Title of Invention

AN APPARATUS FOR DESCALING HOT ROLLED STOCK

Abstract The invention relates to a device which is used to descale warm rolling products (17) which can be displaced in relation to the device by high pressure water projection. Said device comprises at least one row of nozzle heads which cover the width of the rolling products, said row of nozzle heads comprising several nozzle heads (20). Each nozzle head is driven in a rotational manner by a motor about a rotational axis (A) which is essentially perpendicular to the surface to the rolling products and comprises at least two nozzles (1 8) which are disposed in an eccentric manner in relation to the rotational axis. The invention is characterised in that the nozzles (1 -8) of each nozzle head (20) are arranged as close as constructively possible on the periphery (25) of the nozzle head in such a manner that the nozzle head produces an injection image on the surface of the rolling product, said injection image at least touching the injection image of the nozzle head which is next in the row of nozzle heads.
Full Text PCT/EP2004/001968
An apparatus for descaling hot rolled stock.
The invention relates to an apparatus for descaling hot rolled stock, being moved with respect to the apparatus, by spraying it with high pressure water, comprising at least one row of nozzle heads sweeping across-the width of the rolled stock with a plurality of nozzle heads, each nozzle head being motor-driven in rotation about an axis of rotation substantially perpendicular to the surface of the rolled stock and comprising at least two nozzles which are disposed eccentrically with respect to the axis of rotation.
For uniform treatment of the rolled stock surface by means of an apparatus of this kind known from DE 43 28 303 the nozzles in each nozzle head are disposed at different angles with respect to the axis of rotation so that the spray pattern of each nozzle with reference to the axis of rotation of the nozzle head covers a different radial area. Hereby it is intended that the rolled stock surface subjected to treatment by a nozzle head be descaled uniformly throughout the full radius of the nozzle head.
DE 43 28 303 is silent as to how such uniform descaling is to be achieved in the direction of the width of the rolled stock surface. To obtain uniform spraying intensity, the distance between the nozzles and the rolled stock to be sprayed on as well as the angle of inclination of the nozzles with respect to the line perpendicular to the surface of the rolled stock and also the jet opening angle of the spray cone must be kept as small as possible. On the other hand, a respective minimum spacing must be observed between adjacent nozzle heads of the row of nozzle heads in width direction of the rolled stock. Therefore, when a. nozzle head row is positioned transversely of the direction of movement of the rolled stock, it is possible for stripes to remain on the surface between adjacent nozzle heads where insufficient or no descaling was achieved.

2
It is an object .of the invention to overcome such shortcoming by providing a descaling apparatus of the kind specified initially which permits uniform descaling of rolled stock across the entire width thereof.
The features defined in claim 1 serve to meet that object.
With the invention, the arrangement and inclination of the nozzles of each nozzle head are designed in response both to the distance of the nozzle heads from the rolled stock surface and the spacing between adjacent nozzle heads such that each nozzle head creates a spray pattern on the surface of the rolled stock . which pattern at least will touch, or better still overlap, the spray pattern of the adjacent nozzle head or heads in the row of nozzle heads. Thus it is warranted that, when directing jets onto the surface of rolled stock, no surface stripes will result where no descaling or only insufficient descaling took place.
In a preferred embodiment of the apparatus according to the invention the nozzles of each nozzle head are inclined radially ¦ outwardly.
In an especially preferred embodiment the nozzles additionally are inclined in circumferential direction in the sense of rotation, i.e. so as to be leading with respect to the rotary movement of the nozzle head.
When the nozzle heads of a row of nozzle heads are driven in the same direction this will result in the nozzle jets rotating past each other in mirror image opposite directions in the zone of the gap between two nozzle heads. That may have the undesirable consequence of the nozzle jets mutually influencing each other, thus causing turbulences which are detrimental to the desired uniform descaling. For this reason, it is another object of the invention to overcome that. To this end it is provided that, m

