EP1131170B1 - Method and device for reducing the formation of scales on rolling stock - Google Patents

Abstract

The invention relates to a method and a device for reducing the formation of scales on rolling stock (3) which leaves the roll stand. According to the invention, heated water, especially wet steam, is sprayed onto the rolling stock (3) when it leaves the roll stand. Said heated water, especially the wet steam, is sprayed onto the rolling stock (3) from a main direction component of spraying which is not perpendicular to the surface of the rolling stock (3).

Description

The invention relates to a method and a device for Reduction of scale formation on a rolling stock made from a Roll stand runs out.

When rolling rolled material, especially in the cooling process, comes it for scale formation. This applies in particular to cooling of rolling stock with water. Scale formation affects the surface quality of the rolling stock, in particular steel, in in some cases considerably.

From DE-A-44 30 856 a method is known in which Reduction of scale formation in the rolling stock with a droplet mist is encased in water.

The object of the invention is one Improvement of such a method, especially in With a view to further reducing the formation of new Tinder and removing any existing tinder, as well the provision of a device for performing this Process.

According to the invention, the object is achieved by a method or a method Device according to claim 1 or claim 11 solved. there is used to reduce scale formation on a rolling stock, that runs out of a rolling stand, the rolling stock after the Roll stand with heated water, especially with wet steam, sprayed, the heated water, especially the wet steam, with one from the vertical of the surface of the rolling stock different main spray direction component on the Rolled stock is sprayed. In this way the formation of Scale significantly reduced, or existing scale when it runs out of the rolling stock removed (in part) from the rolling stand. In addition, it has been shown that the rolling stock in this way can be cooled significantly faster, Permitted use of a shorter cooling section and another the quality of the rolling stock increases.

Spraying a rolling stock with heated water or wet steam is already known from DE-A-196 37 916. It will used there only for cooling and the Spray direction is directed vertically against the rolling stock.

In an advantageous embodiment of the invention, the heated Water, especially wet steam, at a main spray direction angle from 15 ° to 45 °, advantageously 15 ° to 30 °, sprayed on the rolling stock.

In a particularly advantageous embodiment, the heated Water, especially wet steam, with one on at least one Outer edge of the rolling stock aligned main spray direction component sprayed on the rolling stock. In this way, one particularly good reduction of scale formation achieved.

In a further advantageous embodiment of the invention the heated water, especially wet steam, with a main spray direction component in the direction of the rolling stock the rolling stock is sprayed.

In a further advantageous embodiment of the invention the rolling stock is sprayed with coolant from above and below. In this way it is possible to build up the scale reduce both sides of the rolling stock and the rolling stock particularly cool down quickly.

In a further advantageous embodiment of the invention the rolling stock with water, the temperature of which is between 50 ° C. and the boiling point is sprayed. An even cheaper temperature range for the heated water the range is between 80 ° C and the boiling point, which in turn results from this Range the range between 90 ° C and 99 ° C as special has proven advantageous. Water from this temperature range vaporizes particularly quickly when it hits the are called rolling stock. In a particularly advantageous embodiment The invention makes the water special in shape small droplets, especially in the form of spray, against the rolling stock is sprayed. This use of hot wet steam or hot spray has been associated with the invention as particularly advantageous for reducing scale formation or to remove scale.

In a further advantageous embodiment of the invention is the cooling water or wet steam at a relatively high pressure sprayed against the rolling stock.

In a further advantageous embodiment of the invention deoxidation gases, especially carbon monoxide, are added to the cooling water or hydrogen, admixed, which causes scaling is counteracted. It is also advantageous that Add coolant tinder.

FIG 1

eine Kühleinrichtung zum Kühlen von Walzgut,

FIG 2

eine Kühleinrichtung zum Kühlen von Walzgut mit zweiseitiger Kühlung,

FIG 3

eine Ausgestaltung der Erfindung,

FIG 4

eine weitere beispielhafte Ausgestaltung der Erfindung,

FIG 5

eine Kühleinrichtung zum Kühlen von Walzgut.

Further advantages and inventive details emerge from the following description of exemplary embodiments, using the drawing and in conjunction with the subclaims. In detail show:

FIG. 1

a cooling device for cooling rolling stock,

FIG 2

a cooling device for cooling rolling stock with double-sided cooling,

FIG 3

an embodiment of the invention,

FIG 4

another exemplary embodiment of the invention,

FIG 5

a cooling device for cooling rolling stock.

1 shows a rolling stock 3, in particular steel, as it exits from the last scaffolding of a hot rolling mill, indicated by the rollers 1 and 2. The rolling stock 3 is after leaving the last roll stand cooled by a cooling device. The Cooling device has coolant lines 4, 41, 42, 43 Nozzles 31, 45, 46, 47 from which coolants 5, 51, 52, 53 is sprayed onto the rolling stock 3. The coolant 5, 51, 52, 53 is heated water or wet steam. There is a temperature range for the heated water from 80 to 99 ° C, in particular proven from 90 to 99 ° C. The coolant 5, 51, 52, 53 is advantageously in the form of high pressure small droplets, such as spray, are sprayed against the rolling stock.

