DEVICE AND METHOD FOR DESCALING A WORKPIECE IN MOTION

Abstract

The invention relates to a device and a method for descaling a workpiece, which is in motion in relation to the device in a movement direction (X). The device (10) comprises a rotor head (14), which is rotatable about an axis of rotation (R), which is inclined diagonally at an angle () with respect to an orthogonal on a surface (20) of the workpiece (12). Furthermore, the device comprises multiple jet nozzles (16), which are attached on the rotor head (14), wherein a liquid (18), in particular water, is dispensable onto the workpiece (12) at an angle of attack () inclined to the surface (20) of the workpiece (12) from the jet nozzles (16). The jet nozzles (16) are fixedly attached on the rotor head (14) such that during rotation of the rotor head (14) about its axis of rotation (R), the spraying direction (S) of the liquid (18) dispensed from the jet nozzles (16), with respect to a projection in a plane parallel to the surface (20) of the workpiece (12), is aligned opposing, i.e., at a spraying angle () of approximately 180, the movement direction (X) of the workpiece (12).

Claims

1. A device (10) for descaling a workpiece (12), preferably a hot rolled stock, in motion in a movement direction (X) in relation to the device (10), comprising at least one rotor head (14) rotatable about an axis of rotation (R), to which multiple jet nozzles (16) are attached, wherein a liquid (18), in particular water, can be dispensed from the jet nozzles (16) onto the workpiece (12) at an angle of attack () inclined with respect to an orthogonal on a surface (20) of the workpiece (12), characterized in that the jet nozzles (16) are attached to the rotor head (14) in such a way that during rotation of the rotor head (14) about its axis of rotation (R), the spraying direction (S) of the liquid (18) dispensed from the jet nozzles (16), with respect to a projection in a plane parallel to the surface (20) of the workpiece (12), is aligned permanently opposed, i.e., at a spraying angle () between 170 and 190, preferably at a spraying angle () of 180, to the movement direction (X) of the workpiece (12) and at the same time the angle of attack () for all jet nozzles (16) remains constant, and a collection unit (22) is provided, which is arranged upstream from the rotor head (14) with respect to the movement direction (X) of the rolled stock in such a way that both the liquid (18) dispensed from the jet nozzles (16), after rebounding from the surface (20) of the workpiece (12), and also the scale removed by means of the liquid (18) from the surface (20) of the workpiece (12) are introducible in a targeted manner into the collection unit (22).

2. The device (10) as claimed in claim 1, characterized in that the majority of the jet nozzles (16) on the rotor head (14) are attached at radial distances (s.sub.1; s.sub.2; s.sub.3) of different amounts to its axis of rotation (R), wherein a greater volume flow ({dot over (V)}.sub.1; {dot over (V)}.sub.2; {dot over (V)}.sub.3) of liquid (18) is dispensable from a jet nozzle (16.1; 16.2; 16.3) which has a greater radial distance to the axis of rotation (R) than in comparison to a jet nozzle which has a smaller radial distance to the axis of rotation (R).

3. The device (10) as claimed in claim 1, characterized in that the rotor head (14) is arranged in relation to the collection unit (22) such that the liquid (18) is dispensed from the jet nozzles (16) exclusively in the direction of the collection unit (22).

4. The device (10) as claimed in claim 1, characterized in that the positioning of the rotor head (14) in relation to the movement direction of the workpiece (12) and the attachment of at least one jet nozzle (16), preferably all jet nozzles (16), to the rotor head (14) are selected such that the spraying direction (S) of the at least one jet nozzle (16), preferably all jet nozzles (16), in which the liquid (18) is dispensed, extends precisely opposing the movement direction (X) in the case of a projection in a plane parallel to the surface (20) of the workpiece (12) and thus the spraying angle () between the spraying direction (S) and the movement direction (X) is precisely 180.

5. The device (10) as claimed in claim 1, characterized in that the collection unit (22) is provided with at least one drainpipe (26), through which the cleaning liquid and removed scale can be discharged from the collection unit (22).

6. The device (10) as claimed in claim 1, characterized in that the collection unit (22) is equipped with a conveyor unit (27), by means of which the removed scale is transportable inside the collection unit (22) in the direction of an opening of the drainpipe (26), preferably the conveyor unit (27) has at least one flushing nozzle (28), from which a fluid is dispensable.

7. The device (10) as claimed in claim 1, characterized in that individual rotors of a rotor module can be depressurized individually and/or in groups to adapt the dispensing of the liquid (18) transversely to the movement direction (X) of the workpiece (16).

8. The device (10) as claimed in claim 1, characterized in that a cover unit (23.2) is arranged between the collection unit (22) and the rotor head (14), which extends from the collection unit (22) up to directly at the rotor head (14) in such a way that a section between the rotor head (14) and an edge of the cover unit (23.2) is passage-free with respect to scale particles.

