EP3546086A1 - Method for continuously casting a metal strand using a mould and a casting stone - Google Patents

Abstract

The invention relates to a device for continuously casting at least one metal strand (1), in particular at least one rolling ingot of a melt of an aluminum alloy with at least one mold (2), at least one casting table (3) lowerable relative to at least one mold (2) and at least one Angular stone (4), wherein the at least one sprue (4) is associated with a respective mold (2) and is arranged on the at least one lowerable casting table (3). The object to provide a device for continuously casting a metal strand, in particular a rolling ingot from a melt of an aluminum alloy, which provides an improved possibility of intervention in the continuous casting process and this permanently ensured in production, is achieved in that the at least one sprue (4) at least one distance sensor (5, 6, 7) which is arranged in the vicinity of or on the center line (9a) extending perpendicularly to the broad side of the associated mold, preferably in the center (10) of the sprue surface (11) of the sprue (4) and the at least one Distance sensor (5, 6, 7) can measure the distance between Angusssteinoberfläche (11) and the sprue stone (4) facing surface of the Metallstrangfußes during the continuous casting.

Description

The invention relates to a device for continuous casting of at least one metal strand, in particular at least one rolling ingot of a melt of an aluminum alloy with at least one mold, at least one lowerable relative to at least one mold casting table and at least one sprue, wherein the at least one sprue is associated with a respective mold and is arranged on the at least one lowerable casting table. Moreover, the invention relates to a method for continuously casting at least one metal strand, in particular a rolling ingot from a melt of an aluminum alloy using the device according to the invention.

In the continuous casting of metal strands, in particular rolling bars consisting of an aluminum alloy, the molten metal is passed through a mold and cooled by primary and secondary coolant to a metal strand or ingot. In the melt flow direction below the mold, the metal cooled by primary and secondary coolant is taken up by a sprue. The sprue stone arranged on a casting table is lowered during continuous casting after casting of the metal strand foot by lowering the casting table, so that a metal billet or ingots can be produced. The metal strand cools further in the first cast metal strand foot area. The casting of the metal strand, ie the casting of the metal strand foot in the sprue stone, is one of the critical phases of metal casting, since the metal strand foot experiences a strong cooling from the melt to the solid state and shrinkage processes occur. The result is a characteristic Metallstrangfußverformung. In aspect ratios of the narrow side to broad side of the metal strand of 1/3 and smaller (eg 1/4), as they occur in rolling bars, for example, the narrow sides of the sprue arch against the continuous casting towards the mold.

The warping worsens the stability of the metal strand in the sprue. This can lead to excessive tilting of the metal strand. The metal strand can also "tilt" in the mold during tilting and get stuck in the mold, which can lead to great problems in the casting without intervention in further continuation of the casting process. The warping of the narrow sides of the metal strand can also lead to constrictions on the narrow sides of the rolling billet, so that liquid metal melt can escape from the interior of the metal strand on the narrow sides.

In order to measure the warping of the narrow sides of the metal strand during the casting of aluminum alloys, for example, from the book "Continuous Casting", E. Lossack, 1986, tentatively freeze two steel wires as inductive transducers on the narrow side in Barrenfuß when casting. The warping of the narrow sides of the metal strand leads to a lifting of the underside of the Metallstrangfußes and thus to lift the frozen steel wires. The change in position of the steel wires is measured inductively. In principle, this can also be used to measure the tilting of the billet.

A problem with the known measuring device is that a "sticking" of the metal strand or billet can be detected relatively late. So far, the focus has been on the character of the warping and not on a snagging of the metal strand. The intervention in the casting process was therefore not timely. In addition, the known measuring device was previously not suitable for production, but has been used only for individual measurements. It thus lacks the production control. The ambient conditions when casting metal strands, in particular of aluminum strands and rolling bars, are particularly problematic for continuous use of corresponding sensors due to the high temperatures, possible metal splashes and the presence of water cooling. However, a stable measurement with only a low failure risk is the prerequisite for use in production. About that In addition, so far also a repeatable accurate positioning and ease of use of the measuring device was not given. The known measuring device is in need of improvement in view of use in production.

