Integrated spray apparatus for melting furnace and control method therefor

Abstract

An integrated spray apparatus for a melting furnace according to the present invention may comprise: a main body comprising an spray nozzle provided to spray a supply fluid containing one or more fluids into the inside of the melting furnace, an oxygen supply line for flowing oxygen toward the spray nozzle, and a combined supply line for selectively flowing fuel or outside air toward the spray nozzle; and a jet supply line for selectively flowing a deflection-control jet to the front side of the oxygen supply line and the combined supply line.

Description

Integrated injection device for a melting furnace and control method thereof

[0001] The present invention relates to an integrated injection device for a melting furnace and a control method thereof.

[0002] Generally, in electric furnaces, LNG auxiliary burners are used for preheating and melting scrap during the initial stages of operation, and supersonic oxygen lances are used during the refining stage.

[0003] In this process, the LNG auxiliary burner is utilized as a supplementary device to control the thermal balance inside the electric furnace, and mixing and combustion technologies for the oxidizer and LNG are applied. In such LNG-oxygen mixed combustion, it is important to secure the experimental maximum combustion temperature relative to the theoretical adiabatic flame temperature.

[0004] Accordingly, equipment performance is being secured by utilizing shear or swirl for effective mixing of oxidizer and fuel, and efforts are being made to ensure maximum combustion efficiency through the control of flame propagation speed and flow discharge speed.

[0005] However, the LNG burners currently in use are fixed to the furnace wall, making heat transfer control over the entire molten metal surface in the electric furnace inefficient, and there is a problem that efficient use is limited as the position of the scrap or molten steel surface changes depending on the process stage.

[0006] Meanwhile, supersonic oxygen lances are used for scrap cutting and scrap collapse during the initial stages of operation, and in refining machines, supersonic oxygen is blown in to facilitate refining through oxidation reactions with impurities such as carbon at the top of the molten steel. However, current supersonic oxygen lances have a limitation in that their performance is fixed as the nozzle shape is determined by the supply flow rate and pressure.

[0007] To address these issues, the development of lances with enhanced performance utilizing shrouding flames is being pursued; however, there are limitations to their application in actual operations due to the need to consider the economic feasibility between energy consumption costs and the performance enhancement effects when using additional energy sources such as flames.

[0008] Therefore, measures to resolve these problems are required.

[0009] [Prior Art Literature]

[0010] [Patent Literature]

[0011] (Patent Document 0001) Korean Published Patent No. 10-1997-0043111

[0012] The present invention aims to solve the aforementioned conventional problems and provides an integrated injection device for a melting furnace and a control method thereof, which can selectively implement the functions of a burner and a lance through a single integrated device while effectively controlling the injection direction and flow characteristics of the supply fluid.

[0013] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0014] An integrated injection device for a melting furnace according to one embodiment for solving the above problem may include: an injection nozzle provided to inject a supply fluid containing one or more fluids into the inside of the melting furnace; a main body including an oxygen supply line that flows oxygen toward the injection nozzle and a composite supply line that selectively flows fuel or outside air toward the injection nozzle; and a jet supply line that selectively flows a jet for deflection control in front of the oxygen supply line and the composite supply line.

[0015] In addition, the above-mentioned injection nozzle may be formed such that the cross-sectional area of ​​the internal passage gradually increases from the rear to the front.

[0016] And the oxygen supply line may include a constricted section located behind a pre-set constriction point and formed such that the cross-sectional area of ​​the internal passage gradually decreases, and an expanded section connected to the constricted section and located in front of the constriction point and formed such that the cross-sectional area of ​​the internal passage gradually increases.

[0017] At this time, a mixing space may be formed in the front section of the main body, in which oxygen flowed through the oxygen supply line and fuel or outside air flowed through the composite supply line are discharged and mixed.

[0018] In addition, the front-to-back length of the above-mentioned spray nozzle may be formed to be longer than the front-to-back length of the above-mentioned mixing space.

[0019] In addition, the above-mentioned composite supply line can be formed to wrap around the circumference of the above-mentioned oxygen supply line.

