ELECTRIC ARC FURNACE WITH ELECTRODE CONTROL SYSTEM AND METHOD OF MANAGING ELECTRODES IN AN ELECTRIC ARC FURNACE

Description

DESCRIPTION Scope of application 5

[0001] The subject of this invention is an oven electric arc with regulation system electrodes and electrode management method in a electric arc furnace.

[0002] The electric arc furnace can be a furnace 10 vertical preheating of the shaft furnace type, or a batch-loading furnace or a batch-loading furnace continues. State of the art

[0003] Usually the direct fusion of materials 15 metals, especially those containing iron, such as example scrap, DRI or HBI, is performed in furnaces electric arc (Electric Arc Furnace, EAF).

[0004] In general, an operating cycle of a furnace electric arc includes five operational phases 20 main:

[0005] – loading the material to be melted into the furnace;

[0006] - melting of the loaded material, when using the electrodes and the injector-burners to melt the material itself; 25

[0007] – refining of the molten metal, when use oxygen injectors for decarburization;

[0008] - slagging of the molten metal bath; and

[0009] – tapping of molten metal.

[0010] In the same operating cycle of an oven 5 loading and melting phases can be repeated several times depending on the size of the oven vat. In fact, in many cases to create a bath of molten metal that uses the capacity of the vat, it may be necessary to refill the same vat several times 10 of the material to be melted; each loading must be then followed by a fusion phase.

[0011] In more detail, in batch furnaces the loading of the material takes place through baskets through the vault open, while in shaft furnaces the loading takes place 15 via one or more integrated shafts (vertical wells) in the vault. In both cases the loading of the material is always transported discontinuously. Differently, in continuous loading furnaces, made exception for the initial loading of the vat carried out 20 via open-vaulted baskets (or in cases of charging system malfunction / maintenance continues) the material to be melted is loaded through a continuous lateral opening while maintaining the electrodes inside the vat. 25

[0012] During the phase in which the oven is not dispensing electricity (power off), after tapping and before loading new material into the furnace melt, the electrodes are typically extracted from the oven to avoid being damaged by the material 5 which is loaded. Subsequently, finished the loading the material to be melted into the furnace, i.e. before the fusion phase, the insertion is planned checked the electrodes in the oven, completed the which will follow the ignition of the arc. 10

[0013] This situation occurs regularly (once or several times) at each operating cycle in the ovens batch and shaft furnaces. In charge furnaces continues, however, this situation occurs only at moment of the first charge (carried out via baskets 15 with the opening of the vault) or in the case of charging system malfunctions / maintenance continues that force loading via baskets.

[0014] After the material to be melted has been loaded in the oven, the electrodes must be inserted into the 20 oven, lowering them until they are close enough to the pile of material to be melted so that it can strike the arc. In the case of a batch furnace (and also in the (in the case of a continuous charging furnace) the movement of the electrodes is accompanied by that of the vault that 25 rotating together with the electrodes closes the oven; in case of shaft oven, the vault remains positioned above the vat and only the heights are moved electrodes to bring them back into the oven.

[0015] Currently, with reference to figure 4, which 5 schematizes a batch oven, in the reinsertion phase of the electrodes in the oven, each electrode is lowered from point 1 to point 3 with the same low speed so that there is no risk of collision of the electrode with the pile of material and the 10 resulting breakage of the tip. This leads to a waste of time between points 1 and 2 where you could proceed at a higher speed.

[0016] In the technical sector of reference there is therefore the still completely unsatisfied need to make 15 faster insertion phase of the electrodes in the oven without the risk of collisions between electrodes and pile of material to be melted.

[0017] As is known, fusion after fusion the electrode consumes. During the melting, the lower part 20 of the electrode is entirely enclosed inside the oven, resulting not visible from the outside. The only way that operators have to evaluate macroscopically the progress of the merger, is to observe the movement of the electrode holder arm. 25

[0018] This is especially true during the phase initial phase of the fusion, called "perforation", in which inside the oven there is a pile of material to be melted as soon as it is charged and the electrode penetrates into the pile, creating a hole. As already highlighted, this is 5 checks at each operating cycle in batch ovens after each unloading of a basket and in shaft ovens after each discharge of a shaft, while in charge furnaces continues occurs only in those situations where the oven is loaded via basket and not via 10 continuous charge.

[0019] At this stage, to get an estimate of the progress of the drilling, the descent of the clamp is observed electrode holder 31. The electrode holder clamp is part of of an electrode handling system. How 15 illustrated for example in figure 2, this system includes a support base 33 which can be rotating and from which a column extends in height of support 35 (generally equipped with a system hydraulic lifting). In turn the column 20 holds an arm 34 to the end of which is fixed the vice 31.

[0020] The descent of the electrode-holder arm, however always being comparable in subsequent castings for as regards the “magnitude” (intended as 25 difference between initial height and final height), is phased downwards, from fusion to fusion, of the length by which the electrode has shortened. If there is a measure of the height of the column, the diagram resulting (column position as a function of the number of 5 fusion / basket) can therefore be represented as a sawtooth decreasing at trend level (curve of the graph shown in figure 5; each peak and next valley corresponds to a descent of the electrodes and their permanence in the vat). This makes 10 It is difficult to make estimates through observation of the progress of the drilling phase. For example, in the first fusion represented in the graph of figure 5 there is was a more significant lowering of the column than to normal, but this is not recognizable with 15 immediacy.

[0021] In light of this, based on the observation of the movements of the electrode holder clamp (height column) an operator cannot understand if the perforation is proceeding physiologically or 20 no, and in general how the merger is progressing.

[0022] In the technical sector of reference there is therefore even the still completely unsatisfied need for monitor the progress of the drilling process to know whether or not it is happening physiologically 25 and implement countermeasures in subsequent mergers, for example by adopting stratification practices controlled by the basket or having control over how much It has been uploaded.

[0023] During the final phase of the operating cycle, 5 said refining phase, it is possible that inside the oven is equipped with:

[0024] - pieces of scrap (more massive) that are not were completely melted during the initial stages of the melting and which are in a bath; and / or 10

[0025] - accumulations in the wall (due to incorrect practice of layering of baskets, incorrect use of the auxiliary chemical energy on the perimeter of the vat or incorrect management of the arc length in the phase of fusion). 15

[0026] As the pieces move in the near the arch or even collapse from the wall towards the center (a fact that happens physiologically in the case of lateral continuous charge), the system of electrode adjustment would cause sudden lifting 20 the electrodes themselves, to prevent the material from impacts damaging them. Such sudden liftings, if repeated within a short period of time, can cause excessively the electrodes, as well as compromising (limiting) the power transfer to the bath 25 liquid.

[0027] In the technical sector of reference there is therefore even the still completely unsatisfied need for correlate the automatic interventions of the system electrode regulation to phenomena that occur 5 inside the oven so you can put it into action corrective actions in subsequent mergers.

[0028] In the refining phase of the melting furnace direct EAF, during decarburization FeO is generated and CO, which leaves the melt in the form of bubbles. The FeO must 10 then be reduced; to maintain a good yield and then to reduce FeO you inject carbon into the slag liquid that is found at the interface with the metal melted. In turn, the reduction of FeO generates further CO in the form of bubbles, increasing the level of 15 foaming slag.

[0029] The advantage of foamy slag formation is to create a volume capable of protecting the walls of the EAF shielding them from the electric arc. In This way the amount of energy released to the 20 molten metal, reducing electricity consumption and possible damage to the walls.

[0030] Operationally, during the refining phase (refining), the arc is, however, struck between the electrode and liquid bath without knowing exactly where it is 25 you find the level of the foamy waste. In case of where the bow was shot above the level of the slag, would not enjoy the shielding effect from part of the waste itself. This would result in an increase of energy losses through radiation towards the 5 cooled panels of the oven and vault. This It would increase electricity consumption and Tap-To-Tap time.

