COOLANT NOZZLE FOR COOLING A METAL STRAND IN A CONTINUOUS CASTING INSTALLATION

Abstract

A coolant nozzle (1) for cooling a metal strand in a continuous casting installation has a mouthpiece (5), which is arranged at a nozzle outlet end (4) and through which liquid coolant (6) can emerge from the coolant nozzle (1). To allow a rapid buildup of pressure at the coolant nozzle (1), it provides a feed (8), which is formed as a tube-in-tube system (9) arranged upstream of the mouthpiece (5) in the direction of through-flow (7) and has a feed outlet end (10), through the first tube (11) in which control air (13) can be brought up to the feed outlet end (10) and through the second tube (12) of which the liquid coolant (6) can be fed to the mouthpiece (5) by way of the feed outlet end (10), and also provides a control valve (14), which is integrated in the feed (8), is arranged at the feed outlet end (10), can be actuated pneumatically by using the control air (13) and is intended for controlling the feed of the liquid coolant (6) into the mouthpiece (5).

Claims

1. A coolant nozzle for cooling a metallic strand in a continuous casting plant, comprising: a mouthpiece which is disposed on a nozzle exit end and through which liquid coolant from the coolant nozzle can exit; an infeed configured as a tube-in-tube system comprising; a first tube which is an inner tube for the control air, and a second tube which is an outer tube, disposed substantially concentric with the inner tube and is for the liquid coolant; in a throughflow direction, the infeed is disposed ahead of the mouthpiece, and the infeed has an infeed exit end, toward which control air is capable of being guided to the infeed exit end through the first tube of the infeed, and the liquid coolant is capable of being fed in the throughflow direction through the second tube of the infeed and then into the mouthpiece via the infeed exit end; a switchover valve which is integrated in the infeed, is disposed on the infeed exit end, and is pneumatically activatable while using the control air, the switchover valve having a switching element which is a control piston; and the switchover valve comprises a seat valve, the switchover valve is configured and operable for controlling the feeding of the liquid coolant into the mouthpiece, and the valve is either opened or closed as a function of the position of the switching element.

2. (canceled)

3. The coolant nozzle as claimed in claim 1, further comprising at least one of the first tube and/or the second tube are/is configured of multiple parts, in particular are/is configured in multiple parts in such a manner that the parts thereof are capable of being screw-fitted or welded to one another.

4. (canceled)

5. The coolant nozzle as claimed in claim 1, further comprising a bellows configured and operable and seal the switching element and including the control piston.

6. The coolant nozzle as claimed in claim 5, further comprising the bellows is disposed concentric with and on the inner tube, and the bellows is disposed on a second part of the inner tube that is configured as a bellows detent and the bellows is configured and operable to be guided axially relative to the inner tube relative to the bellows detent.

7. The coolant nozzle as claimed claim 1, further comprising the mouthpiece is configured to be releasably connected to the coolant nozzle.

8. The coolant nozzle as claimed in claim 1, further comprising the infeed exit end is configured as a mouthpiece receptacle to which the mouthpiece is screw-fittable.

9. The coolant nozzle as claimed in claim 8, further comprising the infeed exit end is configured as a valve seat for the switching element of the switchover valve, and the switchover valve includes, the control piston of the seat valve.

10. The coolant nozzle as claimed in claim 9, further comprising a material of the switching element including the control piston, and a material of the valve seat are mutually adapted, such that the valve seat has one of a lesser hardness than the switching element, or the valve seat has another greater hardness than the switching element, wherein the part having the lesser hardness is annealed.

11. The coolant nozzle as claimed in claim 1, further comprising a connector block which is screw-fittable to the infeed and which has a first connector for the control air and/or a second connector for the liquid coolant.

12. The coolant nozzle as claimed in claim 11, further comprising the connector block has a first conduit, the first connector being connectable to the first inner tube of the infeed while using the first conduit.

13. The coolant nozzle as claimed in claim 1, further comprising the infeed is configured to be rectilinear, or bent, having at least one bend.

14. The coolant nozzle as claimed in claim 1, further comprising the control air is an instrument air.

15. A cooling installation for cooling a metallic strand in a continuous casting plant comprising: a plurality of nozzle units which are disposed in succession in a strand conveying direction to extend transversely to the strand conveying direction, each of the nozzle units having at least one first coolant nozzle, and at least one second coolant nozzle, wherein the first and second coolant nozzles are as claimed in claim 1.

