Rotating ladle molten metal processing device

Abstract

The present invention relates to a device for processing molten metal, said device comprising a ladle defining an internal volume for containing said molten metal. According to the invention, said device comprises means for rotating said ladle about at least one first axis of rotation. Fig. 1

Description

Title of the invention: Device for treating molten metal with a rotating ladle 1. Field of the invention

[0001] The field of the invention is that of the treatment of molten metal, in particular cast iron or any other alloy such as ferrous alloys, copper alloys, light alloys or others.

[0002] The invention relates more particularly to the devices implemented to ensure, at least partially, the treatment of such materials, more particularly the pockets implemented for this purpose. 2. Prior art

[0003] In the field of metallurgy, it is common to produce metal parts by casting. To do this, a furnace is used to melt a metal or a metal alloy. The molten metal then undergoes a plurality of successive treatments before being poured into a mold. These treatments include desulfurization, initialization (i.e. germination), nodularization, and inoculation.

[0004] Each of the treatments undergone by the molten metal between its exit from the furnace and its casting into a mold is carried out in a specific treatment ladle. Thus, according to the prior art, as many treatment ladles are used as the metal must undergo treatments. Thus, if the molten metal must, for example, undergo four treatments, i.e. desulfurization, initialization, nodularization and inoculation between its exit from the furnace and its casting into a mold, at least four treatment ladles will be used, each being dedicated to one of the treatments.

[0005] This leads to multiplying the number of pockets used and therefore to increasing the cost of the treatment tools as well as their size.

[0006] Furthermore, the various treatments require the injection of at least one reagent into the molten metal contained in the pockets. The pockets are static so that the reagent is supposed to mix with the molten metal by itself or during transfer. This may mean that the reagent is not perfectly mixed with the molten metal or that it is necessary to leave the reagent in contact with the molten metal for a long time to ensure sufficient mixing.

[0007] This tends to harm the productivity of treatments and / or their quality.

[0008] There is therefore a need to improve the techniques for treating molten metals, particularly cast irons. 3. Objectives of the invention

[0009] The invention aims in particular to provide an effective solution to at least some of these different problems.

[0010] In particular, according to at least one embodiment, an objective of the invention is to provide a technique for treating molten metal which makes it possible to improve the productivity of the treatment(s) carried out.

[0011] In particular, the invention aims, according to at least one embodiment, to provide such a technique which makes it possible to improve the mixing of a reactant with a molten metal.

[0012] Another objective of the invention is, according to at least one embodiment, to provide such a technique which contributes to increasing the treatment volume of the molten metal.

[0013] Another objective of the invention is, according to at least one embodiment, to provide such a technique which contributes to increasing the productivity of a furnace used to produce molten metal.

[0014] Another objective of the invention is, according to at least one embodiment, to provide such a technique which is versatile, in particular in that it allows the same equipment to be used to carry out different treatments.

[0015] Another objective of the invention is, according to at least one embodiment, to provide such a technique which contributes to reducing the cost of treating a molten metal.

[0016] Another objective of the invention is, according to at least one embodiment, to provide such a technique which is simple in design and / or reliable and / or inexpensive. 4. Presentation of the invention

[0017] For this, the invention proposes a device for treating a molten metal, said device comprising a pocket defining an interior volume intended to contain said molten metal.

[0018] According to the invention, such a device comprises means for driving said pocket in rotation along at least a first axis of rotation.

[0019] Thus, according to this aspect of the invention, on an original approach consisting of implementing a rotating treatment pocket.

[0020] This implementation makes it possible to ensure rapid and efficient mixing of the reagent(s) with the molten metal contained in the pocket, which contributes to:

[0021] - improve the quality of treatment;

[0022] - consequently increase the efficiency of the treatment in the pocket;

[0023] - accordingly increase the internal volume of the pocket;

[0024] - consequently increase the versatility of the pocket by making it possible to carry out successively different treatments, and

[0025] - the productivity of the furnace insofar as it can be emptied more often because the the pocket volume is larger and therefore also filled more often

[0026] According to a possible characteristic, said pocket comprises a peripheral internal wall having surface irregularities.

