阅读说明：本技术 用于无缝钢管的冷却装置 (Cooling device for seamless steel pipe ) 是由 T·米勒 P·蒂文 W·沃格尔 S·恩斯特 于 2020-04-14 设计创作，主要内容包括：本发明涉及一种冷却装置(1),所述冷却装置用于冷却由金属、优选钢制成的无缝的轧制管材(R),所述冷却装置具有带有一个或多个喷嘴(14)的喷嘴组件(10),所述喷嘴组件向所述管材(R)的外圆周面施加优选是水或者水混合物的冷却介质(K),而所述管材(R)沿着输送方向(F)被运送经过所述冷却装置(1)的冷却段,其中,所述喷嘴组件(10)具有入口(Z),经由所述入口能将所述管材(R)沿所述管材(R)的径向方向、优选向上从所述冷却段中取出。(The invention relates to a cooling device (1) for cooling a seamless rolled tube (R) made of metal, preferably steel, having a nozzle arrangement (10) with one or more nozzles (14) which apply a cooling medium (K), preferably water or a water mixture, to the outer circumferential surface of the tube (R), while the tube (R) is conveyed in a conveying direction (F) through a cooling section of the cooling device (1), wherein the nozzle arrangement (10) has an inlet (Z) via which the tube (R) can be removed from the cooling section in the radial direction of the tube (R), preferably upwards.)

1. A cooling device (1) for cooling seamless rolled tubes (R) made of metal, preferably steel, having a nozzle assembly (10) with one or more nozzles (14) which apply a cooling medium (K), preferably water or a water mixture, to the outer circumferential surface of the tube (R), while the tube (R) is conveyed in a conveying direction (F) through a cooling section of the cooling device (1), wherein the nozzle assembly (10) has an inlet (Z) via which the tube (R) can be taken out of the cooling section in the radial direction of the tube (R), preferably upwards.

2. A cooling device (1) as in claim 1, characterized by a nozzle assembly (10) having one or more nozzle arms (11) each having at least one distribution pipe (12) and one or more spray guns (13) connected thereto and extending therefrom, each spray gun having one or more nozzles (14).

3. A cooling device (1) according to claim 2, characterized in that it further has a fluid system which supplies cooling medium (K) to the distribution pipes (12), wherein preferably a plurality of distribution pipes (12) are each combined into a fluid unit (20) which is operated by a common pump (21) and/or switched by a common valve system.

4. A cooling device (1) according to claim 2 or 3, characterized in that the distribution pipe (12) conveys the cooling medium (K) in the cross-section of the pipe (R) and/or in the conveying direction (F).

5. A cooling device (1) according to any of the preceding claims, wherein the cooling section is shorter, preferably 8 to 16 meters long, than the pipe (R).

6. Cooling device (1) according to any one of the preceding claims, characterized in that the position and/or orientation and/or the volume flow of one or more nozzles (14) of the nozzle assembly (10) can be adjusted.

7. A cooling device (1) as in any one of the above claims, characterized by nozzles (14) of the nozzle assembly (10) forming a plurality of spray planes (S), which preferably can be adjusted in the conveying direction (F).

8. A cooling device (1) according to any of the preceding claims, wherein the cooling device cools the pipe (R) to a final temperature below the Ar3 transformation point, preferably to about 450 to 600 ℃.

9. Cooling device (1) according to one of the preceding claims, characterized in that the cooling device locally or approximately continuously adjusts the pressure value and/or the flow value of the cooling medium (K), preferably on the basis of the product and/or on the basis of measured values, empirical values and/or process models.

10. A cooling device (1) according to any one of the preceding claims, characterized in that the cooling section is divided into sections, wherein nozzle assemblies (10) for high-pressure injection, preferably with a pressure of more than 10bar, are provided in a first section and nozzle assemblies for lower pressures are provided in sections following in the conveying direction (F).

11. A cooling device (1) as in any one of the above claims, characterized by a cooling device (1) for discontinuous operation, so that one or more nozzles (14) can be switched on as the pipe (R) is fed into the cooling section and switched off as the pipe (R) is fed out of the cooling section, respectively, wherein preferably one or more sensors for identifying the pipe end are arranged inside or downstream of the cooling section.

12. A cooling arrangement (1) according to any of the preceding claims, characterized in that the cooling arrangement further has a housing completely or partly enclosing the nozzle assembly (10) and/or one or more compressed air eliminators.

