Device and method for controlled secondary cooling of a cast metal strand

Abstract

Device (1) for controlled secondary cooling of a metal strand guided in a strand guide device of a continuous casting plant, comprising a plurality of spray nozzles (D) provided on a segment (2) of the strand guide device and connectable via cooling lines (3, 4) to a clamping plate for connection to a distribution chamber, wherein a cooling medium can be applied to the metal strand through the spray nozzles (D), wherein different cooling zones (K) are provided by the spray nozzles (D) on the segment (2). i ) are definable and in a respective Cooling zone (K i ) at least one spray nozzle (D) is included, Adjusting devices (E i ), which are connected to the cooling lines (3, 4) for the spray nozzles (D), wherein the adjusting devices (E i ) are connected upstream of the spray nozzles (D) and the supply of cooling media to the spray nozzles (D) is controlled by the adjusting devices (E) i ) is controllable, and Switching valves (Z i , ZW i ), which are connected to a respective control line connection of the adjusting devices (E i ) are assigned and can be subjected to an adjustable control pressure (P, Pt), so that the adjusting elements (E i ) depending on the control pressure (P, Pt) for the switching valves (Z) i , ZW i ) are switchable, characterized by that the switching valves (Z i , ZW i ) connected to a common control pressure line (5) and switchable depending on variable pressure values ​​for the control pressure (P, Pt) in order to control the adjusting devices (E i ) to open or close and thereby supply cooling media to the spray nozzles (D) in the respective cooling zones (K i ) to control.

Description

[0001] The invention relates to a device for controlled secondary cooling of a cast metal strand according to the preamble of claim 1 or claim 3, and a corresponding method for controlled secondary cooling according to the preamble of claim 23 or claim 25.

[0002] In continuous steel casting, the solidification of a cast metal strand after it leaves the mold is achieved through secondary cooling in the strand guide. Within the strand guide, a cooling medium, for example water or a water / air mixture, is injected under pressure directly onto the partially solidified strand shell of the metal strand to selectively remove heat from the metal strand.

[0003] In continuous casting, metal strands of varying widths are typically produced. A segment of the strand guide can have multiple cooling zones arranged across its width. Depending on the strand width and, if applicable, a desired temperature profile across the segment's width, the cooling zones within a segment can be selectively activated or deactivated, or their coolant flow can be reduced to regulate the supply of cooling medium across the segment's width.

[0004] From DE 10 2010 052 247 A1, a controlled secondary cooling system for a continuous casting plant is known, wherein a plurality of cooling zones are provided across the width of a segment. In this system, the supply lines for each cooling zone are assigned corresponding adjusting devices and / or control valves, by means of which the respective coolant supply for the cooling zones is regulated. The pressure, as a control variable for these adjusting devices, is set via controllable pneumatic valves and supplied to each of them via separate lines through a control air clamping plate. Such a regulation of the coolant supply to the cooling zones has the disadvantage of requiring a high level of equipment complexity with regard to the piping technology and a complex control sequence that must be set individually for each cooling zone.

[0005] WO 2011 / 038800 A1 discloses a continuous casting plant which has separately controlled cooling zones across the width of a segment. A separate control loop is provided for each width zone of a segment, which is correspondingly complex.

[0006] Accordingly, the invention is based on the objective of creating a simplified supply of cooling medium to cooling zones across the width of a segment, while keeping the control engineering effort for targeted control of specific cooling zones low.

[0007] This problem is solved by a device having the features of claim 1 and claim 3 and by a method having the features of claim 23 and claim 25. Advantageous embodiments of the invention are defined in the dependent claims.

[0008] A first embodiment of a device according to the invention and a corresponding method for the controlled secondary cooling of a metal strand guided in a strand guide of a continuous casting plant provides a plurality of spray nozzles which are provided on a segment of the strand guide and can be connected via cooling lines to a clamping plate for connection to a distribution chamber. Cooling medium can be sprayed onto the metal strand through the spray nozzles. Different cooling zones can be defined on the segment using the spray nozzles, with each cooling zone containing at least one spray nozzle. Adjustment devices are located upstream of the spray nozzles and are connected to the cooling lines for the spray nozzles, whereby the supply of cooling medium to the spray nozzles can be controlled by the adjustment devices.Switching valves are assigned to a specific control line connection of the adjusting elements and can be subjected to an adjustable control pressure, allowing the adjusting elements to be switched depending on the control pressure for the switching valves. The switching valves are connected to a common control pressure line and can be switched depending on varying control pressure values ​​to open or close the adjusting elements, thereby controlling the supply of cooling medium to the spray nozzles in a respective cooling zone.

[0009] A key feature of the aforementioned embodiment of the invention is that the switching valves for adjusting or switching the adjusting elements are not controlled via separate control circuits, but rather via a common control pressure line. By changing the control pressure in this common control pressure line, it is possible to control specific switching valves with their associated adjusting elements and thus the supply of cooling media to spray nozzles in specific cooling zones. Only a single control device for the control pressure in the common control pressure line is required for this purpose, which simplifies the design and equipment complexity of the invention.

[0010] An alternative embodiment of the device according to the invention and a corresponding method for the controlled secondary cooling of a metal strand guided in a strand guide of a continuous casting plant provides at least one spray nozzle, which is mounted on a segment of the strand guide and can be connected via at least one cooling line to a clamping plate for connection to a distribution chamber. Cooling medium can be applied to the metal strand through the spray nozzle. At least one cooling zone can be defined on the segment using the spray nozzle. Adjustment devices are located upstream of the spray nozzle and are connected to the cooling line for the spray nozzle, whereby the supply of cooling medium to the spray nozzle can be controlled by the adjustment devices.Switching valves are assigned to a respective control line connection of the adjusting devices and can be subjected to an adjustable control pressure, so that the adjusting devices can be switched depending on the control pressure for the switching valves. Two cooling lines are provided for supplying the spray nozzle with cooling medium, with two adjusting devices assigned to the spray nozzle, one of the adjusting devices being connected to one cooling line and the other to the other cooling line, with a common supply line leading from each adjusting device to the spray nozzle.

