DE2130343A1 - Method and arrangement for preheating pouring ladles - Google Patents

Description

"Procedure and arrangement for preheating Ladles "

The present invention relates to a refractory lined ladle and a method for preheating an already used ladle in front of it Reuse. The invention is of particular use in the continuous casting of steel, although it does not apply to this Area of application is limited.

Intermediate ladles used in continuous casting, generally have a high area-to-volume ratio on what leads to the formation of pan bear. Pfannenbär is a "solidified layer of steel and slag, which are returned after the gloss in a pouring pan

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Patent attorneys Dipl.-Ing. Martin Licht, Dipl.-Wirtsch.-Ing. Axel Hansmann, Dipl.-Phys. Sebastian Herrmann

remain. Usually this ladle has to be removed mechanically before the pouring ladle again Can be used · If an attempt is made to remove a panache by melting it will be oxidized he and the molten iron oxide flows to the nozzle bore and tends to clog nozzles. The pouring pan must be preheated before use in order to minimize the formation of a pan-bear keep. If the ladle is to be reused, the preheating temperature for the ladle should be around 1370 ° C be limited what the melting temperature of iron oxide is. The presence of alumina in the composition des Pfannenbärs lowers the melting temperature of the Pfannenbärs to around 1205-126O ° C. “This temperature limit lowers the amount of preheating exerted on the refractory lining in a given period of time can be.

A pouring ladle is usually attached to a preheating station preheated, which is removed from the working position. Therefore, the ladle can last for a long period of time preheated without interfering with other operations required in preparation for the cast.

When a pouring ladle is preheated in a conventional manner, the pouring nozzle is often insufficiently heated. this is based on a partial vacuum in the vessel through which one Air infiltration is allowed through the nozzle. Because of the buoyancy effect, the nozzle is at the lowest point is in the ladle, the point with the least pressure. The air infiltration cools the nozzle and At the start of casting, the liquid steel has a tendency to solidify in the relatively cold Otts. The melted one Stiff the pan bear also has a tendency to freeze when it comes into contact with the pouring nozzle,

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The object on which the present invention is based is therefore to create a method for warning a pouring ladle, by means of which the clogging of the pouring nozzle by molten iron oxide is avoided.

Furthermore, an arrangement is to be created according to the invention, through which a properly preheated ladle ejects molten substance from the pan bear and not retains

According to the present invention, a method for Preheating of an already used ladle created before it is reused. The ladle includes a Open at the top, refractory lined vessel, which is in the Bottom wall a nozzle or pouring nozzle for the discharge of having molten metal. The method according to the present invention is characterized in that the The vessel is rotated around a horizontal axis in a preheating position, then the vessel on a burner and a is aligned with a lid cooperating outlet device, wherein the lid is the open top end of the The vessel is closed and the burner is introduced into the vessel and the escape of exhaust gases from the vessel through corresponding openings in the lid allow then the burner is ignited and the vessel is brought to a temperature above the melting point of the one remaining in the vessel Metal is heated, and that the molten metal at the lowest point of the vessel can flow out of it leaves.

The invention will emerge more clearly from the following description and the accompanying drawings, in which an embodiment of the invention is described and illustrated.

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Fig. 1 is a plan view of the pouring tundish according to the invention,

Fig. 2 is a cross sectional view of the ladle along the line H-II in Fig. 1,

3 is a right side elevational view of the ladle in FIGS. 1 and 3

Figure 4 is an isometric partially cut away View of the pouring ladle and the preheating installation.

As shown in the drawing, one is refractory lined Ladle 10 equipped with a lid 12, which serves to reduce heat loss while metal is poured from the ladle. The lid has a filling opening 14 which receives the pouring stream from a pan, and a viewing opening 15 for observing the level of the liquid metal in the tundish and other operations. These openings in the cover are also used as attachment points for a preheating burner and used for the discharge of exhaust gases, as will be explained below. The burner is removed when the tundish is moved to its operative position just prior to receiving molten metal will.

The pouring pan is rotated 90 ° around a horizontal axis and preheated in this position. Facilities for turning the pouring ladle, for draining molten iron oxide, which is in the form of a solidified layer has remained in the pouring pan, and are used to fasten the lid to the pouring intermediate provided according to the invention.

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The cover 12 has a lined with refractory material 17 Steel jacket 16 and eye tabs 18 which are aligned with eyelets 19 on the intermediate ladle 10 are. The lid is fastened in this position in that the eye tabs 18 are fastened by bolts or other means suitable means are attached to the eyelashes 19.

