Equipment for producing metals

Abstract

An apparatus for producing metal comprises a melting furnace (11) for melting metal, the melting furnace (11) being provided with a crucible (12) in which a metal charge is melted. The melting furnace (11) is provided with a device (14) for discharging liquid metal, the device (14) being arranged at the bottom of the crucible (12) and comprising a tapping channel (15) for transferring liquid metal from the melting furnace (11). The apparatus further comprises a delivery unit (16) for delivering an inert material (S), the delivery unit (16) comprising a delivery device (17) for selectively delivering the inert material (S) into the tapping channel (15).

Description

Technical Field

[0001] The present invention relates to an apparatus for producing metal comprising a furnace and means for selectively conveying an inert particulate material, preferably characterized by a high melting temperature within the furnace. Background Art

[0002] As is known, equipment for producing metallic materials includes a furnace, such as an electric arc furnace, which is provided with at least one metal container, referred to as a shell, which is lined with a heat-resistant material capable of withstanding high temperatures and is suitable for containing liquid metal produced by melting. The entire metal container together with the heat-resistant substrate is referred to as a "crucible."

[0003] The furnace also includes a covering dome or plate, which may have holes for the electrodes that enter the crucible to generate the arc, as well as one or more holes for extracting the fumes. At the bottom or side of the crucible, there is usually a device to remove the liquid metal from the crucible into another container, usually called a "ladle", so that it can be transported to the next processing plant. This operation is usually called "tapping".

[0004] A known solution is to arrange the tapping holes at discrete locations relative to the center of the furnace, a process known as "eccentric bottom tapping (EBT)." To facilitate the transfer of liquid metal from the crucible to a transport container for the next step in the process, a device is used to rotate the furnace, allowing it to pivot horizontally to facilitate pouring the liquid metal. The tapping channel for the outflowing liquid metal is opened by an aperture in a mechanical device that closes the tapping hole.

[0005] After the step of removing the liquid metal produced in the cycle and before the metal charge of the next cycle is introduced into the furnace, the tapping channel is gradually filled with a certain amount of inert granular material, which is characterized by being resistant to high temperatures and being sintered to a limited thickness in contact with the liquid metal to form a continuous plug in order to prevent the liquid metal from flowing into the tapping channel and destroying its mechanical closing device, or preventing the liquid metal from solidifying therein and blocking the tapping channel.

[0006] These operations are almost all performed manually by dedicated personnel.

[0007] Above the furnace's tapping channel, a cooling cover plate is equipped with an inspection port. Once the operation of transporting liquid metal is completed, the furnace is rotated backward to interrupt the flow of liquid metal to the inspection port. Workers approach the cover plate and visually inspect the tapping channel through its holes, where it is naturally exposed to thermal radiation from the furnace and to the impact of gases emitted by the crucible itself. Furthermore, in this case, the cover plate is tilted and is often covered by various materials projected there by the melting and charging operations, creating multiple risks to operator safety.

[0008] If the tapping channel is partially or completely blocked by residues that prevent free access, manual removal is necessary. Oxygen injection is often used to melt these residues and allow free access to the tap hole. In the prior art, these operations required the use of relatively large tools and oxygen pipes. To facilitate tool operation and limit risks to personnel, it was necessary to provide adequate maneuvering space.

[0009] In order to prevent personnel from having to perform manual operations, devices are known that fill the tap hole with an inert granular material as above, which is characterized by a high melting temperature.

[0010] Generally speaking, these filling devices are stably attached to the covering plate of the eccentric part of the crucible (US Pat. No. 9,920,995 B2) or to the dome of the furnace (KR 101330306 B1) and are integral with the latter during all the operating steps of metal production.

[0011] One of the drawbacks of these devices is that if the operations of cleaning the crucible area and the tapping channel as described above have to be carried out, close to the cover plate, there are great operational risks for the maintenance personnel, considering the large volumes and space limitations imposed by the devices described in the teachings of the prior art.

[0012] In the event of malfunctions and breakdowns of installed equipment, maintenance and repair work is extremely difficult to carry out, also due to potential internal factors, so that the equipment almost always needs to be dismantled. This results in extended maintenance times, increased complexity of the operations to be performed, and high risks for specialized personnel.

[0013] The aforementioned U.S. Patent No. 9,920,995 B2 describes a system for conveying sand into a furnace, wherein the system is stably attached to the furnace and substantially integral with the furnace. The sand conveying system described in US Pat. No. 9,920,995 B2 includes a tank for storing sand, an upper panel that closes an aperture formed in a cover plate of the crucible, and a discharge conveyor serving as a correction port. The discharge conveyor is attached to the upper panel so as to have a lower end extending into the furnace and an opposite upper end located outside the furnace. The first end of the discharge conveyor is capable of being aligned with the tapping port to allow for directed and cohesive delivery of sand into the tapping channel.

