nozzle and the refractory. In addition, it is to provide a decarburization furnace that can respond early to the accident caused by low-odor nozzle damage.

Embodiment of the present invention is a steelmaking furnace for receiving molten steel and at least one pair of plunging nozzles are arranged opposite to each other on the basis of the center point of the bottom surface of the steelmaking furnace, and located on the opposite side relative to the reference axis that is the diameter of the bottom surface It includes.

It also includes a top lance for supplying gas at the top of the steelmaking furnace.

In addition, the pair of low odor nozzles include a charging side odor nozzle located on the charging side about the reference axis, and a tapping side odor nozzle located on the tapping side about the reference axis.

In addition, when the radius of the bottom surface is R, the pair of lower nozzles includes a first cylinder charging side lower nozzle positioned on the charging side on the first circumference, and a first cylinder positioned on the tapping side on the first cylinder. One circumferential tapping side low odor nozzle is included.

And a second circumferential charging side odor nozzle located on the charging side on the second circumference and a second circumferential tapping side odor nozzle located on the tapping side on the second circumference.

Further, the first cylindrical charging side lower nozzle and the first cylindrical landing side lower nozzle are located on the first circumference in the range of 0.32R to 0.38R at the center point of the bottom surface, and the second cylindrical charging side lower nozzle and the second cylindrical landing side The low odor nozzle is located on the second circumference in the range of 0.6R to 0.68R at the center point of the bottom surface.

In addition, the position of the first loading side odor nozzle on the first circumference and the position of the second loading side odor nozzle on the second circumference are determined so that the distance between the first loading side odor nozzle and the second loading side odor nozzle has the largest value. do.

Also, when the radius of the bottom surface is R, the charging side extraction nozzles located on different circumferences have an angle within the range of 15 ° to 30 °, and the tapping side extraction nozzles located on different circumferences are 15 ° to 30 °. It has a square angle within the range.

In addition, the reference axis is characterized in that it is parallel to the tilting axis which is the central axis of inclination of the steelmaking path.

According to the embodiment of the present invention, the low odor nozzles are disposed facing the reference axis to increase the stirring power of the decarburization furnace, thereby improving the decarburization capacity and the ferromangan error rate of the ferromangan decarburization furnace. In addition, by not placing the low-odor nozzle on the charging side and the tapping side, it is possible to extend the life of the decarburization furnace by minimizing the cause of damage to the low-odor nozzle and refractory. In addition, by arranging the low odor nozzle on the tilt shaft, even if molten steel outflow occurs due to damage to the low odor nozzle, it is possible to quickly tilt the decarburization furnace to minimize the operation accident.

1 is a view showing the arrangement of the low-odor nozzle formed on the bottom surface of the existing decarburization furnace.
FIG. 2 is a view briefly illustrating a process of charging, decarburizing, and tapping crushed steel in accordance with an embodiment of the present invention.
Figure 3 is a perspective view of the mitralized steel refining apparatus schematically showing the overall configuration of the decarburization furnace and its surrounding facilities according to an embodiment of the present invention.
Figure 4 is a view showing the appearance of the arrangement of the lower nozzle located on the bottom of the decarburization furnace in accordance with an embodiment of the present invention from the top of the decarburization furnace.
FIG. 5 is a view illustrating a state in which each of the low-nozzle nozzles is arranged at the same angle (90 °) on the same circle.
FIG. 6 is a view illustrating a state where charging side extraction nozzles and tapping side extraction nozzles located on different circumferences are arranged at an angle of 15 °.
FIG. 7 is a view illustrating a state where charging side extraction nozzles and tapping side extraction nozzles located on different circumferences are arranged at an angle of 30 °.
8 is a graph showing uniform mixing time when the lower nozzle has the arrangement structure of FIG. 4 and the arrangement structure as shown in FIG. 5 according to the present invention.
FIG. 9 is a graph showing uniform mixing time when the extraction nozzle has the arrangement structure of FIG. 6 and the arrangement structure as shown in FIG. 11 according to the present invention.
FIG. 10 is a graph showing uniform mixing time when the lower nozzle has the arrangement structure of FIG. 7 according to the present invention and the arrangement structure of FIG. 12 according to the related art.
FIG. 11 is a view showing a state in which a lower nozzle is disposed adjacent to a reference axis. FIG.
Fig. 12 is a view showing the angle of angle of the lower nozzle on the same circumference.
Figure 13 shows the end point carbon and the real rate of the decarburization furnace using the low odor arrangement of the present invention and the conventional method.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

In addition, in the following description, the molten steel is ferromanganese and the molten steel forging device will be described as an example of the ferromangan decarburization apparatus, but may be applied to various other furnaces for decarburizing.

