DE102012215599A1 - Method and device for the dynamic supply of a cooling device for cooling metal strip or other rolling stock with coolant - Google Patents

Abstract

The present invention relates to a method for the dynamic supply of a cooling device, in particular at least one spray bar, for cooling metal strip or other rolling stock with coolant. According to the method, a pre-accelerated coolant flow is provided, which bypasses the cooling device (1) and is led into a return (3). Furthermore, the presence and / or the temperature of a metal strip or other rolling stock to be cooled is monitored and the coolant flow to the cooling device (1) is deflected depending on the presence and / or the temperature of the metal strip or the other rolling stock, the coolant flow instead of the cooling device ( 1) to be bypassed and led into a return (3), the cooling device (1) for cooling the metal strip or the other rolling stock is supplied. Furthermore, the present invention comprises a corresponding device for carrying out the method.

Description

Field of the invention

The present invention is directed to a method and apparatus for dynamically supplying a cooling device for cooling metal strip or other rolling stock with coolant. The cooling device may in particular comprise one or more spray bars.

State of the art

A variety of systems for providing cooling water from a high tank for laminar or pressure cooling in hot rolling mills is already known from the prior art. Considerable amounts of cooling water are needed to cool hot rolling stock, to adequately define and rapidly cool the strip, depending on the requirements of the finished product. The amounts of water needed to reach a given cooling rate are often on the order of hundreds or even thousands of cubic meters per hour. These extraordinarily large amounts of water are passed, for example, via ducts throttled by valves from a high tank to the spray bars.

Such a system according to the prior art is exemplary in the 1 shown. That in the high tank 4 Stored water is delivered via lines 2 a central distributor 6 fed. From this common distributor 6 the water is delivered via separate lines to the individual spray bars 1 fed. However, this known arrangement has some disadvantages. For modern metal alloys or steels, large cooling rates must also be as precisely adjustable or controllable as possible. However, this is made more difficult by the very large amounts of water used. In particular, on and off operations can not be carried out satisfactorily fast by existing concepts, which usually include control valves, whereby a switching on the cooling often takes more than 10 seconds to achieve the desired cooling rate. However, since the rolling stock in many cases with several meters per second moves through the system, a large strip length is not cooled at the desired cooling rate, resulting in quality losses of this band section result.

Another disadvantage is the high forces that act on switching operations of cooling on the piping systems or cooling systems. In particular, there is a risk in rapid switching operations of the cooling water supply that strong pressure surges damage the cooling system. Such pressure peaks can even lead to failure of the cooling system and thus the entire rolling mill.

In view of the described prior art, the technical object of the invention is to provide an improved coolant supply, which in particular avoids or at least significantly reduces pressure surges during switch-on processes. Furthermore, the technical task may be to achieve a desired cooling rate faster than before in order to optimally supply a rolled strip with coolant.

Disclosure of the invention

The asked technical problem is solved by the features of the method for dynamic supply of a cooling device, in particular of at least one spray bar, for cooling metal strip or other rolling stock with coolant according to claim 1. The method comprises at least the steps of providing a pre-accelerated or flowing coolant flow, wherein the coolant flow bypasses the cooling device and is guided into a return, as well as monitoring the presence and / or the temperature of a metal strip or other rolling stock to be cooled. According to the invention, the pre-accelerated coolant flow is diverted to the cooling device in dependence on the presence and / or temperature of the metal strip or other rolling stock, the coolant flow being bypassed and guided into a return instead of the cooling device, the cooling means for cooling the metal strip or the other rolling stock is supplied pre-accelerated.

By pre-acceleration of the coolant and the diverting or redirecting this vorbeschleunigten coolant flow acting on the system components pressure surges can be avoided or significantly reduced. Furthermore, the reaction time of the cooling improves significantly. The deflection can be done much faster than the process of accelerating a remote, stagnant amount of water. In addition, a desired cooling rate can be achieved or adjusted faster and more precisely. In general, the adjustability of the volume flows used is thus improved.