13. A cooling device (1) as in any one of the above claims, characterized by the tube (R) being inclined with respect to the horizontal along the conveying direction (F) of the cooling section.

14. A cooling device (1) according to any of the preceding claims, characterized in that it is arranged directly downstream of a rolling mill for rolling the tube (R), whereby the tube (R) enters into the cooling section, while it is also connected in the rolling mill at the rear end.

15. Plant having a rolling mill, preferably a tension reducing mill or a sizing mill, and a cooling device according to any one of the preceding claims, which is located downstream of the rolling mill in a conveying direction (F) and serves for cooling a tube (R) rolled via the rolling mill.

16. The apparatus as claimed in claim 15, characterized in that the rolling mill has one or more cooling elements which reduce the temperature of the tube (R) in the rolling mill to below the Ar3 transformation point, preferably to below about 30 ° of the Ar3 transformation point.

Technical Field

The invention relates to a cooling device for cooling seamless rolled pipes, preferably steel pipes, having a nozzle assembly for applying a cooling medium to the outer circumferential surface of the pipe.

Background

In the production of seamless steel pipes, a tension reducing mill or a sizing mill is used, which has a plurality of mill stands arranged one behind the other in the direction of transport of the pipe. The parent tube from the prefabrication train is placed in a sizing or stretch reducing mill in the hot rolled state. The working temperature of the steel tube is mostly in the range between 900 ℃ and 1000 ℃. If the tube after the prefabrication plant has a temperature which is too low for rolling, it needs to be reheated in an intermediate furnace.

After exiting the mill, the material temperature is still above the austenitizing point (i.e., the Ar3 transformation point), depending on the material quality, approximately 820 ℃ to 840 ℃. The pipe is usually cooled in air by natural convection. As a result, normally rolled structures are produced, i.e. the tubes are moderately grain-refined, mostly substantially free of deformation textures which have a negative effect on the mechanical properties.

For high quality pipes, such as pipes for transporting oil and gas or pipes for construction, improved mechanical properties are required, in particular higher strength in combination with high toughness and high weldability. In order to improve the mechanical properties, it is known to temper rolled and cooled tubes in special heat treatment lines. In this case, the tube is reheated to the austenitizing temperature in a first temperature control step, then rapidly cooled in a quenching device, whereby a high-strength transformation phase, such as martensite, is formed, and finally reheated to eliminate internal stresses.

This additional heat treatment is technically complex and energy intensive. For this reason, methods have been developed which use the residual heat of the rolling process together for the heat treatment. For this purpose, the tube is cooled very rapidly after passing through a sizing or stretch-reducing mill, wherein a significantly increased cooling rate compared to a normal cooling bed must be achieved. The required cooling rate is passed through special cooling stages which are not standard equipment for seamless tube rolling mills. The cooling section directly accelerates the cooling of the tube after it leaves the rolling mill by applying a cooling medium, such as, for example, water or a water/air mixture, from the outside.

Document EP2682485B1 thus describes a method and a plant for producing seamless steel tubes with a continuous cooling section downstream of the last rolling stand, said plant having a plurality of distribution rings arranged concentrically around the rolling stock. The distribution ring has three or more nozzles for spraying a cooling medium onto the pipe to be cooled.

According to this prior art, the distributor ring surrounds the pipe to be cooled concentrically with respect to its central axis. A plurality of such distributor rings must be provided in order to cool the tubes sufficiently quickly while they are being transported out of the rolling mill. The disadvantage is that in the event of a fault, in the case of a tube still on the outlet side of the rolling mill, it is not easy to remove the tube from the transport section, since the tube is surrounded by the distribution ring. Instead, the tube must be cut into small pieces, followed by manual removal from the cooling section.

According to another solution known from document WO2016/035103a1, the tube to be cooled is lifted from below into the cooling device. In this case, the tube must be rotated about its own axis during cooling in order to achieve uniform cooling. However, in the case of a continuous cooling section directly downstream of the rolling mill, it is not possible to put the tube into rotation, since the rear end of the tube is still connected in the rolling mill at the beginning of the outfeed process, i.e. at the beginning of the cooling. Furthermore, the length of the tube downstream of the rolling mill is in most cases significantly greater than in heat treatment lines, since in the latter the tube has been cut to a finished length of 8 to 14 metres, while the tube in the outlet of the rolling mill is on the contrary not cut, up to 100 metres. Such long cooling sections are technically complicated and difficult to operate economically.