[0020] Meanwhile, the above-mentioned combined supply line may include a switching valve that selectively controls the supply and cutoff of fuel or outside air.

[0021] And the above jet supply line may be provided at the connection point between the main body and the injection nozzle.

[0022] In addition, multiple jet supply lines may be arranged along the circumference of the main body and the injection nozzle.

[0023] In addition, a control method for an integrated injection device for a melting furnace according to one embodiment for solving the above problem may include: (a) a step in which a device control unit sets the operating mode of the integrated injection device for a melting furnace to either a burner mode or a lance mode; (b1) a step in which, if the operating mode set in step (a) is a burner mode, the device control unit controls oxygen to be supplied through the oxygen supply line of the integrated injection device for a melting furnace and controls fuel to be supplied through the composite supply line so that a supply fluid is injected into the furnace side of the melting furnace through an injection nozzle; and (b2) a step in which, if the operating mode set in step (a) is a lance mode, the device control unit controls oxygen to be supplied through the oxygen supply line of the integrated injection device for a melting furnace and controls fuel supply through the composite supply line to be blocked so that a supply fluid is injected into the furnace side of the melting furnace through an injection nozzle.

[0024] At this time, the above step (b1) may include a step (b1-1) in which the device control unit controls the flow rate of oxygen flowing through the oxygen supply line to supply it to the injection nozzle side; a step (b1-2) in which the device control unit controls a switching valve provided in the composite supply line to block the supply of outside air; a step (b1-3) in which the device control unit controls the flow rate of fuel flowing through the composite supply line to supply it to the injection nozzle side; and a step (b1-4) in which the device control unit selectively supplies a jet for deflection control through the jet supply line of the integrated injection device for the melting furnace to control the injection direction of the supply fluid.

[0025] And in step (b1-3) above, the device control unit can control the flow rate of fuel flowing through the composite supply line to be 25% or less of the flow rate of oxygen flowing through the oxygen supply line.

[0026] In addition, step (b1-4) above allows the device control unit to control the flow rate of the deflection control jet flowing through the jet supply line to be 13% or less of the oxygen flow rate flowing through the oxygen supply line.

[0027] In addition, the above step (b2) may include a step (b2-1) in which the device control unit controls the flow rate of oxygen flowing through the oxygen supply line to supply it to the injection nozzle side, a step (b2-2) in which the device control unit controls a switching valve provided in the complex supply line to cut off the supply of fuel, and a step (b1-3) in which the device control unit controls a switching valve provided in the complex supply line to cut off the supply of outside air or controls the flow rate of outside air flowing through the complex supply line to supply it to the injection nozzle side, thereby controlling the injection distance of the supply fluid.

[0028] Specific details of other embodiments are included in the detailed description and drawings.

[0029] According to an embodiment of the present invention, the integrated injection device for a melting furnace and the control method thereof can selectively implement the functions of a burner and a lance in a single integrated device, thereby improving the space utilization of the equipment while simplifying the structure of the device, which has the advantage of improving the space utilization of the equipment.

[0030] In addition, the present invention has the advantage of being able to effectively respond to various process conditions required within a melting furnace, as it is capable of switching between a burner mode that controls the injection direction of a supply fluid containing oxygen and fuel and a lance mode that controls the injection distance of a supply fluid that selectively includes external air in addition to oxygen.

[0031] In particular, the present invention has the advantage of being able to achieve uniform heat transfer and melting effects throughout the furnace, as the direction and speed of the supply fluid sprayed through the spray nozzle can be controlled by selectively supplying a jet for deflection control.

[0032] In addition, the present invention has the advantage of being able to selectively supply fuel or ambient air through a combined supply line, thereby securing optimal flow characteristics required for each process stage.

[0033] The effects according to the embodiments are not limited to those exemplified above, and a wider variety of effects are included in this specification.

[0034] FIG. 1 is a drawing showing the external appearance of an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0035] FIG. 2 is a diagram showing the internal structure of an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0036] FIG. 3 is a diagram showing the entire process of a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0037] FIG. 4 is a diagram showing the detailed operation process of the burner mode in a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0038] FIG. 5 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention in a state where it is operated in burner mode.

