KR20120132637A - Device and method for closing an outflow opening of a metallurgical vessel - Google Patents

Abstract

The present invention relates to an apparatus (200) and a method for closing the outlet (120) of a metallurgical vessel (110). The closing device includes a stopper rod 205 disposed to close the outlet 120 at the top of the outlet 120 in the container, and a stopper rod mechanism 210 for raising and lowering the stopper rod 205. And a sensor 220 for detecting vibration of the stopper rod 205 or the stopper rod mechanism 210. In order to detect the timing of closing the outlet of the metallurgical vessel as timely as possible and to achieve an optimum separation between the melt and the slag, the closing device 200 is provided at the stopper rod 205, or at the stopper rod mechanism 210. And a control device 230 for actuating the closing unit for the outlet 120 of the container in accordance with each vibration detected by the sensor 220.

Description

DEVICE AND METHOD FOR CLOSING AN OUTFLOW OPENING OF A METALLURGICAL VESSEL}

The present invention relates to an apparatus and a method for closing an outlet in a metallurgical vessel.

In a continuous casting system, the injection process of molten steel takes place through an injection ladle and a tundish (distribution chute) into a vibratory permanent mold with a strand guide system disposed behind it. The maximum emptying of the tundish / dispensing chute as desired is initiated by a sequence that is manually or automatically controlled under conditions that take into account the current casting speed, current tundish weight and experience of the casting expert. In order to ensure the optimum quality of the slab, it must be avoided that the slag floating on the melt is subsequently introduced into the continuous casting mold. Basically, slag reaching within the continuous casting mold will force the casting process to stop because the slag content renders the casting material useless. In addition, checking the presence of defect locations due to slag inclusions in the treated casting material raises the price of the product. To avoid this, various approaches / methods have been developed to measure when slag mixes with the melt during the injection process. It has been found that when the melt level falls in the tundish, a vortex is formed at the outlet (Vortex Effect). Based on the vortex effect, slag located on the surface of the molten bath is pulled together into the outflowing melt and into the injection flow of the melt.

From EP 0 172 394 a control and measurement method is known which prevents the penetration of slag into a continuous casting mold and thus into the casting material. The European publication discloses a continuous measurement of the weight of a storage container comprising a melt and a continuous measurement of the surface height of the melt in the storage container, which is time parallel. The presence or absence of slag is evaluated from the variation in the specific weight of the melt.

From WO 2005-062846 it is known how the vortex effect is detected via microwave measurement just above the outlet and then the closure of the outlet is activated.

From WO 90-13380, a method and apparatus are known in which vortex effects are detected through vibration measurements in the outlet pipe of a vessel. The corresponding signal is then supplied to the control device, which causes the closing of the outlet through insertion of the slide into the outlet pipe in response to the signal. Since the vibration sensor is mounted on the lower linkage of the detection device, the vortex effect is undesirably measured only when the vortex effect is formed in the outlet tube and then the vibration is transmitted to the detection device.

It is an object of the present invention, on the basis of the above-mentioned prior art, in a known device or known method for closing the outlet of a metallurgical vessel, the time of occurrence of the vortex effect is detected immediately upon occurrence, It is an improvement of the device or method in such a way that closure occurs in a timely and instant manner.

This object is achieved with the object of claim 1. The object includes a stopper rod disposed to close the outlet at the top of the outlet in the vessel, a stopper rod mechanism for raising and lowering the stopper rod, and a stopper rod caused by flowing melt from the vessel through the outlet Or a sensor for detecting a vibration of the stopper rod mechanism and a control device for operating the closing unit for the outlet of the container according to each degree of vibration detected by the sensor in the stopper rod or stopper rod mechanism.

Vortex is a synonym for vortex. In rheology, fluid flow fluctuations are often referred to as vortices. As fluid enters the outlet tube from the vessel, a vortex is formed because a sufficiently large velocity gradient occurs inside the fluid. In other words, part of the liquid flows much faster than the rest.

The stopper rod is placed in the melt just above and at the center of the outlet of the metallurgical vessel and the stopper rod mechanism is connected to the stopper rod, thereby providing the possibility of instant vibration absorption at a very suitable point in the center of the vortex. Sensors disposed in the stopper rod or stopper rod mechanism detect vibration as the primary signal and transmit the primary signal to the control device. As soon as the vortex processing situation occurs in the vessel, the sensor immediately transmits the vibration of the stopper rod or stopper rod mechanism directly to the control device in the form of an electrical signal, which immediately leads to the closing of the outlet of the metallurgical vessel. With the vortex effect being detected at an earlier point in time than in the prior art and the closing of the resulting outlet at an earlier point in time than in the prior art, in the case of the present invention, optimal steel production with low losses is ensured. Optimal steel yield is ensured when the maximum proportion of metal melt flows into the continuous casting mold and the slag ratio is equal to zero. In addition, timely closure of the tundish / dispensing chute, which is reliable, reproducible and targeted, is also provided by the arrangement. A further advantage is the improved purity of the final slab, that is to say there is no slag in the steel flow to the permanent mold.

According to the first embodiment the closing unit for the outlet is formed as a slider disposed under the outlet or as a stopper rod. The two closing processes of the outlet using the stopper rod or the slider under the outlet allow the outflow of slag contained in the melt. The slider can also be formed as an emergency slider, that is, the outlet can be closed even when the stopper rod does not close the outlet sufficiently. This may arise, for example, due to technical defects.

