METALLURGICAL VESSEL AND ADJUSTMENT DEVICE

Abstract: A metallurgical vessel (5) such as a tundish fitted with a slide gate at its underside for discharging its contents has the slide gate controlled by a drive that can be removed to another vessel when required. The drive comprises a hydraulic cylinder (1) with a drive rod (2,3) projecting from it and carrying a coupling releasably engageable with the slide gate. The cylinder (1) and drive rod (2,3) are clamped non-rotatably in use but when attaching or removing the drive they can be rotated about a common longitudinal axes to alternative angular positions in which the slide gate is coupled or uncoupled thereto. Changeover of the drive can be made quickly thereby. A double-ended drive constructed in this manner can be used with vessels having two controllable outflow devices and provides for an equally quick changeover.

Description: The invention relates to a metallurgical vessel having on its underside an adjustable outflow device, for example a tundish, for a continuous casting machine with a slide gate, which outflow device is connected to a drive device via a coupling and a drive rod in the driving direction. The invention also concerns a removable adjustment device comprising a drive means, a drive rod and a coupling, which may be used in vessels provided with an adjustable outflow device and which are intended to be mobile. Metallurgical vessels with an adjustable outflow device on their underside are employed frequently in the steel industry (see, e.g. GB l477l73). An example is the tundish of a continuous casting machine, from which a nozzle projects into a mould. The outflow through this nozzle is controlled by a slide gate. Such a tundish is designed to be mobile as it must be possible for casting to continue with a replacement tundish when for example the tundish has to be repaired. The frequency with which a tundish has to be replaced depends on the casting cycle. Usually three to four ladles of steel to be cast are emptied into the tundish, and after casting is completed and the tundish has had any remaining steel and slag emptied out of it, it is replaced. Sometimes the tundish is replaced after one charge, that is after the contents of one ladle have been cast. The quality of the lining and the outflow openings of the tundish used for casting are then checked. For these methods of operation it is necessary to have a number of tundishes in circulation, with it being necessary for them to be replaced quickly because of the need to maintain the required production capacity of the casting machine. The slide gate fitted on the underside of the tundish is connected via a drive rod in the driving direction to a drive device, such as a hydraulic cylinder. Tundishes which include a hydraulic cylinder can be replaced rapidly as only the hydraulic supply and discharge lines have to be disconnected or connected. This does, however, have the disadvantage that oil from the hydraulic system can get onto the casting platform, which increases the risk of fire. In addition, the hydraulic system must be vented at regular intervals, and dirt can enter the system, which causes oil leaks. In US 4042207 a casting ladle or tundish is disclosed with a slide gate permanently secured to its underside but a removable hydraulic cylinder drive for adjusting the slide gate. In this way the disadvantages of having to disconnect the hydraulic lines are avoided, but the manner of attachment of the slide gate adjustment device is not suited for fast and secure operation. The hydraulic cylinder is hooked onto lugs projecting from the slide gate and it is then necessary to manipulate the piston rod projecting from it (it is suggested that both axial and rotational movements of the rod may be required) in order to couple the rod drivingly with a moveable part of the slide gate. Even after this series of operations the adjustment device is not positively secured to the tundish or the slide gate; it relies on its own weight providing a stabilising force to hold it in position. In one of its aspects, the invention provides a vessel having a holder fixed to its underside which may be swung open to receive a removable drive device which comprises a drive rod rotatable about is longitudinal axis, by means of which the coupling connected to a projecting end of the drive rod can be released and fixed. In another of its aspects, the invention provides the advantage of such an arrangement, that the conversion of the drive from one tundish to the next can be carried out very quickly, is particularly important in the cases of so-called twin casting. In twin casting two nozzles are present in one mould, from which steel is brought from the tundish into the mould. For each nozzle a slide gate with drive is provided, by means of which the steel stream can be controlled. The number of drives to be replaced and the time needed for this is double that of normal casting. The assembly of the present invention and associated dismantling technique is particularly valuable in twin casting for maintaining a high production capacity of the continuous casting machine. Preferably the drive device is of a double-headed design with two drive rods and two couplings, each of which is connected to one outflow device. An important advantage is that the