[0039] FIG. 6 is a diagram showing the detailed operation process of the lance mode in a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0040] FIG. 7 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention, in a state where no outside air is supplied and the device is operated in lance mode.

[0041] FIG. 8 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention, in a state where external air is supplied and operated in lance mode.

[0042] FIG. 9 is a graph showing the center of flow velocity according to the axial distance of the supply fluid when an integrated injection device for a melting furnace according to one embodiment of the present invention is operated in lance mode.

[0043] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0044] In this specification, where a component (or region, layer, part, etc.) is described as being "on," "connected," or "combined" with another component, it means that it may be directly placed / connected / combined with the other component, or that a third component may be placed between them.

[0045] Identical reference numerals denote identical components. Additionally, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the effective illustration of the technical content.

[0046] "And / or" includes all one or more combinations that the associated configurations can define.

[0047] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0048] Additionally, terms such as "below," "lower side," "above," and "upper side" are used to describe the relationships between the components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0049] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Additionally, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and are explicitly defined herein unless interpreted in an ideal or overly formal sense.

[0050] Terms such as "include" or "have" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0051] FIG. 1 is a drawing showing the exterior of an integrated injection device for a melting furnace according to one embodiment of the present invention, and FIG. 2 is a drawing showing the internal structure of an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0052] As illustrated in FIGS. 1 and 2, the integrated injection device for a melting furnace in this embodiment may include an injection nozzle (100), a main body (200), and a jet supply line (300).

[0053] Furthermore, the integrated injection device for a melting furnace according to the present embodiment can selectively implement the functions of a burner and a lance in a single integrated device. That is, the integrated injection device for a melting furnace according to the present embodiment can switch between a burner mode and a lance mode by controlling the injection direction or injection distance of a supply fluid containing one or more of oxygen, fuel, and ambient air, thereby effectively responding to various process conditions required within the melting furnace.

[0054] The injection nozzle (100) is provided to inject a supply fluid containing one or more fluids into the furnace side of the melting furnace.

[0055] In this embodiment, the injection nozzle (100) may have an inner surface that is inclined so that the cross-sectional area of ​​the internal passage gradually expands from the rear to the front. Such a shape converts the pressure energy of the supply fluid into kinetic energy to increase the injection speed and can assist in the uniform diffusion of the fluid.

[0056] And the spray nozzle (100) can be implemented in various forms. For example, the cross-sectional shape of the internal passage of the spray nozzle (100) can be formed as a circle, ellipse, polygon, etc., and the slope of the cross-sectional area expansion section can be changed uniformly or non-linearly.

[0057] In addition, the outlet shape of the injection nozzle (100) may be varied according to the injection pattern of the supply fluid. However, the shape of the injection nozzle (100) is not limited to this shape only.

[0058] The main body (200) may include an oxygen supply line (210) and a composite supply line (220).

[0059] Among these, the oxygen supply line (210) is a passage that supplies oxygen into the melting furnace, and can control the flow rate and volume of oxygen according to process conditions.

[0060] Oxygen supplied through such an oxygen supply line (210) is mixed with fuel to cause a combustion reaction in burner mode, and in lance mode, is injected in the form of a supersonic jet to perform scrap cutting or molten steel refining operations.

[0061] Meanwhile, in the following description, the front and rear directions are defined based on the direction in which oxygen flows in the oxygen supply line (210). This corresponds to the x-axis of the three-dimensional orthogonal coordinate system shown in FIG. 1, and since oxygen flows from the rear to the front, the positive direction of the x-axis becomes the front.

[0062] In addition, the y-axis is defined as a direction perpendicular to the x-axis on the horizontal plane, and this can serve as a reference for representing the transverse component of oxygen flow in the horizontal direction of the melting furnace.

[0063] The z-axis is defined as a direction perpendicular to the plane formed by the x-axis and y-axis, and this can serve as a reference for the vertical component of the melting furnace.