Proceeding from this, the object of the present invention is to propose an apparatus for continuous casting of a metal strand, in particular of a rolled bar from a melt of an aluminum alloy, which offers an improved possibility of intervention in the continuous casting process and also guarantees this permanently in the production operation. In addition, the invention has the object to provide a method for continuously casting a metal strand, in particular a rolling ingot from a melt of an aluminum alloy using the device according to the invention.

According to a first teaching of the present invention, the above-described object is achieved for a device for continuously casting at least one metal strand, in particular at least one rolling ingot of an aluminum alloy melt, that the at least one sprue stone has at least one distance sensor which in the vicinity or on the centerline extending perpendicular to the broad side of the associated mold, preferably in the geometric center of the sprue surface of the sprue, and the at least one distance sensor capable of measuring the distance between the sprue surface and the facing surface of the metal runner during continuous casting.

According to the invention, placing the distance sensor "in the vicinity" of the center line of the sprue surface running perpendicular to the broad side of the mold means that the distance sensor is arranged at a maximum of +/- 0.5 cm at right angles away from the center line of the sprue surface. By the center line of the sprue surface is meant the imaginary axis of symmetry of the sprue surface which divides the sprue surface into two symmetrical portions towards the narrow sides.

By using a centerline extending in the vicinity of or perpendicular to the broad side of the associated mold, preferably in the geometric center of the sprue surface of the sprue, it is achieved that the distance between the sprue surface of the metal runner in the center of the metal runner to the sprue during of the continuous casting can be measured. The distance of the center of the metal strand foot to the sprue stone changes almost independently of the warping of the narrow sides of the metal strand and thus allows a check whether the metal strand has optionally remained stuck in the mold. This can be felt by rapidly changing the distance when lowering the sprue over the casting table after casting the metal string foot. The device according to the invention therefore makes it possible to detect a "sticking" of the metal strand or rolling bar particularly early and thus to intervene early in the continuous casting process.

According to an embodiment of the device, the at least one distance sensor preferably measures the distance between the sprue surface and the surface of the metal strand foot facing the sprue during the continuous casting, preferably inductively. The at least one inductive distance sensor can be made very robust and simple, so that precise measured values can be provided even under the problematic environmental conditions of the device.

In order to better monitor the continuous casting process, especially in the critical gating phase, the at least one gating block has at least two further, preferably inductive distance sensors, which are arranged at a distance from the center line, preferably symmetrically to the center line. By at least two other distance sensors, the warping of Metallstrangfußes and possibly also a tilting of the metal strand can be measured on the sprue during continuous casting. Already at the beginning of this Error can be stopped via the device, for example, the continuous casting process. In addition, based on the data of the other distance sensors, the continuous casting process can be selectively controlled by engagement in the primary and secondary coolants. For example, the inflow of the amount of cooling water or the water distribution can be specifically changed, reduced or increased on the broadsides. Alternatively, the cooling can also be adjusted indirectly by changing the lowering speed of the casting table or by a combination of changed water quantity, water distribution and lowering speed.

Particularly preferred here is the use of at least three inductive distance sensors, which are preferably arranged on the parallel to the broad side of the mold extending symmetry axis of Angußsteinoberfläche and thus can determine the position of the metal strand or the expression of the warping very precisely.

If at least one distance sensor is provided which can transmit the measurement data wirelessly, in particular telemetrically, to an evaluation unit, measurement data from the continuous casting process can be reliably transmitted despite the ambient conditions in the production area of the casting installation. The high reliability of the telemetric transmission, especially in digital form, allows reliable monitoring of the start of the continuous casting process. In general, wireless transmission of the measured values in the sense of the present patent application encompasses all possible forms of non-wired data transmission. It is conceivable, for example, the integration of sensors into an existing wireless network and the transmission of the measured values by certain network or other transmission protocols, such as Bluetooth. Due to the very demanding environmental conditions of the sensors in the production area, the simplest possible telemetric transmission of the measured data is advantageous. In telemetric data transmission, only the recorded measurement data from the sensor wirelessly, usually digital, to a Receiving station transmitted, which optionally prepared this and forwarded to an evaluation unit.

