Method and device for descaling a metallic surface and installation for producing semifinished metallic products

Abstract

A method for descaling a metal surface of a semifinished metal product, including the steps of: guiding the semifinished metal product in a transporting direction past nozzle head parts that rotate about rotation axes and are arranged alongside one another transversely to the transporting direction; and directing high-pressure fluid jets produced by nozzle elements arranged on the rotating nozzle head parts at the metal surface. The fluid jets also being blasted as far as the metal surface at a narrow point between two immediately adjacent nozzle head parts. The nozzle head parts rotate synchronously with one another at a preset angular position with respect to a rotation angle of a particular rotation axis of the nozzle head parts. The fluid jets produced by the nozzle elements are always blasted onto the metal surface past one another without coming into contact with one another.

Claims

1. A method for descaling a metal surface of a semifinished metal product, comprising the steps of: guiding the semifinished metal product in transporting direction past nozzle head parts that rotate about rotation axes and are arranged alongside one another transversely to the transporting direction; directing high-pressure fluid jets produced by nozzle elements arranged on the rotating nozzle head parts at the metal surface, said fluid jets also being capable of being blasted as far as the metal surface at a narrow point between two immediately adjacent nozzle head parts; and rotating the nozzle head parts synchronously with one another at a preset angular position with respect to a rotation angle of a particular rotation axis of the nozzle head parts so that the nozzle elements of the two immediately adjacent nozzle head parts are never immediately adjacent and preventing the fluid jets produced by the nozzle elements of the two immediately adjacent nozzle head parts from overlapping so that the fluid jets are always blasted onto the metal surface past one another without coming into contact with one another at the narrow point.

2. The method as claimed in claim 1, wherein the nozzle head parts rotate at rotational speeds that are synchronized with one another.

3. The method as claimed in claim 1, including accelerating the nozzle head parts in a synchronized manner.

4. The method as claimed in claim 1, including calibrating the respective angular positions of the nozzle head parts with one another.

5. The method as claimed in claim 1, wherein the nozzle elements of two immediately adjacent nozzle head parts always pass the narrow point alternately so that the fluid jets produced by the nozzle elements are always blasted onto the metal surface past one another without coming into contact with one another.

6. The method as claimed in claim 1, wherein the nozzle elements of two immediately adjacent nozzle head parts are always guided past the narrow point with a time lag.

7. An apparatus for carrying out a method for descaling a metal surface of a semifinished metal product, comprising: a nozzle device, past which the semifinished metal product is guidable in a transporting direction, wherein the nozzle device has a plurality of nozzle head parts that rotate about rotation axes, said nozzle head parts having nozzle elements that produce high-pressure fluid jets that are directed at the metal surface, wherein the nozzle head parts are arranged alongside one another so that the fluid jets produced by the nozzle elements are also blasted as far as the metal surface at a narrow point defined as a point between two immediately adjacent nozzle head parts, wherein the rotating nozzle head parts are each always arranged, in terms of angular position, oriented with respect to one another so the nozzle elements of the two immediately adjacent nozzle head parts are never immediately adjacent and so that the fluid jets produced by the nozzle elements of the two immediately adjacent nozzle head parts are prevented from overlapping so that the fluid jets are always blasted onto the metal surface past one another without coming into contact with one another at the narrow point; and wherein the nozzle head parts are connected together in a mechanically and/or electronically interacting manner so that the nozzle head parts of the nozzle device are each always arranged oriented at preset angular positions with respect to one another.

8. The apparatus as claimed in claim 7, wherein the nozzle elements of two immediately adjacent nozzle head parts are always arranged, in terms of their angular positions, oriented with respect to one another so that the fluid jets produced by the nozzle elements are always able to be blasted onto the metal surface past one another without coming into contact with one another.

9. The apparatus as claimed in claim 7, further comprising a drive device that drives the nozzle head parts in a synchronized manner in terms of rotational properties.

10. The apparatus as claimed in claim 7, wherein the nozzle elements of two immediately adjacent nozzle head parts are arranged, in terms of their angular position, offset by more than 5 with respect to one another.

11. The apparatus as claimed in claim 10, wherein the nozzle elements of two immediately adjacent nozzle head parts are arranged offset by more than 15 with respect to one another.

12. The apparatus as claimed in claim 11, wherein the nozzle elements of two immediately adjacent nozzle head parts are arranged offset by 45 with respect to one another.

