Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
  • B22D11/0637—Accessories therefor
  • B22D11/0665—Accessories therefor for treating the casting surfaces, e.g. calibrating, cleaning, dressing, preheating
  • B22D11/0668—Accessories therefor for treating the casting surfaces, e.g. calibrating, cleaning, dressing, preheating for dressing, coating or lubricating

Definitions

• the invention relates to the continuous casting between rolls of metal strips, in particular aluminum or aluminum alloy strips. It relates more particularly to a method and a device for poteying said cylinders during casting.
• Continuous casting between cylinders is a well-known technique for producing metal strips from a source of liquid metal.
• liquid metal is injected into the air gap separating two rotating metal cylinders, solidifies on contact with them and leaves in the solid state, in the form of a strip.
• the solidified metal partially adheres to the surface of the rolls, which leads to a deterioration in the quality of the strip, or even to stopping the casting.
• a liquid coating product also called “lubricant”
• the poteyage product is often a mixture of water and graphite particles.
• the coating is normally applied continuously, that is to say that the working surface of a cylinder is coated substantially continuously with the coating product.
• Known poteyage devices include one or more projection means per cylinder which can be fixed or mobile.
• French applications FR 2498 099 (corresponding to American patent US 4,501,315) and FR 2,621,839 (corresponding to American patent US 4,892,133) describe potage devices with adjustable flow rate comprising distribution ramps for the product of potage provided with projection means arranged linearly along the cylinders.
• the international patent application WO 95/09707 describes a coating device provided with spray nozzles for the coating product aligned along the cylinders and grouped by zones, each zone being supplied separately with coating product as a function of the width of the strip. metallic. A part of the nozzles can be driven in an oscillatory movement parallel to the axis of the cylinders.
• the Applicant has therefore sought solutions to improve the coating of cylinders for machines for continuously casting metal strips.
• the subject of the invention is a method for coating the cylinders of a continuous casting machine between cylinders in which at least one coating product containing a coating agent is applied, such as a graphite suspension, which is characterized in that that it comprises an adjustment of the composition of said poteyage product being applied to said cylinders.
• the invention also relates to a continuous casting process between cylinders of metal strips comprising a coating process according to the invention.
• the invention also relates to a device for poteying the cylinders which is suitable for use on a continuous casting machine between cylinders, which comprises means for applying at least one poteyage product and which is characterized in that it comprises means for adjusting the composition of said poteyage product during application on said cylinders.
• the invention also relates to a continuous casting machine between cylinders of metal strips equipped with a coating device according to the invention.
• the invention also relates to a method for regulating a continuous casting machine between rolls of metal strips comprising the application of at least one coating product to said cylinders, said coating product containing a coating agent, such as that of graphite, which is characterized in that it comprises an adjustment of the composition of said poteyage product being applied to said cylinders. Said adjustment is advantageously carried out according to the operating conditions of said machine.
• Said continuous casting can be horizontal, inclined with respect to the horizontal or vertical (ascending or descending).
• the applicant sought to control the quantity and the distribution of the coating product which is deposited on the working surface of the cylinders.
• the changes in the flow rate of the projection means modified not only the quantity of poteyage product deposited on the cylinders but also the distribution of said product on their surface. of work, with the consequence, in particular, of uncontrolled variations in the efficiency of the coating, in particular as regards the stability of the casting machine and the quality of the strip produced.
• variations in the flow rate of the spraying agent sprayed onto the working surface of a cylinder by projection means can produce variations in the distribution of the spraying agent inside the spraying cone or “jets” and on the impact surface, whereas, in general, variations in the composition of the coating product do not modify said distribution significantly.
• the applicant had the idea of adjusting the composition of the coating product during application, which makes it possible to adjust the amount of coating agent supplied to the surface of the coating. cylinder while limiting the heterogeneities of distribution of said agent.
• the poteyage product can be a suspension, a solution or a mixture thereof.
• FIG. 1 schematically represents, seen from the side, a continuous casting machine between cylinders provided with poteyage means typical of the prior art.