[0014] The storage tank is movable between a first position remote from the upper end of the discharge conveyor and a second position adjacent the lower end of the discharge conveyor to deliver a predetermined amount of sand into the discharge conveyor and thereby into the tapping channel.

[0015] The storage tank is attached to and moves about the upper panel, defining a single unit attached to the cover plate above the tap channel. This can be an obstacle if intervention is necessary to resolve a furnace problem or a sand delivery system failure.

[0016] Another disadvantage of the system described in US 9,920,995 B2 is that during the step of melting the metal charge, in particular during the step of refining the liquid metal, the discharge conveyor can become blocked both by splashing of liquid metal onto the inner walls of the discharge conveyor and by slag which tends to solidify in contact with the walls of the discharge conveyor and / or with adjacent surfaces.

[0017] Therefore, it is often necessary to remove the metal layer and solidified slag inside the discharge conveyor before sand can be introduced to refill the taphole. This slows down production and creates risks for the operator who has to intervene to restore the correct function of the discharge conveyor.

[0018] Documents JP S60 176867 U 22, JP S61 167265 U 17, and JP S 58 134254 U 9 disclose further examples of conventional filling devices. The solutions described in these documents are limited to operation related to ladles, which are containers used to transport liquid metal to a solidification plant downstream of a furnace. Their geometry and operation differ significantly from the application under consideration, making it difficult to apply these solutions to furnace-related applications.

[0019] Therefore, a need exists for an improved apparatus for producing metals that overcomes at least one of the shortcomings of the prior art.

[0020] In particular, one object of the present invention is to provide a plant for producing metal which allows reducing the cycles of the furnace and above all of the cycles of delivering sand.

[0021] Another object of the present invention is to provide a plant for producing metal which allows delivering the correct amount of inert material into the tapping channel, regardless of the degree of wear and / or scaling of the latter.

[0022] Yet another object of the present invention is to provide an apparatus for producing metal that allows maintenance personnel to perform maintenance and repairs in an easy, fast, efficient and safe manner.

[0023] It is a further object of the present invention to provide an apparatus for producing metal that reduces the buildup and layering of metal and slag associated with the cover plate.

[0024] Yet another object of the present invention is to provide an apparatus for producing metal which allows safe access for visual inspection of the tapping channel and also allows easy introduction of an inert material stream without the inert material stream deviating from the tapping channel along its falling trajectory.

[0025] Yet another object of the present invention is to perfect the method of feeding an inert material, preferably granular and having a high melting temperature, into a furnace for producing metal, in order to periodically fill a tapping channel arranged on the bottom of the furnace.

[0026] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages. Summary of the Invention

[0027] The invention is set forth and characterized in the independent claims. The dependent claims describe further characteristics of the invention or variants to the main inventive idea.

[0028] According to the above purpose, an apparatus for producing metal that overcomes the limitations of the prior art and eliminates the defects therein comprises:

[0029] a furnace for melting metal, provided with a crucible in which a metal charge is melted, and a cover plate, the furnace being provided with a device for tapping the liquid metal, which device is arranged on the bottom of the crucible and comprises a tapping channel for conveying the liquid metal from the furnace to another container for conveying the liquid metal to a downstream process,

[0030] - a unit for delivering inert material, comprising at least one delivery device for selectively delivering inert material into the tapping channel,

[0031] a window unit arranged on the cover plate, the window unit being arranged above the tapping area, ie above the area of ​​the crucible bottom where the tapping channel is provided, and being configured to allow access therethrough to the crucible for delivering the inert material.

[0032] The unit for delivering the inert material comprises a supporting device configured to rotatably support the delivering device so as to transform the delivering device from an operational state, in which the delivering device faces the furnace and is aligned with the window unit, to a standby or parking state, in which the delivering device is arranged outside the main body of the furnace, and vice versa.

[0033] The possibility of freeing the movement of the delivery unit from the structure and cover plates of the furnace makes the system more flexible and allows to significantly simplify maintenance operations of the furnace and the delivery unit.

[0034] Furthermore, components involved in conveying the material are less likely to become fouled or scaled by spatter or metal particles from within the furnace.

[0035] According to one aspect, the apparatus as described above further comprises a slag crushing apparatus configured to crush the layer of slag and metal that may have settled on the upper inner wall of the furnace. The slag crushing apparatus comprises a window unit as described above or a special slag crushing device, or a combination of both.