9. The device (10) as claimed in claim 1, characterized in that the rotor head (14) is inclined with its axis of rotation (R) with respect to an orthogonal on a surface (20) of the workpiece (12) diagonally at an angle (), wherein the jet nozzles (16) are each fixedly attached on the rotor head (14), preferably the jet nozzles (16) are arranged with the longitudinal axes (L) thereof parallel to the axis of rotation (R) of the rotor head (14).

10. A method for descaling a workpiece (12), preferably a hot rolled stock, which is in motion in a movement direction (X) in relation to a device (10) having at least one rotor head (14) rotatable about an axis of rotation (R), on which multiple jet nozzles (16) are attached, wherein a liquid (18), in particular water, is dispensed from the jet nozzles (16), while the rotor head (14) is rotated about its axis of rotation (R), onto the workpiece (12) at an angle of attack () inclined to the surface (20) of the workpiece (12), characterized in that during rotation of the rotor head (14) about its axis of rotation (R), the spraying direction (S) of the liquid (18) dispensed from the jet nozzles (16), with respect to a projection in a plane parallel to the surface (20) of the workpiece (12), is aligned permanently opposed, i.e., at a spraying angle () between 170 and 190, preferably at a spraying angle () of 180, to the movement direction (X) of the workpiece (12) and at the same time the angle of attack () for all jet nozzles (16) remains constant, and both the liquid (18) dispensed from the jet nozzles (16), after rebounding from the surface (20) of the workpiece (12), and also the scale removed by means of the liquid (18) from the surface (20) of the workpiece (12) are introduced in a targeted manner into a collection unit (22).

11. The method as claimed in claim 10, characterized in that the speed at which the at least one rotor head (14) is rotated about its axis of rotation (R) is adapted by means of a control unit (34) to the feed velocity at which the workpiece (12) is in motion in the movement direction (X), preferably the adaptation of the speed of the rotor head (14) to the feed velocity of the workpiece (12) takes place in a targeted manner.

12. The method as claimed in claim 10 or 11, characterized in that volume flows of different amounts of liquid (18) are sprayed out of a plurality of jet nozzles (16) which are attached on the rotor head (14) at radial distances (s.sub.1; s.sub.2; s.sub.3) of different amounts to its axis of rotation (R), wherein a greater volume flow ({dot over (V)}.sub.1; {dot over (V)}.sub.2; {dot over (V)}.sub.3) of liquid (18) is sprayed from a jet nozzle (16.1; 16.2; 16.3) which has a greater radial distance to the axis of rotation (R) than in comparison to a jet nozzle which has a smaller radial distance to the axis of rotation (R).

13. The device (10) as claimed in claim 1, characterized in that a first rotor head arrangement and a second jet nozzle arrangement are provided, wherein the rotor head arrangement is formed in each case from a rotor head pair (29) or from a rotor module pair (31), and the first and second arrangement are arranged in succession and in particular adjoining one another with respect to the movement direction (X) of the workpiece (12), preferably in a normal mode, liquid (18) is only dispensed onto the workpiece (12) from the jet nozzles (16) of the first rotor head arrangement (14.1), wherein in a special mode, the jet nozzles (16) of the second jet nozzle arrangement (14.2) can be switched on or are switched on, and therefore liquid (18) is also dispensed onto the workpiece (12) from the jet nozzles (16) of the second jet nozzle arrangement (14.2), and both rotor head arrangements (14.1, 14.2) are then accordingly used to descale the workpiece (12).

14. The device (10) as claimed in claim 1, characterized in that a scale detection unit (32) arranged downstream of the rotor head (14) with respect to the movement direction (X) of the workpiece (12) and a control unit (34), to which the scale detection unit (32) and the at least one rotor head (14) are connected for signaling, are provided, wherein remaining scale on the surface (20) of the workpiece (12) is detectable or is detected using the scale detection unit (32), wherein the control unit (34) is configured by programming such that the descaling quality of the workpiece (12) is compared to a predetermined target value on the basis of the signals of the scale detection unit (32), and a high-pressure pump unit, which has a fluid connection to the jet nozzles (16) of the rotor head (14), is controlled, preferably regulated, in dependence thereon.

15. The device (10) as claimed in claim 14, characterized in that the jet nozzles (16) of the rotor head arrangement (14.2) which can be switched on are put into operation, specifically into the special mode, in dependence on the signals of the scale detection unit (32).

16. The device (10) as claimed in claim 14, characterized in that a pressure, at which the liquid (18) is sprayed out of the jet nozzles (16), is settable or is set in dependence on the signals of the scale detection unit (32) by means of an actuation of the high-pressure pump unit.

