RU2608921C2 - Method and device for cooling metal strip or similar rolled product cooling device dynamic supply with cooling agent - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to hot rolling. Method of rolled metal strip cooling by means of cooling device (1, 1') with at least one nozzle manifold (1, 1') involves cooling agent flow direction control. Prevention of hydraulic shocks occurrence is enabled due to, that performing preliminarily accelerated cooling agent flow supply bypassing cooling device with deviation from it into return circuit (3), control of metal strip presence to be cooled and/or its temperature and deviation of preliminary accelerated flow of cooling agent from return circuit to cooling device (1, 1') depending on presence of rolled metal strip and/or its temperature, with supply of flow with preliminary acceleration into cooling device (1, 1') for metal strip cooling.

EFFECT: device comprises appropriate equipment.

16 cl, 3 dwg

Description

FIELD OF THE INVENTION

This invention relates to a method, as well as a device for dynamically supplying cooling means to a cooling device for cooling a metal strip or similar rolling product. The cooling device may include, in particular, one or more nozzle manifolds.

State of the art

The prior art already knows many systems for supplying cooling water from the upper tank for laminar cooling or cooling under pressure in hot rolling mills. To cool a hot rolled product, a significant amount of water is required, in order to sufficiently and quickly cool the strip, depending on the requirements for the manufactured product. The amount of water required to achieve a certain cooling rate is often on the order of several hundred or even thousands of cubic meters per hour. These extremely large quantities of water are routed, for example, via piping systems throttled by valves from the upper tank to the nozzle manifolds.

Such a system according to the prior art is shown by way of example in FIG. 1. Located in the upper tank 4, water is supplied through pipelines 2 to a central distributor 6. From this common distributor 6, water is supplied through other pipelines to separate nozzle manifolds 1. However, this known system has some drawbacks. For modern metal alloys or steels, it is necessary to provide the most accurate installation possible, respectively, the regulation of high cooling rates. However, this is hindered by the very large amounts of water supplied. In particular, the on and off processes cannot be performed satisfactorily quickly using existing methods, which in most cases contain control valves, due to which the cooling on process often takes more than 10 s to achieve the desired cooling rate. However, since the rolled product in many cases moves through the installation at a speed of several meters per second, the very large length of the tape is not cooled with the desired cooling rate, which leads to a decrease in the quality of this section of the strip.

Another disadvantage is the large forces that act in the switching processes on the piping system, respectively, cooling units. In particular, with fast switching processes of the cooling water supply, there is a risk that severe water hammer damage the cooling system. Such pressure peaks can even lead to failure of the cooling unit and thereby the entire rolling mill.

WO 2012/011578 A1 discloses a device for cooling a metal strip according to the restrictive part of claim 5, as well as a method for cooling a metal strip according to the restrictive part of claim 1. The cooling device comprises a plurality of groups of nozzle nozzles directed onto a metal strip, which are located in a common housing and are provided with cooling means through at least one supply pipe.

Given the prior art, the technical task of the invention is to provide an improved supply of water, which, in particular, prevents or at least significantly reduces hydraulic shocks in the inclusion processes. In addition, the technical task is to achieve faster than before the present, the desired cooling rate, for the most optimal supply of the rolled strip with coolant.

SUMMARY OF THE INVENTION

The stated technical problem is solved by using the features of a method for dynamically supplying a cooling device, in particular at least one nozzle manifold, for cooling a metal strip or similar rolled product with cooling means in accordance with paragraph 1 of the claims. The method includes at least the stage of providing a pre-accelerated, respectively, flowing stream of coolant, while the flow of coolant bypasses around the cooling device and is sent to the return circuit, as well as controlling the presence and / or temperature of the metal strip or similar rolling product to be cooled . According to the invention, the pre-accelerated flow of coolant is directed, respectively, deviated to the cooling device depending on the presence and / or temperature of a metal strip or similar rolling product, while the flow of coolant instead of going around the cooling device and directing it to the return circuit is preliminarily acceleration to a cooling device for cooling a metal strip or similar rolling product.

