EP0332483B1 - Nozzle for assisting orifice,device incorporated therein and method for method for carrying out - Google Patents

Nozzle for assisting orifice,device incorporated therein and method for method for carrying out Download PDF

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Publication number
EP0332483B1
EP0332483B1 EP89400411A EP89400411A EP0332483B1 EP 0332483 B1 EP0332483 B1 EP 0332483B1 EP 89400411 A EP89400411 A EP 89400411A EP 89400411 A EP89400411 A EP 89400411A EP 0332483 B1 EP0332483 B1 EP 0332483B1
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EP
European Patent Office
Prior art keywords
nozzle
pressure
opening
gas
nozzle according
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EP89400411A
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German (de)
French (fr)
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EP0332483A1 (en
Inventor
Eric Hanse
Gilbert Rancoule
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Vesuvius France SA
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Vesuvius France SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • B22D1/002—Treatment with gases
    • B22D1/005—Injection assemblies therefor
    • 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
    • B22D41/50—Pouring-nozzles
    • B22D41/58—Pouring-nozzles with gas injecting means

Definitions

  • the present invention relates to a casting nozzle with assisted opening, it also relates to ladles fitted with such a nozzle and to the means of using such a nozzle.
  • the molten metal is transported either to treat it metallurgically as for example in continuous casting, or to lead it to refining operations, or for any other reason, by means of containers called pockets.
  • the transfer of liquid metal from the pocket to the tool where the metal is to be treated, is done either by pouring, or by means of tap holes most often fitted with a nozzle.
  • the opening of tap holes is a general problem, often difficult to solve, especially when the metal is a metal or an alloy with a high melting point, such as iron and various steels whose melting point is close to that iron.
  • the continuous casting bags are equipped with a nozzle arranged at the bottom of the bag and held by a refractory system.
  • This nozzle has in its center a cylindrical opening through which the molten metal flows.
  • the closure system of this opening is generally of the drawer type.
  • the opening of the nozzle is filled with a sand generally formed of refractory material, and this sand is allowed to overflow in the upper part of the nozzle and on the bottom of the pocket near the pouring orifice.
  • the steel is then poured into the ladle, and a crust of variable thickness is formed at the bottom of the ladle, especially above the layer of sand in the nozzle.
  • the nozzle is opened, the sand flows and the hydrostatic pressure of the steel in the bag is strong enough to break the crust and cause the flow.
  • this is only true in principle and there are many cases where the crust is too solid for it to be broken by said hydrostatic pressure.
  • one of the aims of the present invention is to provide a nozzle which makes it possible to avoid inadvertent blockages of the nozzle and the drawbacks which result therefrom, whether in terms of the steel grade with a possible derating of this and the loss of time and productivity of the entire installation.
  • Another object of the present invention is to provide an assisted opening system for implementing the nozzle of the above type.
  • Another object of the present invention is to provide an assisted opening method using the above nozzle.
  • a pouring nozzle of refractory material for a metal transport pocket comprising an upper part and a lower part, this lower part being made of a material impermeable to gas, characterized by means for supplying gas to said upper part only.
  • One of the roles of the nozzle according to the present invention is to allow the arrival of gas in the vicinity of the crust of sand and metal at the bottom of the pocket and thus to develop a force which is capable of breaking this crust.
  • one of the preferred modes of the latter consists of a nozzle formed of a porous permeable part. gas, forming the upper part of the nozzle, while the rest is made of a gas-impermeable material.