17. The device (10) as claimed in claim 14, characterized in that a distance (A) of the rotor head to the surface (20) of the workpiece (12) is settable or is set, specifically as a function of the signals of the scale detection unit (32).

18. The device (10) as claimed in claim 1, characterized by a rotor head pair (29) or a rotor module pair (31), in which at least one rotor head (14) is arranged in each case above and below the moving workpiece (12), wherein the pressure at which a liquid (18) is dispensed onto the workpiece (12) by the jet nozzles (16) of the rotor head arranged below the workpiece (12) is greater than in the case of the jet nozzles (16) of the rotor head arranged above the workpiece (12).

Description

[0025] In the figures:

[0026] FIG. 1 shows a schematic simplified side view of a device according to the invention,

[0027] FIG. 2 shows a side view of a rotor head of the device from FIG. 1,

[0028] FIG. 3a,

[0029] FIG. 3b, and

[0030] FIG. 3c each show a schematic relationship between a spraying direction of jet nozzles of a device according to FIG. 1 and a movement direction, in which a workpiece is moved past this device,

[0031] FIG. 4 shows a schematic simplified top view of a device according to the invention according to a further embodiment,

[0032] FIG. 5 shows a simplified cross-sectional view of a collection unit of the device from FIG. 4,

[0033] FIG. 6 shows a simplified side view of a rotor head pair, in which rotor heads according to FIG. 2 are arranged in each case on an upper side and on a lower side of a workpiece to be descaled,

[0034] FIG. 7 shows a simplified frontal view of a rotor module, in which a plurality of rotor heads are arranged adjacent to one another and transversely to the movement direction of the workpiece,

[0035] FIG. 8 shows a possible arrangement of jet nozzles on a rotor head for use in a device according to FIG. 1 or according to FIG. 4,

[0036] FIG. 9a,

[0037] FIG. 9b each show spray pictures which form on the surface of a workpiece with liquid sprayed on the workpiece,

[0038] FIG. 10 shows a flow chart according to which the invention is used in practice, and

[0039] FIGS. 11, 12 each show side views of a rotor head according to further embodiments of the invention.

[0040] Various embodiments of the invention will be described in detail hereafter with reference to FIGS. 1 to 12. In the figures, identical technical features are each identified with identical reference signs. Furthermore, it is to be noted that the illustrations in the drawing are schematically simplified and in particular are not shown to scale. In some figures, Cartesian coordinate systems are shown, for the purpose of spatial orientation of the embodiments according to the invention in relation to a workpiece in motion to be treated.

[0041] A device 10 according to the invention is used for descaling a workpiece 12, which is in motion in relation to the device 10 in a movement direction X. The workpiece 12 can be a hot rolled stock, which is moved past the device 10.

[0042] In the embodiment of FIG. 1, the device 10 comprises a rotor head 14, which can be set into rotation about an axis of rotation R. A rotation of the rotor head 14 about its axis of rotation R is performed by motor means (not shown), for example, by an electric motor. Jet nozzles 16 are attached on an end face of the rotor head 14, which faces toward the workpiece 12. A liquid 18 (symbolized in simplified form by dashed lines in FIG. 1) is sprayed under high pressure onto a surface 20 of the workpiece 12 from the jet nozzles 16 in order to suitably descale the workpiece. For this purpose, the jet nozzles 16 have a fluid connection to a high-pressure pump unit (not shown), by means of which the jet nozzles are supplied with a liquid under high pressure. The liquid 18 is preferably water, without a restriction solely to water being seen therein.

[0043] In the embodiment of FIG. 1, the device 10 comprises a collection unit 22, which is arranged upstream of the rotor head 14 with respect to the movement direction X of the workpiece 12. Such a collection unit 22 is used for the purpose of receiving both scale, which has been removed from the surface 20 of the workpiece by means of the high-pressure liquid, and also the liquid, which rebounds therefrom after a contact with the surface 20 of the workpiece 12. In the illustration of FIG. 1, removed scale and the liquid rebounding from the surface 20 of the workpiece 10 are symbolized in simplified form by dot-dash lines.

[0044] In conjunction with the collection unit 22, a lower baffle plate 23.1 is provided, which is arranged between the rotor head 14 and the collection unit 22 and directly adjoins an open region of the collection unit 22 in this case. The lower baffle plate 23.1 is attached or fastened in this case on the collection unit 22 in such a way that its free end is positioned directly above the workpiece 12 and at the same time encloses an angle (FIG. 1) between 25-35 with the surface 20 of the workpiece. The lower baffle plate 23.1 is preferably attached in such a way that the angle in relation to the surface 20 of the workpiece 12 assumes a value of 30.

[0045] The lower baffle plate 23.1 is arranged flatly rising in the direction of the collection unit 22 in accordance with the angle of preferably 30. The lower baffle plate 23.1 therefore fulfills the task of a deflector plate and causes a targeted introduction of the scale and the liquid rebounding from the surface 20 into the collection unit 22.