Due to the preliminary acceleration of the coolant and the change in direction, respectively, the deviation of this previously accelerated coolant flow can be prevented, respectively, significantly reduce the impact on the structural elements of the installation of hydraulic shocks. In addition, the cooling reaction time is significantly improved. The deflection process can be performed much faster than the acceleration process of a remote, resting amount of water. In addition to this, it is possible to achieve faster and more precisely, respectively, the desired cooling rate. Thus, the overall ability to control the volume flows used is improved overall.

According to one preferred embodiment, the pressure loss of the pre-accelerated flow of coolant when walking around the cooling device and the pressure loss of the pre-accelerated flow of coolant into the cooling device are less than 50% from each other, preferably less than 25% or even less than 10%. Preferably, both values are essentially the same. Thus, by deflecting the flow of the coolant, hydraulic shocks to the flow of the coolant are prevented when the flow of the coolant is deviated to supply it to the cooling device. In other words, the flow resistance for the flow of coolant when passing around or towards the cooling device is essentially the same or differs by less than the above value.

The deflection process is preferably carried out in less than 5 s or even less than 1.5 s. Just with such a relatively short switching time, the method according to the invention has a particular advantage.

According to one preferred embodiment, the deviation of the coolant flow is less than 5 m, preferably less than 1 m downstream of the cooling device (1) (so that the path of the coolant flow between the deflection point (5) and the cooling outlets (7) the device (1) for cooling the strip is kept as short as possible).

According to another preferred embodiment, the deflected volume flow of the coolant, respectively, the flow of coolant is greater than 150 m ³ / h and preferably more than 400 m ³ / h. Just in view of such large volume flows, this invention is particularly preferred.

In addition, the invention also relates to a device for cooling a metal strip, preferably for performing the method according to any one of the preceding claims. The device comprises, first of all, a cooling device for cooling a metal strip or similar rolling product, which comprises at least one nozzle manifold with exits for a cooling medium for supplying a cooling medium to the metal strip. In addition, the device contains guide means for directing the flow of coolant from the source of coolant to the nozzle manifold, as well as bypass means for directing the flow of coolant from the guide means to the return circuit. The switchable deflecting means of the device are designed to switch the flow direction of the coolant through the guide means to the nozzle manifold or to deviate the flow of coolant from the guide means to the bypass means.

The advantages of the device correspond essentially to the advantages of the above method.

In one preferred embodiment, the device may comprise at least one valve for controlling the volumetric flow (flowing) through the coolant flow guiding means, wherein the deflecting means are arranged downstream of the control valve.

In another preferred embodiment, the switchable deflecting means comprise at least one switchable damper for directing the flow of coolant to the nozzle manifolds or to the bypass means.

In another preferred embodiment, the guiding means further comprises a pump for increasing the volumetric flow rate. Using such a pump, an even more pre-accelerated volumetric flow can be created.

In another preferred embodiment, it is possible to bypass the pump bypass for the flow of coolant. Due to this arrangement, it is possible to cool with the help of the cooling medium pressure that is available without any pump. Water pressure can be provided, for example, using the upper tank.

Thus, in general, it is possible to create very small volume flows (for example, in laminar mode), as well as very large volume flows (in discharge mode using a pump).

In another preferred embodiment, several nozzle manifolds, preferably a maximum of ten nozzle manifolds, are combined into a first cooling group, while the first cooling group is provided with the possibility of supplying coolant through the first guide means, and for a maximum of three nozzle collectors of the first cooling group, switchable deflecting means for the direction of flow of coolant from the first guide means to the return circuit, so it is possible deflection of the flow of the coolant spray beam maximum of three groups of first cooling separately from the rest of the spray beam in the first group of cooling bypass means, respectively, in the return path.