[0011] The last-mentioned embodiment of the invention is characterized in that the cooling medium is supplied to the spray nozzle via two cooling lines. The adjusting elements allow the user to select from which of the two cooling lines the cooling medium flows into the common supply line for delivery to the spray nozzle. It is advantageous if the quantity or pressure of the coolant supplied to the two cooling lines is different. By opening both adjusting elements, the cooling medium flows from both cooling lines to the spray nozzle, resulting in a correspondingly high cooling capacity. By closing one of the two adjusting elements, the cooling medium can only flow from the other cooling line to the spray nozzle via the common supply line, thereby reducing the cooling capacity due to the lower quantity of cooling medium supplied.The provision of two cooling lines and the ability to selectively supply the coolant to the injection nozzle by switching the adjusting devices through which the injection nozzle is connected to the two cooling lines ensures a robust and rapid change in the amount of coolant supplied to the cooling zone, as required during the continuous casting process.

[0012] In an advantageous embodiment of the invention, a plurality of spray nozzles can be provided on the segment, each of which can be connected to the clamping plate via the two cooling lines. These spray nozzles can define a plurality of different cooling zones on the segment, preferably arranged across its width. It is possible to assign the plurality of spray nozzles to different cooling zones or to connect them in such a way that different cooling zones can be defined as needed. By appropriately adjusting the control pressure in the common control pressure line for the switching valves, spray nozzles in specific cooling zones can either be completely shut off or supplied with a reduced amount of coolant.This is preferably done from an edge of the segment towards the center of the segment, for example by a successive increase in the control pressure in the common control pressure line.

[0013] In an advantageous embodiment of the invention, the cooling lines are arranged on the segment. This means that the sections of the cooling lines, namely between the clamping plate and the adjustment elements for each cooling zone, are arranged on a segment of the pipe assembly. The same applies to the switching valves that are assigned to or upstream of the respective adjustment elements. Advantageously, the switching valves and / or the adjustment elements can also be integrated or combined in a single unit in the form of a valve manifold. Such a valve manifold can also be mounted on a segment of the pipe assembly. As a result, this leads to a compact design because the valve manifold can be placed directly at the point of use, i.e., on the segment. Furthermore, complex piping for the respective cooling zones is eliminated, and the piping for each segment can also be of a simpler design.

[0014] The switching valves can be actuated with all known fluids, e.g., pneumatically with compressed air or hydraulically with water or oil. This has the advantage that the switching valves do not require any electrical energy for their operation, so that no electrical components are required on a valve manifold and / or on a segment of the pipeline guidance system.

[0015] The invention is described in detail below with reference to the figures mentioned. The figures show: Fig. 1 a schematically simplified representation of a device according to the invention, in a starting position or basic position; Fig. 2-6 schematic simplified representations of the device of Fig. 1, in various operating positions; and Fig. 7 symbolic representations of the operating states of adjusting elements in a device according to one of the Fig. 1-6.

[0016] Fig. Figure 1 schematically illustrates a simplified device according to the invention for the controlled secondary cooling of a metal strand guided in a strand guide of a continuous casting plant. The strand guide serves to guide the metal strand after it exits a mold of the continuous casting plant and comprises a plurality of segments, each arranged longitudinally in the strand guide and each of which can be installed in the strand guide as a structural unit and removed again for maintenance or repair purposes. The segments can each have a plurality of pairs of rollers, which can be installed opposite each other in an upper frame and a lower frame. The phrase "... on a segment" or "... on the segment" means, within the meaning of the present invention, an arrangement on, attached to, or in the segment, preferably as a structural unit.The aforementioned strand guidance device as such is state of the art and is therefore not shown in the drawing.

[0017] The device 1 comprises a plurality of spray nozzles D. By means of these spray nozzles D, different cooling zones K can be created on a respective segment 2 of the strand guide device. i over whose width they are formed. In Fig. Segment 2 is simplified as a dashed rectangle, where "B" symbolizes the width of segment 2. A central cooling zone K is located in a central area of ​​segment 2. Z arranged. A first cooling zone K is located at one edge of segment 2. I , wherein between the first cooling zone K I and the central cooling zone K Z a second cooling zone K II and a third cooling zone K III are arranged. In each of these cooling zones, in the transport direction of the metal strand (see arrow T in Fig. 1) a plurality of spray nozzles D arranged from which coolant can be sprayed under pressure onto the metal strand.

[0018] On segment 2, a total of seven cooling zones are provided across width B, with cooling zones K I , K II and K II , each in pairs on the segment and symmetrical to its center or the central cooling zone K Z are arranged.

[0019] In Fig. Figure 1 shows a circuit diagram for device 1, illustrating the connection of the spray nozzles D in the respective cooling zones with adjusting devices and switching valves and thus the controllability of the spray nozzles D with coolant.

[0020] The spray nozzles D in the first cooling zone K I are connected to a first supply line V I connected to a first adjusting organ E I leads to the spray nozzles D in the second cooling zone K. IIare connected to a second supply line V II connected to a second adjusting organ E II,1 and to a third adjusting organ E II,2 This leads to the spray nozzles D in the third cooling zone K. II , are connected to a third supply line V III connected to a fourth adjusting organ E III,1 and to a fifth adjusting organ E III,2 This leads to the spray nozzles D in the central cooling zone K. Z are connected to a central supply line V Z connected to a central first adjusting organ E Z,1 and to a central second adjusting organ E Z,3 leads.

