摘要 |
A refractory structure comprises (a) a body of refractory concrete contg. >=1 pouring hole; with (b) >=1 reinforcing element placed in (a) or forming one surface of (a) and mechanically locked in (a); or (c) a channel for a service fluid is provided in (a); or (d) the pouring hole is formed by an insert with better resistance than material (a); or (a, b, c); or (a, b); or (c, d); or (a, b, c, d). - The refractory structure pref. has a sinusoidal channel (c), esp. a channel extending round >=180 degrees of the circumference of the casting hole. Channel(c) may be formed by porous material permeable to gas and extending to the casting hole. The fluid used in channel (c) may be a hot gas used to heat the stopper; compressed air used to cool the stopper; a gas which does not oxidise the molten metal; or an inert gas cooling the stopper.
|