Metal casting equipment

Abstract

A metal casting device, comprising: a loading platform; a tundish; a first ladle and a second ladle, including: a bottom plate provided with an opening; a collecting nozzle and a ladle long nozzle; a ladle sliding gate configured to move the collecting nozzle and the ladle long nozzle between a sealed position, a casting position, and a dredging position, in the sealed position, the opening is sealed, in the casting position, the opening faces the ladle long nozzle, and in the dredging position, the opening faces the collecting nozzle; (d) a turntable for holding the first ladle and the second ladle, configured to move the first ladle and the second ladle between a loading station and a casting station above the tundish (1) and hold them in place, the metal casting device includes a robot configured to perform the following operations on the first ladle or the second ladle held at the loading station: loading a new ladle long nozzle onto the ladle sliding gate and connecting a driving device to the ladle sliding gate.

Description

Technical Field

[0001] The present invention relates to a metal casting apparatus having a robot-operated loading station for preparing a fresh ladle loaded on a rotating turntable before bringing the fresh ladle above a tundish at a casting station. In particular, the present invention relates to a robot-operated apparatus for loading a ladle long nozzle into a ladle sliding gate coupled to an outlet of the ladle, and for coupling a drive device to both the ladle and the ladle sliding nozzle to drive the ladle sliding gate. The robot-operated loading station is also configured to disconnect the drive device and unload a used ladle long nozzle from an empty ladle which has been recently removed from the casting station above the tundish. Performing these operations with a robot frees the operator from strenuous work and improves the repeatability of the operation. A particular ladle sliding gate includes a collector nozzle positioned adjacent to the ladle long nozzle, thereby allowing rapid unblocking of the outlet when the outlet becomes blocked. Background Art

[0002] In a continuous metal forming process, a metal melt 2 is transferred from one metallurgical container to another, to a mold or tool. For example, as shown in FIG. 1, ladles 11, 12 are filled with a metal melt from a furnace (not shown) and transferred above a tundish 1 to discharge the molten metal from the ladle into the tundish through ladle long nozzles 13a - 13c. The metal melt can then be cast from the tundish through a pouring nozzle 3 into a mold or tool to continuously form slabs, billets, beams, thin slabs, etc. Under the action of gravity, the metal melt flows from the ladle into the tundish and then from the tundish into the mold or tool. The flow rate can be controlled by a sliding nozzle mechanism in fluid communication with the outlets of the ladle and the tundish. A ladle sliding gate 15 can be used to control the flow rate leaving the ladle and even interrupt the flow in a sealed position. Similarly, a tundish sliding nozzle mechanism 5 can be used to control the flow rate leaving the tundish and interrupt the flow in a sealed position.

[0003] Since the casting of metal into a mold or tool is to be carried out continuously, the tundish serves as a buffer, and during the entire casting operation, the level of the molten metal in the tundish must be kept substantially constant. Keeping the level of the molten metal in the tundish substantially constant requires a rapid exchange of a new ladle filled with molten metal for an old ladle after the old ladle has been emptied, to ensure a quasi-continuous feed of molten metal into the tundish such that the metal is poured into the tundish at a rate substantially the same as the rate at which it flows out of the tundish into the mold or tool. This operation becomes more complex due to the following constraints.

[0004] First, due to safety reasons and to avoid any collisions, the ladles 11, 12 cannot be transported from the melting furnace to the corresponding tundishes within the workshop. The ladle long nozzles 13a - 13c are connected to the bottom plate of the ladle and extend 1 m or more below the bottom plate. The ladle long nozzles must be connected to the bottom plate of the ladle at the loading station near the tundish.

[0005] Secondly, to prevent the metal contained in the second ladle 12 from freezing by contacting the "cold" moving part of the ladle slide gate 15 held in the sealed position, thus avoiding jamming the mechanism and preventing the ladle slide gate from opening, the inner hole of the submerged entry nozzle is generally filled with a blocking material 19, usually sand or other granular materials, to prevent any molten metal from reaching the nozzle mechanism, thereby preventing metal freezing and blocking of the nozzle and nozzle mechanism system. When the ladle is in the casting station, after the ladle slide gate is opened to the casting position, the sand flows out, and then the molten metal can flow through the ladle long nozzle into the tundish. However, sometimes the blocking material will locally combine with the frozen metal to form a solid blockage, preventing the blocking material from flowing out. As a result, the submerged entry nozzle is blocked, and although the ladle slide gate is in the casting position, the metal cannot flow out of the ladle into the tundish. This problem can be easily solved by inserting a cleaning tool 19r into the hole of the submerged entry nozzle or inserting the cleaning tool near the hole of the submerged entry nozzle. The cleaning tool 19r can be a pressurized gas spray gun or a long rod, as shown in Figures 2(c) and 3(c). Now, due to the long ladle long nozzles 13a - 13c connected to the ladle slide gate, this seemingly simple operation is actually quite complex.

[0006] For this reason, in most equipment, the ladle long nozzle is not connected to the slide nozzle mechanism in an autonomous manner at the loading station. Instead, the ladle long nozzle is inserted above the collecting nozzle and held in place by a robot at the casting station. This allows the robot to remove the ladle long nozzle from the collecting nozzle in case of blockage at the ladle outlet, so that the ladle outlet can be more easily accessed from the bottom with the cleaning tool 19r. Once the blocked passage is cleared, the ladle slide gate can be moved to the sealed position while the robot reintroduces the ladle long nozzle above the collecting nozzle. At this time, the ladle slide gate is moved back to the casting position to start pouring the molten metal into the tundish.

[0007] The newly filled ladle is transported from the melting furnace to the casting equipment, where the ladle slide gate is fixed to the bottom plate of the ladle, but there is no driving device to drive the relative movement of the plates forming the ladle slide gate. For this purpose, many metallurgical devices use a turntable 30, which includes a first holding device for holding a first ladle 11 at the casting station above the tundish 1 and a second holding device for holding a second ladle 12 filled with molten metal at the loading station. When the first ladle discharges the molten metal contained therein into the tundish, once the first ladle is emptied, the second ladle can be prepared for the same operation. In particular, a driving device such as a hydraulic piston can be coupled to the bottom plate of the ladle and the ladle slide gate to allow driving of the bottom plate of the ladle and the ladle slide gate.

[0008] US 2006 / 0118268 describes a ladle slide gate configured to autonomously hold a ladle long nozzle and a collecting nozzle arranged side by side. One or more driving devices such as hydraulic pistons can be used to drive the ladle slide gate by moving the plate of the ladle slide gate between a sealed position where the opening therein is sealed, a casting position where the opening is in fluid communication with the ladle long nozzle, and a clearing position where the opening is in fluid communication with the collecting nozzle. Thus, in the case of blockage of the inner hole, the ladle slide gate moves to the clearing position, so that a clearing tool 19r can be easily introduced through the short collecting nozzle hole to break the blocking material combined with the solidified metal. Once the blocking material can flow again, the ladle slide gate moves the collecting nozzle to a position misaligned with the ladle outlet and brings the ladle long nozzle into the casting position so that the molten metal flows through the ladle long nozzle into the tundish. The manipulation of the clearing tool 19r can advantageously be performed by a robot located near the casting station. Compared with the above-described holding of the ladle long nozzle by a robot, the obvious advantage is that with this ladle slide gate, there is no need for a robot to hold the ladle long nozzle, and instead, the robot can be used to manipulate the clearing tool 19r. Otherwise, this operation has to be performed manually by a human operator or a second robot has to be installed near the casting station to clear the inner hole. Compared with the robot performing this operation, manual manipulation is generally more laborious and takes longer. This is disadvantageous because the longer the ladle does not supply fresh molten metal to the tundish, the lower the liquid level of the molten metal in the tundish and / or the longer the casting operation has to be performed at a lower flow rate, which will damage the quality of the beam thus produced. Examples of this type of ladle slide gate that holds the collecting nozzle and the ladle long nozzle side by side are shown in FIGS. 2(a)-(d) and FIGS. 3(a)-(d) and are discussed in more detail below.

[0009] US 8215375 describes a continuous casting apparatus having at least one multi-functional robot for performing a variety of different process-controlled or automated interventions on the continuous casting apparatus. The multi-functional robot disposed on a pivotable arm at a rotating column can be pivoted by the pivot arm between a retracted position and a working position, and the rotating column is fastened to a pouring platform and a robot of the continuous casting apparatus. The robot can also move relative to its arm.