According to a preferred embodiment, the pressure loss of the pre-accelerated coolant flow when bypassing the cooling device and the pressure loss when supplying the pre-accelerated coolant flow to the cooling device differ from each other by less than 50%, preferably less than 20% or even less than 10%. Preferably, both values are substantially the same. Thus, by redirecting the coolant flow pressure surges of the coolant flow at the deflection of the Coolant flow for supplying it to the cooling device avoided. In other words, the flow resistance for the coolant flow when bypassed or directed to the cooling device is substantially the same or less than stated above.

The redirecting operation preferably takes place in less than 5 seconds or even less than 1.5 seconds. Especially with such relatively short switching times, the inventive method is of particular advantage.

According to a preferred embodiment, the deflection of the coolant flow is less than 5 m, preferably less than 1 m, upstream of the cooling device (FIG. 1 ) (so that the path of the coolant flow between the location of the deflection ( 5 ) and the outlets ( 7 ) of the cooling device ( 1 ) is kept as low as possible to cool the belt).

According to a further preferred embodiment, the volume flow of the coolant or coolant flow to be deflected is more than 150 m ³ / h and preferably more than 400 m ³ / h. Especially in view of such large volume flows, the present invention is particularly advantageous.

Furthermore, the invention is also directed to a device for cooling a metal strip, preferably for carrying out the method according to one of the preceding claims. The apparatus initially comprises a cooling device for cooling metal strip or other rolling stock, which comprises at least one spray bar with coolant outlets for dispensing the coolant onto the metal strip. Further, the apparatus includes conduit means for directing a flow of refrigerant from a source of coolant to the spray bar, and bypass means for directing the flow of refrigerant from the conduit means into a return. Switchable diverting means of the apparatus are adapted to switchably direct the flow of refrigerant through the conduit means to the spray bar or to divert the flow of refrigerant from the conduit means into the bypass means.

The advantages of the device essentially correspond to those of the method already described.

In a preferred embodiment, the device may comprise at least one valve for adjusting a volumetric flow of the coolant flow (flowing) through the conduit means, the diverting means being located downstream of the control valve.

In a further preferred embodiment, the switchable bypass means may each comprise at least one switchable flap for directing the coolant flow to the spray bars or into the bypass means.

In a further preferred embodiment, the conduit means further comprises a pump for increasing the volumetric flow provided by the source. By means of such a pump, an even more pre-accelerated volume flow can be provided.

In a further preferred embodiment, the pump can be bypassed by means of a bypass through the coolant flow. Such an arrangement allows cooling with the coolant pressure available without any pump. The water pressure can be provided by a high tank, for example.

Overall, it is thus possible to provide very small volume flows (eg laminar operation) and also very large volume flows (pressure operation by means of a pump).

In a further preferred embodiment, a plurality of spray bars, preferably a maximum of ten spray bars, combined to form a first cooling group, wherein the first cooling group coolant is supplied via first conduit means and to at most three of the spray bars of the first cooling group switchable bypass means for directing the coolant flow from the first conduit means are provided in a return, so that the coolant flow of at most three spray bars of the first cooling group is separated from the remaining spray bars of the first cooling group in the bypass means or in the return can be diverted.

In a further preferred embodiment, a plurality of further spray bars, preferably a maximum of ten further spray bars, combined to form a second cooling group, wherein the second cooling group is supplied via second conduit coolant and at each of at least three of the spray bars of the second cooling group switchable bypass means for directing the flow of coolant from the second line means are provided in a return, so that the coolant flow of at most three spray bars of the second cooling group is separated from the remaining spray bars of the second cooling group in the bypass means or in the return flow.

In a further preferred embodiment, the first and second cooling groups can be fed or supplied separately from one another by the source with coolant.

In a further preferred embodiment, the volume flow to each individual cooling group can be increased separately by a pump.

