EP0312843A1 - Process for heat exchange and its use in the controlled cooling of rolled products - Google Patents

Abstract

A process for heat exchange between liquid media, on the one hand, and likewise liquid media or solid bodies, on the other hand, if this is effected by means of flow or the solid body is subjected on all sides to a guided flow of liquid medium. A predetermined proportion of a gaseous medium is continuously admixed to the last-mentioned liquid medium, e.g. in the temperature-controlled cooling of rolling stock, in such a way that, during and after the deformation by rolling, the rolling stock is fed in in rolling-stock guide tubes (FR) through which water flows and to which the water is fed with a presettable inlet pressure from an annular nozzle 8, 9a of adjustable outlet cross-section which surrounds the rolling stock conveyed in in a feed tube, and the size of the outlet cross-section and/or of the inlet pressure is of adjustable magnitude, such that, taking effect as an injection nozzle, the annular nozzle 8, 8a produces mixtures of the water emerging from the outlet cross-section with the air drawn in from the feed tube in correspondingly different proportions. <IMAGE>

Description

The invention relates to a method for heat transfer between liquid media, on the one hand, and also liquid media or solid bodies, on the other hand, and to the use of the method for temperature-controlled cooling of rolling stock during and after the rolling deformation in rolling stock guide pipes through which water flows and which the water flows from with a presettable inlet pressure one which is fed to a ring nozzle with a variable outlet cross section and fitted in a feed pipe.

In the case of the method for heat transfer of the type mentioned in the first place, there is often the difficulty, especially when the heat transfer is to be carried out relatively slowly, to carry out the heat transfer with a predetermined heat transfer number which does not change via the transfer process, or else the heat transfer number is controlled Change the heat transfer number.

The invention has for its object to provide such a possibility with relatively little technical effort.

This object is achieved in that a container holding the liquid medium or a conduit for the flowing liquid medium or the solid body is acted upon on all sides by a flowing liquid medium to which a predetermined proportion of a gaseous medium is constantly mixed. As the invention further provides, water can advantageously be used as the liquid medium and air can advantageously be used as the admixing gaseous medium. There is also the possibility of making the pressure of the flowing medium changeable and definable or, insofar as the heat transfer is to take place on a solid body, to move it at a variable and definable speed.

A suitable device for carrying out these methods is a cylindrical outer tube which coaxially comprises an inner cylinder tube which receives the flowing medium. In this case, a nozzle head is expediently arranged at the open entrance of the outer cylinder tube, to which the liquid flowing medium can be fed, and which has an inlet pipe which can be axially displaced therein, with which together the nozzle head has an annular nozzle which surrounds the inner cylinder tube and for the outlet of the liquid medium with simultaneous suction form the gaseous medium through the open entrance of the outer cylinder tube.

The method can be used, for example, for temperature-controlled cooling of rolling stock in such a way that, for example, water is introduced into the nozzle head and emerges from the ring nozzle formed by the nozzle head and inlet pipe. The negative pressure which arises behind the outlet cross section of the nozzle formed in this way sucks air out of the well-known manner open entrance of the outer cylinder tube, so that a water-air mixture arises behind the nozzle, its composition can be changed within wide limits according to the invention by axial displacement of the inlet pipe. On its way through the outer cylinder tube, the water-air mixture acts on all sides of the inner cylinder tube, in which the liquid medium is guided, which is supposed to either absorb or release heat. Instead of this inner cylinder tube, a rod-shaped solid body, for example in wire form, can also be moved directly through the center of the outer cylinder tube at the desired speed, the periphery of this rod being acted upon directly by the water-air mixture.

The inlet pipe of the nozzle head and possibly the discharge pressure and rod speed can be controlled in a manner known per se with the aid of sensors and control devices, in accordance with values calculated on the basis of the sensor measurement results.

Working methods and devices are known (DE-B-16 02 356) in which, here the wire passing through at high speed of a wire rolling mill before it enters the wire reel and subsequent treatment devices working with air or other coolants in the same way Water is cooled so that the wire is completely enclosed by the water introduced into the wire guide tube through the ring nozzle and thereby releases its heat to the water. The primary purpose of the working methods and devices was to cool the wire down to a greater or lesser extent from the rolling heat and to prepare it for subsequent placement by means of a reel on horizontal conveyors, on which the wire was then further treated. It was tried to ver the cooling effect by increasing the inflow pressure of the water and / or by extending the wire guide tubes strengthen. Both measures found their limit in the pressure loss of the water over the pipe length caused by the pipe friction resistance between the pipe inner wall and water and also in the braking of the wire caused by the friction resistance of the wire peripheral surface compared to the water surrounding it. In addition to a number of improvements in the design of the wire guide tubes, particularly in their outlet area, which enables extensions of the wire guide tubes, it was also proposed to increase the cooling effect to arrange several such wire guide tubes one behind the other in the direction of wire movement.