In another preferred embodiment, several other nozzle manifolds, preferably a maximum of ten other nozzle manifolds, are combined into a second cooling group, while the second cooling group is provided with the possibility of supplying coolant through the second guide means, and switchable for a maximum of three nozzle collectors of the second cooling group deflecting means for directing the flow of coolant from the second guide means into the return a clean circuit, so that it is possible to deviate the flow of coolant from a maximum of three nozzle collectors of the second cooling group separately from the remaining nozzle collectors of the second cooling group to the bypass means, respectively, to the return circuit.

In another preferred embodiment, it is possible to supply, respectively, supply cooling means to the first and second cooling groups separately from each other by means of a source.

In another preferred embodiment, it is possible to increase the volumetric flow for each individual cooling group individually by means of a pump.

In another preferred embodiment, the device comprises several nozzle manifolds, each nozzle manifold separately from the other nozzle manifolds being matched with switchable deflecting means, and it is possible either to supply a pre-accelerated flow of coolant through the guide means to each nozzle manifold, or to supply a stream coolant through deflecting means matched to the nozzle manifold into the bypass media Twa.

In another preferred embodiment, at least one of the nozzle manifolds is supported by a support device, and switchable deflecting means are mounted on the support device. Alternatively, switchable deflecting means are located upstream of the nozzle manifold of less than 5 m, preferably less than 3 m.

All the features of the above embodiments can be combined with each other, respectively, replaced by each other.

Brief Description of the Drawings

The following is a brief description of drawings of exemplary embodiments. Other details follow from the detailed description of exemplary embodiments. The drawings schematically depict:

FIG. 1 - a device, according to the prior art, for supplying several nozzle manifolds with cooling agent;

FIG. 2 is an exemplary embodiment of a device according to the invention for cooling a metal strip or similar rolling product; and

FIG. 3 is another exemplary embodiment of a device according to the invention for cooling a metal strip or similar rolling product.

Detailed Description of Embodiments

For a better understanding, the description of FIG. 1 level of technology. Shown is the upper tank 4, which serves as a coolant reservoir. It is possible to supply coolant, as a rule, to the distributor 6, respectively, to the distribution pipe 6. From this distributor 6, the coolant can be supplied to several nozzle manifolds 1. Moreover, the nozzle collectors 1 for supplying a metal strip with coolant contain each of a plurality of outlets 7. As shown, between the distributor 6 and the corresponding nozzle manifold 1 can be located measuring sensor 15 (for example, for pressure or volumetric flow of cooling medium ba), an adjusting valve 9 or a shut-off valve 8. Using these elements, it is possible to control and direct the flow of coolant directed to the corresponding nozzle manifold 1.

In FIG. 2 shows a diagram of an exemplary embodiment according to the invention. The cooling means is similar to the prior art in FIG. 1 is provided by a drive 4. However, in contrast to that shown in FIG. 1 to the system shown in FIG. 2, an exemplary embodiment according to the invention preferably does not contain a distributor 6. Instead, in each nozzle manifold 1, coolant is supplied from the reservoir 4 separately through line 2. The flow of coolant can be increased by means of a pump 11, 11 ', respectively, of a booster pump 11, 11 '. In addition, it is possible to bypass this pump 11, 11 ′ for the flow of coolant, for example via bypass 13. This bypass 13 can be switched so that the flow of coolant is supplied either through pump 11, 11 ′, or bypass pump 11, 11 'and is routed through the piping system 2 only using the (static) pressure of the reservoir 2. In addition, the volumetric flow can be controlled using the measuring sensor 15 and / or set using the control valve 9. However, the specific egulirovanie volume flow is not the main subject of the invention and may, for example, by means of already known technical regulation. Crucial is the fact that the device according to the invention has switchable deflecting means 5, which can deflect a pre-accelerated flow of coolant from the nozzle manifold 1. Thus, the flowing, respectively, pre-accelerated volume flow can be directed, for example, first to a drain or overflow 3. Then, such a coolant stream can, for example, be returned to the accumulator 4. Another treatment of the coolant is not required, since the coolant is deflected By using means 5 it is not contaminated. The deflecting means 5 can usually comprise two switchable shut-off valves, respectively, of a valve or damper, so that a volume flow is supplied either to the nozzle manifold 1 or to the return circuit 3. However, a system with only one switchable damper is also possible. Using this system, it is possible to provide a pre-accelerated flow of coolant, which is intended to be supplied, if necessary, using deflecting means 5 to the nozzle manifold 1. Means 5 can be switched, for example, using a sensor that detects the presence and output of the strip . Alternatively or additionally, it is possible to control the temperature of the strip using a temperature sensor. Thus, depending on the temperature, it is preferable to switch, respectively, the deflecting means 5 (actuating element) as the control quantity, in order to control the supply of coolant (control effect) through the nozzle collectors 1 and their outputs 7 to the strip.

