EP0221250B1 - Injector installation for metallurgical vessels - Google Patents

Abstract

1. Injection device for introducing gases into metallurgical vessels which is replaceably inserted in the refractory vessel lining and comprises a refractory moulded body with gas passages extending from an external gas chamber to the outlet side which together with the gas chamber is surrounded by a sheet metal shell, characterised in that the gas passages (18) are constructed as nozzles with constantly reducing cross-section in the direction from the external gas chamber (11) to the outlet side in such a manner that the drop in velocity which is to be expected of the gas flow along the gas passages (18) is compensated for by the reduction in the cross-section.

Description

The invention relates to an injection device for introducing gases into metallurgical vessels, which is interchangeably inserted in the refractory vessel lining and consists of a refractory molded body with gas passages running from an outside gas chamber to the outlet side, which including the gas chamber is surrounded by a sheet metal jacket.

In such a device known from DE-GM 80 28 296.8 in the form of a refractory body with little open, i.e. gas-permeable pores, the gas is conducted through channels which lead radially from a gas collecting space to the gas outlet side of the body. They are provided between separating surfaces of the molded body which is divided longitudinally or crosswise several times and are formed, inter alia, by grooves arranged in the surfaces and opposing surface sections. Here, the channels with the same cross-section open, similar to continuous stone pores, without a targeted outlet formation on the outlet side of the refractory body, so that the velocity loss of the flowing gas present in the constant cross-section of the channels must be compensated for by a relatively high pressure. On the other hand, the position of the individual channel cross sections hardly promotes the mixing of air and melt in the vessel. Furthermore, the production and assembly of the many parts of the body to form the whole body requires considerable effort.

It is also known from DE-PS 3 206 499 a device for introducing gases into metallurgical vessels, which consists of a sheet-jacketed refractory stone, and in which the gas is passed through gas passages made of ceramic fiber material. For example, also by means of an annular joint filled with fibrous material, which is present between the lateral surface of the frustoconical stone and the sheet metal jacket. This probably achieves a gas outflow which is favorable for the mixing effect in the vessel and has an annular cross section, but the device requires relatively high operating pressures for the gas to be introduced due to the flow conditions in the fibrous-filled gas passage of the same passage cross section, and the sheet metal jacket at the outlet cross section of the gas passage also scales relatively quickly, which contributes to premature wear of the neighboring refractory material.

From GB-PS 1 594 631 Fig. 3 a device for introducing gases into metallurgical vessels is known, which is composed of a refractory base body and an appropriately inserted, also refractory inner body, the gas passages being formed by longitudinal grooves provided in the inner body are distributed in the mutually contacting peripheral surfaces of the inner body and the base body. Nothing is described in GB-PS 1 594 631 about the exact design of these grooves, in particular about their cross-sectional shape in the longitudinal direction of the device. Another embodiment is known from GB-PS-1594631, which has a gas passage with a continuously narrowing circular cross-section.

The object of the present invention is to improve the mode of operation of a injection device of the type mentioned at the outset and to simplify its production.

For this purpose, the invention proposes to design the gas passages in the refractory molded body of the device as nozzles with a cross-section which is constantly narrowing in the direction as nozzles with a cross-section which narrows continuously in the direction from the outside gas chamber to the outlet side in such a way that speed losses to be expected in the gas flow are automatically compensated for and not due to special compressed gas with higher pressures than usual. In addition, due to the constellation of the outlet cross sections on the outlet side of the injection device, a crown-shaped gas jet bundle flows, which is extremely useful for the mixing effect, the gas outlets being made exclusively of refractory material, i.e. without a sheet metal jacket, which leads to a significantly longer durability of the device and also allows a shortening of the sheet metal jacket, so that the gas outlet side remains completely free from scaling, wear-promoting sheet metal.

In addition, the device is easy to manufacture, in particular if the refractory molded body is constructed in several parts according to a further proposal according to the invention and consists of a base body and at least one inner body suitably inserted therein, the nozzles between the base body and the inner body on their touching Circumferential surfaces are distributed. It is particularly expedient here if the nozzles are formed by grooves provided in the lateral surface of the inner body with converging longitudinal flanks and the base body.

If the number of nozzles is to be increased and the effect of the injection device per unit area is to be intensified, this can be accomplished simply and expediently by arranging at least one sleeve in the base body and an inner body therein, and grooves on the lateral surfaces of the sleeve and inner body are provided to form nozzles. On the other hand, it is just as easy and expedient to increase the gassing area of the injection device with or without intensification by inserting several inner bodies and / or sleeves and inner bodies next to one another in the base body. This gives you a range of common injection devices that can be produced on the same manufacturing basis.