In a further preferred embodiment, the device comprises a plurality of spray bars, wherein each spray bar is assigned a switchable diverting means separately from the further spray bars so that either the pre-accelerated coolant flow can be fed to each spray bar via the conduit means or the coolant flow can be supplied to the bypass means via the diverter means assigned to the spray bar.

In a further preferred embodiment, at least one of the spray bars is supported by a support device and the switchable diverting means is mounted on this support means. Alternatively or additionally, the switchable diverting means is arranged less than 5 m, preferably less than 3 m, upstream of the spray bar.

All features of the embodiments described above can be combined with each other or replaced.

Brief description of the figures

The figures of the embodiments will be briefly described below. Further details can be found in the detailed description of the embodiments. Show it:

1 (Prior Art) a device for supplying a plurality of spray bars with coolant;

2 a schematic representation of an embodiment according to the invention of a device for cooling metal strip or other rolling stock; and

3 a schematic representation of another embodiment of the invention an apparatus for cooling metal strip or other rolling stock.

Detailed description of the embodiments

For the sake of clarity, reference will first be made to the 1 disclosed prior art. Pictured is a high tank 4 , which serves as storage for coolant. Via lines, the coolant is usually a distributor 6 or a distribution pipe 6 fed. From this distributor 6 The coolant can be a variety of spray bars 1 be supplied. This includes the spray bars 1 for applying a metal strip with the coolant in each case a plurality of outlets 7 , As shown, between the distributor 6 and the respective spray bar 1 a transducer 15 (For example, for coolant pressure or volume flow), a control valve 9 or a stopcock 8th be arranged. Through these elements can be to the respective spray bar 1 Monitor and adjust the conducted coolant flow.

The 2 shows a schematic of an embodiment of the invention. Coolant is similar to the prior art according to the 1 through a store 4 provided. In contrast to the arrangement according to 1 includes the embodiment of the invention the 2 however, it does not prefer a distributor 6 , Rather, each spray bar 1 separately via a line 2 Coolant from the store 4 fed. The provided coolant flow can be controlled by a pump 11 . 11 ' or booster pump 11 . 11 ' increase. In addition, this pump can 11 . 11 ' for the coolant flow, for example by a bypass 13 be bypassable. This bypass 13 may be switchable, so that the coolant flow either through the pump 11 . 11 ' is promoted or the pump 11 . 11 ' bypasses and only by the (static) pressure of the memory 4 through the pipe system 2 is directed. The volume flow can also by a transducer 15 be monitored and / or by a control valve 9 be adjustable. However, the specific regulation of the volume flow is not core of the invention and can be done for example by already known control engineering measures. It is crucial that the device according to the invention via switchable deflection 5 which provides a pre-accelerated flow of coolant from the spray bar 1 redirect away. For example, a flowing or pre-accelerated volumetric flow can first of all flow into an overflow or overflow 3 be guided. Such a coolant flow may, for example, subsequently follow the reservoir 4 to be led back. Further treatment of the coolant is eliminated, since the coolant when diverted by the means 5 does not get dirty. The deflection 5 In general, they may include two switchable shut-off valves or taps, allowing a flow to flow either to the spray bar 1 or the return 3 is supplied. However, it is also an arrangement with only one switchable flap possible. By the described arrangement, an already vorbeschleunigter coolant flow can be provided, which by the deflection 5 if necessary, the spray bar 1 can be fed. The means 5 can be switched for example by means of a sensor which registers the presence or the entry or exit of a band. Alternatively or additionally, the temperature of the belt can be monitored with a temperature sensor. Depending on the temperature as a controlled variable can thus preferably the deflection 5 (Actuator) can be switched or adjusted to the inflow of the coolant (control variable) via the spray bars 1 and their outlets 7 to adjust to the band.