• Figure 2 is a schematic representation of a potage device of a continuous casting machine between cylinders of the prior art.
• Figure 3 is a schematic representation of a preferred embodiment of a poteyage device of a continuous casting machine between cylinders according to the invention.
• FIG. 4 schematically represents variants of a part of the potaging device of a continuous casting machine between rolls according to the invention.
• FIG. 5 illustrates the influence of a variation in the spray of plastering product from juxtaposed projection means on the distribution of plastering product on the surface of a cylinder.
• FIG. 6 illustrates the influence of a variation in the spraying of plastering product of juxtaposed projection means on the distribution of plastering product on the surface of a cylinder in the case of a strong overlap between the jets.
• FIG. 7 schematically represents, seen from the side, a continuous casting machine between cylinders provided with poteyage means according to a possible embodiment of the invention.
• Figure 8 is a simplified representation, seen from above, of a continuous casting machine between cylinders provided with poteyage means according to a possible embodiment of the invention.
• Figure 9 is a simplified representation, seen from above, of a continuous casting machine between cylinders provided with poteyage means according to a possible embodiment of the invention.
• a machine (1) for continuous casting between cylinders typically comprises two horizontal cylinders (1 A, IB) and an injector (2).
• the cylinders (1A, IB) are typically made of metal and generally have the same diameter.
• the axes of rotation (A, B) of the cylinders (1A, IB) are generally substantially parallel to each other.
• the cylinders are separated by an air gap (13) and are able to rotate in opposite directions with respect to each other.
• the liquid metal (3) is introduced on one side of the air gap (13) using the injector (2) and leaves the other side in the solid state, in the form of a strip. (4) having a nominal thickness Eo which is substantially equal to the opening E of the air gap (13).
• the surface (10) of the cylinders is continuously cooled, typically using a coolant circulating inside the cylinders.
• the casting is said to be horizontal when the center distance AB between the cylinders (1A) and (IB) is substantially vertical. It is said to be inclined when said center distance AB is inclined relative to the vertical. It is said to be vertical when said center distance AB is substantially horizontal.
• a continuous casting machine between rolls is normally provided with coating means typically comprising projection means (5) of the coating product (24), support means (7, 8) of said projection means, a source (22) of cleaning product (24), an agitator (23), pipes (6, 21) for conveying the cleaning product (24) and a means (20) for regulating the flow of the cleaning product.
• the source (22) of poteyage product is typically a reservoir with a capacity of the order of 100 to 200 liters.
• the method for coating the rolls (1A, IB) of a machine (1) for continuous casting between rolls comprises applying at least one coating product (24) to said rolls, said coating product poteyage containing a poteyage agent and a carrier fluid, and is characterized in that it comprises an adjustment of the composition of said poteyage product (24) being applied to said cylinders.
• the invention is based on the idea of varying the composition of the coating product in order to avoid variations in the size of the jets and in the distribution of the coating agent inside the spray cone or “jets” ( 9, 91, 92) and on the impact surface (100, 101, 102) which can appear when the flow rate of the projection means (5, 51, 52) is varied.
• the coating agent preferably comprises graphite, typically in the form of micron particles.
• the carrier fluid preferably comprises water.
• the graphite is suspended in the carrier fluid, optionally in colloidal form, with a concentration which is typically between 0.2 and 4% by weight.
• said adjustment of the composition comprises an adjustment of the proportion of potting agent contained in the potting product, that is to say of the concentration of potting agent of said product poteyage.
• the adjustment of the composition comprises a dilution of a concentrate of potting agent in a carrier fluid.
• Said concentrate can be a "mother suspension", a concentrated solution or a mixture thereof.
• Said concentrate is advantageously chosen from concentrated suspensions of graphite, boron nitride, colloidal silica, magnesia, organic products (such as organic oils or polyesters) or a mixture of these.
• a mother suspension which is a concentrate of graphite particles suspended in a gel, with a proportion of graphite typically between 20 and 30% by weight.
