Height profile creation device for metal raw material, control device for electric furnace facility, and electric furnace facility

Abstract

Provided in an electric furnace facility comprising: a melting chamber for melting a metal raw material; and an electrode inserted into the melting chamber from above. In the electric furnace facility, the metal raw material charged in the melting chamber is dissolved by an arc generated from the electrode. Also provided is a height profile creation device for a metal raw material, said device being characterized by comprising: a 2D or higher range-finding radar provided at a position where a top surface position of the metal raw material in the electric furnace facility can be measured; and a computation unit that calculates the height profile of the metal raw material on the basis of data on the top surface position measured by the range-finding radar.

Description

Metal raw material height profile creating device, electric furnace equipment control device, and electric furnace equipment

[0001] The present invention relates to a device for measuring the height of metal raw materials in a melting chamber or a preheating chamber in an electric furnace facility that melts metal raw materials using an arc, a device for controlling the electric furnace facility based on the results of this measurement, and the electric furnace facility.

[0002] Patent Literature 1 discloses a method for observing the melting state of a metal raw material using an industrial television (ITV) camera to determine burn-through of the metal raw material in an electric furnace facility that melts the metal raw material using an arc. Patent Literature 2 discloses a method for measuring the level (height) of the metal raw material charged in a preheating chamber of the electric furnace facility using a microwave level meter or a microwave switch.

[0003] Japanese Patent Laid-Open No. 7-286218 Japanese Patent Laid-Open No. 2004-250724

[0004] Flames, fumes, and dust are constantly generated in the melting chamber and preheating chamber of an electric furnace during the melting of metal raw materials. For this reason, optical observation using visible or infrared light, such as observation using an ITV camera, can sometimes make it difficult to grasp the melting status of the metal raw materials because the visible or infrared light is blocked by the flames, fumes, dust, etc.

[0005] On the other hand, microwave level meters and microwave switches can receive good reflected waves and perform highly accurate measurements when the measurement object is molten metal, slag, metal raw materials with uniform particle size, etc. However, when the measurement object is, for example, iron scrap, which has a variety of shapes and surface configurations, the reflected waves may be reflected multiple times, which can lead to false detection, or the strength of the reflected waves may be weakened, making it difficult to perform stable, highly accurate measurements.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to create a height profile of a metal raw material with high accuracy using a simple configuration.

[0007] The main invention for achieving the above object is an apparatus for creating a height profile of a metal raw material, which is an electric furnace equipment having a melting chamber for melting a metal raw material and an electrode inserted into the melting chamber from above, and in which the metal raw material charged into the melting chamber is melted by an arc generated from the electrode, the apparatus comprising: a two- or more dimensional ranging radar provided in a position where it can measure a measurement object within the electric furnace equipment; and a calculation unit that calculates a height profile of the metal raw material based on data of the measurement object measured by the ranging radar.

[0008] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0009] According to the present invention, a height profile of a metal raw material can be created with high accuracy using a simple configuration.

[0010] 1 is an explanatory diagram of an electric furnace facility 100 in which a height profile creation device 20 according to a first embodiment of the present invention is installed; FIG. 2 is a detailed explanatory diagram of a water-cooled lance 31 equipped with a ranging radar 30 that measures the inside of a melting chamber 18; FIG. 3 is a diagram showing an example of measurement results by the ranging radar 30 in a preheating chamber 19; FIG. 4 is a flow chart showing an example of a control procedure for the electric furnace facility 100 according to the present invention; and FIG. 5 is an explanatory diagram of an electric furnace facility 100A in which a height profile creation device 20A according to a second embodiment of the present invention is installed.

[0011] At least the following points will become clear from the description and drawings to be described later.

[0012] A height profile creation device for metal raw materials has been revealed, which is characterized in that, in an electric furnace equipment comprising a melting chamber for melting metal raw materials and an electrode inserted into the melting chamber from above, the metal raw materials loaded into the melting chamber are melted by an arc generated from the electrode, the device comprises: a two-dimensional or higher ranging radar installed in a position where it can measure a measurement object within the electric furnace equipment; and a calculation unit that calculates a height profile of the metal raw materials based on data of the measurement object measured by the ranging radar.

[0013] According to such a height profile creating device for metal raw materials, a height profile for metal raw materials can be created with high accuracy using a simple configuration.

[0014] In such a metal raw material height profile creation device, it is desirable that the ranging radar is a frequency continuous modulation radar, and the calculation unit is configured to calculate the height profile of the metal raw material based on data obtained by removing measurement data of at least one of dust and splash from data of the measurement object using velocity information of the measurement object.

[0015] According to such a height profile creating device for metal raw materials, a height profile for metal raw materials can be created with high accuracy using a simple configuration.

[0016] In such a metal raw material height profile creation device, it is desirable that the ranging radar be provided inside the upper part of the melting chamber and be configured to be able to measure the measurement object inside the melting chamber.

[0017] According to such a height profile creating device for metal raw materials, a height profile for metal raw materials can be created with high accuracy using a simple configuration.

[0018] In such a height profile creation device for metal raw materials, it is desirable that the electric furnace equipment further comprises a preheating chamber for preheating the metal raw materials, which is directly connected to the melting chamber, and the ranging radar is provided at the top inside of the preheating chamber, and is configured to be able to measure the measurement object inside the preheating chamber.

[0019] According to such a height profile creating device for metal raw materials, a height profile for metal raw materials can be created with high accuracy using a simple configuration.

[0020] In such a height profile creation device for metal raw materials, it is desirable that the electric furnace equipment further comprises a preheating chamber for preheating the metal raw materials, which is directly connected to the melting chamber, and that the ranging radar is provided on the inside upper part of the melting chamber and the inside upper part of the preheating chamber, and is configured to be able to measure the measurement object inside the melting chamber and the preheating chamber.

