EP1797976A2 - Conical bubble brick - Google Patents

Abstract

The rinsing cone has an internal rinsing channel with a core (1) that is surrounded by filling (4). The core is formed as separate molded part of the filling, which has a form fit external lining towards the axis. The lining is free of metallic construction units. An independent claim is also included for a method of producing rinsing cone for metallurgical containers.

Description

The present invention relates to a flushing cone having the features of the preamble of claim 1.

Flushing cones are known as interchangeable inserts that allow the introduction of gases into molten metals in a container lined with refractory material. The efficiency of this secondary metallurgical treatment depends directly on the effectiveness of the flushing effect of the flushing cone. Flushing cones are generally subject to high chemical, mechanical and thermo-mechanical wear. This explains why repeated attempts have been made to increase the durability of the purging cone and to improve the rinsing effect.

It results in the fact that today many different Types of flushing cones are known. These purging cones can generally be assigned to two groups, on the one hand one-piece flushing cones, which are manufactured from a refractory material into which flushing channels have been introduced in the longitudinal direction. The flushing channels are then formed by residue-free burning out of plastic strips, nets, foils, etc. during annealing or firing process. A jacket of the flushing cone with sheet metal and attaching a flange for the gas inlet to the bottom plate complete the arrangement and are state of the art.

There are still two-part purging cone, as for example from the European Patent EP 0 424 502 B2 are known. In these Spülkegeln an outer, frusto-conical shaped part of refractory material is provided with an inner bore in which a prefabricated, ceramic molded part sits, which already contains Gasspülkanäle. These rinsing inserts are made on extruders and have a fine ceramic character.

In the case of the two-part flushing cones, the attachment of the inner extruded part is very complicated because this extruded part must not be released from the flushing cone under the influence of the hydrostatic pressure of the melt or of the dynamic pressure during the gas supply. The known two-part purging cone are correspondingly expensive to produce and thus cause undesirable high costs in the production.

Flushing cones are also known, which consist of two nested ceramic truncated cones. By introducing a plurality of metal strips between the two truncated cones, a cavity is formed, through which gas can then be blown into the molten metal.

All scavenging cones described here are used in large quantities, but rinsing failures and leading wear accompany their use in the steel treatment ladle.

From the EP 1,372,888 B1 For example, a flushing plug is known which has an inner porous part and an outer gas-tight part. The two parts are filled together in a mold and also pressed together and fired.

From the German patent DE3433349C2 is a so-called edge flushing known, in which a gas-impermeable core is arranged at a distance in a metal shell. The metal shell in turn is positively embedded with an outer contour in a surrounding material. With these washers, liquid metal penetrates into the gap between the core and the metal shell and causes premature failure. It is therefore generally preferred if the core itself is gas permeable.

The closest prior art is in the Austrian Patent Specification E 28 667 B shown. Here, a gas-permeable core is arranged in an embedding material. Between the core and embedding material, a substantially frusto-conical metal shell is arranged, which has an outer contour. This contour allows a positive retention in an embedding material. Due to the different materials and the associated different thermal expansion occurs in such rinsers to gap formation between the refractory materials and the metal shell. The wear is relatively high.

It is therefore an object of the present invention to provide a flushing cone, which is wear-resistant, in which an inadvertent detachment of the inner gas-conducting area is reliably prevented, which is inexpensive to manufacture and also has a good flushing readiness.

This object is achieved by a flushing cone with the features of claim 1. because the core has internal scavenging passages and is formed as a molded part separately from the filling, which has an outer contour enabling a positive locking in the direction of the axis, which is free of metallic components, the solid ceramic filling can safely secure the likewise ceramic core in both hold in the direction of the axis occurring load directions without liquid metal can penetrate into the transition region between the core and surrounding material.

An outer contour of the core which can be reliably produced even under the conditions of ceramic production results if the contour has at least sections of formations or indentations running transversely to the axis. These can be formed, in particular, as outwardly facing convex areas such as ribs or webs, but also as inwardly pointing constrictions, grooves or other concave areas.

