EP1464421B1 - Molten metal level sensor of a continuous casting mould and its method of operation - Google Patents

Abstract

The manipulator is fixed with a sensor (1) using a detachable connection, especially a clamp on a mold (2) or its water tank (12). The sensor is coupled with the movement of the mold. An independent claim is also included for a process for operating the manipulator.

Description

The invention relates to a sensor for detecting the filling level of liquid metal in the mold of a continuous casting with a manipulator for guiding the sensor, wherein the manipulator with the sensor arranged on it using a detachable connection, in particular by means of clamping on or on the mold or is attached to the water tanks and the sensor is thus coupled to the movements of the mold. The invention also relates to a method for operating the sensor.

The mold level control of in particular thin slab continuous casting molds can be controlled by means of a sensor which projects from above into the mold opening. After completion of the necessary preparations of the mold for the casting process, the sensor is swiveled manually or automatically into the interior of the mold shortly before the start of casting. In the event of accidents that could lead to its damage, it is immediately swung out of the danger zone.

For example, US Pat. No. 4,186,792 discloses a continuous casting control apparatus using eddy current measuring equipment for determining the distance of the melt from a reference point of the mold, which generates a signal by means of non-contact measurement, the measuring apparatus being mounted tightly above the metal mirror. According to another embodiment, the measuring device for eddy current measurement is arranged vertically adjustable close to the surface of the liquid metal, in accordance with changes the metal mirror, the measuring device is always kept at the same distance from this. A potentiometer disposed thereon generates a signal indicative of the distance and transmits it to a recorder or uses it to adjust the feed or discharge amount of melt by means of a monitoring and control device to keep the metal level constant.

The document EP 0 067 668 B1 describes an apparatus for measuring a change in a predetermined direction of a surface position of a metal mass. The device comprises a magnetic-based metal sensor, a drive device for the sensor, a follower device that causes the sensor to follow the change in the position of the metal mass, and devices for generating a position signal for a momentary position of the sensor on a movement path, furthermore A disturbance signal storage means for measuring a disturbance component in the output of the sensor due to factors other than the change of the surface position of the metal mass, and a correcting means for correcting the difference signal by the disturbance component stored in the storage means to activate the drive means with this corrected signal.

The document WO 00/38858 relates to a method and a device for detecting and regulating the level of a molten metal in a mold, in particular for a continuous casting plant for steel, wherein the melt from a feed opening having a closable bottom opening can be supplied to the mold via a dip tube, with a measuring element, which is vertically movable in the free space of the mold can be introduced. In this case, the level measuring element is connected via a first signal line to a computer which is connected via a first control line with a first actuator in connection, to which a boom is attached, at the head end of the level measuring element is mounted. On the boom a Positonsmessfühler is provided, which has a second signal line is connected to the computer, which communicates via a second control line with a second actuator, which is associated with a shut-off device for closing the bottom opening of the Zuführgefäßes.

The document JP 08 168 860 A describes a method for measuring the current surface level of liquid steel in a mold of a continuous casting plant. The change distance is measured with a height indicator. Laser beam sensors are arranged to settle the position when observing the height or depth mark of the measuring rod. Casting powder with an unmelted and a molten layer cover the molten steel. The output of the altitude measuring device is input to an amplifier. A drive for a display bar is activated and submerged with adequate depth in the molten steel. A diameter difference of the rod between the immersed in the casting powder and the steel melt in the areas is detected. After a predetermined time, the rod is pulled out. In this case, the diameter of the material adhering to the rod is detected by means of laser beams.

The document US 4,647,854 relates to a device for measuring the level of molten metal in an oscillating mold of a continuous casting plant during operation with an eddy current measuring device.
The oscillation of the mold is extracted from the output signal of the distance measurement while compensating and controlling the measurement sensitivity of the distance measuring device to keep constant the amount of amplitude of the oscillation signal component, thereby linearizing the surface level of the melt.

The document JP 6 000 601 A describes a device for measuring the level of liquid metal in a continuous casting mold. Here is the holder of the level sensor firmly connected to the mold or the water tank.

Based on the aforementioned prior art, the present invention seeks to provide a sensor for detecting the level of the molten metal level in a mold of a continuous casting and a method for its operation, which follows the movements of the mold with as precise and play-free guidance of the sensor in the event of a fault, it responds almost instantaneously.

The solution of this problem is inventively achieved in a sensor referred to in the preamble of claim 1 by the characterizing features of the device claim 1 and the method claim 4.
In subclaims device and method are further configured.

According to the invention, the sensor for detecting the filling level of the liquid metal in the mold of the continuous casting is characterized by a pivot drive for a pivotable about the axis x-x lever arm, at the free end of the sensor is fixed by a holder.

The sensor has in one embodiment alternatively pneumatic or hydraulic rotary actuators, for example. Rotary piston or electromechanical or magnetic part-turn actuators to its at least rotary drive.

In a further embodiment of the sensor, the releasable clamping device for attaching the manipulator can be provided on at least one broad side or narrow side wall of the mold or its water boxes or on the peripheral frame.

According to the invention, the sensor is pivoted by the manipulator before the casting operation by a pivoting movement of its lever arm about the axis of the pivot drive from a neutral position above the Kokillengießraumes in the active measurement position within the mold.

The method according to the invention further provides that the sensor in predetermined movements for detecting the filling level and position of the metal mirror in the mold by means of pivoting movements about the axis of the lever arm and, if necessary, by means of linear extension or shortening movement and / or possibly by rotation about the Vertical axis of the rotary actuator in accordance with control signals of a programmable signal transmitter is performed.

