Cooling of rolled matertial

Abstract

A cooling bar (1) for cooling rolled material (5) being moved in a transport direction (3) and in particular for reducing temperature differences in the temperature of the rolled material (5) transversely to the direction of transport (3). The cooling bar (1) has several full jet nozzles (11) by means of which a coolant beam of a coolant with an approximately constant jet diameter can be distributed to the rolling stock (5) in the direction of distribution (15). A cooling device has at least two cooling bars (1) of that type. The cooling bars extend transversely to a transport direction, one behind the other. Each cooling bar has a respective different pattern of jet nozzles and selection of applicable pattern of jet nozzles in their respective bars selectively cools the rolled material transversely to the transport direction.

Claims

1. A cooling bar for cooling rolled material which is moved in a transport direction, the cooling bar including: a spray chamber which is fillable with a coolant; a distribution chamber for intermediate storage of the coolant and which is connected to the spray chamber by at least one through opening for filling the spray chamber with coolant from the distribution chamber; each through opening is arranged on an upper side of the distribution chamber and extends between the distribution chamber and the spray chamber; multiple full jet nozzles which are suppliable with coolant from the spray chamber, each jet nozzle is configured to supply and output a coolant jet of a coolant to the rolled material in an output direction, and is configured so that the coolant jet has a substantially constant jet diameter; each full jet nozzle comprises a tubular nozzle body which includes an open end arranged in an upper region of the cooling bar inside the spray chamber, the open end configured to receive coolant into the full jet nozzle, the tubular nozzle body extending fully inside the spray chamber from the bottom to an upper region above the upper side of the distribution chamber; wherein the open end is arranged above a height of the upper side of the distribution chamber, wherein the full jet nozzles are positioned in a plurality of nozzle rows extending transversely to the transport direction; and wherein the full jet nozzles of various nozzle rows of the plurality of nozzle rows are positioned to be offset to one another in the transport direction.

2. The cooling bar as claimed in claim 1, wherein a nozzle density of the multiple full jet nozzles of the cooling bar and the nozzle density vary transversely to the transport direction.

3. The cooling bar as claimed in claim 1, wherein an outlet diameter of the full jet nozzles varies transversely to the transport direction.

4. The cooling bar as claimed in claim 1, wherein a distance between the nozzles of the full jet nozzles adjacent one another in each of the nozzle rows varies.

5. The cooling bar as claimed in claim 1, further comprising: at least one coolant deflecting device configured for conducting coolant which is output by the full jet nozzles which are arranged at an edge region of the spray chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective representation of a first exemplary embodiment of a cooling bar according to the invention,

(2) FIG. 2 shows a sectional representation of the cooling bar shown in FIG. 1,

(3) FIG. 3 shows a bottom view of the cooling bar shown in FIG. 1,

(4) FIG. 4 shows a bottom view of a second exemplary embodiment of a cooling bar,

(5) FIG. 5 shows a bottom view of a third exemplary embodiment of a cooling bar,

(6) FIG. 6 shows a bottom view of a fourth exemplary embodiment of a cooling bar,

(7) FIG. 7 shows a bottom view of a fifth exemplary embodiment of a cooling bar,

(8) FIG. 8 shows a bottom view of a sixth exemplary embodiment of a cooling bar,

(9) FIG. 9 shows volume flows of a coolant output by cooling bars shown in FIGS. 1 to 8 in dependence on a position,

(10) FIG. 10 shows a sectional representation of a seventh exemplary embodiment of a cooling bar,

(11) FIG. 11 shows a sectional representation of an eighth exemplary embodiment of a cooling bar and

(12) FIG. 12 shows a rolling line for hot rolling rolled material with a cooling device for cooling the rolled material.

DESCRIPTION OF EMBODIMENTS

(13) Correlating parts are provided with the same reference symbols in all figures.

(14) FIGS. 1-3 show schematic representations of a first exemplary embodiment of a cooling bar 1 for cooling rolled material 5, which material is moved in a transport direction 3 (see FIG. 12).