If, according to a further embodiment of the device according to the invention, at least one distance sensor is provided which has a measurement data acquisition unit and a separate control unit, the measurement data acquisition unit can be made particularly robust and simple and be separated from a more sensitive control electronics. The measurement data acquisition unit is used only for the acquisition of the measured values and forwarding to the separate control unit, which can also be used, for example, to calibrate the measurement data acquisition unit. As a result, the reliability of the distance sensor is significantly improved. The separate control unit may, for example, be located in a better protected location, e.g. be arranged below the casting table to reliably perform a processing of the measurement data, their example wireless transmission and also the control of the measurement data acquisition unit.

According to a further embodiment of the device according to the invention, a rechargeable electric power supply for the distance sensors, for example in the form of a rechargeable battery, is provided, which is preferably arranged below the casting table. Below the casting table, the electrical energy supply is particularly well protected against metal splashes and extremely high temperatures, which emanate from the metal strand. Rechargeable electrical power supplies allow the distance sensors without electrical wiring to operate, which would be problematic in production due to the lowerable casting table. The charging of the electrical power supply can be done for example in a certain position of the casting table, so that at the beginning of each Stranggießprozesses enough electrical energy to operate the distance sensors is present.

If, according to a further embodiment of the device, at least one inductive distance sensor is provided, whose measuring data recording unit has a Measuring transducer recording, wherein the transmitter recording can fix the transmitter via a frictional connection, it is possible to replace the transmitter, for example, by overcoming the frictional connection between the transmitter recording and transmitter without replacing the entire sensor. At the same time, the frictional connection between the sensor holder and the transmitter ensures that a movement of the transmitter due to the frictional connection is transferred into a movement of the sensor holder. The movement of the sensor recording can serve, for example, to generate the measured value in a measuring unit of the distance sensor.

Preferably, according to a further embodiment of the device according to the invention, the transmitter is designed as a steel wire. The sensor housing facilitates the use of transmitters in the form of steel wires by allowing the steel wire to be passed to a measuring unit via the sensor holder after freezing the steel wire in the metal leg and, on completion of the continuous casting, to easily remove the steel wire from the sensor holder Overcoming the frictional connection, for example, when removing the cast metal strand or rolling bar can also be removed from the transmitter recording.

An improvement in the measurement accuracy of the distance sensors is achieved in accordance with a further embodiment of the device in that means for mechanical or magnetic provision of a frictional connection with the transmitter are provided in the transmitter recording. Both possibilities, mechanical and magnetic, have the advantage that they are particularly easy to implement and can withstand high temperatures at the same time. Preferably, the sensor holder for simplified installation additionally has a funnel-shaped opening for the transmitter, for example a steel wire, in order to arrange this in the transmitter receptacle.

To provide a magnetic adhesion, for example, ring magnets may be provided in the transmitter receptacle, which surround the steel wire and fix the steel wire frictionally by the magnetic field prevailing in the ring magnet. Here, magnets, for example samarium-cobalt magnets can be used, which provide even at high temperatures of more 250 ° C still strong enough magnetic fields for traction.

As means for providing a mechanical frictional connection, for example, rings made of elastic material, for example made of rubber, silicone or Teflon come into consideration, which can surround the steel wire and fix in the transmitter recording.

According to a further embodiment of the device according to the invention is provided as means for mechanically providing the frictional connection with the steel wire at least one ring surrounding the steel wire made of an elastic material in a blind hole of the sensor recording, wherein means are provided for applying pressure to the at least one ring in the axial direction of the steel wire , By applying pressure to the at least one ring this is elastically deformed. Due to the arrangement in the blind hole of the at least one ring is thereby deformed substantially into the interior of its ring opening, so that the ring opening of the at least one ring is significantly reduced and the steel wire is thereby clamped mechanically via a frictional connection.

Preferably, the means for applying pressure can be provided via a screw sleeve which has an opening for the steel wire and which can be screwed into the transmitter receptacle in order to exert pressure on the at least one elastic ring. By screwing the screw sleeve, a frictional connection between the transmitter recording and transmitter, in particular a steel wire, very accurately controlled and made possible in a simple manner.

The transmitter receptacle preferably has a further bore at the end opposite the transmitter, with which it can be positively and / or non-positively connected to the measuring unit in a simple manner, preferably screwed to the measuring unit. This allows a simple connection of the transmitter with the measuring unit of the distance sensor and at the same time allows removal of the transmitter at the conclusion of continuous casting.