It is advantageous if the outer contour of the core is free of spacers, anchors and the like.

The desired advantages in terms of the ceramic material arise when the core is made of a heavy clay concrete. It is advantageous if the filling is made of a coarse ceramic concrete and has no internal flushing channels.

• Formen einem Kerns aus einem grobkeramischen Beton mit einer Ausformungen oder Einprägungen aufweisenden äußeren Oberfläche und innenliegenden, verbrennbaren Formteilen;
• Brennen des Kerns bei einer Temperatur oberhalb von 1000°C, so dass die Formteile im wesentlichen rückstandsfrei verbrennen;
• Abkühlen des Kerns und Ummanteln des Kerns mit einer Füllung in einer Form;
• Verfestigen der Füllung bei niedriger Temperatur;
• Tempern der Anordnung bei einer Temperatur unter 1000°C; sowie
• Ummanteln der Füllung mit einem Blechmantel

In a method according to the invention for producing a flushing cone for metallurgical containers, the following method steps are provided:

• Forming a core of a heavy clay concrete having an outer surface having embossments or indentations and internal, combustible moldings;
• Burning the core at a temperature above 1000 ° C, so that the moldings burn substantially residue-free;
• Cooling the core and sheathing the core with a filling in a form;
• Solidifying the filling at low temperature;
• Annealing the assembly at a temperature below 1000 ° C; such as
• Cover the filling with a metal jacket

• Figur 1: einen erfindungsgemäßen Spülkegel in einem Querschnitt von der Seite; sowie
• Figur 2: den Spülkegel gemäß Figur 1 in einem Querschnitt senkrecht zur Zeichenebene der Figur 1.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Show it:

• Figure 1: a purging cone according to the invention in a cross section from the side; such as
• FIG. 2 shows the flushing cone according to FIG. 1 in a cross section perpendicular to the drawing plane of FIG. 1.

FIG. 1 shows a flushing cone with a core 1 which extends from a side 2 facing the melt to a side 3 of the flushing cone facing away from the melt. The core 1 is surrounded by a filling 4, which in turn is surrounded by an outer metal jacket 5. The jacket 5 leaves the upper side 2 free, while covering the lower side 3 substantially. Region 6 is provided here with a connecting piece 7. The core 1 further comprises a number of gas channels 8, which extend with a free cross section from the bottom 3 to the top 2 of the core 1. The flushing channels 8 are open to the connection piece 7. At the top 2, the flushing channels 8 emerge freely from the top 2.

The core 1 is provided in this illustration with a trapezoidal or truncated cone-shaped cross section, which tapers from the bottom 3 to the top 2 towards.

Side surfaces 9 are substantially flat, but provided with outwardly facing bulges or webs 10. For better handling, a bracket 11 is arranged on the upper side, which simplifies the installation of the flushing cone. This bracket 11 is welded from sheet metal and with the sheath 5. The Jacket 5 itself consists essentially of a circumferential, rotationally symmetrical metal jacket, which is welded gas-tight in the corner region at reference numeral 12 with bottom plate 6.

FIG. 2 shows a cross section through the flushing cone described so far along the line II-II, that is to say perpendicular to the plane of the drawing of FIG. 1. The same components have the same reference numerals.

The flushing channel 8 is substantially wider in its extent in the drawing plane of Figure 2 as perpendicular thereto, as explained in Figure 1. Further, the core 1 is provided with two plane-parallel outer sides 14, which are perfectly smooth. The outer sides 14 are each perpendicular to the outer sides 9 of Figure 1. The filling 4 surrounds the core 1 also on the outer sides 14 and complements the core 1 to the usual frusto-conical and rotationally symmetrical outer shape.

In the production of the core 1 is first made of a refractory coarse-grained concrete, in which this material is filled into a corresponding shape. The mold cavity is defined on the one hand by the plane-parallel outer walls 14 and on the other hand by the converging outer sides 9, which have the webs 10. Inside the mold cavity are plastic strips, usually embedded in polyethylene, which correspond in shape to the later gas channels 8. The refractory material is then fired at temperatures of more than 1000 ° C, wherein the refractory material solidifies as usual and get the gas channels by residue-free combustion of the inserted plastic strips their free, open and continuous cross-section.