[0036] A horizontally pivoting window unit selectively covers the holes in the furnace cover plate, allowing the same window unit to be used to operate to break up slag formed in the vicinity of the hole, release the slag and facilitate and speed up the filling cycle.

[0037] In cases where the window unit is not fully functional due to the geometry of the furnace, the above-mentioned slag breaking device allows to separately carry out or complete the breaking of the layer of slag and metal that forms on the upper inner wall of the furnace and hinders access for correct filling of the tapping channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] These and other characteristics of the invention will become apparent from the following description of some embodiments thereof, given as non-limiting examples with reference to the accompanying drawings, in which:

[0039] Figure 1 is a partial side view of an apparatus for producing metal according to some embodiments;

[0040] Figure 2 yes Figure 1 A top view of the delivery device in an operational state;

[0041] Figure 3 yes Figure 1 A top view of the delivery device in a standby or parked position;

[0042] Figure 4-Figure 6 Shown Figure 1 the possible sequence of operations of equipment used to produce metals;

[0043] Figure 7shows a side cross-sectional view of a delivery device;

[0044] Figures 8-10 shows a partially cutaway side view of a window unit, wherein the components are shown in different operating states;

[0045] Figure 11 shows a top view of the window unit;

[0046] Figure 12 is a partial side view of an apparatus for producing metal according to other embodiments described herein;

[0047] Figure 13 yes Figure 12 A side view of the delivery unit, wherein the rotational action of the slag crushing device is visible;

[0048] Figure 14-15 Shown Figure 12 possible operating sequences of equipment used to produce metals;

[0049] Figure 16 The operational steps for delivering inert material while the furnace is tilted are shown.

[0050] To facilitate understanding, identical reference numerals are used to identify identical common elements in the figures where possible. It should be understood that elements and features of one embodiment can be conveniently incorporated into other embodiments without further clarification. DETAILED DESCRIPTION

[0051] Reference will now be made in detail to possible embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of illustration of the present invention and is not to be construed as limiting the invention. For example, one or more features shown or described (so long as they are part of one embodiment) may be modified or employed in other embodiments, or employed in conjunction with other embodiments, to produce yet further embodiments. It is to be understood that the present invention encompasses all such modifications and variations.

[0052] Before describing the embodiments, it must be clarified that the application of this specification is not limited to the details of construction and arrangement of components described in the following description using the accompanying drawings. This specification may provide other embodiments and may be obtained or carried out in various other ways. It must also be clarified that the phraseology and terminology used herein are for descriptive purposes only and are not to be construed as limiting.

[0053] The exemplary embodiment described here relates to an apparatus for producing metal, which is designated by reference numeral 10 in the figures.

[0054] According to some embodiments, Figure 1-Figure 3As shown, an apparatus 10 for producing metal (hereinafter apparatus 10 ) comprises a furnace 11 for melting metal, the furnace 11 being provided with a holding vessel, in this particular example a crucible 12 , in which a metal charge is melted.

[0055] The melting furnace 11 is provided with a device 14 for tapping the liquid metal, which is arranged on the bottom of the crucible 12 and comprises a tapping channel 15 for extracting the liquid metal.

[0056] The melting furnace 11 includes a cover plate 13 arranged on an upper portion of the crucible 12 .

[0057] The apparatus 10 comprises a delivery unit 16 for selectively feeding inert material S into the tapping channel 15 .

[0058] The delivery unit 16 includes a delivery device 17 configured to selectively deliver a fixed amount of inert material into the tapping channel 15 through the window unit 18 arranged on the cover plate 13 of the furnace 11 as described above.

[0059] The delivery unit 16 further comprises means 19 for supporting the delivery device 17 .

[0060] In the specific example, the support device 19 comprises a base 20 stably attached to a mounting surface 100 outside the furnace 11. The mounting surface 100 may be, for example, a frame to which the furnace 11 is mounted and which allows it to pivot horizontally for tapping operations.

[0061] The support device 19 includes a movable base 21 that is stably attached to the base 20 and is configured to rotatably support the delivery device 17 so as to move the delivery device 17 from an operational state ( Figure 1-Figure 2 ) is brought to a standby or parking state, in which the delivery device 17 faces the furnace 11 and is aligned with the window unit 18. In the standby or parking state, the delivery device 17 is arranged outside the main body of the furnace 11 ( Figure 3 Since the delivery unit 16 is essentially independent of the furnace 11 and since it is not restrained in any way, the delivery device 17 can be rotated in the standby or parked state, for example in the event that maintenance interventions must be carried out in the furnace 11 or if the furnace 11 must be lifted up using a bridge crane. Obviously, an advantage also arises when maintenance interventions must be carried out on the delivery unit 16, since the operator can intervene safely by being away from the furnace 11. In the standby or parked state, the delivery device 17 is also completely protected from the heat of the furnace 11 or any flames that may emanate from it.

