Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/14—Closures
  • B22D41/22—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings
  • B22D41/38—Means for operating the sliding gate
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/14—Closures
  • B22D41/22—Closures sliding-gate type, i.e. having a fixed plate and a movable plate in sliding contact with each other for selective registry of their openings
  • B22D41/42—Features relating to gas injection

Definitions

• Drawer device for a tank containing molten metal Drawer device for a tank containing molten metal.
• the present invention relates to a drawer device for a tank containing a molten metal.
• the invention relates to a shutter assembly with a movable drawer which is disposed on an upstream container used in metallurgy to allow the flow of liquid metal to a downstream container.
• the refractory bags used in metallurgy, and more particularly in the steel industry, for the casting of molten metals in a downstream container made up in particular of a continuous casting distributor, a mold or another pocket, are partly fitted.
• lower shutters with movable drawer which, when opened, allow the casting operation.
• the refractory lining of the bottom of the pocket which contains the molten metal is pierced directly above the drawer and is provided with a funnel in communication via a nozzle with the orifice of a fixed plate of material refractory. Under this fixed plate slides a movable plate or drawer, also made of refractory material and pierced with a hole. The metal is poured when the two holes are superimposed.
• This opening / closing device requires the production of a good quality seal between the fixed plate and the movable plate forming the drawer. In known solutions, this tightness is obtained by using plates whose working faces are perfectly smooth, generally rectified and strongly tightened one against the other by return means.
• the drawer device for a tank containing a molten metal which comprises a fixed body defining an internal housing with an upstream wall and a downstream wall, each wall being provided with an orifice, said orifices being opposite one another and a movable drawer mounted in said housing, said drawer having at least one orifice between its main faces, said drawer being guided in movement by said housing between at least a first position in which the orifice of the drawer is not opposite the orifices of said body and at least a second position in which the orifice of the drawer is opposite the orifices of the body, a clearance existing between the main faces of said drawer and the internal wall of the housing is characterized in that it further comprises:
• the seal between the drawer itself and the fixed body of the drawer is produced by a flow of pressurized gas produced by two pressure sources so as to obtain a seal regularly distributed over the whole facing surfaces of the fixed and mobile parts of the drawer device. It is understood that thus, the seal is obtained without the need to apply a large force between the fixed part and the movable part. On the contrary, a clearance is provided between these two parts of the drawer device.
• This gas pressure must be sufficient to compensate for the static pressure of the metal contained in the upstream container.
• at least one of the movements of the drawer between its open position and its closed position or between its closed position and its open position is also ensured by a pressurized gas.
• the reverse movement to that caused by the first flow of pressurized gas is also obtained by a second flow of pressurized gas. It is understood that thus, no mechanical organ is necessary.
• the second movement of movement of the drawer is obtained by controllable mechanical means. It is understood, however, since the seal between the fixed part and the mobile part of the drawer device is obtained by a gas flow, that the force to be applied to move the drawer is significantly reduced compared to the solutions of the prior art.
• the gas flows serve only for sealing and the movements of the drawer are produced by mechanical means.
• the displacement of the drawer itself can be rectilinear but that this displacement can also be a movement of rotation around a fixed axis of the drawer.
• FIG. la is a sectional elevation view of a first embodiment of the rectilinear displacement drawer device
• - Figure lb is a sectional view along line BB of Figure la;
• - Figure 2a is a sectional elevational view of an alternative embodiment of the rectilinear displacement drawer device;
• Figure 2b is a sectional view along line BB of Figure 2a;
• FIG. 3a is a sectional elevational view of a second alternative embodiment of the rectilinear movement drawer device; - Figure 3b is a sectional view along line BB of the figure
• - Figure 4a is a sectional elevation view of a circular displacement drawer device; and - Figure 4b is a sectional view along line BB of Figure 4a.
• FIG. 1 a the bottom of the reservoir 10 is shown with its ferrule or internal nozzle 12 in which the tap hole 14 is formed.
• the drawer device which bears the general reference 16 is mounted below the tap hole 14 for allow it to be opened or closed.
• the drawer device comprises a fixed body essentially constituted by a lower part 18 and by an upper part 20 connected together.
• the lower 18 and upper 20 parts are each provided with a vertical orifice 22 and 24 which are themselves aligned with the pouring orifice 14.
• the upper 20 and lower 18 parts define between them a housing 26 of generally rectangular parallelepiped shape in which the shutter drawer 28 can move.
• the drawer 28, in this embodiment, is equipped with a hole 30 so that, when the drawer is brought into its position shown in FIGS. 1 a and 1 b, the hole 30 is opposite the holes 22 and 24 allowing the flow of liquid metal, on the other hand, when the drawer 28 is moved away from this position, it closes the orifices 22 and 24.
• the body 18, 20 as well as the drawer 28 are preferably made of metal and partly of refractory material. The latter is able to thermally and chemically resist the metal which passes through it.