FIG. 2 is a view briefly illustrating a process of charging, decarburizing, and tapping crushed steel in accordance with an embodiment of the present invention.

The decarburization furnace is a steel refining furnace for refining molten steel such as mitralized steel, that is, a furnace, and carbon control in molten steel can be achieved by removing and decarburizing carbon from the pulverized steel loaded in the furnace. . Hereinafter, the decarburization furnace will be described as an example of the steelmaking furnace, but it will be apparent that various steelmaking furnaces other than the decarburization furnace may be applied. For reference, decarburizing refers to a phenomenon in which the carbon content of the mithal carbon steel decreases due to the oxidation of oxygen. In other words, heating of the mithal carbon steel in the form of a solid solution occurs when oxygen in the air surrounding it penetrates therein, and decarburization may occur when the oxidation rate is less than the diffusion rate of carbon outward. In the above description, mithal carbon steel refers to molten steel in which molten iron is manufactured as molten steel in an electric furnace or converter, and thus carbon is not removed. Hereinafter, a ferro-manganese will be described as an example of mithal carbon steel, but it will be apparent that the present invention can be applied to other molten steel in addition to ferro-manganese.

After the mithal carbon steel is charged to the decarburization furnace, oxygen gas is blown to lower the carbon content, and then the tapping is carried out through the tapping hole. The process of charging, decarburizing and tapping ferromangan is briefly described with reference to FIG. 2. The fertal manganese, which is a non-talal carbon steel, is charged into the decarburization furnace 10 through the charging hole A. The tracer is provided at the charging hole, and the ferromangan is injected into the decarburization furnace along the tracer. When the ferromangan is charged into the decarburization furnace through the charging hole A, a decarburization process is performed to remove carbon in the ferromanganese. In the decarburization process, oxygen is blown from the upper part by using a lance 13 (hereinafter, referred to as 'upper lance'), and a nozzle (12; hereinafter referred to as 'lower nozzle') formed at the bottom part. The oxygen is blown in through the bottom (low odor). In addition, by bubbling by inert gas supplied from the bottom or the side, stirring is activated to homogenize the components inside the ferro-manganese and promote the chemical reaction in the ferro-manganese or surface to lower the carbon content in the ferro-manganese. For reference, the amount of carbon removed from the ferro-manganese is controllable. The amount of oxygen supplied through the upper lance 13 or the lower nozzle 12 is controlled as a mass flow controller (MFC). Therefore, if you want to remove a small amount of carbon in the ferro-manganese, control the flow controller (MFC) to reduce the amount of oxygen supplied to the decarburization furnace, on the contrary, if you want to remove a large amount of carbon in the ferro-manganese flow controller (MFC) is controlled to increase the amount of oxygen supplied to the decarburization furnace.

The ferromangan, which has completed the decarburization process through oxygen supply, has a process of tapping into the ladle (L). That is, as shown in Figure 2, by tilting the decarburization channel 10 to the tapping hole (B) which is opened at a predetermined position of the decarburization furnace to induce a natural fall of the ferro manganese by gravity to the ladle (L) located below. Make sure you are out. The tap opening (B) is made of refractory, and is implemented as a material resistant to physical and chemical abrasions generated when contacting with hot molten steel during tapping.

 Figure 3 is a perspective view of the mitralized steel refining apparatus schematically showing the overall configuration of the decarburization furnace and its surrounding facilities according to an embodiment of the present invention.