[0010] The operation of quickly exchanging an emptied first ladle with a filled second ladle at the casting station remains a delicate operation. In the case of blockage of the inner hole - which may increase the time during which the tundish is not filled with fresh molten metal - this operation becomes even more critical. In the metal casting industry, a repeatable and shorter ladle exchange operation is needed. The present invention provides a metal casting apparatus having a fully automated ladle replacement operation, including allowing a repeatable and in all cases shorter exchange operation in the case where the outlet of the ladle is blocked by a blocking material 19. These and other advantages of the present invention will be described in more detail in the following sections. Summary of the Invention

[0011] The object of the present invention is achieved by a metal casting apparatus comprising:

[0012] (a) a loading platform,

[0013] (b) a tundish,

[0014] (c) a first ladle and a second ladle, each of the first ladle and the second ladle comprising:

[0015] · a bottom plate provided with an opening,

[0016] · a collecting nozzle and a ladle long nozzle,

[0017] · a ladle sliding gate configured to reversibly receive and support the collecting nozzle and the ladle long nozzle and further configured to be coupled to a drive device for driving the ladle sliding gate between a sealed position, a casting position, and a dredging position, wherein in the sealed position, the opening is sealed, in the casting position, the opening is in fluid communication with the ladle long nozzle, and in the dredging position, the opening is in fluid communication with the collecting nozzle,

[0018] (d) a turntable comprising at least a first holding device and a second holding device for respectively holding the first ladle and the second ladle, wherein the ladle turntable is configured to move and hold in place the first ladle and the second ladle between a loading station adjacent to the loading platform and a casting station above the tundish,

[0019] The metal casting equipment includes a robot configured to perform the following operations on the first ladle or the second ladle held at the loading station:

[0020] · Loading a new ladle long nozzle onto the ladle slide gate, and

[0021] · Connecting a driving device to the ladle slide gate.

[0022] The robot is preferably further configured to remove the following devices from the emptied first ladle or second ladle held at the loading station after moving from the casting station:

[0023] · The ladle long nozzle, and

[0024] · The driving device.

[0025] Preferably, the loading platform includes a tool storage rack that contains one or more spare ladle long nozzles within the reach of the robot. The spare ladle long nozzles can be preheated in the storage rack or in a separate oven. The storage rack preferably includes one or more driving devices and / or additional spare collecting nozzles, and / or tools.

[0026] In a preferred embodiment, the robot is movably mounted on the loading platform such that the robot can translate along a first axis X and / or a second axis Y perpendicular to the first axis X, or translate in a combination of the above two movements, and / or rotate about a vertical axis Z perpendicular to the first axis X and the second axis Y, so as to reach the storage rack and retrieve any tool or component therefrom and reach the ladle slide gate of the first ladle or the second ladle held at the loading station to perform the operations of loading / unloading the ladle long nozzle and connecting / removing the driving device.

[0027] The ladle slide gate is important for the present invention. In a first embodiment, the ladle slide gate includes:

[0028] (a) An upper plate that includes:

[0029] · A fixed surface and a bottom sliding surface that are spaced apart from each other by the thickness of the upper plate;

[0030] · An upper hole that extends from the fixed surface to the bottom sliding surface, and wherein

[0031] · The fixed surface of the upper plate is rigidly fixed to the lower part of the corresponding first ladle or second ladle, and the upper hole is in fluid communication with the opening,

[0032] (b) A lower plate that includes:

[0033] · A tundish sliding surface and a top sliding surface, the tundish sliding surface and the top sliding surface being spaced apart from each other by the thickness of the lower plate;

[0034] · A lower hole extending from the top sliding surface to the tundish sliding surface, wherein

[0035] · The lower plate is slidably mounted such that the top sliding surface can slide translationally along the bottom sliding surface to fluidly connect and disconnect the lower hole from the upper hole, and wherein

[0036] (c) A drawer configured to rigidly hold a ladle long nozzle and a collecting nozzle, the ladle long nozzle having a ladle long nozzle hole open at the upper surface of the long nozzle, the collecting nozzle having a collecting nozzle hole open at the upper surface of the collecting nozzle, the drawer being movably mounted so that the upper surface of the long nozzle and the upper surface of the collecting nozzle translate between a long nozzle position and a collecting nozzle position along the tundish sliding surface of the lower plate, at the long nozzle position, the ladle long nozzle hole is fluidly connected to the lower hole, and at the collecting nozzle position, the collecting nozzle hole is fluidly connected to the lower hole,

[0037] (d) The drive device is coupled to the lower plate to drive the translation of the lower plate, and

[0038] (e) A drawer drive device coupled to the drawer to drive the translation of the drawer,

[0039] wherein the drive device is coupled to the lower plate and includes a cylinder and a piston, the cylinder being rigidly and reversibly coupled to the bottom of the corresponding first ladle or second ladle, the piston being rigidly and reversibly fixed to the lower plate, the drive device being configured to move the lower plate to align or misalign the lower hole with the upper hole, and

[0040] wherein the drawer drive device is coupled to the drawer and includes a cylinder and a piston, the cylinder being rigidly and reversibly coupled to the bottom of the corresponding first ladle or second ladle, the piston being rigidly and reversibly fixed to the drawer, the drawer drive device being configured to move the drawer to align or misalign the ladle long nozzle hole and the collecting nozzle hole with the lower hole.

[0041] In an alternative embodiment, the ladle slide gate includes:

[0042] (a) An upper plate including:

[0043] · A fixed surface and a bottom sliding surface, the fixed surface and the bottom sliding surface being spaced apart from each other by the thickness of the upper plate;

[0044] · An upper hole extending from the fixed surface to the bottom sliding surface, and wherein

[0045] · The fixing surface of the upper plate is rigidly fixed to the lower part of the corresponding first ladle or second ladle, wherein the upper hole is in fluid communication with the opening.

[0046] (b) A lower plate, which comprises:

[0047] · A nozzle surface and a top sliding surface, the nozzle surface and the top sliding surface being spaced apart by the thickness of the lower plate from each other;

[0048] · A first hole and a second hole, each of the first hole and the second hole extending from the top sliding surface to the nozzle surface, wherein

[0049] · The lower plate is slidably mounted such that the top sliding surface can slide along the bottom sliding surface to bring each of the first hole and the second hole into and out of fluid communication with the upper hole, and wherein

[0050] · The nozzle surface is configured to be rigidly and reversibly coupled to the ladle long nozzle and the collecting nozzle, the ladle long nozzle having a ladle hole in fluid communication with the first hole, and the collecting nozzle having a collecting nozzle hole in fluid communication with the second hole,

[0051] And wherein the drive device is coupled to the lower plate and comprises a cylinder and a piston, the cylinder being rigidly and reversibly coupled to the bottom of the corresponding first ladle or second ladle, the piston being rigidly and reversibly fixed to the lower plate, and the drive device being configured to move the lower plate to align or misalign the first hole and the second hole with the upper hole.

[0052] The drive device can be actuated hydraulically or pneumatically or electrically. Each of at least the first holding device and the second holding device of the ladle turntable can be provided with:

[0053] · A pressurized fluid source for actuating the drive device via a hose, or a power source, and

[0054] · Preferably a storage station for storing the drive device ready to be coupled to the ladle slide gate.

[0055] In a preferred embodiment, a preheating oven is provided for bringing a new ladle long nozzle loaded on the ladle slide gate of the first ladle or second ladle located at the loading station to and maintaining it at a preheating temperature. The preheating oven can be provided as an alternative to or in addition to a heating and heat storage rack or a separate oven for preheating the new ladle long nozzle before coupling it to the ladle.

[0056] In a preferred embodiment, the robot is further configured for:

[0057] · Checking the state of the used ladle long nozzle after the used ladle long nozzle is removed from the emptied ladle.

[0058] · Evaluate whether the used tundish nozzle can be reused after cleaning or whether it must be discarded, and

[0059] · Advantageously, clean the used tundish nozzle with an oxygen sprayer to remove any residue adhering to the walls of the used tundish nozzle.