The device preferably has a display device on which the measured values of the distance sensors, preferably of all distance sensors, are represented graphically, numerically or by signal colors. The operators of the caster can thus easily monitor the beginning of the casting process even when multiple casting several metal strands or ingots and intervene early in the casting process.

Finally, according to a further embodiment, the device has a plurality of molds and a plurality of associated sprue stones, which are arranged lowerable on a casting table, wherein the molds and the associated sprues have the same and / or different formats.

According to a second teaching of the invention, the above-indicated object for a method for continuously casting metal strands, in particular rolling bars, is achieved in that at least one distance sensor measures the distance between the sprue surface and the facing of the sprue surface of the Metallstrangfußes during the continuous casting and the at least one Distance sensor is arranged in the vicinity of or on the perpendicular to the broad side of the mold extending center line of the sprue surface of the sprue in the sprue.

Surprisingly, the use of at least one proximity sensor on or near the centerline of the sprue surface of the sprue achieved that a "snagging" of the metal strand during continuous casting can be measured directly by changing the distance between the sprue surface and the facing to the sprue surface of the metal strand foot. It was recognized that with the method according to the invention the "sticking" of the metal strand can be detected much earlier and countermeasures can be initiated than previously. If the distance sensor arranged in the vicinity of or on the center line of the sprue surface detects a change in distance between the metal runner and the sprue surface, it can be immediately concluded, for example, that the metal strand is "stuck". Even very small differences in the speed of the Metallstrangfußes relative to the casting table are registered. The distance sensor is preferably arranged in the geometric center of the sprue surface, ie in the center of the center line, thereby achieving maximum decoupling of the distance measurement from warping on the narrow sides. The change in distance can be detected in the geometric center with almost no overlapping of a change in distance due to a warping of the narrow sides of the metal bar or rolling bar. A snagging of the metal strand can thus be recognized much earlier and safer. This can be used, for example, with the primary and secondary coolants influence early on the "snagging" or abort the casting process early.

According to a preferred embodiment of the method according to the invention, the distance sensors measure the distance between the Angussteinoberfläche and pointing to Angussstein surface of the Metallstrangfußes during continuous casting inductively. Inductive distance sensors can be made very robust and easy. They can therefore provide accurate readings even in problematic environments.

According to another embodiment, measuring at least two further distance sensors, which are arranged at a distance from the center line, preferably symmetrically to the center line, during the casting of the metal strand the distance between the Angusssteinoberfläche and facing the sprue surface of the metal strand foot, in addition to the snagging of the metal strand and the warping of the narrow sides of the Metallstrangfußes, or the Rollbarrenfußes can be measured simultaneously. In addition to the snagging, which is first determined by the at least one distance sensor arranged symmetrically on the center line or in the vicinity of the center line of the sprue surface, asymmetrical warping or excessive warping of the narrow sides can also be measured via the further distance sensors, so that the primary - and secondary coolants of the mold influence on the continuous casting process can be taken to eliminate the errors.

It has proven particularly advantageous, according to a further embodiment of the method according to the invention during continuous casting, to visibly display the measurement results of at least one distance sensor, preferably all of the distance sensors used. The display of the measurement results of the distance sensors can preferably be made available only by displaying the measurement results or else by graphically processing the measurement results, for example in the form of a bar chart in the production control system, but in particular directly at the casting plant. The provision of the measurement results either in the production control system and / or directly at the casting plant allows a very rapid intervention in the casting process, which was previously not possible.

In addition, it is conceivable to provide a particularly intuitive graphical processing of the measurement results in the production environment as an indication, for example by translating the measured values into signal colors. Thus, the representation of the measured values could be carried out with traffic light colors, e.g. Green for good, yellow for still acceptable and red for discontinuation of the casting process.

According to a further embodiment of the method according to the invention, the measurement data of at least one distance sensor to an evaluation unit is wireless, preferably transmitted telemetrically during continuous casting.

If, in accordance with a further embodiment of the method, the continuous casting process is controlled as a function of the measured data of at least one distance sensor evaluated in an evaluation unit, the continuous casting process, for example the primary and secondary coolants or, for example, the casting speed of the molten metal can be changed to the measured data on the basis of the determined distance sensor data and a control of the continuous casting process are performed. As a result, can be acted much earlier than before on the continuous casting process to avoid errors during continuous casting or specifically counteract this.