[0046] In addition, a cover unit in the form of an upper cover plate 23.2 is provided, which extends from the collection unit 22 up to directly at the rotor head 14 and assumes the function of a cover in this case. The distance of an edge of the upper cover plate 23.2, which directly adjoins the rotor head 14, is selected in this case such that the section between the edge of the upper cover plate 23.2 and the rotor head 14 is passage-free with respect to scale particles. In the meaning of the present invention, passage-free means that scale particles, when they have been detached from the surface 20 of the workpiece 12 as a result of the sprayed water, cannot escape between the edge of the upper cover plate 23.2 directly adjoining the rotor head 14 and the rotor head 14. Accordingly, the upper cover plate 23.2 prevents scale or liquid rebounding from the surface 20 of the workpiece 12 from escaping upward to the surroundings. Nonetheless, it is ensured in this case that air can pass through the section between the upper cover plate 23.2 and the rotor head 14, and therefore stagnation pressure does not form below the upper cover plate 23.2 during the operation of the device 10 according to the invention.

[0047] Further relationships for the arrangement of the rotor head 14 and the jet nozzles 16 attached thereon are explained hereafter with reference to FIGS. 2 and 3.

[0048] The jet nozzles 16 are fixedly attached to an end face of the rotor head 14 opposite to the workpiece 12. In this case, the longitudinal axes L of the jet nozzles 16 are aligned parallel to the axis of rotation R of the rotor head 14. Accordingly, the spraying direction S (cf. FIG. 2), in which the liquid is sprayed out of the jet nozzles 16, also extends parallel to the axis of rotation R of the rotor head 14.

[0049] The axis of rotation R is arranged inclined diagonally at an angle (FIG. 2) with respect to an orthogonal on the surface 20 of the workpiece 12. An angle of attack (cf. FIG. 2), at which the liquid 18 sprayed out of the jet nozzles 16 is incident on the surface 20 of the workpiece, results due to the attachment of the jet nozzles 16 on the rotor head 14, in the case of which the longitudinal axis L of the jet nozzles extend parallel to the axis of rotation R, as explained. This angle of attack corresponds to an angle between the spraying direction S of the liquid 18 and an orthogonal on the surface 20 of the workpiece 12. Because of the parallel alignment of the longitudinal axis L of the jet nozzles 16 with the axis of rotation R, the angle of attack in the embodiment of FIG. 2 is equal to the inclination angle of the axis of rotation R.

[0050] The rotor head 14 is designed as vertically adjustable. This means that a distance A, which an intersection point of the axis of rotation R with the end face of the rotor head 14 has to the surface 20 of the workpiece 12 (FIG. 2) can be changed if needed. This distance A is to be understood as the spraying distance in the meaning of the present invention. If this distance A is reduced, the resulting impact pressure of the liquid 18 on the surface 20 of the workpiece 12 increases. The vertical adjustability for the rotor head 14 is symbolized in simplified form in FIG. 2 by the letter H and can be implemented by a vertically-adjustable mount, on which the rotor head 14 is attached. Details of an adjustment of this distance A are also explained in detail hereafter.

[0051] FIG. 3 illustrates a relationship between the spraying direction S, in which the liquid 18 is sprayed out of the jet nozzles 16, and the movement direction X, in which the workpiece 12 is moved past the device 10 and/or its rotor head 14. Specifically, FIG. 3 illustrates a projection of the spraying direction S in a plane parallel to the surface 20 of the workpiece 12. In the example of FIG. 3a, the spraying direction S, in which the liquid 18 is dispensed from a nozzle orifice 17 of a jet nozzle 16, is aligned precisely opposing the movement direction X, i.e., in a spraying angle of exactly 180 to the movement direction X. This has the result that the spraying direction S of the liquid 18, if it is permanently sprayed under high pressure onto the workpiece 12, does not have a fraction which points in the direction of a lateral edge of the workpiece 12. It is ensured in this way that the liquid 18 is always sprayed precisely in the direction of the collection unit 22 from the jet nozzles 16 onto the surface 20 of the workpiece. As a result thereof, the removed scale is introduced in conjunction with the liquid 18 rebounding from the surface 20 of the workpiece 12 in a targeted manner into the collection unit 22.

[0052] According to the examples of FIG. 3b and FIG. 3c, it is also possible that the spraying angle is greater or less than 180, for example, 170 or 190, or falls in a value range between 170 and 190. This means that the spraying direction S does not extend precisely opposing the movement direction X, but rather encloses an angle with the movement direction X whichas explained and illustrated in FIGS. 3b and 3ccan be in a range between 170 to 190.