[0062] According to some embodiments, the apparatus 10 includes a slag crushing apparatus 30 configured to crush the layer of slag and metal that rests on the inner surface 27a of the access panel 27 ( Figure 8), or stays on the inner surface of the cover plate 13 during the operating steps of the furnace 11. This slag layer can prevent the correct filling of the tapping channel 15 and must therefore be removed.

[0063] The slag crushing apparatus 30 described herein may include its own window unit 18, or as Figure 12-15 The particular slag crushing device 55 shown, or may include both, will be described in more detail below.

[0064] According to some embodiments, the window unit 18 comprises a support plane 23 stably associated with the cover panel 13 and provided with an aperture 22 and a closing door 24 corresponding to the dimensions of the aperture 22 and configured to allow or prevent access to the aperture 22 , for example in the event that a maintenance intervention is necessary.

[0065] The holes 22 are aligned with corresponding channels 53 defined in the cover plate 13 ( Figure 1 and Figure 4-Figure 6 ).

[0066] The closing door 24 may include a cooling device 31 , such as a coil of tubing through which a cooling fluid can flow.

[0067] The window unit 18 includes a first pivoting device 25 to which the closing door 24 is rotatably associated for transitioning from the operating position to the maintenance position (eg, Figure 10 ), in the operational position the closing door 24 blocks access to the aperture 22 , and in the maintenance position the closing door 24 allows access to the aperture 22 .

[0068] A first pivoting device 25 may be associated with the supporting plane 23 .

[0069] The first pivot device 25 may be arranged corresponding to a terminal edge of the closing door 24 .

[0070] The first pivoting device 25 is rotatable along a first rotation axis X1 and is arranged in correspondence with the end edge of the closing door 24 closest to the delivery unit 16 .

[0071] The closing door 24 is provided with a central hole 26 and an access panel 27 configured to selectively (even only partially) open and close the central hole 26. The central hole 26 is generally vertically aligned with the steel tapping channel 15, which is located on the bottom of the crucible below the central hole 26. It is possible that the central hole 26 can be slightly offset from the steel tapping channel 15. Figure 16 As shown, in fact, the feeding of the inert material S is carried out when the furnace 11 is tilted. The central hole 26 is determined in such a way that, in the tilted configuration of the furnace 11, the feeding direction of the material S passes through the vertical direction of the upper opening of the steel tapping channel 15 (see, for example, FIG. Figure 7 43a and 43b).

[0072] The access panel 27 is configured to transition from a closed position, in which the access panel 27 is generally parallel to the closure door 24 and blocks access to the central aperture 26, to an open position (eg, Figure 8 ), the access panel 27 is inclined, for example orthogonal to the closing door 24 , to allow access to the central hole 26 for the introduction of the inert material S by the delivery device 17 .

[0073] according to Figure 5 and Figure 9 In the illustrated embodiment, the access panel 27 is tiltable relative to the closed position as described above, both toward the interior of the furnace 11 and toward the exterior of the furnace 11, possibly in an alternating manner, in order to break up layers of slag and metal that may have settled on the inner surface 27a of the access panel 27 during operating steps of the furnace 11. For example, prior to filling the tapping channel 15, the access panel 27 may be tilted in an alternating manner toward the interior of the furnace 11 and toward the exterior of the furnace 11 in order to break up layers of slag and metal as described above. Figure 5 and Figure 9 ).

[0074] The window unit 18 comprises a second pivoting device 28, and the access panel 27 is rotationally associated with the second pivoting device 28 so as to transition from the aforementioned closed position to the aforementioned open position, possibly via an intermediate tilted position, and towards the interior and / or exterior of the furnace 11 ( Figure 9-Figure 9 ).

[0075] The second pivoting device 28 may be arranged at an intermediate position between the end edges of the access panel 27. In this way, the vertical bulk of the access panel 27 may be limited and the force necessary to break up the layer of slag and metal formed on the inner surface 27a when the access panel 27 transitions from the closed position to the open position may be significantly reduced.

[0076] The second pivot device 28 is rotatable along a second rotation axis X2 that is substantially parallel to the first rotation axis X1 .