Disclosure of Invention

The aim of the invention is to improve the continuous cooling process of seamless rolled tubes made of metal, preferably steel, and in particular to improve the operational safety thereof.

This object is achieved with a cooling device having the features of claim 1 and with an apparatus having the features of claim 15. Advantageous developments emerge from the dependent claims, the following figures of the invention and the description of preferred embodiments.

The cooling device according to the invention is used for cooling seamless rolled pipes. The pipe is a metal pipe, preferably a steel pipe. The pipe comprises a variety of alloys, however, the mechanical properties of which, such as strength, tensile strength, toughness, weldability and the like, can be improved by heat treatment. The pipe is especially made of a high quality alloy, which is suitable for applications in oil and gas transport or for construction pipes.

The cooling device has a nozzle arrangement with one or more nozzles, which apply a cooling medium, preferably water or a water mixture, to the outer circumferential surface of the tube, while the tube is conveyed in the conveying direction through the cooling section of the cooling device. The term "water mixture" refers to a water-based cooling medium with one or more additives. The additive may comprise a dissolved solid, liquid or gas. The cooling medium is then, for example, a water/air mixture. By "cooling section" is meant here that section of the cooling device in the conveying direction in which the cooling medium is applied to the pipe. The cooling device provides a continuous cooling process, since the pipe is cooled by the cooling section during transport or transport.

According to the invention, the nozzle assembly has an inlet via which the tube can be removed from the cooling zone in the radial direction thereof, i.e. perpendicular to the longitudinal extent of the tube. In other words, the nozzle assembly does not completely surround the tube in the circumferential direction, but is open or can be opened on one side. The inlet is dimensioned such that the pipe can be removed laterally or radially from the cooling section. The inlet is preferably designed such that the tube can be removed upwards (as seen in the direction of gravity). Furthermore, the inlet preferably extends straight parallel to the tube axis in order to simplify the arbitrary removal of the tube from the cooling section. It is to be noted in this connection that a plurality of inlets may also be provided.

Thus, the nozzle assembly does not include a closed-loop structure. Instead, at least one inlet is provided which allows the tube to be removed from the cooling section in the radial direction in the event of a malfunction, such as an accident. The working space in the region of the inlet is not obstructed by pipes, tubes or the like. A cooling section is thus formed which, on the one hand, can be sufficiently short to be able to handle pipelines which have not yet been disconnected, for example up to 100 meters, and, on the other hand, can remove the pipe R from the cooling section from one side without having to cut it into smaller pipe sections in a cooling device beforehand. Furthermore, the inlet facilitates any maintenance and cleaning work at the cooling device.

The cooling device is particularly preferably used for rapidly cooling a pipe directly downstream of a rolling mill, such as a stretch reducing mill or a sizing mill. The term "directly downstream" means here that the tube enters the cooling section of the cooling device, while still being connected in the rolling mill at the downstream end. It is to be noted in this connection that the terms "upstream" and "downstream" are both relative to the transport direction of the tube.

Although the concentric distribution rings are omitted, in order to ensure uniform cooling along the tube circumference, the nozzles may be designed, arranged and aligned such that the amount of sprayed cooling medium is substantially constant along the tube circumference. In other words, the flow rate and the spray direction of the cooling medium K can be adjusted for each nozzle, so that a symmetrical and concentric cooling is achieved or at least approximately achieved.

Preferably, the spray nozzle assembly has for this purpose one or more spray nozzle arms, each having at least one distribution pipe and one or more spray guns connected thereto and extending therefrom, each with one or more spray nozzles. The provision of the nozzle arm ensures that the nozzle is supplied with the cooling medium in a structurally simple manner without the supply line having to completely surround the tube in the circumferential direction. The lances may be of different lengths in order to spray the cooling medium as uniformly as possible over the entire pipe circumference. In the case of straight distribution pipes, the spray guns at the edge portions can be configured longer than the spray guns in the middle of the respective distribution pipe, whereby the spray nozzles lie at least approximately on an imaginary distribution ring.

Preferably, the cooling device also has a fluid system which supplies the distribution lines with a cooling medium, wherein a plurality of distribution lines are each combined to form a fluid unit which is operated by a common pump and/or is switched by a common valve system. By means of such a modular combination of the fluid supply devices, the fluid supply can be simplified in terms of construction and at the same time the nozzles can be operated locally with different pressures, volume flows, etc., whereby the cooling of the pipe can be optimized.