[0053] It is noted separately at this point that the above-explained alignment of the spraying direction S, as shown in the illustrations according to FIG. 3a, FIG. 3b, and FIG. 3c, remains unchanged or constant during a rotation of the rotor head 14 about its axis of rotation R. This also applies for the angle of attack .

[0054] With respect to the rotor head 14 according to FIG. 2, it is to be noted that this rotor head 14 can correspond to that of FIG. 1. Notwithstanding this, it is also possible for the present invention to provide the rotor head 14 according to FIG. 2 without a collection unit 22.

[0055] A further embodiment of a device 10 according to the invention is shown in FIG. 4, specifically in a schematic, very simplified top view. In this case, two rotor heads 14.1 and 14.2 are arranged in succession with respect to the movement direction X of the workpiece 12. A separate collection unit 22, which is arranged upstream of an associated rotor head with respect to the movement direction X of the workpiece 12, is associated with each of these rotor heads 14.1 and 14.2. In principle, instead of the rotor head 14.2, another jet nozzle construction can also be provided.

[0056] The top view of FIG. 4 illustrates once again that the spraying direction S, in which the liquid 18 is dispensed from the jet nozzles 16 attached to a rotor head 14, does not have a fraction which points in the direction of a lateral edge 13 of the workpiece 12, but rather is instead oriented directly onto an associated collection unit 22.

[0057] Because of the reduced applied quantity of water according to the invention with improved effectiveness at the same time, the degree of soiling of the water with scale residues and/or corresponding solid particles is elevated, and therefore a different design of the collection unit is recommended.

[0058] The introduction of removed scale and liquid rebounding after a contact with the workpiece 12 from its surface 20 into a respective collection unit 22 is assisted as explained above by the lower baffle plate 23.1 rising flatly at the angle and is symbolized in FIG. 4 by the arrows E.

[0059] Further details of the collection unit 22 result from FIG. 5, which shows a cross-sectional view thereof.

[0060] A bottom surface 25 of the collection unit 22 is formed inclined laterally downward in each case. In the illustration of FIG. 5, the vertical symmetry line is aligned with a center of the workpiece 12. This has the result that the bottom surface 25 of the collection unit 22, starting from its center, drops down toward the lateral edges 24, and thus scale and liquid which are introduced into the collection unit 22 are also moved in the direction of the lateral edges 24.

[0061] The collection unit 22 is connected to a drainpipe 26, for example, at both lateral edges 24. Cleaning liquid and removed scale are discharged from the collection unit 22 through the drainpipe 26 as a result of gravity, for example, into a conveyor trough (not shown), into which the drainpipe 26 opens.

[0062] The discharge of cleaning liquid and scale from the collection unit 22, specifically through the drainpipe 26, can be optimized by a conveyor unit 27, by means of which the cleaning liquid and scale inside the collection unit are conveyed in the direction of an opening of the drainpipe 26 and/or in the direction of the lateral edges 24. For this purpose, the conveyor unit 27 comprises, for example, flushing nozzles 28 (FIG. 5), from which a fluid, for example, a liquid or a gas or a mixture thereof, is discharged diagonally to the bottom surface 25. Alternatively or additionally to such flushing nozzles 28, it is also possible that the conveyor unit 27 has mechanical components, for example, scraper elements, conveyor screws, or the like, by means of which the liquid and/or the scale are conveyed in a targeted manner in the direction of an opening of the drainpipe 26.

[0063] Possible embodiments of rotor heads, which can be used, for example, in the embodiment of FIG. 4, are shown and explained hereafter with reference to FIGS. 6 and 7.

[0064] FIG. 6 shows a side view of a rotor head pair 29, in which one rotor head 14 is provided in each case above and below the workpiece 12, i.e., both on its upper side and on its lower side. It can be seen that the rotor head 14 which is arranged below the workpiece 12 is positioned upstream with respect to the movement direction X of the workpiece 12 from the rotor head 14 which is arranged above the workpiece 12. This is because liquid 18 which is sprayed from the jet nozzles 16 of the rotor head 14 arranged below the workpiece 12 thus does not, for example, strike against the rotor head 14 arranged above the workpiece 12 if no workpiece or strip material should be located between these two rotor heads. The offset shown in FIG. 6 between the rotor heads arranged above and below the workpiece 12 does not change the fact that these two rotor heads are to be understood as a rotor head pair 29 in the meaning of the present invention. In this regard, it is apparent that the reference signs 14.1 and 14.2 shown in FIG. 4 can respectively also be such a rotor head pair.

[0065] FIG. 7 shows a frontal view of rotor head modules 30, which are provided in each case above and below the workpiece 12 and thus form a rotor module pair 31. Specifically, the respective rotor head modules 30 consist of a plurality of rotor heads 14, which are arranged adjacent to one another and transversely to the movement direction X of the workpiece. Notwithstanding the illustration in FIG. 7, fewer or more than three rotor heads 14 can also be combined to form a rotor module 30.