  • the porous materials are chosen from the group consisting of alumina, magnesia, alumina-chromium mixture, zirconia, zircon, silica and any refractory with a carbonaceous nitride, ceramic and chemical binder. It goes without saying that the porous material is necessarily refractory and must be able to withstand the temperature of the liquid metal to be transported.
  • the nozzle can also be produced in such a form or be produced in several pieces which are cemented together by means of a binder adapted to this type of refractory.
  • the nozzle can also be made of refractory elements linked together by means of a ceramic carbon or chemical binder. This applies to both porous refractory pieces and to solid refractory pieces.
  • the means of bringing gas to said upper part can be a channel of a special shape to ensure a good distribution of the supply of gas to the porous part, and to avoid as much as possible a pressure drop during the passage through the latter.
  • the means of supplying a gas to the upper part can also be a jacket surrounding the nozzle or even pipes.
  • the permeability of the nozzle can also be achieved by means of at least one preferably a plurality of channels, the upper orifice of which opens onto the upper surface of said nozzle.
  • a plurality of channels or tubing systems will be chosen.
  • These channels or of these tubes is chosen from the group consisting of cylinders, cylinder portions and any usual form of tubes.
  • the permeability of the nozzle can be ensured simultaneously by the use of a porous material and by networks of a network of channels in its upper part.
  • the average diameter of its pores is preferably less than 100 micrometers, advantageously from 1 to 10 micrometers (a significant figure); when using tubes, their diameter is preferably less than 1 mm.
  • porous nozzles It had already been proposed to use porous nozzles, but in this case they were totally porous nozzles whose purpose was to ensure the injection of a weak stream of argon during casting, to avoid the accumulation of alumina in the tap hole.
  • EP-A-0059805 describes a nozzle of this type. A gas stream is injected into the sprue to prevent the formation of deposits.
  • the nozzle is only permeable in its upper part. It is not possible to use a completely permeable nozzle, since such a nozzle promotes cooling and solidification in the taphole with an even worse opening than normal. This is why the lower part, preferably at least the lower half, of the nozzle must be made of gas-impermeable material.
  • Another object of the present invention is an assisted opening casting system and a pocket equipped with this system comprising at least one nozzle, a nozzle fixing system and a system of drawers for opening the nozzle.
  • a casting system is shown in Figure 2.
  • the elements of the nozzle are referenced as in the previous drawing: the bottom of the pocket 6, a system of drawers comprising a fixed part 7 in the use which is described, a mobile part 8, with a hole for casting 9 and a part guiding the jet 10.
  • the hole 9 is put by translation of the movable part 8 opposite the opening 1, causing the flow of filling sand of the opening then the breaking of the crust of steel and sand.
  • an inert gas such as argon, rare gases, non-reactive mixtures with respect to - screw of the metal to be transported (cf. CLU technique) in the permeable part of the nozzle at a pressure sufficient to break the crust. It is possible to increase the pressure until the detection on the surface of the molten metal bath of release of inert gas or a decrease in the back pressure in the nozzle.
  • This injection of an inert gas has the advantage of stirring the metal bath in the vicinity of the taphole and therefore of heating it, which facilitates pouring.
  • the pressure of the inert gas is determined case by case, it can however be indicated that a pressure higher than twice the hydrostatic pressure of the metal bath is often necessary.
  • the differential pressure relative to the hydrostatic pressure of the metal bath, necessary is approximately equal to from one to five times said hydrostatic pressure or relative to atmospheric pressure 2 to 6 times said hydrostatic pressure.

Description

La présente invention a pour objet une busette de coulée à ouverture assistée, elle porte également sur des poches de coulée équipées d'une telle busette et sur le moyen d'utilisation d'une telle busette.The present invention relates to a casting nozzle with assisted opening, it also relates to ladles fitted with such a nozzle and to the means of using such a nozzle.