[0064] And the combined supply line (220) is a passage that selectively supplies fuel or outside air depending on the operating mode, and can supply fuel for combustion in burner mode and outside air to improve the characteristics of the oxygen jet in lance mode.

[0065] The combined supply line (220) can control the type and flow rate of the fluid through the switching valve (221), thereby enabling optimal flow characteristics suitable for process conditions.

[0066] More specifically, in this embodiment, the oxygen supply line (210) may be configured in the shape of a Venturi tube including a constricted section (211) and an expanded section (212) based on the constricted section (213), with a constricted section (213) formed therein.

[0067] The constriction section (211) is located behind the constriction point (213) and is formed so that the cross-sectional area of ​​the internal passage gradually decreases, and the oxygen flow rate can be increased. Additionally, the expansion section (212) is located in front of the constriction point (213) and is formed so that the cross-sectional area of ​​the internal passage gradually increases, and the oxygen injection range can be expanded.

[0068] Meanwhile, in this embodiment, a mixing space (230) may be formed in the front portion of the main body (200). In such a mixing space (230), oxygen flowing through the oxygen supply line (210) and fuel or outside air flowing through the composite supply line (220) may be discharged and mixed.

[0069] At this time, the front-to-back length (d1) of the spray nozzle (100) can be formed to be longer than the front-to-back length (d2) of the mixing space (230), thereby ensuring sufficient mixing and spraying distance.

[0070] In addition, in this embodiment, the composite supply line (220) is formed to wrap around the circumference of the oxygen supply line (210) in an annular shape, and the supply and blocking of fuel or outside air can be selectively controlled through the switching valve (221).

[0071] The annular structure of such a composite supply line (220) assists in the uniform mixing of oxygen and fuel, or oxygen and outside air, and enables efficient combustion in burner mode and improved flow characteristics through the inflow of outside air in lance mode.

[0072] The jet supply line (300) is a component that selectively flows a jet for deflection control in front of the oxygen supply line (210) and the composite supply line (220), and can deliver chemical energy to a desired location inside the melting furnace by controlling the injection direction of the supply fluid.

[0073] In this embodiment, the jet supply line (300) is provided at the connection point between the main body (200) and the injection nozzle (100), and may have a configuration in which a plurality of them are arranged along the circumference of the main body (200) and the injection nozzle (100).

[0074] In particular, in the present embodiment, the jet supply line (300) is exemplified as being arranged in four slots at 90-degree intervals, and such a slot-shaped structure can control the injection direction and range of the deflection control jet.

[0075] And the jet supply line (300) can control the direction of injection of the supply fluid by pressurizing and supplying compressed air or oxygen, and such deflection control through the jet supply line (300) enables the delivery of chemical energy to a desired location inside the melting furnace.

[0076] For example, the jet supply line (300) can be controlled in a single direction through one of the multiple lines, or can perform complex direction control through two or more lines.

[0077] When a single line is used, the supply fluid can be deflected and injected in a specific direction by a deflection control jet supplied through that line. When direction is controlled through two or more lines, the injection direction of the supply fluid can be controlled more precisely by setting the jet flow rates of each line differently.

[0078] For example, by supplying jets of different flow rates for deflection control to two adjacent jet supply lines, the supply fluid can be deflected in the intermediate direction between the two lines, and the deflection angle can be finely adjusted by controlling the difference in flow rates between each line. Through such a composite control method, precise directional control can be achieved for all areas inside the melting furnace. However, the jet supply lines (300) can be implemented in various forms, and their number, angle, shape, etc., can be changed depending on the size of the melting furnace or operating conditions.

[0079] Meanwhile, as described above, the integrated injection device for a melting furnace of the present embodiment can be driven in a burner mode or a lance mode by controlling the injection direction or injection distance of a supply fluid containing one or more of oxygen, fuel, and ambient air.

[0080] In burner mode, oxygen and fuel are mixed to form a flame, and in lance mode, supersonic oxygen is supplied to perform scrap cutting and refining operations. In particular, in lance mode, outside air can be introduced through the switching valve (221) of the composite supply line (220) to improve the straightness and penetration power of the oxygen jet.