[0021] The spray nozzles D in the respective cooling zones are supplied with cooling medium, preferably cooling water, via a first cooling line 3 and a second cooling line 4. The first and second cooling lines 3, 4 each lead to a clamping plate, by means of which the cooling lines 3, 4 can be connected to a water distribution chamber (not shown). For the purposes of the present invention, a "clamping plate" is understood to be a detachable coupling point by means of which the cooling zones or the associated cooling lines can be connected to a cooling medium supply on a segment. Fig. Reference numeral 100 denotes a fictitious dividing line between the water distribution area and segment 2.

[0022] Applying cooling water from the spray nozzles D to the respective cooling zones on the metal strand is known as single-component cooling. Alternatively, according to the present invention, it is also possible to supply a mixture of water and air to the spray nozzles D via the cooling lines 3, 4, so that, according to the principle of two-component cooling, a mixture of water and compressed air is sprayed onto the metal strand through the spray nozzles D. For the sake of simplicity, the following discussion will always refer to a supply of cooling water to the spray nozzles D, without this being interpreted as limiting the discussion to single-component cooling.

[0023] The adjusting devices, which are located upstream of the spray nozzles D in the respective cooling zones, are connected to the cooling lines. Specifically, the adjusting devices are E II,1 E III,1 , and E Z,1 connected to the first cooling line 3, wherein the adjusting elements E I , E II,2 , E III,2and E Z,2 Each is connected to the second cooling line 4. Cooling water is supplied to the spray nozzles D via cooling lines 3 and 4 and sprayed onto the metal strand.

[0024] Regarding cooling lines 3 and 4, the selected flow rate of cooling water can be different. For example, a flow rate W1 of cooling water in the first cooling line 3 can be greater than a flow rate W2 of cooling water in the second cooling line 4, such that W1 > W2. This is achieved by adjusting the respective switching position of the control elements E. II , E III or E Z The amount of coolant supplied to the spray nozzles D in the respective cooling zones K can be adjusted. II , K III or K Z Coolant is supplied either only from the first cooling line 3, or only from the second cooling line 4, or from both of these cooling lines. Coolant is supplied to the spray nozzles D in the first cooling zone K. Iis determined by a switching position of the adjusting device E I set to ensure a corresponding supply of coolant flow rate W2 from the second cooling line 4.

[0025] The adjustment devices for the spray nozzles D in the respective cooling zones each have control line connections and can be adjusted by switching valves assigned to these control line connections, which can be subjected to an adjustable control pressure. This is explained in detail below.

[0026] A number of switching valves are connected to a common control pressure line 5, through which the adjustment devices for the secondary cooling of the cooling zones can be controlled or switched. A first switching valve Z1 is connected to the control line connection of the first adjustment device E. I and the control line connection of the second adjusting device E II,1Upstream. Parallel to the first switching valve Z1, a first switching directional control valve ZW1 is arranged in the common control pressure line 5, which is connected via a first changeover valve WV1 to the control line connection of the third adjusting element E II,2 is connected upstream. In this case, a control line connection of the first switching directional valve ZW1 is connected to an output of the first switching valve Z1.

[0027] Parallel to the first switching valve Z1, a second switching valve Z2 is arranged in the common control pressure line 5, the output of which is connected on one side to the first changeover valve WV1 and on the other side to the control line connection of the fourth adjusting element E III,1 is connected. Parallel to the first and second switching valves Z1 and Z2, respectively, a second switching directional valve ZW2 is arranged in the common control pressure line 5, which is connected via a second changeover valve WV2 to the control line connection of the fifth adjusting element E.III,2 is connected.

[0028] In the control pressure line 5, a third switching valve Z3 is arranged parallel to the switching valves Z1, Z2, the output of which is connected on one side to the second changeover valve WV2 and on the other side to the control line connection of the central first adjusting device E Z,1 is connected. In the first control pressure line 5, a third switching directional control valve ZW3 is arranged parallel to the third switching valve Z3, from which an output line leads to the control line connection of the central second adjusting device E. Z,2 leads.

[0029] Finally, a fourth switching directional valve ZW4 is provided, which is connected with one input in parallel to switching valves Z1-Z4 or to the third switching directional valve ZW3, and with another input to the output of the third switching valve ZW3. One output of the fourth switching directional valve ZW4 is connected to the control line connection of the central first adjusting element E. Z,1 tied together.

[0030] The control line connection of the second switching directional valve ZW2 is connected to an output of the second switching valve Z2. The control line connections of the third and fourth switching directional valves ZW3 and ZW4 are connected to an additional control pressure line 6 and are connected in parallel to each other.

[0031] All adjusting mechanisms E i are spring-loaded and depicted as Fig. 1 is shown in their respective open positions. This allows the cooling water from the first cooling line 3 and from the second cooling line 4 to flow through the adjusting devices and the supply lines connected therein to the respective cooling zones.

[0032] All of the switching directional control valves ZW i are also spring-loaded, and in the representation of Fig. Figure 1 shows an operating position when these valves switch the control pressure line 5. Details of these switching positions of the directional control valves are explained in detail below.

[0033] In the representation of Fig. 1 indicates a segment boundary with the reference symbol "200". This is because the described switching valves and adjusting devices are located in Fig. The reference numeral "7" indicates that the elements are located below the segment boundary 200. This means that these elements are arranged together on segment 2. The reference numeral "7" denotes a valve manifold in which the switching valves Z1-Z3, the switching directional valves ZW1-ZW3, and the two changeover valves W1 and W2 can be integrated. The same applies to the switching directional valves ZW3 and ZW4, which can be integrated into a valve manifold 8. Alternatively, it is also possible to design valve manifolds 7 and 8 as a single, combined valve manifold mounted on segment 2.

