EP0159217A1 - Seal between a liquid metal-containing vessel and its cover - Google Patents

Abstract

The subject of the invention is a seal between a vessel, with an inner refractory lining and containing a liquid metal, and a metal cover which also has an inner refractory lining, this device being characterised in that the cover is equipped, at its lower part, with a suspended belt, in the form of angle steel, whose vertical flange surrounds the base of the cover at a suitable distance and whose horizontal flange extends under the cover, creating, with the latter, a space whose volume is predetermined in order to receive a given quantity of plastic refractory paste intended to be squashed between the cover and the said vessel in order to provide the seal. The invention applies especially well to open ladles, for cast iron or steel, and to steel mill moulds equipped with certain types of risers. <IMAGE>

Description

The invention relates to the production of a seal between a container containing a liquid metal, such as a cast iron ladle, a steel ladle, an ingot mold, etc., and its extension.

Thus, in the particular case of the pretreatment of ladle pig iron, before its conversion to steel, the addition of certain reactants in the ladle liquid cast iron and the stirring operation, for example to a blowing of gas through permeable elements at the bottom of the ladle, cause the liquid metal to boil and cause significant slag foaming, which require an additional guard height above the level of the bath.

• - Etincëlles et flammes sortant par le joint, accroissant l'insécurité et déformant la cuirasse de la poche et celle de la rehausse ;
• - Dépôts de métal et de laitier entre le revêtement réfractaire de la poche et celui de la rehausse, rendant beaucoup plus difficile la séparation de la poche et de la rehausse après traitement, et endommagement les réfractaires au niveau du joint.

In cases, which are frequent in practice, where the capacity of the pockets cannot be increased, it is possible to use a removable riser placed on the pocket. This raises the problem of the seal between the pocket and the riser, the main drawbacks of poor sealing between the refractories of the pocket and the refractories of the riser being the following:

• - Sparks and flames coming out through the joint, increasing insecurity and deforming the breastplate of the pocket and that of the enhancer;
• - Deposits of metal and slag between the refractory lining of the pocket and that of the riser, making it much more difficult to separate the pocket and the riser after treatment, and damaging the refractories at the joint.

To seal the seal between the pocket and the enhancer, it is generally sufficient to have around the entire periphery of the upper rim of the pocket a plastic refractory paste, and then the enhancer is placed on the pocket, thereby crushing the plastic paste, intended to form the joint. But in this way, the distribution of the plastic paste is often defective, either insufficient and therefore not ensuring sealing, or is overabundant, overflowing inwardly or outwardly from the pocket, therefore with possible incorporation slag, and less control of the composition thereof, for the internal overflow, and a fouling of the pocket and the enhancement for the external overflow, without counting the corresponding loss of refractory material.

The object of the present invention is to provide a tight seal between the pocket and the enhancer, without encountering the drawbacks mentioned. above, that is to say by carefully controlling the amount of plastic refractory paste distributed over the entire periphery of the pocket.

To this end, the subject of the present invention is a sealing device between a container internally coated with refractories, and containing a liquid metal, such as a pocket or an ingot mold for example, and a metal riser also internally coated with refractories, this device being characterized in that the riser is provided at its lower part with a hanging belt having a section in the form of an angle iron, whose vertical wing surrounds the base of the riser at a suitable distance, and whose horizontal wing s extends under the riser, providing with the latter a space whose volume is predetermined to receive a given quantity of plastic refractory paste adapted to the joint volume to be produced after crushing of said paste by the riser when the latter comes to rest on the container, the horizontal wing of the belt then being placed on the upper edge of the container.

According to a particular characteristic of the invention, the horizontal wing of the angle iron forming a belt has openings ensuring, after crushing of the paste, direct contact between the plastic refractory paste and the upper edge of the container.

According to another particular characteristic of the invention, the extension comprises centering plates fixed on its periphery and guiding its positioning on the container, in order to achieve good centering.

As will be understood, one of the main advantages of applying the device according to the invention is that the quantity of refractory paste is dosed well, once and for all, and that its distribution around the periphery of the joint is regular.

Another advantage is that the sealing is excellent, since it is carried out not only between the riser and the container, but also between the riser and the vertical wing of the angle iron forming a belt.

Another advantage of the invention is that the belt can be provided in advance with the desired quantity of plastic refractory paste, on a repair site, outside the operating site, and that it is then sufficient, when use, to suspend the belt thus prepared for the enhancement, for example by means of chains, and then place on the container the enhancement provided with its belt.

