HORIZONTAL CONTINUOUS CASTING APPARATUS

Abstract: In horizontal continuous casting apparatus, the longitudinal axis of the mould passage (21) may not be aligned with the longitudinal axis of the nozzle (19) in the wall of the tundish (13). To overcome this difficulty, the nozzle (9) and the feed tube (5) which is located between the nozzle (9) and the mould passage (2) are arranged so that the longitudinal axis of the outlet of the feed tube (5) is aligned with the longitudinal axis of the mould passage (21) and is offset vertically with the longitudinal axis of the inlet of the nozzle (19).

Description: HORIZONTAL CONTINUOUS CASTING APPARATUS This invention relates to horizontal continuous casting apparatus where the longitudinal axis of the mould passage provided by the mould assembly is arranged horizontal and the molten metal stored in a tundish is fed to the mould passage by way of a nozzle in a side wall of the tundish and a feed tube connecting the nozzle to the mould assembly. In practice, the mould assembly is fixed, the feed tube is clamped to the mould assembly to prevent leakage of molten metal between the outlet of the feed tube and the inlet of the mould passage, and the tundish is urged towards the mould assembly to provide a leak-proof joint between the outlet of the nozzle and the inlet of the feed tube. Downstream q£ the outlet of the mould passage there is a structure for supporting the casting horizontally as it is withdrawn from the mould and whilst it is cooled. This structure is often in the form of a roller table. Clearly, the casting leaving the mould passage has to have its lower surface aligned with the upper surface of the roller table and, consequently, the position of the longitudinal axis of the mould passage relative to the upper support surface of the roller table depends upon the cross-sectional dimensions of the mould passage and, hence, of the casting. If the casting apparatus is to be capable of casting workpieces of different cross-sections, then different moulds have to be employed and the axes of the moulds have to be raised and lowered with respect to the roller table. It is desirable for the longitudinal axis of the mould passage to be aligned with that of the feed tube and that of the outlet of the nozzle. Consequently, if the longitudinal axis of the mould passage is raised or lowered, it is usual to attempt to raise or lower the tundish. This can lead to difficulties, bearing in mind that the tundish supports a mass of molten metal. It is also known for two or more moulds arranged side-by-side to be fed simultaneously from a tundish having two or more nozzles connected to the moulds by separa e„.fe≤,G ti ss. If the moulds produce castings of different cross-sections, then the tundish has to be tipped sideways so that the longitudinal axes of the mould passages are coincident with those of the feed tube and the nozzles. Tipping of the tundish is not convenient. An object of the present invention is to overcome these difficulties. According to the present invention, horizontal continuous casting apparatus comprises a tundish having a refractory nozzle fitted in a side wall thereof, said nozzle having an inlet and an outlet; a mould assembly having a horizontal mould passage therethrough; a refractory feed tube having an inlet in communication with the outlet of the nozzle and an outlet in communication with the inlet of the mould passage to provide a closed duct between the outlet of the nozzle and the inlet of the mould passage; characterised in that the longitudinal axis of the outlet of the feed tube is aligned with the longitudinal axis of the mould passage and is offset vertically from the longitudinal axis of the inlet of the nozzle. The refractory nozzle may have an opening therethrough which has the longitudinal axis of the inlet offset from the longitudinal axis of the outlet. In use, the longitudinal axis of the outlet of the nozzle is aligned with the longitudinal axis of the mould passage and with the longitudinal axis of the feed tube. Alternatively, the opening through the refractory nozzle has the longitudinal axes of its inlet and outlet ends aligned but the feed tube has the longitudinal axis of its inlet end aligned with the longitudinal axis of the outlet of the nozzle but vertically offset from the longitudinal axis of its outlet end which is aligned with the longitudinal axis of the mould passage. With the present invention, moulds for producing castings of larger and smaller cross-sections can be employed- without having to raise or lower or tip the tundish. In order that the invention may be more readily understood, it will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a sectional side elevation of conventional horizontal continuous casting apparatus; Figure 2 is a diagrammatic side elevation of continuous casting apparatus in accordance with the present invention; Figure 3 is a diagrammatic side elevation of continuous casting apparatus in accordance with a second embodiment of the present invention; f A m- m dtnά 5 are a sectional ; s de elevation and an end view, respectively, of a refractory nozzle in accordance with one embodiment of the present invention; and Figure 6 is a diagrammatic side elevation of continuous casting apparatus in accordance with a third embodiment of the present invention. A part of a horizontal continuous casting mould assembly is indicated by reference numeral 1. The mould passage is indicated by reference numeral 2. A break ring 3 is located at the inlet end of the mould passage and abutting against the break ring there is a refractory feed tube 5. A clamp 7 fits around the feed tube and means (not shown) associated with the clamp serve to urge the end of the feed tube into engagement with the break ring which, in turn, is forced into the inlet end of the mould passage 2. The opposite end of the refractory feed tube 5 fits into a recessed end portion of a refractory nozzle 9 mounted within a seat 11 located in a side wall 13 of a tundish 15 for containing molten metal. The tundish is mounted on jacking means 17 whereby the tundish can be raised or lowered so that the longitudinal axis 19 of the nozzle 9 is aligned with the longitudinal axis 21 of the mould passage. The tundish is usually mounted on wheels or the like and means (not shown) urge the tundish in the direction towards the mould to make a fluid type connection between the outlet of the nozzle and the inlet of the feed tube. In use, molten metal from the tundish flows through the nozzle and the feed tube into the mould passage where contact with the cooled wall defining the mould passage causes the molten metal to start to solidify to form a casting defined by the shape of the mould passage. Referring now to Figure 2, the mould 1, feed tube 5 and nozzle 9 are shown in more generalised form. A pair of hydraulically operated hooks 23 which engage with a flange on the feed tube 5 show how the feed tube can be urged into engagement with the mould assembly. Similarly, a hydraulically operated jack shown by reference 25 indicates how the tundish can be urged towards the mould assembly 1. At the outlet end of the mould passage there is a support in the form of a roller table 27. The mould assembly 1 is raised or lowered so that the lower side of the casting leaving the mould passage is supported on the upper surface of the roller table 27. As the mould assembly is raised or lowered so that the lower side of the mould passage is aligned with the roller table 27, the longitudinal axis 21 of the mould passage is raised and lowered. The longitudinal axis of the feed tube 5 is aligned with the longitudinal axis 21 of the mould passage but this axis may not then be vertically aligned with the longitudinal axis of the nozzle 9. As can be seen from Figure 2, the longitudinal axis 19 of the inlet end of the nozzle is. offset vertically with respect to the longitudinal axis 21 of the mould passage. It is, therefore, necessary for the nozzle 9 to be so arranged that the longitudinal axis of its inlet is aligned with axis 19 and the longitudinal axis of its outlet is aligned with axis 21. Figures 4 and 5 show in more detail a typical nozzle 9' having an inlet 29, the longitudinal axis 31 of which is offset vertically from the longitudinal axis 33 of the outlet 35 of the nozzle. The outlet is provided in a recessed part of the nozzle to enable the feed tube to project into the recessed part. Figure 3 shows an alternative embodiment of the invention. A different mould assembly 1A has a mould passage 2A where the longitudinal axis 21A of the mould passage is nearer to the support 27 than the axis 21 of Figure 2. Hence, axis 21A is displaced vertically with respect to the axis 19 of the inlet end of the nozzle by a greater extent than is the case shown in Figure 2. A different nozzle 9A is employed. The means for securing the feed tube to the mould assembly and for biasing the tundish towards the mould assembly are not shown in Figure 3, but they may be the same form as shown in Figure 2 or, alternatively, they could be in the form of spring- loaded bolts or the like. An alternative arrangement is shown in Figure 6 where the nozzle 9B in the wall 13 of the tundish has an inlet aligned with its outlet and with the outlet of the nozzle aligned with the inlet of the feed tube 5B. However, the longitudinal axis 19 of the nozzle is offset vertically from the longitudinal axis 21 of the mould passage so that the longitudinal axes of the inlet and outlet of the feed tube are offset vertically from one another. By changing the feed tube and the nozzle it is possible to connect moulds having passages of different cross-section with the tundish. Furthermore, when two or more moulds are fed simultaneously from the same tundish, the moulds may have passages of different cross-section and, by employing appropriate nozzles and feed tubes, it is possible to feed the two or more moulds without having to tip the tundish and maintain the lower surfaces of the moulds at a common level with each other and the roller tables.