16. The cooling installation as claimed in claim 15, further comprising the first coolant nozzles of the plurality of nozzle units are configured for being supplied with the control air by a first common control air infeed; the second coolant nozzles of the plurality of nozzle units are configured for being supplied with the control air by a second common control air infeed.

17. The cooling installation as claimed in claim 16, further comprising a first control valve for the control air supply in the first common control air infeed that is disposed in the first common control air infeed; and a second control valve for the control air supply in the second common control air infeed that is disposed in the second common control air infeed.

18. A continuous casting plant having a cooling installation as claimed in claim 15.

19. The coolant nozzle as claimed in claim 12, further comprising the connector block has a second conduit, wherein the second connector is connectable to the second tube of the infeed while using the second conduit.

20. The coolant nozzle as claimed in claim 13, wherein having at least one bend along a length thereof.

21. The coolant nozzle as claimed in claim 6, wherein the bellows is a corrugated bellows.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] In the drawings:

[0081] FIG. 1 shows a schematic illustration of a continuous casting plant having a cooling installation;

[0082] FIG. 2 shows a schematic section through the continuous casting plant from FIG. 1, along the sectional plane II-II therein;

[0083] FIG. 3 shows a pneumatically actuatable coolant nozzle for a nozzle unit of a cooling installation of the continuous casting plant from FIG. 1;

[0084] FIG. 4 shows the pneumatically actuatable coolant nozzle for a nozzle unit of a cooling installation of the continuous casting plant from FIG. 1 having a bent infeed; and

[0085] FIG. 5 shows a schematic view of a further cooling installation for a cooling zone for the continuous casting plant from FIG. 1.

DESCRIPTION OF EMBODIMENTS

[0086] FIG. 1 shows a continuous casting plant 3 in a schematic illustration. The continuous casting plant 3 can be, for example, a plant for casting steel slabs.

[0087] The continuous casting plant 3 comprises inter alia a ladle 30 having an outlet tube 31. The plant 3 further comprises a casting distributor 32 which is disposed below the ladle 30 and which has a casting tube 33 as well as a plug 34 that is disposed in the casting distributor 32.

[0088] The continuous casting plant 3 comprises a permanent mold 35 which has four water-cooled permanent plates 36 from copper, and has a rectangular cross-sectional shape. Only two of the four permanent mold plates 36 are visible in FIG. 1.

[0089] The plant 3 a moreover comprises a plurality of driven transport rollers 37 which form elements of a strand guide of the continuous casting plant 3.

[0090] The plant 3 has a post-connected apparatus, for example, a flame cutting machine, which is not illustrated in the figure.

[0091] Liquid steel 38 situated in the ladle 30 is directed into the casting distributor 32 from the outlet tube 31. The liquid steel 38 from the casting distributor 32 is in turn directed into the permanent mold 35 by way of the casting tube 33, so that a mass flow of the steel 38 flowing into the permanent mold 35 is controlled with the aid of the plug 34.

[0092] The steel 38 on the contact faces of the water-cooled permanent mold plates 36 cools in the permanent mold 35 and solidifies therein such that the steel 38, then in the form of a strand 2 having a rectangular cross section, exits the permanent mold 35.

[0093] When exiting the permanent mold 35, the strand 2 has a solidified shell of several millimeters thickness, while a majority of the cross section of the strand 2 is still liquid. The surface temperature of said strand 2 herein is intended to be at a magnitude of approximately 1000 C.

[0094] The strand 2 exiting the permanent mold 35 is transported away from the mold 35 with the aid of the transport rollers 37 and is guided to the post-connected apparatus mentioned earlier (not illustrated in the Figures). By means of the post-connected apparatus, this strand is cut to form slabs, for example, and is subsequently transported away. Alternatively, the strand 2 could be processed directly by another post-connected apparatus, for example a roll stand of a casting/rolling composite plant, without first being divided into slabs.

[0095] The continuous casting plant 3 furthermore has a cooling installation 50 for cooling the strand 2.

[0096] The cooling installation 50 for cooling the strand 2 from a first side (an upper side in the drawing) comprises a preferred number of sixteen nozzle units 40 that are disposed in succession in the strand conveying direction 51. Another of those 16 nozzle units 40, four nozzle units 40 in succession in the strand conveying direction 51 are each part of a common cooling zone 39 of the cooling installation 50. The sixteen nozzle units 40 are divided into four cooling zones 39 having in each case four nozzle units 40 (See also FIG. 5).