In order to clearly understand the device according to the invention and its operation, an embodiment of a device placed on a steel pocket will be described below, by way of nonlimiting example. fitted with an extension.

• Figure 1 is a vertical section of the lower part of the riser and of the device according to the invention, after introduction of the refractory dough, therefore ready for use, and before crushing of the dough.
• FIG. 2 is a vertical section of the lower part of the extension, of the device according to the invention and of the upper part of the steel pocket, after the installation of the extension and its device on the pocket, therefore after crushing of refractory paste.
• Figure 3 is a vertical section of a variant of the belt of the device according to the invention.

In FIG. 1, representing the base of the riser and the device according to the invention before their installation on the pocket, a distinction is made between the vertical part 1 and the horizontal part 2 of the metal breastplate of the riser, and its interior refractory lining 3.

The device according to the invention comprises a belt exactly matching the shape of the pocket and constituted by an angle iron, which has a vertical wing 4 and a horizontal wing 5, the diameter of the ring forming the vertical wing 4 being slightly greater than the diameter of the vertical part 1 of the riser, and the horizontal wing 5 being located at a well calculated distance from part 2 of the riser.

The belt is suspended from the riser by means of several chains such as 6, fixed at 8 to the wing 4 of the belt, and which can be hooked and unhooked at 7.

During the preparation of the riser, as shown in FIG. 1, the belt, suspended in the low position, serves as a support for the seal of plastic refractory paste 9, which can be a paste used in bulk, or a prefabricated tube, but which occupies a well-defined volume between the belt (4) (5) and the riser (2).

Centering plates such as 10 are regularly fixed on the periphery of the vertical part 1 of the riser, either by welding or by any other means, and serve as a guide for positioning the riser on the pocket, in order to achieve good centering .

FIG. 2 represents the second functional position, when the extension and the device are placed on the upper rim of the pocket.

In this FIG. 2, the upper part of the pocket is seen, comprising an almost vertical breastplate 11, and a circular metallic angle iron having an almost vertical wing 12 and a horizontal wing 13. The pouch is coated internally with a refractory lining 14.

Following the installation of the riser and its device on the upper rim of the pocket, thanks to the guidance of dishes such as 10, the plastic refractory pit is crushed, lengthened as well horizontally at 15 between the riser, the wing 5 of the device, and the upper rim of the pocket, only vertically at 16 between the vertical part 1 of the breastplate of the riser and the vertical wing 4 of the belt of the device.

The initial quantity of paste 9, which has become 15 and 16 after crushing, is adjusted in a precise manner, so as to occupy, after crushing, the entire thickness of the refractories 3 and 14, by a suitable length at 15, and to open up at 16 in the vertical gap between the riser 1 and the belt 4.

FIG. 3 represents a variant of the belt, in which the horizontal wing-5 is perforated by orifices such as 17, which allows the contact between the dough 15 and the upper rim 13 of the bag to be increased, and therefore to further improve sealing. One can also use for wing 5 of the belt a crown made of expanded metal.

It is understood that it is possible, without departing from the scope of the invention, to imagine variants and refinements of details, as well as to envisage the use of equivalent means.

The invention applies especially well to iron pockets, or to steel pockets, when they are open pockets (and not barrel pockets) and it also applies to steelworks ingot molds provided with certain types of weights .

Claims (3)

1.- Sealing device between a container coated internally with refractories and containing a liquid metal, and a metal riser also coated internally with refractories, the sealing being ensured by crushing a plastic refractory paste between the riser and said container, characterized in that the riser is provided at its lower part with a hanging belt, in the form of an angle iron, the vertical wing of which surrounds the base of the riser at a suitable distance, and the horizontal wing of which extends beneath the extension, providing with the latter a space whose volume is predetermined to receive a given quantity of plastic refractory paste adapted to the volume of joint to be produced after crushing of said paste. 2.- sealing device according to claim 1, characterized in that the horizontal wing of the angle iron forming a belt has openings ensuring, after crushing of the plastic refractory paste, direct contact between the latter and the upper edge of the container. 3. A sealing device according to any one of claims 1 and 2, characterized in that the extension comprises centering plates fixed on its periphery and guiding its positioning on the container, in order to achieve good centering.

Images