[0021] According to such a height profile creating device for metal raw materials, a height profile for metal raw materials can be created with high accuracy using a simple configuration.

[0022] A control device for electric furnace equipment has been revealed, which is characterized by comprising the above-mentioned metal raw material height profile creation device and a control unit configured to control at least one of the timing and amount of metal raw material supply to the melting chamber and the amount of energy input to the melting chamber based on the height profile of the metal raw material in the melting chamber created by the metal raw material height profile creation device.

[0023] According to such a control device for an electric furnace facility, it is possible to improve the thermal efficiency of the electric furnace facility and increase productivity.

[0024] A control device for electric furnace equipment has been revealed, which is characterized by comprising the above-mentioned metal raw material height profile creation device and a control unit configured to control the timing and amount of supply of the metal raw material from the preheating chamber to the melting chamber based on the height profile of the metal raw material in the preheating chamber created by the metal raw material height profile creation device.

[0025] According to such a control device for an electric furnace facility, it is possible to improve the thermal efficiency of the electric furnace facility and increase productivity.

[0026] A control device for electric furnace equipment has been revealed, which is characterized by comprising the above-mentioned metal raw material height profile creation device and a control unit configured to control at least one of the amount of energy input to the melting chamber and the timing and amount of supply of the metal raw material from the preheating chamber to the melting chamber based on a first profile, which is a height profile of the metal raw material in the melting chamber, created by the metal raw material height profile creation device, and a second profile, which is a height profile of the metal raw material in the preheating chamber.

[0027] According to such a control device for an electric furnace facility, it is possible to improve the thermal efficiency of the electric furnace facility and increase productivity.

[0028] Furthermore, an electric furnace system is provided which includes a melting chamber for melting metal raw materials and electrodes inserted into the melting chamber from above, and which melts the metal raw materials charged into the melting chamber by an arc generated from the electrodes, and which is characterized by including the above-mentioned control device.

[0029] Such an electric furnace facility can provide an electric furnace facility with high thermal efficiency and productivity.

[0030] 1 is an explanatory diagram of an electric furnace facility 100 in which a height profile creation device 20 according to a first embodiment of the present invention is installed. FIG. 2 is a detailed explanatory diagram of a water-cooled lance 31 equipped with a ranging radar 30 that measures the inside of a melting chamber 18.

[0031] <<Definition of Directions, etc.>> Hereinafter, as shown in Figures 1 and 2, the vertical direction will be referred to as the "up-down direction," the vertically upward direction will simply be referred to as the "upward direction," and the vertically downward direction will simply be referred to as the "downward direction." The "up-down direction" may also be referred to as the "height direction." The horizontal direction may also be referred to as the "lateral direction" or "width direction."

[0032] The above definitions of directions and the like are common to other embodiments in this specification unless otherwise specified.

[0033] <<Outline of Electric Furnace Equipment 100>> The electric furnace equipment 100 is equipment that melts a metal raw material 1 in an electric furnace. In this embodiment, the metal raw material 1 melted in the electric furnace equipment 100 is, for example, iron scrap. However, the metal raw material 1 melted in the electric furnace equipment 100 is not limited to iron scrap, and may be reduced iron (DRI), hot briquetted iron (HBI), cold pig iron (mold pig iron), aluminum, or the like. In the following description, the molten metal obtained by melting the metal raw material 1 may be referred to as "molten metal."

[0034] In the arc furnace used in the electric furnace equipment 100, an electric current is applied to electrodes 14 (described below) arranged in the electric furnace equipment 100, thereby generating an arc 4 from the electrodes 14, as shown in FIG. 1 . The metal raw material 1 is then heated and melted by the heat (arc heat) of the arc 4 generated from the electrodes 14, producing molten metal. The metal raw material 1 can also be melted by being immersed in molten metal 2.

[0035] The electric furnace used in the electric furnace facility 100 of this embodiment is a continuous charging electric furnace. However, the electric furnace used in the electric furnace facility 100 is not limited to a continuous charging electric furnace, and may be a batch charging electric furnace of the second embodiment described below, or may be of another charging type. Details of continuous charging electric furnaces and batch charging electric furnaces will be described later.

[0036] The electric furnace facility 100 includes a melting facility 110 and a skip 15 .

[0037] <Melting equipment 110> The melting equipment 110 is the main equipment of an electric furnace into which a metal raw material 1 is charged and which melts the metal raw material 1 using arc heat. As shown in FIG. 1 , the metal raw material 1 is heated and melted in the melting equipment 110 to form molten metal 2 and slag 3. The molten metal 2 is refined, such as by decarburization, if necessary, and then tapped from a tapping port (not shown). The slag 3 is removed prior to the tapping of the molten metal 2. Note that, of the metal raw material 1 charged into the melting equipment 110, components that have not yet been melted remain in the melting equipment 110 as unmelted metal raw material 1, as shown in FIG. 1 .

[0038] The melting equipment 110 includes a melting chamber 18 , a preheating chamber 19 , an electrode 14 , a power supply device 23 , and an extrusion device 21 .

[0039] Melting Chamber 18 The melting chamber 18 is a portion of the melting equipment 110 where the metal raw material 1 is melted. As shown in FIG. 1 , the melting chamber 18 is directly connected to the preheating chamber 19. The metal raw material 1 preheated in the preheating chamber 19 is pushed into the melting chamber 18 by a pusher 21. A furnace lid 16 is provided above the melting chamber 18. The furnace lid 16 has an opening for inserting the electrode 14 and an opening for inserting a water-cooled lance 31 equipped with a ranging radar 30 (described below). The furnace lid 16 has a shutter 22 (not shown in FIG. 1 ; see FIG. 2 ) for opening and closing the opening for inserting the water-cooled lance 31 (described below). The shutter 22 can be moved laterally by a drive unit (not shown). This allows the opening for inserting the water-cooled lance 31 to be opened and closed. When the opening formed in the furnace lid 16 is in an open state, the water-cooled lance 31 (ranging radar 30) is inserted through the opening and positioned to measure the measurement target inside the melting chamber 18.