2 shows a rolling stock 3 as it emerges from the last stand a hot rolling mill, indicated by rolls 1 and 2. The rolled stock 3 is after exiting the last rolling stand cooled by a cooling device. The cooler has coolant lines 4, 41, 42, 43 and 6, 61, 62, 63 with Nozzles 21, 45, 46, 47 and 64, 65, 66, 67 on, from which coolant 5, 51, 52, 53 and 7, 71, 72, 73 sprayed onto the rolling stock 3 becomes. The coolant 5, 51, 52, 53 and 7, 71, 72, 73 is advantageously heated water or wet steam. there has a temperature range for the heated water of 80 up to 99 ° C, in particular from 90 to 99 ° C particularly proven. The coolant 5, 51, 52, 53 and 7, 71, 72, 73 is advantageously with high pressure in the form of small droplets, such as about spray mist, sprayed against the rolling stock 3. Details of the Cooling with devices as shown in FIGS. 1 and 2, can be found in DE 196 37 916.

3 shows a side view of the device according to FIG. 1. The coolant line has 4 inclined nozzles 31, 32, 33, 34. The nozzles 31 and 32 have a main spray angle α from -20 ° to. That is, the main spray direction the coolant 5, 55 which exits from the nozzles 31 and 32, is at an angle α = 20 ° to the vertical of the surface of the rolling stock 3 inclined. For the nozzles 33 and 34 and the corresponding jets of coolant 56 and 57 apply accordingly, this having a main spray angle α of 20 ° exhibit. In this way, the nozzles 31, 32, 33, 34 spray with a main spray direction component to the respective Outer edges of the rolling stock 3.

In an advantageous embodiment of the invention, the Main spray direction also in the running direction 38 of the rolling stock 3 from the vertical of the surface of the rolling stock 3. A Such an embodiment is shown in FIG. 4. Here is the coolant line 4 replaced by a coolant line 35. The Coolant line 35 has a nozzle 36, the coolant 37 sprayed on the rolling stock 3. The spray direction of the nozzle 36 in with respect to the running direction 38 of the rolling stock 3 gives way to one Angle β from the vertical of the surface of the rolling stock 3 from. β is advantageously 15 to 45 °. In the exemplary 4 is β = 25 °. Especially The nozzles are an advantageous embodiment of the invention both about a main spray angle α and an angle β slanted. In an advantageous embodiment of the invention the orientations of the nozzles according to FIG 3 and FIG 4 are accordingly on nozzles 7, 71, 72, 73 below the rolling stock 3 transferred according to FIG 2.

5 shows such an arrangement, the cooling device Is part of a cooling section for cooling the rolling stock 3. The rolling stock 3 is guided on a shaft 18, which with a Motor 10 is driven. The rolling stock 3 is made of coolant lines 4 and 6 sprayed with coolant 5 and 7. As a coolant 5 and 7 heated water or wet steam is used. The water evaporates when it hits the rolling stock 3. The Steam condenses in part on a cover 16. So none condensed water drips onto the rolling stock 3 is also a Hood 15 provided. The condensed water runs off and is possibly again by means of a condensate drain 20 used as cooling water. The cover 16 is with a Steam discharge pipe 22 connected to a blower 21. through of the blower 21, most of the steam is drawn off.

Claims (11)

1. Method of reducing the formation of scale on rolled stock (3) as it leaves a roll stand, heated water, in particular wet steam, being sprayed onto the rolled stock (3) downstream of the roll stand, and the heated water, in particular the wet steam, being sprayed onto the rolled stock (3) with a main spraying direction component differing from the perpendicular to the surface of the rolled stock (3).
2. Method according to Claim 1, characterized in that the heated water, in particular the wet steam, is sprayed onto the rolled stock (3) at a main spraying direction angle of 15° to 45°.
3. Method according to Claim 2, characterized in that the heated water, in particular the wet steam, is sprayed onto the rolled stock (3) at a main spraying direction angle of 15° to 30°.
4. Method according to Claim 1, 2 or 3, characterized in that the rolled stock (3) is sprayed with a main spraying direction component which is aimed at at least one outer edge of the rolled stock (3).
5. Method according to Claim 1, 2, 3 or 4, characterized in that the rolled stock (3) is sprayed with water at a temperature above 50°C, advantageously above 80°C.
6. Method according to Claim 5, characterized in that the rolled stock (3) is sprayed with water at a temperature higher than 90°C.
7. Method according to Claim 1, 2, 3, 4, 5 or 6, characterized in that the heated water is sprayed against the rolled stock (3) in the form of small droplets by means of nozzles.
8. Method according to Claim 7, characterized in that the heated water is sprayed against the rolled stock (3) as spray mist.
9. Method according to one of the preceding claims, characterized in that deoxidation gases are admixed with the heated water or the wet steam.
10. Method according to one of the preceding claims, characterized in that the temperature of the heated water is regulated.
11. Device for reducing the formation of scale on rolled stock (3) as it leaves a roll stand, for implementing according to one of the preceding claims, the device for reducing the formation of scale having a nozzle arranged downstream of the roll stand for spraying the rolled stock (3) with heated water, in particular with wet steam, with a main spraying direction component differing from the perpendicular to the surface of the rolled stock (3).

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