GB2156253A

GB2156253A - Horizontal continuous casting apparatus

Info

Publication number: GB2156253A
Application number: GB08508476A
Authority: GB
Inventors: Guillermo Holtschneider
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1984-03-30
Filing date: 1985-04-01
Publication date: 1985-10-09
Also published as: CA1242067A; JPS61129258A; FR2561958B1; FR2561958A1; IT1183519B; IT8520143A0; DE3411769A1; DE3411769C2; JPH0133264B2; GB8508476D0; GB2156253B

Abstract

A multi-strand horizontal continuous casting apparatus is provided with a supply vessel (5) and several horizontal continuous casting moulds (6). The supply vessel (5) is separable from the horizontal continuous casting moulds (6), and sealable relative thereto. The supply vessel (5) is provided with a respective orifice for supplying molten metal to each of the moulds (6). Each orifice is defined by a perforated brick (13) having an inserted nozzle brick (14). In order to take up any misalignment between the axis (12) of an orifice and the axis (11) of the associated mould (6), each mould is provided with an adjustable connection (15). Each connection (15) is adjustable relative to the axis (11), and sealingly engages the end portion (14a) of the respective nozzle brick (14), whereby simple and rapid exchange of one or more of the moulds (6) is possible. <IMAGE>

Description

SPECIFICATION Horizontal Continuous Casting Device This invention relates to apparatus for the horizontal continuous casting of metal such as steel.

Horizontal continuous casting apparatus generally comprises a supply vessel which is arranged to receive molten metal from a casting ladle. The supply vessel is connected, in a separable and optionally sealable manner, to one or more horizontal continuous casting moulds. A respective extraction machine is aligned with each of the horizontal continuous casting moulds for removing the respective strands of solidified metal. Horizontal continuous casting apparatus of this type allows casting to be carried out continuously without interruptions. Maximum exploitation of the apparatus and of its service life are desirable, and to this end it is known to provide each mould with a detachable connection to the supply vessel. The detachable connections prevent heat loss, and enable the discharge of metal from the supply vessel to be interrupted, for example for maintenance work.

An interruption in the casting process is generally accompanied by a casting break in the cast strand, so the remainder of the billet in the horizontal continuous casting mould has to be removed after solidifying. It is usually necessary to discard the remaining content of the supply vessel when the casting process is interrupted. After the supply vessel has been separated from the horizontal continuous casting mould, it can be tilted, cleaned and inspected. However, known types of apparatus do not solve the problem as to how the supply vessel and the horizontal continuous casting mould(s) can be reconnected in alignment after maintenance work.

In the past, the fact that the supply vessel, horizontal continuous casting mould(s) and extraction machine(s) were not aligned after a certain number of charges (often after being heated for the first casting) was ignored. Typically, the misalignment between a horizontal continuous casting mould and the supply vessel can reach values of, for example, 10 millimetres, depending on whether the horizontal continuous casting apparatus delivers one or more strands.

The aim of the invention is to provide a horizontal continuous casting apparatus which does not suffer from errors of alignment between its supply vessel and its horizontal continuous casting mould(s).

The present invention provides apparatus for the horizontal continuous casting of metal, the apparatus comprising a supply vessel for containing molten metal, at least one horizontal continuous casting mould whose central longitudinal axis defines a casting axis, the supply vessel being provided with a respective orifice for supplying molten metal to the or each mould, wherein the or each mould is detachably connected to the supply vessel in alignment with the respective orifice by an adjustable connection, and wherein the or each orifice is defined by a respective perforated brick having an inserted nozzle brick, the or each adjustable connection being adjustable relative to the casting axis of the respective mould, and sealingly engaging the end portion of the respective nozzle brick.

The provision of adjustable connection(s) of this type permits any misalignment between the axes of the supply vessel and the horizontal continuous casting mould(s) to be taken up. As the or each adjustable connection simultaneously acts as a seal, any such misalignment can be taken up, in the interior of the adjustable connection, in such a way that a slight deflection of the liquid metal stream occurs, but has no detrimental effects.

Advantageously, the or each adjustable connection lies on one side of the supply vessel. In this arrangement, the or each horizontal continuous casting mould and/orthe supply vessel can be exchanged simply and rapidly, either laterally or upwardly in the horizontal continuous casting apparatus.

In a preferred embodiment, the or each adjustable connection can be provided on the underside of the supply vessel inside an angular casting metal guide means which is connected directly to the or each horizontal continuous casting mould. Consequently, the or each horizontal continuous casting mould can be dismounted and re-mounted in a generally vertical direction. More specifically, if the supply vessel is to remain unchanged in its position, the mould(s) can be moved both vertically and slightly to one side, and dismounting work can then take place unaffected by the casting ladle located above the supply vessel during the casting process.

Advantageously, the or each adjustable connection is provided with at least one concentrically arranged sealing ring, the sealing ring(s) defining a bearing surface which engayes with the end portion of the nozzle brick. The concentric sealing ring(s) increase the sealing action on the end face of the nozzle brick. Consequently, the need for a greater sealing action in the case of large axial differences between the supply vessel and the mould(s) is met.