assembly and dismantling time is not very different from that in normal casting, as the number of drives to be changed is equal to the number of drives in normal casting. Further, the double-headed design of drive device makes effective use of the limited space under the tundish, where there is not room for extra drives. It is preferable for the two drive rods to be coupled in their direction of rotation so that the couplings of both drive rods can be loosened or tightened at the same time. It is further preferable for the drive rod to have a pawl or other projection by means of which the drive rod can be rotated, and a guide to engage the pawl and thereby block the rotary movement of the drive rod. By this means the coupling which turns with the drive rod is quickly interlocked. In a preferred embodiment the drive device is in the form of a cylinder, and a driven element fitting in the cylinder has a fixed connection to the drive rod. Consequently the drive rod does not have to be loosened from the driven element, and it is not necessary to use another construction where the drive rod can rotate without the drive device having to rotate at the same time. In this preferred embodiment the driven element is connected non-rotatably to the drive rod and the drive rod can be rotated by turning the driven element in the cylinder. In another preferred feature the inner wall of the cylinder has a key or key-way running in the longitudinal direction, and the driven element has a recess or protruberance, respectively, mating therewith. These mating elements then act as a positive connection between the cylinder and the driven element. Thus, after positioning the cylinder in the holder, the cylinder can be rotated, for example by a handle fixed to it, as a result of which the drive rod is also rotated and the coupling is interlocked. The leakage which usually occurs with a hydraulic cylinder having a key or key-way is in this case an advantage as the leakage oil carries away excess heat at the underside of the tundish. It is preferable for the holder to be operable by having a movable part hinged on one side to a fixed part of the holder and fixed by a clamp on the other side of the fixed part of the holder, which clamp is connected for swivelling on the fixed part of the holder. By this means the coupling of the slide gate drive for a new tundish can be caried out by means of four operations, namely: a. hanging the drive in the holder b. driving out the piston until the portion of the coupling connected to the drive rod engages the portion of the coupling which is connected with the outflow device. c. turning the drive until the coupling is secured. d. interlocking the coupling by securing the clamp. A preferred embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawings in which Figure l shows a drive device, the drive rods mating with it and one of the associated couplings which is secured to a slide gate. Figure 2 is a cross-section through the drive device on line B-B in Figure l. Figure 3 shows the fixing of the coupling to the slide gate in a cross-section on line A-A in Figure l, in the unsecured state. Figure l shows as the drive device a hydraulic cylinder l which is of a double-sided design with two opposite drive rods 2 and 3. The hydraulic cylinder l can be suspended from a holder 4 which is fixed to the underside of a tundish 5. One end of drive rod 2 is fixed to the hydraulic cylinder l by piston 6, and the other end to coupling 7. By turning coupling 7 it can be secured. A similar design is provided for drive rod 3. In practice, mounting of the adjustment device is carried out as follows: Holder 4 (Fig. 2) consists of a fixed part 4 i and a movable part 4 ii . The movable part 4 ii is attached on one side with a hinge 8 to the fixed part 4 i . On the other side both parts are coupled together with a clamp 9 which can be swung aside. After undoing and swinging aside clamp 9, the movable part 4 ii of holder 4 is swung open and the hydraulic cylinder l of the adjustment device is hung in holder 4. When positioning the hydraulic cylinder l, pistons 6 and l4 are retracted. After suspending the hydraulic cylinder l in the holder 4, the pistons 6 and l4 are extended until coupling 7 engages slot l0 (see Fig. 3) of the slide gate (not shown). The same applies for the unillustrated coupling and slot at the end of the drive rod 3. A handle ll attached to hydraulic cylinder enables cylinder l to be rotated in holder 4. The cylinder l has a key l2 fixed to its inside face, and pistons 6 and l4 each have a key-way l3 into which the key fits. Because of the connection so formed, the rotation of cylinder l is transmitted to drive rod 2 and coupling 7 to secure coupling 7 secured in slot l0, and simultaneously the coupling which is connected to drive rod 3 is secured in its associated slot. The drive rods 2 and 3 are thereby axially coupled to their slide gates. Then the movable part 4 ii of holder 4 is gripped against the fixed part 4 i by tightening clamp 9. As a result coupling 7 is interlocked in slot l0, and likewise for the coupling connected to drive rod 3, until they are released again by reversing the procedure. The device is now ready for simultaneously operating the slide gates coupled to the drive rods 2 and 3. This situation is shown in Figure l.