After cooling, the thus fired core 1 is covered with a relatively coarse-grained concrete, which gives the filling 4 and the core 1 to the usual frusto-conical outer shape added. This concrete is preferably made on the basis of alumina with or without spinel. But it is also possible to produce a concrete of magnesium oxide. Furthermore, it is possible to combine concrete on different raw material basis.

The concrete surrounding the core 1 is then tempered, the properties of the core 1 not changing. The core 1 is held by its outer geometric shape with the webs 10 positively within the filling 4 and secured.

Again, after cooling, the filling 4 is provided with the metal jacket 5, the top 2 remains free. At the bottom of the metal jacket is supplemented by the bottom plate 6 and welded to the gas guide the flange 7. In operation, gas is fed into the flange 7 and can then be introduced through the gas channels 8 in the upcoming at the top 2 melt.

Because of the positive connection between the core 1 and the filling 4, it is excluded that the core 1 dissolves within the flushing cone and enters the melt, as may occur in other two-part flushing cones. In addition, the described secure mounting of the core 1 in the filling 4 is ensured by simple design measures in the production, instead of making separate fasteners required. In practice, it has been shown that the flushing cone produced in this way exhibits excellent flushing readiness, ie it is neither subject to undesirably high wear nor clogged or completely fails.

The geometric shape of the core 1 in its embedding in the filling 4 is essential to the operation of the present invention. The advantages of the invention are achieved in that between the core 1 and the filling 4 there is a form-fitting, which secures the core 1 after annealing the filling 4 therein. Instead of the trapezoidal outer shape can the core 1 can also be designed round, rectangular or square. The integrally formed on the core 1 webs 10, of which in the described embodiment, a total of six are provided, can be varied as desired in number and the geometric shape. It can also be provided, instead of the webs 10, which bulge outward into the filling 4, constrictions, grooves or the like in the core 1 mold. Such grooves are then filled when filling with the filling 4 and secure the core as well form-fitting within the filling. 4

In the described manufacturing method, the positive properties of heavy clay concretes are made largely usable. The flushing cone is, apart from its coat, completely free of metal parts, core 1 and 4 filling are made of 100% ceramic, which promotes the desired benefits in terms of wear resistance and flushing readiness.

Claims (8)

Flushing cone for metallurgical containers, comprising a core (1) having an internal flushing channel and a filling (4) surrounding the core (1), wherein the core lies in an axis from a side (3) facing away from the melt to a side facing the melt (Fig. 2), characterized in that the core (1) is formed as a molded part which is manufactured separately from the filling (4) and which has an outer contour enabling a positive connection in the direction of the axis, which is free of metallic components. Flushing cone according to claim 1, characterized in that the contour has at least partially transverse to the axis extending formations or indentations. Flushing cone according to one of the preceding claims, characterized in that the contour of ribs, webs or constrictions is formed. Flushing cone according to one of the preceding claims, characterized in that the contour is free of spacers and anchors. Flushing cone according to one of the preceding claims, characterized in that the core (1) is made of a coarse ceramic concrete. Flushing cone according to one of the preceding claims, characterized in that the filling (4) is made of a coarse ceramic concrete and has no internal flushing channels. Method for producing a flushing cone for metallurgical containers, comprising the following method steps: - Forming a core (1) made of a heavy clay concrete with an outer surface having outer or outer shapes and internal, combustible moldings; - Burning the core (1) at a temperature above 1000 ° C, so that the moldings burn substantially residue-free; - cooling the core (1) and sheathing the core (1) with a filling (4) in a mold; - solidifying the filling (4) at low temperature; - Annealing the arrangement at a temperature below 1000 ° C, as well - wrapping the filling with a metal jacket. A method according to claim 7, characterized in that the annealing is carried out at a temperature between 400 ° C and 600 ° C.

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