Dans l'industrie de la métallurgie en voie ignée on transporte le métal fondu soit pour le traiter métallurgiquement comme par exemple dans la coulée continue, soit pour le conduire vers des opérations d'affinage, soit pour toute autre raison, au moyen de récipients appelés poches. Le transfert du métal liquide de la poche vers l'outil où le métal doit être traité, se fait soit par déversement, soit au moyen de trous de coulée le plus souvent équipés de busette. L'ouverture des trous de coulée est un problème général, souvent difficile à résoudre, surtout lorsque le métal est un métal ou un alliage à haut point de fusion, tel que le fer et les différents aciers dont le point de fusion est voisin de celui du fer.In the metallurgy industry in the igneous way, the molten metal is transported either to treat it metallurgically as for example in continuous casting, or to lead it to refining operations, or for any other reason, by means of containers called pockets. The transfer of liquid metal from the pocket to the tool where the metal is to be treated, is done either by pouring, or by means of tap holes most often fitted with a nozzle. The opening of tap holes is a general problem, often difficult to solve, especially when the metal is a metal or an alloy with a high melting point, such as iron and various steels whose melting point is close to that iron.

Le problème est d'autant plus aigu lorsque l'opération réalisée sur le métal liquide est une opération de métallurgie physique, c'est-a-dire dans laquelle il n'est plus possible de faire des additions pour remettre le métal ou l'alliage à la nuance voulue.The problem is all the more acute when the operation carried out on the liquid metal is a physical metallurgy operation, that is to say in which it is no longer possible to make additions to return the metal or the alloy in the desired shade.

En effet, lors de l'ouverture du trou de coulée, on est souvent contraint d'utiliser la technique de lances à oxygène qui permettent de fondre la croûte superficielle au moyen de la chaleur dégagée par la combustion de la lance au contact de l'oxygène. Cette injection d'oxygène peut modifier la composition de l'alliage ou du métal, elle est particulièrement gênante dans le cas de l'acier destiné à une coulée continue.Indeed, during the opening of the tap hole, one is often forced to use the technique of oxygen lances which make it possible to melt the surface crust by means of the heat released by the combustion of the lance in contact with the oxygen. This oxygen injection can modify the composition of the alloy or of the metal, it is particularly troublesome in the case of steel intended for continuous casting.

Le problème qui vient d'être exposé est particulièrement important dans le cas des poches de coulée utilisées pour les systèmes de coulée continue dans la sidérurgie. L'invention qui sera exposée par la suite est également dirigée particulièrement vers la résolution de ce problème. C'est pour cette raison que dans la suite de la description, on ne se réfèrera plus qu'au problème des poches de coulée continue dans la sidérurgie. Cette application servira de paradigme à toutes les autres applications.The problem which has just been exposed is particularly important in the case of ladles used for continuous casting systems in the steel industry. The invention which will be explained below is also directed particularly towards solving this problem. It is for this reason that in the following description, we will only refer to the problem of continuous casting ladles in the steel industry. This application will serve as a paradigm for all other applications.

Selon la technique la plus généralement utilisée, les poches de coulée continue sont équipées d'une busette disposée au fond de la poche et maintenues par un système réfractaire. Cette busette présente en son centre une ouverture cylindrique par ou s'écoule le métal fondu. Le système de fermeture de cette ouverture est en général du type à tiroir.According to the most generally used technique, the continuous casting bags are equipped with a nozzle arranged at the bottom of the bag and held by a refractory system. This nozzle has in its center a cylindrical opening through which the molten metal flows. The closure system of this opening is generally of the drawer type.

En fonctionnement le tiroir étant fermé, on remplit l'ouverture de la busette par un sable en général formé de matière réfractaire, et on laisse déborder ce sable dans la partie supérieure de la busette et sur le fond de la poche à proximité de l'orifice de coulée. L'acier est alors versé dans la poche, et une croûte d'épaisseur variable se forme au fond de la poche de coulée et notamment au dessus de la couche de sable de la busette. Au moment de vider la poche, on ouvre le trou de coulée de la busette, le sable s'écoule et la pression hydrostatique de l'acier se trouvant dans la poche est suffisamment forte pour briser la croûte et provoquer l'écoulement. Toutefois, ceci n'est vrai qu'en principe et nombreux sont les cas ou la croûte est trop solide pour qu'elle soit brisée par ladite pression hydrostatique.In operation, the drawer being closed, the opening of the nozzle is filled with a sand generally formed of refractory material, and this sand is allowed to overflow in the upper part of the nozzle and on the bottom of the pocket near the pouring orifice. The steel is then poured into the ladle, and a crust of variable thickness is formed at the bottom of the ladle, especially above the layer of sand in the nozzle. When emptying the bag, the nozzle is opened, the sand flows and the hydrostatic pressure of the steel in the bag is strong enough to break the crust and cause the flow. However, this is only true in principle and there are many cases where the crust is too solid for it to be broken by said hydrostatic pressure.