[0027] The presence of such surface irregularities makes it possible to improve mixing in the pocket.

[0028] According to a possible characteristic, said surface irregularities consist of the raw demolding appearance of said pocket.

[0029] When the pocket is made by molding the refractory material, its interior surface is not smooth but has asperities which improve cleaning in the pocket.

[0030] According to a possible characteristic, said irregularities are constituted by at least one element forming a projection in the direction of said interior volume.

[0031] This implementation makes it possible to improve the cleaning in the pocket.

[0032] According to a possible characteristic, said irregularities are constituted by surface undulations projecting towards said interior volume.

[0033] This implementation makes it possible to improve the cleaning in the pocket.

[0034] According to a possible characteristic, said pocket comprises at least one blade forming a projection inside said interior volume.

[0035] This implementation makes it possible to improve the cleaning in the pocket.

[0036] According to a possible characteristic, said pocket comprises a peripheral internal wall, at least one lateral blade extending from said peripheral wall towards the center of said pocket.

[0037] This implementation makes it possible to ensure rapid and efficient mixing of the reagent(s) with the molten metal contained in the ladle in a simple and economical manner.

[0038] According to a possible characteristic, at least two lateral blades extend opposite each other from said peripheral internal wall towards the center of said pocket.

[0039] This implementation makes it possible to further improve the mixing of the reactant(s) with the molten metal contained in the pocket.

[0040] According to a possible characteristic, said pocket comprises an internal bottom wall, at least one bottom blade extending from said internal bottom wall towards the center of said pocket.

[0041] This implementation makes it possible to ensure rapid and efficient mixing of the reagent(s) with the molten metal contained in the ladle in a simple and economical manner, and in particular to avoid stagnation of the reagents in the bottom of the ladle.

[0042] According to a possible characteristic, at least two bottom blades extend opposite each other from said internal bottom wall towards the center of said pocket.

[0043] This implementation makes it possible to further improve the mixing of the reactant(s) with the molten metal contained in the ladle, and in particular to avoid stagnation of the reactants in the bottom of the ladle.

[0044] According to a possible characteristic, said at least one side blade and said at least one bottom blade extend in sequential planes parallel to the axis of said pocket.

[0045] This allows a substantially uniform agitation gradient to be created in the bag to ensure efficient mixing of the reactants.

[0046] According to a possible characteristic, said at least one side blade extends beyond said at least one bottom blade.

[0047] In this case, a space is provided between the bottom blades and the side blades, the side blades extending above the bottom blades when the pocket is positioned such that its longitudinal axis extends vertically.

[0048] This implementation makes it possible to improve mixing in the pocket by generating currents which promote mixing.

[0049] According to a possible characteristic, said bottom and side blades form a U comprising a base extending from the bottom of said pocket and two wings extending along the axis of said pocket along said side internal wall.

[0050] This implementation also makes it possible to improve mixing in the pocket by generating currents promoting mixing.

[0051] According to a possible characteristic, said rotation drive means comprise a rotating table comprising a rotating plate with which said pocket is linked in rotation.

[0052] This implementation makes it possible to simply and robustly impart a rotational movement, linear or alternating, to the pocket to ensure effective mixing.

[0053] According to a possible characteristic, said rotary plate and said pocket comprise male / female elements capable of cooperating to connect said plate and said pocket in rotation.

[0054] This implementation can provide a simple and robust rotational connection. When the axes of the male / female elements are substantially parallel to the longitudinal axis of the pocket, this rotational connection can be easily provided without the bottom of the pocket resting on the rotating plate.

[0055] According to a possible characteristic, a device according to the invention comprises means for supporting said pocket, said support means taking up the weight of said pocket in such a way that it is not supported by said plate.

[0056] This implementation makes it possible to relieve the rotary plate and consequently to undersize the drive means used to print on the plate. a movement. This reduces the cost of the drive means (engine and transmission) and reduces their size.

[0057] According to a possible characteristic, said support means comprise a gantry comprising at least two feet capable of resting on the ground connected by at least one crosspiece, said pocket being connected to said crosspiece by a fixed pivot connection.