With regard to further education and The arrangement of the injection device parts provides that at least the inner bodies and sleeves have the shape of truncated bodies and are arranged coaxially one inside the other. This preferably also applies to base bodies, provided that they do not have several inner bodies with or without sleeves. In principle, however, the outer shape of the base body can differ from the shape of the inner body and sleeves. If blunted bodies are used as the inner body and sleeves, it is advantageous to design the base body, inner body and sleeve on the contact surfaces with self-locking conicity, in order to particularly facilitate the assembly of the device.

Furthermore, a feature of the invention is that the inner body and the sleeve are shortened relative to the base body by the height of the gas chamber and spacers with gas passages are provided between their base surfaces and the base plate of the sheet metal jacket. This results in an uncomplicated design of the gas chamber.

As an alternative to the explanations discussed above, according to which the injection device is based on a multi-part refractory shaped body, it may also be appropriate to start from a one-piece refractory shaped body, which is then useful using a mold core made of removable material which has the outer shape of the nozzles and the gas chamber will be produced. Such a core is inserted into a shape that gives shape to the shaped body before the refractory material is filled in and compressed.

• Fig. 1 zeigt eine kegelstumpfförmige Ausführung einer Eindüsvorrichtung im Längsschnitt,
• Fig. 2 die Draufsicht auf die Gasaustrittsseite derselben Vorrichtung,
• Fig. 3 einen Schnitt nach der Linie A-A der Fig. 1,
• Fig. 6 und Fig. 7 weitere Ausführungsbeispiele der Vorrichtung in ähnlicher Darstellungsweise wie in Fig. 3.

The invention is explained below with reference to the drawing in several embodiments.

• 1 shows a frustoconical design of a injection device in longitudinal section,
• 2 is a top view of the gas outlet side of the same device,
• 3 shows a section along the line AA of FIG. 1,
• FIGS. 6 and 7 show further exemplary embodiments of the device in a representation similar to that in FIG. 3.

In the exemplary embodiment according to FIGS. 1 to 5, 1 means the refractory lining of a metallurgical vessel, not shown in detail, which has a base opening 2, for example arranged in a perforated brick, into which the injection device 30 is inserted from the outside by means of mortar 3. Specifically, the injection device 30 has a frustoconical base body 4 with a central, conical bore 5, in which an inner frustum-shaped body 6 is inserted. Here, the cone between the bore 5 and the body 6 corresponds to a self-locking conical fit, so that the body 6 is automatically held in place when it is inserted into the bore 5 in the operating position reached. On the circumference, the base body 4 is provided with a sheet metal jacket 7 up to approximately half the height, which has a sheet metal base 8 with a central gas supply 9 on the outer end face of the device 30. Beyond the gas supply 9, the base body 4 has a central recess 10 in the end face, the diameter of which is smaller than its outer diameter, but larger than the outer diameter of the inner body 6, which is shortened by the height of the recess 10, so that a chamber 11 arises for the gas to be introduced. Spacers arranged in the chamber 11 in the form of rings 12 and 13 which are centered one inside the other ensure a uniform distance between the sheet metal base 8 on the one hand and the base body 4 and the inner body 6 on the other hand, the inner ring 13 supporting the inner body 6 outside the gas supply 9 and radial Has gas passages 14 for passing the gas flowing through the gas supply 9 into the peripheral region of the gas chamber 11.

To guide the gas from the chamber 11 to the outlet side 15 of the injection device 30, longitudinal grooves 16 provided on the outside on the inner body 6 are used, the flanks 17 of which converge (FIGS. 4 and 5) and which form 4 nozzles 18 with the bore 5 of the base body. With their slot-shaped outlet cross-sections on the outlet side 15, these result in an articulated ring formation with which the melt can be gassed particularly effectively or with which other media can be applied. The base body 4 and the inner body 6 are made of conventional refractory materials with no special gas permeability, so that the gas flow necessarily takes place in the nozzles 18, in which the gas flows at the same speed, since gas pressure losses occurring on the gas path due to the decrease in cross section given to the gas outlet side 15 the nozzle 18 is compensated.

The result is an optimal nozzle effect which, not least, counteracts the penetration of melt, in particular low-viscosity steels, into the nozzles 18 and thus prevents the risk of wear on the gas outlet side 15, which mainly determines the service life of the injection device 30.

6 has a truncated pyramid as the base body 19 with a likewise central, conical bore 5, into which an internally and externally identical conical sleeve 20 and in turn a conical inner body 21 are inserted is. In the lateral surfaces of the sleeve 20 and the inner body 21, longitudinal grooves 16 are provided in order to create said nozzles 18 between the base body 19 and the sleeve 20, as well as this and the inner body 21, which are radially offset from one another and an intensive gassing of melt on one preferably treatment area within the metallurgical vessel. If more than one cone sleeve 20 is provided, the fumigation intensity is increased further.