Il faut alors déboucher comme cela a été expliqué ci-dessus, au moyen de lances à oxygène avec le risque de perdre la production de la coulée correspondante continue.It is then necessary to open as has been explained above, by means of oxygen lances with the risk of losing the production of the corresponding continuous casting.

C'est pourquoi un des buts de la présente invention est de fournir une busette qui permet d'éviter les bouchages intempestifs de la busette et les inconvénients qui en découlent, que ce soit au niveau de la nuance d'acier avec un possible déclassement de celui-ci et de la perte de temps et de productivité de l'ensemble de l'installation.This is why one of the aims of the present invention is to provide a nozzle which makes it possible to avoid inadvertent blockages of the nozzle and the drawbacks which result therefrom, whether in terms of the steel grade with a possible derating of this and the loss of time and productivity of the entire installation.

Un autre but de la présente invention est de fournir un système d'ouverture assistée pour mettre en oeuvre la busette du type ci-dessus.Another object of the present invention is to provide an assisted opening system for implementing the nozzle of the above type.

Enfin, un autre but de la présente invention est de fournir un procédé d'ouverture assistée mettant en oeuvre la busette ci-dessus.Finally, another object of the present invention is to provide an assisted opening method using the above nozzle.

Ces buts et d'autres qui apparaîtront par la suite sont atteints au moyen d'une busette de coulée en matériau réfractaire pour poche de transport de métal, comportant une partie supérieure et une partie inférieure, cette partie inférieure étant réalisée en un matériau imperméable au gaz, caractérisée par un moyen pour amener un gaz à la dite partie supérieure uniquement.These aims and others which will appear subsequently are achieved by means of a pouring nozzle of refractory material for a metal transport pocket, comprising an upper part and a lower part, this lower part being made of a material impermeable to gas, characterized by means for supplying gas to said upper part only.

Ainsi, selon la présente invention, il a été démontré qu'il était possible de rompre la croûte formée lors du transport de l'acier en injectant un gaz inerte vis-à-vis du métal à une pression nettemment supérieure à celle de la pression hydrostatique du métal liquide.Thus, according to the present invention, it has been demonstrated that it was possible to break the crust formed during the transport of steel by injecting an inert gas with respect to the metal at a pressure significantly higher than that of the pressure. hydrostatic liquid metal.

Un des rôles de la busette selon la présente invention est de permettre l'arrivée du gaz au voisinage de la croûte de sable et de métal du fond de la poche et ainsi de développer une force qui soit susceptible de briser cette croûte.One of the roles of the nozzle according to the present invention is to allow the arrival of gas in the vicinity of the crust of sand and metal at the bottom of the pocket and thus to develop a force which is capable of breaking this crust.

Quoique l'on ne puisse exclure des moyens de faire arriver le gaz par un simple canal d'arrivée du gaz inerte à la surface supérieure de la busette, un des modes préférés de cette dernière consiste en une busette formée d'une partie poreuse perméable au gaz, formant la partie supérieure de la busette, cependant que le reste est constitué par un matériau imperméable au gaz.Although one cannot exclude means of bringing the gas through a simple inert gas inlet channel to the upper surface of the nozzle, one of the preferred modes of the latter consists of a nozzle formed of a porous permeable part. gas, forming the upper part of the nozzle, while the rest is made of a gas-impermeable material.

