JPS59133312A - Refractory element with tuyere and consumption prevention for refractories - Google Patents

Abstract

1. A refractory tuyere holding element for a vessel for treating a liquid metal, of the type which comprises a refractory mass surrounding an injection tuyere, said refractory mass being provided with passages connected to a source of pressurized auxiliary protection fluid which opens into the liquid metal bath, characterized in that it consists of a plurality of subelements made of compact refractory material (2, 3, 4, 5) separated by narrow slits performing the role of said passages and connected to a source (16) of liquid or gaseous carbonaceous agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refractory element having a wall as a container for processing liquid metal, the element containing a refractory odor surrounding the pouring wall, the refractory odor being removed under pressure. and a passage in communication with a source of auxiliary fluid injected into the liquid metal bath.

In practice, it is known that for protected oxygen linings, the determining factor in the service life of the converter bottom is the wear of the surrounding refractory and not the wear of the tuyeres.

The converter furnace is protected against thermal effects and corrosion while using an element of the aforementioned type containing a cooling auxiliary gas fluid that, on the one hand, reduces the temperature in the region near the nozzle and, on the other hand, forms a gas cushion that protects the blowing surface. Attempts have already been made to protect the bottom.

Such elements are described, for example, in French Patent No. 1.
Known from 3/17, No. 01.4. In the element described in the French patent, the passages are preferably made of a refractory made porous for this purpose, or alternatively achieved by providing artificially fine grooves in a dense refractory. be done. From a technical point of view, the devices leave passages for gaseous auxiliary fluids (because the passage of the fluid is blocked by large resistances), as well as subtle manufacturing methods (especially the creation of artificial narrow grooves). It has two drawbacks. Moreover, experience has shown that the results obtained are not entirely satisfactory and that the field of application is limited.

The present invention overcomes the above-mentioned drawbacks, is easy to manufacture, and enables effective protection of the refractory surrounding the tuyere of a converter.
The purpose is to provide fireproof elements.

This purpose, according to the invention, is to provide a liquid or gaseous solution, in which the refractory elements are separated by narrow gaps serving as the passages, and which can provide a carbon protection by impregnating the upper layer of the refractory elements. This is achieved due to the fact that it comprises an assembly of refractory elements in communication with a carbon-containing agent.

Advantageously, the collection of sub-elements is surrounded by a steel cylinder and maintained at a distance from the bottom plate so as to form a space for the distribution of the carbon-containing reagent. The agent is preferably a hydrocarbon, advantageously a liquid fuel.

The invention likewise relates to a method for preventing wear of a metallurgical vessel bottom refractory, which comprises an element with the aforementioned linings in the head of the device. According to the method of the invention, carbonization of a liquid or gaseous carbon-containing agent, preferably a liquid fuel, which is liable to provide a carbon protector, is carried out by impregnation of the upper layer of the refractory element across a narrow groove across the refractory odor. Hydrogen is injected.

As will be appreciated, one of the defining features of the present invention is the provision of a fuel diffusion surface in the vicinity of the nozzle of the tuyere through which scouring oxygen is injected, for impregnating the surface and upper layer of the refractory with carbon. form.

The carbon has the dual role of chemical protection against iron oxides (such as FeO) that attack the refractory and creating a layer with some degree of elasticity, and thermodynamic protection.

The invention will be better understood by the following two preferred embodiments, which will be described with reference to the accompanying drawings.

FIG. 1 shows a refractory element 1 whose shape approximates a truncated pyramid with a rectangular base, narrowing slightly upwards. By way of example only, the element has a base of 150 x 110 mm2 in the upper part for a height of 27511 m;
Obtain a surface of 142 x 105 mm2 in the upper part.

Element 1 has four juxtaposed subelements 2.3
．． 4.5 and is formed from a plate made of a prior art dense refractory material, such as magnesia. The plate is assembled with a metal jacket 6 having a thickness of 1.5 mm. A gap 17 is maintained between said adjacent plates by means of calibrated linear crosspieces 7.

The steel plate 6 is welded to a bottom plate 8 with a thickness of 3 fins, so that the refractory plate 2.3.4.5 has, for example, a space 1 of 2 fins in thickness.
They are supported separately by pillars 9 whose height is calibrated to leave zero.

The oxygen blowing tuyere is located in a cylindrical cutout 12 with a diameter of 22 provided between the two center plates 3 and 4.

In FIG. 1, a hollow part 12 is shown comprising a central tube 11 for oxygen injection connected to an oxygen source 14 and an outer tube 13 providing an annular passage for fuel supplied with fuel by a fuel source 15. Double tuyeres are shown.