However, all working methods and devices of this type have in common that, unlike cooling with air or gases, they do not allow specific extraction of certain amounts of heat for the purpose of controlling the cooling process from the outer circumference of the rolling stock to the center of the cross section; this primarily because there was no possibility of gaining influence over the amount of heat transferred from the rolling stock to the water over the respective length of a rolling stock guide pipe with the explained water exposure to the rolling stock surface, i.e. it was not possible to change the cooling process from the rolling stock circumference to the To control the cross-sectional center in a targeted manner. Attempts to influence such an influence by changing the inlet pressure or with a constant inlet pressure of the amount of water have been unsuccessful and have proved to be non-reproducible in practical operation with regard to the measured values of heat withdrawn. The arrangement of a plurality of rolling stock guide pipes with cooling water supply, which could be switched on or off, did not produce any useful results either. This is probably because the flow conditions in the respective rolling stock guide pipe can be influenced little, because of that, already explained training for changes in the operating conditions ie inlet pressure, outlet cross-section of the water from the ring nozzle, pipe length and outlet conditions from the rolling stock guide pipe left little space.

According to the invention, these known, known working methods and devices used for this purpose are to be improved so that the possibility is created for the rolling stock within the rolling stock guide tubes to be given predetermined or precalculated amounts of heat over a large setting range, with the aim, for example, of a permissible temperature difference between the core and to maintain the circumferential surface of the rolling stock or a defined surface temperature, for example the martensite point not to fall below.

This possibility is created in that the size of the outlet cross section of the ring nozzles and / or the circulating pressure of the water at the entrance of the rolling stock guide tubes are dimensioned such that the ring nozzle becomes effective as an injection nozzle, mixtures of the water emerging from the outlet cross section with from the supply tube bringing the rolling stock drawn-in air with correspondingly different proportions of both media in the mixture.

This application of the generic method, in which the cooling water, before it enters the rolling stock guide tube after exiting the exit cross section of the ring nozzle, air is mixed in more or less large quantities (aerator effect) allows the desired heat transfer coefficients to be achieved within wide limits change and set reproducible with the rest, essentially unchanged starting conditions such as water inlet pressure and water inlet temperature. The pressure and flow conditions within of the respective rolling stock guide tube remain balanced and stable over this large control range. With the help of these changes in the mixing ratio of water and air and possibly also the inlet pressure, temperature-controlled rolling results can be achieved with a corresponding design of the device elements, which correspond to those of the previous post-treatment of the rolling stock in air or similar cooling sections and which can sometimes exceed them. The setting range of the heat transfer numbers ranges from approx. 1000 to at least 35 000W- (m²K). In order to achieve this, the air fractions of the mixture can be between 0 and 90 vol.% According to the invention.

As the invention further provides, when the rolling stock is guided through a plurality of rolling stock guide tubes arranged one behind the other, each having ring nozzles with an adjustable outlet cross section, the cooling of the rolling stock in the individual successive guide tubes with definable different settings of the respective outlet cross section of the ring nozzles and / or of the inlet pressure of the water is effected.

To carry out the application of the generic method according to the invention, in order to maintain the operational equilibrium in the rolling stock guide pipes between the entrance and exit behind the exit of the rolling stock guide pipe, an elastically supported deflection cover which can be brought into and out of the cover position and which deflects the cooling water jet emerging from the exit downwards if arranged no rolling stock is moved through the rolling stock guide tube during breaks. In the case of larger diameters of the cooling tubes and the rolling stock, the deflection cover prevents the cooling water jet from acting on the rolling stock behind the outlet of the cooling tube, the cooling water jet the opposite wiper jet of the wiper nozzle head breaks through and may cause malfunctions. There is also the possibility according to the invention of providing the sensors which detect and report the swivel angle position of the deflection cover and the circumferential position of the rolling stock and a control device connected downstream thereof, which controls the swivel angle of the deflection cover in such a way that its outer edge maintains a definable distance above the rolling stock through it. This measure prevents the edge of the deflection cover from resting on the outer circumference of the rolling stock and thereby causing changes or damage to the rolling stock surface.