[0031] As a further consequence, there would also be a reduction in the life of the panels due to the large thermal load. 10

[0032] Similar problems are encountered in furnaces electric arc refining, e.g. furnace LF ladle in the case of ferrous materials. There are smelting processes in which the electric arc furnace is used in processing non-ferrous materials. Two 15 examples are the refining of copper scrap and the brass production. Electric arc furnaces are also used in the refining of precious materials (recycling of electronic waste or primary production of precious materials). 20

[0033] In the technical sector of reference there is therefore the still completely unsatisfied need for check the ignition of the electric arc according to the slag level so as to make the phase of more effective and efficient refinement than 25 what is currently being done. Presentation of the invention

[0034] Therefore, the main purpose of this invention is to eliminate in whole or in part the drawbacks of the above-mentioned prior art, 5 by providing an electric arc furnace with electrode regulation system that makes more efficient management of electrodes possible in one or more operating phases of an arc furnace electric. 10

[0035] A particular object of the present invention is that of making an arc furnace available electric with electrode adjustment system which allows the process to be carried out more quickly Inserting the electrodes into the oven without the risk 15 of collisions between electrodes and pile of material from to melt.

[0036] A particular object of the present invention is that of making an arc furnace available electric with electrode adjustment system 20 which allows you to monitor the progress of the process drilling so that the operator can see if is proceeding in the usual way or, on the contrary, if it is is checking for an anomaly. A particular object of the present invention is 25 that of making an arc furnace available electric with electrode adjustment system which allows to correlate the automatic interventions of the electrode regulation system with phenomena that check inside the oven so you can put 5 corrective actions underway in mergers subsequent. A particular object of the present invention is that of making an arc furnace available electric with electrode adjustment system 10 which allows to control the ignition of the arc electric based on the level of slag so as to make the refining phase more effective and efficient compared to what is currently done.

[0037] A further object of the present invention is 15 that of making an arc furnace available electric with electrode adjustment system that is operationally reliable and easy to manage.

[0038] A further object of the present invention is 20 that of making available a management method of electrodes that make it possible to manage more efficient electrodes in one or more phases of operation of an electric arc furnace. Brief description of the drawings 25

[0039] The technical characteristics of the invention, according to the above purposes, they are clearly verifiable from the content of the claims below reported and the advantages of the same will be evident more evident in the detailed description that 5 follows, made with reference to the attached drawings, which they represent one or more forms of embodiment purely exemplary and not limiting, in which:

[0040] - Figures 1, 2 and 3 show respectively a schematic view of a shaft type furnace, a furnace 10 batch (discontinuous) loading and one charging furnace continues;

[0041] – Figure 4 shows a schematic section of a batch oven after the loading phase before of the insertion of the electrodes; 15

[0042] – Figure 5 shows a graph of the trend of the height of the column of a system of electrode handling of an electric arc furnace depending on the number of fusion / basket during a multiple loading and fusion stages; 20

[0043] – Figure 6 shows a schematic view of a electric arc furnace 1 according to a form preferred embodiment of the invention;

[0044] – Figure 7 shows a schematic view of a electric arc furnace 1 according to a form 25 alternative embodiment of the invention;

[0045] – Figure 8 shows a graph of the trend temporal height of a column system electrode handling of an electric arc furnace with reference to the oven diagram in figure 4, 5 referring to a management method in agreement to the invention (graph a)) and in accordance with a known type modality (graph b)) during a phase of electrode insertion;

[0046] – Figure 9 shows a graph of the trend 10 of the electrode tip position as a function of time for the succession of mergers / baskets that can be processed by a electric arc furnace according to the invention during one or more loading and fusion phases;

[0047] – Figure 10 shows the superposition of the 15 graphs of figures 5 and 9;

[0048] – Figure 11 shows the trend graph of the position of the electrode tip in function of the time for the succession of mergers / baskets during one or more loading and fusion phases; 20

[0049] – figure 12 shows the graph relating to a reference time profile for the position of the electrode tip as a function of time for the succession of mergers / baskets during one or more phases of loading and melting, processed by an arc furnace 25 electric 1 according to the invention;

[0050] – Figures 13 to 15 show three examples of deviation from the reference time profile of the figure 12 from the tip position of the electrode as a function of time for the succession 5 of castings / baskets in an electric arc furnace during one or more loading and melting stages; and

[0051] – Figure 16 shows an example of the trend temporal position of the electrode tip in an electric arc furnace during a firing phase 10 refinement. Detailed description

[0052] The electric arc furnace with system adjusting the electrode level according to the invention was indicated overall with 1 15 in the attached Figures.

[0053] The electric arc furnace 1 according to the invention can be:

[0054] - a shaft-type vertical preheating furnace furnace, as illustrated for example in figure 1; 20

[0055] - a batch (discontinuous) charging furnace, such as illustrated for example in figure 2; or

[0056] - a continuous charging furnace, as illustrated in figure 3.

[0057] These types of ovens are in themselves well known to 25 an expert technician in the sector and therefore they will not be described in detail.

[0058] In accordance with a general embodiment of the invention, regardless of the specific typology, the electric arc furnace 1 includes a 5 vat 10 which is intended to be loaded with metallic material to generate a metal bath M-cast, on which a layer of slag forms in use S floating, which extends in height from the surface of the said bathroom up to a higher level 10 H variable over time. The 10 tank is equipped with a channel of tapping 11 and of a slagging door 12.

[0059] The electric arc furnace 1 further comprises, once 20 closing of the vat on which they are obtain one or more openings 21 for the insertion of a 15 or more electrodes.

[0060] The electric arc furnace 1 further comprises:

[0061] - one or more electrodes 22 insertable inside of the vat 10 through said one or more openings obtained in the vault; and 20

[0062] - an electrode handling apparatus 30.

[0063] The electrode handling apparatus 30 includes in turn:

[0064] - an electrode holder 31 suitable for supporting in vertical said one or more electrodes; and 25

[0065] – a support structure 32 of the vice holder- electrodes 31.

[0066] In more detail, as illustrated in figure 6, the support structure 32 of the electrode holder clamp 31 comprises a support base 33 from which it 5 extends a support column 35 in height. The latter in turn supports an arm 34 which supports vice 31.

[0067] The electric arc furnace 1 according to the invention It also includes a first detection apparatus 40 10 capable of detecting the position in real time vertical of said electrode holder clamp 31 with respect to a predefined reference point.

[0068] Preferably, said reference point is selected in a portion of the support base 33 15 of the electrode handling apparatus 30.

[0069] Advantageously, the first detection apparatus 40 can be of any type as long as it is capable of detecting in real time the vertical position of the said clamp electrode holder 31 with respect to a predefined point 20 reference.

[0070] Preferably, as illustrated in Figure 6, the first detection apparatus 40 consists of a linear position transducer associated with the column 35 of the support structure 32 of the vice holder 25 electrodes 31. Alternatively, the first apparatus of detection 40 can consist of any device for detecting the vertical position of the electrode holder clamp and / or of the column, for example, optical or radar or laser. 5

[0071] The electric arc furnace 1 according to the invention It also includes an image acquisition system 60 capable of acquiring images of said one or more electrodes when they are extracted from vat 10 and are positioned with respect to the 20th vault so that 10 the tip can also be framed and possibly also the wear area.

[0072] The term “electrode images” refers to is intended to refer generically to "representations of the electrode” which can be directly of the type 15 optical or can be reconstructions obtained from thermal signals (in the case of thermal imaging cameras) or from signals laser or radar.

[0073] By “tip of an electrode” is meant restrictively the lower end of the electrode 20 itself (i.e. the lowest point), while with “area "wear and tear" means more broadly a portion of end that is affected at each fusion wear and tear phenomena and that starting from the tip It progressively extends upwards during use. 25

[0074] In particular, as illustrated schematically in figures 6 and 7, the above mentioned apparatus image acquisition 60 may include one or more image acquisition devices 61, 62 arranged outside the vat. 5

[0075] Preferably said devices 61, 62 are cameras and / or thermal imaging cameras and / or 3D laser scanners or radar.

