EP3713687B1 - Method for cooling a metallic item and cooling bar - Google Patents

Description

The invention relates to a method for cooling metal goods by applying a cooling medium from a chilled beam to the item, the cooling medium being applied through a slit in the chilled beam, the width of the slit being changed in the conveying direction of the item or the chilled beam during the cooling process. to control or regulate the cooling capacity of the cooling medium to a desired or predetermined level, the width of the slot being changed differently in sections in a direction that is both transverse to the conveying direction and perpendicular to the exit direction of the cooling medium. Furthermore, the invention relates to a chilled beam for applying a cooling medium to an item to be cooled.

A generic chilled beam is in the JP S59 171761 U disclosed. A similar solution is shown in JP H03 285709 A . A similar chilled beam and a method for cooling a metallic material by such is, for example, from CN 101020196A known. A pressurized cooling medium (usually water) is passed through the chilled beam and emerges from the chilled beam through a slit (nozzle slit) in order to reach the goods to be cooled. The desired slot width is set using a ruler-shaped component that can be screwed to the chilled beam. However, this is then fixed during the ongoing process. Variations in the cooling capacity are then only possible by changing the pressure of the cooling medium. A similar solution is shown in EP 1 420 912 B1 . Another solution is shown in WO 2014/023753 A1 .

When cooling sheet metal, water is usually applied to the sheet surface. With a long plate, the cooling water can only drain over the plate edges. As a result, the volume flow of the cooling water on the sheet surface towards the sheet edges increases with an even load across the sheet width.

This leads to an uneven cooling effect or cooling. Furthermore, there may be a process-related inhomogeneity in the temperature profile. Both lead to uneven mechanical properties and unevenness of the sheet.

Although the nozzle geometry can be adjusted in the previously known solutions, this setting cannot be changed during operation. It is therefore not possible to react to changing process parameters.

It is therefore disadvantageous that with the previously known solutions there is no possibility of varying the cooling capacity beyond the previously known extent during the process. This also applies in particular with a view to setting the volume flow of the cooling medium in a direction transverse to the conveying direction of the metal material (or the chilled beam if it is moved relative to the material to be cooled).

The invention is therefore based on the object of providing a method of the type mentioned at the outset and a chilled beam with which it is possible to allow optimal adjustment of the cooling capacity to desired or required boundary conditions, with said adjustment being possible quickly and during the process. The cooling should be improved in this respect.

The solution to this problem by the invention is characterized in terms of the method in that the slot is delimited by at least two sections of the chilled beam, with the two sections of the chilled beam, viewed perpendicular to the exit direction of the cooling medium, each having a concave part and a convex part adjoining this and where - for the purpose of adjusting the nozzle gap - the at least two sections of the chilled beam are shifted in a direction to change the width of the slot, which is both perpendicular to the exit direction of the cooling medium and perpendicular to the conveying direction (i.e. in a direction transverse to the conveying direction).

The width of the slot can be set in such a way that the width in a central area of the item to be cooled is greater than in the lateral end areas of the item to be cooled.

The proposed chilled beam for applying a cooling medium to an item to be cooled comprises electrical, pneumatic or hydraulic adjustment means with which the width of the slot can be changed in the conveying direction (of the item or the chilled beam), with the invention providing that the slot is divided by at least two Sections of the chilled beam is delimited, wherein the at least two sections of the chilled beam have an S-shaped course, viewed perpendicularly to the exit direction of the cooling medium, and wherein the at least two sections of the chilled beam can be displaced relative to one another to change the width of the slot in a direction that is both is perpendicular to the exit direction of the cooling medium and perpendicular to the conveying direction.

The adjustment means can be connected to a controller, with at least one sensor connected to the controller being arranged, with which a physical property of the item can be determined.

The proposed concept and the proposed chilled beam is suitable for heavy plate rolling mills, in hot strip mills and in heat treatment lines, especially for steel materials. Equally, however, an application for non-ferrous metals is possible. In particular, it can also be used in quenches with slotted-nozzle chilled beams for the application of cooling water.

A chilled beam with a slit nozzle and a nozzle geometry that can be changed over the width is thus made available. This makes it possible based on to influence the nozzle geometry in a targeted manner according to defined specifications, namely during the cooling process itself.

The present invention thus provides chilled beams with slotted nozzles, in which case the nozzle geometry and thus the volume flow can be changed over the width of the material to be cooled during operation. In this way, a control system can be implemented which makes specifications for an intended actuator system.