De préférence, les matériaux poreux sont choisis dans le groupe constitué par l'alumine, la magnésie, le mélange alumine-chrome, la zircone, le zircon, la silice et tout réfractaire à liant carboné nitrure, céramique et chimique. Il va de soi que le matériau poreux est nécessairement réfractaire et doit pouvoir supporter la température du métal liquide à transporter.Preferably, the porous materials are chosen from the group consisting of alumina, magnesia, alumina-chromium mixture, zirconia, zircon, silica and any refractory with a carbonaceous nitride, ceramic and chemical binder. It goes without saying that the porous material is necessarily refractory and must be able to withstand the temperature of the liquid metal to be transported.

La manière de réaliser cette busette composite fait appel à des techniques connues, comme par exemple un frittage par pression.The way of making this composite nozzle calls upon known techniques, such as for example pressure sintering.

La busette peut être également réalisée d'un tel tenant ou être réalisée en plusieurs pièces que l'on cimente entre elles au moyen de liant adapté à ce type de réfractaire.The nozzle can also be produced in such a form or be produced in several pieces which are cemented together by means of a binder adapted to this type of refractory.

La busette peut également être réalisée en éléments de réfractaire liés entre eux au moyen d'un liant céramique de carbone ou chimique. Cela vaut aussi bien pour les pièces de réfractaire poreux que pour les pièces de réfractaire plein.The nozzle can also be made of refractory elements linked together by means of a ceramic carbon or chemical binder. This applies to both porous refractory pieces and to solid refractory pieces.

Les moyens d'amener du gaz à ladite partie supérieure peut être un canal d'une forme spéciale pour assurer une bonne répartition de l'amenée du gaz à la partie poreuse, et pour éviter au maximum une perte de charge lors du passage à travers cette dernière.The means of bringing gas to said upper part can be a channel of a special shape to ensure a good distribution of the supply of gas to the porous part, and to avoid as much as possible a pressure drop during the passage through the latter.

Le moyen d'amener un gaz à la partie supérieure peut également être une chemise entourant la busette ou bien encore des tubulures.The means of supplying a gas to the upper part can also be a jacket surrounding the nozzle or even pipes.

La perméabilité de la busette peut être également réalisée au moyen d'au moins un canal de préférence une pluralité, dont l'orifice supérieure débouche à la surface supérieure de ladite busette. De préférence, on choisira une pluralité de canaux ou des systèmes formant tubulures.The permeability of the nozzle can also be achieved by means of at least one preferably a plurality of channels, the upper orifice of which opens onto the upper surface of said nozzle. Preferably, a plurality of channels or tubing systems will be chosen.

La forme de ces canaux ou de ces tubulures est choisie dans le groupe constitué par des cylindres, des portions de cylindre et toute forme usuelle des tubulures.The shape of these channels or of these tubes is chosen from the group consisting of cylinders, cylinder portions and any usual form of tubes.

Enfin, la perméabilité de la busette peut être assurée simultanément par l'emploi d'un matériau poreux et par des réseaux d'un réseau de canaux dans sa partie supérieure.Finally, the permeability of the nozzle can be ensured simultaneously by the use of a porous material and by networks of a network of channels in its upper part.

Lorqu'un matériau poreux est choisi, le diamètre moyen de ses pores est de préférence inférieur à 100 micromètres avantageusement de 1 à 10 micromètres (un chiffre significatif); lorsqu'on utilise des tubulures, leur diamètre est de préférence inférieur à 1 mm.When a porous material is chosen, the average diameter of its pores is preferably less than 100 micrometers, advantageously from 1 to 10 micrometers (a significant figure); when using tubes, their diameter is preferably less than 1 mm.