[0066] For the illustration of FIG. 6, it is additionally to be noted that this can also be a side view of a rotor module pair 31 according to FIG. 7, wherein in each case only the rotor head 14 lying in front in the plane of the paper can be seen at the upper and lower sides of the workpiece.

[0067] With respect to the embodiments according to FIGS. 6 and 7, it is to be noted that the individual rotor heads 14 are connected to a common pressurized water line D, wherein the pressurized water line D is connected to the high-pressure pump unit. A supply of the jet nozzles 16 attached to the rotor heads with high-pressure water is ensured in this way.

[0068] In the embodiment according to FIG. 4, notwithstanding the illustration shown, it can also be provided that instead of the individual rotor heads 14.1 and 14.2, which are arranged in succession with respect to the movement direction X, rotor modules 30 are also provided, specificallybecause of the arrangement above and below the workpiece 12in the form of rotor module pairs 31 according to FIG. 7.

[0069] In the case of a rotor module 30 according to the embodiment of FIG. 7, the width of a workpiece 12, i.e., in a direction transverse to its movement direction X, is covered as shown by a plurality of rotor heads 14. In other words, the width of such a rotor module 30 substantially corresponds to a width of the workpiece 12. This results in the advantage that in contrast to, for example, only a single rotor head, the diameter of which corresponds to the width of the workpiece 12, the diameter of the individual rotor heads of a rotor module 3 can be smaller in each case, linked to the advantage that higher speeds are settable for these rotor heads, possibly also to adapt to high rolling velocities and/or high feed velocities for the workpiece.

[0070] It is advantageous if the individual rotors of a rotor module can be depressurized individually and/or in groups and thus the dispensing of the liquid is adapted to the width of the workpiece.

[0071] FIG. 8 symbolizes an attachment of multiple jet nozzles 16 to an end face of a rotor head 14. In the example of FIG. 8, three jet nozzles 16.1, 16.2, and 16.3 are provided, which each have a different distance s to the axis of rotation R of the rotor head 14. In the illustration of FIG. 8, the axes of rotation R extends perpendicularly to the plane of the drawing.

[0072] The different distances of the respective jet nozzles 16.1, 16.2, and 16.3 are respectively identified in FIG. 8 with s.sub.1, s.sub.2, and s.sub.3, with the proviso: s.sub.1>s.sub.2>s.sub.3. With such an arrangement of jet nozzles each having different radial distance from the axis of rotation R, it is provided that a greater volume flow of liquid is sprayed out of a jet nozzle which has a greater radial distance to the axis of rotation R than in comparison to a jet nozzle which has a smaller distance to the axis of rotation. The relationship: {dot over (V)}.sub.1>{dot over (V)}.sub.2>{dot over (V)}.sub.3 then applies for the volume flow dispensed from these nozzles with respect to the three nozzles 16.1, 16.2, and 16.3 according to FIG. 8. In this way, a more uniform energy introduction onto the surface 20 of the workpiece 12 transversely to its movement direction X is achieved for the liquid dispensed from the jet nozzles 16.1, 16.2, and 16.3.

[0073] The relationships just explained with reference to the illustration of FIG. 8 are also understood for a number of jet nozzles of greater or less than three, specifically in any case for multiple jet nozzles which each have a different distance to the axis of rotation R of the rotor head 14. Furthermore, it is to be noted that the example of FIG. 8 also applies for all rotor heads 14 which are shown and explained in FIGS. 1-7.

[0074] A scale detection unit 32 can be provided for the invention, which is arranged downstream from a rotor head 14 or a rotor head pair 29 or a rotor module pair, respectively, with respect to the movement direction X of the workpiece 12, wherein reference is made hereafter to a rotor head 14 for simplification, without a restriction being seen therein. In the embodiment of FIG. 4, such a scale detection unit 32 is arranged downstream of the rotor head 14.2. Notwithstanding the number of rotor heads which can be arranged in succession in relation to the movement direction X of the workpiece 12 in the present invention, it is significant for the scale detection unit 32 that it is arranged in the spatial vicinity and downstream of a rotor head (for example, rotor head 14.2 according to FIG. 4) of the device 10, in any case before the workpiece 12 is subjected, for example, to a further rolling procedure.

[0075] The scale detection unit 32 is connected for signaling to a control unit 34 (FIG. 1, FIG. 4). It is possible by means of the scale detection unit 32 to reliably recognize and/or detect residual scale possibly remaining on the surface 20 of the workpiece 12, after the liquid 18 has been sprayed on the workpiece 12. For this purpose, the scale detection unit 32 extends completely over a width of the workpiece 12. Furthermore, it is to be noted that a scale detection unit 32 can be provided above and below the workpiece 12, i.e., on its upper side and on its lower side. It is accordingly possible by means of the scale detection unit 32 to detect possible residual scale on both surfaces of the workpiece 12.