[0034] The control pressure line 5 is connected to a spring-loaded 3 / 2-way valve 9. The 3 / 2-way valve 9 has a control line port to which a reset pressure Px can be applied. If the reset pressure Px is applied to the control line port of the 3 / 2-way valve 9, as shown in the circuit diagram of Fig. As shown in Figure 1, the control pressure line 5 is vented to the environment and thus depressurized. Consequently, all switching valves located in the control pressure line 5 are reset to their respective initial or default positions.

[0035] The reference symbol “10” indicates in Fig. 1 indicated that the adjusting organs E i They can also be grouped together to form a valve manifold. This valve manifold 10 can also be mounted on segment 2. For the purpose of further discussion, the arrangement of the adjusting elements is specified such that the first adjusting element E I is arranged in a first row I; the second and third adjusting mechanism E II,1 and E II,2 are arranged in a second row II; the fourth and fifth adjusting mechanism E III,1 and E III,2 are arranged in a third row III, and finally: the central first adjusting element E Z,1and the central second adjusting mechanism E Z,2 are arranged in a row Z. The rows I-III and Z are also shown in the representation of Fig. Figure 7 is shown symbolically and explained in detail below.

[0036] With reference to the Fig. Sections 2-6 below explain how a change in the control pressure in the control pressure line 5 or the auxiliary control pressure line 6 actuates the aforementioned switching valves and thereby controls the adjusting elements to supply coolant to the spray nozzles D in the respective cooling zones or, if necessary, to reduce or block the coolant supply. In this context, it should be noted that the illustrations of Fig. 2-6 each of the device 1 according to Fig. 1 correspond to and illustrate different operating states of the switching valves or adjusting devices, depending on the set control pressure in the common control pressure line 5 or the auxiliary control pressure line 6. Furthermore, it should be noted that in Fig. 7. The respective open and closed positions of the respective adjusting devices E are indicated by full circles or rings. i in the rows I, II, III and Z respectively. Here, the groups of circles next to the numbers "1" to "6" represent the Fig. to be assigned 1-6. This means that in Fig. 7 the circles next to the number “1” in the circuit diagram of Fig. 1 corresponds to the fact that the circles next to the number 2 correspond to the circuit diagram of Fig. 2 correspond, etc.

[0037] The invention now works as follows: In the circuit diagram of Fig. A pressure Px is applied to the control line connection of the 3 / 2-way valve 9, causing the control pressure line 5 to be vented to the environment. Consequently, all spring-loaded switching valves and all spring-loaded adjusting elements of the device 1 return to their initial position. This opens the two cooling lines 3, 4 towards the cooling zones via all adjusting elements, allowing cooling water with the proportions W1, W2 to flow to the spray nozzles D in the cooling zones K. II , K III and K Z is supplied to the spray nozzles D in the first cooling zone K. I Cooling water containing W2 is supplied. In the operating position as shown in the diagram. Fig. 1. The cooling zones on segment 2 reach their maximum cooling capacity. In Fig. In figure 7, this is expressed by the fact that, in addition to the number 1, the circles corresponding to the respective adjusting elements are each filled as rings.

[0038] To reduce the cooling capacity in certain cooling zones, a control pressure P is applied to an inlet line of the 3 / 2-way valve 9, whereby the pressure Px applied to the control line connection is set to zero. Accordingly, the 3 / 2-way valve then opens due to the spring action, so that the pressure P enters the common control pressure line 5. (See circuit diagram of...) Fig. 2. The pressure P is set lower than a predetermined initial pressure P1. By connecting the first switching directional valve ZW1, the second switching directional valve ZW2, and the third switching directional valve ZW3 in parallel, the pressure P is then simultaneously applied to the control line connections of the third adjusting element E. II,2 , of the fifth adjusting organ E III,2 and the central second adjusting organ E Z,2so that these adjusting elements are moved into their closed position. Accordingly, the W2 portion of the cooling water is blocked (see solid black circles in Fig. 7, next to the number 2), so that spray nozzles D in the cooling zones K Z , K II and K II , are supplied only with the portion W1 from the first cooling line 3. In this way, the cooling capacity in the cooling zones K is thus Z , K II and K II , compared to the circuit diagram of Fig. 1 reduced.

[0039] In the circuit diagram of Fig. 3. The control pressure P is further increased, namely to a value greater than a predetermined pressure P1. As a result, the cooling capacity in the first cooling zones K is increased. I and in the second cooling zones K I, reduced. Specifically, increasing the control pressure to a value greater than P1 causes the first switching valve Z1 to open. Consequently, the pressure P1 is present at the control line connections of both the first adjusting element E and the control valve E. I as well as the second adjusting organ E II,1 on, so that these adjusting mechanisms close. This is in Fig. 7, next to the number 3, is symbolized by solid black circles. This is due to the closed position of the first adjusting element E. I No coolant reaches the spray nozzles D in the first cooling zone K I . Switching on the first switching valve Z1 also results in the pressure P1 being present at the control line connection of the first switching directional control valve ZW1, so that switching this valve opens the control line connection of the third adjusting device E II,2The system is vented and this valve returns to its open initial position. This then results in the spray nozzles D in the second cooling zone K being supplied with coolant. II Cooling water is supplied only with the component W2 from the second cooling line 4, because, as explained, the second adjusting device E connected to the first cooling line 3 II,1 is closed. Because W2 < W1, the cooling capacity in the cooling zones K is therefore II compared to the circuit diagram of Fig. 2 reduced.