Finally, according to the invention, there is also the possibility of dividing the rolling stock guide tube into two partial tubes if the mathematically required length of a single tube would result in an excessive pressure drop in the tube. In this case, the respective output and input of these partial tubes would be coaxially opposite each other at the front, the input of the second partial tube in a known manner as an inlet funnel and the output of the first partial tube from a tube section which tapers conically in the flow direction and which is in a cylindrical shape Pipe section merges, are formed, the tapered pipe section and the cylindrical pipe section have longitudinal recesses open to the pipe center axis. The total cross section of these longitudinal recesses is dimensioned such that the through cross section of these two pipe sections is approximately equal to the through cross section of the first partial pipe.

The division of the rolling stock guide tube has the further advantage that, in the event of any malfunctions during the cooling operation, the sections of the rolling stock located in the guide tubes can be more easily removed from these shorter tubes.

The setting of the outlet cross section of the ring nozzles can be effected with a remotely controllable actuator for setting this outlet cross section.

In a device for performing the above-described method according to the invention, which consists of a stationary nozzle head connected to the water supply with a conical funnel attachment and a conically tapered beginning projecting and axially displaceable rolling stock inlet pipe, as is known from DE-U-71 34 676 be designed such that the inlet pipe is connected to the nozzle head by a screw thread and carries a worm wheel outside the nozzle head which can be driven by a worm shaft. There is also the possibility of designing the device in such a way that levers connected to an actuator are articulated at the end of the rolling stock inlet pipe located outside the funnel attachment of the nozzle head and are rotatably mounted about an axis running at a distance transversely to the center axis of the rolling stock inlet pipe. The levers can engage as a pair of levers with a sliding cam arranged at their free end in an annular groove arranged at the end of the rolling stock inlet pipe and with their other end can be fixedly connected to the axle mounted above or below the rolling stock inlet pipe, which at one free end has one on one Piston cylinder unit carries the actuated lever. There is still the possibility that To connect the inlet pipes of a Mehzhal nozzle head arranged in parallel next to one another via levers rotatably mounted about a common axis with the actuator.

Avoid the latter forms of training, the possible disadvantage when using worm gears that the screw thread and worm wheel become stuck due to self-locking, and the setting of several nozzle heads arranged in parallel next to one another can be synchronized by means of a single drive.

• Figur 1 die Gesamtvorrichtung von der Seite gesehen im Axialschnitt,
• Figur 2 u. 3 Einzelheiten aus Fig. 1 ebenfalls im Axial­schnitt in vergrößertem Maßstab,
• Figur 4 u. 5 eine weitere Einzelheit aus Fig. 1 im Axial- und im Radialschnitt im vergrößertem Maßstab,
• Figur 6 u. 7 Temperaturdiagramme von Abläufen der Arbeits­verfahren,
• Figur 8 eine andere Ausbildungsform der Vorrichtung im Axialschnitt und
• Figur 9 einen Schnitt nach der Linie A-A durch Fig. 8.

The invention is explained in more detail with reference to the embodiment shown in the drawing. Show in the drawing

• FIG. 1 the overall device seen from the side in axial section,
• Figure 2 u. 3 details from Fig. 1 also in axial section on an enlarged scale,
• Figure 4 u. 5 shows a further detail from FIG. 1 in axial and radial section on an enlarged scale,
• Figure 6 u. 7 temperature diagrams of work processes,
• Figure 8 shows another embodiment of the device in axial section and
• 9 shows a section along the line AA through FIG. 8.

As can be seen from FIGS. 1 to 3, a rolling stock guide tube FR consisting of partial tubes 2a and 2b is arranged in a fixed manner in the housing 1 in a housing 1. The nozzle head DK is placed on the input side E of the partial tube 2a and a centering projection ZA on the output side A of the partial tube 2b, behind which a deflection cover 4 is articulated in the housing 1 outside the tube part 2b. At a distance behind the outlet A of the partial pipe 2b, a wiping nozzle head ADK is also arranged in a stationary manner in the housing 1. The nozzle head DK and the scraper nozzle head ADK are connected to the water supply line ZL with a distribution pipe 5. A collecting trough 6, which leads to a drain 7, is arranged below the partial pipes 2a and 2b and the nozzle head DK of the centering projection ZA and the wiping nozzle head ADK.