[0076] The illustrations of FIG. 1 and FIG. 4 symbolically show that a rotor head 14 is also connected for signaling to the control unit 34. This means that it is possible by means of the control unit 34 to change the pressure with which the liquid sprayed out of the jet nozzles 16 strikes on a surface 20 of the workpiece 20 in a suitable manner. Such a change of the impact pressure of the liquid can be performed, for example, by switching on or off a pump of the high-pressure pump unit, to which the pressurized water line D for the jet nozzles 16 is connected. Additionally or alternatively, it can be provided that the high-pressure pump unit, using which the pressure supply for the jet nozzles 16 is ensured, is equipped with a frequency controller, to achieve still better adaptation of the desired pressure for the jet nozzles 16.

[0077] Alternatively and notwithstanding the provision of a scale detection unit 32, it is possible for the present invention that a rotor head 14 is connected for signaling to the control unit 34. The speed with which the rotor head 14 is rotated about its axis of rotation R can accordingly also be adapted by means of the control unit 34, for example, in dependence on the feed velocity at which the workpiece is moved past the device 10 in its movement direction X, for example. By means of such an adaptation of the speed for the rotor head 14, in particular to the feed velocity of the workpiece 12 in its movement direction X, an optimum energy introduction for the liquid 18 sprayed onto the surface 20 of the workpiece 12 is achieved, specifically along the movement direction X. Such an optimum adaptation of the speed of the rotor head 14 to the feed velocity of the workpiece 12 is shown in the spraying picture according to FIG. 9a, which shows a portion of a surface 20 of the workpiece 12 in a top view. In contrast, the illustration of FIG. 9b illustrates a nonoptimal adaptation of the speed of the rotor head 14 to the feed velocity of the workpiece 12. It is possible by means of the invention to avoid a spray picture according to the illustration of FIG. 9b.

[0078] The invention functions as follows:

[0079] For a desired descaling of the surfaces 20 of a workpiece 12, this workpiece is in motion in relation to the device 10 according to the invention in a movement direction X. For this purpose, rotor heads 14 of the device 10 are preferably provided both on a top side and also on a bottom side of the workpiece 12, according to the embodiment of FIG. 6. A descaling of the workpiece 12 is achieved in that a liquid 18 is sprayed from the jet nozzles 16 attached to a rotor head 14 under high pressure onto the surfaces 20 of the workpiece 12. As a result of the above-explained alignment of the jet nozzles 16 and the spraying direction S for the liquid 18 resulting therefrom, removed scale, in conjunction with the liquid rebounding from the surface 20 of the workpiece 12, is introduced in a targeted manner into the collection unit 22.

[0080] Means (not shown) are provided, by way of which the control unit 34 receives an item of information with respect to the feed velocity of the workpiece 12 in its movement direction X. Based thereon, a desired speed for a rotor head 14 can be set by means of the control unit 34, specifically in adaptation to the feed velocity of the workpiece 12. Such an adaptation is also possible in the running production mode, if variations occur in the feed velocity for the workpiece 12. The control unit 34 can be configured by programming in such a way that such an adaptation of the speed of a rotor head 14 also takes place in a regulated manner.

[0081] On the basis of the signals of the scale detection unit 32, the pressure with which the jet nozzles 16 attached to a rotor head 14 are supplied with the liquid 18 can be set and/or adapted to a predetermined value. This means that the pressure of the liquid 18 provided for the jet nozzles 16 is set just high enough, for example, that a sufficient descaling quality is achieved, which can then be monitored by means of the scale detection unit 32. In this way, a savings of the quantity of water and energy is possible. In contrast, if it should be recognized by the control unit 34, on the basis of the signals generated by the scale detection unit 32, that the descaling quality falls below a defined setpoint value, this can be compensated for by a suitable pressure increase, by switching on a pump and/or by switching on an additional descaling unit, for example, in the form of a rotor head pair 29 or a rotor module pair 31. Such an operating sequence according to the present invention is also illustrated in the flow chart of FIG. 11.

[0082] Additionally and/or alternatively, the change of the impact pressure can be performed by a vertical adjustment of the rotor head arrangement. This vertical adjustment is symbolized in FIG. 2, as already explained therein, by the arrow H. In this case, the distance A (FIG. 2), which a rotor head 14 has from the surface 20 of the workpiece 12, can be adjusted and/or changed in dependence on the signal values of the scale detection unit 32. For example, this distance A can be reduced if the descaling quality of the surface 20 of the workpiece 12 is judged to be unsatisfactory, wherein the impact pressure of the liquid 18 on the surface 20 of the workpiece 12 increases as a result of the reduced distance A. Conversely, this means that the distance A can also be increased, in any case as long as the descaling quality remains sufficiently high and a predetermined setpoint value for this purpose is achieved.