Il avait déjà été proposé d'utiliser des busettes poreuses, mais il s'agissait dans ce cas de busettes totalement poreuses dont le but était d'assurer l'injection d'un courant faible d'argon pendant la coulée, pour éviter l'accumulation de l'alumine dans le trou de coulée.It had already been proposed to use porous nozzles, but in this case they were totally porous nozzles whose purpose was to ensure the injection of a weak stream of argon during casting, to avoid the accumulation of alumina in the tap hole.

Le document EP-A-0059805 décrit une busette de ce type. Un courant de gaz est injecté dans le canal de coulée afin d'empêcher la formation de dépôts.The document EP-A-0059805 describes a nozzle of this type. A gas stream is injected into the sprue to prevent the formation of deposits.

Contrairement à cet état de la technique selon la présente invention, la busette n'est perméable que dans sa partie supérieure. Il n'est pas possible d'utiliser une busette complètement perméable, car une telle busette favorise le refroidissement et la prise en masse dans le trou de coulée avec comme corollaire une ouverture encore pire que la normale. C'est pourquoi, la partie inférieure, de préférence au moins la moitié inférieure, de la busette doit être en matériau imperméable au gaz.Unlike this state of the art according to the present invention, the nozzle is only permeable in its upper part. It is not possible to use a completely permeable nozzle, since such a nozzle promotes cooling and solidification in the taphole with an even worse opening than normal. This is why the lower part, preferably at least the lower half, of the nozzle must be made of gas-impermeable material.

Des exemples de réalisation de busette sont représentés à la figure 1.

  • La figure 1a représente une busette avec un trou de coulée axiale référencée 1, une partie perméable au matériau poreux référencée 2, des moyens d'amenée de gaz 3a et 3b.
  • La figure 1b représente une busette du même type que précédemment avec les mêmes références ou les moyens d'amenée du gaz 3 sont constitués par une chemise entourant la busette. La partie imperméable étant référencée 4.
  • La figure 1c représente également une busette selon l'invention, dans laquelle il n'y a pas de partie poreuse 2, mais une partie imperméable, rendue perméable par un système d'amenée des gaz 3 qui se prolonge jusqu'à la surface supérieure de la busette. Ces moyens d'amenée de gaz étant bien entendu réalisés en matériau réfractaires.
  • La figure 1d représente une busette réalisée en deux parties: une partie poreuse référencée 2 comme dans les dessins précédents et une partie non poreuse référencée 4. Les deux parties étant cimentées entre elles par un liant réfractaire 40. Les moyens d'amenée du gaz ne sont pas représentés sur cette figure.
Examples of nozzle construction are shown in Figure 1.
  • FIG. 1a represents a nozzle with an axial pouring hole referenced 1, a permeable part to the porous material referenced 2, gas supply means 3a and 3b.
  • Figure 1b shows a nozzle of the same type as above with the same references or the gas supply means 3 are constituted by a jacket surrounding the nozzle. The waterproof part being referenced 4.
  • FIG. 1c also represents a nozzle according to the invention, in which there is no porous part 2, but an impermeable part, made permeable by a gas supply system 3 which extends to the upper surface of the nozzle. These gas supply means being of course made of refractory material.
  • FIG. 1d represents a nozzle produced in two parts: a porous part referenced 2 as in the previous drawings and a non-porous part referenced 4. The two parts being cemented together by a refractory binder 40. The means for supplying the gas do not are not shown in this figure.

Un autre but de la présente invention est un système de coulée à ouverture assistée et une poche équipée de ce système comportant au moins une busette, un système de fixation de la busette et un système de tiroirs pour l'ouverture de la busette. Un tel système de coulée est représenté à la figure 2.Another object of the present invention is an assisted opening casting system and a pocket equipped with this system comprising at least one nozzle, a nozzle fixing system and a system of drawers for opening the nozzle. Such a casting system is shown in Figure 2.

