ES339246A1 - Means for controlling casting - Google Patents

Abstract

Molten metal 22, from a ladle 20 placed in a pressure vessel 10, is forced up a tube 24 into a mould 28 by air from a conduit 18, the air flow being maintained by valves 52, 54 operated by controllers 62, 64 which are self regulating according to the difference in air pressure across an orifice 42 in the conduit. First, a graphite stopper 32 is lowered to close the mould ingate 38 and simultaneously to operate a switch to cause a twoway valve 98 to direct air (from the main or an auxiliary supply) to open a main valve 56 in the air conduit 18 and close an exhaust valve 60. The switch also operates a two-way valve 76 to supply the air to the controller 62 also, so that the latter allows the air to pass to the valve 52 to open it and permit and maintain a constant main air flow to the pressure vessel 10. The resulting flow of metal into the mould 28 raises the stopper to operate a switch to both cause the valve 76 to close the valve 52 and cause another two-way valve 88 to open the valve 54. The latter permits a lower rate of air flow to the vessel 10 until the mould 28 is filled. The final rise of the stopper 32 actuates a switch to cause the valve 88 to close the valve 54. The stopper is then lowered to close the ingate 38 and simultaneously operate the valve 98 to cause the main valve 56 to close and the valve 60 to open and exhaust the air from the vessel 10.