[0058] Such an implementation makes it possible to ensure, in a simple, robust and effective manner, a recovery of the forces of the pocket so as to relieve the rotary plate while allowing the rotation of the pocket.

[0059] According to a possible characteristic, a device according to the invention comprises a lifting beam, said pocket being connected to said lifting beam by a pivot connection along a second axis of rotation essentially perpendicular to said first axis of rotation.

[0060] This implementation can allow the pocket to be turned over to pour out the contents.

[0061] According to a possible characteristic, said spreader is secured to said gantry in a reversible manner.

[0062] This allows the pocket attached to the spreader bar to be separated from the gantry.

[0063] The invention also covers a method of treating a molten metal inside a pocket of a device according to any one of the above variants, said method comprising:

[0064] - a step of introducing said molten metal into said pocket;

[0065] - at least one treatment step comprising the injection of at least one reagent of treatment in said pocket;

[0066] - a step of rotating said pocket to mix said at least a reactant with said molten metal;

[0067] - a step of pouring the molten metal.

[0068] According to one variant, such a method comprises several successive processing steps.

[0069] According to a possible variant, the said treatment(s) belong(s) to the group comprising:

[0070] - desulfurization;

[0071] -initialization;

[0072] - nodularization;

[0073] - inoculation. 5. Description of figures

[0074] Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given as a simple illustrative and non-limiting example, and the appended drawings among which:

[0075] [Fig.l] [Fig.l] illustrates a perspective view of a treatment device according to the invention;

[0076] [Fig.2] [Fig.2] illustrates a top view of a pocket of the device of [Fig.l];

[0077] [Fig.3] [Fig.3] illustrates a sectional view along axis AA of [Fig.2];

[0078] [Fig.4] [Fig.4] illustrates a sectional view along the axis BB of [Fig.2];

[0079] [Fig.5] [Fig.5] illustrates a longitudinal sectional view of a variant of a pocket of a device according to the invention;

[0080] [Fig.6] [Fig.6] illustrates the diagram of a method according to the invention.

[0081] 6. Description of particular embodiments 6.1. Processing device

[0082] An example of a device for treating molten metal according to the invention is presented in relation to Figures 1 to 5.

[0083] Such a device comprises a pocket 1. Such a pocket 1 sometimes has the following names in the field of metallurgy depending on the context in which it is used:

[0084] - transfer pocket;

[0085] - casting ladle;

[0086] - treatment pocket.

[0087] For the sake of simplification, we will use here the term pocket which can indifferently ensure at least the functions of three types of pockets mentioned above.

[0088] In this embodiment, this pocket 1 is in the form of a cylinder provided with a peripheral wall 10 and a bottom 11. The pocket 1 is open at the end opposite the bottom 11 by an upper opening 12. This upper opening 12 has a pouring spout 13. It can be closed by means of a removable cover 2.

[0089] The pocket 1 comprises a peripheral internal wall 100 and an internal bottom wall 110 which delimit an interior volume 14 capable of containing molten metal. The molten metal may for example be cast iron, a ferrous alloy, a light alloy, a copper alloy or any other alloy or metal.

[0090] At least one blade 15, 16 projects inside the interior volume 14.

[0091] At least one side blade 15 extends from the peripheral inner wall 100 in direction of the center of the pocket 1, i.e. in the direction of its longitudinal axis A or its interior volume 14. In a first embodiment illustrated in Figures 2 to 4, the pocket 1 comprises two peripheral blades 15. These two blades 15 extend opposite each other from the peripheral internal wall 100 towards the center of the pocket 1. More than two peripheral blades 15 could be implemented. Where appropriate, they preferably extend two by two opposite each other.

[0092] The pocket 1 also comprises at least one bottom blade 16 extending from the internal bottom wall 110 towards the center of the pocket 1, i.e. towards its internal volume 14.

[0093] In this first embodiment, the pocket 1 comprises two bottom blades 16 extending opposite each other from the internal bottom wall 110 towards the center of the pocket 1. More than two bottom blades 16 could be implemented.