[0097] According to FIG. 1, each cooling zone 39 is assigned a dedicated coolant pump 54, a main coolant supply line 55 which is connected to the coolant pump 54 of the cooling zone 39 and from which four individual coolant supply lines 56 branch off. Each coolant supply line 56 is connected to one of the nozzle units 40. However, a single coolant pump, by a main infeed, usually supplies a plurality of cooling zones with coolant. The branching of the coolant, the setting of the pressure or of the throughflow in the individual coolant supply lines 56 of the cooling zones is performed by control valves, for example.

[0098] Each of the nozzle units 40 has a row of a plurality of cooling nozzles 1 that in succession, the row extending perpendicular to the strand conveying direction 51, transverse to the strand conveying direction 52 (See FIG. 2).

[0099] Moreover, the coolant nozzles 1 in the present exemplary embodiment have in each case one switchover valve 14 which is integrated in the respective coolant nozzle 1 and is pneumatically controllable by control air 13, presently instrument air (see FIG. 3).

[0100] The cooling installation 50 furthermore has a control unit 47, by which the switchover valves 14 are controllable/switchable (see FIG. 5)).

[0101] Moreover, the cooling installation 50, for cooling the strand 2 from a second side, the lower side in FIG. 1, opposite the first side, comprises sixteen nozzle units 40 disposed in succession in the strand conveying direction 51. These nozzle units 40 each also have one switchover valve 14 that is pneumatically switchable/activatable by the control unit 47 (See FIG. 3).

[0102] Of the last-mentioned sixteen nozzle units 40, four nozzle units 40 in succession in the strand conveying direction 51 are each part of a common cooling zone (See also FIG. 5).

[0103] Each of the cooling zones also has a dedicated coolant pump, a main coolant supply line which is connected to the coolant pump of the cooling zone and from which four individual coolant supply lines branch off. These elements are not illustrated in the Figures for improving clarity.

[0104] The number of the nozzle units 40 per strand side, in the present case sixteen, and the numerical distribution of said nozzle units 40 among a plurality of cooling zones 39, in the present case four cooling zones 39 per strand side, is chosen as exemplifies. The continuous casting plant 3 could in principle have a different number of nozzle units 40 and/or a different number of cooling zones 39.

[0105] Moreover, the cooling installation 50 may comprise a temperature measuring installation (not illustrated), for example a pyrometer, for measuring a surface temperature of the strand 2 in a non-contacting manner. The temperature measuring installation can be connected to the control unit 47 by a data line. A temperature measurement is however not strictly necessary. Alternatively to the temperature measuring installation, the cooling installation 50 may comprise a cooling model (See DYNACS) which calculates the required water quantities in the cooling zones in real time without measurement of the temperatures.

[0106] In principle, the cooling installation 50 can have a plurality of such temperature measuring installations. For example, at least one temperature measuring installation may be provided on the first side of the strand 2 and on the second side of the strand 2.

[0107] While the strand 2 is transported away to the post-connected apparatus, the nozzle units 40, and more specifically the coolant nozzles 1, spray a coolant 6 onto the strand surface 57. The strand 2 is cooled in this manner and that increasingly solidifies in the strand conveying direction 51. The coolant 6 in the present case is water.

[0108] Each of the nozzle units 40 applies a predefined/adjustable quantity of coolant to the strand surface 57. The quantity is controlled, in terms of quantity and time by the switchover valve 14 of the respective coolant nozzle 1.

[0109] The temperature measuring installation measures a surface temperature of the strand 2 and transmits the measured surface temperature to the control unit 47. As a function of the determined surface temperature and of a predefined surface temperature nominal value, by the switchover valves 14, the control unit 47 controls the coolant quantities applied by the coolant nozzles 1 to the strand 2 so that the surface temperature of the strand 2 corresponds to the predefined surface temperature nominal value, or approximates the latter.

[0110] The nozzle units 40 on the second side (the lower side in terms of the drawing) of the strand 2, or the coolant nozzles thereon, respectively, are operated in a like manner.

[0111] Moreover, a vertical sectional plane II-II which in the end region of the strand guide runs perpendicularly to the strand conveying direction 51 through the continuous casting plant 3 is illustrated in FIG. 1.