• the carrier fluid is then generally water.
• the proportion of mother suspension added to the carrier fluid is typically between 1 and 8%.
• the method according to the invention also comprises an adjustment of the flow rate of the coating product so as to obtain a stability of the jet over time, in particular between the moment when the guns are adjusted relative to the cylinders , outside casting, and during casting.
• the adjustment of the composition can be carried out retroactively as a function of measurements carried out on the casting machine (1) (typically using a control loop) and / or in an automated manner.
• Said measurements typically include measurements chosen from optical, laser, infrared, vibration or mechanical tension measurements.
• the amount of potting agent present on the surface (10) of the cylinders can be determined using a detector (such as an optical detector, a laser system, a camera or an infrared detector) which produces a signal which can be used in feedback to regulate the composition of the poteyage product.
• Said adjustment of the composition can then correspond to regulation.
• the process of the invention can be included in a process for regulating a continuous casting machine between rolls.
• the device for poteying a cylinder (1A, IB), which is suitable for use on a continuous casting machine between cylinders, comprises coating means (5, 51, 52, 6, 61 , 62, 7, 8, 20, 21) for applying at least one coating product (24) to said cylinders and is characterized in that it comprises means (30 to 41) for adjusting the composition of the coating product in course of application on said cylinders.
• the coating device according to the invention is capable of implementing the coating method of the invention.
• the coating means advantageously comprise means (20) for controlling the flow rate of the projection means (5, 51, 52), such as a positive displacement pump.
• the conduits (6, 21) can be made of different materials compatible with the coating product and the ambient conditions of a continuous casting machine.
• a part (6) of the conduits is preferably flexible.
• the coating means can be placed at different locations on the periphery of the cylinders. They are however advantageously placed on the outlet side, that is to say on the side of the metal strip, so as not to be in contact with the liquid metal, which could lead to risks of explosion.
• the coating product comprises a carrier fluid, such as water, and a solid coating agent, such as graphite
• the coating means according to the invention can also comprise means (38, 39), active or passive, such as an agitator (38) or a baffle (39), to homogenize the cleaning product.
• the coating means according to the invention may optionally include means (38) for keeping the particles of coating agent in suspension.
• said means for adjusting (30 to 41) the composition of the coating product include a mixer (40), a supply of coating agent ( 41), a means of regulation (32) of the supply of potentage agent and a supply of carrier fluid (30).
• the regulating means (32) makes it possible to control and regulate the quantity of potetting agent which is supplied to the mixer (40) and applied to the cylinders by the coating means.
• the regulating means (32) may include, for example, a metering pump.
• Said mixer (40) can also be a Nenturi, a buffer tank or a pot.
• the mixer (40) is advantageously of very low capacity (for example from 1 to 2 liters), which in particular makes it possible to quickly vary the concentration of potting agent contained in the potting product.
• the mixer (40) can be common to several projection means.
• FIG. 4 illustrates two embodiments of said adjustment means (30 to 41).
• said adjustment means (30 to 41) comprise a reservoir (34) capable of containing said concentrate (35), a means of regulation (32) of the supply of poteyage, piping means (31, 33), a supply of carrier fluid (30), a buffer tank (36) capable of containing the poteyage product (24), a mixing zone (37) and an agitator (38 ).
• a reservoir (34) capable of containing said concentrate (35)
• a means of regulation (32) of the supply of poteyage piping means (31, 33), a supply of carrier fluid (30), a buffer tank (36) capable of containing the poteyage product (24), a mixing zone (37) and an agitator (38 ).
• said adjustment means (30 to 41) comprise a reservoir (34) capable of containing said concentrate (35), a means of regulation (32) of the supply of poteyage, means of pipelines (31, 33), a supply of carrier fluid (30), a pot (36) capable of containing the cleaning product (24), a mixing zone (37), baffles (39) and an agitator (38) .