[0094] The side blades 15 and the bottom blades 16 extend in this embodiment in sequential planes passing through the longitudinal axis A of the pocket 1. These planes are here perpendicular to each other. They could however have another angle of inclination relative to each other.

[0095] The side blades 15 extend beyond the bottom blades 16. In other words, the side blades 15 extend, taken in a direction between the bottom 11 and the opening 12 of the pocket 1, after the bottom blades 16.

[0096] Each lateral blade 15 or bottom blade 16 projects towards the inside of the interior volume 14 over a distance between 1 / 30th and 1 / 2 of the inside diameter D of the pocket 1. Their width L along an axis in a first plane passing through the longitudinal axis A of the pocket 1 is between 1 / 30th and 1 / 2 of the inside diameter D of the pocket 1. Their length 1 along an axis in a second plane perpendicular to the first plane is between 1 / 30th and 1 / 2 of the inside diameter D of the pocket 1. Their height H along the longitudinal axis A of the pocket 1 is between 1 / 10th and 9 / 10th of the inside height Hi of the pocket 1.

[0097] The bottom blades 16 comprise an upper surface 161 opposite the bottom 11 inclined from the peripheral internal wall 100 towards the bottom 11. This upper surface 161 forms an angle α with the bottom 11 whose value is between 5 and 85°. In a variant, the upper surface 161 may be essentially parallel to the bottom 11.

[0098] The side blades 15 have an upper surface 151 and a lower surface 152. The upper surface 151 is here substantially parallel to the bottom 11. The lower surface 152 forms an angle [3 with the bottom 11 whose value is between 5 and 175°. In a variant, the lower surface 152 may be essentially parallel to the bottom 11.

[0099] Generally, the upper and / or lower surfaces of the side and / or bottom blades could be parallel to the bottom or inclined relative to it towards it or in an opposite direction from the peripheral inner wall.

[0100] The upper surface 151 of the side blades 150 is offset from the opening 12 towards the inside of the interior volume 14 of the pocket 1. In a variant, it could extend in the plane of the upper opening 12 of the pocket 1.

[0101] According to an alternative embodiment illustrated in [Fig.5], the bottom blades 16 and the side blades 15 form a U comprising a base 160 extending from the bottom 11 of the pocket towards the interior volume 14 and two side wings 150 extending along the longitudinal axis A of the pocket 1 along the peripheral internal wall 100. The side wings 150 can be interrupted to form lower portions 1500 and upper portions 1501, as shown in [Fig.5], or else be continuous.

[0102] The upper surface 151 of the upper portions 1501 of the side blades 150 extends in the plane of the upper opening 12 of the pocket 1. In a variant, they could be offset towards the inside of the pocket 1.

[0103] The upper surface 1502 of the lower portions 1500 of the side blades 150 and the lower surface 1503 of the upper portions 1501 of the side blades 150 are essentially parallel to each other and to the bottom 11. They could also be inclined relative to the bottom 11 and not be parallel to each other.

[0104] The device comprises means for driving the pocket 1 in rotation along at least a first axis of rotation. In this embodiment, this first axis of rotation is substantially the same as the longitudinal axis A of the pocket 1.

[0105] The rotation drive means comprise a turntable 17. This turntable 17 comprises a casing 170 and a rotary plate 171. The casing 170 houses a motor and a transmission (not shown) for driving the rotary plate 171 in rotation. The casing 170 also houses the motor control means (not shown). These control means make it possible in particular to program the rotation frequency of the rotary plate 171, its direction of rotation, the duration of the rotation cycles, etc.

[0106] The pocket 1 is linked in rotation with the rotary plate 171. For this, the rotary plate 171 comprises at least two, preferably three, drive shafts 1710 (male elements) which extend on its surface along axes parallel to the longitudinal axis A of the pocket 1. The pocket 1 comprises female housings 1720 which extend parallel to the longitudinal axis A of the pocket 1 and which are capable of receiving the drive shafts 1710 of the rotary plate 171. Thus, when the drive shafts 1710 of the rotary plate 171 and the female housings 1720 of the pocket 1 cooperate, the pocket 1 and the rotary plate 171 are linked in rotation along the longitudinal axis A of the pocket. 1

[0107] The device comprises means for supporting the pocket 1. These support means take up the weight of the pocket 1 in such a way that it is not supported by the rotary table 171. It is thus possible to reduce the size of the means for driving the pocket in rotation, in particular the rotary table 17.