3
an apparatus of the kind specified initially, adjacent nozzle heads in the row of nozzle heads are adapted to be driven so as to rotate in opposite sense. This concept is important both in combination with the features of claim 1 and also with the features of the preamble alone of claim 1.
Further advantageous modifications of the invention are indicated in the other subclaims, e.g. preferred angular ranges of the radial inclination of the nozzles and of the inclination of the nozzles in circumferential direction, as well as preferred numbers.of nozzles distributed evenly around the circumference of each nozzle head.
The invention will be described in greater detail below with reference to diagrammatic drawings, in which:
Fig. 1 is a diagrammatic perspective view of a known apparatus;
Fig. 2 shows a nozzle head of the known.apparatus and a spray pattern produced by the nozzles thereof;
Fig. 3^ shows a known nozzle and a spray pattern produced by
the same; Fig. 4 is a diagrammatic illustration of two nozzle heads
according to the invention arranged side by side in a
row.of nozzle heads above the rolled stock; and Fig. 5 is a view of the two nozzle heads as seen in the
direction of arrow V in fig. 4.
The apparatus for descaling rolled stock It shown in fig. 1 comprises two rows 18, each including five stationary nozzle heads 20 and extending transversely of the direction of movement F the rolled stocK 17, at either side thereof. One of those
o, le heads is shown in detail in rig. 2. at its circumference, each nozzle head 20 is provided with four flat-sectron jet nozzles 21 distributed around the circumference and mounted on a ring of the nozzle head 20 which ring is adapted to be driven

4
in rotation. The nozzles are supplied through conduits 9 with" -pressurized water at a pressure of from 300 to 1000 bar.
The ring 22 is driven at a number of revolutions of from 200 to 1000 r.p.m.
The nozzle heads 20 are arranged with a distance a of the nozzles 21 from the surface of the rolled stock which is moving in the direction of arrow F under the stationary row of nozzle heads. This distance is selected so that the length t of the great major axis and the length s of the small major axis of the elliptical spray pattern of each nozzle 21, as shown in fig. 3, correspond to desired values. The opening angle of the flat-section jet lies between 0° and 15° .
The ellipse 10, pressed flat in the spray pattern shown in fig. 2, rotates about the vertical axis of rotation A of the nozzle head 20 due to the rotation of the nozzles 21 while the rolled, stock 17, at the same time, is advanced in the direction of arrow F under the nozzle heads 20. At a rotational speed of 1000 r.p.m. and a travelling speed v of 0.8. m/sec of the rolled stock with respect to the stationary nozzle heads 20, the rolled stock advances by distance d with each revolution of the nozzle head 20. This distance d corresponds to one fourth to one fifth of the radius of the nozzle head. In this manner an overall spiral shaped spray pattern is obtained, as illustrated in fig. 2.
If the spray cones 28 of adjacent nozzle heads 20 do not touch or overlap each other sufficiently in the zones between the nozzle heads it may happen that surface stripes 29 remain on the surface of the rolled stock where descaling did not take place or not sufficiently so. This stands in the way of achieving the desired uniform surface quality of the rolled stock across the entire width thereof.