Preferably, the distribution pipe conveys the cooling medium in a cross section of the tube and/or in a conveying direction, whereby an inlet can be formed in a structurally simple manner, which inlet extends straight parallel to the tube axis.

Preferably, the cooling section is shorter than the pipe, for example about 8 to 16 meters long. In this way, a compact cooling device is formed, whereby the tempering of the tube can be achieved by means of a heat treatment with a structurally reasonable expenditure.

Preferably, the position and/or orientation and/or the volume flow of one or more nozzles of the nozzle assembly can be adjusted, whereby the cooling effect can be flexibly adjusted, for example, depending on product parameters and/or process parameters.

Preferably, the nozzles of the nozzle assembly form a plurality of spray planes, which can be adjusted or moved substantially along the conveying direction. Each spray plane may then have, for example, two spray nozzle arms with a plurality of spray guns in each case. By suitably positioning the spray planes, the cooling effect can be flexibly adjusted, for example, depending on product parameters and/or process parameters.

Preferably, the cooling device cools the pipe to a final temperature below the Ar3 transformation point, thereby forming a high strength transformation phase such as martensite. For this purpose, the pipe is preferably cooled to about 450 ℃ to 600 ℃. The output temperature, i.e. the temperature at which the tube leaves the rolling mill, is, for example, 820 ℃ to 840 ℃.

Preferably, the cooling device adjusts the pressure value and/or the flow value of the cooling medium locally or approximately continuously, preferably in dependence on the product and/or on the basis of measured values, empirical values and/or process models. The adjustability is associated with a section along the cooling section, whereby the thermal conductivity in the transport direction can be flexibly adjusted. The adjustable segments may each include one or more jet planes, nozzle arms, and the like; however, it can also be refined to the structural level of a single nozzle. This is what is meant by the term "approximately continuous".

Preferably, the cooling sections are divided such that in a first section a nozzle assembly for high-pressure injection, preferably with a pressure of more than 10bar, is provided and in a section following in the conveying direction a nozzle assembly for a lower pressure is provided. Thus, for example, more than 10000W/(m) can be achieved in the high-voltage range²K) Thereby enabling sudden cooling of the pipe.

Preferably, the cooling device is used for discontinuous operation, so that one or more nozzles can be switched on as the pipe is fed into the cooling section, i.e. as the front pipe end passes, and can be switched off as the pipe is fed out of the cooling section, i.e. as the rear pipe end passes, wherein preferably one or more sensors for detecting the pipe end are arranged in or downstream of the cooling section. Thus, the entry of cooling medium into the pipe can be avoided.

Preferably, the cooling device further has a housing that completely or partially encloses the nozzle assembly, and/or one or more compressed air eliminators (drucklufstreifer). The cooling medium is prevented from polluting the environment by the housing, and in particular, the spray water load and the water vapor load of the environment can be reduced. Compressed air eliminators can be used for similar purposes to prevent the entry of cooling medium into particularly dangerous installations, such as wall thickness measuring points for radiation measurement or the remaining measuring points upstream and/or downstream of the cooling section.

Preferably, the tube is inclined in relation to the horizontal in the transport direction of the cooling section, i.e. it is lowered or raised, so that the installation space can be shortened when transitioning from the rolling mill to any cooling bed.

The above-mentioned object is also achieved by a plant having a rolling mill, preferably a stretch reducing mill or a sizing mill, and a cooling device according to the above description. The cooling device is located downstream of the rolling mill in the conveying direction and is used for cooling a pipe rolled by the rolling mill.

The features, technical effects, advantages and embodiments described in relation to the cooling device apply analogously to the apparatus described above.

The cooling device is arranged in particular directly downstream of the rolling mill, whereby the residual heat of the rolling process is used together in a coordinated manner for tempering the tube by heat treatment.

Preferably, the rolling mill has one or more cooling elements that reduce the temperature of the pipe in the rolling mill to below the Ar3 transformation point, preferably to below about 30 ° of the Ar3 transformation point. In this way the cooling effect can be enhanced. The operating temperature or rolling temperature in the rolling mill has thus been reduced according to such an embodiment, so that a lower final rolling temperature than usual is used.