[0081] Meanwhile, in this embodiment, oxygen is a fluid supplied through the oxygen supply line (210), which is mixed with fuel to cause a combustion reaction in burner mode, and is injected at supersonic speed in lance mode to perform scrap cutting or molten steel refining operations.

[0082] And the fuel is a fluid supplied through the combined supply line (220), which can be defined as a fluid that is mixed with oxygen in burner mode to cause a combustion reaction, and may be, for example, LNG. In addition, the outside air is air introduced through the switching valve (221) of the combined supply line (220), which can be defined as a fluid that improves the straightness and penetration power of supersonic oxygen in lance mode.

[0083] The jet for deflection control is a fluid that is selectively supplied through the jet supply line (300) and can be defined as a fluid that controls the injection direction of the supply fluid in burner mode.

[0084] In addition, in this embodiment, the supply fluid is a fluid injected into the furnace side of the melting furnace through the injection nozzle (100), and may be composed of a combination of fluids selected from oxygen, fuel, and outside air depending on the operating mode.

[0085] Hereinafter, the process of controlling an integrated injection device for a melting furnace according to one embodiment of the present invention described above will be explained in detail.

[0086] FIG. 3 is a diagram showing the entire process of a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0087] As illustrated in FIG. 3, the control method of an integrated injection device for a melting furnace according to the present invention can be performed by a device control unit, and the process may include steps (a), (b1), and (b2).

[0088] (a) Step is the process of setting the operating mode of the integrated injection device for the melting furnace to either burner mode or lance mode by the device control unit.

[0089] That is, the device control unit can selectively set the operating mode of the integrated injection device for the melting furnace according to the stage of the operation process.

[0090] For example, it can be set to burner mode when preheating and melting of scrap is required during the initial stages of operation, or when heat balance control inside the electric furnace is required.

[0091] On the other hand, if scrap cutting and scrap collapse are required in the section from the middle of the melting machine to the refining machine, or if refining is required through an oxidation reaction with impurities (P, Si, C, etc.) at the top of the molten steel, it can be set to lance mode.

[0092] At this time, when the operating mode is set to burner mode, the device control unit can perform step (b1) of controlling oxygen to be supplied through the oxygen supply line (210) and controlling fuel to be supplied through the composite supply line (220) so that the supply fluid is injected into the furnace side of the melting furnace through the injection nozzle (100).

[0093] And when the operating mode is set to lance mode, the device control unit can perform step (b2) of controlling oxygen to be supplied through the oxygen supply line (210) and controlling fuel supply through the composite supply line (220) to be blocked so that the supply fluid is injected into the furnace side of the melting furnace through the injection nozzle (100).

[0094] Below, we will explain the details of these burner modes and lance modes in more detail.

[0095] FIG. 4 is a diagram showing the detailed operation process of the burner mode in a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0096] As illustrated in FIG. 4, in burner mode, the device control unit can perform the following detailed steps.

[0097] First, the device control unit can perform step (b1-1) of controlling the flow rate of oxygen flowing through the oxygen supply line (210) so that it is supplied to the injection nozzle (100).

[0098] Next, the device control unit can perform step (b1-2) of blocking the supply of outside air by controlling the switching valve (221) provided in the composite supply line (220). This is to improve combustion efficiency in burner mode.

[0099] Next, the device control unit can perform step (b1-3) of controlling the flow rate of fuel flowing through the composite supply line (220) so that it is supplied to the injection nozzle (100).

[0100] In this embodiment, the device control unit can control the flow rate of fuel flowing through the composite supply line (220) to be 25% or less (e.g., 1 / 4.4) of the flow rate of oxygen flowing through the oxygen supply line (210), and this is to optimize combustion efficiency.

[0101] Such a relationship between fuel and oxidizer flow rates can affect combustion efficiency and flame temperature. To this end, the theoretical fuel / oxidizer ratio can be calculated using the oxygen-fuel complete reaction equation, and the actual flow rate ratio can be set based on this.