[0060] The present invention also relates to a method for casting molten metal, the method comprising the following steps:

[0061] (a) Provide a metal casting apparatus as described above, wherein,

[0062] · The first ladle is filled with molten metal and is in the casting station, and

[0063] · The second ladle is filled with molten metal and is in the loading station,

[0064] · The ladle slide gate of the first ladle is in the sealed position, is coupled to one or more drive devices or an optional drawer drive device, and is provided with a tundish nozzle and a collecting nozzle,

[0065] · The ladle slide gate of the second ladle is in the sealed position but does not include a tundish nozzle and an operating drive device and an operating drawer drive device,

[0066] (b) Move the ladle slide gate of the first ladle to the casting position so as to cast molten metal from the first ladle through the tundish nozzle into the tundish,

[0067] (c) During the previous step,

[0068] · Load a new tundish nozzle onto the ladle slide gate of the second ladle with the robot, and

[0069] · Couple the drive device to the slide plate nozzle mechanism of the second ladle with the robot,

[0070] (d) When the first ladle is substantially empty, move the ladle slide gate of the first ladle to the sealed position, and then

[0071] (e) Exchange the positions of the first ladle and the second ladle by moving the first ladle from the casting station to the loading station and concomitantly moving the second ladle from the loading station to the casting station,

[0072] (f) Move the ladle slide gate of the second ladle to the casting position and cast molten metal from the second ladle through the tundish nozzle into the tundish.

[0073] In a preferred embodiment, the method during step (f) comprises the following steps:

[0074] (g) Using the robot to remove the used tundish nozzle from the ladle slide gate of the emptied first ladle and storing the used tundish nozzle for refurbishment or discarding as waste, and

[0075] (h) Using the robot to disconnect and remove the one or more drive means from the slide gate mechanism of the first ladle and storing the one or more drive means for further use,

[0076] (i) Removing the emptied first ladle, and

[0077] (j) Loading a new ladle filled with molten metal onto the first holding means of the ladle turntable at the loading station, wherein, like the second ladle in step (a), the new ladle includes a ladle slide gate in the closed position but does not include a tundish nozzle.

[0078] In many cases, the opening of the first ladle is filled with a blocking material to prevent the metal from solidifying upon contact with the cold surface of the upper plate of the ladle slide gate. The blocking material is generally in granular form. In some cases, some molten metal may seep through the granular blocking material and solidify, thereby forming a solid mass that blocks the opening, thus preventing any molten metal from flowing out of the opening when the ladle slide gate of the first ladle enters the casting station in step (b). When such a blockage occurs, the following steps can be performed to clear the opening.

[0079] · Move the ladle slide gate of the first ladle to the clearing position,

[0080] · Use a suitable clearing tool to clear the opening of the first ladle by breaking up the blocking material,

[0081] · When the blocking material starts to flow out of the collecting nozzle, move the ladle slide gate of the first ladle to the casting position so as to pour molten metal from the first ladle through the thus cleared opening and through the tundish nozzle into the tundish.

[0082] The step (e) of exchanging the positions of the first ladle and the second ladle preferably comprises the following steps:

[0083] · Lift the first ladle and the second ladle until the tundish nozzles of both the first ladle and the second ladle are disengaged from the tundish and are above the tundish in the vertical direction Z,

[0084] · Rotate the turntable 180° about the vertical axis Z so that the first ladle is above the loading station and the second ladle is above the casting station and above the tundish,

[0085] ·Lower the first ladle and the second ladle to their respective loading stations and casting stations, and insert the ladle long nozzle of the second ladle into the tundish.

[0086] In a preferred embodiment, the robot also:

[0087] ·Check the condition of the used ladle long nozzle after it has been removed from the emptied ladle,

[0088] ·Evaluate whether the used ladle long nozzle can be reused after cleaning or whether it must be discarded, and

[0089] ·Clean the used ladle long nozzle with an oxygen spray to remove any residue adhering to the walls of the used ladle long nozzle. Description of the Drawings

[0090] In these drawings,

[0091] Figures 1(a)-(f) depict the various steps of replacing the emptied first ladle from the casting station and replacing the first ladle with the second ladle after the full second ladle is ready at the loading station.

[0092] Figures 2(a)-(d) show the various steps of unclogging a blocked ladle outlet using a ladle slide gate according to a first embodiment of the present invention.

[0093] Figures 3(a)-(d) show the various steps of unclogging a blocked ladle outlet using a ladle slide gate according to a second embodiment of the present invention. Detailed Description

[0094] As shown in Figures 1(a)-(f), the metal casting equipment according to the present invention includes a first ladle 11 and a second ladle 12. The first ladle is held at a casting station above the tundish 1, and this casting station is used to transfer the molten metal 2 contained in the first ladle 11 to the tundish 1. The tundish transports the molten metal to a tool or a mold. Through this system, the tundish contains a certain volume of molten metal, and this volume remains substantially constant throughout the transfer of the molten metal from the first ladle 11 to the tundish 1. When the first ladle has been emptied of its contents, the first ladle must be replaced as quickly as possible with the second ladle 12 filled with molten metal and fully shifted gears, in order to continue transferring the molten metal 2 to the tundish 1, so as to keep the liquid level of the molten metal in the tundish substantially constant, while maintaining the flow rate of the molten metal flowing out of the tundish into the tool or the mold.

[0095] The ladles 11, 12 include a bottom plate provided with openings 11o, 12o. The submerged entry nozzle 18 provided with an inner hole fluidly connects the internal volume of the tundish with the openings 11o, 12o. The ladles 11, 12 further include a ladle slide gate 15 which is configured to reversibly receive and support the ladle long nozzle and to be coupled to a drive device 17 for driving the ladle slide gate between a sealed position and a casting position, in which the opening is sealed in the sealed position and the opening is in fluid communication with the ladle long nozzle 13a - 13c in the casting position.

[0096] The ladle slide gate 15 of the ladle according to the invention is further configured to reversibly receive and support the collecting nozzles 14a, 14b. The drive device 17 or the drawer drive device 17w is further configured to drive the ladle slide device 15 to a dredging position, in which the opening is in fluid communication with the collecting nozzle 14. As explained in more detail below, the dredging position is used when the ladle slide gate is in the casting position due to blockage and no molten metal flows out of the ladle.

[0097] To accelerate the exchange between the emptied first ladle 11 and the filled second ladle 12, the first ladle and the second ladle are supported by respective first and second holding devices of a rotating turntable 30 (see FIG. 1(a)). The first and second holding devices are fork arms which hold the first ladle and the second ladle 11, 12 at an "arm length" from the central axis of rotation Z. The rotation of the turntable about the central axis of rotation Z allows the first ladle and the second ladle to move between the following positions:

[0098] · A casting station, in which one of the first ladle or the second ladle 11, 12 is held above the tundish and the ladle long nozzle 13a - 13c is partially inserted into the tundish, and

[0099] · A loading station, in which the other of the first ladle or the second ladle is shifted at the loading station to prepare for transferring molten metal into the tundish when the shifted ladle is moved to the casting station.

[0100] Since the ladle long nozzle 13a - 13c is partially inserted into the tundish 1, the turntable 30 must first lift the first ladle and the second ladle before rotating about the central axis of rotation Z to drive the ladle long nozzle 13a of the first ladle 11 out of the tundish 1 and to a position above the tundish to avoid collision of the ladle long nozzles of the first ladle and the second ladle with the tundish.

[0101] Loading is carried out using the loading platform 20, which includes tools and spare parts, such as new ladle long nozzles 13b, 13c, new collecting nozzles 14, or spare drive units 17. As explained above, the ladle cannot be transported across the workshop between the melting furnace and the casting equipment because the long ladle long nozzles 13a - 13c protrude from the bottom plate of the ladle. Thus, a fresh ladle filled with molten metal without the ladle long nozzles 13a - 13c arrives at the casting station. The fresh ladles 11, 12 filled with molten metal 2 arrive at the turntable 30. The ladle slide gate 15 is fixed to the bottom plate of the ladle but there is no operable drive unit 17, and the collecting nozzle 14 is connected to the ladle slide gate. The collecting nozzle is very short and can be attached to the ladle and transported across the workshop without any risk of collision. Thus, when the fresh ladle 12 docks at the turntable 30 at the loading station, the new ladle long nozzles 13a - 13c can be connected to the fresh ladle. At the same time, the drive unit 17 must be connected to the ladles 11, 12 and the ladle slide gate 15 and must be activated by connecting it to a pressurized fluid source for a hydraulic or pneumatic drive unit 17 or to a power source for an electric drive unit 17.

[0102] The present invention proposes providing a robot 21 on or near the loading platform 20 instead of manually performing these operations by a human operator. The robot 21 is configured to load the new ladle long nozzle 13b onto the ladle slide gate 15 and to connect the drive unit 17 to the ladle slide gate 15.