(15) FIG. 1 shows a perspective representation of the cooling bar 1, FIG. 2 shows a sectional representation of the cooling bar 1 and FIG. 3 shows a bottom view of the cooling bar 1. In the figures, the transport direction 3 defines a Y direction of a Cartesian coordinate system with coordinates X, Y, Z, the Z axis of which extends vertically upward, i.e. runs in the opposite direction to the direction of the force of gravity. The cooling bar 1 extends transversely to the transport direction 3 in the X direction over the width of the rolled material 5.

(16) The cooling bar 1 includes a spray chamber 7, a distribution chamber 9, multiple full jet nozzles 11 and two optional coolant deflecting devices 12. The spray chamber 7 and the distribution chamber 9 are each realized as a cavity with a longitudinal axis which extends in the X direction transversely to the transport direction 3. In this case, the distribution chamber 9 has a substantially rectangular cross section in a plane perpendicular to its longitudinal axis. In a plane perpendicular to its longitudinal axis, the spray chamber 7 comprises a cross section which has the form substantially of the Greek capital letter Gamma, the horizontally extending portion of the Gamma extending above the distribution chamber 9.

(17) The spray chamber 7 and the distribution chamber 9 are connected together by multiple through openings 13. The through openings 13 are arranged on an upper side of the distribution chamber 9 one behind another in the X direction transversely to the transport direction 3. The distribution chamber 9 is fillable from the outside with a coolant, for example with cooling water, via a coolant inlet which is not shown. The spray chamber 7 is fillable with the coolant from the distribution chamber 9 via the through openings 13.

(18) By means of each full jet nozzle 11, a coolant jet of coolant with an almost constant jet diameter may be output from the spray chamber 7 to the rolled material 5 in an output direction 15 from one output side 17 of the cooling bar 1. The output direction 15, in this case, is the direction of the force of gravity, i.e. the opposite direction to the Z direction. The output side 17, in this case, is the bottom side of the cooling bar 1. Each full jet nozzle 11 comprises a tubular nozzle body 19 with a vertically extending longitudinal axis, i.e. parallel to the Z axis. The nozzle body 19 extends inside the spray chamber 7 from a bottom of the spray chamber 7 to an open end 21 of the nozzle body 19, which is arranged in an upper region of the spray chamber 7 above the height of the upper side of the distribution chamber 9 and through which coolant from the spray chamber 7 may be fed into the full jet nozzle 11. The nozzle bodies 19 are realized, for example, in a hollow cylindrical manner or they taper in each case conically from their open end 21 toward the bottom of the spray chamber 7. The full jet nozzles 11 each comprise an outlet opening 22, the outlet diameter D of which, for example, is between 3 mm and 20 mm, preferably up to 12 mm.

(19) The advantageous effect of the realization of the cooling bar 1 is that in the event of an interruption in the cooling of the rolled material 5, after interruption in the coolant supply to the distribution chamber 9, coolant may still only run only out of the region of the spray chamber 7 located above the open ends 21 of the nozzle bodies and out of the nozzle bodies 19 themselves to the rolled material 5 while the remaining volume of the spray chamber 7 and the distribution chamber 9 remain filled with coolant.

(20) The cooling bar 1 additionally comprises a nozzle density of the full jet nozzles 11 which varies transversely to the transport direction 3. The nozzle density in this embodiment is at its maximum in a central region of the cooling bar 1 and decreases transversely to the transport direction 3 toward the edge regions of the cooling bar 1 (see FIG. 3). In this case, the full jet nozzles 11 are arranged in three nozzle rows 23-25 which extend transversely to the transport direction 3. The full jet nozzles 11 of different nozzle rows 23-25 are arranged offset to one another in the transport direction 3. The variation in the nozzle density transversely to the transport direction 3 is achieved by providing a distance d between nozzles of full jet nozzles 11 adjacent one another of each nozzle row 23-25. The distance d between nozzles is at a minimum in the central region of the cooling bar 1 and increases transversely to the transport direction 3, toward the edge regions of the cooling bar 1. For example, the distance d between nozzles increases parabolically from the central region to each edge region of the cooling bar 1. As a result, temperature differences in the rolled material 5 may be advantageously reduced when the temperature of the rolled material 5 decreases from a central region of the rolled material 5 to the edge regions of the rolled material 5. The distance d between nozzles varies, for example, between 25 mm and 70 mm.