[0102] Although the flame temperature may be highest when the fuel / oxidizer ratio is 1.1 times the theoretical value, in this embodiment, it may be set to 0.9 times the theoretical value considering the energy efficiency of the electric furnace process. Combustion efficiency may vary depending on the setting of such a flow rate ratio, and changes in discharge velocity due to the flow rate may affect combustion efficiency.

[0103] Accordingly, the device control unit can control the flow rate of fuel flowing through the composite supply line (220) to be 25% or less of the flow rate of oxygen flowing through the oxygen supply line (210). This is to optimize energy efficiency in the electric furnace process.

[0104] And the device control unit can further perform step (b1-4) of controlling the injection direction of the supply fluid by selectively supplying a jet for deflection control through the jet supply line (300).

[0105] In this embodiment, the device control unit can control the flow rate of the deflection control jet flowing through the jet supply line (300) to be 13% or less of the oxygen flow rate flowing through the oxygen supply line (210). This is intended to effectively control the direction of the supply fluid while preventing excessive deflection.

[0106] For example, such a jet supply line (300) can spray a deflection control jet at a total of four locations at 90-degree intervals in the tangential direction.

[0107] In the case of this embodiment, when a jet for deflection control is discharged through only one jet supply line, an axial deflection of about 10 degrees may occur in the opposite direction of the discharged jet.

[0108] In addition, when jets for deflection control are simultaneously discharged through two jet supply lines spaced 180 degrees apart in the tangential direction, an axial deflection of approximately 10 degrees may occur in the direction of approximately 150 degrees of the discharged jet. Through such deflection control, the injection direction of the supply fluid can be precisely controlled.

[0109] As such, the present embodiment can secure optimal operating conditions in burner mode through step-by-step control.

[0110] FIG. 5 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention in a state where it is operated in burner mode.

[0111] As illustrated in FIG. 5, in this embodiment, when operating in burner mode, oxygen is supplied through the oxygen supply line (210) and fuel can be supplied through the composite supply line (220). When a jet for deflection control is selectively supplied through the jet supply line (300), the injection direction of the supply fluid can be controlled.

[0112] As can be seen in the computational analysis image of FIG. 5, the supply fluid can be deflected and sprayed in a specific direction by a deflection control jet supplied through the jet supply line (300). Such deflection control allows the spraying direction of the supply fluid to be controlled even if the equipment is fixed to the furnace wall.

[0113] Therefore, effective heat transfer control over the entire molten metal surface within the melting furnace is possible, and uniform disintegration of scrap and alternative materials can be induced in the melter.

[0114] In addition, it can be confirmed that the supply fluid is effectively controlled in the desired direction through the distribution of the flow field shown in the computational analysis results.

[0115] FIG. 6 is a diagram showing the detailed operation process of the lance mode in a control method for an integrated injection device for a melting furnace according to one embodiment of the present invention.

[0116] As illustrated in FIG. 6, in lance mode, the device control unit can perform the following detailed steps.

[0117] First, the device control unit can perform step (b2-1) of supplying supersonic oxygen through the oxygen supply line (210) in the section from the middle of the melter to the refiner within the melting furnace. At this time, the straightness of the supersonic oxygen is important, and as the straightness increases, the cutting efficiency for the scrap can be improved.

[0118] And the device control unit can perform step (b2-2) of blocking the supply of fuel by controlling the switching valve (221) provided in the composite supply line (220).

[0119] Additionally, the device control unit can perform step (b2-3) of controlling the injection distance of the supply fluid by controlling the switching valve (221) provided in the composite supply line (220) to block the supply of outside air, or by controlling the flow rate of outside air flowing through the composite supply line (220) to supply it to the injection nozzle (100).

[0120] In this process, if the supply of outside air is cut off, the system can be operated in a pure lance mode using only supersonic oxygen; however, if outside air is supplied, it naturally rides along with the lance flow rate, thereby improving the straightness and penetration power of the supersonic oxygen. Through such selective control of the outside air supply, performance in lance mode can be optimized to suit process conditions.