[0103] Casting equipment

[0104] Figures 1(a)-(f) show the various steps of a continuous casting operation using the apparatus according to the invention. The exchange of the emptied first ladle 11 and the filled second ladle 12 will be discussed in more detail in the following sections. Figure 1(a) shows the turntable 30, which includes a first holding device and a second holding device for holding the first ladle and the second ladle 11, 12. The turntable is located near the tundish such that each of the first holding device and the second holding device can bring the ladles 11, 12 to the casting station, where the ladle long nozzle is partially inserted into the tundish, below the liquid level of the molten metal contained in the tundish during use under stable conditions. Figure 1(a) shows such a configuration, in which the first ladle 11 is partially filled with molten metal and is held at the casting station by the first holding device of the turntable 30. The first ladle is above the tundish 1, where the ladle long nozzles 13a-13c are partially inserted into the tundish and are partially immersed below the liquid level of the molten metal contained in the tundish. The ladle slide gate 15 of the first ladle 11 is connected to a drive device 17, which is configured to move the plate of the sliding nozzle mechanism between the above-mentioned sealing position, casting position, and purging position. In the embodiment of Figures 1(a)-(f), the drive device 17 is a hydraulic piston, which is connected to a pressurized fluid source 17h through a hose 17t. The drive device 17 can be pneumatic or electric, but a hydraulic drive device is preferred.

[0105] The second ladle 12 filled with molten metal directly from the furnace is held at the loading station by the second holding device of the turntable 30, which is within the reach of the robot on the loading platform 20. The ladle slide gate 15 of the second ladle 12 is in the sealing position. Different from the first ladle 11, the second ladle 12 is not ready to cast molten metal because it does not have any ladle long nozzle 13b and any drive device 17. The second ladle 12 could be equipped with a drive device 17, but the drive device is not in an operating state because it is not connected to any pressurized fluid source for hydraulic and pneumatic drive devices or to an electrical power source for an electric drive device. Generally, the second ladle 12 arrives at the turntable without any drive device 17, and in the few cases where it has a drive device, the drive device is also inoperative.

[0106] The charging platform 20 includes a storage rack 29, which has various tools (not shown) required for preparing the second ladle 12 for casting, and has spare ladle long nozzles 13b, 13c. Preferably, the first ladle long nozzles 13a, 13c for connection to the ladle are preheated in the storage rack 29 or in a separate oven within the reach of the robot to avoid any severe thermal shock when the molten metal flows through the ladle collecting nozzle after the casting operation starts at the casting station. In some cases, the platform may include a spare drive device 17 and may include a spare collecting nozzle 14. However, before filling the ladle with molten metal from the furnace, the collecting nozzle 14 is preferably connected to the second ladle at a separate refurbishment station.

[0107] Preferably, the drive device 17 for driving the ladle slide gate 15 of the second ladle 12 and the optional drawer drive device 17w (defined hereinafter with respect to the first embodiment shown in FIGS. 2(a)-(d)) are stored on or near the second holding device of the turntable 30. The drive device is preferably stored on the first holding device and the second holding device because in this way, it is not necessary to connect and disconnect from the (drawer) drive device each time when connecting to or removing from the ladle, because as shown in FIG. 1(a), it is most convenient to also locate the pressurized fluid source 17h on or near the first holding device and the second holding device.

[0108] Figure 1(b) shows that when the first ladle 11 discharges its molten metal content into the tundish, the robot 21 removes a new ladle long nozzle 13b from the storage rack 29 and attaches the new ladle long nozzle to the ladle slide gate 15 of the second ladle 12, keeping the ladle slide gate in the sealed position throughout the entire stay of the second ladle at the loading station. As explained above, in the preferred embodiment, before being attached to the ladle slide gate, the new ladle long nozzle 13b is heated to the preheating temperature in the storage rack 29 or in a separate oven within the reach of the robot 21. Preheating the ladle long nozzle before casting reduces the risk of cracking due to severe thermal shock, since molten metal only starts flowing through the ladle long nozzle at the start of the casting operation. Since the second ladle 12 equipped with the new ladle long nozzle 13b can stay at the loading station for a certain period of time waiting for the first ladle 11 to be emptied before being moved to the casting station, the new ladle long nozzle 13b has time to cool down and loses all the benefits of the preheating operation. For this reason, in the preferred embodiment of the present invention shown in Figure 1(c), as a supplement or alternative to preheating the new ladle long nozzle in the storage rack or a separate oven, a preheating oven 25 can be provided at the loading station for keeping the new ladle long nozzle 13b (optionally reaching and) staying at the preheating temperature on the ladle slide gate 15 of the second ladle 12 located at the loading station. With this preheating oven 25, the ladle long nozzle reaches the casting station at the required preheating temperature, and casting can start with a lower risk of cracking due to thermal shock. The preheating oven 25 can be movably attached to the loading platform 20, or to the first and second holding devices of the turntable. The preheating oven preferably takes the form of an open book and will close over the new ladle long nozzle 13b once the new ladle long nozzle has been attached to the ladle slide gate 15. The robot 21 can manipulate the oven to bring it into the preheating position.

[0109] The robot 21 can preferably move along a horizontal plane (X, Y) and has several degrees of freedom, preferably at least five or at least seven degrees of freedom. The robot must be able to reach the storage rack 29 to collect or deposit tools and / or casting components, and must also be able to reach the ladle slide gate 15 of the ladle staying at the loading station. The robot must have sufficient degrees of freedom to perform all the connections and disconnections, as well as the couplings and uncouplings required to ensure continuous casting operation of the casting equipment.

[0110] In particular, as shown in FIGS. 1(b) and 1(c), the robot must be configured for the (disconnectable) coupling of the ladle long nozzles 13a - 13c and the (drawer) drive devices 17, 17w, and for the (disconnectable) coupling of the hoses 17t to the (drawer) drive devices 17, 17w. In FIGS. 1(a) - (f), both the first and second holding devices of the turntable 30 are provided with:

[0111] · A storage station for storing one or more (drawer) drive devices 17, 17w, and

[0112] · A pressurized fluid source connected to the one or more (drawer) drive devices for driving the ladle slide gate 15.

[0113] With this configuration, all that the robot 21 has to do is collect the drive device 17 from its storage station at the second holding device and couple it to the ladle and the ladle slide gate 15. If the drive device is stored in the storage rack 29, or if the drive device stored in the storage station has to be replaced with a new drive device stored in the storage rack 29, then in addition to coupling the one or more (drawer) drive devices 17, 17w to the ladle and the ladle slide gate 15, the robot 21 must also connect one or more hoses 17t to the respective (drawer) drive devices so that the drive devices operate to drive the ladle slide gate.

[0114] As shown in FIG. 1(d), when the first ladle 11 is substantially empty, it must be replaced by the full second ladle 12 waiting at the loading position. In the embodiment shown in FIGS. 1(a) - (f), the turntable 30 is configured to raise the first and second ladles 11, 12 to a rotation height to ensure that when the turntable rotates, the ladle long nozzles 13a, 13b of the first and second ladles do not collide with the tundish 1 or any other element of the casting equipment. As shown in FIG. 1(e), the turntable 30 is also configured to rotate about the vertical axis Z so as to exchange the positions of the first and second ladles in a single movement, with the first and second ladles remaining at the rotation height above their respective loading and casting positions. Finally, the turntable 30 must be configured to lower the first and second ladles to their respective loading and casting stations, as shown in FIG. 1(f).

[0115] The movement of the turntable and the movement of the ladle slide gates 15 of both the first and second ladles must be completely synchronized to prevent any unwanted dripping or outflow of molten metal from either of the first and second ladles.

[0116] The robot 21 must also be configured to remove the ladle long nozzle 13a and the drive device 17 from the emptied first ladle 11 located at the loading station. The used ladle long nozzle 13a can be cleaned and stored for further use, or it can be discarded into the waste bin 27. The drive device 17 can be stored in the storage station on the first holding device of the turntable 30 without disconnecting it from the pressurized fluid source, or it can be stored in the storage rack 29 of the loading platform after it has been disconnected from the pressurized fluid source. Now, the emptied first ladle 11, which has had both the ladle long nozzle 13a and the drive device 17 removed, can be removed to the repair station for refurbishment. A new ladle filled with molten metal can be brought out from the furnace and loaded onto the now-empty first holding device of the turntable to initiate the entire operation, as discussed above. Figure 1(a) to Figure 1(f) as shown.