[0076] Operationally, as will be discussed below of the description, the image acquisition apparatus 10 60 is intended to acquire images of said one or more electrodes through said one or more devices 61, 62 which are preferably installed in a fixed position and remote from vat 10 and vault 20 for the purpose to obtain certain information about the electrodes. 15

[0077] Image acquisition is done after the electrode(s) were removed from vat 10 and are were positioned with respect to the vault 20 so that the tip and the area of ​​can also be framed wear and tear. 20

[0078] More in detail, in case oven 1 is a shaft-type furnace (in which the vault is generally it is not moved with respect to the vat as it is integrated with the loading structures (shafts) of the material to be melt), the electrodes are completely extracted from the 25 vat and positioned with the relative tips above from the upper edge of the vault.

[0079] In case oven 1 is a charge oven discontinuous (batch type) (in which the vault must be rotated with respect to the vat to allow 5 at the beginning of each fusion phase to load the material to be melted through baskets), the electrodes are completely extracted from the vat together with the vault and then rotated laterally; the relative position between time and electrodes can be varied so as to 10 make the electrode tips visible and possibly also the related wear areas, both in rotated position with respect to the vat is in position vertical above the vat (as in the case of the charge continues). 15

[0080] In case oven 1 is a single-load oven continues (in which the vault is generally not moved with respect to the vat as the regime material to be melted is loaded laterally and not from the vault), the normal operation of the oven requires 20 that the electrodes can be completely removed from the vat and positioned with the relative tips outside above the upper edge of the vault generally only on the occasion of the first charge and / or in case of malfunctions of the continuous charging system. 25

[0081] Advantageously, especially in the case of an oven with continuous charging, it is however possible to foresee extraction of the electrodes with closed vault frequency not strictly linked to the operation of the oven, even just to allow the acquisition of 5 images of the electrodes and in particular of their tips and possibly also wear areas.

[0082] Advantageously, the (low) speed of the electrode holder column also allows for the possibility of acquire images without having to stop the column 10 of the electrode handling system.

[0083] Operationally, it is preferable that the single image acquisition device can view, simultaneously in the same framing, the tip of the electrode and the grip of the 15 electrode holder arm. Alternatively, if this does not if it were possible, there could be two distinct and fixed imaging devices (e.g., one frames the tip and possibly the wear area of the electrodes and the other frames the clamp). In 20 alternative, if there is a single image acquisition device (but not capable to frame the tip and the vice in the same shot), it is possible that it uses a zoom operation; subsequently the image processing software 25 deals with reconstructing the distance from the tip to the clamped at a certain distance (from the devices) fixed.

[0084] In this way, the electrode being integral with the vice, the vice itself can be taken as 5 reference (for example to calculate the clamp distance – electrode tip) during a subsequent image processing.

[0085] Preferably, the information that can be obtained from the acquired images, by means of 10 a subsequent processing of the image, can be, for example, the following:

[0086] - electrode shape (reconstruct the perimeter of the electrode from the image)

[0087] - electrode length; 15

[0088] - width (radial) of the electrode;

[0089] - end portion conditions of the electrode (i.e. presence of crack phenomena or breakages)

[0090] It is known from practice that the consumption of the electrode 20 does not occur in a “one-dimensional” way (as in the case of the electrodes used in welding), but according to a “pencil point” shape. For this reason, it is advantageous that (through image processing) the shape of the electrode is reconstructed, understood as 25 a succession of points (Xi,Yi).

[0091] The electric arc furnace 1 further comprises an electric arc furnace control unit 70 comprising in turn a regulation system of the 700 electrodes which is used to regulate the ignition 5 and the positioning of the electrodes inside the vat and is operationally connected to the said apparatus electrode handling 30.

[0092] In particular, the regulation system electrodes 700 of the furnace 1 according to the invention is of 10 known type and will not be described in detail as known to a technician in the sector; for simplicity of description in the following we will describe the features that are added according to the invention.

[0093] According to the invention, said control unit of the 15 electric arc furnace 70 is operationally connected to said first detection apparatus 40 to acquire in real-time vertical position of said clamp electrode holder with respect to the said predefined point of reference. 20

[0094] According to the invention, said control unit of the electric arc furnace 70 is operationally connected also to said image acquisition apparatus 60 for acquire images of said electrodes and is configured to process said images in such a way that at each 25 extractions and for each electrode:

[0095] - identify the vertical position of the point lower than the electrode tip (Emin)

[0096] - identify the vertical position of the electrode holder clamp (F) 5

[0097] - calculate the length of the electrode (L = Emin - F)

[0098] - store data on the tip position of the electrode with respect to the electrode holder clamp, that is, the length of the electrode L. 10

[0099] The control unit of the electric arc furnace 70 is configured to calculate the position in vertical YE assumed over time by the tip of the electrode with respect to said reference point default, note the vertical position of that 15 electrode holder clamp acquired from said first apparatus of detection 40 and the length of the electrode L: YE = YF – L.

[00100] In other words, according to the invention, the electric arc furnace control unit 70 is 20 capable of reconstructing the position in real time of the tip of the electrodes based on:

[00101] - real-time acquired position of the vice;

[00102] – electrode tip distance – calculated clamp 25 at each electrode extraction.

[00103] Advantageously, said control unit 70 is programmed to activate the said apparatus image acquisition 60 when the electrodes are extracted from vat 10 and are positioned with respect to the 5 times 20 so that the ones can also be framed tip and possibly also the wear area.

[00104] The arc furnace control unit 70 electric is configured to regulate, via said 700 electrode adjustment system: 10

[00105] - the movements of the electrodes with respect to the vat 10 in terms of vertical position and / or speed; and / or

[00106] - the ignition time of the electric arc,

[00107] according to predefined programs 15 electrode management in different phases of operation of the electric arc furnace on the basis of the vertical position assumed by the tip of the electrode.

[00108] Advantageously, the control unit 70 of the 20 electric arc furnace is configured to adjust, via the said electrode regulation system 700, also the power of the electric arc.

[00109] Preferably, as will be resumed in the Next, the control unit 70 is configured to 25 adjust the movements of the electrodes and / or the time of ignition of the electric arc in the following phases of oven operation 1:

[00110] – inserting the electrodes into the oven after its loading; and 5

[00111] – optionally, bath refining molten metal.

[00112] In addition to or as an alternative to the fact that the control unit 70 is configured to adjust the electrode movements and / or ignition time 10 of the electric arc, the furnace control unit 70 electric arc is configured to generate a signal alarm in case during one or more phases of the oven operating cycle the progress of the vertical position assumed by the tip 15 of the electrode follows a temporal profile that deviates at least in part from a temporal profile of reference within predefined tolerances.

[00113] Thanks to the invention, the arc furnace electric with electrode adjustment system 20 enables more efficient management of electrodes in one or more phases of operation of a electric arc furnace, since it is possible implement electrode control modes knowing the position of the tips in real time 25 of the electrodes themselves also inside the vat.

[00114] In accordance with an embodiment preferred invention, the regulation system of the 700 electrodes can be configured to adjust the insertion of the electrodes into the vat - after a phase 5 loading the material to be melted - imposing to the electrodes:

[00115] - a first insertion speed up to when the tip of the electrodes is outside the vat and / or at a time; and 10

[00116] - a second speed, lower than the first, when the tip of the electrodes is inside the vat and / or at a time.

[00117] The second speed is chosen so that minimize the risk of electrode fracture 15 upon impact with the material to be melted. At the same time, the possibility of inserting the electrodes at a higher speed outside the vat and / or vault (i.e. in a safety zone) allows you to carry out the phase of 20 Inserting the electrodes into the oven without the risk of collisions between electrodes and pile of material to be to melt.