• the Applicant has had the idea that the dilution of a concentrate of potting agent in a carrier fluid in a mixer (40), in particular when the latter is of low capacity, could make it possible to avoid the problems of sedimentation of the potting agent which are often observed with known devices (which generally operate in “batch” mode using large-capacity tanks (22), as seen typically between 100 and 200 liters) and which cause fluctuations in the actual composition of the coating product compared to the nominal value.
• the use of one or more mixers (40) of low capacity also makes it possible to reduce their volume and, consequently, the size of the casting installations. It also simplifies orders.
• the supply of coating agent (41) advantageously comprises a reservoir (34), starting from from which the mixer (40) can be supplied in a regulated manner.
• the means (30 to 41) for adjusting the composition of the coating product can form an adjustment device (42) which is advantageously distinct, removable and / or removable, which facilitates maintenance.
• the coating device of the invention can comprise means for retroactively controlling said adjustment of the composition as a function of measurements carried out on said casting machine, for example using a regulation loop. It can also include means for automatically controlling said adjustment of the composition.
• the projection means (5, 51, 52) are typically chosen from the group comprising nozzles and guns.
• the coating means may include a only one projection means (5) per cylinder ( Figure 1) or more projection means (51, 52) per cylinder ( Figures 7 and 9). In the latter case, the projection means can be superimposed (as illustrated in FIG. 7) or distributed along the cylinder (as illustrated in FIG. 9).
• the coating means may also include means for moving the projection means along the cylinder, typically in an oscillating movement or in a reciprocating movement between one end (11) and the other (12 ) of the cylinder.
• said coating means comprise a projection means (5) for each cylinder (1A, IB) and means (80 to 84) for moving said projection means (5) along each cylinder, typically in a back and forth movement.
• said coating means comprise at least two projection means (51, 52) for each cylinder (1 A, IB), said projection means forming an integral assembly, and means ( 80 to 84) to move each said together along each cylinder, typically in a reciprocating motion.
• the projection means of each said assembly are advantageously superimposed, as illustrated in FIG. 7, when it is sought to produce strips of large width (which is normally made difficult by the limited maximum speed of the means of displacement of the means projections).
• the displacement means (80 to 84) typically comprise a mobile support or carriage (80), a rail (81) and drive means (82, 83, 84) such as a motor.
• said displacement means (80 to 84) make it possible to move said projection means in a reciprocating movement along an axis parallel to the axis (A, B) of the cylinder.
• said coating means comprise at least two projection means (5) for each cylinder and said projection means are arranged on a line substantially parallel to the axis (A, B) of each said cylinder (1A, IB).
• the projection means are typically equidistant.
• the orientation of the projection means can be fixed or variable.
• the device according to the invention may also include means for oscillating at least one of the projection means with respect to a determined axis, which makes it possible to increase the impact surface of the projection means and, optionally, to decrease the number.
• the axis of oscillation is typically vertical.
• the invention is particularly advantageous in the case where at least two projection means are used per cylinder.
• the overlap of the projection cones (9, 91, 92) and the impact surfaces (100, 101, 102) can cause significant variations in the distribution of the total coating agent.
• multiple means of projection For example, as illustrated diagrammatically in FIG. 5, where D represents the surface density of the coating agent, the total impact surface of two juxtaposed projection means can undergo not only radial variations in density, as c is the case of a single projection means, but also very large variations in density in the contact zone between the projection cones and the impact surfaces, even if the coating may be close to the nominal value N in S zones where the impact surfaces do not overlap.
• FIG. 5a corresponds to the case where the two jets form a relatively closed angle with respect to the desired optimal value; the overlap between the projection cones and the two impact surfaces is in this case very low or zero, which leads to underpotting areas E with respect to the nominal value N.
• FIG. 5b) corresponds to the case where the two jets form a relatively open angle with respect to the desired optimal value; the overlap between the projection cones and the two impact surfaces is in this case not insignificant, or even significant, which leads to overpotting areas R with respect to the nominal value N.
• FIG. 6 shows that a similar effect can occur even if the overlap areas between the impact surfaces are very large.