[0083] To carry out the present invention, it is advisable in the production of the device 10 according to the invention to select the inclination of the rotor head (cf. angle in FIG. 2) and the attachment of the jet nozzles 16 to the rotor head such that the angle of attack is in a range from 5 to 25 and preferably assumes a value of 15.

[0084] Finally, it is to be noted that a rotor head 14.3 according to the illustration of FIG. 11 and/or a rotor head 14.4 according to the illustration in FIG. 12 can also be used for the present invention.

[0085] In the rotor head 14.3 according to FIG. 11, its axis of rotation R extends perpendicularly to the surface 20 of the workpiece 12 to be descaled, wherein the jet nozzles 16 are attached inclined on an end face of the rotor head 14.3. During a rotation of the rotor head 14.3 about its axis of rotation R, the jet nozzles 16 are rotated simultaneously and synchronously about the longitudinal axis L thereof such that at the same time the angle of attack in relation to the surface 20 remains constant in each case. This is achieved via a planetary gear 36, which is integrated into the rotor head 14.3.

[0086] In the rotor head 14.4 according to FIG. 12, the axis of rotation R also extends perpendicularly to the surface 20 of the workpiece 12, wherein the jet nozzles 16 are attached to the rotor head 14.4 with the longitudinal axis L thereof parallel to the axis of rotation R. The jet nozzles 16 have a suitably formed outlet opening at the respective nozzle orifice 17 thereof, by which a deflection of the sprayed liquid 18 is achieved, whereby the angle of attack shown in FIG. 13 results. This angle of attack thus remains constant during a rotation of the rotor head 14.4 about its axis of rotation, by the jet nozzles 16 each being rotated about the longitudinal axis L thereof by means of a planetary gear synchronously to the rotation of the rotor head 14.4.

[0087] It is apparent that the rotor heads 14.3 and/or 14.4 can also be used like a rotor head pair 29 and/or like a rotor module pair 31 according to the illustrations in FIG. 6 and in FIG. 7, respectively.

[0088] If the rotor heads 14.3 and 14.4 are used, the same spraying direction S can be achieved for the sprayed liquid 18 as shown in the illustration of FIG. 3a. Alternatively thereto, it is also possible if a rotor head 14.3 or 14.4 is used to set a spraying direction S for at least one jet nozzle attached to such a rotor head, such that the resulting spraying direction S encloses an angle with the movement direction X of 170 (FIG. 3b) or 190 (FIG. 3c), or an angle which respectively lies between 170-180 or 180-190.

[0089] It is possible, for example, that the rotor head shown in FIG. 8 is a rotor head according to FIG. 11 or FIG. 12. In this case, it can then be provided that the spraying direction S of the jet nozzle 16.2 is aligned at a spraying angle of 180 (FIG. 3a), wherein the spraying direction S of the jet nozzle 16.1 is aligned at a spraying angle of 170 (FIG. 3b) and the spraying direction S of the jet nozzle 16.3 is aligned at a spraying angle of 190 (FIG. 3c). By way of such an arrangement of jet nozzles on a rotor head, it is possible to further enhance the descaling quality for the workpiece 12, because possible depressions which can form on the surface 20 of the workpiece hereby also experience effective descaling by avoiding spray shadows.

[0090] Moreover, it is to be noted that the rotor heads 14.3 and 14.4 according to FIG. 11 and FIG. 12, respectively, can be used in the same manner as the rotor head 14 (FIG. 2) in the embodiments according to FIG. 1 or FIG. 4. The mode of operation for descaling the workpiece 12 remains unchanged in this case, and therefore reference can be made to the above explanations to avoid repetitions.

LIST OF REFERENCE SIGNS

[0091] 10 device [0092] 12 workpiece [0093] 14 rotor head [0094] 16 jet nozzle [0095] 16.1 jet nozzle [0096] 16.2 jet nozzle [0097] 16.3 jet nozzle [0098] 18 liquid [0099] 20 surface [0100] 22 collection direction [0101] 23.1 cover unit [0102] 23.2 cover unit [0103] 26 drainpipe [0104] 27 conveyor unit [0105] 28 flushing nozzle [0106] 29 rotor head pair [0107] 31 rotor module pair [0108] 32 scale detection unit [0109] angle of attack [0110] spraying angle [0111] angle [0112] L longitudinal axis [0113] R axis of rotation [0114] S spraying direction [0115] V.sub.1 volume flow [0116] V.sub.2 volume flow [0117] V.sub.3 volume flow [0118] X movement direction