[0117] The robot 21

[0118] The robot 21 can have at least five, preferably at least six or seven degrees of freedom. The robot is preferably movably mounted on the loading platform 20 such that the robot can translate parallel to the first axis X and / or the second axis Y perpendicular to the first axis X, or translate in a combination of the two motions. The robot 21 can preferably rotate about a vertical axis Z perpendicular to the first axis X and the second axis Y. Through the combination of these motions, the robot must be able to reach the storage rack 29 and retrieve any tool or component from the storage rack, and be able to reach the ladle slide gate 15 of the first ladle or the second ladle 11, 12, which is held at the loading station for the operations described below. Excellent results have been obtained using a Kuka Foundry type robot KR480.

[0119] The robot is configured to couple the ladle long nozzles 13a - 13c and the drive device 17 to the ladles 11, 12 filled with molten metal and their ladle slide gates 15. The robot is also configured to remove the used ladle long nozzles 13a - 13c and the drive device 17 from the emptied first or second ladle 11, 12 held at the loading station after moving from the casting station. To avoid severe thermal shock, preferably, the ladle long nozzle is surrounded in a preheating station before the ladle long nozzle 13b is coupled to the ladle slide gate 15 of the ladle at the loading station. The robot can manipulate the ladle long nozzle from the storage rack 29 to the preheating station (not shown) and then couple it to the ladle slide gate 15. Similarly, to remove the ladle long nozzle from the emptied first ladle 11, the robot can remove the ladle long nozzle, take it to a pressurized gas (such as oxygen) cleaning station (not shown) and the preheating station or the storage rack 29 for further use. Alternatively, if the ladle long nozzle is too worn to be used further, the robot can discard it into the waste bin 27.

[0120] The robot is also configured to inspect the condition of the used ladle long nozzles 13a - 13c after they are removed from the emptied ladle. In a preferred embodiment, the robot is configured to evaluate whether the used ladle long nozzles can be reused after cleaning or whether they must be discarded. This can be achieved through the artificial intelligence programming of the robot, which can "learn" to determine whether the used ladle long nozzles can be reused or must be discarded. The robot is also preferably configured to advantageously clean the used ladle long nozzles with an oxygen sprayer to remove any residues adhering to the walls of the used ladle long nozzles.

[0121] Ladle slide gate 15

[0122] The ladle slide gate 15 applicable to the present invention includes an upper plate 15u and a lower plate 15d. The upper plate includes a fixed surface and a bottom sliding surface, and an upper hole, the fixed surface and the bottom sliding surface being spaced apart from each other by the thickness of the upper plate, and the upper hole extending from the fixed surface to the bottom sliding surface. The fixed surface of the upper plate is rigidly fixed to the lower part of the corresponding first or second ladle 11, 12, wherein the upper hole is in fluid communication with the openings 11o, 12o. As shown in FIGS. 2(a) and 3(a), the openings are generally formed by the downstream end of the inner hole of the submerged nozzle 18. During the entire casting operation from the ladles 11, 12 to the tundish 1, the upper plate 15u is fixed relative to the openings 11o, 12o and the submerged nozzle 18.

[0123] The lower plate 15d includes a nozzle sliding surface and a top sliding surface, and one or two lower holes. The nozzle sliding surface and the top sliding surface are spaced from each other by the thickness of the lower plate. The one or two lower holes extend from the top sliding surface to the nozzle sliding surface. The lower plate 15d is slidably mounted such that the top sliding surface can slide translationally along the bottom sliding surface to fluidly connect and disconnect the one or two lower holes from the upper hole. The lower plate can be moved translationally by activating the drive device 17. The drive device can include a cylinder 17c rigidly and reversibly coupled to the bottom of the first ladle or the second ladle 11, 12, and a piston 17p reversibly fixed to the lower plate 15d. For example, the drive device 17 can be a hydraulic piston or a pneumatic piston.

[0124] In the first embodiment shown in FIGS. 2(a)-(d), the lower plate 15d includes only one lower hole. The ladle slide gate of this embodiment includes a drawer 15w configured to rigidly hold the side-by-side ladle long nozzles 13a-13c and the collecting nozzle 14. The ladle long nozzle has a long nozzle hole that opens upstream at the upper surface of the long nozzle and downstream at the lower end of the long nozzle. Similarly, the collecting nozzle 14 has a collecting nozzle hole that opens upstream at the upper surface of the collecting nozzle and downstream at the lower end of the collecting nozzle. As is well known in the art, the collecting nozzle is much shorter than the ladle long nozzle such that when the ladle is in the casting position, the lower end of the collecting nozzle is far from the tundish and can be easily accessed by a cleaning tool 19r such as a rod or a pressurized gas lance. The drawer is movably mounted so as to translate the upper surface of the long nozzle and the upper surface of the collecting nozzle along the nozzle sliding surface of the lower plate 15d between the following positions:

[0125] · The long nozzle position, where the long nozzle hole is in fluid communication with the lower hole

[0126] · The collecting nozzle position, where the collecting nozzle hole is in fluid communication with the lower hole, and preferably,

[0127] · The sealed position, where the downstream end of the lower hole is sealed and is not in fluid communication with either the ladle hole or the collecting nozzle hole.

[0128] The sealed position of the drawer 15w is preferred but not essential since the flow from the ladle can be stopped by moving the lower hole of the lower plate out of alignment with the upper hole of the upper plate. Like the lower plate, the drawer 15w can be moved translationally by activating the drawer drive device 17w. The drawer drive device can include a cylinder 17c rigidly and reversibly coupled to the bottom of the first ladle or the second ladle 11, 12, and a piston 17p reversibly fixed to the drawer 15w. For example, the drawer drive device 17w can be a hydraulic piston or a pneumatic piston. Actuating the drawer drive device 17w allows the drawer 15w to be moved to align and misalign the long nozzle hole and the collecting nozzle hole with the lower hole.

[0129] Figure 2(a) to Figure 2(d) Shows the various steps for initiating a casting operation from ladles 11, 12 to tundish 1 through a ladle slide gate according to the first embodiment. Fig. 2(a) shows the new ladles 11, 12 that have reached the casting station. The ladle slide gate is in the sealed position, where the lower hole of the lower plate 15d is not aligned with the upper hole of the upper plate 15u. The inner hole and the upper hole of the submerged nozzle 18 are filled with a plugging material 19, which can be sand or any other particulate material, to prevent the sliding mechanism from being frozen by solidified metal. The drawer 15w can be positioned at the long nozzle position, where the long nozzle hole is in fluid communication with the lower hole. Since the downstream end of the upper hole is sealed by the lower plate, metal is not allowed to flow through the ladle. In this document, upstream and downstream are defined according to the expected flow direction of the molten metal. Once the ladle is at the casting station, casting can begin.

[0130] As shown in Fig. 2(b), to start casting, the drive device 17 translates the lower plate and the ladle long nozzle until the lower hole and the ladle hole are in fluid communication with the upper hole, thereby forming a continuous flow path from the inner hole to the long nozzle hole. Under normal circumstances, driven by the pressure of the molten metal in the ladle, the plugging material 19 flows out through the lower hole and the long nozzle hole. Once the plugging material 19 is discharged, the molten metal flows out of the ladle through the long nozzle hole. This operation takes a few seconds, and casting from the tundish to the tool can be carried out continuously. However, in some cases, the plugging material may form solidified lumps due to molten metal seeping through it and solidifying, thereby forming adhesions between the particles of the plugging material 19. Depending on the size and resistance of such solidified lumps, this may cause blockage of the inner hole and the upper hole, and no molten metal can flow out of the ladle. This situation is more precisely an abnormal situation compared to the conventional situation, but once it occurs, it will bring serious problems to the casting operation. For this reason, many operators are not willing to fix the ladle long nozzles 13a - 13c to the ladle slide gate 15, but rather prefer to use a robot to hold the ladle long nozzles in place when the ladle is at the casting station. With the ladle slide gate 15 according to this embodiment, even if the ladle long nozzles 13a - 13c are fixed to the drawer 15w as described below, the blocked inner hole and / or upper hole can be cleared very quickly.

[0131] As shown in Fig. 2(c), the drawer drive device 17w translates the drawer 15w so that the collection water inlet 14 is in fluid communication with the lower hole and the upper hole. Since the collection water inlet is much shorter than the ladle long nozzle, there is sufficient clearance above the tundish, so it is easy to introduce the dredging tool 19r to pass through the downstream end of the collection water inlet, through the upper hole and the lower hole until the inner hole. The dredging tool can be a metal rod, which can be used to break the solidified mass by hitting the solidified plugging material. Alternatively, the dredging tool 19r can be a pressurized gas spray gun that jets a pressurized gas jet such as oxygen. The dredging tool 19r can be operated manually or by a robot.