[00118] The above operational configuration of the 700 electrode adjustment system is functional 25 – as already mentioned – during the phase in which the oven does not is supplying electricity (power off), after the tapping and before loading into the oven again material to be melted. In this operating situation of the oven, the electrodes are typically extracted from the 5 furnace (especially from the vat in batch furnaces; and also from the vault in shaft furnaces) to avoid being damaged by the material being loaded. Afterwards, once the material has been uploaded, to be melted in the furnace, i.e. before the melting phase, 10 the controlled insertion of the electrode into the oven, once completed the ignition will follow of the bow. This situation occurs regularly at each operating cycle in batch ovens and furnaces shaft type. In continuous loading furnaces this type 15 situation occurs only at the time of the first loading (carried out via baskets with the opening of the time) or in case of malfunctions / maintenance of the continuous charging system which forces the loading via baskets. 20

[00119] After the material to be melted has been loaded into the oven, the electrodes must be inserted into the oven, lowering them until they are close to sufficiency of the amount of material to be melted in a way that the bow may be shot. 25

[00120] In the case of batch oven (and also in the case of continuous charging furnace) the movement of the electrodes is accompanied by that of the vault which rotates together the electrodes close the oven; in the case of oven shaft, the vault remains positioned above the vat of the 5 oven and only the heights are moved electrodes to bring them back into the oven.

[00121] Thanks to the invention, that is, thanks to the fact to know the position of the tips in real time of the electrodes, in the insertion phase it is possible 10 differentiate the speed of descent of the electrodes in depending on the position they are in progressively taking on respect to the vat and / or the time.

[00122] Figure 8 shows two 15 different speed profiles in the insertion of the electrodes: a first profile according to the invention (profile a) and a second profile according to a traditional mode (profile b). It is noted how adopting profile a) the ignition of the electric arc 20 be brought forward in time by a period of time indicated by ΔT. The time saved in a day it can also be estimated at 10-15 minutes.

[00123] In accordance with an embodiment alternative of the invention, the regulation system 25 of the 700 electrodes can be configured to adjust the insertion of the electrodes into the vat - after a phase loading of the material to be melted - imposing to the electrodes:

[00124] - a first insertion speed up to 5 when the tip of the electrodes reaches a distance of predefined safety from the accumulation of material, even inside the vat and / or vault; and

[00125] - a second speed, lower than the first, when the distance between the tip of the electrodes and the pile is 10 less than the said safety distance.

[00126] Advantageously, said system of electrode adjustment 700 is programmed for command the ignition of the electric arc after the the tip of the electrodes has reached the vicinity of the 15 material to be melted. In particular, this can be obtained thanks to a control on the electrical parameters of the electrode according to methods which are well known to a technician in the sector and for this reason not will be described here. 20

[00127] Preferably, the electric arc furnace 1 according to the invention further comprises a second detection apparatus 50 capable of detecting the upper level of slag.

[00128] Advantageously, the second apparatus of 25 detection 50 can be of any type as long as it is suitable to detect the upper level of slag over time. In particular, it can be a radar device or ultrasound.

[00129] Operationally, the upper level of 5 slag is detected as the distance between the second detection apparatus 50 (preferably associated to the vat) and the surface of the slag. Taking into account the fact that during the refining phase vat 10 is maintained typically horizontal, note the height position 10 of the second detection apparatus 50 is possible express the upper level of slag H in relation at the default reference point O.

[00130] Advantageously, said control unit of the electric arc furnace 70 can be 15 also operationally connected to the said second apparatus of detection 50 to acquire in real time the upper level of slag.

[00131] In accordance with an embodiment preferred invention, the regulation system 20 of the 700 electrodes can be programmed to adjust the movement of the electrodes inside the vat – during a refining phase of the metal bath - by forcing the electrodes to lower until the the tip of the electrodes has exceeded the level 25 top of the slag.

[00132] This is possible since according to the invention the control unit 70 is operationally connected to the second detection device 50 capable of detect the upper level of slag over time and can 5 then use the findings of that second apparatus 50. Furthermore, being indirectly detectable in real time (net of delays) introduced by the unit's data processing system (control) the position of the tip of the electrodes 10 also inside the vat, the control unit 70 – via the 700 electrode regulation system – is in able to regulate the movement of the electrodes compared to the upper level of slag.

[00133] Operationally, the electrode can be 15 lowered until the tip of the electrode appears to be found below the surface of the slag and, only then, the bow can be shot. In this way it turns out that the arc strikes under-slag and is limited radiation towards the side panels and the 20 times, increasing the transfer efficiency of energy to the bathroom.

[00134] Thanks to the invention, the arc furnace electric 1 with electrode adjustment system allows you to control the ignition of the electric arc 25 depending on the level of slag so as to make the phase more effective and efficient refining than what is currently being done.

[00135] Advantageously, said system of 700 electrode adjustment can be programmed 5 to control the ignition of the electric arc after the tip of the electrodes has exceeded the level top of the slag.

[00136] As already highlighted, according to the invention, the electric arc furnace control unit 70 is 10 configured to generate an alarm signal in case in which during one or more phases of the cycle operation of the oven the progress of the position in vertical assumed by the tip of the electrode follows a temporal profile that deviates at least in part from a 15 reference time profile within predefined tolerances.

[00137] Thanks to this the electric arc furnace 1 with electrode regulation system allows, in in particular, to monitor the progress of the process 20 drilling so that the operator can see if is proceeding in the usual way or, on the contrary, if it is is checking for an anomaly

[00138] Preferably, the oven 1 comprises a control panel connected to the control unit 25 70. The above alarm signal is displayed in called control panel.

[00139] A modality is described below preferred to define a descriptive time profile of the trend of the vertical position assumed 5 from the tip of an electrode during a phase of drilling / casting.

[00140] As is known, fusion after fusion the electrode it is consumed. During the smelting, the lower part of the electrode is entirely enclosed inside the oven, 10 resulting in it not being visible from the outside.

[00141] In the absence of information about the status of the electrodes inside the oven, it is possible macroscopically evaluate the progress of the fusion, observing the movement of the electrode holder clamp. 15

[00142] This is especially true during the phase initial phase of the fusion, called "perforation", in which inside the oven there is a pile of material to be melted as soon as it is charged and the electrode penetrates into the pile, creating a hole. 20

[00143] At this stage, to have an estimate of the drilling progress, you can observe the descent of the electrode holder clamp.

[00144] The descent of the electrode holder clamp, however always being comparable in subsequent mergers for 25 as regards the “magnitude” (intended as difference between initial height and final height), is phased downwards, from fusion to fusion, of the length by which the electrode has shortened.

[00145] Measuring the height of the door column 5 electrodes (or clamp) it is possible to trace a diagram that expresses the position of the column (or vice) depending on the number of castings / baskets and / or electrode extraction. This diagram can therefore be represented as a sawtooth profile that 10 decreases at the trend level, as illustrated in the curve of the graph shown in figure 5.

[00146] The decreasing sawtooth profile makes difficult to make estimates through observation of the drilling phase progress. 15

[00147] Thanks to the invention, however, it is possible know the position of the electrode tip (in particular fusion by fusion, therefore taking into account of the shortening that has occurred), so that we can compare in each fusion the trajectory that the tip 20 of the electrode actually does.

[00148] In more detail, in oven 1, before the loading of each basket (i.e. before each casting) whether it is a batch or shaft charge furnace continuous basket-fed) or at the end of each cycle 25 operating hours (if it is a continuous loading oven), and generally with each electrode extraction, it is possible measure the distance between the clamp (point integral with the electrode holder arm) and the electrode tip same. 5

[00149] Knowing how much the electrode is shortened, together with the height measurement of the electrode column, it is possible to produce a graph (electrode tip position as a function of time for the succession of baskets / mergers or in general 10 of electrode extractions) which is represented by a sawtooth profile as illustrated in the graph figure 9. This graph has a constant trend.

[00150] From the comparison of the two graphs (figure 5 and figure 9) visually represented in figure 10, is 15 note that the position of the electrode tip remains always within a certain range while the position of the column, despite having a constant width (position initial minus final position for each fusion / basket), it is gradually translated downwards. 20

[00151] Having the measurement of the position of the electrode tip, you can generate a graph by overlapping the saw teeth of successive castings. A An example of such a graph is shown in Figure 11.