The 3 discloses a schematic of a cooling device according to another embodiment of the invention. Unlike in the 1 shown device are several spray bars 1 to a first cooling group 10 summarized and more spray bars 1' to a second cooling group 10 ' summarized. Within each of the groups 10 . 10 ' is every single spray bar 1 . 1' (upstream) a deflection device 50 ' . 50 assigned. That is, every spray bar 1 . 1' is a by an associated deflection 50 . 50 ' vorbeschleunigter volume flow can be fed. Preferably, the deflection means are located 50 . 50 ' each as close as possible to the spray bar to be supplied 1 . 1' to the time which the volume flow for the distance between the location of the deflection by the means 5 and the spray bar needs to be kept low, whereby the reaction speed and the controllability of the system is significantly improved.

The deflection 5 . 50 . 50 ' In general, for example, they can be switched electrically, pneumatically or hydraulically.

Above all, the embodiments described above serve to better understand the invention and should not be understood as limiting. The scope of protection of the present patent application results from the patent claims.

The features of the described embodiments can be combined or replaced with each other.

Furthermore, the features described can be adapted by the skilled person to existing circumstances or existing requirements.

LIST OF REFERENCE NUMBERS

1

 spray bars

1'

 spray bars

2

 conduit means

3

 Bypass / return

4

 Source / high tank

5

 switchable deflection / switch fitting

6

 manifold

7

 Coolant outlets from spray bars

8th

 stopcock

9

 control valve

10

 first cooling group

10 '

 second cooling group

11

 Pump / booster pump

11 '

 second pump

13

bypass

15

 Transducers

20

first conduit means

20 '

 second conduit means

50

 first switchable deflection means

50 '

 second switchable deflection means

Claims (15)