[0040] The outer shell of the melting chamber 18 is made of iron and has a lining that forms the bottom portion, which is the reservoir for the molten metal 2. The lining is made of a refractory material and can store the molten metal 2 obtained by melting the metal raw material 1. The upper portion of the melting chamber 18 that does not come into contact with the molten metal may be configured with a water-cooled panel having a water-cooling structure (not shown). The water-cooled panel may be configured, for example, with multiple block-shaped water-cooled boxes.

[0041] In addition to the above-described configuration, the melting chamber 18 may further include at least one of a burner, an oxygen gas injection lance, and a carbonaceous material injection lance. The burner, the oxygen gas injection lance, and the carbonaceous material injection lance may obliquely penetrate the outer shell of the melting chamber 18 and be movable obliquely within the melting chamber 18. The burner promotes melting of the metal raw material 1 by the combustion heat of the fuel gas. The oxygen gas injection lance injects oxygen gas into the melting chamber 18 for decarburization. The carbonaceous material injection lance injects a carbonaceous material such as coke, char, coal, charcoal, or graphite into the melting chamber 18 to promote melting of the metal raw material 1 by the combustion heat and to add carburization to the molten metal 2. In this case, air, nitrogen gas, or the like is used as a carrier gas for the carbonaceous material.

[0042] Preheating Chamber 19 The preheating chamber 19 is a portion of the melting equipment 110 that preheats the metal raw material 1 with high-temperature exhaust gas before the metal raw material 1 is melted in the melting chamber 18. As shown in FIG. 1 , the preheating chamber 19 is directly connected to the melting chamber 18, and the metal raw material 1 is charged into the preheating chamber 19 from the skip 15. A lid 17 is provided on the top of the preheating chamber 19. The lid 17 can be moved up and down and / or rotated by a drive device (not shown). This allows the top of the preheating chamber 19 to be set in an open or closed state. When the top of the preheating chamber 19 is open (i.e., in the state shown in FIG. 1 ), the metal raw material 1 can be charged into the preheating chamber 19 from the skip 15.

[0043] An exhaust gas duct (not shown) is connected to the top of the preheating chamber 19 for discharging exhaust gas generated in the melting chamber 18 to the outside. As a result, the exhaust gas generated in the melting chamber 18 preheats the metal raw material 1 in the preheating chamber 19 and then is discharged from the exhaust gas duct. At this time, by keeping the top of the preheating chamber 19 in a closed state, the heat of the exhaust gas is not dissipated from above the preheating chamber 19, and the metal raw material 1 can be preheated efficiently.

[0044] Electrode 14 The electrode 14 is an electrode (arc electrode) that generates the arc 4. The electrode 14 is inserted into the melting chamber 18 from above the furnace lid 16 through an opening formed in the furnace lid 16. The electrode 14 is a graphite electrode. Since the electric furnace of this embodiment is a DC arc furnace, one electrode 14 is shown in FIG. 1 . In the case of a DC arc furnace such as this embodiment, one electrode 14 is disposed in the melting chamber 18, and another electrode (not shown) is disposed at the bottom of the melting chamber 18. However, the present invention is applicable to both AC arc furnaces and DC arc furnaces. When the electric furnace used in the electric furnace equipment 100 is a three-phase AC arc furnace, three electrodes 14 are inserted into the melting chamber 18.

[0045] In this embodiment, the electrode 14 is energized by applying a DC voltage from the power supply 23. This generates an arc between the electrode 14 and the metal raw material 1 or the molten metal 2 (slag 3), and the metal raw material 1 can be heated and melted by the arc heat (i.e., the molten metal 2 is produced).

[0046] Power Supply Device 23 The power supply device 23 is a device for applying a voltage to the electrodes 14. As described above, the electric furnace used in the electric furnace equipment 100 of this embodiment is a DC arc furnace, and the power supply device 23 applies a DC voltage to the electrodes 14. The power supply device 23 has an electric quantity measuring device that measures the voltage and current applied to the electrodes 14. The electric quantity measuring device includes a voltmeter and an ammeter. Since the power supply device 23 has an electric quantity measuring device, the power supply device 23 is configured to be able to measure the values ​​of the voltage and current applied to the electrodes 14, and can output the measured voltage, current, electric energy, and other electric power quantities to an external device (here, the control device 10 described below).

[0047] Extrusion Device 21 The extrusion device 21 is a device for extruding the metal raw material 1 from the preheating chamber 19 into the melting chamber 18. As shown in FIG. 1 , the extrusion device 21 is disposed at the bottom of the preheating chamber 19. The metal raw material 1 is preheated in the preheating chamber 19 until it is extruded into the melting chamber 18 by the extrusion device 21.

[0048] Others Furthermore, the melting equipment 110 is provided with a tilting mechanism (not shown) that tilts the melting equipment 110 when pouring the molten metal 2 or discharging the slag 3 .

[0049] <Skip 15> The skip 15 is a device for transporting the metal raw material 1 to the upper part of the preheating chamber 19 and charging it into the melting equipment 110 (specifically, into the preheating chamber 19). As shown in Fig. 1, the metal raw material 1 is charged into the preheating chamber 19 from the upper part when the upper part of the preheating chamber 19 is open (the lid 17 is open). Specifically, as shown in Fig. 1, the skip 15 is tilted, and the metal raw material 1 in the skip 15 is charged into the preheating chamber 19. In Fig. 1, the position of the tilted skip 15 is indicated by a dashed line.