As can be seen from FIG. 2, the nozzle head DK forms with a conical funnel attachment 8 and a thread-guided rolling stock inlet pipe 9, the conical tip 9a of which projects into the conical funnel attachment 8, an annular nozzle whose outlet cross section extends by turning the rolling stock inlet pipe 9 in the thread 8a of the nozzle head DK is changeable. The rotary drive consists of a worm wheel 10 placed on the rolling stock inlet pipe 9 and the worm shaft 11 meshing therewith, the drive of which is not shown. The water is fed to the nozzle head DK in the direction of arrow R4 from the distribution pipe 5 (FIG. 1). The conical funnel attachment 8 of the nozzle head DK is connected to the inlet E of the guide tube FR.

As shown in FIG. 3, the deflection cover 4 is arranged behind the output A of the wire guide tube FR in a manner not shown on the housing 1 about a pivot bearing DL, which is supported by springs or other elements, not shown, from the dash-dotted lines Deflection position in the passage position shown in full lines is pivotable. The wiping nozzle head ADK arranged behind this deflecting cover 4 in the direction of flow indicated by R6, like the nozzle head DK with a conical funnel attachment 12 and an inlet pipe 13, forms an annular nozzle whose outlet cross section is opposite to the direction of flow R6.

In the flow direction R6 in front of the deflecting cover 4 (FIG. 4), as is known, a pipe extension 14 is arranged at the outlet A of the rolling stock guide pipe, which has a pipe section 14a which tapers conically in the flow direction and an adjoining cylindrical outlet pipe section 14b (cf. . 4 and 5). Both pipe sections 14a and 14b have longitudinal grooves 16 open towards the pipe center axis, here with a cross section in the form of a circular section. The total passage cross-section of these longitudinal grooves 16 is approximately as large as the passage cross-section of the partial pipe 2a to be fed.

The device is operated according to the working method according to the invention as follows:
The rolling stock (the wire rod) D is brought from a feed tube, not shown, in the direction of arrow R6 (FIGS. 1 and 2) into the inlet tube of the nozzle head DK and further into the input side E of the wire guide tube FR. The cooling water passed through the distribution pipe 5 into the nozzle head DK passes through the outlet cross section of the ring nozzle formed by the conical tip 9a of the rolling stock inlet pipe 9 and the inner wall of the conical funnel attachment 8 into the considerably larger cross section behind this conical funnel attachment 8 a. By turning the rolling stock inlet pipe 9 in the thread 8a of the nozzle head DK, the conical tip 9a of the rolling stock Inlet pipe 9 axially shifted in the direction of entry R6 until the negative pressure generated by the entry of the water from the outlet cross section of the ring nozzle into the larger cross section of the conical funnel attachment 8 from the inner pipe part of the rolling stock inlet pipe 9 the air surrounding the wire rod D in of the pre-calculated subset. The resulting water-air mixture is then carried on in the rolling stock guide pipe FR, enclosing the outer circumference of the wire rod D, cools it down during the passage through the rolling stock guide pipe FR and, after leaving the rolling stock guide pipe FR in the outlet A, in a known manner through one of the direction of travel R6 inclined opposite water jet from the ring nozzle of the wiper nozzle head ADK from the peripheral surface of the wire rod D removed. The baffle cover 4 is in this operating phase in the passage position shown in full lines in FIG. 3. If the continuous wire rod D has left the exit A of the rolling stock guide tube FR and no further wire rod follows, the baffle cover 4 moves into the deflection position shown in dash-dot lines and causes the cooling water jet emerging from the output A of the rolling stock guide tube FR to be deflected downwards, while at the same time maintains or stabilizes the pressure conditions necessary for the passage of rolling stock through the rolling stock guide pipe FR. As already explained, deflecting the cooling water jet with the aid of the deflecting cover 4 prevents the cooling water jet from breaking through the opposing water jet of the wiping nozzle head ADK and thereby causing malfunctions or making it necessary for the water jet from the wiping nozzle head ADK to be considerably strengthened. which would result in a large additional water consumption.