Other advantages and features of the present invention will appear from the following description of preferred embodiments. The features described therein can be implemented individually or in combination with one or more of the features described above, as long as these features are not mutually inconsistent. Preferred embodiments are described below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic cross-sectional view of a nozzle assembly with attached fluid units of a continuous cooling section according to one embodiment;

FIG. 2 is a top view of the nozzle assembly shown in FIG. 1;

FIG. 3 is a schematic cross-sectional view of a nozzle assembly according to another embodiment of a continuous cooling section;

fig. 4 shows a top view of the nozzle assembly with attached fluid unit according to fig. 3.

Detailed Description

Preferred embodiments are described next with reference to the drawings. Wherein the same, similar or identically functioning elements are provided with the same reference numerals in different drawings, and overlapping descriptions for these elements are partially omitted to avoid redundancy.

FIG. 1 is a schematic cross-sectional view of a nozzle assembly 10 with attached fluid units 20 according to one embodiment of a continuous cooling section. Fig. 2 shows a top view of the nozzle assembly 10.

The nozzle assembly 10 is part of a cooling device 1 which is preferably arranged as a continuous cooling section directly downstream of a rolling mill for rolling seamless tubes R. The term "directly" here means: the tube R enters the continuous cooling section while still being connected in the rolling mill at its downstream end, seen in the conveying direction F (see fig. 2) of the tube R.

The pipes R are made of metal, preferably steel, and comprise, inter alia, high-quality alloys suitable for use in oil and gas transport or for construction pipes.

The above-mentioned rolling mill, which is preferably a stretch reducing mill or a sizing mill, is not shown in the figures, and has a plurality of roll stands arranged one behind the other in the conveying direction F of the tube R. The mother pipe from the prefabricating apparatus is fed into a rolling mill in a hot rolled state. The feed temperature is, for example, in the range from 900 ℃ to 1000 ℃. The tube R preferably has a temperature in excess of 820 ℃ to 840 ℃ when exiting the rolling mill.

The nozzle assembly 10 has one or more nozzle arms 11 each having at least one distribution tube 12 and one or more spray guns 13 connected thereto and extending therefrom, each with one or more nozzles 14. The distribution pipe 12 is supplied via a fluid system with a cooling medium K, preferably water or a water mixture, which then flows via a lance 13 to a nozzle 14 and is released or sprayed from there onto the pipe R.

The nozzle arm 11 can be arranged with its distribution pipe 12 and spray guns 13 in a plane, which is referred to as the "spray plane" S. In the present exemplary embodiment, each spray plane S has, for example, two nozzle arms 11, each with a distributor pipe 12 and five spray guns 13 connected thereto. But is not limited in this regard.

More precisely, the number and arrangement of the nozzle arms 11, lances 13 and nozzles 14 can be freely chosen, as long as uniform cooling of the pipe R is ensured, and as described further below, the nozzle assembly 10 does not comprise a closed-loop structure.

Only two injection planes S are shown in the section of fig. 2. Of course, under normal conditions, the number of ejection planes S arranged along the transport path of the tube S is greater in order to exert a sufficient cooling effect. The cooling section, i.e. the section of the conveying path in which the cooling medium K is applied to the pipe R, can extend relatively short, for example 8 to 16 meters in total, in accordance with the number, position and orientation of the nozzles 14, the flow rate of the cooling medium K, etc.

The nozzle assembly 10 may be designed such that the ejection plane S or a part thereof is adjustable in the conveying direction F. For this purpose, the nozzle arm 11 or a part thereof can be movably supported. Alternatively or additionally, the lance 13 or a part thereof can be pivotably arranged, for example in such a way that the respective nozzle arm 11 is rotatably supported about its own axis. Furthermore, the nozzle assembly 10 does not necessarily require the construction of multiple well-defined spray planes. The lance 13 with its nozzle 14 can then be positioned and/or oriented, for example, in such a way that the cooling medium K is applied substantially uniformly to the pipe R, as viewed in the conveying direction F.

A plurality of dispensing tubes 12 may be combined into one fluid unit 20 each, which is operated by a common pump 21 and/or switched by a common valve system.

According to the embodiment shown in fig. 1 and 2, the distribution pipe 12 conveys a cooling medium K in the cross section of the tube R. Alternatively, the cooling medium K can also be conveyed along the longitudinal axis of the tube (corresponding to the conveying direction F), as in the exemplary embodiment shown in fig. 3 and 4. Of course, the distribution pipe 12 can also be arranged in other ways, as long as the inlet Z as explained below is ensured.