[0132] Once the solid mass breaks, the particles of the plugging material 19 begin to flow out through the collection water inlet, and as shown in Fig. 2(d), casting can start normally. The drawer 15w can be translated so that the ladle hole is in fluid communication with the lower hole, the upper hole, and the inner hole to start the casting operation. If the drawer includes a sealing position as defined above between the collection water inlet position and the ladle position, the lower plate 15d does not need to be moved when translating the drawer 15w. If the sealing position is not included, the lower plate 15d can be moved to the sealing position before moving the drawer between the collection water inlet position and the ladle position.

[0133] In Figure 3(a) to Figure 3(d) In the second embodiment shown, the lower plate 15d includes a first hole and a second hole, each of which extends from the top sliding surface to the nozzle sliding surface. The lower plate 15d is slidably mounted so that the top sliding surface can slide along the bottom sliding surface to put each of the first hole and the second hole in fluid communication with and out of fluid communication with the upper hole. The nozzle surface is configured to be rigidly and reversibly coupled to the ladle long nozzle 13a - 13c, where the ladle hole is in fluid communication with the first hole, and the collection water inlet hole is in fluid communication with the second hole. The ladle long nozzle 13a - 13c and the collection water inlet. In this second embodiment, the nozzle sliding surface of the lower plate 15d does not have any sliding function. During the entire casting operation from the ladles 11, 12 to the tundish 1, the ladle long nozzle 13a - 13c and the collection water inlet 14 are fixed relative to the lower plate 15d and remain aligned with the first hole and the second hole respectively.

[0134] Figure 3(a) to Figure 3(d)Shows the various steps for initiating the casting operation from the ladles 11, 12 to the tundish 1 through the ladle slide gate according to the second embodiment. Fig. 3(a) shows the new ladles 11, 12 that have reached the casting station. The ladle slide gate is in the sealed position, where neither the first and second holes of the lower plate 15d are aligned with the upper hole of the upper plate 15u. As in the first embodiment, the inner hole and the upper hole of the submerged nozzle 18 are filled with a plugging material 19, which can be sand or any other particulate material, to prevent the sliding mechanism from being frozen by the solidified metal. Since the downstream end of the upper hole is sealed by the lower plate, neither the molten metal 2 nor the plugging material 19 is allowed to flow through the ladle. Once the ladle is at the casting station, the casting can begin.

[0135] As shown in Fig. 3(b), to start the casting, the driving device 17 translates the lower plate and the ladle long nozzle 13a - 13c until the first hole and the ladle hole are in fluid communication with the upper hole, thereby forming a continuous flow path from the inner hole to the long nozzle hole. Under normal circumstances, driven by the pressure of the molten metal in the ladle, the plugging material 19 flows out through the lower hole and the long nozzle hole. Once the plugging material 19 is discharged, the molten metal flows out of the ladle through the long nozzle hole. This operation takes a few seconds, and the casting from the tundish to the tool can be carried out continuously. However, as discussed with respect to the first embodiment, in some cases, the solidified lumps of the plugging material 19 may block the inner hole and the upper hole, preventing the molten metal from flowing out of the ladle, and the passage must be cleared. With the ladle slide gate 15 according to the present embodiment, even if the ladle long nozzle 13a - 13c is fixed to the lower plate 15d as described below, the blocked inner hole and / or upper hole can be cleared very quickly.

[0136] As shown in Fig. 3(c), the driving device 17 translates the lower plate 15d so that the second hole and the collecting nozzle 14 are in fluid communication with the upper hole. Since the collecting nozzle is much shorter than the ladle long nozzle, there is enough clearance above the tundish, so it is easy to introduce a clearing tool 19r to pass through the downstream end of the collecting nozzle, through the upper hole and the lower hole and up to the inner hole. The clearing tool can be a metal rod or a pressurized gas spray gun, and they can be used to clear the passage, as discussed with respect to the first embodiment. The clearing tool 19r can be manually or robotically manipulated.

[0137] Once the solid lumps are broken, the particles of the plugging material 19 begin to flow out through the collecting nozzle, and as shown in Fig. 3(d), the casting can start normally. The lower plate 15d can be translated so that the first hole and the ladle hole are in fluid communication with the upper hole and the inner hole to start the casting operation.

[0138] In all embodiments of the ladle slide gate 15, the drive device 17 can be actuated hydraulically or pneumatically or electrically. Each of at least the first holding device and the second holding device of the ladle turntable is preferably provided with a pressurized fluid source for actuating the drive device 17 and for actuating the drawer drive device 17w (in the case of including the drawer 15w) via the hose 17t. In a preferred embodiment, each of at least the first holding device and the second holding device of the ladle turntable further includes a storage unit for storing the drive device 17 and the drawer drive device 17w (in the case of the presence of the drawer 15w) when the (drawer) drive device 17 is not connected to the ladle slide gate 15, as shown in FIGS. 1(a), 1(b) and 1(f). The (drawer) drive devices 17, 17w can also be stored in a storage rack on the loading platform. However, preferably, they are stored on the first holding device and the second holding device, because in this way, the drive devices 17, 17w can be permanently connected to the hydraulic or pneumatic fluid source 17h via the hose 17t. This enables the robot 21 not to have to perform the complex operation of connecting the hose 17t to the most recently connected (multiple) drive devices 17, 17w, which is a must when the drive devices 17, 17w are stored in the storage rack 29 on the loading platform.

[0139] Method for casting molten metal

[0140] The present invention also relates to a method for casting molten metal 2 from ladles 11, 12 into the tundish 1 in a casting apparatus as discussed above, wherein the first ladle 11 is filled with molten metal and is located at the casting station, while the second ladle 12 is filled with molten metal and is located at the loading station. As shown in FIG. 1(a), the ladle slide gate 15 of the first ladle 11 is in the sealed position and is provided with ladle long nozzles 13a - 13c and a collecting nozzle 14. The lower plate 15d of the ladle slide gate is connected to the drive device 17. If the ladle slide gate 15 is of the type including the drawer 15w as described in the first embodiment above, the drawer is connected to the drawer drive device 17w. The ladle slide gate 15 of the second ladle 12 is in the sealed position and does not include ladle long nozzles. The ladle slide gate 15 of the second ladle 12 is not connected to any (drawer) drive devices 17, 17w.

[0141] To start casting molten metal from the first ladle 11 through the ladle long nozzle 13a into the tundish 2, the ladle slide gate 15 of the first ladle 11 is moved into the casting position. This operation is carried out by actuating the drive device 17. The first ladle 11 discharges the molten metal 2 contained therein into the tundish 1 until the first ladle is considered emptied.

[0142] While the first ladle 11 is discharging its contents into the tundish, the robot 21 loads the new ladle long nozzle 13b onto the ladle slide gate 15 of the second ladle 12 (see FIG. 1(b)). As shown in FIG. 1(c), the robot 21 also couples the drive unit 17 and optionally the drawer drive unit 17w to the slide plate nozzle mechanism 15 of the second ladle 12. As discussed above, this operation becomes simpler if the first and second holding devices of the turntable 30 are provided with storage units for storing one or more (drawer) drive units 17, 17w, since during the entire casting operation involving emptying several (more than two) ladles into the tundish, the one or more (drawer) drive units can thus remain coupled to the pressurized fluid source 17h via the hoses 17t. If the one or more (drawer) drive units 17, 17w are stored elsewhere, typically in the storage rack 29 located on the loading platform 20, the robot 21 must additionally couple one or more hoses 17t to the corresponding one or more (drawer) drive units to make them operative. During the entire operation on the second ladle 12, the ladle slide gate remains in the sealed position.

[0143] As shown in FIG. 1(d), when the first ladle is substantially empty, the ladle slide gate 15 of the first ladle 11 is moved from the casting position into the sealed position to interrupt any flow of molten metal from the first ladle 11. The positions of the first ladle and the second ladle 11, 12 are exchanged by moving the first ladle 11 from the casting station to the loading station and concomitantly moving the second ladle 12 from the loading station to the casting station. The exchange of the positions of the first ladle and the second ladle 11, 12 can be carried out as follows. FIG. 1(d) shows how the turntable 30 can lift the first ladle and the second ladle 11, 12 until the ladle long nozzles 13a, 13b of the first ladle and the second ladle have both cleared the tundish and are vertically above the tundish in the vertical direction Z, thereby defining the rotation height. Thus, the turntable can be rotated without any risk of the ladle long nozzles 13a, 13b of the first ladle or the second ladle 11, 12 colliding with the tundish or any other components of the casting equipment. FIG. 1(e) shows the turntable rotating 180° about the vertical axis Z so that the emptied first ladle 11 is above the loading station and the filled second ladle 12 is above the casting station and above the tundish 2. During the rotation operation, the first ladle and the second ladle always remain at their rotation height. At this stage, the first ladle and the second ladle 11, 12 can be lowered to their respective loading and casting stations, and the ladle long nozzle 13b of the second ladle is inserted into the tundish 2.