The rolling stock guide pipe FR is, as can be seen from FIG. 1, divided into two partial pipes 2a and 2b. The outlet and the inlet of the two partial tubes 2a, 2b are coaxially opposite each other at the separation point at the front. The inlet of the second pipe section 2b is designed in a known manner as an inlet funnel and the outlet of the first pipe section 2a (see FIGS. 4 and 5) has pipe sections 14a and 14b which taper conically or cylindrically in the flow direction for centering the rolled material strand run. In order to ensure that the rolling stock D when it passes through these two pipe sections 14a and 14b is surrounded by a still sufficient jacket of the water-air mixture, the cooling effect of which is less than that of a water jacket consisting only of water, the passage cross section is through these two Pipe sections 14a and 14b of the tube extension 14 have been enlarged by longitudinal grooves 16.

An example of the cooling process when the wire rod passes through the rolling stock guide tube FR is indicated in a diagram in FIG. 6. The diagram shows the temperature profile of the outer circumference of the wire rod with curve 1, the average with curve 2 and the core with curve 3 and shows that the wire rod has already been cooled for 8 seconds after leaving the rolling stock guide tube FR so that one of the entire wire rod cross-section comprehensive reduction in temperature to 600 ° C has been achieved. However, the required low heat transfer coefficient can only be achieved with a water-air mixture with a high proportion of air and requires a very long cooling tube that is not suitable for rolling operation.

From the diagram according to FIG. 7 it can be seen that a similar result can be achieved with rolling stock guide tubes arranged one behind the other, the total length of which is only half as long as that of the rolling stock guide tube according to FIG. 6 (cooling in 4 seconds). Different heat transfer coefficients are set by different dimensioning of the proportions of air and water in the water-air mixture, so that a drop below the surface temperature below a material-dependent surface temperature is avoided.

8 and 9, the end 9b of the rolling stock inlet pipe 9 located outside the funnel attachment 8 of the nozzle head DK is mounted in the nozzle head DK so as to be longitudinally displaceable and secured against rotation by a locking bolt 17. It has an annular groove 18, into which slide cams 19 engage, which are arranged at the free ends of a pair of levers 20 which is seated on an axis 21 which is supported in bearings 22 in the housing 1 of the device. The axis 21 runs below the rolling stock inlet pipe 9 transversely to its central axis. With the axis 21, an adjusting lever 23 is fixedly connected to the piston-cylinder unit, not shown, by means of the longitudinal connection 25.

When the piston-cylinder unit is actuated and the pivotal movement of the actuating lever 23 brought about, the pair of levers 20 pivots in the same sense and by the same pivot angle. The rolling stock inlet pipe 9 is displaced in one direction or the other of the arrow F in the nozzle head DK via the sliding cams 19 engaging in the annular groove 18 and thus the outlet cross section of the nozzle head formed between the funnel neck 8 and the conical tip 9 of the rolling stock inlet pipe 9 DK changed.

When a plurality of nozzle heads are arranged in parallel next to one another, corresponding lever pairs can be arranged along this axis 21 in a manner not shown on the axis 21, the joint pivoting angle of which is then determined by the actuating lever 23 via the piston-cylinder unit.

List of reference numbers

• 1 housing
• 2a partial pipe
• 2b partial pipe
• 3 support angles
• 4 deflection angles
• 5 distribution pipe
• 6 collecting tray
• 7 drain
• 8a thread
• 8 funnel approach
• 9 Rolled-material inlet pipe
• 9b end (of the rolling stock inlet pipe 9)
• 9a conical tip
• 10 worm wheel
• 11 worm shaft
• 12 funnel approach
• 13 inlet pipe
• 14a tapered tube section
• 14 pipe socket
• 14b cylindrical outlet pipe section
• 15
• 16 longitudinal grooves
• 17 locking bolts
• 18 ring groove
• 19 sliding cams
• 20 pair of levers
• 21 axis
• 22 bearings
• 23 control lever
• 24th
• 25 steering connection
  
• E entrance / entrance side
• DK nozzle head
• FR rolling stock guide pipe
• A exit / exit side
• ZA centering approach
• ADK wiper nozzle head
• ZL water supply

Claims (16)