[00152] Then, choosing a group of mergers 25 “representatives” for a given condition of loading and practice of the oven, for which the shape of the sawtooth is considered "physiological", it is it is possible to define a system fingerprint, such as illustrated in figure 12. This fingerprint 5 represents a reference time profile with relative predefined tolerances.

[00153] Advantageously, said control unit 70 It is programmed to generate an alarm signal different depending on predefined types of 10 deviation from the said time profile of reference.

[00154] A first type of deviation is defined in case the position of the electrode tip follows a temporal profile that differs from the 15 reference time profile with a stretch of invariance of position in height.

[00155] An example of such a situation is illustrated in the graph of figure 13, where the time profile analyzed is graph c) and the invariance trait 20 (horizontal) of the height position with respect to the reference time profile is indicated by h. This example is related to the presence of material partially conductive (or partially insulating) in the load. 25

[00156] More specifically, in case it is a piece of partially insulating material is present in charging, the arc current is lower (e.g. 30 kA) than what should be given (e.g. 60 kA) and consequently the fusion of that piece is more 5 long (see the horizontal section h of the curve c, which means the electrode is not going down). This causes increases in Power On Time (and consequence of Tap to Tap Time) since the arc has operated for a certain period of time to merge with 10 minor current.

[00157] The presence of partially conductive is due to a defect in operational practice and is substantially attributable to the lime and to how is provided in the process (can be caused by 15 malfunction of the crane or hopper or as was loaded into the basket) or, more rarely, of the presence of very low quality scrap.

[00158] Preferably, the curve c) (which comes out of the fingerprint in the manner illustrated above, that is, with a 20 horizontal section h in which the electrode remains still and then starts to go down again) can generate, following N mergers where this occurs, an alarm for the operator, warning him of the anomaly.

[00159] A second type of deviation is 25 defined in case the position of the tip of the electrode follows a temporal profile that deviates downwards from the time profile reference with a difference of less than one default threshold value. 5

[00160] An example of such a situation is illustrated in the graph of figure 14, where the time profile analyzed is graph d); the default value of threshold is represented by the dashed line tv, while the section of the graph in which the trend is 10 deviates downwards from the time profile reference is indicated with v1. This example is related to partial electrode breakage.

[00161] In case of breakage of a piece of the electrode that only affects a part of the 15 section of the electrode, you will see a more rapid descent fast electrode (not as much as the breakage of the entire section but still larger than the electrode in “physiological” conditions), as it will be like work with a smaller diameter electrode, which 20 so it is consumed first, bringing it after a short while anyway at the same deviation as in the case of a breakage of a electrode extended to the entire section.

[00162] A third type of deviation is defined in case the position of the electrode tip 25 follows a temporal profile that deviates towards the low compared to the reference time profile with a difference greater than the predefined value of theshold.

[00163] An example of such a situation is illustrated 5 in the graph of figure 15, where the time profile analyzed is the graph e); the default value of threshold is represented by the dashed line tv, while the section of the graph in which the trend is deviates downwards from the time profile 10 reference is indicated with v2. This example is related to the breakage of the entire section of the electrode.

[00164] In case of breakage of a piece of the electrode that affects the entire section 15 of the electrode, you will see a rapid descent of the tip position.

[00165] Advantageously, said control unit can be programmed to generate a signal of different alarm depending on predefined types 20 of deviation from a time profile of reference also relating to a refinement phase.

[00166] Preferably a type of deviation is defined in the case in which - during a phase of refining of the metal bath - the position of the 25 electrode tip follows a temporal profile that deviates upwards from the time profile of reference in the refinement phase by drawing one or more peaks.

[00167] Preferably, the time profile of 5 reference in the refining phase is defined by a electrode tip fluctuation band centered on an ideal average position that varies in function of the upper height of the slag.

[00168] An example of such a situation is illustrated 10 in the graph of figure 16, where the time profile analyzed is graph f) and the peaks are indicated with p1 and p2. This example is related to the presence inside the oven during the refining phase of the molten metal bath of: 15

[00169] - pieces of scrap (more massive) that are not were completely melted during the initial stages of the casting and which are found in the bath; and / or

[00170] - accumulations of material to be melted in the wall (due to incorrect practice of layering the baskets, 20 incorrect use of auxiliary chemical energy on perimeter of the vat or incorrect length management arc in the melting phase).

[00171] As the pieces move into the near the arch or even collapse from the wall 25 towards the center, the system automatically electrode adjustment causes it to lift suddenly the electrode with the risk of overstressing it and to prejudice (by limiting) the transfer of power to the liquid bath. 5

[00172] Operationally, if, in refining, one frequently witnesses the presence of massive pieces not melted or collapsed which require the electrode to be raised, the measure of the position of the tip of the electrode can give indications to the operator of 10 problems in loading phases (e.g. loading of massive pieces too large that cannot be fused in the drilling and casting phases) or of the need to change the fusion profile for allow for complete fusion to occur sooner 15 of refinement (e.g. increasing energy supplied by the burners or work, in the final part of the fusion phase, with a long arc, so as to radiate sufficiently towards the walls and be make sure to melt any pieces stuck to the 20 walls). The graph in figure 16 describes a situation which, in the case of basket-fed ovens or shaft type (or continuous-charge basket-fed) It is a symptom of a problem that occurred in the stages initials of the fusion, while in the case of furnaces 25 continuous charge is a physiological situation.

[00173] In accordance with an embodiment preferred, said control unit 70 is operationally connected to said image acquisition apparatus 60 to acquire images of said electrodes and is 5 configured to process said images in such a way that at each basket / fusion / extraction and for each electrode can:

[00174] - detect the electrode profile;

[00175] - compare captured image profiles 10 at different times, to determine the missing area due to electrode consumption and thus estimate the loss of volume and preferably, knowing the density, estimate even weight loss

[00176] - store weight loss data and 15 compare it with subsequent electrode consumption data.

[00177] Advantageously, said control unit 70 is configured to generate an alarm signal in the case in which the electrode consumption data differs from a reference time profile of consumption 20 electrode within predefined tolerances.

[00178] In accordance with an embodiment preferred, said control unit 70 is operationally connected to said image acquisition apparatus 60 to acquire images of said electrodes and is 25 configured to process said images in such a way that for each extraction / basket / fusion and for each electrode can store the image of the tip of the electrode and possibly of the wear area.

[00179] Advantageously, said control unit 70 5 includes a library of images of phenomena of electrode damage and is configured for compare the acquired images with the said library images to recognize any phenomena of damage so as to generate an alarm signal. 10

[00180] Advantageously, said control unit 70 is configured to generate an alarm signal in the case where the acquired images are comparable with one or more images from said image library.

[00181] It may happen that, in order to maximize the 15 production, a plant tries to continue producing without worrying about proceeding with the lengthening of the electrode (slipping) or even the addition of a segment, operations that are time consuming and slow down production. 20

[00182] When it happens that the electrode is so short that the electrode column has reached the end of its travel lower and can't go down any further, the electrode is unable to work as required from the electrode regulator, in particular it will work 25 providing lower power, resulting in increased of Power On Time.

[00183] Measuring the length of the fusion electrode after the merger, a consumption trend can be extracted, such that the operator can predict with good accuracy 5 when it will be necessary to proceed with the lengthening electrode or adding a snip.

[00184] This has a major impact as the EAF machine downtime (e.g. due to (electrode elongation) impact on production 10 downstream (e.g. at least LF and continuous casting) and the ability to schedule when these stops will happen gives the advantage of managing production in optimal way. * * * 15

[00185] The present invention also forms the subject of a method of managing the electrodes of a furnace electric arc 1 according to the invention and in particular as described above.

[00186] For simplicity of discussion, the method of 20 electrode management will be described with reference to the preceding part of the description in which the oven 1 according to the invention has already been described.

[00187] According to a general form of implementation of the invention, the management method 25 of the electrodes of an electric arc furnace 1 includes the following operational phases:

[00188] a) each time the electrodes are switched off extract said one or more electrodes from the vat 10 positioning them with respect to the vault 20 in such a way that 5 the tip and the possibly also the area of ​​wear by the said image acquisition apparatus 60;

[00189] b) acquire images of said one or more electrodes after phase a) through the said apparatus 10 image acquisition 60.

