EP0144029B1 - Cooling tube for a cooling section for rapidly cooling steel wire rod or rod stock - Google Patents

Abstract

A cooling pipe arrangement (1) includes a pipe portion (2) in which two gripping elements (3) are arranged, with a coil spring (6) gripped between the gripping elements (3). The coil spring is surrounded by an annular space (15) into which opens a duct (16) for the coolant. The fluid which is supplied by way of the duct is conducted through the gap (19) between the turns of the coil spring, on to the rolled material which is conveyed through the cooling pipe arrangement. The width of the gap (19) may be varied by means of a setting ring (22).

Description

The invention relates to a cooling tube according to the preamble of claim 1.

Cooling tubes of this type are used to cool the rolling stock in or behind a rolling mill. On the one hand, it is intended to ensure that the temperatures of the rolling stock within the rolling mill do not exceed certain limit values, so that there is no impermissible decarburization or carbide precipitation. On the other hand, in order to set a certain structure of the rolling stock, the final rolling temperature on the finishing pass must be set exactly. Finally, certain mechanical properties of the rolling stock are to be adjusted by targeted cooling after the last rolling stand.

From DE-C-2 726 473 a cooling tube is known from two spaced-apart guide sleeves, between which a plurality of rods are arranged convergingly from one guide sleeve to the other on a pitch circle around the longitudinal axis of the cooling tube at a distance from one another. Slot-like through openings for the cooling liquid are thus formed between the individual rods. A pipe section which is pushed over the two guide sleeves and sealed with respect to this by means of sealing elements forms an annular space around the rods, which is connected by channels to a connection for the coolant. The cooling liquid can be introduced tangentially, so that the cooling liquid rotates around the rolling stock and the turbulence of the cooling liquid improves the heat transfer.

As is known, in order to maintain freedom from cracks and the structural uniformity of the rolling stock, certain temperature differences within the rolling stock must not be exceeded. The coolant throughput must therefore be set depending on the diameter of the rolling stock, temperature or steel grade. Since it is not readily possible in known cooling tubes to adapt the coolant throughput and thus the intensity of the cooling to the required cooling capacity, a complex control system with control elements is usually provided in the feed lines to the individual cooling tubes.

The invention has for its object to provide a cooling tube that allows adjustment of the coolant throughput with a simple structural design and thus an adaptation to the cooling capacity prescribed for the cooling tube in question.

The object is solved by the features of claim 1. Advantageous embodiments of the invention can be found in the remaining claims.

The solution according to the invention is characterized by a particularly simple construction. Between two sleeve-shaped clamping elements, which preferably also form the guide of the rolling stock, a helical spring is clamped, the turns of which are normally kept at a distance from one another, so that a helical gap results as a passage opening for the cooling liquid. Although a tension spring can also be used with suitable clamping between the tensioning elements, a compression spring is preferably used. The cross section of the wire from which the coil spring is formed is preferably round. The inside diameter of the helical spring is sufficiently large to prevent contact with the rolling stock on the one hand and to create a sufficient space for the access of the cooling liquid around the rolling stock.

The two clamping elements are fastened in a tube section which at the same time delimits an annular space around the helical spring, into which a channel for the supply of the coolant opens. In addition to the clamping elements required for guiding the rolling stock anyway, and in addition to seals and fastening means, the cooling tube thus only contains a coil spring and a pipe section provided with a water connection. The clamping elements can be designed identically. The cooling tube thus has a surprisingly simple structure. Nevertheless, with these elements, simply by changing the clamping length between the clamping elements, the coil spring can be compressed or pulled apart to a greater or lesser extent and the resulting change in the gap width between the turns of the coolant throughput can be adapted to the desired cooling capacity.

This principle not only allows simple adjustment of the coolant throughput when assembling the cooling tube, but also opens up the possibility with simple constructional means of being able to individually change the coolant throughput in a cooling tube built into the cooling section and to be able to adapt it to the desired cooling capacity. For this purpose, it is only necessary to design the construction so that the clamping length between the clamping elements can be changed. A threaded connection is particularly suitable for this, be it directly between at least one of the tensioning elements and the pipe section, or via an adjusting ring.

The gap width between the turns of the coil spring need not be constant. For example, the gap width on the entry side of the rolling stock into the spring can be larger than on the exit side. This is possible, for example, in that the coil spring is wound with a different pitch. It is also possible to achieve such a characteristic in that the coil spring consists of at least one row arrangement two coil springs with different pitch and possibly different spring constant is replaced. In addition, it is possible to arrange a plurality of coil springs one behind the other within a pipe section, each of which is clamped between clamping elements and to which an annular space with a channel for the coolant is assigned. Units each consisting of a helical spring clamped between two clamping elements, which are arranged one behind the other in a pipe section, can each be connected by a rigid sleeve, which ensures smooth guidance of the coolant flow entrained with the rolling stock. With such arrangements, the cooling characteristic can be changed within wide limits. On this occasion it should also be mentioned that the coolant throughput through the helical gap between the turns of the coil spring is generally set so that it is less than the possible throughput through the channel opening into the annular space. This is to ensure that the annular space is completely filled with cooling liquid and the rolling stock is cooled evenly over its entire circumference. By eccentrically opening the channel into the annular space, it is possible to achieve a rotation of the cooling water around the rolling stock and thereby to increase the cooling effect. The adjustability of the coolant throughput also includes the case that the helical spring is compressed until adjacent windings are in contact with one another and thus the coolant throughput is completely interrupted.