1. method for heat transfer between liquid media on the one hand and also liquid media or solid bodies on the other hand,
characterized,
that a container holding the liquid medium or a conduit for the flowing liquid medium or the solid body is acted upon on all sides by a flowing liquid medium to which a predetermined proportion of a gaseous medium is constantly mixed. 2. The method according to claim 1,
characterized,
that water is used as the liquid medium and air as the mixing medium. 3. The method according to claims 1 and / or 2,
characterized,
that the pressure of the flowing medium can be changed and fixed. 4. The method according to one or more of claims 1 to 3,
characterized,
that the solid body is moved at variable and definable speed. 5. Device for performing the method according to one or more of claims 1 to 4,
characterized,
that the conduit of the liquid flowing medium is an outer cylinder tube which coaxially comprises an inner cylinder tube which receives the flowing medium. 6. Application of the method according to one or more of claims 1 to 5 for temperature-controlled cooling of rolling stock during and after the roll deformation in water flow through the rolling stock guide tubes which supply the water with a presettable inlet pressure from an annular nozzle which is brought into a feed pipe and has a variable outlet cross section becomes,
characterized,
that the size of the outlet cross-section and / or the inlet pressure can be changed so that the ring nozzle (8, 9a) becomes effective as an injection nozzle, it produces mixtures of the water emerging from the outlet cross-section with air sucked in from the supply pipe with correspondingly different proportions of the mixture . 7. Working method according to claim 6,
characterized,
that the air fractions of the mixture are between 10 and 90 vol.%. 8. Working method according to claim 7, with guiding the wire rod through a plurality of wire guide tubes arranged one behind the other, each with adjustable ring nozzles,
characterized,
that the heat transfer numbers in the cooling tube, which can be set by the water / air mixture ratio, are 1500 to 35000 W / (m² · K). 9. Working method according to one or more of claims 6 to 8 with guiding the rolling stock through a plurality of rolling stock guide tubes arranged one behind the other, each having ring nozzles with an adjustable outlet cross section,
characterized,
that the cooling of the rolling stock in the individual successive guide tubes (FR) is effected with definable different settings of the respective outlet cross section of the ring nozzles (8, 9a) and / or the inlet pressure of the water. 10. Device for carrying out the working method according to one or more of claims 6 to 9,
characterized,
that behind the outlet (A) of the rolling stock guide tube (FR) through which the water-air mixture flows is an elastically supported, with the cross-section of the outlet (A) partially covered, ablanking cover (4) which can be brought into and out of the cover position. 11. Device for carrying out the working method according to claims 6 to 9 and according to claim 10,
marked by
the angular position of the deflecting cover (4) and the circumferential position of the rolling stock and detecting sensors, and a control unit connected downstream, which the Swivel angle of the deflection cover (4) controls so that its outer edge maintains a definable distance above the rolling stock (D). 12. Device for carrying out the working method according to claims 6 to 9 and according to claims 10 and / or 11,
characterized,
that the rolling stock guide tube (FR) is divided into two partial tubes (2a, 2b), the respective output and input of which are coaxially opposite one another at the end, the input of the second partial tube (2b) being known as an inlet funnel and the outlet of the first partial tube (2a) consists of a tube section (14a) which tapers conically in the direction of flow, which merges into a cylindrical tube section (14e), and both tube sections (14a, 14b) have groove-shaped longitudinal recesses (16) open towards the tube center axis, the overall cross section of which is dimensioned in this way is that the passage cross section of these two pipe sections (14a, 14b) is approximately equal to the passage cross section of the first partial pipe (2a). 13. Device for carrying out the working method according to claims 6 to 9 and according to one or more of claims 10 to 12,
marked by
a remotely controllable actuator (8a, 10, 11) for setting the outlet cross section of the ring nozzles (8, 9a). 1. Apparatus for carrying out the working method according to claims 6 to 9 and one or more of claims 10 to 12, which consists of a fixed nozzle head connected to the water supply with a conical funnel approach and a conically tapered start in this projecting and axially displaceable rolling stock. Inlet pipe exists,
marked by
to the end (9b) of the rolling stock inlet pipe (9) located outside the funnel extension (8) of the nozzle head (DK), about a lever (20) connected to an actuator and rotatably mounted at a distance transversely to its central axis. 15. The apparatus according to claim 14,
characterized,
that the levers (20) engage as a pair of levers with slide cams (19) arranged at their free ends in an annular groove (18) arranged at the end of the rolling stock inlet pipe (9) and with their other ends with the top or bottom of the rolling stock inlet pipe (9 ) mounted axis (21) are firmly connected, which carries at one free end a pivoted to a piston-cylinder unit control lever (23). 16. Device according to claims 14 and / or 15,
marked by
a plurality of nozzle heads (DK) arranged parallel to one another, the rolling stock inlet pipes (9) of which are connected to the actuator via levers (20) rotatably mounted about a common axis (21).

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