system for maintaining warm metallic masses merged with prey over composition, particularly the masses merged of steels and oven to keep warm for the implementation of the system

摘要

1375431 Protective atmospheres WIENER SCHWACHSTROMWERKE VERTRIEBS GmbH and BADISCHE ANILIN & SODAFABRIK AG 4 Jan 1972 [4 Jan 1971] 348/72 Heading F4B [Also in Division C7] Atmospheric air above the surface of a metal melt is slowly displaced by introducing a gas which is denser than air and is inert to the metal melt. The pressure of the gas is reduced before it enters the furnace chamber holding the metal melt so that the gas spreads over the surface of the melt to form a protective layer of the gas. The volume of gas introduced is equal to at least 1À3 times the volumetric capacity of the furnace, to maintain above the melt a gauge pressure of 0À05 to 0À5 atmospheres. The gas is preferably argon, and enters the furnace via a conduit 19, an expansion chamber and a gasporous brick 20 disposed adjacent the surface of the melt. Alternatively, two bricks may be used, one on either side of the furnace cover (see Fig. 2) if the furnace should include a pouring spout, then the gas is directed to form a protective layer over the melt in the spout. In an alternative embodiment, instead of a fixed gasporous brick, a vertically adjustable inverted ceramic funnel or a pot-shaped, gas-permeable refractory brick (see Figs. 5, 6) may be used.