[0112] FIG. 2 shows a schematic section through the continuous casting plant 3 from FIG. 1, along the sectional plane II-II therein.

[0113] The strand 2 and, in an example, one of the nozzle units 40 is illustrated in FIG. 2.

[0114] The illustrated nozzle unit 40 has a row of a plurality of, for example, five coolant nozzles 1 that are disposed in succession perpendicularly or transverse to the strand conveying direction 51. The nozzle unit 40 can also be referred to as a spray beam 40), wherein the strand conveying direction 51 in the region of the nozzle unit 40 illustrated is perpendicular to the drawing plane of FIG. 2.

[0115] The coolant 6 exits the coolant nozzles 1 in the form of cones or coolant cones. Their form is determinable by way of the mouthpiece 5 of the respective coolant nozzle 1 (See FIG. 3)). In the present case, the coolant cones contact one another on the strand surface 57. It is also possible for the coolant cones to overlap one another.

[0116] It can furthermore be seen that the nozzle unit 40 illustrated for the five coolant nozzles 1 thereof, or for the respective pneumatically controllable switchover valve 14 thereof (See FIG. 3), respectively, has a common control air infeed 43, presently instrument air, having a common pilot control valve 45. Application of coolant to the strand surface 57 for the five coolant nozzles 1 in a row is collectively controllable. The coolant 6 herein is fed to the coolant nozzles 1 by the individual coolant supply line 56.

[0117] FIG. 3 shows the pneumatically controllable coolant nozzle 1 in detail.

[0118] The coolant nozzle 1 has three main components or modules, disposed one behind the other in the throughflow direction 7 including a connector block 17 disposed on the nozzle entry end, an infeed 8 forming the central part 65 of the coolant nozzle 1, and a mouthpiece 5 disposed on the nozzle exit end 4.

[0119] Screw-fittings 21 capable of being screw-fitted to one another in pressure-tight manner are capable of easy assembly/disassembly and replacement. Welding-capable connections are suitable as an alternative to screw fittings 21.

[0120] The connector block 17 connects the coolant nozzle 1 to the common control air infeed 43, see FIG. 5 for the control air 13 for activating switching the coolant nozzle 1) and to the individual coolant supply line 56 (for the coolant 6 for cooling the strand) (See FIG. 1).

[0121] To this end, the connector block 17 comprises a first connector 24 which runs perpendicularly to the throughflow direction 7 of the control air 13 through the coolant nozzle 1. The connector block 17 is connected to the common control air infeed 43 so as to be sealed by a seal 22 comprising an O-ring. The control air 13, thus enters the connector block 17 perpendicular to the throughflow direction 7 by the first connector 24, in the connector block 17, the control air is guided by a first conduit 26 and here is also deflected to the throughflow direction 7, and flows into a first part 11a of an inner first tube 11 of the infeed 8. The inner first tube 11 is configured in two parts, the infeed 8 as a tube-in-tube system 9 configured from the two-part inner first tube 11, 11a, 11b, and a two-part outer second tube 12, 12a, 12b.

[0122] To this end, said first part 11a of the inner tube 11 of the infeed 8 is plug-fitted into a bore 58 of the connector block 17. That bore 58 runs in the throughflow direction 7 and is sealed by means of an O-ring 22.

[0123] The connector block 17 furthermore provides a second connector 25 which runs perpendicularly to the throughflow direction 7 of the coolant 6 through the coolant nozzle 1 which connects the connector block 17 to the individual coolant supply line 56 so as to be sealed by means of a seal 22, presently likewise an O-ring 22. The coolant 6, thus enters the connector block 17 by way of the second connector 25 perpendicular to the throughflow direction 7. In the connector block 17, the coolant is guided by a second conduit 27 and the coolant is also deflected to the throughflow direction 7, and flows into the first part 12a of the outer second tube 12 of the infeed 8 that is configured as a tube-in-tube system 9.

[0124] The outer second tube 12 is configured in two parts. To this end, the first part 12a of the outer (second) tube 12 of the infeed 8 is plug-fitted into a bore 58 of the connector block 17. That bore 58 runs in the throughflow direction 7, and is screw-fitted by an external thread on the first part 12a of the outer (second) tube and an internal thread on the bore 58.