The pouring tundish 10 is equipped with support pins 21, around which it can be rotated around a horizontal axis. The common axis of the pin 21 lies on one Line of equilibrium of the pouring tundish and above their focus. The pouring tundish carries a nozzle 23 in its bottom wall and an exhaust passage or drain 24 in its side wall, preferably in its upper peripheral edge. The drain is, as shown in the drawing, lined on three sides by the refractory lining of the pouring tundish, and on one side by the refractory lining 17 of the lid. The nozzle 23 is at the lowest point when the pouring double pan is in its horizontal or pouring division, while the outlet passage 24 is at the lowest point when the tundish is in its vertical position or preheating position.

In operation, when the Giesszwisohenpfanne 10 is to be preheated, it is around the pin 21 in its vertical Rotated position in which the drain 24 reaches the lowest point. As shown in Fig. 4, the pouring tundish brought into a position in which its cover 12 is in contact with an outlet device or an exhaust duct 28 arrives. A burner 30 is aligned with the fill port 14, and the viewing port 15 is at the exhaust port 32 aligned to provide a continuous gas outlet from the interior of the pouring twin pan through the sohaoht

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28 to form. When the pan bear or the layer of solidified iron oxide is heated above its melting point, the melted pan bear runs down the sides of the pouring pan 10 and through the drain 2k into a suitable collecting vessel (not shown).

In the vertical position, a pouring pan can be heated to a temperature of over 1260 ° C (up to around 1650 ° C) must be preheated. Since the pan-bear formation is a Function of the vessel temperature and the surface-volume ratio is, due to the higher preheating, the formation of pan bear is reduced each time a Prevents pouring pan without the disadvantages of mechanical removal of the pans. There is also When preheating the nozzle, the nozzle is no longer at the point of the lowest pressure, as it is significantly above the lowest point in the ladle. So the melted pan bear material is eager to get off the nozzle to flow away to the drain 24.

A preheating station for heating the casting ladle in its vertical position according to the present invention requires less space than a traditional horizontal station. A fixed vertical preheating station is also easier to maintain than a conventional station, the cantilever burner and in the shaft suspended refractory · «material required.

From the above description it is clear that, according to the invention, the clogging of the pouring nozzle of a Casting pan is prevented by molten iron oxide and this molten pan bear material is ejected and is not held back.

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Claims (6)

PATENT CLAIMS x 1. Procedure for preheating a ready, used tundish before re-use, which consists of an open-topped, fire-proof lined vessel and ■ with a nozzle in the bottom wall of the vessel for the outlet of molten] metal is provided, characterized in that the vessel in a horizontal axis in a Preheating position is rotated, aligned with a co-operating with a lid burner and exhaust outlet device the lid closes the open top end of the vessel and the introduction of the burner into the The vessel and the escape of exhaust gases from the vessel through corresponding openings in the lid are then permitted the burner is inserted and the vessel is brought to a temperature above the melting temperature of the one remaining in the vessel Metal is heated, and the molten metal at the lowest point of the vessel is drained from this. 2. The method according to claim 1 for preheating a Giesszwi8chenpfanne after pouring molten iron oxide through the nozzle of the Giesszwi8chenpfanne, characterized in that the vessel is ^{heated to a temperature between 1260 0} G and 1650 * C, at which a solidified layer of steel and Slag is melted on the walls of the vessel. 3. Arrangement for preheating a pouring pan with an outlet nozzle in the bottom wall by means of a burner for carrying out the method according to claim 1, characterized through a fire-proof lined vessel (OK), 109853/1259 whose open upper end is closed by a refractory lined lid (12), the filling and Has viewing openings (14 or 15), means (18, 19) for releasably attaching the lid (12) to the vessel (lO), a refractory lined outlet passage (24) in a side wall of the vessel, attached to the vessel holding devices (21) for rotating the Vessel around a horizontal axis, whereby the outlet passage (24) to the lowest point of the tilted vessel is moved in the preheating position of the casting ladle, one arranged in the vicinity of the burner (30) Exhaust gas outlet device (32, 28) and a position of the exhaust gas outlet device and the burner in which they are on the filling or viewing openings (14 or 15) of the vessel lid (12) are aligned. 4. Arrangement according to claim 3, characterized in that the means for releasably fastening the cover to the vessel consist of eye tabs (18 or 19) and connecting bolts provided on the vessel and on the lid, through the position of the filling and inspection openings (14, 15) in relation to the burner and the exhaust gas outlet device is determined. 5. Arrangement according to claim 3 »characterized in that that the mounting device for the rotational movement of the Pouring pan from two equiaxed on the vessel attached pivot pin (21), the common axis of which is on a line of equilibrium above the center of gravity the pouring pan lies, 6. Arrangement according to claim 3ι, characterized in that that the drain passage (24) «is a drain opening which is formed in the upper peripheral edge by the refractory linings of the vessel or «tea cover. 109853/1259 Blank page