[0040] Fig. Figure 4 illustrates a further increase in pressure P to a value greater than a predetermined second pressure P2, which further reduces the resulting cooling capacity for the cooling zones. Because the control pressure P is selected to be greater than the predetermined second value P2, the second switching valve Z2 opens, so that the pressure P now reaches the control line connections of the third adjusting element E. II,2 and the fourth adjusting organ EIII,1 is in contact and these adjusting elements close accordingly. Since the second adjusting element E II,1 The cooling water supply through the second supply line V remains closed. II to the spray nozzles D in the second cooling zone K II Completely locked. Switching on the second switching valve Z. II This also results in the pressure P being present at the control line connection of the second switching directional valve ZW2, thus affecting the control line connection of the fifth adjusting element E. III,2 The second-way valve W2 opens to the environment and is vented accordingly. This opens the fifth adjusting element E. III,2 again, with the consequence that now through supply line V III Cooling water with the component W2 from the second cooling line 4 to the spray nozzles D in the third cooling zones K II, is supplied. Due to the condition W2 < W1, this corresponds to a reduced cooling capacity compared to the circuit diagram of Fig. 3.

[0041] Fig. Figure 5 illustrates an operating condition for so-called "dry casting," in which all adjusting elements are locked or closed, and consequently no cooling water reaches the spray nozzles D in the respective cooling zones. In the Fig. In 7, this is symbolized by the black circles next to the number 5. The closing of all adjusting elements is shown in the circuit diagram. Fig. 5. This is achieved by a further increase of the control pressure P to a value greater than a third predetermined pressure P3. This causes the third switching valve Z3 to open, whereby the pressure P is transferred via the second changeover valve WV2 to the control line connection of the fifth adjusting device E. III,2and, on the other hand, via the fourth switching directional valve ZW4 to the control line connection of the central first adjusting device E Z,1 This results in the fifth adjusting element E III,2 and the central first adjusting organ E Z,1 also close.

[0042] During the operating conditions according to the Fig. 2-4 is the cooling capacity for the spray nozzles D in the central cooling zone K Z compared to the operating state of Fig. 1 reduced because the central second adjusting organ E Z,2 Each is closed and the cooling water only flows from the first cooling line 3 to the spray nozzles D in the central cooling zone K Z is supplied. The cooling capacity for the central cooling zones K can be adjusted using the control pressure Pt. ZThis can be further reduced by supplying only the smaller proportion of W2 from the second cooling line 4 to the spray nozzles D in the central cooling zone K, instead of the proportion W1 from the first cooling line 3. Z is supplied. This is shown in the circuit diagram of Fig. 6 is shown, where the control pressure Pt is chosen to be greater than zero and the control pressure P is as shown in the circuit diagram of Fig. 3 is set. The control pressure Pt, which is shown in the circuit diagram of Fig. When 6 is set to a value greater than zero, it is present at the control line connections of the third and fourth switching directional valves ZW3 and ZW4. This has the consequence, on the one hand, that the control line connection of the central second adjusting element E Z,2 due to the switching of the third switching directional valve ZW3, venting occurs, combined with the opening of this adjusting element, while on the other hand, at the control line connection of the central first adjusting element E Z,1Because the fourth switching directional control valve ZW4 has switched, the control pressure P is now applied, thereby blocking this adjusting element for the first cooling line 3. As a result, the spray nozzles D in the central cooling zone K are closed. Z supplied only with cooling water containing the W2 component from the second cooling line 4.

[0043] The reduction in cooling capacity for the spray nozzles D in the central cooling zone K, as just explained Z a control pressure Pt greater than zero is shown in the circuit diagram by Fig. 6 is explained by way of example with a control pressure that corresponds to the circuit diagram of Fig. 3 corresponds to (P1 < P < P2). Similarly, the cooling capacity for the spray nozzles D in the central cooling zone K can be determined. Z The control pressure Pt can also be adjusted if the control pressure P is as shown in the circuit diagrams of the Fig. 1, Fig. 2 or Fig. 4 is shown selected.

[0044] Opening the adjusting elements or resetting the switching valves to their initial position is easily achieved by selecting a control pressure Px greater than zero, so that switching the 3 / 2-way valve 9 – as in Fig. 1 shown - the control pressure line 5 is vented.

[0045] A comparison of the values ​​for the control pressure P in the circuit diagrams of the Fig. Figure 1-5 illustrates that with the present invention it is possible, by continuously increasing the control pressure P, to adjust spray nozzles D in certain cooling zones from an edge of the segment 2 towards its center either to a reduced coolant supply, or even to completely block the coolant supply to spray nozzles D in certain cooling zones.

[0046] The control of the spray nozzles D in individual cooling zones K iAs explained, on segment 2, changes can be made by altering the control pressure P in control pressure line 5 or the control pressure Pt in auxiliary control pressure line 6, without requiring a separate control pressure loop for each cooling zone. This simplifies the control of the respective cooling zones with their associated switching elements.