[0050] <<Height Profile Creation Device 20 >> As shown in FIG. 1 , the electric furnace facility 100 of this embodiment includes a control device 10 having a height profile creation device 20 .

[0051] The height profile creation device 20 is a device that creates a height profile of the metal raw material 1 in the electric furnace facility 100. The height profile creation device 20 in this embodiment has a simple configuration including a ranging radar 30, which will be described later, and can accurately measure the volume of the empty space in the melting chamber 18 and the preheating chamber 19, and can accurately create a height profile of the metal raw material 1.

[0052] As described above, the electric furnace used in the electric furnace facility 100 of this embodiment is a continuous charging electric furnace. In a continuous charging electric furnace, the metal raw material 1 is continuously charged into the melting chamber 18 via the preheating chamber 19. First, the metal raw material 1 is charged into the preheating chamber 19 from the skip 15. In FIG. 1 , the upper surface of the metal raw material 1 at this time is indicated by a dashed line. After the metal raw material 1 is charged, the lid 17 on the top of the preheating chamber 19 is closed, and the metal raw material 1 is melted, and the metal raw material 1 in the preheating chamber 19 is preheated by exhaust gas generated in the melting chamber 18.

[0053] As the melting of the metal raw material 1 in the melting chamber 18 progresses, the metal raw material 1 is periodically pushed out from the preheating chamber 19 into the melting chamber 18 by a pusher 21 disposed at the bottom of the preheating chamber 19. The metal raw material 1 in the preheating chamber 19 moves downward by the amount of metal raw material 1 pushed out into the melting chamber 18. In Figure 1, the position of the upper surface of the metal raw material 1 at this time is indicated by a solid line. When the space at the top of the preheating chamber 19 expands to allow additional metal raw material 1 to be charged, the lid 17 at the top of the preheating chamber 19 is opened, and additional metal raw material 1 is charged into the preheating chamber 19 from the skip 15.

[0054] Here, in order to improve the efficiency of preheating the metal raw material 1 in the preheating chamber 19, it is desirable to charge the additional metal raw material 1 as soon as possible once the space available for charging the additional metal raw material 1 has expanded. In other words, it is desirable to determine as accurately as possible the time when the additional metal raw material 1 can be charged. If the additional metal raw material 1 is charged too early, the metal raw material 1 may overflow from the top of the preheating chamber 19, making it impossible to close the lid 17 on the top of the preheating chamber 19, which may actually increase heat loss within the melting equipment 110. Furthermore, dealing with the inability to close the lid 17 may increase the operator's working time.

[0055] For this reason, in the electric furnace equipment 100, it is important to accurately grasp the volume of the empty space in the preheating chamber 19. The volume of the empty space in the preheating chamber 19 can be estimated to some extent from height information of the metal raw material 1 at one point in the preheating chamber 19, but if a height profile of the metal raw material 1 can be created with high accuracy, this volume can be calculated with even higher accuracy. Here, the "height profile of the metal raw material 1" refers to height position information of multiple points on the top surface of the metal raw material 1 in the electric furnace equipment 100.

[0056] Meanwhile, flames, fumes, and dust are constantly generated in the melting chamber 18 and preheating chamber 19 of the electric furnace equipment 100 while the metal raw material 1 is being melted. Visible light and infrared light are blocked by the flames, fumes, and dust, so it is difficult to grasp the melting status of the metal raw material 1, i.e., the volume of the empty space in the preheating chamber 19, by optical observation using an ITV camera. Furthermore, even with laser measurement using LiDAR (Light Detection and Ranging) or the like, accurate measurement may not be possible because the laser light is blocked by the flames, fumes, and dust.

[0057] Furthermore, microwave level meters and microwave switches are only slightly affected by small fumes, such as flames, fumes, splashes (droplets of molten metal), and dust generated in the melting chamber and preheating chamber, but are significantly affected by large splashes and dust, which can cause false detections and result in noise in the measurement results. Furthermore, microwave level meters and microwave switches can only perform one-dimensional measurements, making it difficult to create a height profile of the metal raw material using a single microwave level meter or microwave switch. This requires the installation of multiple microwave level meters or microwave switches, which creates installation constraints and high costs.

[0058] First of all, the shape of the surface (top surface) of the metal raw material 1 in the melting chamber 18 or the preheating chamber 19 is not flat in the horizontal direction but varies, and typically includes, for example, unevenness and slanted portions. For this reason, when creating a height profile of the metal raw material 1, microwave level meters and microwave switches that can only perform one-dimensional measurements cannot obtain sufficiently useful measurement results due to the effects of multiple reflections, and measurements cannot be made with high accuracy. Therefore, when creating a height profile of the metal raw material 1, multi-point measurements in two or more dimensions are performed instead of one-dimensional measurements. This allows for more accurate height profile information of the metal raw material 1 to be obtained.

[0059] Here, one-dimensional measurement means measuring the distance to one point on the measurement object, two-dimensional measurement means measuring the distance to multiple points on the line of the measurement object (on the intersection between the plane including the position (point) of the ranging radar 30 and the surface of the measurement object), and three-dimensional measurement means measuring the distance to multiple points on the surface of the measurement object.

[0060] <Range measuring radar 30> The range measuring radar 30 is a multipoint range measuring radar capable of multipoint measurement in two or more dimensions. The range measuring radar 30 of this embodiment uses a millimeter wave radar. This allows it to penetrate flames and fumes and achieve a distance accuracy of approximately 200 mm or less. In addition, it is possible to minimize the area (widthwise area) of the antenna portion (range measuring radar 30 shown in FIG. 2) exposed to an environment with a high temperature flame or a lot of fumes.