[0144] The ladle slide gate 15 of the second ladle 12 can be moved to the casting position so that the molten metal can flow from the second ladle 12 through the ladle long nozzle 13b into the tundish 2. The entire exchange operation from closing the ladle slide gate of the first ladle 11 to opening the ladle slide gate of the second ladle 12 can last less than 2 minutes, preferably less than 1 minute, more preferably less than 30 seconds, and the liquid level of the molten metal in the tundish can be easily restored to a fixed casting level.

[0145] Now, the ladle long nozzle of the emptied first ladle 11 parked at the loading station can be stripped to allow its removal and transportation across the workshop to a refurbishment station (not shown). The used ladle long nozzle 11a can be removed from the ladle slide gate 15 of the emptied first ladle 11 by a robot 21. As shown in FIG. 1(f), the used ladle long nozzle 13a can be stored for refurbishment and cleaning (not shown) or stored as waste in a waste bin 27.

[0146] As shown in FIG. 1(f), the robot 21 can also disconnect and remove the one or more (drawer) drive devices 17, 17w from the slide gate mechanism 15 of the first ladle 11 and store the one or more (drawer) drive devices for further use. If the first holding device and the second holding device of the turntable 30 are provided with storage units for storing the one or more (drawer) drive devices 17, 17w, the robot 21 does not need to disconnect the corresponding one or more hoses 17t before storing the one or more drive devices because the hydraulic or pneumatic fluid source 17h or the power source is also located on the first holding device and the second holding device. On the other hand, if the one or more drive devices 17, 17w are stored in a storage rack 29 located on the loading platform 20, the robot must also disconnect the one or more hoses 17t from the corresponding one or more (drawer) drive devices 17, 17w before storing the one or more (drawer) drive devices in the storage rack 29. This is also the case if the (drawer) drive device has to be replaced due to a defect.

[0147] The emptied first ladle with the stripped ladle long nozzle 13a and the one or more (drawer) drive devices 17, 17w can be removed from the first holding device by a crane to a refurbishment station (not shown), where the ladle can be cleaned, repaired, and prepared to be filled with a new load of molten metal from the furnace. A new ladle filled with molten metal can be loaded onto the currently idle first holding device of the ladle turntable 30 at the loading station, where, like the second ladle 12 in step (a), the new ladle includes a ladle slide gate 15 in the sealed position but does not include ladle long nozzles 13a - 13c and (drawer) drive devices 17, 17w. Thus, the process can be repeated. Figure 1(a) to Figure 1(f)The depicted cycle, and the casting from the tundish to the tool can be carried out continuously, wherein during the entire continuous casting operation, the level of the molten metal in the tundish is substantially constant, and the fluctuations in the molten metal level when defining the positions of the emptied ladle 11 and the filled ladle 12 in step (e) are very small. The fluctuations can be very small because, when operating in an optimal manner, the exchange operation is very rapid.

[0148] If step (e) of exchanging the positions of the first ladle and the second ladle is not carried out optimally due to the inner hole and / or the upper hole being blocked by solidified plugging material, the ladle slide gate 15 including both the side-by-side ladle long nozzles 13a - 13c and the collecting nozzle 14 allows for the rapid and effective dredging of the inner hole and / or the upper hole by using an appropriate dredging tool 19r to pass through the collecting nozzle hole, as described above in the subsection titled "Ladle Slide Gate 15". In this way, the interruption of the metal flow into the tundish is minimized. Without this option of rapid dredging through the collecting nozzle hole, many operators are reluctant to fix the ladle long nozzles 13a - 13c to the bottom of the ladle at the loading station, with or without the robot 21, because dredging the inner hole and the upper hole in the case of fixing the ladle long nozzles to the ladle slide gate requires returning the blocked ladle to the loading station, replacing the ladle long nozzles with the collecting nozzle to allow dredging with the dredging tool 19r, and then reconnecting the ladle long nozzles and returning the ladle to the casting station. All these operations would take too long and there is a risk of metal freezing, which should be prevented by using plugging material. In addition, not feeding molten metal to the tundish for a long time may cause an interruption of the casting operation, which must be avoided by all means.

[0149] In a preferred embodiment, the loading operation of the second ladle 12 staying at the loading station is carried out in the following order: (1) Connect the (multiple) (drawer) drive devices to the ladle slide gate 15, and then connect the new ladle long nozzle 13b. Preferably, the unloading operation of the emptied first ladle 11 staying at the loading station is carried out in the following order: (1) Disconnect the used ladle long nozzle 13b, and then disconnect the (multiple) (drawer) drive devices from the ladle slide gate 15.

[0150] The present invention provides an automatic metal casting device, wherein, compared with a conventional metal casting device, a fresh ladle can be prepared by the robot 21 at the loading station for casting without any additional risk of interrupting the casting in the tool.

[0151]

[0152]

Claims

1. A metal casting device, comprising: A loading platform (20), A tundish (1), A first ladle (11) and a second ladle (12), each of the first ladle and the second ladle comprising: A bottom plate provided with an opening (11o, 12o), A collecting nozzle (14) and a ladle long nozzle (13a - 13c), A ladle sliding gate (15) configured to reversibly receive and support the collecting nozzle and the ladle long nozzle and further configured to be coupled to a driving device (17) for driving the ladle sliding gate between a sealing position, a casting position, and a dredging position, wherein in the sealing position, the opening is sealed, in the casting position, the opening is in fluid communication with the ladle long nozzle (13a - 13c), and in the dredging position, the opening is in fluid communication with the collecting nozzle (14), A turntable (30) that at least includes a first holding device and a second holding device for respectively holding the first ladle (11) and the second ladle (12), wherein the turntable is configured to move and hold in place the first ladle and the second ladle (11, 12) between a loading station adjacent to the loading platform (20) and a casting station above the tundish (1), Characterized in that the metal casting device includes a robot (21) configured to perform the following operations on the first ladle or the second ladle (11, 12) held at the loading station: Loading a new ladle long nozzle (13b) onto the ladle sliding gate (15), and Coupling the driving device (17) to the ladle sliding gate (15).

2. The metal casting equipment according to claim 1, characterized in that: The loading platform (20) includes a storage rack (29) that contains one or more spare ladle long nozzles (13b, 13c) within the reach of the robot (21).

3. The metal casting equipment according to claim 2, characterized in that: The storage rack further includes one or more driving devices (17) and / or spare collecting nozzles (14).

4. The metal casting equipment according to claim 2, characterized in that: The robot (21) is movably mounted on the loading platform (20) such that the robot can translate parallel to a first axis X or a second axis Y perpendicular to the first axis X, or translate in a combination of translating parallel to the first axis X and translating parallel to the second axis Y, and / or rotate about a vertical axis Z perpendicular to the first axis X and the second axis Y so as to reach the storage rack (29) and retrieve any tools or components therefrom and reach the ladle sliding gate of the first ladle or the second ladle (11, 12) held at the loading station to perform the operations defined in claim 1.

5. The metal casting equipment according to any one of claims 1-4, characterized in that: The robot (21) is configured to remove from the emptied first ladle or second ladle (11, 12) after moving from the casting station and being held at the loading station: The ladle long nozzles (13a - 13c), and The driving device (17).