(21) Each optional coolant deflecting device 12 is arranged under an edge region of the spray chamber 7 and is provided for the purpose of collecting and conducting coolant which is output by full jet nozzles 11 arranged in the respective edge region of the spray chamber 7 (so-called edge masking). This prevents the coolant does not passing onto the corresponding edge region of the rolled material 5 and cooling the edge region of the rolled material 5 too strongly. For this purpose, each coolant deflecting device 12 comprises a coolant collecting container 12.1 and a coolant draining pipe 12.2. The coolant draining pipe 12.2 is arranged on a bottom side of the coolant collecting container 12.1 and conducts coolant collected in the coolant collecting container 12.1.

(22) Each of FIGS. 4-7 shows a bottom view of the respective cooling bar 1 in a further exemplary embodiment of a cooling bar 1. The cooling bar 1 of each of the exemplary embodiments differs from the cooling bar 1 shown in FIGS. 1-3 simply by the distribution of the full jet nozzles 11 transversely to the transport direction 3. As in the cooling bar 1 shown in FIGS. 1-3, the full jet nozzles 11 are arranged in three nozzle rows 23-25 which extend transversely to the transport direction, the full jet nozzles 11 of different nozzle rows 23-25 are arranged offset to one another in the transport direction 3.

(23) FIG. 4 shows a cooling bar 1 in which the distance d between nozzles of full jet nozzles 11 adjacent one another in each nozzle row 23-25 decreases from the central region of the cooling bar 1 transversely to the transport direction 3 toward the edge regions of the cooling bar 1 (for example parabolically). The nozzle density of the full jet nozzles 11 increases from the central region of the cooling bar 1 toward the edge regions of the cooling bar 1. As a result, temperature differences in the rolled material 5 may be advantageously reduced when the temperature of the rolled material 5 increases from a central region of the rolled material 5 to the edge regions of the rolled material 5.

(24) FIG. 5 shows a cooling bar 1 in which the distance d between nozzles of full jet nozzles 11 adjacent one another of all nozzle rows 23-25 is the same but the nozzle rows 23-25 extend to the left by different amounts from an edge region of the cooling bar 1 located on the right in FIG. 5 so that the nozzle density comprises a maximum nozzle density in the edge region located on the right. As a result, temperature differences in the rolled material 5 may be advantageously reduced when the temperature of the rolled material 5 decreases from the edge region of the rolled material 5 located on the right to the edge region of the rolled material 5 located on the left.

(25) FIG. 6 shows a cooling bar 1 in which the distance d between nozzles of full jet nozzles 11 adjacent one another of all nozzle rows 23-25 is also the same but the nozzle rows 23-25 extend to the right by different amounts from an edge region of the cooling bar 1 located on the left in FIG. 6 so that the nozzle density comprises a maximum nozzle density in the edge region located on the left. As a result, temperature differences in the rolled material 5 may be advantageously reduced when the temperature of the rolled material 5 decreases from the edge region of the rolled material 5 located on the left to the edge region of the rolled material 5 located on the right.

(26) FIG. 7 shows a cooling bar 1 in which the distance d between nozzles of full jet nozzles 11 adjacent one another of all nozzle rows 23-25 is the same and also the nozzle density transversely to the transport direction 3 is constant. Such a cooling bar 1 consequently brings about uniform cooling of the rolled material 5 transversely to the transport direction 3.