The decarburization furnace 19 which is a steelmaking furnace in the mitralized steel refining apparatus which is a molten steel refining apparatus comprises the outer surface by the iron plate of 70 mm-90 mm, The inside is comprised by refractory body. The decarburization furnace 10, which is a steelmaking furnace, is supported by the tilt shaft 15, and the weight of the decarburization furnace 10 is concentrated at the lower portion. The decarburization furnace 10 is inclined back and forth by a gear by the force transmitted from the tilting motor 14 controlled by the driver 19 to inject the mithal steel, which is the main raw material, and to pull out the decarburized molten steel into the ladle. . In some cases, various subsidiary materials, coating agents, and the like are introduced through the subsidiary material input hopper 16.

Oxygen is injected from the upper portion through the upper lance 13 located at the upper portion of the decarburization furnace 10, and a blowing operation of decarburization that injects oxygen from the lower portion is performed through a lower nozzle 12 located at the lower portion of the decarburization furnace 10. Proceed. In some cases, the amount of oxygen introduced through the upper lance 13 and the lower nozzle 12 is controlled through the flow controller 18 through the operation of the main computer 17.

In the case of the low odor nozzle 12, since it is conventionally arranged at the lower surface of the decarburization furnace, it causes the formation of a stagnant region due to the interference between the low odor nozzles, and thus, there is a problem of lowering the decarburization function in ferro manganese. In addition, there is a problem that the low odor nozzles are placed on the charging side and the tapping side, the low odor nozzle 12 is damaged or the refractory is damaged, thereby impeding the extension of life and causing an operation accident. In order to solve this problem, an embodiment of the present invention places a pair of low-density nozzles on the same circumference on the same circumference with respect to a predetermined reference axis, and positions them on opposite sides with respect to the reference axis. No area was generated.

Figure 4 is a view showing the appearance of the arrangement of the lower nozzle located on the bottom of the decarburization furnace in accordance with an embodiment of the present invention from the top of the decarburization furnace.

The extraction nozzles 12; 121a, 121b, 122a, and 122b are point-symmetrical with respect to the reference axis of the decarburization furnace, which is the steelmaking furnace, and are arranged on the same circumference, and are located on opposite sides with respect to the reference axis. Low odor nozzles inject oxygen into the decanted steel that is charged into the decarburization furnace. This reference axis is a reference axis based on the diameter of the bottom surface of the decarburization furnace, and this reference axis is determined as an axis parallel to the tilt shaft 15 of FIG. 3, which is a central axis of tilting the decarburization furnace at the time of tapping. By setting the diameter parallel to the tilting shaft in the diameter as a reference axis, the result is that the odor nozzles are arranged in parallel with the tilting shaft, thereby minimizing the operation accident due to the outflow of molten steel due to damage to the odor nozzles. That is, when molten steel outflow due to damage of the low odor nozzle occurs, the decarburization furnace is quickly tilted to allow the low odor position to be located above the water surface, thereby minimizing operation accidents.

The extraction nozzle 12 is implemented by a plurality of pairs 121a / 121b and 122a / 122b and is disposed to face each other by being point-symmetrical with respect to the center point of the bottom surface, and thus positioned on opposite sides with respect to the reference axis, which is the diameter of the bottom surface. . In general, point symmetry refers to a case where a figure is completely superimposed on an original figure when the figure is rotated 180 ° around a point. In this case, the figure is called a point symmetric figure, and a point that is the center of rotation is called a center point of point symmetry. Therefore, a pair of point symmetrical nozzles are located on opposite sides with respect to the reference axis, which is the diameter of the bottom surface. One lower nozzle is located on the right side, and the other nozzle is located on the right side. It is located on the left side opposite the center point.

The pair of low odor nozzles, which is an embodiment of the present invention, includes charging side odor nozzles 121a and 122a positioned at the charging side about the reference axis, and tapping side odor nozzles 121b and 122b positioned at the tapping side about the reference axis. do. The pair of low-density nozzles are arranged point-symmetrically on the same circumference, for example, the first circumferential charging side odor nozzle 121a located at the charging side on the first circumference C1 and the first circumferential tapping-side low-nozzle nozzle located at the tapping side 121b is arranged by point symmetry. Similarly, on the second circumference C2, the second circumferential charging side lowering nozzle 122a located on the charging side and the second circumferential tapping side lowering nozzle 122b located on the tapping side are point-symmetrically disposed about the center point and the reference axis.