Sensors that can be formed as electrical vibration sensors, acceleration sensors, acoustic sensors, strain gage strips, force sensors, pressure sensors, or position sensors can sufficiently and immediately detect vibration frequencies in the stopper rod or stopper rod mechanism and detect the detected vibrations. It is transmitted to the control device as an electrical signal.

The above object is also achieved by the method as claimed in the independent claim 4 relating to the method. The advantages of the solution according to the method correspond to the advantages mentioned above in connection with the apparatus.

Further preferred embodiments of the advantages and methods of the invention are set out in the dependent claims.

According to the present invention, on the basis of the above-mentioned prior art, in the known apparatus or known method for closing the outlet of a metallurgical vessel, the time of occurrence of the vortex effect is detected immediately upon occurrence, and the closure of the vessel In a manner that is timely and immediate, it is provided to improve the apparatus or method.

One diagram is attached to this specification. therefore
1 is a schematic diagram showing an arrangement of the apparatus.

The apparatus according to the invention and the method according to the invention are described in detail with reference to FIG. 1 below.

A metallurgical vessel 110 is shown in FIG. 1, which receives the melt 140 from the ladle 100 and then discharges the melt through the outlet 120 into the vibratory permanent mold 130. do. The strand guides that are subsequently connected are not shown herein. A stopper rod 205 is disposed just above and at the center of the outlet 120, which stopper rod is connected to the stopper rod mechanism 210. The stopper rod 205 or the stopper rod mechanism 210 is equipped with a sensor 220, which signals the vibration of the stopper rod 205 or the stopper rod mechanism 210 caused by the vortex formation in the melt 140. As a control to the control device 230 as. Under the outlet 120, a slider 300, which can also be used as an emergency slider, is disposed. The outlet 120 can thus be closed by the stopper rod 205 or by the slider 300.

The vortex effect that occurs upon exiting the melt 140 from the metallurgical vessel 110 generates vibrations in the melt 140. Vibrations occurring in the melt 140 are transmitted to the stopper rod 205 located in the melt 140 and thus to the stopper rod mechanism 210. Because the stopper rod 205 is disposed directly above and at the center of the outlet 120, an immediate and direct transmission of vibration as a primary signal is provided to the stopper rod 205 and the stopper rod mechanism 210. The vibration is detected by the sensor 220 disposed on the stopper rod 205 or the stopper rod mechanism 210 and transmitted as a signal to the control device 230. The control device 230 compares the signal with a predetermined threshold. If the actual amplitude and / or frequency of the vibrations represented by the signal exceeds a predetermined threshold, the control device generates an output signal that activates the closure. Accordingly, the stopper rod 205 or the slider 300 below the outlet 120 is activated to cause the outlet 120 to be closed. Since there is a risk of mixing the slag and the melt from the time of the vortex effect, the stopper rod 205 should be immediately lowered in a timely manner as desired, or the slider 300 at the bottom of the outlet 120 may be lowered. The steel flow must be shut off quickly and timely as desired. In the case of the present invention, a time point for the closure of the outlet is required in such a way that optimal separation between the melt and the slag is achieved. The exact time point is determined through the vortex effect that always occurs when the metallurgical vessel 110 has to be emptied at the end of the casting, or at the exchange of the vessel 110.

100: ladle
110: metallurgy container
120: outlet
130: permanent mold
140: melt
200: closure device
205: stopper rod
210: stopper loading mechanism
220: Sensor
230: control unit
300: slider

Claims (5)

In the device 200 for closing the outlet 120 of the metallurgical vessel 110,
A stopper rod 205 disposed to close the outlet 120 on the outlet 120 in the container;
A stopper rod mechanism 210 for raising and lowering the stopper rod 205,
A sensor 220 for detecting vibration of the stopper rod 205 or the stopper rod mechanism 210 caused by flowing the melt 140 out of the vessel through the outlet 120;
Control device 230 for operating the closing unit for the outlet 120 of the container according to each degree of vibration detected by the sensor 220 in the stopper rod 205 or the stopper rod mechanism 210. Closing device (200). The closing device according to claim 1, wherein the closing unit for the outlet port 120 is formed as a slider 300 disposed below the outlet port 120, or as a stopper rod 205. 200). The closing device (200) of claim 1, wherein the sensor (220) can be formed as an electrical vibration sensor, an acceleration sensor, an acoustic sensor, a strain gauge strip, a force sensor, a pressure sensor, or a position sensor. As a method for closing the outlet 120 of the metallurgical vessel 110,
Detecting vibrations in the melt 140 in the metallurgical vessel 110 using the sensor 220 based on vortex formation when the melt 140 flows out of the vessel,
In the closing method comprising operating the closing unit for the outlet opening of the container according to each degree of vibration detected by the sensor 220,
Vibration in the melt 140 is transmitted to the stopper rod 205 and the stopper rod mechanism 210 protruding into the melt 140, and the sensor at the stopper rod 205 or the stopper rod mechanism 210. Closure method, characterized in that detected by (220). 5. The method according to claim 4, wherein said value, which is a value of amplitude and / or frequency of a signal generated and reproduced by said sensor 220 and reproducing the detected vibration, is greater than or equal to a predetermined threshold value. Causing the closure method.

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