The lower space 10 is fed across the bottom plate 8 by a second fuel source 16 . Fuel is distributed into this space under a pressure of 4 to 5 bar, which fills the slot 17 and is ejected into the metal at a rate close to zero. In this way, diffusion of the fuel is ensured.

In the embodiment shown in FIG. 2, there is an assembly play between the tube 11 and the cutout 12 in which it is mounted directly, which play is limited to the annular space of the double tuyere. play the role of Therefore, in this annular space,
The fuel distribution space 10 provides direct fuel supply, thereby eliminating the need for a separate source 15.

The projection 18 of the tube 11 can maintain a sufficient radial spacing (for example l mm) between the tube 11 and the cutout 12.

If the lining is not protected, sufficient bonded articles may be packed into the assembly play.

The plates 2.3.4.5 may be bare or have surfaces delimiting the slots 17, for example, in order to facilitate fuel circulation or to prevent fuel penetration into the boundaries of the element. At least a portion of the top is coated. Furthermore, the spacing crosspieces are not completely essential, so that passage gaps 17 can be formed between the fireproof plates simply by juxtaposing them.

As already mentioned, the present invention is not limited in any way by the use of fuel, but any other hydrocarbon, preferably in liquid form, which facilitates impregnation of the refractory top layer to provide a carbon protective layer thereto. You can also use

Further, the tuyeres do not necessarily need to be installed between two fireproof plates, but can be installed in the center of one plate (of course, they can also be installed in a hollowed out part).

In addition, the invention has general application to any treatment of molten metal in a metallurgical vessel equipped with a nozzle for blowing treatment agents below the surface of the bath.

The invention applies in particular to steelmaking converters with oxygen blowing from the bottom, optionally in combination with blowing from the top by means of projecting lances discharging onto the bath.

[Brief explanation of the drawing]

FIG. 1 is a vertical view, not to scale, of the lower part of the first embodiment of the invention, and FIG.
FIG. 3 is a horizontal cross-sectional view taken along the line ■-■ of FIG. 2; (Reference number) 1. Fireproof element, 2.3.4.5. Sub-element, 6. Steel plate, 7. Crosspiece, 8. Bottom plate, 9. Support column,
10... Space, 11... Central tube, 12... Cylindrical hollowed out part, 13... External tube, 14... Oxygen source, 15.16
...Fuel source, 17. Slit, work 8. Projection of pipe 11,
Applicant
Sidelurgy Française (Iljid) Agent Patent Attorney Seinen Arai! JL-Town Li

Claims (1)

Claims: (1) including a refractory ring surrounding the injection cuff, the refractory ring having a passageway in communication with a source of pressurized protective auxiliary fluid and opening into a bath of liquid metal; 2.3.4.5 A refractory element with tuyere for a processing vessel for liquid metals, said refractory element comprising a certain combination of a plurality of dense refractory subelements 2.3.4.5; A liquid or gas (2) whose elements are separated from each other by slots serving as passages, which slots can provide a carbon protection by impregnating the upper layer of the refractory element.
A refractory element according to claim 1, characterized in that said sub-element is connected to a hydrocarbon source (16). (3) The refractory element according to claim 2, wherein the sub-element is connected to a liquid fuel source. (4) The fireproofing according to any one of claims 1 to 3, characterized in that the wing is provided between two specially formed sub-elements 3.4. element. (5) The refractory element according to any one of claims 1 to 4, wherein the tuyere is a double tuyere. (6) the bottom of the container for processing liquid metals includes a refractory element having tuyeres, within which the tuyeres are surrounded by a dense refractory ring divided with slits;
in a method of preventing depletion of refractories in the bottom of the vessel, injecting a protective auxiliary fluid across the gap and expelled into a liquid bath under pressure, across the refractory odor. A method for preventing wear of refractories as described above, characterized in that a liquid or gaseous carbon-containing agent is injected across the cracks in the refractory element, which can provide a carbon protection by immersing the upper layer of the refractory element. (7) The method according to claim 6, wherein a liquid fuel is injected as the carbon-containing reagent. (8) The method according to claim 6 or 7, which is carried out in a steelmaking converter in which oxygen is blown into the furnace. (9) The method according to claim 8, which is carried out in a steelmaking converter furnace in which oxygen is blown into the furnace through a tuyere and a protruding lance. 00) The method according to claim 6 or 7, which is carried out in a steelmaking converter furnace, in which oxygen is blown in through a protruding lance and a stirring fluid is blown in through tuyeres.