• Figur 1 eine Längsschnittansicht eines Kühlrohres,
• Figur 2 den Schnitt 11-11 von Fig. 1,
• Figur 3 eine der Fig. 2 entsprechende Ansicht einer abgewandelten Ausführungsform eines Kühlrohres,
• Figur 4 die Längsschnittansicht eines zwei Einheiten enthaltenden Kühlrohres, und
• Figur 5 die Längsschnittansicht einer weiteren Ausführungsform eines Kühlrohres.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. Show it :

• FIG. 1 shows a longitudinal sectional view of a cooling tube,
• 2 shows the section 11-11 of Fig. 1,
• 3 shows a view corresponding to FIG. 2 of a modified embodiment of a cooling tube,
• Figure 4 is a longitudinal sectional view of a cooling tube containing two units, and
• Figure 5 shows the longitudinal sectional view of a further embodiment of a cooling tube.

The cooling tube 1 shown in Fig. 1 is part of a cooling section which comprises a plurality of such cooling tubes.

The cooling tube 1 contains two clamping elements 3 of identical design in a tube section 2, between the facing end faces 4 and 5 of which a helical spring 6 is clamped. The two clamping elements 3 are fixed in the pipe section 2 by means of screws 7. The left end face 4 of the tensioning elements 3 each has an annular recess 8 and the right end face has ring shoulders 9 and 10. The coil spring 6 is seated with its left end on the inner annular shoulder 10 of the left clamping element 3 and with its right end in the annular recess 8 of the right clamping element 3.

Each clamping element has two annular grooves 11. A sealing element 12 is provided in each of the annular grooves 11 adjacent to the helical spring 6.

The two clamping elements 3 are designed as guide sleeves for the rolling stock and have a funnel 13 on the input side for this purpose. The inside diameter of the coil spring 6 is sufficiently larger than the inside diameter 14 of the clamping elements 3, so that it is ensured that the rolling stock does not come into contact with the coil spring. On the other hand, a sufficiently large annular space 15 must remain between the helical spring 6 and the inner wall of the tubular section 2 in order to ensure a radial inflow of coolant into the interior of the helical spring which is substantially uniform over the circumference of the helical spring. The annular space 15 is connected via a channel 16 to a connection for the cooling liquid. In the present case, the channel is formed by a circular opening 17 in the pipe section 2 and a connecting pipe 18. 1 flows through the channel 16 from bottom to top (arrow 24) into the annular space 15 and from there through the helical gap 19 formed by the coil spring 6 into the interior of the coil spring 6.

In operation, the rolling stock passes through the cooling tube 1 from left to right (arrow 25). The inner diameter 14 of the sleeve-shaped clamping elements 3 is approximately 1.5 to 3 times as large as the diameter of the rolling stock. The distance between the rolling stock and the inside of the coil spring 6 corresponds approximately to the distance between the outside of the coil spring and the inside wall of the pipe section 2.

The production of the cooling tube shown in Fig. 1 is very simple. Sections of standardized commercially available pipes can be used as pipe sections. After drilling the opening 17, the connecting pipe 18 is welded on. Then one of the two clamping elements 3 already equipped with a seal 12 is inserted into the pipe section 2 and fixed with screws 7. Then the coil spring 6 is inserted and finally the other clamping element 3 and this is fixed with screws.

In the illustrated embodiment, the length of the helical spring 6 and the two clamping elements 3 is chosen so that the end face 4 of the left clamping element and the annular shoulder 9 of the right clamping element are flush with the pipe section 2. The flow cross section through the helical gap 19 is smaller than the flow cross section of the channel 16, so that it is ensured that the annular space 15 is always filled with coolant in the operating state. The sleeve-shaped tensioning elements 3 and the coil spring 6 are arranged coaxially within the tube section 2, so that the coil spring 6 is approximately the same distance from the inner wall of the tube cut 2 has. For fluidic reasons, however, it can be expedient to offset the central axes of the tensioning elements 3 and the helical spring 6 somewhat parallel with respect to the central axis of the pipe section 2 in order to obtain an annular space 15 with a different cross section over the circumference. In addition, it may be appropriate to the width of the helical gap 19 not constant, as shown, but z. B. form decreasing from left to right. For this purpose, the coil spring only needs to be wound with changing pitch. Finally, it is also possible for the helical spring 6 to be conically tapered from one end to the other end.

As can be seen from the cross-sectional view according to FIG. 2, in the exemplary embodiment shown, the channel 16 opens centrally into the annular space 15, ie. H. the central axis of the connecting pipe 18 intersects the central axis of the pipe section 2, which also represents the central axis of the clamping elements 3 and the coil spring 6.