Fig. 1

in einer schematischen Schnittansicht eine Vorrichtung zum Stranggießen eines Metallstrangs gemäß einem ersten erfindungsgemäßen Ausführungsbeispiel,

Fig. 2

den Angussstein des Ausführungsbeispiels aus Fig. 1 in vergrößerter Seitenansicht,

Fig. 3

eine Draufsicht auf die Angusssteinoberfläche des Angriffssteins aus Fig. 2,

Fig. 4

in einer perspektivischen Darstellung die Angusssteine sowie den Gießtisch eines weiteren Ausführungsbeispiels der erfindungsgemäßen Vorrichtung mit mehreren Angusssteinen,

Fig. 5

in einer weiteren perspektivischen Darstellung die Unterseite des Gießtisches des Ausführungsbeispiels aus Fig. 4,

Fig. 6a, 6b

in schematischen Schnittansichten zwei Ausführungsbeispiele von Messwertgeberaufnahmen induktiver Abstandssensoren sowie

Fig. 7

ein Ausführungsbeispiel einer grafischen Anzeigevorrichtung.

In addition, the invention will be explained in more detail with reference to embodiments in conjunction with the drawings. In the drawing shows

Fig. 1

in a schematic sectional view of an apparatus for continuously casting a metal strand according to a first embodiment of the invention,

Fig. 2

the sprue of the embodiment Fig. 1 in enlarged view,

Fig. 3

a plan view of the sprue surface of the attacking stone Fig. 2 .

Fig. 4

3 shows a perspective illustration of the sprue stones and the casting table of a further exemplary embodiment of the device according to the invention with a plurality of sprue stones,

Fig. 5

in a further perspective view of the underside of the casting table of the embodiment Fig. 4 .

Fig. 6a, 6b

in schematic cross-sectional views of two embodiments of transducer recording inductive distance sensors and

Fig. 7

an embodiment of a graphic display device.

Fig.1 1 shows, in a schematic sectional view, an exemplary embodiment of a device according to the invention for continuously casting a metal strand 1, in particular a rolling ingot 1 from a melt of an aluminum alloy with at least one mold 2, at least one casting table 3 lowerable relative to at least one mold 2 and at least one sprue stone 4, which is assigned to the mold 2 and is arranged on the lowerable casting table 3. In continuous casting, molten metal from an aluminum alloy is passed through the mold 2 and cooled via the mold 2 with its primary and secondary coolants, not shown. The cooled metal forms the shape of a strand having a generally rectangular cross-sectional area which is poured into the gate 4.

By not shown primary and secondary coolant is used in casting the molten metal in Fig. 1 illustrated Metallstrangfuß 12, which designates the standing with the sprue 4 in contact area of the metal strand, initially cooled. When the casting table 3 is lowered, shrinkage processes due to the state of aggregation of the metal due to the further cooling process of the metal extrusion 12 in contact with the casting block 4 occur, so that the metal extrusion 12 deforms during cooling.

The in Fig.1 shown sprue 4 has three distance sensors 5, 6, 7, wherein a distance sensor 5 in the vicinity of or on the perpendicular to the broad side 8 of the mold 2 extending center line 9, preferably in the center 10 of the sprue surface 11 of the sprue is arranged. The distance sensors 5,6, 7 of in Fig.1 illustrated embodiment measure the distance between the Sprue stone surface 11 and facing the sprue 4 surface of the Metallstrangfußes 12 during continuous casting.

In Fig. 2 is the in Fig. 1 shown Angussstein 4 again. Additionally shows Fig. 3 a schematic plan view of the sprue surface 11 of the sprue 4 from Fig. 2 , To recognize are in Fig. 2 and Fig. 3 the three distance sensors 5, 6, 7, wherein the distance sensor 5 is arranged exactly on the center line 9, that is, in the geometric center 10 of the sprue surface 11. The two further distance sensors 6, 7 are arranged at a distance from the center line 9, preferably symmetrically to the center line 9. In the Fig. 3 represented position of the distance sensors 5, 6, 7 represents a preferred embodiment of the arrangement of the distance sensors. According to this embodiment, the distance sensors 5, 6, 7 arranged on the parallel to the broad side 8 extending center line 9b of Angußsteinoberfläche 11. The center line 9b corresponds to the axis of symmetry of the sprue surface 11, which runs parallel to the broad side 8 of the mold.