13. An installation for producing semifinished metal products comprising an apparatus according to claim 7 for descaling metal surfaces of the semifinished metal products.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) FIG. 1 schematically shows an installation for producing a semifinished metal product; and

(3) FIG. 2 schematically shows a plan view of a nozzle head part arrangement of a nozzle device of the descaling apparatus of the installation from FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(4) The present inventive apparatus 1 for descaling metal surfaces 2 and 3 of a semifinished metal product 4 is integrated, according to the exemplary embodiment shown in FIG. 1, into an installation 5 for producing the semifinished metal product 4. The installation 5 in this case comprises a casting machine 6 having a mold 7 and a casting bow 8, wherein the semifinished metal product 4 emerging from the casting bow 8 and in the form of a metal strip 9 is subsequently conveyed in the transporting direction 13 through various roughing stands 10 and stands 11 of a production line 12. Also provided is an induction furnace 14 by means of which the metal strip 9 is raised to a higher temperature following a rolling operation in the roughing stands 10. The descaling of the surfaces 2 and 3 takes place downstream of the induction furnace 14 by way of the apparatus 1 for descaling, wherein the apparatus 1 comprises a descaling device 15.

(5) The apparatus 1 is characterized in particular by a nozzle device 16 which consists, both above the metal strip 9 and below the metal strip 9, in each case of an arrangement of seven nozzle head parts 18 arranged alongside one another in a row 17 (cf. also FIG. 2). The row 17 extends in this case in the widthwise direction 19 of the metal strip 9 transversely to the transporting direction 13.

(6) Each of the nozzle head parts 18 that are present is mounted in the nozzle device 16 such that it rotates about a separate rotation axis 20 (only designated by way of example). Furthermore, each of the nozzle head parts 18 has four nozzle elements 22, 23, 24 and 25 that are arranged in a manner offset through 90 with respect to one another around the outer periphery 21 of the nozzle head parts 18.

(7) The nozzle elements 22 to 25 have at least one outlet opening (not shown) from which a high-pressure fluid jet (not shown here) can emerge, wherein the nozzle elements 22 to 25 are arranged such that the fluid jets produced thereby are blasted onto the particular surface 2 or 3. All of the nozzle elements 22 to 25 rotate in this case in the same direction, in the direction of rotation 26, about their particular rotation axis 20. The rotation axes 20 are in this case located on a common fictitious connecting line 27.

(8) In order to prevent individual fluid jets from crossing or touching one another such that their jet actions reduce one another or cancel one another out, the nozzle head parts 18 are arranged alongside one another such that the fluid jets produced by the nozzle elements 22, 23, 24 and 25 are always able to be blasted onto the metal surface 2, 3 past one another without coming into contact with one another at a particular narrow point 30 between two immediately adjacent nozzle head parts 18.

(9) To this end, the individual rotating nozzle head parts 18 are arranged, with regard to their particular angular position 31 or 32 (only designated by way of example here), in a manner oriented with respect to one another such that the nozzle elements 22, 23, 24, 25 of two immediately adjacent nozzle head parts 18 always pass alternately through the particular narrow point 30.

(10) This means that first ones of the nozzle head parts 18 are at a first angular position 31 with a rotation angle 33 (only designated by way of example) of 45 with regard to the fictitious connecting line 20, and further ones of the nozzle head parts 18, which are directly adjacent, are at a further angular position 32 with a further rotation angle (not indicated) of 0 with regard to the fictitious connecting line 20, as is shown by way of example with regard to the snapshot illustrated in FIG. 2.

(11) For example, the nozzle elements 23 and 25, respectively, of some of the nozzle head parts 18 are congruent with the fictitious connecting line 20 (rotation angle=0); they are thus temporarily positioned at the particular narrow point 30 of two immediately adjacent nozzle head parts 18, while the nozzle elements 24 and 25, and 22 and 23, respectively, of the nozzle head parts 18 directly adjacent thereto, are arranged in a manner rotated through 45 with respect to the narrow point 30 or from the fictitious connecting line 20.

(12) As a result, it is possible to ensure in a particularly simple manner in terms of structure that the nozzle elements 22, 23, 24, 25 of two immediately adjacent nozzle head parts 18 are always guided past the narrow point 30 with a corresponding time lag.

(13) Advantageously, the rotary movements of the individual nozzle head parts (18) and of their drive means (not shown here) are in this case preferably perpetually synchronized in a correct position, such that the individual nozzle head parts (18) always rotate in an oriented manner with respect to one another, as required.

(14) It goes without saying that the exemplary embodiment explained here is merely a first configuration of the apparatus for descaling according to the invention. In this respect, the configuration of the invention is not limited to this exemplary embodiment.

LIST OF REFERENCE SIGNS

(15) 1 Apparatus for descaling 2 First metal surface 3 Second metal surface 4 Semifinished metal product 5 Installation for production 6 Casting machine 7 Mold 8 Casting bow 9 Metal strip 10 Roughing stands 11 Stands 12 Production line 13 Transporting direction 14 Induction furnace 15 Descaling device 16 Nozzle device 17 Row 18 Nozzle head parts 19 Widthwise direction 20 Rotation axis 21 Outer periphery 22 First nozzle element 23 Second nozzle element 24 Third nozzle element 25 Fourth nozzle element 26 Direction of rotation 27 Fictitious connecting line 30 Narrow points 31 First angular positions 32 Second angular positions 33 First rotation angle