[0077] The second pivoting device 28 may comprise a pair of fixed peripheral elements, in this particular example a pair of bearings 28a, 28b, which are attached to the closing door 24 on one side and the other side relative to the central hole 26, and a fixed central element 28c (for example a lever or the like) which is stably attached to the access panel 27 ( Figure 2-Figure 3 , Figures 8-11 ).

[0078] The fixed peripheral element 28a and the central element 28c are associated with each other via a first pin 50. The fixed peripheral element 28b and the central element 28c are associated with each other via a second pin 51. The first pin 50 and the second pin 51 rotate about a second rotation axis X2.

[0079] The window unit 18 may include an actuation assembly 52 to operably control movement of the closure door 24 and the access panel 27 .

[0080] The actuation assembly 52 may include a first actuation device configured to move the closure door 24 and a second actuation device configured to move the access panel 27 .

[0081] The first actuating device and the second actuating device may be attached to the support plane 23 .

[0082] The first actuating means may be distinct and separate from the second actuating means.

[0083] according to Figure 8-Figure 9 In the embodiment shown, the actuation assembly 52 comprises, for example, an extendable arm 47 attached about a first end to the support plane 23 and about an opposite second end to a lever 49 associated with the second pivoting device 28. When the extendable arm 47 is actuated, it allows the lever 29 to rotate in order to move the access panel 27 from the closed position to the open position and vice versa, and to allow its alternating movement in order to break up the layers of slag and metal.

[0084] In the event that the closing door 24 has to be moved, the access panel 27 can clamp itself relative to the closing door 24 and allow the closing door 24 to be rigidly rotated from the closed position to the maintenance position and vice versa.

[0085] It is possible to operate the movement of the closing door 24 by means of a load-carrying and moving device (eg a bridge crane) which lifts the closing door in a rotatable manner via a hook or a lifting eye.

[0086] According to some embodiments, at least the access panel 27 may be made of copper or its alloys. The high thermal conductivity of copper allows for optimal dissipation of the heat generated in the furnace 11 during the metal production operation steps. Possibly, the access panel 27 may also be provided with a cooling circuit in order to improve and enhance heat exchange.

[0087] According to some embodiments, at least the inner surface 27a may be smooth and may be ground in order to limit as much as possible the possibility of slag and metal adhering thereto.

[0088] According to some embodiments, the delivery device 17 includes a fixed support structure 32 configured to slidably receive a movable storage and delivery structure 33 ( Figure 6 ).

[0089] The fixed support structure 32 is associated with the movable base 21. Specifically, the fixed support structure 32 is pivoted to the movable base 21 so as to preferably adjust the inclination of the delivery device 17 in the vertical plane. This allows the inert material flow to be directed to the tapping channel 15 even with a curved trajectory, for example a parabolic trajectory.

[0090] For this purpose, the fixed support structure 32 is hinged to the movable base 21 on a hinge device 34, which is arranged in a substantially central position below the fixed support structure 32. Adjustment means 35 (in this particular example a pair of arms, hydraulic or pneumatic) operatively connect the fixed support structure 32 to the movable base 21 so as to allow the delivery device 17 to rotate on the hinge device 34. The adjustment means 35 can be associated with the rear edge of the fixed support structure 32 and with the corresponding rear edge of the base 21 ( Figure 6 ).

[0091] The removable storage and delivery structure 33 comprises a storage chamber or tank 36 configured to contain the inert material S, a delivery device 37 selectively connected to the storage chamber 36 when the access panel 27 is in the open position and configured to introduce the inert material S through the central hole 26, and a control device 38 configured to verify that the tapping channel 15 is correctly filled after the filling step of the tapping channel or is configured to verify its correct operation function after the step of tapping the molten metal ( Figure 6 ).

[0092] The movable storage and delivery structure 33 further comprises a movable actuator 39 configured to allow or deny connection between the delivery device 37 and the storage chamber 36. The movable actuator 39 is operatively controlled by a mechanism 40 disposed within the movable storage and delivery structure 33. The movable actuator 39 allows the flow of the inert material S to be controlled in a precise and defined manner, in a continuous or intermittent manner, that is, according to a filling curve based on the dimensions of the tapping channel 15. The movable actuator 39 may be or comprise, for example, a shut-off valve ( Figure 7 ).

[0093] When the delivery device 17 is in the above-described operating state, the movable storage and delivery structure 33 is movable so as to be moved from the retracted position ( Figure 4 ) transition to the extended or delivery position ( Figure 6 ), in the retracted position, the delivery device 37 is positioned away from the center hole 26, and in the extended or delivery position, the delivery device 37 is positioned close to the center hole 26, for example aligned with or nearly aligned with the center hole 26, so as to deliver the inert material S into the steel outlet channel 15 through the center hole 26.