• the refractory material may be nitride binder alumina doped with boron nitride and / or graphite, mullite binder tabular alumina products, sintered magnesia products, tabular alumina products and thermosetting resins, bauxite or chamotte products.
• the drawer 28 which also has a substantially rectangular parallelepiped shape is guided in translation by the cooperation of its longitudinal edges 32 and 34 with the internal walls longitudinal 36 and 38 of the internal housing 26.
• the drawer has an upper face 28a and a lower face 28b opposite the upper and lower main faces of the housing 26.
• This clearance is preferably between 0.01mm and 2mm.
• Two nozzles 40 and 42 respectively are provided at the ends of the housing 26, so that these nozzles open into the housing 26 opposite the ends 28c and 28d of the drawer.
• These nozzles 40 and 42 are connected to sources of pressurized gas by means of regulation valves such as 44 and 46.
• the valves 44 and 46 are controlled by a control circuit 48.
• This control circuit 48 makes it possible to adjust the valves 44 and 46 and therefore the gas pressure delivered by the nozzles 40 and 42. It is understood that, depending on the value of the pressures P 1 applied to the nozzle 42 and the pressure P 2 applied to the nozzle 40, it is possible to control the movement of the drawer 28 between its closed position and its open position.
• the gas jets delivered by the nozzles 40 and 42 create a gas flow, in particular in the clearances provided between the upper and lower faces and the internal bars of the housing. These gas flows thus make it possible to produce a seal between the drawer and the internal walls of the housing. It should be emphasized that, due to the presence of 2 opposing gas flow sources, a very good distribution of the gas flow is obtained and therefore an effective seal. It is therefore understood that, in this first embodiment, the 2 gas flows play the double function of constituting a sealing curtain between the drawer and the housing and of allowing the drawer to be moved in one direction and the other by adjustment respective pressures P 1 and P 2 . The value of these pressures is adapted as a function of the metallostatic load exerted on the slide. In addition, if the pressure is sufficient, this gas flow can be used for the treatment of gas bubbling in the upstream container.
• FIGS. 1a and 1b we will describe a first alternative embodiment of the drawer device.
• This variant differs essentially from that of FIGS. 1a and 1b by the fact that it a mechanical stop 50 is provided which projects into the underside of the housing 26 in which the drawer 28 moves.
• This stop 50 is arranged in such a way that, when the end 28d of the drawer is in contact with the stop 50, the drawer is in the open position, that is to say that its orifice 30 is opposite the orifices 24 and 22 of the body of the drawer device.
• This mechanical stop makes it possible to precisely adjust this open position. It allows quick and reliable adjustment in an open position defined in advance.
• the stop 52 has an end 54 forming a cam which is disposed inside the housing 26.
• a reference position is defined for the drawer.
• the gas jet on the drawer which brings its end 28d into contact with the cam 54 controls the opening of the drawer. Its closure can be obtained by the pressure P 2 applied by the nozzle 42.
• the two gaseous flows created in the body of the shutter with a drawer serve first of all to seal between the drawer and the body of the shutter and then to cause at least one of the two movement movements. of the drawer.
• the invention would not be departed from if the gas flows were used only for sealing, the displacements of the slide being obtained by mechanical means controlled manually or using a jack. It is understood that, even in this embodiment, the control of the movements of the drawer is greatly facilitated by the invention since the forces to be exerted are reduced due to the sealing system used.
• the movement of the drawer, to move it from an open position to a closed position is a rectilinear movement. In certain cases, it may be advantageous to provide for a displacement of the drawer according to a rotational movement around its own axis.
• the periphery 60a of the circular drawer 60 is equipped with radial fins such as 62, these fins having a free edge 62a close to the internal cylindrical wall 64a of the housing 64 in which the rotary drawer is mounted.
• two nozzles 66 and 68 are provided to create a gas pressure in the housing 64, these nozzles open into the housing at points substantially diametrically opposite with respect to the axis of rotation XX '.
• these nozzles 66 and 68 open out with a slight inclination relative to the wall of the housing 64.
• This gas pressure produced by the two nozzles makes it possible to control the rotation of the drawer in the direction of the arrow F.
• These gas jets also make it possible to perform the sealing function between the movable drawer and the walls of the housing.
• the rotation movement in the opposite direction can be obtained by means of an additional nozzle 76 acting on the fins 62 in the opposite direction of rotation. It is also possible to provide a braking finger 78 to stop the rotary slide in its desired angular position.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9489596

Family Applications (1)

Country Status (8)

Families Citing this family (4)

Family Cites Families (4)

• 1996
  • 1996-02-27 FR FR9602382A patent/FR2745209B1/fr not_active Expired - Fee Related
• 1997
  • 1997-02-19 ZA ZA9701406A patent/ZA971406B/xx unknown
  • 1997-02-26 WO PCT/FR1997/000339 patent/WO1997031737A1/fr not_active Application Discontinuation
  • 1997-02-26 AU AU19289/97A patent/AU1928997A/en not_active Abandoned
  • 1997-02-26 BR BR9707784A patent/BR9707784A/pt not_active Application Discontinuation
  • 1997-02-26 EP EP97907130A patent/EP0883454A1/fr not_active Ceased
  • 1997-02-26 JP JP09530665A patent/JP2001501535A/ja active Pending
  • 1997-02-27 TW TW086102438A patent/TW330869B/zh active

Non-Patent Citations (1)

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