The slot nozzle of the proposed cooling beam preferably consists of at least two parts, with at least one part of the nozzle being designed to be movable. The slot geometry can be changed, for example, by feeding one nozzle part in the direction of the other. This delivery can be uneven across the nozzle width. For example, less cooling water can be applied towards the edges. This helps to eliminate the disadvantage mentioned above.

A further possibility is to provide the nozzle parts with a special contour, in particular with an S-shaped geometry, and then to change the nozzle gap by axially displacing the parts relative to one another.

The adjustment of the slot can be done manually or automatically. An actuator is provided for automatic slot adjustment and the variable water exposure that this makes possible across the sheet width. This actuator preferably receives the adjustment values from an automation system (control system). The automation system receives information about the sheet metal dimensions and the material quality (primary data), target properties (hardness, strength, etc.), data from process sensors (material temperatures, actual flatness, etc.) before, in and after the cooling device and actual properties achieved after Process. With this information, the system is able to send adjustment values to the actuators. This continuous feedback of the actual properties makes it possible to select the values in such a way that the sheet properties are distributed homogeneously especially over the width adjusts. However, it is also possible to specifically set different properties across the width of the sheet.

It can happen again and again (despite the filters in the inlets of the chilled beam) that clogging or deposits occur in the cooling water nozzles. The nozzle gap can be opened by adjusting the nozzle gap of the slot nozzle, as a result of which impurities, for example in the form of lumps or small plates, can be flushed out of the slot.

The proposed solution makes it possible to variably set or adjust the geometry of a slot nozzle. This adjustment can also be made during ongoing operation while an item (sheet) is being cooled. This makes it possible to apply different levels of water to the head or foot of the sheet metal.

Furthermore, a regulation can be provided which, depending on various process and default values, prescribes desired values for the control of the nozzle geometry.

With these measures, better flatness and optimized material properties can be achieved during the cooling process.

The proposed solution makes it possible to specifically control the cooling medium running off at the side in such a way that a desired cooling takes place over the width of a strip. In this way, in particular, uniform cooling over the strip width can be achieved.

Fig. 1

schematisch die Seitenansicht eines Kühlbalkens, dargestellt im Schnitt, der ein in Förderrichtung vorbeilaufendes metallisches Gut kühlt,

Fig. 2a

den Schlitz des Kühlbalkens, gesehen in Austrittsrichtung des Kühlmediums, in einer ersten Relativposition zweier Abschnitte des Kühlbalkens und

Fig. 2b

den Schlitz des Kühlbalkens gemäß Figur 2a in einer zweiten, verschobenen Relativposition der Abschnitte des Kühlbalkens.

In the drawing an embodiment of the invention is shown. Show it:

1

Schematically the side view of a chilled beam, shown in section, which cools a metallic good passing in the conveying direction,

Figure 2a

the slit of the chilled beam, seen in the exit direction of the cooling medium, in a first relative position of two sections of the chilled beam and

Figure 2b

according to the slot of the chilled beam Figure 2a in a second, displaced relative position of the sections of the chilled beam.

In figure 1 a chilled beam 2 can be seen, under which a metal material 1 in the form of a metal strip runs in a conveying direction F and is cooled by a cooling medium which is discharged from the chilled beam 2 . The horizontal direction Q transverse to the conveying direction F is perpendicular to the plane of the drawing figure 1 .

In a manner known per se, the chilled beam 2 has a slot 3 which extends over the entire width of the metal material 2, ie in the direction Q, and has a width B—measured in the conveying direction F.

As figure 1 can be seen, the exit direction A of the cooling medium is arranged at a certain angle to the surface of the material 1, which, however, does not change the fact that the width B extends over a certain amount in the conveying direction F.

It is essential that the width B of the slot 3 of the chilled beam 2 can be changed during the cooling process, for which purpose adjustment means 8 are provided. These are only shown schematically in figure 1 indicated and can be of any type (electric, pneumatic, hydraulic).

Two sections 4 and 5 of the chilled beam 2 can be moved or adjusted relative to one another by said adjusting means, i. H. one of the sections, section 5 in the exemplary embodiment, is moved in a feed direction Z in order to set the width B of the slot 3 .