A more injecting device 30 oriented towards the surface effect can be seen from FIG. 7, where the base body 22 is a truncated pyramid with a rectangular cross section. In the longitudinal extension of the rectangle, two truncated pyramids are inserted as inner bodies 23 in correspondingly counter-profiled bores 24. Each body 23 has two grooves 16 on the trapezoidal four circumferential surfaces to form nozzles 18, so that there are eight nozzles on each inner body 23, which form a square-like formation with their outlet cross sections. Here too, the taper of the bodies 23 and bores 24 can be self-locking.

Basically, depending on the choice of the cross section of the base body 4, 19, 22 and the number of sleeves 20 and inner bodies 6, 20, 21, 23 arranged therein, the gassing of the melt by means of the injection device 30 largely onto a special metallurgical vessel (pan, converter or the like). Base body 4, 19, 22 and sleeves 20 and inner body 6, 20, 21, 23 can optionally also have the same thickness in the longitudinal direction and, for example, polygonal or oval cross sections can also be used instead of a preferably round cross section for the bore, sleeve and inner body. Furthermore, it is possible to deviate from the elongated cross-sectional shape of the nozzles 18, for example to adapt them to the conditions of the flowing medium, the grooves 16, which also shape the nozzles 18, also being provided in the base body 4, 19, 22 or in base and inner bodies be. Furthermore, in an expedient embodiment, the base bodies 4, 19, 22 can in principle be pressed from more insulating refractory material compared to the sleeves 19, and inner bodies 6, 21, 23, which are more made from more wear-resistant refractory material.

In general, base bodies 4, 19, 22, sleeves 20 and inner bodies 6, 21, 23 are produced separately and then assembled with the metal jacket 7. Nevertheless, a joint production of base body, inner body and sleeve can be advantageous if a mold core made of a combustible or gasifiable substance is used, which has a footplate corresponding to the gas chamber 11 and stilts arranged thereon to form the gas nozzles 18. After inserting such a core into a shape formed according to the outer shape of the base body, the refractory material can be filled in and shaken, for example.

Claims (9)

1. Injection device for introducing gases into metallurgical vessels which is replaceably inserted in the refractory vessel lining and comprises a refractory moulded body with gas passages extending from an external gas chamber to the outlet side which together with the gas chamber is surrounded by a sheet metal shell, characterised in that the gas passages (18) are constructed as nozzles with constantly reducing cross-section in the direction from the external gas chamber (11) to the outlet side in such a manner that the drop in velocity which is to be expected of the gas flow along the gas passages (18) is compensated for by the reduction in the cross-section.

2. Device as claimed in Claim 1, characterised in that the moulded body is of multi-part construction and comprises a base body (4,19, 22) and at least one inner body (6, 20, 21, 23) fittingly inserted therein and that the nozzles (18) are distributed between the base body (4, 19, 22) and the inner body (6, 20, 21, 23) on their contacting peripheral surfaces.

3. Device as claimed in Claim 2, characterised in that the nozzles (18) are defined by grooves (16) with converging longitudinal flanks (27) provided in the outer surface of the inner body (6, 20, 21, 23) and the base body (4, 19, 22).

4. Device as claimed in Claim 2 or 3, characterised in that arranged in the base body (19) is at least one sleeve (20) within which in turn is an inner body (21) and grooves (16) are provided on the outer surfaces of the sleeve and inner body to form nozzles (18).

5. Device as claimed in one or more of Claims 2 to 4, characterised in that a plurality of inner bodies (6, 23) and/or sleeves (20) and inner bodies (21) are inserted next to one another in the base body (22).

6. Device as claimed in Claim 5, characterised in that at least the inner bodies (6, 21, 23) and sleeves (20) have the shape of truncated bodies and are arranged coaxially within one another.

7. Device as claimed in one or more of Claims 2 to 6, characterised in that base bodies (4, 19, 22) and inner bodies (6, 21, 23) and sleeves (20) are formed at the contact surfaces with self-locking conicity.

8. Device as claimed in one or more of Claims 2 to 7, characterised in that inner bodies (6, 21, 23) and sleeves (20) are shortened with respect to the base body (4, 19, 22) by the height of the gas chamber (11) and that spacers (13) with gas openings (14) are provided between their base surfaces and the bottom plate (8) of the sheet metal shell (7).

9. Device as claimed in Claim 1, characterised in that the moulded body is of one-piece construction, whereby a moulding core of removable material having the outer shape of the nozzles (18) and the gas chamber (11) is employed.

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