If the metal strand 1 now remains hanging during continuous casting, this can be measured directly via the distance sensor 5. The distance sensor 5 arranged in the center of the sprue surface 11 measures the distance from the sprue surface to the metal strand foot or the surface of the metal strand facing the sprue 4 almost without being affected by shrinkage processes which always occur in the direction of the narrow sides. This makes it possible to intervene as early as possible in the continuous casting process.

The two laterally arranged distance sensors 6, 7 detect the warping of the Metallstrangfußes 12 due to the cooling of the metal on the narrow sides of the strand and can be evaluated to determine the warping of the narrow sides of the Metallstrangfußes 12. If the warping, for example, uneven, it may lead to a tilting of the metal strand, or rolling ingot 1. Due to the additional use of these two distance sensors results Another way to monitor the casting process and possibly intervene to prevent tilting or snagging of the metal strand or to stop the continuous casting process. The distance sensors 6,7 are preferably arranged symmetrically at a distance from the center line 9, which runs perpendicular to the broad side 8 of the mold 2, as this Fig. 3 shows.

In the Fig. 2 Distance sensors 5, 6, 7 shown transmit the measurement data wirelessly, preferably telemetrically to an evaluation. For this purpose, the distance sensors 5, 6, 7 are each divided into a measurement data recording unit 14, 15, 16 and control units 17, 18, 19. The measurement data recording units 14, 15, 16 are used in this embodiment only the measurement data acquisition and have no additional control electronics. As a result of the separation of control unit 17, 18, 19 and measurement data acquisition unit 14, 15, 16, it can be configured in a particularly simple and robust manner, so that precise measured values can be determined despite high ambient temperatures. The control units 17,18,19, despite the environmental conditions at the location of the measurement data recording units 14,15,16 safely ensure their control functions, since the sensitive electronics can be placed in sheltered locations. The control units 17, 18, 19 can be used, for example, for calibrating the measurement data acquisition units 14, 15, 16 and / or for data processing or data transfer steps. The data transmission preferably takes place wirelessly, which reduces the outlay for the device according to the invention and brings about advantages with respect to otherwise possibly wear-prone cabling of the moving casting table.

In Fig. 4 is now a casting table in a perspective schematic representation with a plurality of sprue stones 4 shown. In the perspective view, the sensors 23, here designed as steel wires, can be seen. Each sprue stone 4 has in the embodiment of Fig. 4 Recordings for the distance sensors and corresponding feedthroughs for the transmitters 23. In the Fig. 4 The device shown is for casting a total of four metal strands formed, which, for example, here have an identical format. It is also conceivable, however, to cast a plurality of metal strands with different formats with the device according to the invention in order, for example, to optimally exploit the furnace capacity of melting furnaces.

In Fig. 5 is the bottom of the casting table of the embodiment Fig. 4 shown in a schematic perspective. It can be seen in the embodiment in Fig. 4 In addition, means for charging the electrical power supply 20a, as already described in US Pat Fig. 4 , which, for example, recharges contactlessly the energy supply 20 of the distance sensors in a specified position of the casting table 3. For this purpose, an elaborate and error-prone cable guide in the region of the casting table 3 can be replaced by an inductive energy transmission. By arranging the rechargeable power supply 20 below the casting table, it can be safely protected from the ambient conditions of the continuous casting process.

The Fig. 6a and 6b show now two different embodiments of inductive distance sensors 5, 6, 7. Preferably, the distance sensors 5, 6,7, a measurement data recording unit 20, which consists of a measuring unit 21 and a sensor recording 22. The transmitter receptacle 22 is engaged with the measuring unit 21. The transmitter 23 is also connected to the Meßwergeberaufnahme 22 via a frictional engagement, so that the transmitter 23, in this case designed as a steel wire, for example, after freezing in the Metallstrangfuß 12 a change in position by a warping of Metallstrangfußes 12 or snagging of the metal strand 1 at can pass on the measuring unit 21 and this can thus measure the distance between Metallstrangfußoberfläche and Angusssteinoberfläche 11.