(27) FIG. 8 shows a cooling bar 1 which differs from the cooling bar shown in FIG. 7 only as a result of the outlet diameter D of the full jet nozzles 11 varying transversely to the transport direction 3. In this case, the outlet diameter D is maximum in the central region of the cooling bar 1 and decreases toward the edge regions of the cooling bar 1 transversely to the transport direction 3. The decrease is able to be parabolic, for example.

(28) The exemplary embodiments of cooling bars 1 shown in FIGS. 1-8 may be modified in various ways. For example, the distribution chamber 9 may be omitted in each case, so that the spray chamber 7 is filled directly with coolant instead of being filled via the distribution chamber 9. As an alternative, the full jet nozzles 11 may extend by a smaller distance or not at all into the spray chamber 7, i.e. the nozzle bodies 19 may be realized in a shorter manner or be completely omitted. In addition, the full jet nozzles 11 may be arranged in a number of nozzles rows 23-25 which deviates from three.

(29) The exemplary embodiment shown in FIG. 8 may be modified additionally so that the outlet diameter D of the full jet nozzles 11 varies transversely to the transport direction 3 in a manner other than in the case of the cooling bar 1 shown in FIG. 8. For example, the outlet diameter D may be at a minimum in the central region of the cooling bar 1 and may increase transversely to the transport direction 3 toward the edge regions of the cooling bar 1, or the outlet diameter D may be at a maximum in an edge region of the cooling bar 1 and may decrease transversely to the transport direction 3 toward the edge region located opposite said edge region.

(30) FIG. 9 shows a schematic representation of volume flows V.sub.1-V.sub.5 of a coolant output by cooling bars shown in FIGS. 1-8 in dependence on a position transversely to the transport direction 3.

(31) A first volume flow V.sub.1 is generated by the cooling bar 1 shown in FIGS. 3-8 and decreases from a central region of the cooling bar 1 toward the edge regions, the decrease running, for example, parabolically.

(32) A second volume flow V.sub.2 is generated by the cooling bar 1 shown in FIG. 4 and increases from a central region of the cooling bar 1 toward the edge regions, the increase running, for example, parabolically.

(33) A third volume flow V.sub.3 is generated by the cooling bar 1 shown in FIG. 5 and decreases from a first edge region toward the second edge region of the cooling bar 1.

(34) A fourth volume flow V.sub.4 is generated by the cooling bar 1 shown in FIG. 6 and decreases from the second edge region toward the first edge region of the cooling bar 1.

(35) A fifth volume flow V.sub.5 is generated by the cooling bar 1 shown in FIG. 7 and is constant transversely to the transport direction 3.

(36) FIG. 10 shows a sectional representation of a further exemplary embodiment of a cooling bar 1. The distribution chamber 9 is arranged below the spray chamber 7. Once again, the spray chamber 7 and the distribution chamber 9 are connected together by multiple through openings 13 and the cooling bar 1 comprises multiple full jet nozzles 11, each of which comprise a tubular nozzle body 19 with a vertically extending cylinder axis, i.e. parallel to the Z axis. In this exemplary embodiment, each of the nozzle bodies 19 extends from a bottom of the distribution chamber 9 through the distribution chamber 9 into the spray chamber 7 Each nozzle body comprises an open end 21, through which coolant from the spray chamber 7 may be fed into the full jet nozzle 11. The full jet nozzles 11, once again a nozzle density which varies transversely to the transport direction 3 and may be arranged distributed in an analogous manner to any of the exemplary embodiments shown in FIGS. 1-6.

(37) FIG. 11 shows a sectional representation of a further exemplary embodiment of a cooling bar 1. The distribution chamber 9 is arranged below the spray chamber 7. Once again, the spray chamber 7 and the distribution chamber 9 are connected together by multiple through openings 13, and the cooling bar 1 comprises multiple full jet nozzles 11. The full jet nozzles 11 are guided out of the spray chamber 7 at an upper side of the chamber 7 and are directed straight upward so that they output coolant upward. A cooling bar 1 shown in FIG. 11 is consequently provided for being arranged below the rolled material 5 and for distributing coolant on a bottom side of the rolled material 5. The full jet nozzles 11 may, once again, comprise a nozzle density which varies transversely to the transport device 3.

