Patent GB-1189333-A (GB)
Title: Continuous Casting Apparatus
IPC: B22D11/16
Filed: 1967-04-12
Abstract: 1,189,333. Continuous casting-machines. OGLEBAY NORTON CO. 12 April, 1967 [25 April, 1966], No. 16902/67. Heading B3F. [Also in Divisions C7 and F4] A continuous casting apparatus comprises a primary chamber 200 containing a ladle 206, pump means for either pressurizing the chamber to force molten metal through an electricallyheated passageway to a mould B or for producing a vacuum for degassing the molten metal. The chamber may be pressurized by air or by an inert gas which may be regulated to maintain a selected casting rate, and during de-gassing in a vacuum the molten metal in the ladle 206 may be stirred by induction coils. The ladle is re-charged with molten metal from a secondary chamber 218 by means of a stopper control 230 and gate valve 222. A vacuum is drawn in the primary chamber 200 so that as the molten metal is drawn in it is stream de-gassed. In a modification the primary ladle (302), (Fig. 2, not shown), can be recharged without interrupting the pressure feeding of the mould B. A secondary chamber (304) is positioned above a primary chamber (300) and connected thereto to pass molten metal by a stopper control (326) and gate valve (330). The primary and secondary chambers are connected to a common pressurizing source (312) so that pressure equalization can be obtained in the chambers (300), (304) before the gate valve (330) and stopper control (326) are opened to pass molten metal from the secondary ladle (306) to the primary ladle (302). The secondary chamber (304) can have a vacuum drawn therein by pump (316) to de-gas the molten metal which is stirred by induction coils (318). Mould construction.-The mould B is of rectangular cross-section formed of plates having water-cooling passages therein. In the example shown in Figs. 5-8 (not shown), the first part of the mould is of fixed proportions but a second part has side walls articulated to follow the contraction of the solidifying cast strand. The articulated side walls comprise a spring-biased pivoted section (63), (65) and a spring-biased floating section (67), (69) at the exit end of the mould. The spring biasing may be replaced by motor (136), (Figs. 10, 11, not shown) driven rack and pinions that move the articulated sections and which may incorporate a pressure sensing cell (244) that acts to start the motor (136) to move the wall sections (63), (65), (67), (69) inwards when they lose contact with the shrinking cast strand. The top and side walls are constructed of copper faced with graphite inserts (96) and the bottom wall (66) is constructed of ductile iron faced with carbide or Stellite (Trade Mark) and may be oscillated ultra-sonically to prevent it sticking to the cast strand. Mould lubrication.-The bottom wall of the mould supporting the weight of the east strand may be lubricated by a tape lubricant 98 stored in roll form with one end fixed to the starting bar 100 and fed through the mould with the cast strand. The tape may be made of steel or of steel strips embedded in glass which melts to prevent sticking of the strand to the mould wall. In a modification (Fig. 3, not shown), rape seed oil is fed under pressure to the bottom surface of the mould. Lubrication may also be supplied to the mould walls by means of ducts (144) and (146), (Fig. 9, not shown).