[00190] The electrodes can be switched off at the beginning, during and / or at the end of each cycle of operation of the electric arc furnace; in particular can occur at the end of each merger 15 (in the case of a continuous loading oven) or before loading (for batch or shaft type furnaces) continuous charge powered exceptionally by baskets) or depending on the detection needs of the state of electrodes in the continuous charging furnace. 20

[00191] The method of managing the electrodes includes the operational phase c) of developing said images via the control unit 70 in such a way that at each extraction electrodes and for each electrode: 25

[00192] - the vertical position is identified of the lowest point of the electrode tip (Emin)

[00193] - the vertical position is identified of the electrode holder clamp (F)

[00194] - let the length of the electrode be calculated 5 (L = Emin - F)

[00195] - the location data is stored of the electrode tip with respect to the clamp- electrode, or the length of the electrode L.

[00196] The method of managing the electrodes according to 10 the invention also includes the operational phases:

[00197] d) at the end of each shutdown of the electrodes (power off), reinsert said one or more electrodes inside said vat;

[00198] e) detect the position in real time 15 vertical of such YF electrode holder clamp via said first detection apparatus 40,

[00199] g) calculate the vertical position YE assumed over time by the tip of the electrode with respect to said default reference point, note the 20 vertical position of this YF electrode holder clamp and the length of the electrode L: YE = YF - L.

[00200] Preferably, said reference point is selected in a portion of the support base 33 of the electrode handling apparatus 30. 25

[00201] Phase b) of image acquisition is conducted between phase a) of electrode extraction and the phase d) of electrode reinsertion.

[00202] In particular, phase b) of acquiring images is conducted after the said phase a) in which the 5 electrodes were taken out from vat 10 and were positioned with respect to the 20th vault so that the tip can also be framed and possibly also the wear area.

[00203] Preferably, the processing phase c) 10 images is conducted before phase d) of reinsertion of electrodes.

[00204] Phase e) to detect in real time the vertical position YF of this electrode holder clamp is conducted at the same time as phase g) of 15 calculate the vertical position assumed over time from the tip of the electrode with respect to the said point of default reference, note the vertical position of this electrode holder clamp.

[00205] The two phases e) and g) allow to trace 20 a time profile for the performance of the position in vertical YE assumed by the tip of the electrode. In particular, the temporal profile refers to the trend of the tip position during the a single fusion. 25

[00206] The method of managing the electrodes according to the invention further comprises the operational step h) of regulate, through the said regulation system of the electrodes 700:

[00207] - the movements of the electrodes with respect to the 5 tino 10 in terms of vertical position and / or speed; and / or

[00208] - the arc ignition time,

[00209] according to predefined programs electrode management in different phases of 10 operation of the electric arc furnace on the basis of the vertical position assumed by the tip of the electrode as calculated in step g).

[00210] Preferably, said regulation phase h) is conducted during the following phases of operation 15 of oven 1:

[00211] – inserting the electrodes into the oven after its loading; and

[00212] – optionally, bath refining molten metal. 20

[00213] In addition to or as an alternative to phase h) of regulation, the method of managing the electrodes according to the invention comprises the operational phase i) of generate an alarm signal in case during one or more phases of the oven operating cycle 25 the trend of the vertical position assumed by the electrode tip follows a temporal profile that deviates at least in part from a temporal profile of reference within predefined tolerances.

[00214] According to one form of implementation 5 preferred embodiment of the invention, during said phase d) the insertion of said one or more electrodes inside of the said vat is regulated by imposing on the electrodes imposing on the electrodes:

[00215] - a first insertion speed up to 10 when the tip of the electrodes is outside the vat and / or at a time; and

[00216] - a second speed, lower than the first, when the tip of the electrodes is inside the vat and / or at a time. 15

[00217] The second speed is chosen so as to minimize the risk of electrode fracture upon impact with the material to be melted.

[00218] Advantageously, during said phase d) the insertion of said one or more electrodes inside 20 of said vat, through said regulation system of the electrodes 700, the ignition of the arc is controlled electric after the tip of the electrodes has reached in proximity to the material to be melted.

[00219] Advantageously, the method may comprise 25 a phase f) to detect the level in real time upper slag through said second apparatus detection 50 during a refinement phase of the bath of molten metal.

[00220] In this case, the regulation phase h) is 5 conducted, in a bath refinement phase metallic, also based on the higher level of slag.

[00221] According to one form of implementation preferred invention, during a phase of 10 refining of the metal bath the movement of the electrodes inside the vat is regulated by said 700 electrode regulation system imposing to the electrodes to lower until the tip of the electrodes themselves have exceeded the upper level 15 of the slag.

[00222] Advantageously, during the said phase of refining of the metal bath, through the said system of electrode regulation 700, is controlled the ignition of the electric arc after the tip of the 20 electrodes has passed the upper level of the slag.

[00223] Preferably, during each cycle of operation every deviation from a profile reference time in the fusion phase / 25 drilling, within predefined tolerances, by of the trend of the vertical position assumed from the tip of the electrode, it is classified according to predefined types of deviation, for each of the which are correlated with a different alarm signal. 5

[00224] Resuming what has already been described in relation in the oven 1, three possible types of are listed deviation.

[00225] A first type of deviation is defined in case the position of the electrode tip 10 follows a temporal profile that differs from the reference time profile with a stretch of invariance of position in height. An example of This situation is illustrated in the graph in figure 13.

[00226] A second type of deviation is 15 defined in case the position of the tip of the electrode follows a temporal profile that deviates downwards from the time profile reference with a difference of less than one default threshold value. An example of such 20 situation is illustrated in the graph in figure 14.

[00227] A third type of deviation is defined in case the position of the electrode tip follows a temporal profile that deviates towards the low compared to the reference time profile with 25 a difference greater than the said default value of threshold. An example of such a situation is illustrated in the graph in figure 15.

[00228] Advantageously, during each cycle of operation of the oven any deviation from a 5 reference time profile relating to a phase of refinement, within predefined tolerances, by of the trend of the vertical position assumed from the tip of the electrode, can be classified according to predefined types of deviation for each 10 of which are correlated with a different signal alarm.

[00229] Preferably a type of deviation is defined in the case in which - during the phase of refining of the metal bath - the position of the 15 electrode tip follows a temporal profile that deviates upwards from the time profile of reference by drawing one or more peaks. An example of This situation is illustrated in the graph in figure 16.

[00230] According to one form of implementation 20 preferred of the invention, through said unit of control 70 in said processing phase c) the images acquired in the said phase b) are processed in so that at each extraction electrodes (in particular to each basket / load, for batch ovens or 25 shafts or continuous loading fed by baskets, or at each operating cycle for continuous loading furnaces) and for each electrode:

[00231] - the electrode profile is detected;

[00232] - image profiles are compared 5 captured at different times, to determine the area missing due to electrode consumption and thus estimate the loss of volume and preferably, note the density, also estimate weight loss

[00233] - weight loss data is stored 10 and then compared with subsequent consumption data electrode.

[00234] Preferably, the method comprises the step l) to generate via said control unit 70 a alarm signal in case the consumption data 15 electrode deviates from a temporal profile of electrode consumption reference within predefined limits tolerances.

[00235] Preferably, via said unit of control 70 in said processing phase c) the 20 images acquired in the said phase b) are processed in so that after each extraction electrodes (in particular to each basket / load, for batch ovens or shaft or continuous loading fed by baskets, or at each operating cycle for continuous loading furnaces) and 25 for each electrode the image is also stored of the electrode tip and also the wear area.

[00236] Advantageously, the method may comprise phase m) of comparing via the said unit of control 70 images acquired with a library of 5 images of electrode damage phenomena for recognize any damage phenomena and so on generate an alarm signal.

[00237] Preferably, the method comprises a step n) to generate via said control unit 70 a 10 alarm signal in case the acquired images are comparable with one or more images of said image library.