• the amount of coating applied in certain zones can fluctuate very significantly, passing from under-coating in certain zones T when the angle of the jets is relatively closed with respect to the desired optimal value (FIG. 6a) to an overpotting in the same zones T when the angle of the jets is relatively open (FIG. 6b).
• the machine (1) for continuous casting between cylinders according to the invention can comprise at least one detector for determining the quantity of potentage agent present on the surface (10) of the cylinders which produces a signal suitable for being used in feedback to adjust the the composition of the poteyage product.
• Said detector is typically chosen from optical detectors, laser systems, cameras, infrared detectors, vibration detectors and mechanical tension detectors.
• said adjustment can be made as a function of the operating conditions of said machine (1). It can also be carried out retroactively as a function of measurements carried out on said casting machine, for example using a regulation loop. Said measurements can include measurements chosen from optical, laser, infrared, vibration or mechanical tension measurements. Said adjustment of the composition can also be carried out automatically.
• the invention relates above all to the production of strips of non-ferrous metals, in particular aluminum or aluminum alloy or copper or copper alloy.
• the quality of the surface of the strips was verified by a macrographic attack on full-width samples.
• the Applicant has noted a significant improvement in quality of the surface of the strips, greater reproducibility of this quality and a productivity of about 10% higher than that observed for casting carried out with a batching in batch mode, with large capacity tanks and a simple adjustment of the product flow rate poteyage. She attributes these improvements to a more uniform and better controlled distribution of potting agent.
• the invention which can be integrated into the methods and devices for continuous casting between existing rolls, makes it possible to improve the quality of the strips obtained and the consistency of the coating on the rolls.
• the quality is notably improved by the adjustment of the jets which can remain the same whatever the operating range of the machine.
• the consistency of the deposit makes it possible to significantly limit the quantity of poteyage product necessary to obtain strips of determined quality.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Coating Apparatus (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Continuous Casting (AREA)
• Rollers For Roller Conveyors For Transfer (AREA)
• Lubricants (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Devices For Post-Treatments, Processing, Supply, Discharge, And Other Processes (AREA)
• Casting Devices For Molds (AREA)

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• 2001
  • 2001-02-08 FR FR0101724A patent/FR2820350B1/fr not_active Expired - Lifetime
• 2002
  • 2002-02-05 TR TR2004/01358T patent/TR200401358T4/xx unknown
  • 2002-02-05 BR BR0207027-8A patent/BR0207027A/pt not_active Application Discontinuation
  • 2002-02-05 CN CN02804677.3A patent/CN1263567C/zh not_active Expired - Lifetime
  • 2002-02-05 AT AT02703655T patent/ATE268238T1/de not_active IP Right Cessation
  • 2002-02-05 EP EP02703655A patent/EP1358029B1/de not_active Expired - Lifetime
  • 2002-02-05 JP JP2002562502A patent/JP2004532127A/ja active Pending
  • 2002-02-05 ES ES02703655T patent/ES2219630T3/es not_active Expired - Lifetime
  • 2002-02-05 RU RU2003127068/02A patent/RU2288068C2/ru not_active IP Right Cessation
  • 2002-02-05 IL IL15673202A patent/IL156732A0/xx active IP Right Grant
  • 2002-02-05 CA CA002438038A patent/CA2438038C/fr not_active Expired - Lifetime
  • 2002-02-05 MX MXPA03006997A patent/MXPA03006997A/es active IP Right Grant
  • 2002-02-05 DE DE60200587T patent/DE60200587T2/de not_active Expired - Lifetime
  • 2002-02-05 WO PCT/FR2002/000441 patent/WO2002062508A1/fr active IP Right Grant
  • 2002-02-05 CZ CZ20032247A patent/CZ296422B6/cs not_active IP Right Cessation
• 2003
  • 2003-07-01 IL IL156732A patent/IL156732A/en not_active IP Right Cessation
  • 2003-08-05 NO NO20033477A patent/NO20033477L/no not_active Application Discontinuation

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