Claims

[1] Device (1) for controlled secondary cooling of a metal strand guided in a strand guide device of a continuous casting plant, comprising a plurality of spray nozzles (D) provided on a segment (2) of the strand guide device and connectable via cooling lines (3, 4) to a clamping plate for connection to a distribution chamber, wherein a cooling medium can be applied to the metal strand through the spray nozzles (D), wherein different cooling zones (K) are provided by the spray nozzles (D) on the segment (2). i ) are definable and in a respective Cooling zone (K i ) at least one spray nozzle (D) is included, Adjusting devices (E i ), which are connected to the cooling lines (3, 4) for the spray nozzles (D), wherein the adjusting devices (E i ) are connected upstream of the spray nozzles (D) and the supply of cooling media to the spray nozzles (D) is controlled by the adjusting devices (E) i ) is controllable, and Switching valves (Z i , ZW i ), which are connected to a respective control line connection of the adjusting devices (E i ) are assigned and can be subjected to an adjustable control pressure (P, Pt), so that the adjusting elements (E i ) depending on the control pressure (P, Pt) for the switching valves (Z) i , ZW i ) are switchable, characterized by , that the switching valves (Z i , ZW i ) connected to a common control pressure line (5) and switchable depending on variable pressure values ​​for the control pressure (P, Pt) in order to control the adjusting devices (E i ) to open or close and thereby supply cooling media to the spray nozzles (D) in the respective cooling zones (K i ) to control. [2] Device (1) according to claim 1, characterized by , that two cooling lines (3, 4) supply the spray nozzles (D) in a respective cooling zone (K i) provided with cooling medium and each cooling zone (K II , K III , K Z ) each two adjusting elements (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) are assigned, wherein one of the adjusting devices is connected to one cooling line and the other of the adjusting devices is connected to the other cooling line, wherein of the adjusting devices (E i ) each a common supply line (V i ) to a respective cooling zone (E i ) leads. [3] Device (1) for controlled secondary cooling of a metal strand guided in a strand guide device of a continuous casting plant, comprising at least one spray nozzle (D) provided on a segment (2) of the strand guide device and connectable to a clamping plate for connection to a distribution chamber via at least one cooling line (3, 4), wherein a cooling medium can be applied to the metal strand through the spray nozzle (D), wherein at least one cooling zone (K) is provided by the spray nozzle (D) on the segment (2). i ) definable, Adjusting devices (E i ), which are connected to the cooling line (3, 4) for the spray nozzle (D), wherein the adjusting elements (E i ) are connected upstream of the spray nozzle (D) and the supply of cooling media to the spray nozzle (D) is controlled by the adjusting elements (E i ) is controllable, and Switching valves (Z i , ZW i ), which are connected to a respective control line connection of the adjusting devices (E i ) are assigned and can be subjected to an adjustable control pressure (P, Pt), so that the adjusting elements (E i) depending on the control pressure (P, Pt) for the switching valves (Z) i , ZW i ), are switchable, characterized by , that two cooling lines (3, 4) are provided for supplying the spray nozzle (D) with cooling medium and the spray nozzle (D) has two adjusting devices (E) II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) are assigned, wherein one of the adjusting devices is connected to one cooling line and the other of the adjusting devices is connected to the other cooling line, wherein of the adjusting devices (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) each a common supply line (V i ) leads to the spray nozzle (D). [4] Device (1) according to claim 3, characterized by , that the switching valves (Z i , ZW i ) are connected to a common control pressure line (5), wherein the switching valves (Z i , ZW i) are switchable depending on variable pressure values ​​for the control pressure (P) in order to control the adjusting elements (E i ) to open or close and thereby control the supply of cooling media to the spray nozzle (D). [5] Device (1) according to any one of claims 2 to 4, characterized by , that the two adjusting devices (E II,1 , E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ), which are assigned to a respective spray nozzle (D), can be controlled independently of each other, so that either both adjusting elements are open or closed, or one of the two adjusting elements is open and the other of the two adjusting elements is closed. [6] Device (1) according to any one of claims 3 to 5, characterized by, that a plurality of spray nozzles (D) are arranged on the segment (2) of the strand guide device, each of which can be connected to the clamping plate via the two cooling lines (3, 4), wherein the spray nozzles (D) on the segment (2) provide different cooling zones (K) i ) are definable. [7] Device (1) according to any one of claims 1 to 3 or according to claim 6, characterized by , that the cooling zones (K i ) are arranged on the segment (2) over its width (B). [8] Device (1) according to claim 7, characterized by , that the adjusting devices are controlled by means of the switching valves (Z i , ZW i ) can be controlled in such a way that the coolant supply for the spray nozzles (D) in the respective cooling zones (K) i ) by increasing the control pressure (P, Pt) in the control pressure line, either reduced or blocked, preferably by increasing the coolant supply to the spray nozzles (D) in the respective cooling zones (K i) is successively reduced or blocked from an edge area of ​​the segment (2) towards the center of the segment (2). [9] Device (1) according to claim 8, characterized by , that with at least one spray nozzle (D) a first cooling zone (K) is located at the edge of the segment (2) I ) is defined, wherein the spray nozzle (D) is located in the first cooling zone (K I ) a first adjusting element (E I ) is assigned, which is connected to at least one of the two cooling lines (3, 4), with the control line connection of the first adjusting device (E I ) a first switching valve (Z1) is connected upstream, which is arranged in the common control pressure line (5) and switches on from a predetermined first pressure value (P1) for the control pressure (P), wherein, if the control pressure exceeds the predetermined first pressure value (P), the first adjusting element (E I ) closes. [10] Device (1) according to claim 9, characterized by, that with at least one spray nozzle (D) on the segment (2) adjacent to the first cooling zone (K I ) towards the center of the segment (2) a second cooling zone (K II ) is defined, wherein the spray nozzle (D) is located in the second cooling zone (K II ) a pair of adjusting elements in the form of a second adjusting