[0121] In other words, the lance mode can be driven from the middle of the melting furnace to the refining furnace for scrap cutting and impurity removal. In particular, improved straightness allows for effective removal of impurities such as P, Si, and C by penetrating slag and molten steel in the refining furnace, and the reduced cavity radius due to high straightness also enables a reduction in FeO within the molten steel.

[0122] FIG. 7 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention, in a state where no outside air is supplied and the device is operated in lance mode.

[0123] In FIG. 7, the flow characteristics can be observed in a state where supersonic oxygen is supplied through the oxygen supply line (210) in lance mode and the supply of outside air through the switching valve (221) of the combined supply line (220) is blocked.

[0124] In this process, a supersonic oxygen supply flow rate is supplied, and the fuel supply and external air supply flow rates through the combined supply line (220) are cut off to zero by the control of the switching valve (221). In addition, the supply flow rate for deflection control through the jet supply line (300) also becomes zero.

[0125] Through the computational analysis image of Fig. 7, the injection pattern of supersonic oxygen and the characteristics of the flow field formation can be confirmed, which represent the basic operating conditions in lance mode.

[0126] FIG. 8 is a diagram showing a computational analysis image of an integrated injection device for a melting furnace according to one embodiment of the present invention, in a state where external air is supplied and operated in lance mode.

[0127] In FIG. 8, the flow characteristics can be observed in a state where supersonic oxygen is supplied through the oxygen supply line (210) in lance mode and outside air is supplied through the switching valve (221) of the combined supply line (220).

[0128] In this state where outside air is supplied, a supersonic oxygen supply flow rate is supplied, and the switching valve (221) of the combined supply line (220) opens the outside air passage so that outside air can flow in. At this time, the jet supply flow rate for deflection control through the jet supply line (300) becomes 0.

[0129] Through the computational analysis image of Fig. 8, it can be seen that the outside air naturally rides along with the lance flow rate, increasing the potential core length and average speed of the lance, and also that the straightness of supersonic oxygen is improved and the flow field is formed more stably when the outside air is introduced.

[0130] This means that by infiltrating slag and molten steel in the refiner, the efficiency of removing impurities such as P, Si, and C is improved, and the effect of reducing FeO in the molten steel due to the reduction in cavity radius can be achieved.

[0131] FIG. 9 is a graph showing the center of flow velocity according to the axial distance of the supply fluid when an integrated injection device for a melting furnace according to one embodiment of the present invention is operated in lance mode.

[0132] As shown in FIG. 9, when the supply fluid is operated in lance mode, the change in the center of flow velocity according to the supersonic oxygen supply and the external air supply on / off state of the switching valve (221) can be observed.

[0133] Specifically, referring to the graph in Fig. 9, it can be seen that when the switching valve (221) is controlled to supply outside air, the average velocity of the flow center increases and the potential core length increases.

[0134] In other words, this characteristic means that straightness in lance mode can be improved, thereby enhancing the efficiency of scrap cutting and refining operations.

[0135] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing the technical concept or essential features thereof. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[0136] [Explanation of the symbol]

[0137] 100: Spray nozzle

[0138] 200: Main body

[0139] 210: Oxygen supply line

[0140] 211: Priestess Department

[0141] 212: Expansion section

[0142] 213: Point of stenosis

[0143] 220: Combined supply line

[0144] 221: Changeover valve

[0145] 230: Mixed space

[0146] 300: Jet supply line

Claims

1. A spray nozzle provided to spray a supply fluid containing one or more fluids into the furnace side of a melting furnace; A main body comprising an oxygen supply line for flowing oxygen toward the injection nozzle and a composite supply line for selectively flowing fuel or outside air toward the injection nozzle; and A jet supply line that selectively flows a deflection control jet in front of the oxygen supply line and the composite supply line; including, Integrated injection device for melting furnaces.

2. In Paragraph 1, The above-mentioned spray nozzle is formed such that the cross-sectional area of ​​the internal passage gradually increases from the rear to the front, Integrated injection device for melting furnaces.