[0061] Specifically, the ranging radar 30 is, for example, a millimeter-wave radar in the 79 GHz band. In this embodiment, the antenna area of ​​the ranging radar 30 is 50 mm square, and a MIMO (Multi-Input Multi-Output) FMCW (Frequency Modulated Continuous Wave) radar is used to obtain high azimuth resolution without using a mechanical drive device. However, any radar capable of multipoint measurement in two or more dimensions can be used, and for example, a radar equipped with a mechanical drive device can also be used. In this embodiment, the ranging radar 30 is housed in a water-cooled dustproof case (not shown) to protect it from high-temperature environments. As shown in FIG. 2 , the cap portion 33 of the ranging radar 30 is made of ceramics or heat-resistant glass, which is permeable to radio waves and easily removes deposits due to splashes generated in the melting chamber 18. While the distance measuring radar 30 (water-cooled lance 31) is positioned outside the melting chamber 18 or the preheating chamber 19, the cap portion 33 is cleaned by a mechanism (not shown) for removing any deposits, thereby preventing the deposits from blocking radio waves.

[0062] The ranging radar 30 is disposed above the melting equipment 110, at a position where it can measure the measurement target within the electric furnace equipment 100. Specifically, the ranging radar 30 (water-cooled lance 31) is provided above the melting chamber 18, on the furnace lid 16 as shown in FIG. 1 . This allows the ranging radar 30 to measure a wide range of the measurement target within the melting chamber 18. The ranging radar 30 is installed midway between the center of the melting chamber 18 and the preheating chamber 19 in the horizontal direction, and measures the position of the top surface of the metal raw material 1. In addition, two ranging radars 30 are also provided above the preheating chamber 19, near the lid 17 of the preheating chamber 19 as shown in FIG. 1 . This allows the ranging radar 30 to measure a wide range of the measurement target within the preheating chamber 19.

[0063] The number and locations of the distance measuring radars 30 are not limited to the configuration shown in Fig. 1. For example, the height profile creation device 20 may only have a distance measuring radar 30 installed in the melting chamber 18, or only have a distance measuring radar 30 installed in the preheating chamber 19. The distance measuring radar 30 may be installed in a position where it can measure the measurement target within the electric furnace facility 100.

[0064] In order to prevent deposits due to splashes generated in the melting chamber 18 from adhering to the tip of the water-cooled lance 31 equipped with the ranging radar 30, the water-cooled lance 31 (ranging radar 30) provided in the melting chamber 18 may be periodically inserted into the melting chamber 18 for a short period of time to perform measurements. The water-cooled lance 31 (ranging radar 30) may be located outside the melting chamber 18, specifically above the furnace lid 16 of the melting chamber 18, while measurements are not being taken. Furthermore, the water-cooled lance 31 (ranging radar 30) measures the position of the top surface of the metal raw material 1 multiple times while changing its position in the vertical direction, thereby improving the accuracy of the height profile of the metal raw material 1 to be created.

[0065] 2, the ranging radar 30 of this embodiment is housed in a water-cooled lance 31 that is movable in the vertical direction. The water-cooled lance 31 is attached to a location near the top of the melting chamber 18 (specifically, an opening formed in the furnace lid 16). The water-cooled lance 31 circulates cooling water through a cooling water flow path 32 provided inside, thereby protecting the ranging radar 30 even in the high-temperature melting chamber 18.

[0066] The ranging radar 30 emits radio waves toward the measurement target and measures the distance to multiple points from the reflected waves by azimuth resolution. The ranging radar 30 is a frequency-continuous modulation radar, and can measure not only the distance to the measurement target but also the speed of the measurement target. This makes it possible to measure not only the stationary metal raw material 1 but also floating dust and flying splash. In other words, the measurement target of the ranging radar 30 is not limited to the metal raw material 1 but also includes dust, splash, etc., and is an object within the electric furnace facility 100.

[0067] As described above, the surface shapes of the metal raw material 1 in the melting chamber 18 and the preheating chamber 19 vary. Therefore, the measurement results of the ranging radar 30, which is a multipoint ranging radar, are output as a point cloud with multiple peaks in areas where reflection is strong. Furthermore, for floating dust particles that are too large for millimeter waves to penetrate, the Doppler radar function of the ranging radar 30, which is a multipoint ranging radar, can be used to detect velocity components, and the obtained point cloud can be processed as a time average to separate the floating dust particles from the stationary metal raw material 1.

[0068] Furthermore, when the metal raw material 1 is pushed out from the preheating chamber 19 into the melting chamber 18 by the pushing device 21, the upper surface position of the metal raw material 1 in the preheating chamber 19 moves downward, so that it is possible to distinguish between reflection from the upper surface position of the metal raw material 1 and reflection from the inner wall of the preheating chamber 19.

[0069] <Acquisition unit 11> The acquisition unit 11 is a part that acquires data of the measurement target measured by the ranging radar 30. The acquisition unit 11 may also acquire data from various devices of the electric furnace equipment 100 (for example, the above-mentioned power supply device 23, skip 15, push-out device 21, etc.). However, if the calculation unit 12 has the function of the acquisition unit 11, the acquisition unit 11 may be omitted.

[0070] <Calculation Unit 12> The calculation unit 12 is a part that calculates the height profile of the metal raw material 1 based on the data acquired by the acquisition unit 11 (i.e., data of the measurement target measured by the ranging radar 30). An example of a procedure for calculating the height profile of the metal raw material 1 will be described later in the description of an example of a control procedure.

[0071] <<Controller 10 Equipped with Height Profile Creation Device 20>> The controller 10 controls the electric furnace facility 100 based on the height profile of the raw metal material 1 created by the height profile creation device 20, thereby improving the thermal efficiency of the electric furnace facility 100 and increasing productivity. Specifically, it becomes possible to determine the appropriate time to charge additional raw metal material 1. Furthermore, it is possible to evaluate the progress and uniformity of the melting state of the raw metal material 1 in the melting chamber 18, and optimize the control of the power and combustion energy input to the electric furnace facility 100.