And finally, the method according to the invention provides that the sensor is turned out on receipt of a fault signal by swinging the lever arm from the Kokillengießraum in a neutral position.

The operating method for the sensor of the aforementioned type provides according to the invention that its movements are performed manually or automatically.

Further details, features and advantages of the invention will become apparent from the following explanation of an embodiment schematically illustrated in the drawings.

Fig. 1

in perspektivischer Ansicht einen von einem Manipulator in den Gießraum einer Kokille einschwenkbaren Sensor;

Fig. 2

den Manipulator mit angeordnetem Sensor in perspektivischer Schnittdarstellung.

Show it:

Fig. 1

in perspective view of a swivelable by a manipulator in the casting room of a mold sensor;

Fig. 2

the manipulator with arranged sensor in a perspective sectional view.

The manipulator shown in Figures 1 and 2 has the task to guide a sensor 1 for detecting the level of liquid metal level in a mold 2 of a continuous casting. The sensor is used for the mold level control. The manipulator is fixed by means of a releasable clamping on the mold 2 and its water boxes 12, so that the sensor 1 is coupled to the movements of the mold 2. The clamping consists in the illustrated embodiment of a arranged on guide rails 14 mounting plate 3 with a tilt and screw clamp 13th

The manipulator comprises a pivot drive 4 which can be connected to the fastening plate 3 and has a lever arm 5 which can be driven rotatably about the longitudinal axis xx and at whose free end 7 the sensor 1 can be fastened by means of a preferably right-hand holding rod 8.
As a result, a compact design is achieved because the sensor 1 is directly coupled to the mold 2, whereby an influence of signals is avoided.

The manipulator with pneumatic or hydraulic swivel assembly 6 is designed as a rotary piston 9 or equipped with electromechanical or magnetic rotary actuators. The manipulator is optionally rotatable about its vertical axis z-z, for which purpose an additional horizontal rotary piston 9 'can be arranged in the pivot drive 4, as shown in FIG.

With the numeral 10, a floating layer of slag or casting powder is referred to within the mold 2, which is required as a lubricant to achieve optimum sliding between the molten steel and the wall of the mold 2.

The operation of the manipulator or its movements can be performed manually or automatically.

In the predetermined position of the manipulator according to Fig. 1, the sensor 1 is just before casting start by a pivoting movement of the pivot drive 4 by the lever arm 5 about the axis xx from a neutral position above the mold 2 in a measuring position just above the bath level 10 corresponding to the level height the melt has been swung in the mold.

A particular advantage of the operating method is given by the fact that the manipulator turns out the sensor 1 from the mold 2 in a neutral position upon receipt of a disturbance signal by swinging the lever arm 5, to prevent endangerment of the sensor for detecting the level height.

The manipulator may additionally be designed such that the sensor 1 fastened in the holder 8 can be moved or adjusted in the direction of the xx axis of the lever arm 5 by means of linear extension or shortening movements, see arrow 11. Also possible is an embodiment of the manipulator to the effect that the pivot drive 4 leads out by rotation about its vertical axis out of the region of the Kokillengießraumes in a top neutral position unscrewed sensor 1. For this purpose, as shown in Figure 2, the horizontally disposed rotary piston 9 'are acted upon by hydraulic media.

List of reference numbers

1. 1st sensor
2. 2. Mold / Kokillengießraum
3. 3. mounting plate
4. 4. rotary actuator
5. 5. lever arm
6. 6. Swivel arrangement
7. 7. free end
8. 8. Holder
9. 9. Rotary piston
10. 10. Floating layer slag
11. 11. arrow
12. 12. Water tank
13. 13. Clamping device
14. 14. Guide rails

Claims (7)

1. Sensor (1, 4, 5) for detecting the filling state height of liquid metal in the mould (2) of a continuous casting plant, with a manipulator for guiding the sensor, wherein the manipulator together with the sensor (1) arranged thereat is fastened, with use of a detachable connection, particularly by means of clamping, on or at the mould (2) or at the water tank (12) thereof and the sensor (1) is thus coupled with the movements of the mould (2), characterised by a pivot drive (4) for a lever arm (5), which is pivotable about the axis (x-x) and at the free end (7) of which the sensor (1) is fastened by means of a mount (8).
2. Sensor (1, 4, 5) according to claim 1, characterised by pneumatic or hydraulic pivot drives (4), for example rotary pistons (9), or electromechanical or magnetic pivot drives for at least rotational drive (6) thereof.
3. Sensor (1, 4, 5) according to claim 1 or 2, characterised by a releasable clamping device (13) for fastening thereof to at least one of the wide-side or narrow-side walls of the mould (2) or to the water tank or circumferential frame thereof.
4. Method of operating the sensor (1, 4, 5) according to claims 1 to 3, characterised in that the sensor (1, 4, 5) before start of casting is pivoted by a pivot movement of the lever arm (5) about the axis (x-x) of the pivot drive (4) out of a neutral position above the mould casting space into the active measuring position within the mould.
5. Method according to claim 4, characterised in that the sensor (1, 4, 5) is guided in predeterminable movements for detection of the filling state height and the position of the metal surface in the mould (2) by means of pivot movements about the axis (x-x) of the lever arm (5) as well as if required by means of linear extension or reduction movements (arrow 11) and/or in a given case by rotation about the pivot axis (z-z) of the pivot drive (4) in accordance with control signals of a programmable signal transmitter.
6. Method according to one or more of claims 4 and 5, characterised in that the sensor (1, 4, 5) on input of a fault signal is rotated out into a neutral position by pivotation of the lever arm (5) out of the mould casting space (2).
7. Method according to one or more of claims 4 to 6, characterised in that the movements of the sensor (1, 4, 5) are executed manually or automatically.

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