[0094] When the delivery device is in the above-mentioned standby or parked state, the movable storage and delivery structure 33 can be moved from the retracted state to the extended state, for example in order to allow the storage chamber 36 to be re-supplied with new inert material S.

[0095] The delivery device 17 comprises an actuator 41 (electrical, hydraulic or pneumatic) attached at the back about a first end to the fixed support structure 32 and at the front about an opposite second end to the movable storage and delivery structure 33, corresponding to the connection node 42 ( Figure 7 ).

[0096] The delivery device 37 comprises a delivery channel 43 provided with an advantageously funnel-shaped initial section 43a and a terminal section 43b of substantially constant portion. Possibly, the delivery device 37 may be inclined in order to define a correct flow trajectory of the inert material S.

[0097] According to some embodiments, the control device 38 may include a camera 44 or other suitable device at a position that is fixed or remotely adjustable and directed toward a control aperture 45 defined in the storage and delivery structure 33. The camera 44 may be disposed in a receiving compartment 46 defined in the front of the movable storage and delivery structure 33.

[0098] At the end of and / or before the step of filling the tapping channel 15 with inert material S, the movable storage and delivery structure 33 can be moved so as to align the camera 44 and thus the control hole 45 with the central hole 26 and thus with the tapping channel 15. During the cycle of filling the tapping channel 15 with inert material S, the camera 44 can even be used to visually inspect the tapping channel 15 at different times.

[0099] According to some embodiments, the movable base 21 can rotate along a vertical axis of rotation Z ( Figure 1 ) in order to bring the delivery device 17 from the operational state to the standby or parking state, and vice versa ( Figure 2-Figure 3 ).

[0100] The possibility of rotating the delivery device 17 into a position where it does not interfere with the cover plate 13 allows free access to the cover plate 13 when necessary and protects the device from the heat coming from the furnace 11 .

[0101] In a possible functional variant of the device 10, the delivery device 17 ( Figure 2 )'s rotational movement (possibly in combination with the above-described translational movement obtained by actuator 41) allows delivery device 17 to drop by gravity (e.g., from a storage hopper located above it through pipes and valves) into the appropriate position to load canister 36.

[0102] For this purpose, the delivery unit 16 comprises a drive device 54 configured to start / stop the movement of at least the movable substrate 21 ( Figure 1 ).

[0103] In the operating state, the delivery device 17 is generally aligned with the access panel 27, that is, with the central aperture 26. In this state, the movable storage and delivery structure 33 moves between a retracted or standby position and an extended or delivery position.

[0104] According to some embodiments, Figure 12-15 As shown, a slag crushing device 55 is associated with the delivery unit 16 and is provided with a slag crushing punch 56 configured to descend through the passage 53 and crush a slag layer that may form on the inner surface of the cover plate 13 .

[0105] The slag crushing punches 56 may be activated pneumatically, hydraulically, or electrically.

[0106] The slag crushing device 55 may be attached to the movable base 21 ( Figure 12-13 ), or a fixed support structure 32 attached to the delivery device 17. In both cases, the movement is the same, since the fixed support structure 32 moves integrally with the movable base 21.

[0107] Specific reference Figure 14-15 , the slag crushing device 55 is arranged laterally with respect to the delivery unit 16 .

[0108] The slag crushing device 55 is independently rotatable between an operating position, in which the slag crushing punch 56 is substantially perpendicular to the gap of the channel 53, and a standby position, in which the slag crushing punch 56 is tilted so as to limit its volume (if necessary), for example, to uncover the furnace 11 during the step of loading the furnace 11 ( Figure 13 ).

[0109] In the working position, the slag crushing punch 56 is substantially parallel to the vertical axis of rotation Z, whereas in the standby position the slag crushing punch 56 may be tilted, for example by approximately 45°.

[0110] The alignment of the slag crushing punch 56 (ie the operating axis along which it is raised and lowered) with the channel 53 is achieved by starting the rotation of the movable base 21 ( Figure 14-15 ).

[0111] When neither the delivery device 17 nor the slag crushing device 55 is needed, the movable base 21 rotates them sideways ( Figure 15 ).

[0112] The slag crushing device 55 is particularly useful if the cover plate 13 has a considerable thickness, for example to accommodate a cooling circuit therein, and the slag layer cannot be crushed by means of a rotational movement of the access panel 27 as has been described above.

[0113] In the presence of the slag crushing device 55, the window unit 18 may (even if not necessarily) have a simplified construction. For example, the access panel 27 would not have a tilting range for crushing the slag and could simply be openable and reclosable.