5
Figs. 4 and 5 are diagrammatic presentations of two adjacent nozzle heads of a row of nozzle heads in accordance with the invention. Each nozzle head comprises a total of eight nozzles.1 to 8 uniformly distributed around the circumference. The openings of the nozzles at the bottom of the nozzle head 20 are arranged radially as far as possible towards the outside, in other words as closely as structurally possible to the outermost circumference 25 of each nozzle head. The eight nozzles 1. to 8 . are aligned along nozzle axes la to 8a.
As may be taken from fig. 4, these nozzle axes la to 8a are ' inclined radially outwardly at an angle a and, furthermore, are inclined at an angle ft in circumferential direction in the sense of rotation, i.e. so as to be leading in the direction of rotation f or f of the nozzle heads. This results in an overall inclination of each nozzle both in radial and circumferential directions by angles a and b. The angle a lies in the range between 0° and.20°, preferably in the range of a = 12° ± 2°.
The angle li lies in the range between 0° and 30°, preferably in the range between ft = 15°-± 2°.
Fig. 4 also shows that, with a distance a,-between the bottom 26 of the nozzle heads '20 and the surface 27 to be descaled of the rolled stock, the outer generated surfaces of the spray cones, indicated in discontinuous lines in fig. 4, just barely touch each other at point P of nozzles 7, 7 in the gap b between the two adjacent nozzle heads, in other words at the minimum spacing between them. Thus the full width of the rolled stock surface is covered by the nozzle jets, and no stripes 29 (fig. 1) are left where the surface has not been descaled or only insufficiently so.
A desired overlap of the nozzle jets exiting from the nozzles 7, to make sure the formation of stripes described above is totally eliminated, readily could be achieved by reducing the distance a

6
and/or increasing the radial angle of inclination a and/or increasing the jet opening angle s.
In the embodiment shown, adjacent nozzle heads 20 rotate in opposite directions. This means that in the gap b between two adjacent nozzle heads 20 the .jets exiting from the nozzles, thereof each are sprayed in mirror image in the same direction. For example, nozzles 7, 7 in fig. 5 spray in mirror image obliquely upwardly. This is advantageous with a view" to achieving a uniform surface quality. Moreover, the torques of adjacent nozzle heads are compensated by the fact that the nozzle heads are driven in pairs in opposite directions.
The number of rows of nozzle heads may be even or uneven. The
number will be greater or smaller, depending on the width of the
rolled stock to be descaled. Where rolled stock of different
widths must be descaled in a rolling mill installation, it is
advantageous to have the nozzle heads 20 designed for switch-off
and on in pairs or groups.
The features disclosed in the specification above, in the figures
and claims may be significant for implementing the invention in
its various modifications, both individually and in any
combination.

PCT/EP2004/001968
Amended Claims (to be used for filing in your country)
1. An apparatus for descaling hot rolled stock, being moved
- with respect to the apparatus, by spraying it with high
pressure water, comprising at least one row of nozzle heads sweeping across the width of the rolled stock with a plurality of nozzle heads (20), each nozzle head being motor-driven in rotation about an axis of rotation (A) substantially perpendicular to the surface (27) of the rolled stock and comprising at least two nozzles (1 to 8) which are disposed eccentrically with respect to the axis of rotation (A), the nozzles (l.to 8) of each nozzle head (20) being arranged as closely as structurally possible to the circumference (25) of the nozzle head, whereby a spray pattern is created on the surface (27) of the rolled stock in a way to touch or overlap the spray pattern of the adjacent nozzle head (20) in the row of nozzle heads,.and the nozzles (1 to 8) being arranged in the nozzle head (20) radially inclined outwardly at an angle of inclination {a) in the range of 0° 2. The apparatus according to claim 1, characterized in that
the angle (a) of radial inclination is in the range of a ~ 12°
± 2 ° .
3. The apparatus as claimed in claim 1 or 2., characterized
in that the angle of inclination (ft) of the nozzles in circum
ferential direction lies in an angular range of 0° especially in the angular range of ft «= 15° ±2°.
4. The apparatus according to one of claims 1 to 3,
characterized in that adjacent nozzle heads (.20, 20) in the
row of nozzle heads are driven in counter-rotating sense.
5. The apparatus as claimed in- any one of claims 1 to 4,
characterized in that the jet opening angle (e) of the jet

exiting from the nozzles (1 to 8) is no greater than 15°, especially no greater than 10°'.
6. The apparatus as claimed in any one of claims 1. to 5,
characterized in that at least six nozzles are arranged evenly
distributed around the circumference of each nozzle head.
7. The apparatus as claimed in claim 6, characterized in
that eight nozzles (1 to 8) are arranged evenly distributed
around the circumference of each nozzle head (20).
8. The apparatus as claimed in any one of claims 1 to 7,
characterized in that pairs or groups of nozzle heads in the
row of nozzle heads are adapted to be switched off or on in.
correspondence with different widths of rolled stock.