Further, the first filling side lowering nozzle 121a positioned on the first circumference C1 and the second loading side lowering nozzle 122a positioned on the second circumference C2 have the largest value. The position of the 1st loading side capture nozzle 121a on one cylinder, and the position of the 2nd loading side capture nozzle 122a on a 2nd cylinder are determined. Therefore, the first tapping-side snatch nozzle 121b and the second tapping-side snatch nozzle 122b disposed to face the symmetry axis of each charging-side snatch nozzle also have a distance farthest from each other. The first and second loading side extraction nozzles 121a and 122a are close to each other on the first and second circumferences, or the first and the second landing side extraction nozzles 121b and 122b are close to each other on the first and second cylinders. This is because the stirring efficiency decreases if there is.

In addition, the first circumferential charging side odor nozzle 121a and the first circumferential tapping side odor nozzle 121b are disposed on the first circumference C1, and the first circumference C1 is the widest in the steelmaking path of the jar structure. When the radius of the circumferential surface having a circumference is R, it is located in the range of 0.32R to 0.38R from the center point of the bottom surface. Similarly, the second circumferential loading side lower nozzle and the second circumferential landing side lower nozzle are arranged on the second circumference, which is 0.6R to 0.68R at the center point of the bottom surface when R is the radius of the bottom surface. It is located at. Since the low odor nozzle is located on the circumference, eventually, the charging side odor nozzle and the exit side odor nozzle located on the circumference of the bottom face are located within 0.68R with respect to the radius R. The reason why the odor nozzle is located within the radius range is that if the odor nozzle is installed within 0.32R based on the radius R, the stirring effect is reduced by the interference of the gas ejected from the odor nozzle and the odor gas, thereby decarburizing the odor gas. This is because the performance is lowered. On the contrary, when the low odor nozzle is provided at 0.68R or more, the wall refractory is melted and damaged by the low odor gas. Therefore, the embodiment of the present invention installs the low odor nozzle at 0.32R ~ 0.68R. For reference, the decarburization furnace generally has a convex jar structure in which the middle portion of the middle layer is lower than the bottom surface or the upper surface, and the convex portion has the widest circumference. Therefore, the radius R in the above corresponds to the radius of the convex center portion of this decarburization furnace.

On the other hand, the agitation performance is influenced by the angle between the charging side lower nozzle and the tapping side lower nozzle which are disposed opposite to the center of the reference axis on the same circumference. For example, as shown in FIG. 5, when the respective low odor nozzles are arranged at the same angle (90 °) on the same circle, each low odor nozzle is stirred for 4 minutes by the decarburization furnace, so that the low Where the flow stagnant zone is created. Since the low odor nozzles are arranged in close proximity, mutual interference between low odor gases occurs, leading to loss of momentum of the low odor gas, thereby reducing agitation performance.

In order to solve this problem, the angle between the charging-lower nozzle and the tapping-lower nozzle has a value within a certain range. To this end, an embodiment of the present invention is to form a rotary flow by arranging the extraction nozzles disposed opposite to the center of the reference axis on the same circumference at the angle of 15 ° to 30 ° in the 0.35R and 0.65R position to form a rotary flow to agitate the decarburization furnace Improve. When the radius of the most convex center portion of the jar decarburization furnace is R, the charging side depression nozzles located on different circumferences have angles in the range of 15 ° to 30 °, and the tapping sides located on different circumferences. Lower nozzles have an angle within the range of 15 ° to 30 °. For reference, FIG. 6 is a view illustrating a state where charging side lower nozzles and tapping side lower nozzles positioned on different circumferences are arranged at a 15 degree angle, and FIG. 7 is a side of the charging side positioned on different circumferences. It is a figure which shows that the low nozzle and the tapping side low nozzles are arrange | positioned with the angle of 30 degrees.

The reason why the charging side extraction nozzles and the tapping side extraction nozzles positioned on different circumferences as shown in FIG. 6 or 7 to have the angle between 15 ° and 30 ° is as follows.