[0125] The control air 13 and the coolant 6 can initially enter into the connector block 17 which, on account of the above, is of a very compact construction. The air and coolant are deflected to the throughflow direction 7 in the connector block 17, and can exit the connector block 17 again in the throughflow direction 7, and in a pressure tight manner, they can flow from the infeed 8 into the infeed 8 at the latter by way of the infeed entry end 66 thereof.

[0126] The infeed 8 is configured as a concentric tube-in-tube system 9 comprised of the two-parts of an inner first tube 11 having the two part-tubes 11a and 11b, and the two-part outer tube 12 which has the two part-tubes 12a, 12b and is disposed concentric with the inner tube 11.

[0127] The control air 13 is guided by the inner tube 11, 11a, 11b, to the switchover valve 14, which is presently shown as a seat valve, that is disposed in the infeed 8 at the infeed exit end 10. The coolant 6 is directed by the outer tube 12, 12a, 12b into the mouthpiece 5 by the infeed exit end 10 of the infeed 8. The mouthpiece 5 is screw-fitted to the infeed 8 at the infeed exit end 10 of the latter.

[0128] Because of the constructive design of the tube-in tube-system 9 at the infeed 8, the coolant nozzle enables the control air 13 and the coolant 6 to be brought to close behind the nozzle exit end 4, or up to the mouthpiece 5.

[0129] The spray pattern of the coolant nozzle 1, for example as the coolant cone, can be determined by the design of the mouthpiece exit opening 67.

[0130] The two part-tubes 11a and 11b, and 12a and 12b, respectively, of the inner tube 11 and the outer tube 12 are in each case screw-fitted to one another in a pressure-tight manner (21). Additionally, the first and the second part-tube 11a and 11b of the inner tube 11 are also adhesively bonded or welded to one another, respectively.

[0131] As is shown in FIG. 3, the switchover valve 14 which is pneumatically activatable/switchable by the control air 13 and which is configured as a seat valve, having a switching element 15 that is configured as a control piston 15 (switchable by the control air 13) sits on the infeed exit end 10. The switchover valve 15 blocking the coolant outflow from the outer tube 12, or from the second part 12b of the outer tube 12 of the infeed 8, respectively. The control piston 15 herein by the control air 13 is pushed out of the inner tube 11 into the valve seat 20 of the seat valve 14), or releases the coolant flow.

[0132] To this end, the switchover valve/seat valve 14 provides that by means of a (corrugated) bellows 16, preferably from steel, the control piston 15 is guided in the throughflow direction 7, as in the case of a linear guide in an axial/linear manner and sealed in relation to the infeed 8, that is presently the inner tube 11, or the second part 11b of the inner tube 11, respectively.

[0133] To this end, the corrugated bellows 16, by way of an interference fit sits concentric on the second part 11b of the inner tube 11. The second part 11b provides a corrugated bellows detent 18 for a sleeve 69 that supports a corrugated bellows support 19 and that supports the corrugated bellows 16.

[0134] By way of a front end 70 of the sleeve 69 up to the corrugated bellows detent 18, the sleeve 69 in a pressure-tight manner is screw-fitted and adhesively bonded to the second part 11b of the inner tube 11. A shoulder 72 of the (corrugated) bellows support 19 is supported on the rear end 71 of the sleeve 69.

[0135] By way of the first end thereof in the throughflow direction 7, the corrugated bellows 16 is placed in a pressure-tight manner onto that end of the corrugated bellows support 19 that is opposite the shoulder 72. By way of the second end in the throughflow direction 7, the corrugated bellows 16 is placed in a pressure tight manner onto the control piston 15, which in the throughflow direction 7 is thus disposed directly ahead of the exit end 73 of the second part 11b of the inner tube 11.

[0136] When the control air 13 now exits through exit end 73 of the second part 11b of the inner tube 11, the control air 13 axially displaces the control piston 15 in the valve seat 20 thereof, whereby the corrugated bellows 16 is stretched. Once there is no longer control air 13 or no control air pressure, respectively, bearing on the control piston 15, the corrugated bellows 16 is again contracted to its original shape, wherein the control piston 15 is again released from the valve seat 20 thereof.

[0137] The valve seat 20 is likewise a tubular component forming the infeed exit end 10 of the infeed 8. The seat 20 has a through bore 74 for the coolant 6, and by means of an outer sleeve 75. The seal is braced in a pressure-tight manner in relation to the exit end 76 of the second part 12b of the outer tube 12.