(38) FIG. 12 shows a schematic representation of a rolling line 27 for hot rolling rolled material 5 which is transported in a transport direction 3 through the rolling line 27. The rolling line 27 includes a finishing line 29 and a cooling section 31. Multiple roll stands 33 arranged one behind another in the finishing line 29 reshape the rolled material 5. Two roll stands 33 are shown as an example in FIG. 12. However, the finishing line 29 may also comprise a different number of roll stands 33. The cooling section 31 connects to the finishing line 29 and comprises a cooling device 35 for cooling the rolled material.

(39) The cooling device 35 includes multiple cooling bars 1, a temperature measuring device 37 and a control device 39. Each cooling bar 1 comprises multiple full jet nozzles 11, through each of which outputs a coolant jet of a coolant with an almost constant jet diameter to the rolled material 5. Some cooling bars 1 are arranged one behind another in the feed direction of the material 5 above the rolled material 5. The bars output coolant jets spray downward onto the upper side of the rolled material 5. Other cooling bars 1 are arranged one behind another in the feed direction of the material 5 below the rolled material 5. The lower output coolant jets spray upward onto a bottom side of the rolled material 5. FIG. 12 shows an example of five cooling bars 1 arranged above the rolled material 5 and five cooling bars 1 arranged below the rolled material 5. However, the cooling device 35 may also comprise other numbers of cooling bars 1 arranged above and/or below the rolled material 5.

(40) At least two of the cooling bars 1, and preferably, are in each case at least four of the cooling bars 1 are arranged above the rolled material 5 and at least four of the cooling bars 1 arranged below the rolled material 5, have nozzle densities and/or outlet diameters D of their full jet nozzles 11 which vary differently from one nozzle to another, transversely to the transport direction 3. The remaining cooling bars 1 have a constant nozzle density as the exemplary embodiment shown in FIG. 7.

(41) The cooling bars 1 with varying nozzle densities and/or varying outlet diameters D are preferably arranged with reference to the transport direction upstream of the cooling bars 1 with constant nozzle densities. The achievement here is that at the start of the cooling section 31, where the temperature of the rolled material 5 is still very high, local temperature differences transversely to the transport direction 3 may be reduced by cooling bars 1 with nozzle densities which vary transversely to the transport direction 3, while following cooling bars 1 with constant nozzle densities only reduce the overall temperature of the rolled material 5 tempered uniformly transversely to the transport direction 3.

(42) For example, each of the first four cooling bars 1 arranged above the rolled material 5 and the first four cooling bars 1 arranged below the rolled material 5 include a cooling bar 1 with a nozzle density which decreases from a central region of the cooling bar 1 to the edge regions of the cooling bar 1 analogously to FIG. 3. They also include a cooling bar 1 with a nozzle density which increases from a central region of the cooling bar 1 to the edge regions of the cooling bar 1 analogously to FIG. 4. They include a cooling bar 1 with a nozzle density which decreases from a first edge region (located on the right in FIG. 5) of the cooling bar 1 to the second edge region (located on the left in FIG. 5) of the cooling bar 1 analogously to FIG. 5. These include a cooling bar 1 with a nozzle density which increases from the first edge region of the cooling bar 1 to the second edge region of the cooling bar 1 analogously to FIG. 6.

(43) In addition, each of the cooling bars 1 arranged above the rolled material 5 preferably comprises full jet nozzles 11 and/or a spray chamber 7 and a distribution chamber 9 as the cooling bars 1 shown in FIGS. 1 and 2 in order to reduce coolant running from the coolant bars 1 onto the rolled material 5 in the event of an interruption in coolant supply to the cooling bars 1. The coolant bars 1 arranged below the rolled material 5 may be realized in a simpler manner, i.e. those cooling bars 1 may comprise simply realized full jet nozzles 11 without elongated nozzle bodies 19 and/or may not be divided into a spray chamber 7 and a distribution chamber 9, as no coolant may run onto the rolled material 5 from the cooling bars 1 arranged below the rolled material 5 in the event of an interruption in the coolant supply to the cooling bars 1.