[0072] The control device 10 equipped with such a height profile creating device 20 will be described in detail below.

[0073] The control device 10 is a device for controlling the electric furnace facility 100 (specifically, various devices of the electric furnace facility 100, such as the power supply device 23, skip 15, push-out device 21, etc.). The control device 10 may have a function of displaying the results of various processes in the control device 10 (for example, the height profile of the metal raw material 1) on the display device of the operator terminal 90 shown in FIG. 1. However, the control device 10 may also display the results of various processes in the control device 10 on a device other than the display device of the operator terminal 90.

[0074] The control device 10 has a ranging radar 30, an acquisition unit 11, a calculation unit 12, and a control unit 13. The ranging radar 30, the acquisition unit 11, and the calculation unit 12 constitute a height profile creation device 20 for metal raw material 1. However, as will be described later, if the calculation unit 12 has the function of the acquisition unit 11 and the control device 10 does not have the acquisition unit 11, the ranging radar 30 and the calculation unit 12 constitute the height profile creation device 20 for metal raw material 1.

[0075] <Control Unit 13> The control unit 13 is a component that transmits control commands to the electric furnace equipment 100 based on the height profile of the metal raw material 1 created by the height profile creation device 20 for creating a height profile of the metal raw material 1. Here, the height profile of the metal raw material 1 in the present invention is at least one of the height profile of the metal raw material 1 in the melting chamber 18 and the height profile of the metal raw material 1 in the preheating chamber 19. The height profile creation device 20 of this embodiment is configured such that the ranging radars 30 are provided at the upper inside of the melting chamber 18 and the upper inside of the preheating chamber 19 and are capable of measuring the measurement targets in the melting chamber 18 and the preheating chamber 19, and therefore is able to create both the height profile of the metal raw material 1 in the melting chamber 18 and the height profile of the metal raw material 1 in the preheating chamber 19.

[0076] The control unit 13 controls at least one of the timing and amount of supply of the metal raw material 1 to the melting chamber 18 and the amount of energy input to the melting chamber 18 based on the height profile of the metal raw material 1 in the melting chamber 18. The control unit 13 can, for example, send a control command to the skip 15 to control the timing and amount of supply of the metal raw material 1 to the melting chamber 18. The control unit 13 can also, for example, send a control command to the power supply device 23 to control the amount of energy input to the melting chamber 18.

[0077] Furthermore, the control unit 13 controls the timing and amount of metal raw material 1 to be supplied into the melting chamber 18 and the timing and amount of metal raw material 1 to be supplied from the preheating chamber 19 to the melting chamber 18 based on the height profile of the metal raw material 1 in the preheating chamber 19. The control unit 13 can send a control command to the extrusion device 21 to control the timing and amount of metal raw material 1 to be supplied from the preheating chamber 19 to the melting chamber 18, for example.

[0078] Furthermore, the control unit 13 can control at least one of the timing and amount of supply of the metal raw material 1 to the melting chamber 18, the amount of energy input to the melting chamber 18, and the timing and amount of supply of the metal raw material 1 from the preheating chamber 19 to the melting chamber 18, based on the height profile of the metal raw material 1 in the melting chamber 18 (hereinafter sometimes referred to as the "first profile") and the height profile of the metal raw material 1 in the preheating chamber 19 (hereinafter sometimes referred to as the "second profile").

[0079] <Configuration of control device 10> The control device 10 is able to execute various processes in the control device 10 through cooperation of various hardware and software (not shown). The control device 10 is a computer such as a server, and includes a CPU, memory, storage device, etc. The storage device stores programs related to the various processes executed by the control device 10 and various data.

[0080] For example, the above-mentioned calculation unit 12 reads out a program stored in the storage device into memory and executes it, thereby realizing various processes in the calculation unit 12 (such as the process of creating a height profile of the metal raw material 1 and the control process of the electric furnace equipment 100, which will be described later). Note that the control device 10 may include multiple computers. The various processes in the control device 10 may be executed by the multiple computers working together via a network.

[0081] 3 is a diagram showing an example of the measurement results by the ranging radar 30 in the preheating chamber 19. The depth on the vertical axis is the depth with the installation position of the ranging radar 30 (the bottom surface of the ranging radar 30) as the reference point (zero point).

[0082] The measurement results shown in FIG. 3 output point clouds A and B. Point cloud A is a point cloud close to the metal raw material 1 and can be evaluated as a point cloud located at the top surface position for calculating the height profile of the metal raw material 1. Point cloud B is a point cloud far from the metal raw material 1 and can be evaluated as a point cloud resulting from reflected waves from floating dust. Point cloud B can be selected and removed by the calculation unit 12 because its velocity is not zero (i.e., it is moving) and its position changes depending on the measurement time. The solid line indicated by the symbol W represents the side wall of the preheating chamber 19. The calculation unit 12 calculates the volume of the empty space in the preheating chamber 19 from the measurement results obtained by the ranging radar 30, and the control unit 13 outputs a charging command to the skip 15 when the empty space in the preheating chamber 19 becomes larger than the volume of the additional metal raw material 1 to be charged.

[0083] FIG. 4 is a flow chart showing an example of a procedure for controlling the electric furnace equipment 100 of the present invention based on the height profile (second profile) of the metal raw material 1 in the preheating chamber 19.

[0084] First, the acquisition unit 11 acquires the measurement results from the distance measuring radar 30 provided in the preheating chamber 19 (S001).