In FIG. 3 shows a diagram of a cooling device in accordance with another embodiment of the invention. In contrast to that shown in FIG. 1 to the device, several nozzle manifolds 1 are combined into a first cooling group 10, and other nozzle manifolds 1 'are combined into a second cooling group 10'. Within each of the groups 10, 10 ', with each individual nozzle manifold 1, 1' (upstream) a deflecting device 50, 50 'is matched. That is, it is possible to feed into each nozzle manifold 1, 1 ′ through a coordinated deflecting means 50, 50 ′ a pre-accelerated volumetric flow. Preferably, the corresponding deflecting means 50, 50 ′ are located as close as possible to the nozzle manifold 1, 1 ′ to be provided, so as to keep the time required for the volume flow to pass between the deflection point by means 5 and the nozzle manifold, thereby the reaction time improves, respectively, the ability to control the system.

The deflecting means 5, 50, 50 'can usually be switched electrically, pneumatically or hydraulically.

The exemplary embodiments described above serve, above all, for a better understanding of the invention and should not be construed as limiting. The scope of protection of this application is determined by the claims.

The characteristics of these examples of execution can be combined with each other or replaced by each other.

In addition, these features can be agreed by experts in the field of technology with the existing conditions or requirements.

List of items

1 nozzle manifold

1 'nozzle manifold

2 Guide means

3 Bypass / return circuit

4 Source / Top Tank

5 Swivel deflector / switching armature

6 distribution pipe

7 Coolant outlets from the nozzle manifold

8 shut-off valve

9 Control fittings

10 First cooling group

10 'Second cooling group

11 Pump / booster pump

11 'Second pump

13 Bypass

15 measuring sensor

20 First guide means

20 'Second guide means

50 First switchable deflector

50 'The second switchable deflecting means.

Claims (23)