In figure 1 indicates that a physical variable (it can be the flatness of the item 1 or its temperature) by means of a sensor 10 detected and the measured value of a controller 9 is supplied. Based on an algorithm stored in it, this can then give a control signal to the adjustment means 8, with which a specific width B is set, so that a desired property of the item 1 can be achieved. It can therefore be ensured in a closed control loop that the width B of the slot 3 of the chilled beam is set in such a way that a desired property of the item 1 results.

A specific and preferred embodiment of the sections 4 and 5 of the chilled beam 2 is from the Figures 2a and 2b out.

Seen in the exit direction A of the cooling medium in the Figures 2a and 2b is perpendicular to the plane of the drawing, the two sections 4, 5 have concave parts 6 and convex parts 7, so that the illustrated S-shaped course of the boundary of the slot 3 results.

while in Figure 2a the two sections 4 and 5 are in an initial position and the slot 3 has a largely constant width B (even if it is curved). Figure 2b the two sections 4 and 5 are shifted in direction Q relative to each other (the upper section 4 was in figure 2 shifted to the right and the lower section 5 to the left). Accordingly, the shape of the slit 3 has changed.

How out Figure 2b As can be seen, more cooling medium now reaches the material in the central area of the goods to be cooled due to the greater width B of the slot 3, while the two side areas of the sheet metal 1 or end areas of the slot 3 are narrower and less cooling medium thus escapes.

By correspondingly shifting the two sections 4 and 5 in the direction Q, the quantity and the distribution of the exiting cooling medium can be influenced and the cooling process can thus be controlled or regulated.

This takes place actively in particular during the cooling process, so that changing circumstances with regard to the process can be influenced by influencing the cooling.

Reference list:

1

metallic good

2

chilled beam

3

slot of the chilled beam

4

section of the chilled beam

5

section of the chilled beam

6

concave part

7

convex part

8th

adjusting means

9

steering

10

sensor

B

width of the slot

f

Conveying direction of the goods / the chilled beam

Z

delivery direction

Q

Direction transverse to the conveying direction

A

Exit direction of the cooling medium

Claims (4)

1. Method for cooling a metallic material (1) by application of a cooling medium from a cooling bar (2) to the material (1), wherein the cooling medium is applied through a slot (3) of the cooling bar (2), wherein during the cooling process the width (B) of the slot (3) in conveying direction (F) of the material (1) or the cooling bar (2) is changed so as to control or regulate the cooling performance of the cooling medium to a desired or predetermined level, wherein the width (B) of the slot (3) in a direction, which is both transverse (Q) to the conveying direction (F) and perpendicular to the exit direction (A) of the cooling medium, is differently changed in sectionwise manner,
   characterised in that
   the slot (3) is bounded by at least two sections (4, 5) of the cooling bar (2), wherein the two sections (4, 5) of the cooling bar (2) as seen perpendicularly to the exit direction (A) of the cooling medium each have a concave part (6) and a convex part (7) connected therewith and wherein for changing the width (B) of the slot (3) the at least two sections (4, 5) of the cooling bar (2) are displaced in a direction which is both perpendicular to the exit direction (A) of the cooling medium and perpendicular to the conveying direction (F).
2. Method according to claim 1, characterised in that the width (B) of the slot (3) is so set that the width in a centre region of the material (1) to be cooled is greater than in the lateral end regions of the material (1) to be cooled.
3. Cooling bar (2) for application of a cooling medium in an exit direction (A) to a material (1) to be cooled, wherein the cooling bar (2) has a slot (3) through which cooling medium is applied, wherein the width (B) of the slot (3) extends in a direction perpendicular to the exit direction (A), wherein electrical, pneumatic or hydraulic adjusting means (8) by which the width (B) of the slot (3) can be changed perpendicularly to the exit direction (A) are present,
   characterised in that
   the slot (3) is bounded by at least two sections (4, 5) of the cooling bar (2), wherein the at least two sections (4, 5) of the cooling bar (2) as seen perpendicularly to the exit direction (A) of the cooling medium have an S-shaped course and wherein for changing the width (B) of the slot (3) the at least two sections (4, 5) of the cooling bar (2) are displaceable relative to one another in a direction which is perpendicular to both the exit direction (A) of the cooling medium and the direction of the dimensioning of the width (B).
4. Cooling bar according to claim 3, characterised in that the adjusting means (8) are connected with a control (9), wherein at least one sensor (10), which is connected with the control (9) and by which a physical characteristic of the material (1) can be ascertained, is provided.

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