[0108] In this embodiment, the support means comprise a gantry 18. This gantry 18 comprises at least two feet 180 capable of resting on the ground. These feet 180 are connected by at least one crosspiece 181.

[0109] The support means also comprise a spreader 19. This spreader 19 is in the form of an inverted U with two branches 190 connected by a crosspiece 191.

[0110] The pocket 1 is connected to the lever 19 by a pivot connection along a second axis of rotation B essentially perpendicular to the first axis of rotation A.

[0111] The support means comprise a hook 20. This hook 20 is connected to the crosspiece 181 of the gantry 18 by means of a rotating swivel 21. In other words, the hook 20 is connected to the crosspiece 181 of the gantry 18 by a fixed pivot connection with an axis essentially coincident with the longitudinal axis A of the pocket. 1

[0112] The hook 20 has a shape complementary to the crosspiece 191 of the spreader bar 19 so that when the hook 20 cooperates with the crosspiece 191 of the spreader bar 19, the hook 20 and the spreader bar 19 are linked in rotation along the longitudinal axis A of the pocket 1.

[0113] The pocket 1 is thus connected to the crosspiece 181 of the gantry 18 by a fixed pivot connection with an axis essentially coincident with the longitudinal axis A of the pocket 1 by means of the spreader bar 18 and the hook 20.

[0114] The height of the gantry 18 (i.e. of its crosspiece 181), the height of the hook 20, the height of the spreader bar 19, the height of the drive shafts 1710 of the rotary plate 171 and that of the female housings 1720 of the pocket 1 are chosen in such a way that a space separates the bottom 11 of the pocket 1 from the upper surface of the rotary plate 171 while guaranteeing that the drive shafts 1710 of the rotary plate 171 cooperate with the female housings 1720 of the pocket 1. Thus, the pocket 1 and the rotary plate 171 are linked in rotation without the rotary plate 171 supporting the weight of the pocket 1 which is taken up by the assembly comprising the spreader bar 19, the hook 20 and the gantry 18.

[0115] The implementation of the hook 20 makes it possible to ensure that the spreader 19 is secured to the gantry 18 in a reversible manner.

[0116] A device according to the invention can be housed in an enclosure 26 inside which it is possible to access by means of a gate 27.

[0117] Generally, the height H of the blades covers 5 to 90% of the internal height Hi of the pocket. The width L of the blades covers 3 to 50% of the internal diameter D of the pocket. The length 1 of the blades covers 5 to 90% of the internal radius of the pocket, i.e. D / 2. 6.2. Variants

[0118] In variants, the pocket may not include a blade.

[0119] In variants, the peripheral inner wall of the pocket may have surface irregularities.

[0120] These surface irregularities can be due to the rough appearance of the pocket molding. Thus, the inner surface of the pocket is not smooth but has roughness a bit like abrasive paper. Such an appearance can be implemented even when blades are implemented.

[0121] The irregularities may also be constituted by at least one element forming a projection towards the interior volume of the pocket. This at least one element may be a blade or other.

[0122] The irregularities may consist of surface undulations protruding towards the interior volume. 6.3. Single-pocket treatment process

[0123] A treatment device according to the invention can be implemented to ensure the treatment of a molten metal. The molten metal can be:

[0124] - a pure metal;

[0125] - a cast iron;

[0126] - a ferrous alloy;

[0127] - a copper alloy;

[0128] - a light alloy;

[0129] - any other metal or metal alloy.

[0130] With reference to [Fig.6], such a method comprises:

[0131] - a step 22 of introducing molten metal into the pocket 1 from a oven ;

[0132] - at least one processing step 23 comprising:

[0133] - a step 230 of injecting at least one treatment reagent into the pocket 1;

[0134] - a step 231 of rotating the bag 1 to mix the at least a reactant with the molten metal;

[0135] - a step 24 of pouring the molten metal.