[0085] In the control device 10, when the extrusion device 21 is extruding the metal raw material 1, i.e., when the extrusion device 21 is operating ("YES" in S002), the calculation unit 12 selects data having a downward velocity by selecting data having a velocity equal to or greater than a predetermined value (S003). Furthermore, by comparing and correcting the data (S004), a height profile relating to the position of the upper surface of the metal raw material 1 can be calculated.

[0086] In the control device 10, when the extrusion device 21 is not extruding the metal raw material 1, i.e., when the extrusion device 21 is stopped ("NO" in S002), the calculation unit 12 selects data where the speed is equal to or less than a predetermined value by removing data where the speed exceeds a threshold (S005). Furthermore, false signals of large floating dust particles or splashes are removed by averaging the data for each mesh over time (S006 and S007). This makes it possible to calculate a height profile related to the upper surface position of the stationary metal raw material 1. The control unit 13 displays the height profile of the metal raw material 1 on the display device of the operator terminal 90 (S008).

[0087] The calculation unit 12 calculates the free space in the preheating chamber 19 (i.e., the volume of the space above the preheating chamber 19) from the height profile relating to the upper surface position of the metal raw material 1 (S009), and the control unit 13 compares this with the volume of the metal raw material 1 in the skip. If the free space in the preheating chamber 19 is larger than the volume of the metal raw material 1 in the skip, the control unit 13 determines that the metal raw material 1 can be charged ("YES" in S010) and sends a charging command to the skip 15 (S011). If the free space in the preheating chamber 19 is smaller than the volume of the metal raw material 1 in the skip, the control unit 13 determines that the metal raw material 1 cannot be charged ("NO" in S010) and waits until it can be charged.

[0088] The above control procedure is an example of a procedure for controlling the electric furnace equipment 100 based on the height profile of the raw material metal 1 in the preheating chamber 19. An example of a procedure for controlling the electric furnace equipment 100 based on the height profile (first profile) of the raw material metal 1 in the melting chamber 18 will now be briefly described. First, the calculation unit 12 calculates a height profile relating to the position of the upper surface of the raw material metal 1 in the melting chamber 18. False signals such as splashes in the melting chamber 18 can be eliminated by selecting data whose velocity is below a predetermined value and removing data whose velocity significantly deviates from all data, as in steps S005 to S007 above. This allows for the creation of an accurate height profile of the raw material metal 1 in the melting chamber 18. Based on this height profile, the control unit 13 sends an extrusion command to the extrusion device 21 when the volume of the raw material metal 1 remaining in the melting chamber 18 falls below a threshold. Furthermore, if the extrusion amount is too large (if the volume of the raw material metal 1 remaining in the melting chamber 18 exceeds the threshold), the control unit 13 sends an extrusion stop command to the extrusion device 21 to prevent the extrusion device 21 from extruding too much raw material metal 1. This makes it possible to prevent the electrode 14 from being broken by the metal raw material 1 in the melting chamber 18 .

[0089] Second Embodiment FIG. 5 is an explanatory diagram of an electric furnace facility 100A in which a height profile creation device 20A according to a second embodiment of the present invention is installed.

[0090] The electric furnace used in the electric furnace facility 100 in the first embodiment described above is a continuous charging electric furnace. However, the electric furnace used in the electric furnace facility may be of another charging type. The electric furnace used in the electric furnace facility 100A in this embodiment is a batch charging electric furnace.

[0091] In the melting equipment 110A of the electric furnace equipment 100A, the metal raw material 1 is transported in a bucket 15A, and is loaded into the melting chamber 18 from above by rotating and opening a furnace lid 16 on top of the melting chamber 18. After the furnace lid 16 is closed, three electrodes 14 are moved vertically, and arcs 4 are generated at the tips of the electrodes 14, and the metal raw material 1 is melted by the arc heat. The metal raw material 1 may also be melted while inputting combustion energy from a burner (not shown) or an oxygen gas injection lance (not shown).

[0092] In the height profile creation device 20A of this embodiment, the ranging radar 30A is installed midway between each electrode 14 and the furnace wall of the melting chamber 18 in the horizontal direction to measure the position of the top surface of the metal raw material 1. Because splashes are generated in the melting chamber 18 by the arc jet and oxygen jet, the ranging radar 30A may be periodically inserted for short periods of time to perform measurements in order to prevent deposits from the splashes generated in the melting chamber 18 from adhering to the tip of the water-cooled lance 31 equipped with the ranging radar 30A. The ranging radar 30A may also be equipped with a mechanism (not shown) for removing deposits while positioned outside the melting chamber 18. Furthermore, as shown in FIG. 5 , the ranging radar 30A measures the top surface position of the metal raw material 1 multiple times while changing its vertical position, thereby improving the accuracy of the height profile of the metal raw material 1 to be created.

[0093] 5, the metal raw material 1 in the melting chamber 18 begins to melt from the core around each electrode 14, and as the raw material 1 collapses, the position of the upper surface of the raw material 1 drops. This can cause differences in the progress of melting among the three electrodes 14.

[0094] Therefore, in the height profile creation device 20A of this embodiment, a distance measuring radar 30A is installed between each of the three electrodes 14 and the furnace wall of the melting chamber 18. That is, three distance measuring radars 30A are installed corresponding to each of the three electrodes 14. However, for convenience of illustration, only two distance measuring radars 30A are shown in Fig. 5. Based on data on the position of the top surface of the metal raw material 1 measured by each of the three distance measuring radars 30A, a height profile of the metal raw material 1 is created at a position corresponding to each of the three electrodes 14, and by comparing the height profiles of the three metal raw material 1, the uniformity of the progress of melting can be evaluated.