1. A method of cooling a rolled metal strip by means of a cooling device (1, 1 ') with at least one nozzle manifold (1, 1'), comprising adjusting the flow direction of the coolant, characterized in that it includes: a) the supply of a pre-accelerated flow of coolant bypassing the cooling device with a deviation from it in the return circuit (3); b) monitoring the presence of the metal strip to be cooled and / or its temperature; and c) the deviation of the pre-accelerated coolant flow from the return circuit to the cooling device (1, 1 ') depending on the presence of the rolled metal strip and / or its temperature, with the flow being pre-accelerated to the cooling device (1, 1') for cooling metal strip. 2. The method according to p. 1, in which the difference in pressure loss of the pre-accelerated flow of coolant when going around the cooling device (1, 1 ') and when supplied to the cooling device (1, 1') is 0-20% to prevent hydraulic shock when the pre-accelerated flow of coolant deviates from the return circuit to the cooling device (1, 1 '). 3. The method according to p. 1 or 2, in which the deviation of the flow of coolant to minimize the path between the place of deviation and the outputs of the cooling device (1, 1 ') for cooling the strip is produced in less than 5 m, preferably less than 3 m downstream before exits of the cooling device (1, 1 '). 4. The method according to p. 1 or 2, in which the volume flow of the coolant to be rejected is supplied at a speed of more than 150 m ³ / h, preferably more than 400 m ³ / h. 5. A device for cooling a rolled metal strip by the method according to any one of paragraphs. 1-4, containing: at least one nozzle manifold (1, 1 ′) with exits for coolant for supplying coolant to a metal strip; guide means (2, 20, 20 ') for directing the flow of coolant from the source (4) of coolant to the nozzle manifold (1, 1'); the device contains bypass means for directing the flow of coolant from the guide means (2, 20, 20 ') into the return circuit (3) and switchable deflecting means (5, 50, 50 '), configured to switch the flow direction of the coolant through the guide means (2, 20, 20') to the nozzle manifold (1, 1 ') or to deviate the flow of coolant from the guide means ( 2, 20, 20 ') in the bypass means. 6. The device according to claim 5, which contains at least one valve (9) for regulating the volume flow flowing through the guiding means (2, 20, 20 ') of the flow of coolant, while the deflecting means (5, 50, 50' ) are located downstream of the control valve (9). 7. The device according to claim 5 or 6, in which the switchable deflecting means (5, 50, 50 ') contain respectively at least one switchable damper for directing the flow of coolant to the nozzle manifolds (1) or to the bypass means, while switchable the deflecting means (5, 50, 50 ') are configured to switch in less than 5 s, preferably in less than 1.5 s. 8. The device according to claim 5 or 6, in which the guiding means (2, 20, 20 ') comprise a pump (11, 11') to increase the volume of coolant supplied by the source (4). 9. The device according to claim 8, which is configured to bypass the pump (11, 11 ') by the flow of coolant using bypass (13). 10. The device according to claim 5 or 6, in which several nozzle manifolds (1), preferably a maximum of ten nozzle manifolds (1), are combined into a first cooling group (10) with the possibility of supplying cooling agent to the first cooling group (10) through the first guiding means (20), and for at most three nozzle manifolds (1) of the first cooling group (10) there are switchable deflecting means (50) for directing the flow of coolant from the first guiding means (20) to the return circuit with the possibility of deviating the flow of coolant from a maximum of three nozzle collectors (1) of the first cooling group (10), independently of the remaining nozzle collectors of the first cooling group (10) to the bypass means. 11. The device according to claim 10, in which several other nozzle manifolds (1 '), preferably a maximum of ten other nozzle manifolds (1'), are combined into a second cooling group (10 ') with the possibility of supplying a cooling agent to the second cooling group (10 ') through the second guide means (20'), while for a maximum of three nozzle manifolds (1 ') of the second cooling group (10') there are switchable deflecting means (50 ') to direct the flow of coolant from the second guide means (20') to return contact p, ensuring the possibility of deviation of the coolant flow maximally three spray beam (1 ') of the second cooling group (10') independently of the other spray beam (1 ') of the second cooling group (10') in the deflection means. 12. The device according to claim 11, which is configured to supply cooling means to the first and second cooling groups (10, 10 ') separately from each other by means of a source (4). 13. The device according to p. 11 or 12, which provides for the possibility of increasing the volumetric flow for each individual cooling group (10, 10 ') individually using a pump (11, 11'). 14. The device according to claim 5 or 6, which contains several nozzle manifolds (1), a maximum of three of which, separately from other nozzle manifolds (1), are made with the possibility of matching with switchable deflecting means (5) to ensure supply to a maximum of three nozzle manifolds (1) pre-accelerated flow of coolant through the guiding means (2), or feed through a deflecting means (5) flow of coolant into the bypass means agreed with a maximum of three nozzle manifolds (1) but. 15. The device according to p. 5 or 6, which contains several nozzle manifolds (1), each of which is separately from the other nozzle manifolds (1) made with the possibility of matching with switchable deflecting means (5), with the provision of a pre-accelerated flow of coolant into each nozzle manifold (1) through the guiding means (2) or by supplying a coolant stream through the deflecting means (5) coordinated with the nozzle collector (1) into the bypass means. 16. The device according to claim 5 or 6, in which at least one of the nozzle manifolds (1) is mounted on a support device on which the switched deflecting means (5) is mounted, while the switched deflecting means (5) is located upstream of the nozzle collector (1) less than 5 m.

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