element (E II,1 ) and a third adjusting organ (E II,2 ) are assigned, each of which is connected to one of the two cooling lines (3, 4), with the control line connection of the second adjusting device (E II,1 ) is connected to the output of the first switching valve (Z1), with the control line connection of the third adjusting device (E II,2) a spring-loaded first switching directional control valve (ZW1) is arranged in the common control pressure line (5), which is open in its initial position and switches the control pressure line (5) through, so that when the control pressure in the control pressure line is greater than zero the second adjusting element (E II,1 ) closes, wherein the control line connection of the first switching directional control valve (ZW1) is connected in parallel to the output of the first switching valve (Z1), wherein, if the control pressure (P) in the control pressure line (5) exceeds the predetermined first pressure value (P1), the second adjusting element (E II,1 ) closes and the control pressure (P) is applied to the control line connection of the first switching directional valve (ZW1), so that by switching the first switching directional valve (ZW1) accordingly, the control line connection of the third adjusting device (E) II,2 ) is vented and thereby the third adjusting element (E) II,2 ) reopens. [11] Device (1) according to claim 10, characterized by , that with at least one spray nozzle (D) on the segment (2) adjacent to the second cooling zone (K II ) towards the center of the segment (2) a third cooling zone (K III ) is defined, wherein the spray nozzle (D) is located in the third cooling zone (K III ) a pair of adjusting elements in the form of a fourth adjusting element (E III,1 ) and a fifth adjusting organ (E III,2 ) are assigned, each of which is connected to one of the two cooling lines (3, 4), with the control line connection of the fourth adjusting device (E III,1 ) a second switching valve (Z2) is connected upstream, which is arranged in the common control pressure line (5) and switches on from a predetermined second pressure value (P2) for the control pressure (P), wherein the control line connection of the fifth adjusting device (E III,2) a spring-loaded second switching directional control valve (ZW2) is arranged upstream in the common control pressure line (5), which is open in its initial position and switches the control pressure line (5) through, so that when the control pressure (P) in the control pressure line (5) is greater than zero, the fifth adjusting element (E) III,2 ) closes, wherein the control line connection of the second switching directional valve (ZW2) is connected in parallel to the output of the second switching valve (Z2), wherein, if the control pressure (P) in the common control pressure line (5) exceeds the predetermined second pressure value (P2), the fourth adjusting element (E) III,1 ) closes and the control pressure (P) is applied to the control line connection of the second switching directional valve (ZW2), so that by switching the second switching directional valve (ZW2) accordingly, the control line connection of the third adjusting device (E) II,2 ) is vented, thereby discharging the fifth adjusting element (E) III,2) reopens. [12] Device (1) according to claim 11, characterized by , that the control line connection of the third adjusting device (E II,2 ) is connected via a first changeover valve (WV1) in parallel to the output of the second switching valve (Z2), so that the control pressure (P) is also applied to the control line connection of the third adjusting device (E) when the predetermined second pressure value is exceeded. II,2 ) is located and thereby the third adjusting element (E II,2 ) closes. [13] Device (1) according to claim 11 or 12, characterized by , that with at least one spray nozzle (D) on the segment (2) adjacent to the third cooling zone (K III ) towards a center of the segment (2) a central cooling zone (K Z ) is defined, which is essentially located in a central area of ​​the segment (2), with the spray nozzle (D) in the central cooling zone (K) Z) a pair of adjusting organs in the form of a central first adjusting organ (E Z,1 ) and a central second adjusting organ (E Z,2 ) are assigned, each of which is connected to one of the two cooling lines (3, 4), with the control line connection of the central first adjusting device (E Z,1 ) a third switching valve (Z3) is connected upstream, which is arranged in the common control pressure line (5) and switches on from a predetermined third pressure value (P3) for the control pressure (P), wherein the control line connection of the central second adjusting device (E Z,2 ) a spring-loaded third switching directional control valve (ZW3) is arranged upstream in the common control pressure line (5), which is open in its initial position and switches the control pressure line (5) through, so that when the control pressure (P) in the control pressure line (5) is greater than zero, the central second adjusting element (E) Z,2) closes, whereby, if the control pressure (P) in the common control pressure line (5) exceeds the predetermined third pressure value (P3), the central first adjusting element (E) Z,1 ) closes. [14] Device (1) according to claim 13, characterized by , that the control line connection of the fifth adjusting device (E III,2 ) is connected via a second changeover valve (WV2) in parallel to the output of the third switching valve (Z3), so that the control pressure (P) is also applied to the control line connection of the fifth adjusting element (E) when the predetermined third pressure value (P3) is exceeded. III,2 ) is located and thereby the fifth adjusting element (E III,2 ) closes. [15] Device (1) according to claim 13 or 14, characterized by , that in the control pressure line (5) between the control line connection of the central first adjusting device (E Z,1) and the third switching valve (Z3), a spring-loaded fourth switching directional valve (ZW4) is arranged, which is open in its initial position and switches the control pressure line (5), wherein a control line port of the third switching directional valve (ZW3) and a control line port of the fourth switching directional valve (ZW4) are connected in parallel to an auxiliary control pressure line (6), wherein at an auxiliary control pressure (Pt) of greater than zero the third and fourth switching directional valves (ZW3, ZW4) are switched respectively, wherein if the auxiliary control pressure (Pt) assumes a value greater than zero, the control line port of the central first adjustment stage (E Z,1 ) connected to the control pressure line (5) and remains closed accordingly, and the control line connection of the central second adjustment circuit (E Z,2 ) is vented and thereby the central second adjusting element (E) Z,2 ) reopens. [16] Device (1) according to any one of claims 2 to 15, characterized by , that all adjusting devices (E i ) are spring-loaded and the control pressure line (5) is ventable, whereby when