Documents:

02352-kolnp-2006-abstract.pdf

02352-kolnp-2006-claims.pdf

02352-kolnp-2006-correspondence others-1.1.pdf

02352-kolnp-2006-correspondence others.pdf

02352-kolnp-2006-description(complete).pdf

02352-kolnp-2006-drawings.pdf

02352-kolnp-2006-form-1-1.1.pdf

02352-kolnp-2006-form-1.pdf

02352-kolnp-2006-form-2.pdf

02352-kolnp-2006-form-26.pdf

02352-kolnp-2006-form-3.pdf

02352-kolnp-2006-form-5.pdf

02352-kolnp-2006-international publication.pdf

02352-kolnp-2006-international search authority report-1.1.pdf

02352-kolnp-2006-international search authority report.pdf

02352-kolnp-2006-other pct form.pdf

02352-kolnp-2006-others.pdf

02352-kolnp-2006-pct form.pdf

02352-kolnp-2006-pct others.pdf

02352-kolnp-2006-priority document.pdf

2352-KOLNP-2006-(11-04-2012)-PETITION UNDER RULE 137.pdf

2352-KOLNP-2006-(23-02-2012)-ABSTRACT.pdf

2352-KOLNP-2006-(23-02-2012)-AMANDED CLAIMS.pdf

2352-KOLNP-2006-(23-02-2012)-DESCRIPTION (COMPLETE).pdf

2352-KOLNP-2006-(23-02-2012)-DRAWINGS.pdf

2352-KOLNP-2006-(23-02-2012)-EXAMINATION REPORT REPLY RECEIVED.pdf

2352-KOLNP-2006-(23-02-2012)-FORM-1.pdf

2352-KOLNP-2006-(23-02-2012)-FORM-2.pdf

2352-KOLNP-2006-(23-02-2012)-FORM-3.pdf

2352-KOLNP-2006-(23-02-2012)-OTHERS.pdf

2352-KOLNP-2006-CORRESPONDENCE.pdf

2352-KOLNP-2006-EXAMINATION REPORT.pdf

2352-KOLNP-2006-FORM 18 1.1.pdf

2352-kolnp-2006-form 18.pdf

2352-KOLNP-2006-FORM 26.pdf

2352-KOLNP-2006-FORM 3.pdf

2352-KOLNP-2006-FORM 5.pdf

2352-KOLNP-2006-GRANTED-ABSTRACT.pdf

2352-KOLNP-2006-GRANTED-CLAIMS.pdf

2352-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

2352-KOLNP-2006-GRANTED-DRAWINGS.pdf

2352-KOLNP-2006-GRANTED-FORM 1.pdf

2352-KOLNP-2006-GRANTED-FORM 2.pdf

2352-KOLNP-2006-GRANTED-LETTER PATENT.pdf

2352-KOLNP-2006-GRANTED-SPECIFICATION.pdf

2352-KOLNP-2006-OTHERS.pdf

2352-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

abstract-02352-kolnp-2006.jpg


Patent Number 253499
Indian Patent Application Number 2352/KOLNP/2006
PG Journal Number 30/2012
Publication Date 27-Jul-2012
Grant Date 25-Jul-2012
Date of Filing 21-Aug-2006
Name of Patentee HERMETIK HYDRAULIK AB
Applicant Address LANSENVAGEN 3, 18762 TABY SWEDEN, SWEDEN
Inventors:
# Inventor's Name Inventor's Address
1 GAYDOUL, JURGEN LANSENVAGEN 3, 18762 TABY SWEDEN, SWEDEN
PCT International Classification Number B21B 45/08
PCT International Application Number PCT/EP2004/001968
PCT International Filing date 2004-02-27
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA 2004-02-27 Sweden