| 摘要 |
<p>PCT No. PCT/GB91/00524 Sec. 371 Date Oct. 3, 1991 Sec. 102(e) Date Oct. 3, 1991 PCT Filed Apr. 4, 1991 PCT Pub. No. WO91/15320 PCT Pub. Date Dec. 17, 1991.The invention provides a method of controlling the flow of molten metal from a holding vessel such as a tundish through a discharge orifice into a receptacle such as a mould; the method comprising (i) providing within the holding vessel a flow control chamber comprising a down-flow chamber separate from but in fluid communication with the interior of the holding vessel, the down-flow chamber having an outlet at its lower end, said outlet leading to or forming part of the discharge orifice, and an opening towards or at its upper end; (ii) creating a gas pressure within the flow control chamber sufficient to allow molten metal from the holding vessel to pass through the opening to establish in the lower end of the down-flow chamber a column of molten metal with a volume of gas occupying the upper end of the flow control chamber and serving to separate the column of molten metal from the opening, whereby an equilibrium is established between molten metal passing through the opening and molten metal passing out through the discharge orifice such that the height of the column of molten metal in the down-flow chamber remains substantially constant; and (iii) (a) reducing the said volume of gas, thereby to increase the height of the column of molten metal and thus the flow rate through the discharge orifice, or (b) increasing the said volume of gas, thereby to reduce the height of the said column and thus the said flow rate. The flow control chamber suitably is a refractory body having a hollow interior divided by a central weir into up-flow and down-flow chambers. The invention also provides a refractory flow control chamber per se and a flow control system including the chamber.</p> |