[00238] The advantages deriving from the method according to the invention are the same as those already described in 15 relation to the oven 1 according to the invention and will not be presented again for simplicity of presentation.

[00239] The invention allows to obtain numerous advantages already partly described.

[00240] The electric arc furnace with system 20 adjustment of the electrodes according to the invention makes more efficient management of electrodes possible in one or more operating phases of an arc furnace electric.

[00241] The electric arc furnace with system 25 electrode adjustment according to the invention allows you to carry out the phase of Inserting the electrodes into the oven without the risk of collisions between electrodes and pile of material to be to melt. 5

[00242] The electric arc furnace with system electrode adjustment according to the invention allows you to monitor the progress of the process drilling so that the operator can see if he is proceeding in the usual way or, on the contrary, if you are 10 checking for an anomaly. The electric arc furnace with regulation system of the electrodes according to the invention allows to correlate the automatic interventions of the system electrode regulation to phenomena that occur 15 inside the oven so that you can put into action corrective actions in subsequent mergers. The electric arc furnace with regulation system of the electrodes according to the invention allows to check the ignition of the electric arc according to the 20 level of slag so as to make the phase of more effective and efficient refinement than what is currently being done.

[00243] The electric arc furnace with system regulation of the electrodes according to the invention is 25 operationally reliable and easy to manage.

[00244] The method of managing the electrodes according to the invention makes easier management possible efficient electrodes in one or more phases of operation of an electric arc furnace. 5

[00245] The invention thus conceived reaches therefore the intended purposes.

[00246] Obviously, it will be able to assume, in its practical realization of shapes and configurations different from the one illustrated above without, for 10 this, you go outside the scope of this protection.

[00247] Furthermore, all the details can be replaced by technically equivalent elements and the dimensions, shapes and materials used will be able to be whatever you need.

Claims

1. Electric arc furnace (1) comprising: 5 - a vat (10) which is intended to be loaded with metallic material to generate a metal bath molten (M), on which a layer of slag forms in use (S) floating, which extends in height from the surface of the said bathroom up to a higher level 10 (H) variable over time, said vat (10) being equipped of a tapping channel (11) and a door slagging (12); - once (20) of closing of the vat on which are obtain one or more openings (21) for the insertion of 15 one or more electrodes; - one or more electrodes (22) that can be inserted inside the vat (10) through said one or more openings; - an electrode handling apparatus (30), comprising an electrode holder clamp (31) suitable for 20 support said one or more electrodes vertically, - a first detection apparatus (40) capable of detecting in real time the vertical position of the said clamp electrode holder (31) with respect to a predefined point reference; - an image acquisition apparatus (60) suitable for acquire images of said one or more electrodes when are extracted from the vat (10) and are positioned with respect to at a time (20) so that they can be framed 5 also the tip and possibly also the wear area; - an electric arc furnace control unit (70) comprising in turn a system for regulating the electrodes (700) which is used to regulate the ignition and the positioning of the electrodes inside the vat and 10 is operationally connected to the said apparatus electrode handling (30) characterized by the fact that said control unit of the electric arc furnace (70) is operationally connected to said first detection apparatus (40) for 15 acquire the vertical position YF in real time) of said electrode holder clamp with respect to said default reference point; and from the fact that the said furnace control unit electric arc (70) is operationally connected to said 20 image acquisition apparatus (60) for acquiring images of said electrodes and is configured to process said images in such a way that at each electrode extraction and for each electrode: - identify the vertical position of the highest point 25 low electrode tip (Emin) - identify the vertical position of the vice electrode holder (F) - calculate the length of the electrode (L = Emin - F) - store the data on the tip position 5 of the electrode with respect to the electrode holder clamp, that is, the length of the electrode L, wherein said arc furnace control unit electric (70) is configured to calculate the position vertically (YE) assumed over time by the tip 10 of the electrode with respect to said reference point default, note the vertical position (YF) of that electrode holder clamp acquired from said first apparatus of detection (40) and the length of the electrode (L), and wherein said arc furnace control unit 15 electric (70) is configured to regulate, via said electrode regulation system (700): - the movements of the electrodes with respect to the vat (10) in terms of vertical position and / or velocity; and / or - the arc ignition time 20 according to predefined management programs electrodes in different phases of operation of the furnace electric arc based on the vertical position taken from the tip of the electrode, and / or is configured to generate an alarm signal in the 25 case in which during one or more phases of the cycle operation of the oven the progress of the position in vertical assumed by the tip of the electrode follows a temporal profile that deviates at least in part from a reference time profile within predefined timeframes 5 tolerances.

2. Electric arc furnace (1) according to the Claim 1, wherein said adjustment system of the electrodes (700) is configured to regulate the insertion of the electrodes into the vat - after a phase 10 loading of the material to be melted - imposing on the electrodes a first speed until the tip of the electrodes are external to the vat and a second speed, lower than the first, when the tip of the electrodes is inside the vat, in which said second speed is chosen 15 in order to minimize the risk of fracture of the electrodes upon impact with the material to be melted.

3. Electric arc furnace (1) according to the claim 2, wherein said adjustment system of the electrodes (700) is programmed to control 20 the ignition of the electric arc after the tip of the electrodes came in proximity of the material to be to melt.

4. Electric arc furnace (1) according to the Claim 1, 2 or 3, comprising a second apparatus 25 detection (50) capable of detecting the level over time upper slag, wherein said control unit electric arc furnace (70) is operationally connected to said second detection apparatus (50) for acquire the upper level of slag in real time 5 and wherein said arc furnace control unit electric (70) is configured to regulate, via said electrode regulation system (700): - the movements of the electrodes with respect to the vat (10) in terms of vertical position and / or velocity; and / or 10 - the arc ignition time according to predefined management programs electrodes in a phase of operation of the arc furnace electric relating to the refining of the metal bath spindle, based on the vertical position assumed 15 from the tip of the electrode and also on the base of the level upper slag, wherein preferably said regulation system of the electrodes (700) is programmed to regulate the movement of the electrodes inside the vat – 20 during the said refining phase of the metal bath - by forcing the electrodes to lower until the the tip of the electrodes has exceeded the level top of the slag.

5. Electric arc furnace (1) according to the 25 claim 4, wherein said adjustment system of the electrodes (700) is programmed to control the ignition of the electric arc after the tip of the electrodes have exceeded the upper level of the slag. 5 6. Electric arc furnace (1) according to a any of the preceding claims, including a control panel and where said alarm signal is displayed in the said control panel.

7. Electric arc furnace (1) according to a 10 any of the preceding claims, wherein said control unit is programmed to generate a signal of different alarm depending on predefined types of deviation from a time profile of reference to a fusion phase. 15 8. Electric arc furnace (1) according to the claim 7, wherein a first type of deviation is defined in the case where the position of the electrode tip follows a temporal profile that deviates from the reference time profile 20 in the fusion phase with a trait of invariance of the height position.

9. Electric arc furnace (1) according to the claim 7 or 8, wherein a second type of deviation is defined in the case where the position of the 25 electrode tip follows a temporal profile that deviates downwards from the time profile of reference in the fusion phase with a difference lower than a predefined threshold value.

10. Electric arc furnace (1) according to the 5 claim 7, 8 or 9, wherein a third type of deviation is defined in the case where the position of the electrode tip follows a temporal profile that deviates downwards from the time profile of reference in the fusion phase with a difference 10 higher than the default threshold value.

11. Electric arc furnace (1) according to a any of the preceding claims, where said control unit is programmed to generate a signal of different alarm depending on predefined types 15 deviation from a time profile of reference relating to a refinement phase and in where preferably a type of deviation is defined in the case where - during the refining phase of the metal bath - the position of the tip 20 of the electrode follows a temporal profile that deviates upwards from the time profile of reference in the fusion phase by drawing one or more peaks.

12. Electric arc furnace (1) according to a 25 any of the preceding claims, wherein said reference point is chosen in a portion of a base of the electrode movement apparatus (30).