Claims: Claims : 1. Horizontal continuous casting apparatus comprising a tundish having a refractory nozzle fitted in a side wall thereof, said nozzle having an inlet and an outlet; a mould assembly having a horizontal mould passage therethrough; a refractory feed tube having an inlet in communication with the outlet of the nozzle and an outlet in communication with the inlet of the mould passage to provide a closed duct between the outlet of the nozzle and the inlet of the mould passage; characterised in that the longitudinal axis of the outlet of the feed tube is aligned with the longitudinal axis of the mould passage and is offset vertically from the longitudinal axis of the inlet of the nozzle. 2. Horizontal continuous casting apparatus as claimed in claim 1, characterised in that the longitudinal axes of the inlet and outlet of the feed tube are aligned with the longitudinal axis of the mould passage and the longitudinal axis of the outlet of the nozzle is aligned with the longitudinal axis of the mould passage. 3. Horizontal continuous casting apparatus as claimed in claim 1, characterised in that the longitudinal axes of the inlet and outlet of the nozzle are aligned with the longitudinal axis of the inlet of the feed tube and are offset from the longitudinal axis of the outlet of the feed tube. 4. Horizontal continuous casting apparatus as claimed in claim 2, characterised in that the cross- sectional dimensions of the outlet of the nozzle are smaller than the corresponding cross-sectional dimensions of the inlet of the nozzle. 5. Horizontal continuous casting apparatus as claimed in claim 2 or 4, characterised in that the outlet of the nozzle is defined by a recessed portion of the nozzle and the inlet of the feed tube projects into the recessed portion of the nozzle.

Inventors: STONECLIFFE DAVID, STONECLIFFE, DAVID
Applicants: DAVY MCKEE SHEFFIELD, DAVY MCKEE (SHEFFIELD) LIMITED
Application year: 1990
Main classification: B22D11
IPC codes: B22D11