[0095] 5, the acquisition unit 11 of the control device 10A of this embodiment acquires data on the top surface position of the metal raw material 1 from the distance measuring radars 30A corresponding to each of the three electrodes 14. The calculation unit 12 then compares the measurement results at the positions measured by each of the three distance measuring radars 30A, and creates a height profile of the stationary metal raw material 1 by removing data on splashes, etc., and data where the velocity exceeds a threshold. From these height profiles of the metal raw material 1, the height of the metal raw material 1 in the lateral direction from the electrodes 14 to the furnace wall of the melting chamber 18 can be determined.

[0096] The control unit 13 compares the heights of the raw material metal 1 from the electrodes 14 to the furnace wall of the melting chamber 18 in the horizontal direction, and sends a command to the power supply unit 23 to reduce the power and voltage of the electrodes 14 whose melting is progressing and increase the power and voltage of the electrodes 14 whose melting is lagging, thereby improving the balance of melting among the three electrodes 14. The calculation unit 12 also integrates the height profiles of the raw material metal 1 corresponding to each of the three electrodes 14 to calculate the melting rate of the raw material metal 1 for the entire electric furnace equipment 100A. Then, when the melting of the raw material metal 1 in the melting chamber 18 progresses and the available space in the melting chamber 18 becomes equal to or greater than the volume of the raw material metal 1 in the bucket 15A, the calculation unit 12 sends a charge command to the bucket 15A to charge the raw material metal 1 into the melting chamber 18.

[0097] The height profile creation device 20A in this embodiment has a simple configuration including the above-mentioned ranging radar 30A, and can accurately measure the volume of the empty space in the melting chamber 18 and create an accurate height profile of the metal raw material 1. Furthermore, the control device 10A controls the electric furnace equipment 100A based on the height profile of the metal raw material 1 created by the height profile creation device 20A, thereby improving the thermal efficiency of the electric furnace equipment 100A and increasing productivity.

[0098] ===Other= ...

[0099] REFERENCE SIGNS LIST 1 Metal raw material 2 Molten metal 3 Slag 4 Arc 10, 10A Control device 11 Acquisition unit 12 Calculation unit 13 Control unit 14 Electrode 15 Skip 15A Bucket 16 Furnace lid 17 Lid 18 Melting chamber 19 Preheating chamber 20, 20A Height profile creation device 21 Push-out device 22 Shutter 23 Power supply device 30, 30A Ranging radar 31 Water-cooled lance 32 Cooling water flow path 33 Cap unit 90 Operator terminal 100, 100A Electric furnace equipment 110, 110A Melting equipment

Claims

1. An apparatus for creating a height profile of raw metal material, comprising: an electric furnace equipment having a melting chamber for melting raw metal material and an electrode inserted into the melting chamber from above, in which the raw metal material loaded into the melting chamber is melted by an arc generated from the electrode; a two- or more-dimensional ranging radar provided in a position capable of measuring an object to be measured within the electric furnace equipment; and a calculation unit which calculates a height profile of the raw metal material based on data on the object to be measured measured by the ranging radar.

2. The height profile creation device for metal raw materials as described in claim 1, characterized in that the ranging radar is a frequency continuous modulation radar, and the calculation unit is configured to calculate the height profile of the metal raw material based on data obtained by removing measurement data of at least one of dust and splash from the data of the measurement object using speed information of the measurement object.

3. The height profile creation device for metal raw materials as described in claim 1 or 2, characterized in that the distance measuring radar is provided at the upper inside of the melting chamber and is configured to be able to measure the measurement object within the melting chamber.

4. The height profile creation device for metal raw materials as described in claim 1 or 2, characterized in that the electric furnace equipment further comprises a preheating chamber for preheating the metal raw materials, which is directly connected to the melting chamber, and the ranging radar is provided at the upper inside part of the preheating chamber and is configured to be able to measure the measurement object within the preheating chamber.

5. The height profile creation device for metal raw materials as described in claim 1 or 2, characterized in that the electric furnace equipment further comprises a preheating chamber for preheating the metal raw material, which is directly connected to the melting chamber, and the ranging radar is provided on the inside upper part of the melting chamber and the inside upper part of the preheating chamber, and is configured to be able to measure the measurement object inside the melting chamber and the preheating chamber.

6. A control device for electric furnace equipment comprising: the metal raw material height profile creation device according to claim 3; and a control unit configured to control at least one of the timing and amount of metal raw material supplied to the melting chamber and the amount of energy input to the melting chamber, based on the height profile of the metal raw material in the melting chamber created by the metal raw material height profile creation device.

7. A control device for electric furnace equipment comprising: the metal raw material height profile creation device according to claim 4; and a control unit configured to control the timing and amount of supply of the metal raw material from the preheating chamber to the melting chamber based on the height profile of the metal raw material in the preheating chamber created by the metal raw material height profile creation device.

8. A control device for electric furnace equipment comprising: the metal raw material height profile creation device as described in claim 5; and a control unit configured to control at least one of the amount of energy input to the melting chamber and the timing and amount of the metal raw material supplied from the preheating chamber to the melting chamber based on a first profile which is a height profile of the metal raw material in the melting chamber and a second profile which is a height profile of the metal raw material in the preheating chamber, which are created by the metal raw material height profile creation device.

9. An electric furnace equipment comprising a melting chamber for melting a metal raw material and an electrode inserted into the melting chamber from above, the metal raw material charged into the melting chamber being melted by an arc generated from the electrode, the electric furnace equipment comprising the control device according to claim 6.

10. An electric furnace equipment comprising a melting chamber for melting a metal raw material and an electrode inserted into the melting chamber from above, the metal raw material charged into the melting chamber being melted by an arc generated from the electrode, the electric furnace equipment comprising the control device according to claim 7.

11. An electric furnace equipment comprising a melting chamber for melting a metal raw material and an electrode inserted into the melting chamber from above, the metal raw material charged into the melting chamber being melted by an arc generated from the electrode, the electric furnace equipment comprising the control device according to claim 8.

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