Csp Continuous Casting System With a Roler Hearth Furnace and Pivoting Conveyors

Abstract

The present invention relates to a continuous casting plant (1) including at least one continuous casting section, optionally, at least one reducing unit, at least one separation device, and one or more devices (3) for tempering the strip. In order to increase the production of such casting plants and to expand to-be-conveyed goods, it is proposed that at least one rolling line is arranged parallel to the continuous casting plant (1) with means (10, 10′) for inwardly transferring different slab formats into the line of the continuous casting plant (1).

Description

The invention relates to a continuous casting plant including at least one continuous casting section, optionally, at least one reducing unit, at least one separation device, and one or more devices for tempering the strip, and a downstream rolling train.

The so-called CSP-plants (Compact Strip Production) provide for a continuous and significantly shorter production of hot-rolled strips. Liquid steel is poured from a ladle in a tundish and from the tundish with a pouring tube in a mold. The mold has a shape in form of a funnel that is reduced on both parallel broad sides only in a last third of its height. The mold shape corresponds to a typical contraction course of a cooled steel. The advantage of a funnel, among others, is seen in that steel solidifies substantially stress-free and trouble-free. The rapidly solidified, in this manner, thin slabs having a thickness of about 50 mm are separated by shears before they are heated to a uniform temperature of 1,500° in a conveyor-furnace. Finally, rolling in a finishing train takes place, with finished slabs having a width from 900 to 1600 mm and thickness from 0.8 to 6.53 mm. For producing very thin sheets, six or seven very powerful rolling mill stands are used. Finally, the strip travels over a long cooling line to reels which wind the strip up into a coil. With CSP-plants, a high-quality hot-rolled strip is produced with favorable profile characteristics, better surface quality, and narrow tolerances.

The document EP 1 363 750 B1 discloses a method for operating a continuous casting-rolling plant including at least one slab production line and at least one rolling mill train and further at least one slab-feeding device which technically is independent from the slab production line.

During a production interval of the slab production line, the slab feeding device takes over the delivery of slabs to the rolling mill train in accordance with logistic and/or manufacturing standards up to a maximum output possible. The mentioned further slab-production line is formed as a thick-slab production line, whereby the slab feeding device of the casting-rolling plant receives the slabs from a slab storage in which the prefabricated slabs are tempered during a manufacturing process. Those are reduced in a separate break-down train to a coil-adapted thickness. The coils are fed behind the casting plant immediately to the rolling train.

The object of the present invention is increase of production and expanding the to-be-conveyed goods in a CSP-plant, i.e., in a thin slab plant.

The object is achieved in a continuous casting plant having features of the claim 1 by arranging at least one rolling line parallel to the continuous casting plant with means for inwardly transferring different slab formats into the line of the continuous casting plant.

By the inward transferring of different slab formats from a parallel rolling line, increase in production is achieved by the maximal use of the downstream rolling line and an unlimited use of steel goods.

According to the further development of the invention, for inward transferring of slabs in a continuous casting line, there are provided pivoting or parallel conveyors. Thereby, among others, it is possible to inspect slabs deliverable from the parallel rolling line for processing and to undertake, if necessary, the necessary secondary treatment.

In the embodiment of the inventive continuous casting plant, it is contemplated that the pivoting or parallel conveyors are formed at least partially as hearth furnaces, in particular, as roller hearth furnaces. Thereby, an optimal heating process and an optimal temperature equalization for the inwardly transferred slabs is possible.

A further improvement of the continuous casting plant contemplates that the pivoting conveyors have a transporting device running in a direction opposite the transportation direction of the continuous casting plant, whereby the entire continuous casting plant is made very compact.

An ideal development of the continuous casting plant contemplates that the parallel rolling line has hearth furnace and a break-down train with horizontal and vertical edging stands or a sheet rolling mill stand for reducing the thickness of the inwardly transferable slabs to an entry thickness necessary for a CSP-plant, e.g., between 40 and 70 mm.

With the inventive features, it is advantageously achieved that the continuous casting plant can be followed by one or more tandem-stand rolling mill trains as finishing trains, so that the CSP-plant with a noticeable production increase and expansion for all of the conveyed goods is formed.

The invention will be explained in detail based on a schematically shown embodiment.

The drawings show:

FIG. 1 a CSP-plant with a double-strand continuous casting installation with parallel rolling lines for transferring slabs in a continuous casting plant by a pivot process, and a downstream finishing line.

In a continuous casting plant 1, liquid steel is poured from a pan furnace 2 into an intermediate vessel, not shown in detail, and therefrom is poured with a pouring tube, likewise not shown in detail, in a funnel mold. From the funnel mold, the solidified steel is deflected by a guide stand into a horizontal roller table and is separated there by separation device in thin slab lengths. The thin slabs are fed in a roller hearth furnace 3 for heating to a uniform temperature of about 20°, in which the temperature is tempered. The separated thin slabs with a thickness of about 5.0 mm are delivered into a downstream finishing train 4 in which a thin slab is reduced in several stands 5 to a thickness of from 0.8 to 6.35 mm. The rolled strip is finally fed in a cooling line 6 with a laminar cooling and, finally, is wound up with a reel 7, forming a coil.

In order to increase production of the above-described CSP-plant and to be able to expand the to-be-conveyed goods, next to the continuous casting plant 1, there is arranged a parallel rolling line 8, e.g., with a furnace for conventional thick slabs or medium-thick slabs, and with a two-stand break-down train 9 or a sheet rolling mill stand, in which slabs, which are to be transferred in the continuous casting plant 1, are reduced to CSP-plant thicknesses of about 50 mm. These slabs are transferred from outside in the CSP-line by pivoting or parallel conveyors 10 or 10′, and are heated in the roller hearth furnace arranged therein to the necessary rolling temperature, and their temperature is so tempered that they can finally be fed to the downstream finishing train 4 and are rolled there in a described manner, cooled, and can be wound up into coils.

Claims

1. A continuous casting plant (1), comprising at least one continuous casting section, optionally, at least one reducing unit, at least one separation device, and one or more devices (3) for tempering the strip, and a downstream rolling train (4), characterized in thatat least one rolling line is arranged parallel to the continuous casting plant (1) with means (10, 10′) for inwardly transferring different slab formats into the line of the continuous casting plant (1).

2. A continuous casting plant according to claim 1, characterized in thatfor inwardly transferring the slabs in the line of the continuous casting plant, pivoting or parallel conveyors (10, 10′) are provided.

3. A continuous casting plant according to claim 1, characterized in thatthe pivoting or parallel conveyors (10, 10′) are formed at least partially as hearth furnaces, in particular, as roller hearth furnaces (3).

4. A continuous casting plant according to claim 1, characterized in thatthe pivoting conveyors (10, 10′) have a transporting device running in a direction opposite the transportation direction of the casting plant.

5. A continuous casting plant according to claim 1, characterized in thatthe parallel rolling line (8) has a hearth furnace and a break-down train (9) with horizontal and vertical edging stands or a sheet rolling mill stand for reducing the thickness of the inwardly transferring slabs to an entry thickness necessary for a CSP-plant, e.g., between 40 and 70 mm.

6. A continuous casting plant according to claim 1, characterized in thata tandem-stand train (5) as finishing train (4) with a cooling line (6), reel/s (7) and, optionally, further plant components such as shears and the like are arranged downstream of the continuous casting plant according to claims 1 through 5.