[0114] According to some embodiments, a method of producing metal in a furnace 11 as described above is provided. The method comprises at least one step of filling a tapping channel 15 of the furnace 11 with an inert material S.

[0115] According to one aspect of the present invention, a device 17 for delivering inert material S is supported by a support device 19 outside the furnace 11 and is rotatably movable, at least from a standby or parked state, in which the delivery device 17 is arranged outside the main body of the furnace 11, to an operational state, in which the delivery device 17 cooperates with the steel tapping channel 15, and vice versa. Specifically, in the operational state, the delivery device 17 is at least partially above the cover plate 13.

[0116] According to some embodiments, when the delivery device 17 is in the operating state as described above, the movable storage and delivery structure 33 is made to translate towards the window unit 18, in particular towards the access panel 27. Simultaneously, or just before, the method provides for moving the access panel 27 in order to gain access to the central hole 26 from which the inert material S is discharged towards the tapping channel 15.

[0117] According to some embodiments, access panel 27 may be rotationally moved in an alternating manner, toward the interior of furnace 11 and toward the exterior of furnace 11 , to break up layers of slag and metal that may reside on inner surface 27 a of access panel 27 .

[0118] According to a possible embodiment, the delivery device 17 can be rotationally moved into a loading state, which is different from the operational state and possibly also from the standby or parking state, in order to make the tank 36 available for loading / filling.

[0119] According to one embodiment, before the inert material S is discharged toward the tapping channel 15, the central hole 26 is controlled by an inspection device, and optionally, the slag crushing device 55 is driven to bring the slag crushing punch 56 into a position substantially perpendicular to the central hole and aligned with its central axis, and the slag crushing punch 56 is inserted through the central hole 26 in order to crush the existing slag layer.

[0120] Then, the slag crushing punch 56 is lifted to a parked position outside the furnace 11 and the delivery device 17 is repositioned in operation to discharge the inert material S.

[0121] The inspection operation can be accomplished through the central hole 26 or through the hole 22 , both of which are aligned with the channel 53 defined in the cover plate 13 .

[0122] The alignment of the slag crushing device 55 is operated by means of the support device 19 , in particular by means of the movable base 21 .

[0123] It is clear that modifications and / or additions of components may be made to the plant for producing metal described hereinbefore, without thereby departing from the field and scope of the present invention.

[0124] It is also clear that, although the invention has been described with reference to some specific examples, a person skilled in the art will certainly be able to realize many other equally effective forms of equipment for producing metal, having the characteristics recited in the claims and therefore falling within the field of protection defined therein.

[0125] In the following claims, references in parentheses are provided for reading convenience only; they are not to be construed as limiting the scope of protection claimed in a particular claim.

Claims

1. An apparatus for producing metal, comprising: - a furnace (11) for melting metal, said furnace (11) being provided with a crucible (12) in which a metal charge is melted and a cover plate (13) arranged on top, said furnace (11) being provided with a device (14) for tapping the liquid metal, said device (14) being arranged on the bottom of said crucible (12) and comprising a tapping channel (15) for conveying said liquid metal from the furnace (11), - a delivery unit (16) for delivering an inert material (S), the delivery unit (16) comprising a delivery device (17) for selectively delivering the inert material (S) into the steel tapping channel (15), the delivery unit (16) being characterized in that the delivery unit (16) comprises: a window unit (18) arranged on the cover plate (13) and configured to allow the inert material (S) to be delivered into the crucible (12) therethrough, - a supporting device (19) configured to rotatably support the delivery device (17) so as to bring the delivery device (17) from an operational state, in which the delivery device (17) faces the furnace (11) and is aligned with the window unit (18), to a standby or parking state, in which the delivery device (17) is arranged outside the body of the furnace (11), The window unit (18) comprises a support plane (23) stably associated with the cover plate (13) and provided with a hole (22) and a closing door (24) pivotally connected to the support plane (23) so as to allow or prevent access to the hole (22), the closing door (24) being provided with a central hole (26) and an access panel (27) pivotally connected to the closing door (24) so ​​as to selectively open and close the central hole (26).

2. The device according to claim 1, characterized in that The apparatus comprises a slag crushing apparatus (30) configured to crush a layer of slag and metal present on the upper inner wall of the furnace (11), and wherein the slag crushing apparatus (30) comprises its own window unit or slag crushing means (55) or both.

3. The device according to claim 1 or 2, characterized in that The support device (19) includes a base (20) and a movable base (21), wherein the base (20) is stably attached to a mounting surface (100) outside the furnace (11), and the movable base (21) is stably attached to the base (20) and is configured to bring the delivery device (17) from the operating state to the standby or parking state, and vice versa.