In the transmitter recording 22 means 24, 25 are provided which provide a positive connection with the transmitter 23 mechanically or magnetically. On the one hand, the non-positive fixing allows the positional change of the transmitter 23 to be forwarded to the measuring unit 21; on the other hand, however, the transmitter 23 can be removed from the sensor holder when the force is overcome. This is usually done when removing the metal strand 1 after completion of the continuous casting. The transmitter recording is then ready to receive the next transmitter 23 ready. The preparations of the sprue 4 for a new continuous casting process are thereby particularly simple. All that needs to be done is to place a new steel wire as the transducer in the sprue stone 4.

For a mechanical provision of the frictional connection between the transmitter 23 and the transmitter receptacle 22 is according to Fig. 6b at least one surrounding the steel wire ring of an elastic material, for example, consisting of rubber, Teflon or silicone in a blind hole 24a of the sensor recording 22 is provided. Via means 26 for exerting pressure on the at least one ring 24a in the axial direction of the steel wire, pressure can be exerted on the at least one ring 24, here on a plurality of rings, and the ring opening of the in Fig. 6b shown rings 24 are narrowed. The steel wire 23 is thus clamped mechanically via a frictional connection in the transmitter receptacle. The means 26 for applying pressure to the elastic rings 24 is formed, for example, as a threaded sleeve 26, which has an opening for insertion of the steel wire 23 and at the same time can be screwed through a thread in the blind hole 24a of the sensor holder 22. When screwing in the screw sleeve, a pressure in the axial direction of the steel wire is exerted on the rings 24 and the steel wire is purposefully clamped in the measuring device holder.

The distance sensors 5, 6, 7 are preferably designed as so-called LVDT (Linear Variable Differential Transformer) sensors. The measuring unit 21 may preferably be fixedly coupled to an armature of an LVDT sensor, so that the movement of the measuring unit directly causes a movement of the armature of the LVDT sensor. The armature of the LVDT sensor consists of a non-magnetic coupling, which can be coupled to the measuring unit 21 and a ferromagnetic core, which is moved between coil arrangements in the sensor has. This generates the measuring signal. LVDT sensors are very robust distance sensors and can guarantee accurate distance measurement even in difficult environmental conditions.

An alternative possibility to transmit the movement of the steel wire 23, which is to freeze in the metal extrusion 12, to the measuring unit 21, by a magnetic adhesion of the transmitter 23, so the steel wire, and the measured value recording 22, for example by the use of annular samarium cobalt -Magnets 25 can be achieved. These magnets ensure that the steel wire 23 is held at high ambient temperatures via a magnetic frictional connection with the transmitter recording, so that its movement can be passed on to the measuring unit 21. For better insertion of the steel wire 23, the transmitter receptacle 22 in Fig. 6a a funnel-shaped opening on. A corresponding opening can also be found in the screw sleeve of the Fig. 6b be provided to facilitate insertion of the steel wire. Via the further bore en27 provided on the sensor holder 22, the sensor holder 22 can be screwed onto the measuring unit 21, which then transmits the movement of the steel wire 23 into a movement of the measuring unit 21.

Preference is given, as in Fig. 7 is shown, the measured values of the distance sensors 5, 6, 7 graphically, for example, as a bar chart shown to give the operators of the casting plant information about the course of Angießphase the continuous casting. For example, the bar chart may have different colors for measured values in the nominal range and outside the nominal range. The display device off Fig. 7 can also be done in the form of a traffic light or other intuitively accessible representation. In any case, a visible representation in the casting plant is advantageous in order to be able to directly control the course of the casting. The measured values for controlling the casting process can also be used in the control station of the casting plant.

When using the device according to the invention, the distance between the metal extrusion 12 and the sprue surface 11 can be monitored during continuous casting, for example in the control room of the casting plant, so that the continuous casting process can be controlled as a function of the measurement data of the at least one distance sensor evaluated in an evaluation unit. This allows early intervention in the continuous casting process when faults occur and, for example, via primary and secondary coolants, the defects of uneven warping and / or snagging of the metal strand can be avoided. As a result, a significantly improved continuous casting process is achieved.