3. In Paragraph 1, The above oxygen supply line is, A axial section positioned behind a pre-set constriction point and formed such that the cross-sectional area of ​​the internal passage gradually decreases; and An expansion section connected to the above-mentioned contraction section and positioned in front of the above-mentioned constriction point, formed such that the cross-sectional area of ​​the internal passage gradually increases; including, Integrated injection device for melting furnaces.

4. In Paragraph 1, At the front section of the main body above, A mixing space is formed in which oxygen flowing through the oxygen supply line and fuel or outside air flowing through the composite supply line are discharged and mixed. Integrated injection device for melting furnaces.

5. In Paragraph 4, The front-to-back length of the above-mentioned spray nozzle is formed to be longer than the front-to-back length of the above-mentioned mixing space, Integrated injection device for melting furnaces.

6. In Paragraph 1, The above composite supply line is formed to wrap around the circumference of the above oxygen supply line, Integrated injection device for melting furnaces.

7. In Paragraph 6, The above-mentioned complex supply line is, A switching valve including a switching valve that selectively controls the supply and cutoff of fuel or outside air, Integrated injection device for melting furnaces.

8. In Paragraph 1, The above jet supply line is provided at the connection point between the main body and the injection nozzle, Integrated injection device for melting furnaces.

9. In Paragraph 1, The above jet supply lines are arranged in multiple numbers along the circumference of the main body and the injection nozzle. Integrated injection device for melting furnaces.

10. Step (a) in which the device control unit sets the operating mode of the integrated injection device for the melting furnace to either the burner mode or the lance mode; Step (b1), in which, if the operating mode set in step (a) above is a burner mode, the device control unit controls oxygen to be supplied through the oxygen supply line of the integrated injection device for the melting furnace and controls fuel to be supplied through the composite supply line so that the supply fluid is injected into the furnace side of the melting furnace through the injection nozzle; and Step (b2), in which, if the operating mode set in step (a) above is a lance mode, the device control unit controls oxygen to be supplied through the oxygen supply line of the integrated injection device for the melting furnace and controls fuel supply through the composite supply line to be blocked so that the supply fluid is injected into the furnace side of the melting furnace through the injection nozzle; including, Control method for an integrated injection device for a melting furnace.

11. In Paragraph 10, The above step (b1) is, Step (b1-1) in which the above device control unit controls the oxygen flow rate flowing through the oxygen supply line so that it is supplied to the injection nozzle side; Step (b1-2) in which the device control unit controls a switching valve provided in the complex supply line to block the supply of outside air; (b1-3) step in which the device control unit controls the flow rate of fuel flowing through the composite supply line so that it is supplied to the injection nozzle side; and Step (b1-4) in which the above device control unit selectively supplies a jet for deflection control through the jet supply line of the integrated injection device for the melting furnace to control the injection direction of the supply fluid; including, Control method for an integrated injection device for a melting furnace.

12. In Paragraph 11, The above step (b1-3) is, The above device control unit controls the flow rate of fuel flowing through the above composite supply line to be 25% or less of the flow rate of oxygen flowing through the above oxygen supply line, Control method for an integrated injection device for a melting furnace.

13. In Paragraph 11, The above (b1-4) steps are, The above device control unit controls the flow rate of the deflection control jet flowing through the jet supply line to be 13% or less of the oxygen flow rate flowing through the oxygen supply line, Control method for an integrated injection device for a melting furnace.

14. In Paragraph 10, The above step (b2) is, Step (b2-1) in which the above device control unit controls the oxygen flow rate flowing through the oxygen supply line so that it is supplied to the injection nozzle side; (b2-2) step in which the above device control unit controls a switching valve provided in the above complex supply line to cut off the supply of fuel; and Step (b2-3) in which the device control unit controls a switching valve provided in the composite supply line to block the supply of outside air, or controls the flow rate of outside air flowing through the composite supply line to supply it to the injection nozzle side, thereby controlling the injection distance of the supply fluid; including, Control method for an integrated injection device for a melting furnace.

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