Fig. 3 shows a modified embodiment, in which the channel 16 opens eccentrically into the annular space 15. For this purpose, the central axis of the connecting pipe 18a is offset in parallel in comparison to the embodiment of Fig. 2, i. H. it no longer intersects the center line of the pipe section 2a. In this way, a tangential flow is generated within the annular space 15, which results in a rotation of the cooling liquid around the rolling stock through the gap 19 between the turns of the helical spring. This cooling therefore takes place with greater turbulence than in the example according to FIG. 2.

FIG. 4 shows a cooling pipe in which two units, each consisting of a helical spring 6 clamped between two clamping elements 3, are arranged one behind the other in a pipe section 2b and the two units are connected by a rigid sleeve 20. Each of the coil springs is assigned an annular space 15 and a channel 16 for the supply of the coolant. The rigid sleeve 20 is clamped in the same way as the coil springs 6, namely between the inner shoulder 10 of one clamping element 3 and the annular recess 8 of the next clamping element 3. The rigid sleeve 20 creates a compensating distance, the length of which depends on the length of the rigid sleeve 20 can be determined.

Instead of the rigid sleeve 20, another element can be used which is permeable to the cooling liquid, and a channel opening into the annular space around this element can be provided, through which the cooling liquid supplied via the channel 16 is at least partially removed again.

Fig. 5 shows an embodiment of the invention, which makes it possible not only in the manufacture, but also in the use of the cooling tube in a simple manner to adjust the flow cross section of the cooling liquid through the helical gap 19 of the coil spring 6 and to adapt it to the required conditions. For this purpose, the clamping length 21 between two clamping elements 3 can be changed. 5 corresponds essentially to that of FIG. 1. To change the clamping length 21, the right clamping element 3 is mounted in a longitudinally displaceable manner and lies with its end face facing away from the coil spring 6, in this case with the outer annular shoulder 9, on an adjusting ring 22 on, which is connected by a thread 23 to the pipe section 2c. For this purpose, the adjusting ring 22 is provided with an external thread and screwed into an internal thread on the right side of the pipe section 2c. By turning the adjusting ring 22, the helical spring 6 can be compressed to a greater or lesser extent, thereby reducing the gap width 19 to a value of 0 within wide limits. The adjusting ring 22 is thus a simple means for adjusting and also for switching off the cooling liquid supplied to the rolling stock within the cooling tube.

The threaded connection could also be provided between the right clamping element 3 and the pipe section 2c. In this case, the right clamping element would have to be rotated to change the clamping length 21.

Not only a coolant and especially water are suitable as coolants; gaseous coolants could also be used.

Claims (11)

1. A cooling pipe arrangement for a cooling section for rapid cooling of rolled wire or bar material (rolled material), comprising a pipe portion (2) in which are disposed two sleeve-like gripping elements (3) between which an insert member having a gap (19) as a through-flow opening for the coolant is gripped, and an annular space (15) which is defined by the insert member and a portion of the inside wall surface of the pipe portion (2) and which communicates through a duct (16) with a connection for the coolant, characterised in that the insert member is in the form of a coil spring (6) and the gripping elements (3) are fixed in the pipe portion (2).

2. A cooling pipe arrangement as set forth in claim 1 characterised in that the gripping elements at the same time form the guide means for the rolled material.

3. A cooling pipe arrangement as set forth in claim 1 or claim 2 characterised in that the spring- gripping length (21) between the gripping elements (3) is variable.

4. A cooling pipe arrangement as set forth in claim 3 characterised in that at least one of the gripping elements (3) is connected to the pipe portion (2c) by way of a screwthread (23).

5. A cooling pipe arrangement as set forth in claim 3 or claim 4 characterised in that at least one of the gripping elements (3) is mounted longitudinally displaceably and bears with its end face (5) that is remote from the coil spring (6) against a setting ring (22) which is connected to the pipe portion (2c) by a screwthread (23).

6. A cooling pipe arrangement as set forth in one of claims 1 to 5 characterised in that the two gripping elements (3) are of identical configuration.

7. A cooling pipe arrangement as set forth in one of claims 1 to 6 characterised in that the duct (16) for the coolant is arranged transversely with respect to the longitudinal axis of the cooling pipe portion (2).

8. A cooling pipe arrangement as set forth in one of claims 1 to 7 characterised in that the duct (16) for the coolant opens eccentrically into the annular space (15).

9. A cooling pipe arrangement as set forth in one of claims 1 to 8 characterised in that at least two coil springs (6) are arranged in succession in a pipe portion (2b), gripped between respective gripping elements (3), and a duct (16) for the coolant opens into each annular space (15) around the coil springs (6).

10. A cooling pipe arrangement as set forth in claim 9 characterised in that at least two units each comprising a coil spring (6) gripped between two gripping elements (3) are arranged in succession in a pipe portion (2b) and the units are connected by a rigid sleeve (20).

11. A cooling pipe arrangenent as set forth in one of claims 1 to 10 characterised in that the coil spring (6) is formed with a varying width of gap between the turns.

Images