The desired sealing action can be improved if the or each adjustable connection includes a spacer clamped against the free end of the associated nozzle brick, and if either the end portion of that nozzle brick or that spacer, which complement the associated bearing surface, is three-dimensionally oval, for example spherical, in shape.

Where the or each adjustable connection is provided on the underside of the supply vessel, greater movability when dismounting the horizontal continuous casting mould(s), which need not be removed separately from the other components, can be achieved by providing a cardan-mounted runner in the vertical arm of the angular cast metal guide means, the runner being connected to the supply vessel in an air-tight manner. This division into different structural groups allows the horizontal continuous casting mould(s), together with other components, to be dismounted, for example driven out, downwards or rearwards with respect to the horizontal continuous casting apparatus.

In order to take account of the metallurgical requirements during casting operations, the runner preferably is sealed from the external atmosphere in the angular cast metal guide means.

Advantageously, the vertical arm of the angular cast metal guide means is of variable height.

Preferably, the vertical arm of the angular cast metal guide means includes a telescopic section, whereby the height of the vertical arm can be varied in dependence upon the required ferrostatic pressure.

In a preferred embodiment, the supply vessel and/orthe angular cast metal guide means is provided with a base tap hole which can be sealed by means of a sealing member. Such a tap hole is useful in an emergency, for example during interruption of casting onto an individual horizontal continuous casting mould of a multiple strand horizontal continuous casting apparatus.

Three forms of horizontal continuous casting apparatus, each of which is constructed in accordance with the invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. lisa plan view of part of the first form of horizontal continuous casting apparatus; Fig. 2 is a cross-section taken on the line 1I--II of Fig. 1; Fig. 3 is an enlarged part-sectional elevation of the supply vessel and horizontal continuous casting mould of the first form of apparatus; Fig. 4 is a part-sectional elevation of the supply vessel and horizontal continuous casting mould of the second form of apparatus; and Fig. 5 is a part-sectional elevation of the supply vessel and horizontal continuous casting mould of the third form of apparatus.

Referring to the drawings, Fig. 1 shows a continuous casting appartus which is designed to produce four cast strands of metal, only two of which (1 and 2) can be seen. The other two strands are positioned symmetrically to the strands 1 and 2 on the other side of the axis 3 of symmetry. In use, liquid metal (for example liquid steel) is passed from a casting ladle 4 into a supply vessel 5. In some cases, however, the casting ladle 4 can also act as a supply vessel (for example in a single strand apparatus), in which case a separate supply vessel is not required.

Four horizontal continuous casting moulds 6 are connected to the supply vessel 5. The supply vessel Scan be driven into, and out of, the illustrated operating position along a track 7. Alternatively, the supply vessel 5 can be positioned using a crane. A respective extraction machine 8 is located downstream of each of the horizontal continuous casting moulds 6 in the direction of travel of the strands. Liquid metal flows from the casting ladle 4 into the supply vessel 5 via a ladle inlet 9. The supply vessel 5 is provided with a base tap hole 10, which is offset from the ladle inlet 9. Liquid metal flows from the supply vessel 5 to the moulds 6 via lateral orifices, each of which is constituted by a perforated refractory brick 13 and an inserted refractory nozzle brick 14.

Each mould 6 is accurately aligned with the respective casting axis 11, for example, by means of laser optics, during construction of the apparatus.

Each mould 6 is also aligned with the axis 12 of the associated nozzle brick 14 during construction of the apparatus. The supply vessel 5 tends to stretch and distort after several charges, or even after the first heating process, resulting in misalignments between the axes 11 and the axes 12. A respective adjustable connection 15 between the supply vessel 5 and each of the moulds 6, is provided to compensate for these misalignments. In so doing, each connection 15 provides a seal on the end portion 14a of the associated nozzle brick 14. A sealing member 16, which stops the fiow of liquid metal into the associated mould 6, is located in the region of each nozzle brick 14.

The adjustable connections 15 are arranged on the side 8a of the supply vessel 5 facing the extraction machines 8 (see Fig. 2). Alternatively, the adjustable connections 15 could be located on the underside 5a of the supply vessel 5 (see Figs. and 5).

In use, liquid metal passes from the casting ladle 4 into the supply vessel 5, via an open slide valve 17 and a shadow tube 18, the slide valve 17 acting as a flow control member. On completion of a casting operation, or in an emergency, the liquid metal can be tapped from the supply vessel 5 through the base tap hole 10, when its base seal 10a is open, into an emergency ladle 19.

Each connection 15, which is adjustable relative to the associated casting axis 11, is also provided with concentric sealing rings 20 and 21 (see Fig. 3) for sealing against the end portion 14a of the associated nozzle brick 14. The provision of the two sealing rings 20 and 21 meets the need for a good sealing action in cases where there is a relatively large axial distance between the supply vessel 5 and the associated mould 6. The sealing rings 20 and 21 define a bearing surface 26, which may be spherical.