Method for the dynamic supply of a cooling device ( 1 . 1' ), in particular at least one spray bar ( 1 . 1' ), for cooling metal strip or other rolling stock with coolant, comprising: a) providing a pre-accelerated coolant flow, wherein the coolant flow is the cooling device ( 1 . 1' ) and in a return ( 3 ) to be led; b) monitoring the presence and / or the temperature of a metal strip or other rolling stock to be cooled; c) diverting the already pre-accelerated coolant flow to the cooling device ( 1 . 1' ) depending on the presence and / or a defined temperature of the metal strip or other rolling stock, so that the coolant flow instead of the cooling device ( 1 . 1' ) and run in a return, the cooling device ( 1 . 1' ) is supplied pre-accelerated for cooling the metal strip or other rolling stock. The method of claim 1, wherein the pressure loss of the coolant flow when bypassing the cooling device ( 1 . 1' ) and the pressure loss when supplying the coolant flow to the cooling device ( 1 . 1' ) are less than 20% different or substantially the same, so that pressure surges in the deflection of the already pre-accelerated coolant flow to the cooling device ( 1 . 1' ) be avoided. The method of claim 1 or 2, wherein the diversion of the coolant flow to minimize the path between the location of the deflection of the coolant flow and outlets of the cooling device ( 1 . 1' ) less than 5 m, preferably less than 3 m, upstream of the outlets of the cooling device ( 1 . 1' ) he follows. The method according to one of the preceding claims, wherein the volume flow of the coolant flow to be diverted is more than 150 m ³ / h and preferably more than 400 m ³ / h. A device for cooling a metal strip, preferably for carrying out the method according to one of the preceding claims, comprising: a cooling device for cooling metal strip or other rolling stock, which comprises at least one spray bar ( 1 . 1' ) with coolant outlets for delivering the coolant to the metal strip; Conduit ( 2 . 20 . 20 ' ) for conducting a flow of coolant from a coolant source ( 4 ) to the spray bar ( 1 . 1' ); Bypass means for directing the flow of coolant from the conduit means ( 2 . 20 . 20 ' ) in a return ( 3 ); switchable diversion means ( 5 . 50 . 50 ' ) adapted to switchably directing the flow of coolant through the conduit means ( 2 . 20 . 20 ' ) to the spray bar ( 1 ) or diverting the coolant flow from the conduit means ( 2 . 20 . 20 ' ) in the bypass means. The device according to claim 5, wherein the device ( 10 ) at least one valve ( 9 ) for regulating a volume flow through the conduit means ( 2 . 20 . 20 ' ) flowing coolant flow, wherein the diversion means ( 5 . 50 . 50 ' ) downstream of the control valve ( 9 ) are arranged. The device according to claim 5 or 6, wherein the switchable bypass means ( 5 . 50 . 50 ' ) at least one switchable flap for directing the flow of coolant to the spray bars ( 1 ) or in the bypass means and / or wherein the switchable bypass means ( 5 . 50 . 50 ' ) carry out the switching process in less than 5 s, preferably in less than 1.5 s. The device according to one of claims 5 to 7, wherein the conduit means ( 2 . 20 . 20 ' ) a pump ( 11 . 11 ' ) to increase from the source ( 4 ) comprise provided volume flow of the coolant. The device according to claim 8, wherein the pump ( 11 . 11 ' ) by means of a bypass ( 13 ) Is bypassed by the coolant flow. The device according to one of claims 5 to 9, wherein a plurality of spray bars ( 1 ), preferably a maximum of ten spray bars ( 1 ), to a first cooling group ( 10 ) and the first cooling group ( 10 ) via first conduit means ( 20 ) Coolant can be supplied and in each case at most three of the spray bars ( 1 ) of the first cooling group ( 10 ) switchable diversion means ( 50 ) for directing the coolant flow from the first conduit means ( 20 ) are provided in a return, so that the coolant flow from the maximum of three spray bars ( 1 ) of the first cooling group ( 10 ) independent of the remaining spray bars of the first cooling group ( 10 ) is divisible into the bypass means. The device according to claim 10, wherein in addition a plurality of further spray bars ( 1' ), preferably a maximum of ten further spray bars ( 1' ), to a second cooling group ( 10 ' ) and the second cooling group ( 10 ' ) via second conduit means ( 20 ' ) Coolant can be supplied and in each case at most three of the spray bars ( 1' ) of the second cooling group ( 10 ' ) switchable diversion means ( 50 ' ) for directing the coolant flow from the second conduit means ( 20 ' ) are provided in a return, so that the coolant flow from the maximum of three spray bars ( 1' ) of the second cooling group ( 10 ' ) independent of the remaining spray bars ( 1' ) of the second cooling group ( 10 ' ) is divisible into the bypass means. The apparatus of claim 11, wherein the first and second cooling groups ( 10 . 10 ' ) separated from each other by the source ( 4 ) can be supplied with coolant. The device according to claim 11 or 12, wherein the volume flow to each individual cooling group ( 10 . 10 ' ) each separately by a pump ( 11 . 11 ' ) can be increased. The device according to one of claims 5 to 9, wherein the device comprises a plurality of spray bars ( 1 ) and a maximum of three of the spray bars ( 1 ) separately from the other spray bars ( 1 ) a switchable diversion means ( 5 ), so that the maximum of three spray bars ( 1 ) either the pre-accelerated coolant flow over the conduit means ( 2 ) or via which the maximum of three spray bars ( 1 ) associated diversion means ( 5 ) the coolant flow can be supplied to the bypass means; or in particular each of the spray bars ( 1 ) separately from the other spray bars ( 1 ) a switchable diversion means ( 5 ), so that each spray bar ( 1 ) either the pre-accelerated coolant flow over the conduit means ( 2 ) or via the spray bar ( 1 ) associated diversion means ( 5 ) the coolant flow can be supplied to the bypass means. The device according to one of claims 5 to 14, wherein at least one of the spray bars ( 1 ) is supported by a support means and the switchable bypass means ( 5 ) is mounted on this support device; and / or wherein the switchable diversion means ( 5 ) less than 5 m upstream of the spray bar ( 1 ) is located.

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