6. The metal casting equipment according to claim 1, characterized in that: The ladle sliding gate (15) includes: Upper plate (15u), the upper plate comprising: A fixed surface and a bottom sliding surface, the fixed surface and the bottom sliding surface being spaced apart from each other by a distance equal to the thickness of the upper plate, An upper hole, the upper hole extending from the fixed surface to the bottom sliding surface, and wherein The fixed surface of the upper plate is rigidly fixed to the lower part of a corresponding first ladle or second ladle (11, 12), wherein the upper hole is in fluid communication with the opening; Lower plate (15d), the lower plate comprising: A nozzle sliding surface and a top sliding surface, the nozzle sliding surface and the top sliding surface being spaced apart from each other by a distance equal to the thickness of the lower plate, A lower hole, the lower hole extending from the top sliding surface to the nozzle sliding surface, wherein The lower plate (15d) is slidably mounted such that the top sliding surface can slide translationally along the bottom sliding surface to bring the lower hole into and out of fluid communication with the upper hole; and wherein A drawer (15w), the drawer being configured to rigidly hold a ladle long nozzle (13a - 13c) and a collecting nozzle (14), the ladle long nozzle having a long nozzle hole open at the long nozzle upper surface, the collecting nozzle having a collecting nozzle hole open at the collecting nozzle upper surface, the drawer being movably mounted so as to translate the long nozzle upper surface and the collecting nozzle upper surface along the nozzle sliding surface of the lower plate (15d) between a long nozzle position and a collecting nozzle position, at the long nozzle position, the long nozzle hole being in fluid communication with the lower hole, and at the collecting nozzle position, the collecting nozzle hole being in fluid communication with the lower hole; The drive device (17) is coupled to the lower plate (15d) to drive the translation of the lower plate; and A drawer drive device (17w) is coupled to the drawer (15w) to drive the translation of the drawer; Wherein, the drive device (17) is coupled to the lower plate (15d) and includes a cylinder (17c) and a piston (17p), the cylinder being rigidly and reversibly coupled to the bottom of a corresponding first ladle or second ladle (11, 12), the piston being rigidly and reversibly fixed to the lower plate (15d), the drive device being configured to move the lower plate to align or misalign the lower hole with the upper hole, and Wherein, the drawer drive device (17w) is coupled to the drawer (15w) and includes a cylinder (17c) and a piston (17p), the cylinder being rigidly and reversibly coupled to the bottom of a corresponding first ladle or second ladle (11, 12), the piston being rigidly and reversibly fixed to the drawer (15w), the drawer drive device being configured to move the drawer to align or misalign the long nozzle hole and the collecting nozzle hole with the lower hole.

7. The metal casting equipment according to any one of claims 1 to 4, characterized in that: The ladle slide gate (15) comprises: Upper plate (15u), the upper plate comprising: A fixed surface and a bottom sliding surface, the fixed surface and the bottom sliding surface being spaced apart from each other by a distance equal to the thickness of the upper plate, An upper hole, the upper hole extending from the fixed surface to the bottom sliding surface, and wherein The fixed surface of the upper plate is rigidly fixed to the lower part of the corresponding first ladle or second ladle (11, 12), wherein the upper hole is in fluid communication with the opening; A lower plate (15d), the lower plate comprising: A nozzle surface and a top sliding surface, the nozzle surface and the top sliding surface being spaced apart from each other by a distance equal to the thickness of the lower plate, A first hole and a second hole, each of the first hole and the second hole extending from the top sliding surface to the nozzle surface, wherein The lower plate (15d) is slidably mounted such that the top sliding surface can slide along the bottom sliding surface to bring each of the first hole and the second hole into and out of fluid communication with the upper hole, and wherein The nozzle surface is configured to be rigidly and reversibly coupled to the ladle long nozzle (13a - 13c) and the collecting nozzle, the ladle long nozzle having a ladle hole in fluid communication with the first hole, and the collecting nozzle having a collecting nozzle hole in fluid communication with the second hole, And wherein the drive device (17) is coupled to the lower plate (15d) and includes a cylinder (17c) and a piston (17p), the cylinder being rigidly and reversibly coupled to the bottom of the corresponding first ladle or second ladle (11, 12), the piston being rigidly and reversibly fixed to the lower plate (15d), the drive device being configured to move the lower plate to align or misalign the first hole and the second hole with the upper hole.

8. The metal casting equipment according to claim 1, characterized in that: The drive device (17) is hydraulically or pneumatically or electrically driven, and wherein each of at least the first holding device and the second holding device of the turntable is provided with: A pressurized fluid source for driving the drive device (17) via a hose (17t), or a power source.

9. The metal casting equipment according to claim 8, characterized in that: Each of at least the first holding device and the second holding device of the turntable is provided with: A storage station for storing the drive device (17) ready to be coupled to the ladle slide gate.

10. The metal casting equipment according to claim 1, characterized in that: The metal casting equipment includes a preheating furnace (25) for bringing a new ladle long nozzle (13b) loaded on the ladle slide gate (15) of the first ladle or second ladle (12) located at the loading station to and maintaining it at a preheating temperature.

11. The metal casting equipment according to claim 1, characterized in that: The robot is further configured to: Inspect the condition of the used ladle long nozzle after the used ladle long nozzle (13a - 13c) is removed from the emptied ladle, Evaluate whether the used ladle long nozzle can be reused after cleaning or must be discarded, and Clean the used ladle long nozzle with an oxygen sprayer to remove all residues adhering to the walls of the used ladle long nozzle.

12. A method for casting molten metal, comprising the steps of: a. Providing the metal casting equipment according to any one of claims 1 - 11, wherein The first ladle is filled with molten metal (2) and is at the casting station, and The second ladle (12) is filled with molten metal (2) and is at the loading station, The ladle slide gate (15) of the first ladle (11) is in the sealed position, coupled to one or more drive devices (17) or drawer drive devices (17w), and is provided with ladle long nozzles (13a - 13c) and a collecting nozzle (14). The ladle slide gate (15) of the second ladle (12) is in the sealed position but does not include ladle long nozzles (13a - 13c) and an operating drive device (17) and an operating drawer drive device (17w). b. Move the ladle slide gate (15) of the first ladle (11) to the casting position so as to cast molten metal from the first ladle (11) through the ladle long nozzle (13a) into the tundish (1). c. During the previous step, load a new ladle long nozzle (13b) onto the ladle slide gate (15) of the second ladle (12) using the robot (21), and couple the drive device (17) to the ladle slide gate (15) of the second ladle (12) using the robot (21). d. When the first ladle is substantially empty, move the ladle slide gate (15) of the first ladle (11) to the sealed position, and then e. Exchange the positions of the first ladle and the second ladle by moving the first ladle (11) from the casting station to the loading station and concomitantly moving the second ladle (12) from the loading station to the casting station. f. Move the ladle slide gate (15) of the second ladle (12) to the casting position and cast molten metal from the second ladle (12) through the ladle long nozzle (13b) into the tundish (1).

13. The method according to claim 12, characterized in that: During step f, the following steps are included: g. Remove the used ladle long nozzle (11a) from the ladle slide gate (15) of the emptied first ladle (11) using the robot (21), and store the used ladle long nozzle for refurbishment or as waste, and h. Disconnect and remove the one or more drive devices (17) from the ladle slide gate (15) of the first ladle (11) using the robot (21), and store the one or more drive devices for further use. i. Remove the emptied first ladle (11), and j. Load a new ladle filled with molten metal onto the first holding device of the turntable (30) at the loading station, wherein, like the second ladle (12) in step a, the new ladle includes a ladle slide gate (15) in the sealed position but does not include ladle long nozzles (13a - 13c).

14. The method according to claim 12 or 13, characterized in that: The opening of the first ladle is filled with a plugging material (19), and if no molten metal flows out of the opening when the ladle slide gate (15) of the first ladle (11) is moved to the casting station in step b, the following steps are performed: Move the ladle slide gate (15) of the first ladle (11) to the unclogging position. Unclog the opening of the first ladle by using an appropriate unclogging tool (19r) to break the clogging material. When the clogging material begins to flow out of the collecting nozzle, move the ladle slide gate (15) of the first ladle (11) into the casting position so as to cast the molten metal from the first ladle (11) through the thus unclogged opening and through the ladle long nozzle (11a) into the tundish (1).

15. The method according to claim 12, wherein: Step e of exchanging the positions of the first ladle and the second ladle includes the following steps: Lift the first ladle and the second ladle (11, 12) until the ladle long nozzles (13a, 13b) of the first ladle and the second ladle both leave the tundish and are above the tundish in the vertical direction Z. Rotate the turntable 180° about the vertical axis Z so that the first ladle (11) is above the loading station and the second ladle (12) is above the casting station and above the tundish (1). Lower the first ladle and the second ladle (11, 12) to their respective loading stations and casting stations, and insert the ladle long nozzle (13b) of the second ladle into the tundish (1).

16. The method according to claim 12, wherein: The robot also: Check the state of the used ladle long nozzle after the used ladle long nozzle (13a - 13c) is removed from the emptied ladle. Evaluate whether the used ladle long nozzle can be reused after cleaning or must be discarded, and Clean the used ladle long nozzle with an oxygen sprayer to remove all residues adhering to the walls of the used ladle long nozzle.

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