the control pressure line (5) is vented all adjusting elements (E i ) return to their open starting position, so that cooling medium flows through both cooling lines (3, 4) to the spray nozzles (D) in all cooling zones (K i ) is supplied. [17] Device (1) according to claim 16, characterized by, that a spring-loaded 3 / 2-way valve (9) is arranged in the control pressure line, at whose control line connection a reset pressure (Px) can be applied, wherein at a reset pressure (Px) of zero the 3 / 2-way valve (9) is in an open default position and the control pressure line (5) switches open, wherein at a reset pressure (Px) greater than zero the 3 / 2-way valve (9) blocks flow in the control pressure line (5) and opens the control pressure line (5) to the environment, so that the control pressure line (5) is vented and thereby the adjusting elements (E) i ) return to their respective open starting positions. [18] Device (1) according to any one of claims 9 to 17, characterized by , that the first, second and / or third cooling zone (K I , K II , K III ) are arranged in pairs and symmetrically to the center of segment (2) on segment (2), with each of the two cooling zones of these pairs being connected by a supply line (V)I ; V II ; V III ) are connected to the associated adjusting mechanisms. [19] Device (1) according to any one of claims 1 to 18, characterized by , that the cooling lines (3, 4) are arranged on the segment (2). [20] Device (1) according to any one of claims 1 to 19, characterized by , that the switching valves are integrated in a structural unit in the form of a valve manifold (7, 8). [21] Device (1) according to any one of claims 1 to 20, characterized by , that the switching valves (Z i , ZW i ) together with the adjusting mechanisms (E i ) are arranged on segment (2). [22] Device (1) according to any one of claims 1 to 21, characterized by , that the adjusting mechanisms (E i ) are each designed as a 2 / 2-way valve, and / or that the auxiliary directional valves (ADP) i ) are each designed as 3 / 2-way valves. [23] Method for controlled secondary cooling of a metal strand guided in a strand guide device of a continuous casting plant, in which a plurality of spray nozzles (D) are provided on a segment (2) of the strand guide device, which are supplied with cooling medium from a distribution chamber via cooling lines (3, 4), wherein the spray nozzles (D) on the segment (2) provide different cooling zones (K i ) are definable and in a respective cooling zone (K i ) includes at least one spray nozzle (D), wherein the spray nozzles (D) of the respective cooling zones (K i ) switchable adjusting devices arranged in the cooling lines (3, 4) (E i ) are upstream, with switching valves (Z i , ZW i ) a respective control line connection of the adjusting devices (E i ) are assigned and are subjected to an adjustable control pressure (P) to control the adjusting elements (E i) depending on the control pressure (P, Pt) for the switching valves (Z) i , ZW i ) to switch, characterized by , that the control pressure (P) is applied to the switching valves (Z) i , ZW i ) is applied through a common control pressure line (5), wherein the switching valves (Z i , ZW i ) are switched by changing the control pressure (P) to control the adjusting elements (E i ) to open or close and thereby supply cooling media to the spray nozzles (D) in the respective cooling zones (K i ) to control. [24] Method according to claim 23, characterized by , that the coolant is supplied through two cooling lines (3, 4) to the spray nozzles (D) in a respective cooling zone (K i ) is supplied and each cooling zone has two adjustment devices (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2) are assigned, wherein one of the adjusting devices is connected to one cooling line and the other of the adjusting devices is connected to the other cooling line, wherein of the adjusting devices (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) each a common supply line (V i ) to the spray nozzles (D) in a respective cooling zone (K i ) leads. [25] Method for controlled secondary cooling of a metal strand guided in a strand guide device of a continuous casting plant, in which at least one spray nozzle (D) is provided on a segment (2) of the strand guide device, which is supplied with cooling medium from a distribution chamber via at least one cooling line (3, 4), wherein at least one cooling zone (K) is provided with the spray nozzle (D) on the segment (2). i ) is definable, wherein the spray nozzle (D) is equipped with switchable adjusting elements (E) arranged in the cooling line. i) are upstream, with switching valves (Z i , ZW i ) a respective control line connection of the adjusting devices (E i ) are assigned and are subjected to an adjustable control pressure (P) to control the adjusting elements (E i ) depending on the control pressure (P, Pt) for the switching valves (Z) i , ZW i ) to switch, characterized by , that at least one spray nozzle (D) is located in the cooling zone (K II ; K II , ; K Z ) is supplied with coolant through two cooling lines (3, 4) and the cooling zone (K II ; K II , ; K Z ) two adjusting devices (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) are assigned, wherein one of the adjusting devices is connected to one cooling line and the other of the adjusting devices is connected to the other cooling line, wherein the adjusting devices have a common supply line (V I ; V II; V III ) to the spray nozzle (D) in the cooling zone (K i ) leads. [26] Method according to claim 25, characterized by , that a plurality of spray nozzles (D) are provided on the segment (2), wherein the spray nozzles (D) on the segment (2) provide a plurality of different cooling zones (K) i ) are defined, each of which has two adjusting elements (E II,1, E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ) are assigned, wherein one of the adjusting devices is connected to one cooling line and the other of the adjusting devices is connected to the other cooling line, wherein of the adjusting devices (E i ) each a common supply line (V II ; V III ; V Z ) to the spray nozzles (D) in a respective cooling zone. [27] Method according to claim 23, 24 or 26, characterized by , that the majority of cooling zones (K i) are arranged over the width (B) of the segment (2), wherein an increase in the control pressure (P) provides coolant to the spray nozzles (D) in the respective cooling zones (K) i ) is successively reduced or blocked from an edge of segment (2) towards the center of segment (2). [28] Method according to any one of claims 24 to 27, characterized by , that the two adjusting devices (E II,1 , E II,2 ; E III,1 , E III,2 ; E Z,1 , E Z,2 ), which are assigned to the spray nozzles in a respective cooling zone, are controlled independently of each other, so that either both adjusting devices are open or closed, or one of the two adjusting devices is open and the other of the two adjusting devices is closed.

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