Dans cette figure, les éléments de la busette sont référencés comme dans le dessin précédent: le fond de la poche 6, un système à tiroirs comportant une partie fixe 7 dans l'utilisation qui est décrite, une partie mobile 8, avec un trou de coulée 9 et une pièce guidant le jet 10. Dans ce système d'ouverture à tiroirs en marche normale, le trou 9 est mis par translation de la partie mobile 8 en face de l'ouverture 1, provoquant l'écoulement du sable de remplissage de l'ouverture puis la rupture de la croûte d'acier et de sable.In this figure, the elements of the nozzle are referenced as in the previous drawing: the bottom of the pocket 6, a system of drawers comprising a fixed part 7 in the use which is described, a mobile part 8, with a hole for casting 9 and a part guiding the jet 10. In this opening system with drawers in normal operation, the hole 9 is put by translation of the movable part 8 opposite the opening 1, causing the flow of filling sand of the opening then the breaking of the crust of steel and sand.

Selon l'invention, avant de mettre le trou 9 en face de l'ouverture 1, on injecte par l'intermédiaire des moyens 3, un gaz inerte, tel que l'argon, les gaz rares, des mélanges non réactifs vis-à-vis du métal à transporter (cf. technique CLU) dans la partie perméable de la busette à une pression suffisante pour rompre le croûte. Il est possible de faire monter la pression jusqu'au moment où l'on détecte à la surface du bain de métal fondu un dégagement de gaz inerte ou une diminution de la contre-pression dans la busette.According to the invention, before putting the hole 9 in front of the opening 1, an inert gas, such as argon, rare gases, non-reactive mixtures with respect to - screw of the metal to be transported (cf. CLU technique) in the permeable part of the nozzle at a pressure sufficient to break the crust. It is possible to increase the pressure until the detection on the surface of the molten metal bath of release of inert gas or a decrease in the back pressure in the nozzle.

Cette injection d'un gaz inerte présente l'avantage de brasser le bain métallique au voisinage du trou de coulée et donc de le réchauffer, ce qui facilite la coulée. La pression du gaz inerte est déterminée cas par cas, on peut toutefois indiquer qu'une pression supérieure à deux fois la pression hydrostatique du bain métallique est souvent nécessaire. En général toutefois, la pression différentielle (par rapport à la pression hydrostatique du bain de métal), nécessaire est environ égale à de une à cinq fois ladite pression hydrostatique soit par rapport à la pression atmosphérique 2 à 6 fois ladite pression hydrostatique.This injection of an inert gas has the advantage of stirring the metal bath in the vicinity of the taphole and therefore of heating it, which facilitates pouring. The pressure of the inert gas is determined case by case, it can however be indicated that a pressure higher than twice the hydrostatic pressure of the metal bath is often necessary. In general, however, the differential pressure (relative to the hydrostatic pressure of the metal bath), necessary is approximately equal to from one to five times said hydrostatic pressure or relative to atmospheric pressure 2 to 6 times said hydrostatic pressure.

Claims (9)

1. A nozzle made of refractory material for a ladle for conveying metal, comprising an upper part and a lower part, this lower part being made of a material which is impermeable to gas, characterised by a means for admitting a gas at said upper part only.
2. A nozzle according to claim 1, characterised in that said upper part is composed of a porous material.
3. A nozzle according to claim 2, characterised in that this permeable material is selected from the group comprising alumina, magnesia, an alumina-chromium mixture, zirconia, zircon, silica and any refractory material with a nitride, ceramic and chemical carbonaceous binder.
4. A nozzle according to claim 1, characterised in that said upper part is rendered permeable by at least one conduit, the upper orifice of which opens on to the upper surface of said nozzle.
5. A nozzle according to claim 4, characterised in that the conduit is of a form selected from the group comprising cylinders, cylindrical portions and any other usual form of piping.
6. A casting system with assisted opening, characterised in that it comprises at least one nozzle according to claims 1 to 5, a securing system for the nozzle and a system of slide members for opening the nozzle.
7. A ladle for conveying liquid metal, characterised in that it is provided with a system according to claim 6.
8. A method for the assisted opening of a nozzle according to claims 1 to 6, characterised in that, before the opening system is operated, an inert gas is injected through the upper part of the nozzle at a pressure which is higher than the hydrostatic pressure of the molten metal until the occurrence of bubbles on the surface of said molten metal or a drop in the residual pressure in the porous part of the nozzle is detected.
9. A method according to claim 8, characterised in that the pressure of the inert gas is between two and six times the hydrostatic pressure of the metallic bath.
EP89400411A 1988-02-26 1989-02-14 Nozzle for assisting orifice,device incorporated therein and method for method for carrying out Expired - Lifetime EP0332483B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8802407A FR2627715B1 (en) 1988-02-26 1988-02-26 CASTING NOZZLE FOR ASSISTED OPENING, DEVICE INCORPORATING THE SAME, AND IMPLEMENTATION METHOD
FR8802407 1988-02-26