It is known to note that the nozzle assembly 10 does not include a closed-loop structure. More precisely, the nozzle arm 11 is open at least on one side, in order to be able to remove the pipe R from the cooling section in the radial direction, preferably upwards, in the event of a malfunction (accident). In other words, the nozzle assembly 10 leaves an unobstructed gap or inlet Z along the conveying direction F, through which the tube R can be removed, if necessary. The working space in the region of the inlet Z is not obstructed by pipes, tubes or the like. The dimension of the inlet Z is greater than the diameter of the pipe R to ensure unimpeded removal of the pipe R from the cooling section.

A cooling section is thus formed which is sufficiently short on the one hand to be able to handle pipelines which have not yet been disconnected, for example up to 100 meters, and on the other hand to be able to easily remove the pipe R from the cooling section, for example in the event of a malfunction, in particular without having to cut it off beforehand at the injection plane S.

Although the concentric distribution rings are omitted, in order to ensure uniform cooling along the tube circumference, the nozzles 14 may be designed, arranged and aligned such that the amount of sprayed cooling medium K is substantially constant along the tube circumference. In other words, the flow rate and the spray direction of the cooling medium K can be adjusted for each nozzle 14, so that a symmetrical and concentric cooling is achieved or at least approximately achieved. In the case of straight distribution pipes 12, as shown in fig. 1, the spray guns 13 at the edge portions can be configured longer for this purpose than in the middle of the respective distribution pipe 12, whereby the nozzles 14 lie at least approximately on an imaginary indexing ring.

The cooling device 1 set forth herein is suitable for cooling a pipe R to a final temperature of approximately 450 ℃ to 600 ℃, whereby a particularly fine grain structure can be achieved. Immediately after cooling by the cooling device 1, the pipe R can be further cooled to room temperature by air convection.

In conjunction with the preceding rolling section, the parent tube is preferably first cooled to a temperature below the Ar1 transformation point and then reheated to the rolling temperature. The tube R is then rolled in a rolling mill and transferred or conveyed to the cooling device 1 for subsequent rapid cooling.

According to an advantageous embodiment, the cooling section is divided into a plurality of sections, wherein nozzle assemblies 10 for high-pressure injection, for example with a pressure of more than 10bar, are provided in a first section and nozzle assemblies for lower pressures are provided in sections following along the conveying direction F. Thus, in the high-voltage region, more than 10000W/(m) can be realized²K) Thermal conductivity of (2).

Alternatively or additionally, a local or approximately continuous adjustment of the pressure value and/or the flow value of the cooling medium K, as seen in the conveying direction F, can be carried out as a function of the product and/or on the basis of measured values, empirical values and/or process models.

The cooling device 1 can be used for discontinuous operation, in that the nozzle arm 11 can be switched on, for example, as a function of the passage of the front tube end and switched off as the rear tube end passes, whereby the entry of the cooling medium K into the tube R can be avoided. For this purpose, one or more sensors for identifying the pipe ends can be arranged inside or downstream of the cooling section.

Preferably, the cooling section is located completely or partially in the housing in order to avoid contamination of the environment with the cooling medium K, in particular to reduce the spray water load and the water vapor load of the environment. For similar purposes, compressed air eliminators can be used to prevent the cooling medium K from entering particularly dangerous installations, such as wall thickness measuring points for radiation measurement or the remaining measuring points upstream and/or downstream of the cooling section.

The tube R can be tilted (raised or lowered) in the transport direction F of the cooling section, whereby the installation space during the transition from the rolling mill to any cooling bed can be reduced. Additionally or alternatively, the cooling section may be integrated into a transition region to the cooling bed. Since the spray chamber is not closed due to the inlet Z, the pipe R can be removed from the cooling zone and transferred into the cooling bed.

The cooling device 1 set forth herein is furthermore suitable for combination with additional cooling elements in a rolling mill in order to enhance the cooling effect. According to one embodiment, the operating temperature or rolling temperature in the rolling mill is reduced, so that a lower final rolling temperature than usual is applied. It is then possible to achieve supercooling of the tube material R in the rolling mill to a temperature of approximately 30 ℃ below the Ar3 transformation point.

All individual features mentioned in the embodiments can be combined with one another and/or substituted for one another as far as they are suitable, without departing from the scope of the invention.

List of reference numerals

1 Cooling device

10 nozzle assembly

11 nozzle arm

12 distribution pipe

13 spray gun

14 nozzle

20 fluid unit

21 pump

R pipe

F direction of conveyance

K cooling medium

S plane of injection

Z inlet