4. The device according to claim 1, characterized in that The access panel (27) is configured to transition from a closed position, in which the access panel (27) is parallel to the closing door (24) and blocks access to the central aperture (26), to an open position, in which the access panel (27) is tilted relative to the closing door (24) to allow access to the central aperture (26) for introduction of the inert material (S) via the delivery device (17).

5. The device according to claim 4, characterized in that The access panel (27) is tiltable relative to the closed position, both towards the interior and the exterior of the furnace (11).

6. The device according to claim 4, characterized in that The window unit (18) includes a second pivot arrangement (28) and the access panel (27) is rotationally associated with the second pivot arrangement (28) for transitioning from the closed position to the open position.

7. The device according to claim 6, characterized in that The second pivoting device (28) comprises a pair of fixed peripheral elements (28a, 28b) and a fixed central element (28c), the fixed peripheral elements (28a, 28b) being attached to the closing door (24) on one side and the other side relative to the central hole (26), the central element (28c) being attached to the access panel (27), the fixed peripheral elements (28a) and the central element (28c) being associated with each other by a first pin (50), and the fixed peripheral elements (28b) and the central element (28c) being associated with each other by a second pin (51) different from the first pin (50).

8. The device according to claim 6, characterized in that The window unit (18) includes an actuation assembly (52) for operatively controlling movement of the closure door (24) and the access panel (27).

9. The device according to claim 8, characterized in that The actuation assembly (52) includes an extendable arm (47) attached about a first end to a support plane (23) and about an opposite second end to a lever (49), the extendable arm (47) being attached to the support plane (23) and to the lever (49) being associated with the second pivoting means (28) for moving at least the access panel (27).

10. The device according to claim 3, characterized in that The delivery device (17) includes a fixed support structure (32) configured to slidingly accommodate a movable storage and delivery structure (33), the fixed support structure (32) being pivotally connected to a movable base (21) to adjust the inclination of the delivery device (17) in a vertical plane.

11. The device according to claim 2, characterized in that The slag crushing device (55) is associated with the delivery unit (16) and is provided with a slag crushing punch (56) configured to be lowered through the passage (53) of the cover plate (13) in order to crush a slag layer that may form on the inner surface of the latter.

12. Method for producing metal in a melting furnace (11), comprising at least one step of filling a tapping channel (15) of said melting furnace (11), characterized in that A delivery device (17) for delivering inert material (S) is supported by a support device (19) outside the furnace (11) and is rotatably movable, at least from a standby or parking state to an operational state, wherein in the standby or parking state, the delivery device (17) is arranged outside the body of the furnace (11), and in the operational state, the delivery device (17) is at least partially above the cover plate (13) of the furnace (11) so as to cooperate with the steel tapping channel (15), the delivery device (17) being associated with the cover plate (13) via a window unit (18), and selective access to the interior of the furnace (11) is allowed through the window unit (18) associated with the cover plate (13), When the delivery device (17) is in the operating state, the movable storage and delivery structure (33) of the delivery device (17) is translated towards the access panel (27) of the window unit (18), wherein the method provides that the access panel (27) is moved so as to make the central hole (26) of the access panel (27) available, allowing the inert material (S) to be discharged from the central hole (26) towards the steel tapping channel (15).

13. The method according to claim 12, characterized in that Before the central hole (26) is made available, the access panel (27) is rotationally moved in an alternating manner toward the interior of the furnace (11) and the exterior of the furnace (11) in order to break up a layer of slag and metal that may have formed on the inner surface (27a) of the access panel (27).

14. The method according to claim 12 or 13, characterized in that When it is necessary to fill the tank (36) of the delivery device (17), the delivery device (17) is rotationally moved to a loading state, which is different from the operating state.

15. The method according to claim 12, characterized in that Before discharging the inert material (S) toward the steel tapping channel (15) and after opening the window unit (18), the slag crushing equipment (30) crushes the layer of slag and metal present on the upper inner wall of the furnace (11), and the slag crushing equipment (30) includes a slag crushing device (55), and the slag crushing device (55) is provided with a slag crushing punch (56), and the slag crushing device (55) is driven by bringing the slag crushing punch (56) to a position perpendicular to the center hole (26) and aligned with the center axis of the center hole (26), and the slag crushing punch (56) is inserted through the center hole (26) to crush the existing slag layer.

16. The method according to claim 15, characterized in that After breaking up the slag layer, the slag breaking punch (56) is retracted to a parked position outside the furnace (11) and the delivery device (17) is repositioned to an operational state for discharging the inert material (S).

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