13. Electric arc furnace (1) according to a any of the preceding claims, where said 5 control unit (70) is operationally connected to said image acquisition apparatus (60) for acquire images of said electrodes and is configured to process said images in such a way that after each electrode extraction and for each electrode you can: 10 - detect the electrode profile; - compare profiles of images captured in instants different, to determine the missing area due to the electrode consumption and thus estimate the loss of volume and preferably, knowing the density, also estimate the 15 weight loss - store weight loss data and compare it with subsequent electrode consumption data.

14. Electric arc furnace (1) according to the claim 13, wherein said control unit (70) 20 is configured to generate an alarm signal in case where the electrode consumption data deviates from a reference time profile of electrode consumption within predefined tolerances.

15. Electric arc furnace (1) according to a 25 any of the preceding claims, wherein said control unit (70) is operationally connected to said image acquisition apparatus (60) for acquire images of said electrodes and is configured to process said images in such a way that for each 5 extraction of electrodes and for each electrode it can store the image of the electrode tip and of the wear area and in which said control unit (70) includes a library of images of phenomena of electrode damage and is configured for 10 compare the acquired images with the said library images to recognize any phenomena of damage so as to generate an alarm signal.

16. Electric arc furnace (1) according to the claim 15, wherein said control unit (70) 15 is configured to generate an alarm signal in case where the acquired images are comparable with a or more images from that image library.

17. Electric arc furnace (1) according to a any of the preceding claims, where said 20 control unit (70) is programmed to activate said image acquisition apparatus (60) when the electrodes are extracted from the vat (10) and are positioned with respect to the vault (20) so that the results are the tip and possibly also the tip can also be framed 25 wear zone.

18. Electric arc furnace (1) according to a any of the preceding claims, wherein said image acquisition apparatus (60) comprises one or multiple imaging devices (61, 62) 5 placed outside the vat, preferably called devices (61, 62) being cameras and / or thermal imaging cameras and / or 3D laser scanner.

19. Method of managing the electrodes of a furnace electric arc (1) according to any of the 10 previous claims, comprising the following steps operational: a) each time the electrodes are switched off - at the beginning, during and / or at the end of each cycle of electric arc furnace operation (1) - extract 15 said one or more electrodes from the vat (10) by positioning them with respect to the vault (20) so that the results are the tip and possibly also the tip can also be framed wear area of ​​said acquisition device images (60); 20 b) acquire images of said one or more electrodes after phase a) via the said acquisition device images (60); c) process said images by said unit control (70) so that at each extraction 25 electrodes and for each electrode: - the vertical position of the point is identified lower than the electrode tip (Emin) - the vertical position of the clamp is identified electrode holder (F) 5 - calculate the length of the electrode (L = Emin - F) - the tip position data is stored of the electrode with respect to the electrode holder clamp, that is, the length of the electrode L, 10 d) at the end of each electrode shutdown reinsert said one or more electrodes inside said vat; e) detect the vertical position in real time (YF) of such electrode holder clamp via said first 15 detection apparatus (40), f) optionally detect in real time the upper level of slag (H) via said second detection apparatus (50) during a phase of refining of the molten metal bath, 20 g) calculate the vertical position (YE) assumed in time from the tip of the electrode to the said default reference point, note the position in vertical of this electrode holder clamp (YF) and the electrode length (L), 25 h) regulate, through the said regulation system of the electrodes (700): - the movements of the electrodes with respect to the vat (10) in terms of vertical position and / or velocity; and / or - the arc ignition time and / or power 5 of the bow according to predefined management programs electrodes in different phases of operation of the furnace electric arc based on the vertical position assumed by the tip of the electrode as calculated in 10 phase g) and optionally, in a refinement phase of the metal bath, also based on the upper level of slag, and / or i) generate an alarm signal in case 15 during one or more phases of the casting cycle operation of the oven the trend of the vertical position assumed by the tip of the electrode follows a profile storm that deviates at least in part from a profile reference time within predefined tolerances. 20 20. Method according to claim 19, wherein during the said phase d) the insertion of said one or more electrodes inside the said vat is regulated by imposing to the electrodes a first speed until the tip of the electrodes is external to the vat and a second 25 speed, lower than first, when the tip of the electrodes is inside the vat, in which said second speed is chosen so as to minimize the risk of fracture of the electrodes upon impact with the material to be melt previously loaded into the vat. 5 21. Method according to claim 20, wherein during the said phase d) the insertion of said one or more electrodes inside said vat, through said electrode regulation system (700), is commanded the ignition of the electric arc after the 10 tip of the electrodes came close to the material to be melted.

22. Method according to claim 19, 20 or 21, in which during a bath refining phase metallic the movement of the electrodes inside 15 of the vat is regulated by the said regulation system of the electrodes (700) by imposing on the electrodes lower until the tip of the electrodes themselves has exceeded the upper level of the slag.

23. Method according to claim 22, wherein 20 during the said refining phase of the metal bath, via the said electrode regulation system (700), the ignition of the electric arc is commanded after that the tip of the electrodes has exceeded the level top of the slag. 25 24. Method according to any of the claims 19 to 23, where during each cycle of oven operation any deviation from a reference time profile relating to a phase of fusion, within predefined tolerances, by 5 of the trend of the vertical position assumed from the tip of the electrode, it is classified according to predefined types of deviation to each of the which are correlated with a different alarm signal.

25. The method of claim 24, wherein a 10 first type of deviation is defined in the case in where the position of the electrode tip follows a temporal profile that deviates from the profile reference time frame in the fusion phase with a trait of invariance of the position in height. 15 26. Method according to claim 24 or 25, in in which a second type of deviation is defined in case where the position of the electrode tip follows a time profile that deviates downwards compared to the reference time profile in the phase 20 fusion with a difference less than a predefined one threshold value.

27. Method according to claim 24, 25 or 26, where a third type of deviation is defined in case where the position of the electrode tip follows 25 a time profile that deviates downwards compared to the reference time profile in the phase of fusion with a difference greater than said default threshold value.

28. Method according to any of the 5 previous claims, where during each cycle of oven operation any deviation from a reference time profile relating to a phase of refinement, within predefined tolerances, by of the trend of the vertical position assumed 10 from the tip of the electrode, is classified according to predefined types of deviation to each of the which is correlated with a different alarm signal and in where preferably a type of deviation is defined in the case where - during the refining phase 15 of the metal bath - the position of the tip of the electrode follows a temporal profile that deviates upwards from the time profile of reference by drawing one or more peaks.

29. Method according to any of the 20 claims 19 to 28, wherein said point of reference is chosen in a portion of the base of the electrode handling apparatus (30).

30. Method according to any of the claims 19 to 29, wherein by means of said unit of 25 control (70) in said processing phase c) the images acquired in the said phase b) are processed in so that after each extraction electrodes and for each electrode: - the electrode profile is detected; 5 - profiles of captured images are compared in different instants, to determine the missing area due to consume electrodes and thus estimate the volume loss and preferably, knowing the density, also estimate the weight loss 10 - the weight loss data is stored and then compared with subsequent electrode consumption data.

31. Method according to claim 30, comprising phase l) of generating via said unit control (70) an alarm signal in case 15 the electrode consumption data deviates from a profile electrode consumption reference time within predefined tolerances.

32. Method according to any of the claims 19 to 31, wherein by means of said unit of 20 control (70) in said processing phase c) the images acquired in the said phase b) are processed in so that after each extraction electrodes and for each electrode also stores the image of the electrode tip and wear zone and where 25 said method includes the step m) of comparing via said control unit (70) the images acquired with a library of images of damage phenomena electrodes to recognize any phenomena of damage and thus generate an alarm signal. 5 33. Method according to claim 32, comprising a phase n) of generating via said unit control (70) an alarm signal in case the acquired images are comparable with one or more images from the said image library. 10 34. Method according to any of the claims 19 to 33, wherein said step b) of acquiring images is conducted after the said phase a) in which the electrodes were removed from the vat (10) and are were positioned with respect to the vault (20) so that 15 the tip and the possibly also the wear area.