Each end portion 14a is constituted buy a separate seal 22 made of refractory material. A spacer 23 is positioned against the end face of the seal 22 and the sealing ring 20 of each connection 15. The sealing rings 20 and 21, the seal 22 and the spacer 23 of each connection 15 are held together by meansofscrew-threaded members 24. Each mould 6 is clamped and sealed against the supply vessel 5 by means of a clamping ring 25. This clamping force also clamps and seals the sealing rings 20 and 21 against the nozzle brick 14.

It will be apparent that each connection 15 can be adjusted to take up any misalignments between the axes 11 and 12 after any interruption in the casting process.

The embodiments of Figs. 4 and 5 are similar to that of Figs. 1 to 3, the main difference being the location of the adjustable connections 15 on the underside 5a of the supply vessel 5 in the embodiments of Figs. 4 and 5. Thus, referring to Fig.

4, an angular cast metal guide means 27 is positioned below the supply vessel 5. The guide means 27 has a vertical portion 27a, which is constructed from top to bottom as follows: a metallic base shell 28 having a concave lower surface, a plate 29 having a complementary concave upper surface, an insert 30 positioned in a recess in the iower surface of the plate 29, and a telescopic tube 31 which is fixed to the top of an intermediate container 33. The insert 30 is adjustable in height, and cooperates telescopically with the telescopic tube 31 to form a seal for protection against oxidation. The telescopic tube 31 is carried by a cover 32 of the intermediate container 33. The cover 32 seals the intermediate container 33, and forms a bearing for the telescopic tube 31. A runner 34 is suspended in a cardan mount in the telescopic tube 31.A casting chamber 35 is defined within the intermediate container 33. An inert protective gas can be introduced into the casting chamber 35 if necessary. Means (not shown), are provided for ventilating the casting chamber 35. Ventilation is required during the start-up procedure. The intermediate container 33 is provided with adjustable connections 15, each of which is identical with that described above with reference to Fig. 3.

The adjustable telescopic connection between the insert 30 and the tube 31 enables the height 36 to be varied in dependence upon the ferrostatic pressure desired for the cast product.

The embodiment of Fig. 5 is identical to that of Fig. 4, except that the casting ladle 4 forms a supply vessel, so a separate supply vessel 5 is not required, and the shadow tube 18, which is sealingly connected to the base 37 of the ladle, leads directly into the guide means 27.

In the embodiment of both Figs. 4 and 5, the bath surface level 38 is controlled by an automatic control means (not shown).

Reference is made to the specification of our German Application No. P34 11 769.5 a copy of which has been filed with this specification, to the extent that it differs from the foregoing.

Claims

1. Apparatus for the horizontal continuous casting of metal, the apparatus comprising a supply vessel for containing molten metal, at least one horizontal continuous casting mould whose central longitudinal axis defines a casting axis, the supply vessel being provided with a respective orifice for supplying molten metal to the or each mould, wherein the or each mould is detachably connected to the supply vessel in alignment with the respective orifice by an adjustable connection, and wherein the or each orifice is defined by a respective perforated brick having an inserted nozzle brick, the or each adjustable connection being adjustable relative to the casting axis of the respective mould, and sealingly engaging the end portion of the respective nozzle brick.

2. Apparatus as claimed in claim 1, wherein the or each adjustable connection lies on one side of the supply vessel.

3. Apparatus as claimed in claim 1, wherein the or each adjustable connection is provided on the underside of the supply vessel inside an angular cast metal guide means which is connected directly to the or each horizontal continuous casting mould.

4. Apparatus as claimed in any one of claims 1 to 3, wherein the or each adjustable connection is provided with at least one concentrically arranged sealing ring, the sealing ring(s) defining a bearing surface which engages with the end portion of the nozzle brick.

5. Apparatus as claimed in claim 4, wherein the or each adjustable connection includes a spacer clamped against the free end of the associated nozzle brick, and wherein either the end portion of that nozzle brick or that spacer, which complement the associated bearing surface, is threedimensionally oval, for example spherical, in shape.

6. Apparatus as claimed in claim 3, or in either of claims 4 and 5 when appendant to claim 3, further comprising a cardan-mounted runner in the vertical arm of the angular cast metal guide means, the runner being connected to the supply vessel in air-tight manner.

7. Apparatus as claimed in claim 6, wherein the runner is sealed from the external atmosphere in the angular cast metal guide means.

8. Apparatus as claimed in claim 5 or claim 6, wherein the vertical arm of the angular cast metal guide means is of variable height.

9. Apparatus as claimed in claim 8, wherein the vertical arm of the angular cast metal guide means includes a telescopic section, whereby the height of the vertical arm can be varied in dependence upon the required ferrostatic pressure.

10. Apparatus as claimed in any one of claims 6 to 9, wherein the supply vessel and/or the angular cast metal guide means is provided with a base tap hole which can be sealed by means of a sealing member.

11. Horizontal continuous casting apparatus substantially as hereinbefore described with reference to, and as illustrated by, Figs. 1 to 3 or Figs. 1 to 3 as modified by either of Figs. 4 and 5 of the accompanying drawings.