Claims (16)

Apparatus for continuously casting at least one metal strand (1), in particular at least one rolling ingot of a melt of an aluminum alloy with at least one mold (2), at least one casting table (3) lowerable relative to at least one mold (2) and at least one sprue (4) wherein the at least one sprue stone (4) is in each case associated with a mold (2) and on which at least one lowerable casting table (3) is arranged,
characterized in that
the at least one sprue stone (4) has at least one distance sensor (5, 6, 7) which is located in the vicinity of or perpendicular to the broad side of the associated mold center line (9a), preferably in the center (10) of the sprue surface (11) of the Angular stone (4) is arranged and the at least one distance sensor (5, 6, 7) can measure the distance between the sprue surface (11) and the sprue stone (4) facing surface of the Metallstrangfußes during the continuous casting. Device according to claim 1,
characterized in that
the at least one sprue stone (4) has at least two further distance sensors (6, 7) which are arranged at a distance from the center line (9a), preferably symmetrically to the center line (9a). Apparatus according to claim 1 or 2,
characterized in that
at least one distance sensor (5, 6, 7) is provided, which can transmit the measurement data wirelessly, in particular telemetrically to an evaluation unit. Device according to one of claims 1 to 3,
characterized in that
at least one distance sensor (5, 6, 7) is provided, which has a measured data recording unit (14, 15, 16) and a separate control unit (17, 18, 19). Device according to one of claims 1 to 4,
characterized in that
a rechargeable electric power supply (20) for the distance sensors (5, 6, 7) is provided, which is arranged below the casting table (3). Device according to one of claims 1 to 5,
characterized in that
at least one inductive distance sensor (5, 6, 7) is provided, the measured data recording unit (14, 15, 16) has a Meßgebergeberaufnahme (22), via the Meßgebergeberaufnahme (22) a transducer (23) can be fixed via a frictional connection. Device according to claim 6,
characterized in that
the transmitter (23) is designed as a steel wire. Apparatus according to claim 6 or 7,
characterized in that
the transmitter recording (22) comprises means for mechanical or magnetic provision of a frictional connection (24, 25) with the transmitter (23). Device according to claim 8,
characterized in that
at least one ring (24) made of an elastic material is provided as means (24) for the mechanical provision of the frictional connection, wherein at least one ring (24) is arranged in a blind hole (24a) of the transducer receptacle (22) and the at least one ring is the steel wire (23) in the sensor housing at least partially surrounds and means (26) for applying pressure to the at least one ring (24) in the axial direction of the steel wire (23) are provided. Device according to claim 9,
characterized in that
Pressure applying means via a screw sleeve (26) are provided, which has an opening for the steel wire (23) and which can be screwed into the Meßgebergeberaufnahme (22). Device according to one of claims 6 to 10,
characterized in that
the transmitter receptacle (22) has a further bore (27) at the end opposite the transmitter (23), with which it can be screwed to a measuring unit (21) in a form-locking and / or force-locking manner, preferably with the measuring unit (21). Device according to one of claims 1 to 11,
characterized in that
the device has a display device (28) on which the measured values of the distance sensors (5, 6, 7), preferably of all distance sensors, are represented graphically, numerically or by signal colors. Device according to one of claims 1 to 12,
characterized in that
the apparatus comprises a plurality of molds (2) and a plurality of associated sprue stones (4) which are mounted on a casting table (3) are arranged lowerable, wherein the molds (2) and the associated sprue stones (4) have the same and / or different formats. Method for continuously casting at least one metal strand (1), in particular at least one rolling ingot from a melt of an aluminum alloy, using a device according to one of the claims 1 to 13,
characterized in that
at least one distance sensor (5, 6, 7) measures the distance between the sprue surface (11) and the surface of the metal strand foot (12) facing the sprue (4) during continuous casting, the at least one distance sensor (5, 6, 7) in near or on the perpendicular to the broad side of the mold (2) extending center line of the sprue surface (11) of the sprue in the sprue (4) is arranged. Method according to claim 14,
characterized in that
During the continuous casting, the measurement results of at least one distance sensor (5, 6, 7), preferably all inserted distance sensors, are visibly displayed or displayed. Method according to claim 14 or 15,
characterized in that
the continuous casting process is controlled at least as a function of the measured data of at least one distance sensor (5, 6, 7) evaluated in an evaluation unit.

Images