[0138] As is then furthermore shown in FIG. 3, the mouthpiece 5 is screw-fitted in a pressure-tight manner onto the valve seat 20 and thus also to a mouthpiece receptacle 20.

[0139] The material of the control piston 15 and the material of the valve seat 20 are mutually adapted in such a manner that the valve seat 20 has a lesser hardness than the control piston 15.

[0140] FIG. 4 shows the pneumatically controllable coolant nozzle 1 in a further embodiment in which the infeed 8 has a double bend 23.

[0141] The following description of the coolant nozzle 1 is primarily limited to the points of differentiation in relation to the coolant nozzle 1 described above, and to which reference is made in terms of features and functions that remain the same. See FIG. 3 and associated explanations. Substantially identical or mutually equivalent elements, respectively, are identified by the same reference signs, and features not mentioned are incorporated for the description of said coolant nozzle 1 without said features being described once again.

[0142] FIG. 4 shows the infeed bent for a first time in the inflow region of the infeed 8 by a first bending angle of approx. 20 and for a further, second, time in the outflow region by a second bending angle 60 of likewise approx. 20.

[0143] Other first and second bending angles 59, 60, different first and second bending angles 59 and 60, respectively, as well as even more bends having corresponding bending angles, can be implemented in the case of the infeed 8, depending on the specific application.

[0144] The most varied coolant nozzle designs can be implemented in a simple and extremely flexible manner the replacement of an infeed 8 is possible entirely without problems by virtue of the screw-fittable modular construction. The coolant nozzle may include dissimilarly designed bending angles 59, 60 on the infeed 8, and/or dissimilar lengths 61 of the infeed 8 per se.

[0145] The connector block 17, in FIG. 4, has an axial through bore 77 into which, or through which, the first part 11a of the inner tube 11 is push-fitted. The end 78 of the first part 11a of the inner tube 11 that protrudes from the connector block 17 is welded to the connector block 17 79.

[0146] FIG. 5 schematically shows a cooling installation 50 which in terms of the infeed of the control air 13 is more complex but is of a more flexible design so that different cooling requirements, in particular in terms of the coolant quantity, can be applied to the strand 2, or to the width thereof.

[0147] For example, outer or outlying strand regions, in the direction that is transverse to the strand conveying direction 52 thus require less cooling and a lower quantity of coolant than regions on the inside require.

[0148] The description of the cooling installation 50 having the coolant nozzles 1 is primarily limited to the point of differentiation in relation to the cooling installation 50 described above (See FIG. 1 and FIG. 2), reference in terms of features and functions that remain the same are also being made. As is expedient, substantially identical or mutually equivalent elements, are identified by the same reference signs, and features not mentioned are incorporated for the description of the cooling installation 50 without being described again.

[0149] FIG. 5 shows a cooling zone 39, which is presently illustrated, being the one symmetry aspect 68 of the cooling installation 50 that is symmetrical in relation to the strand centerline 62 comprises a total of four nozzle units 40 or spray beams 40 in the strand conveying direction 51. They have in each case eight coolant nozzles 1 arranged in the direction transverse to the strand conveying direction 52. The cooling installation 50 includes four cooling zones 39 in a manner to be symmetrical in relation to the strand centerline 62. This provides three different control zones 63a and 63b and 63c, all of which are actuatable by the control unit 47.

[0150] The outermost left and right in relation to the direction transverse to the strand conveying direction 52, first coolant nozzles 41 of the four spray beams 40 are connected by way of a first common control air infeed 43.

[0151] A first pilot control 45 is disposed in the first common control air infeed 43, as shown in FIG. 5, for example, is pneumatically controllable by the control unit 47. The left and right outermost first coolant nozzles 41 of the four spray beams 40 in the cooling zone 39 may be collectively actuated and may be activated independently of the coolant nozzles 1 of the cooling installation 50.

[0152] As is likewise highlighted in FIG. 5, each second outermost second coolant nozzles 42 of the four spray beams 40 are correspondingly connected by a (second) common control air infeed 44 having a second pilot control valve 46 disposed thereon and can thus be collectively actuated and activated by the control unit 47.

[0153] All further central (third) coolant nozzles 48, or 48a and 48b, respectively, of the four spray beams 40 are likewise connected by a (third) common control air infeed 49 having a third pilot control valve 53 disposed thereon and can thus be collectively actuated and activated by the control unit 47.