[0136] The treatment may for example belong to the group comprising:

[0137] - desulfurization;

[0138] - initialization;

[0139] - nodularization;

[0140] - inoculation.

[0141] The method preferably comprises several successive treatment steps. In particular, the method may successively comprise a step of introducing molten metal into the ladle, a desulfurization step, an initialization step, a nodularization step, an inoculation step then a step of casting the treated metal into a mold to produce a foundry part.

[0142] All treatment steps take place inside the same pocket, unlike the prior art where each treatment is carried out in a different pocket.

[0143] The ladle rotation step, due to the presence of the blades, ensures effective mixing of the reagent(s) with the molten metal. This improves the yield and effectiveness of the treatments.

[0144] Using a single ladle to carry out all the treatments makes it possible to avoid pouring, at the end of each treatment step, the contents of the ladle into another ladle dedicated to the following treatment. As a result, heat losses are reduced and the yield of the metal, which retains a high temperature, is consequently improved.

[0145] Considering that the yield is increased, the processing capacity of the ladle increases so that it is possible to increase its internal volume and process a larger quantity of metal simultaneously.

[0146] Increasing the volume of the ladle improves the efficiency of the furnace. In fact, it is then possible to empty the furnace more frequently and to refill it more frequently to prepare the new molten metal.

[0147] The use of a single bag makes it possible to reduce the size of the treatment installation as well as its cost.

Claims

Claims

1. Device for treating a molten metal, said device comprising a pocket defining an interior volume intended to contain said molten metal, in which said device comprises means for driving said pocket in rotation along at least a first axis of rotation, characterized in that said pocket comprises at least one blade projecting inside said interior volume.

2. A device according to claim 1 wherein said pocket comprises a peripheral inner wall having surface irregularities.

3. Device according to claim 2 wherein said irregularities are constituted by at least one element forming a projection in the direction of said interior volume.

4. Device according to any one of the preceding claims wherein said pocket comprises a peripheral internal wall, at least one side blade extending from said peripheral wall towards the center of said pocket.

5. Device according to claim 4 in which at least two lateral blades extend opposite each other from said peripheral internal wall towards the center of said pocket.

6. A device according to any one of claims 1 to 5 wherein said pocket comprises an internal bottom wall, at least one bottom blade extending from said internal bottom wall towards the center of said pocket.

7. Device according to claim 6 in which at least two bottom blades extend opposite each other from said bottom internal wall towards the center of said pocket.

8. Device according to any one of the preceding claims, claims 4 and 6, alone or in combination with any one of claims 5 and 7, wherein said at least one side blade and said at least one bottom blade extend in sequential planes parallel to the axis of said pocket.

9. A device according to claims 4 and 6, alone or in combination with any one of claims 5, 7 or 8, wherein said at least one side blade extends beyond said at least one bottom blade.

10. Device according to claims 4 and 6 wherein said bottom and side blades form a U comprising a base extending from the bottom of said pocket and two wings extending along the axis of said pocket along said side internal wall.

11. Device according to any one of claims 1 to 10 wherein said rotational drive means comprise a rotating table comprising a rotating plate with which said pocket is rotationally linked.

12. Device according to claim 11 wherein said rotating plate and said pocket comprise male / female elements capable of cooperating to connect said plate and said pocket in rotation.

13. Device according to claim 11 or 12 comprising means for supporting said pocket, said support means taking up the weight of said pocket in such a way that it is not supported by said plate.

14. Device according to claim 13 wherein said support means comprise a gantry comprising at least two feet capable of resting on the ground connected by at least one crosspiece, said pocket being connected to said crosspiece by a fixed pivot connection.

15. Device according to claim 14 comprising a lifting beam, said pocket being connected to said lifting beam by a pivot connection along a second axis of rotation essentially perpendicular to said first axis of rotation.

16. Device according to claim 15 in which said lifting beam is secured to said gantry in a reversible manner.

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