(44) The temperature measuring device 37 is preferably arranged as shown in FIG. 12 upstream of the cooling bars 1 of the cooling device 35. In addition, a further temperature measuring device 37 may be arranged downstream of a cooling bar 1 of the cooling device 35. The temperature measuring device 37 is provided for the purpose of determining a temperature distribution of a temperature of the rolled material 5 transversely to the transport direction 3. For example, the temperature measuring device 37 may comprise an infrared scanner for recording the temperature with an accuracy of preferably ±2° C.

(45) The control device 39 is provided for the purpose of controlling flow volumes of coolant to the individual cooling bars 1 in dependence on the temperature distribution of the temperature of the rolled material 5 transversely to the transport direction 3 determined with the temperature measuring device 37. The control device 39 includes a control unit 47, two coolant pumps 49 and a control valve 51 for each cooling bar 1.

(46) The flow volume of coolant to one of the cooling bars 1 is adjustable by each control valve 51. The control valves 51 of the cooling bars 1 arranged above the rolled material 5 are connected to one of the two coolant pumps 49. The control valves 51 of the cooling bars 1 arranged below the rolled material 5 are connected to the other coolant pump 49. Instead of two coolant pumps 49, it is also possible to provide a different number of coolant pumps 49, for example only one coolant pump 49, which is connected to all control valves 51, or to provide more than two coolant pumps 49, which are each connected to only one control valve 51 or to a subset of control valves 51. Instead of the coolant pumps 49, it is alternatively or additionally possible to provide an overhead tank filled with coolant which is arranged at a suitable height above the control valves 51 and from which the control valves 51 are supplied with coolant. In cases in which a supply pressure of a coolant supply system, for example a water supply system, is already sufficient, it is even possible to dispense entirely with coolant pumps 49 or an overhead container. As each cooling bar 1 comprises full jet nozzles 11, it may be sufficient to supply the cooling bars 1 at a coolant pressure of approximately 4 bar. A typical flow volume of coolant of a cooling bar 1 is approximately 175 m.sup.3/h.

(47) Measured signals detected by the temperature measuring device 37 are supplied to the control unit 47. The coolant pumps 49 and control valves 51 are controllable by the control unit 47. Flow volumes of coolant to the individual cooling bars 1, in particular to those with varying nozzles densities, are calculated by the control unit 47 in dependence on the temperature distribution detected with the temperature measuring device 37 and are adjusted by controlling the control valves 51 in order to level out temperature differences in the temperature of the rolled material 5 transversely to the transport direction 3 by the use of and by a suitable combination of cooling bars 1 with varying nozzle densities and to reduce the temperature of the rolled material overall to a desired value, for example a coiling temperature. The flow volumes of coolant to the individual cooling bars 1, in this case, are calculated by the control unit 47, for example by a model produced from parameters of the rolled material 5 such as the thickness, temperature and/or thermal capacity thereof.

(48) Although the detail of the invention has been illustrated and described in more depth by preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by the expert without departing from the scope of protection of the invention.

LIST OF REFERENCES

(49) 1 Cooling bar 3 Transport direction 5 Rolled material 7 Spray chamber 9 Distribution chamber 11 Full jet nozzle 12 Coolant deflecting device 12.1 Coolant collecting container 12.2 Coolant draining pipe 13 Through opening 15 Output direction 17 Output side 19 Nozzle body 21 Open end 22 Outlet opening 23 to 25 Nozzle row 27 Rolling line 29 Finishing line 31 Cooling section 33 Roll stand 35 Cooling device 37 Temperature measuring device 39 Control device 47 Control unit 49 Coolant pump 51 Control valve d Distance between nozzles D Outlet diameter X, Y, Z Cartesian coordinates V.sub.1 to V.sub.5 Volume flow