When the low odor array is formed at an angle of 15 ° or less, mutual interference between low odor gases is generated by the adjacent low odor positions, and thus the stirring ability is reduced due to the loss of momentum. In other words, when the low odor array is formed at 15 ° or less, the agitation performance decreases due to mutual interference between the low odor gases, and when the low odor is disposed on the same circumference, the flow field is evenly distributed by decarburization to form a stagnant region, resulting in a decrease in the agitation performance. . In addition, when the angle between the low odor nozzles is 30 °, the low odor nozzles can be arranged in point symmetry, and rotational flow can be formed, but the distance between the low odor nozzles is farther, and the rotational flow is weakened, resulting in less stirring force. This is because if a low odor array having a point symmetry is formed in order not to form a stagnant region, excellent stirring force is obtained by the formation of rotational flow, but the stirring force is weakened because the distance between the low odors is greater than 30 °.

On the other hand, the example of the low odor nozzle in the above-mentioned mitralized steel refining apparatus is arranged for the decarburization process by introducing oxygen. However, the present invention is not limited thereto, and may be applied to the arrangement of the low-odor nozzle in various processes in which the decarburization process is used.

Meanwhile, FIG. 8, 9 and 10 show uniform mixing times measured by performing experiments by constructing a water model experiment apparatus having respective low-odor nozzle arrangement structures.

In the water model test, an acrylic bath with a quarter of commercial 40ton permanganese decarburization furnace was fabricated, water was used as a substitute for ferromanganese molten steel, and the upper and lower odor gases were tested using nitrogen. In order to compare the stirring ability by the low odor arrangement, the flow rates of the upper and lower odor gases were kept the same, and the low odor arrangement was changed to measure the uniform mixing time in the decarburization furnace. In the homogeneous mixing time measurement method, when the flow in the decarburization furnace reached a steady state, 50mml of saturated KCl solution was added into the decarburization furnace, and the electrical conductivity of the bottom and wall surfaces was measured, and the concentration time of the concentration field was measured.

8 is a graph showing uniform mixing time when the lower nozzle has the arrangement structure of FIG. 4 and the arrangement structure as shown in FIG. 5 according to the present invention. Referring to Figure 8, the low odor arrangement of the present invention can be seen that the uniform mixing time is shorter than the conventional method in the stirring conditions of the general blowing pattern. In the conventional low-nozzle nozzle arrangement, each low-nozzle nozzle is arranged at the same circle (90 °) in the same circle, and each low-nozzle nozzle is stirred for 4 minutes by decarburization, so the four flow stagnant zones are caused by interference between the low-nozzle nozzles. Is generated. However, the low odor nozzle arrangement structure of the present invention improves the stirring ability of the decarburization furnace by forming rotational flow by arranging them at positions of 15 ° at positions 0.35R and 0.65R.

FIG. 9 is a graph showing uniform mixing time when the extraction nozzle has the arrangement structure of FIG. 6 and the arrangement structure as shown in FIG. 11 according to the present invention.

FIG. 6 shows the uniform mixing time of the four-hole low odor array arranged on the same circumference (0.5R) while forming the angle between the low odor array of the present invention and the low odor nozzle at 15 ° as shown in FIG. 11. 6 and 11 have the same angle between the low odor nozzles, but the low odor array of FIG. 6, which is the low odor array structure of the present invention, can be obtained in the stirring condition when compared to the low odor array structure of FIG. 11. In the case of arranging the four-hole low odor nozzles on the same circumference as shown in FIG. 11, the low odor nozzle pairs having an angle of 15 ° are arranged in a line symmetry, and the decarburization furnace is stirred for 2 minutes to generate a flow stagnant region. In addition, the low odor nozzles are disposed in close proximity, and mutual interference between low odor gases occurs, leading to loss of momentum of the low odor gas, thereby reducing agitation performance. However, in the case of the present invention, as shown in Figure 6, by placing the low odor nozzles in a point-symmetrical opposite position at 15 ° angle at 0.35R and 0.65R position to form a rotary flow and the interference between the low odor gas is not generated by the stirring ability of the decarburization furnace Can improve.

FIG. 10 is a graph showing uniform mixing time when the lower nozzle has the arrangement structure of FIG. 7 according to the present invention and the arrangement structure of FIG. 12 according to the related art.