Publications (2)

Publication Number Publication Date
EP0332483A1 EP0332483A1 (en) 1989-09-13
EP0332483B1 true EP0332483B1 (en) 1992-01-22

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP89400411A Expired - Lifetime EP0332483B1 (en) 1988-02-26 1989-02-14 Nozzle for assisting orifice,device incorporated therein and method for method for carrying out

Country Status (6)

Country Link
US (1) US5016788A (en)
EP (1) EP0332483B1 (en)
JP (1) JPH0237959A (en)
DE (1) DE68900736D1 (en)
ES (1) ES2028448T3 (en)
FR (1) FR2627715B1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3934601C1 (en) * 1989-10-17 1990-10-04 Didier-Werke Ag, 6200 Wiesbaden, De
DD301654A5 (en) * 1990-08-24 1993-05-19 Eko Stahl Ag FREE SHIPPING FOR METALLURGICAL GEFAESSES WITH FLOOR CLOSURE
US5723055A (en) * 1995-10-10 1998-03-03 Vesuvius Crucible Company Nozzle assembly having inert gas distributor
DE102014114301A1 (en) 2014-10-01 2016-04-07 Hermann Rauen GmbH & Co vorm. Steinhandel Rauen Apparatus and method for opening a spout channel of metallurgical vessels

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3651825A (en) * 1969-10-24 1972-03-28 Francis P Sury Stopper plug valve for hot metal ladles
US3838798A (en) * 1971-01-21 1974-10-01 Leco Corp Porous tundish nozzle
CA972455A (en) * 1971-11-08 1975-08-05 Compagnie Generale De Geophysique Dispositif d'exploitation pour l'obtention d'informations sismiques tridimensionnelles
IT974028B (en) * 1971-12-29 1974-06-20 Stoecker U Kunz Gmbh IMPROVEMENT IN THE SPOUT ARRANGEMENTS FOR CONTAINERS CONTAINING MELTED METALS
DE2731113A1 (en) * 1977-07-09 1979-01-18 Didier Werke Ag POURING MOLD AND METHOD FOR THE PRODUCTION THEREOF
GB2093169B (en) * 1981-02-12 1984-11-21 Flogates Ltd Metal pouring apparatus and method
EP0059805B1 (en) * 1981-03-11 1985-02-13 Junichi Ato Porous nozzle for molten metal vessel
US4756452A (en) * 1986-11-13 1988-07-12 Shinagawa Refractories Co., Ltd. Molten metal pouring nozzle
US4836508A (en) * 1988-05-03 1989-06-06 Vesuvius Crucible Company Ladle shroud with co-pressed gas permeable ring

Also Published As

Publication number Publication date
FR2627715B1 (en) 1991-10-11
US5016788A (en) 1991-05-21
EP0332483A1 (en) 1989-09-13
JPH0237959A (en) 1990-02-07
FR2627715A1 (en) 1989-09-01
DE68900736D1 (en) 1992-03-05
ES2028448T3 (en) 1992-07-01

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