Claims: 1. Metallurgical vessel (5) having at its underside an adjustable outflow device, for example a tundish for a continuous casting machine with a slide gate, the outflow device being connected to a removable drive deviced (l) through a coupling (7) at one end of a drive rod (2 or 3), characterised in that the drive device (l) is mounted in a holder (4) which can be swung open and which is fixed to the vessel underside, that the drive rod (2 or 3) can be rotated about its longitudinal axis, by means of which the coupling (7) which is connected to one end of the drive rod can be released and engaged. 2. Vessel in accordance with claim l, where two adjustable outflow mechanisms are present, characterised in that the drive device (l) is of a double-sided design with two drive rods (2 and 3) and two couplings (7) which are connected to respective outflow devices. 3. Vessel in accordance with claim 2, characterised in that the drive rods (2 and 3) are coupled in their direction of rotation. 4. Vessel in accordance with any one of claims l to 3, characterised in that the drive rod (2 or 3) has a pawl or other rotary engagement element by means of which the drive rod can be rotated, with it being possible to fit this pawl into a guide by means of which the direction of rotation of the drive rod is blocked 5. Vessel in accordance with any one of claims l to 4, characterised in that the drive device is of the form of a cylinder (l), with a driven element (6 or l4) fitting in the cylinder having a fixed connection with the drive rod (2 or 3). 6. Device in accordance with claims 4 and 5, characterised in that the inner wall of the cylinder (l) has a key or a key-way (l2) running in the longitudinal direction, and the driven element has a recess or a mating protruberance (l3) engaging therewith, whereby the driven element and the key (way) act as a pawl and guide. 7. Vessel in accordance with any one of the preceding claims, characterised in that the holder comprises a movable part (4ii)hinged on one side to a fixed part (4i) of the holder, and the movable part is clamped on the other side to a fixed part of the holder by a clamp (9) having a swivel connection (8) on the other side to the fixed part of the holder. 8. A removable adjustment device for use in controlling an outflow device of the underside of a metallurgical vessel and comprising a drive device (l) for connection to the outflow device through a coupling (7) at one end of a drive rod (2 or 3), characterised in that the coupling can be released or engaged by turning the drive rod about its longitudinal axis. 9. Adjustment device in accordance with claim 8, characterised in that the drive device (l) is of a double-sided design with two drive rods (2 and 3) and two couplings (7) which can be connected to respective outflow devices. l0. Adjustment device in accordance with claim 9, characterised in that the two drive rods (2 and 3) are coupled in their direction of rotation. 11. Adjustment device in accordance with any one of claims 8 to l0, characterised in that the drive rod has a pawl or other rotary engagement element by means of which the drive rod can be rotated, with it being possible to fit this pawl into a guide which blocks the movement of the drive rod. 12. Adjustment device in accordance with any one of claims 8 to ll, characterised in that the drive device (l) is of the form of a cylinder, with a driven element (6 or l4) fitting in the cylinder having a fixed connection with the drive rod (2 or 3). 13. Adjustment device in accordance with claims ll and l2, characterised in that the inner wall of the cylinder (l) has a key or a key-way (l2) running in the longitudinal direction, and the driven element a mating recess or a protruberance (l3) engaging therewith with the driven element and the key (way) acting as pawl and guide.

Inventors: DE WAAL MALEFIJT, JACOBUS A., HARINGHUIZEN, CORNELIS
Applicants: HOOGOVENS GROEP B.V.
Application year: 1986
Main classification: B22D41
IPC codes: B22D41