FIG. 7 shows the uniform mixing time of the four-hole low odor nozzle array formed at the positions of 0.35R and 0.65R with the angle between the low odor array and the low odor nozzle of 30 ° as shown in FIG. 12. The arrangement of the four low-odor nozzles on the 0.35R and 0.65R circumferences is the same, but when the low-odor array of FIG. 7 of the present invention is compared with the low-odor array of FIG. 12, excellent stirring ability can be obtained under the stirring conditions of a general blow pattern. When the angle between low odor nozzles is 30 °, the low odor nozzles are arranged in point symmetry, but rotational flow can be formed, but the distance between the low odor nozzles is farther, and thus the rotational flow is weakened, thus having a weaker stirring force than the present invention.

As a result, as a result of comparing the uniform mixing time in the low odor arrangement structure of FIGS. 4, 6, and 7 and the conventional low odor arrangement structure of FIGS. 5, 11, and 12, when the low odor arrangement is formed at 15 ° or less, It can be seen that the lowering of the stirring ability due to the interference and when the low odor is disposed on the same circumference, the decarburizing flow field is evenly distributed to form a stagnant region, thereby lowering the stirring ability. If a low odor arrangement in the form of point symmetry is formed in order not to form a stagnant region, excellent stirring force is obtained by the formation of rotational flow, but the stirring force is weakened because the distance between the low odors is greater than 30 °.

For reference, FIG. 13 shows the terminal carbon and FeMn real ratios of the 300 kg FeMn decarburization furnace using the low odor arrangement of the present invention and the conventional method. By applying the same blowing pattern (uptake blowing pattern, low odor flow rate, lance height, etc.) in the same manner, the conventional method is 20 times and the present invention is carried out 8 times. It can be seen that it is superior to the method of.

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

10: decarburization furnace 12: odor nozzle
13: Uplift lance 14: tilt motor
15: tilting shaft 16: feeding hopper
121a: 1st circumferential loading side odor nozzle 121b: 1st circumferential tapping side odor nozzle
122a: 2nd circumferentially charged side odor nozzle 122b: 2nd circumferentially loaded side odor nozzle
C1: 1st column C2: 2nd column

Claims (9)

Steelmaking furnace for receiving molten steel;
At least one pair of plunging nozzles disposed opposite to each other on a basis of a center point of the bottom surface of the steelmaking furnace, and positioned opposite to each other based on a reference axis that is a diameter of the bottom surface;
Molten steel refining apparatus comprising a. The method according to claim 1,
A top lance for supplying gas from an upper portion of the steelmaking furnace;
Molten steel refining apparatus comprising a. The method according to claim 1, wherein the pair of lower nozzle,
A charging side odor nozzle located at the charging side about the reference axis;
A tapping side suction nozzle positioned on the tapping side with respect to the reference axis;
Molten steel refining apparatus comprising a. The method according to claim 3, wherein the pair of lower nozzles, when the radius of the circumferential surface having the widest circumference in the steelmaking furnace of the jar structure as R,
A first circumferential charging side odor nozzle located on the charging side on a first circumference;
A first circumferential tapping side odor nozzle located on the tapping side on the first circumference;
Molten steel refining apparatus comprising a. The method of claim 4,
A second circumferential charging side odor nozzle located on the charging side on a second circumference;
A second circumferential tapping side odor nozzle located on the tapping side on the second circumference;
Molten steel refining apparatus comprising a. The method of claim 5, wherein the first cylindrical charging side odor nozzle and the first cylindrical landing side odor nozzle is located on the first circumference of 0.32R ~ 0.38R range from the center point of the bottom surface, A molten steel refining apparatus, wherein the second cylinder tapping-side lower nozzle is located on the second cylinder in a range of 0.6R to 0.68R from the center point of the bottom surface. The position of the first charging side lowering nozzle on the first circumference and the second loading side lowering on the second circumference of claim 5, so that the distance between the first charging side lowering nozzle and the second charging side lowering nozzle has the largest value. Molten steel refiner, the position of the nozzle is determined. The method according to claim 3 to 7, wherein when the radius of the circumferential surface having the widest circumference in the jar-shaped steelmaking furnace is R, the charging side lower nozzles located on different circumferences have a different angle within the range of 15 ° to 30 °. And the tapping side bottom nozzles located on different circumferences have a square angle within a range of 15 ° to 30 °. The molten steel refining apparatus according to claim 1, wherein the reference axis is parallel to a tilting shaft which is a central axis of inclining the steelmaking path.

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