ARC FURNACE COVER ASSEMBLY Russian patent published in 1999 - IPC

FIELD: structural parts of electric furnaces. SUBSTANCE: cover assembly for molten-metal furnace has lower cover that closes it and carries on its inner space first spraying device in the form of tubes with nozzles, first device for feeding coolant to tubes, and first outlet device for evacuating coolant from enclosed space of lower cover; upper cover with hole through which electrode is vertically inserted into furnace interior; this cover is built up of walls forming its enclosed annular space accommodating second spraying device made of many tubes with nozzles, second coolant feeding device for tubes, and second coolant outlet device; in addition, cover is provided with first hose interconnecting pipelines of collectors of first and second spraying devices and second hose interconnecting upper-cover outlet device with lower-cover one; upper wall of lower cover has flat stepped part spaced through certain distance from high- strength side wall and is arranged around inner hole of lower cover; stepped part of upper wall of lower cover mounts upwards beveled lower wall of upper cover which is free to slide in all directions. EFFECT: minimized thermal stresses during downward movement of electrode and minimized heat loss above inner hole of bottom arch of cover. 4 cl, 6 dwg