[0154] The coolant supply of the coolant nozzles 1, or 41, 42, 48, is by the main coolant supply line 55 and by individual coolant supply lines 56 (cf. FIG. 1 and FIG. 2).

[0155] The coolant nozzles 1 are typically disposed directly on a strand guiding segment between strand guiding rollers. It is therefore favorable in terms of the reliability of the control unit 47 and/or of the pilot control valves 45, 46, 53 when the control unit 47 and/or the pilot control valves 45, 46, 53 are disposed on the main body of the continuous casting plant, so as to be away from the strand guide. The control unit 47 and the pilot control valves 45, 46, 53 are thereby not exposed to high temperatures or high air humidity. On the other hand, individual pilot control valves can also be replaced in the ongoing operation of the plant without the continuous casting having to be interrupted for this purpose.

[0156] In order for the control air in the event of a segment changeover to be able to be rapidly connected or disconnected, it is advantageous for the control air from the main body having the pilot control valves 45, 46, 53 to be guided to the strand guiding segment by pneumatic quick-release couplings.

[0157] While the invention has been illustrated and described in detail by the preferred exemplary embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom without departing from the scope of protection of the invention.

LIST OF REFERENCE SIGNS

[0158] 1 Coolant nozzle

[0159] 2 (Metallic) strand

[0160] 3 Continuous casting plant

[0161] 4 Nozzle exit end

[0162] 5 Mouthpiece

[0163] 6 Coolant

[0164] 7 Throughflow direction

[0165] 8 Infeed

[0166] 9 Tube-in-tube system

[0167] 10 Infeed exit end

[0168] 11 First tube, inner tube (for control air)

[0169] 11a First part of the first/inner tube

[0170] 11b Second part of the first/inner tube

[0171] 12 Second tube, outer tube (for coolant)

[0172] 12a First part of the second/outer tube

[0173] 12b Second part of the second/outer tube

[0174] 13 Control air

[0175] 14 Switchover valve, seat valve, valve unit

[0176] 15 Switching element, control piston

[0177] 16 (Corrugated) bellows

[0178] 17 Connector block

[0179] 18 (Corrugated bellows) detent

[0180] 19 (Corrugated) bellows support

[0181] 20 Mouthpiece receptacle, valve seat

[0182] 21 Screw fitting

[0183] 21a Adhesively bonded screw fitting

[0184] 22 Seal, O-ring

[0185] 23 Bend (of (8))

[0186] 24 First connector

[0187] 25 Second connector

[0188] 26 First conduit

[0189] 27 Second conduit

[0190] 30 Ladle

[0191] 31 Outlet tube

[0192] 32 Casting distributor

[0193] 33 Casting tube

[0194] 34 Plug

[0195] 35 Permanent mold

[0196] 36 Permanent mold plate

[0197] 37 Transport roller

[0198] 38 Steel

[0199] 39 Cooling zone

[0200] 40 Nozzle unit, spray beam

[0201] 41 First coolant nozzle (1)

[0202] 42 Second coolant nozzle (1)

[0203] 43 (First) common control air infeed

[0204] 44 Second common control air infeed

[0205] 45 (First) (pilot) control valve

[0206] 46 Second (pilot) control valve

[0207] 47 Control unit

[0208] 48, 48a, 48b further (third) coolant nozzles (1)

[0209] 49 Third common control air infeed

[0210] 50 Cooling installation

[0211] 51 Strand conveying direction

[0212] 52 Direction transverse to strand conveying direction

[0213] 53 Third control valve

[0214] 54 Coolant pump

[0215] 55 Main coolant supply line

[0216] 56 Individual coolant supply line

[0217] 57 Strand surface

[0218] 58 Bore

[0219] 59 First bending angle

[0220] 60 Second bending angle

[0221] 61 Length

[0222] 62 Strand centerline

[0223] 63a (First) control zone

[0224] 63b (Second) control zone

[0225] 63c (Third) control zone

[0226] 64 Nozzle entry end

[0227] 65 Central part

[0228] 66 Infeed entry end

[0229] 67 Mouthpiece exit opening

[0230] 68 First symmetry aspect

[0231] 69 Sleeve

[0232] 70 Front end

[0233] 71 Rear end

[0234] 72 Shoulder

[0235] 73 Exit end

[0236] 74 Through bore

[0237] 75 External sleeve

[0238] 76 Exit end

[0239] 77 Through bore

[0240] 78 Protruding end

[0241] 79 Welded connection