BG104221A - Electric furnace - Google Patents

Abstract

The electric furnace, in particular with ohmic heaters is used in machines for pneumatic metals and alloys casting both with low pressure, and with counter pressure. In the furnace to recuperators (4, 14) are fitted, utilizing the heat energy of the operating gas leaving the furnace. Each of them serves a respective zone in the furnace. One of the recuperators (4) serves a "heat zone" in which a crucible with metal smelt (12) and ceramic supports with ohmic heaters (13) are fitted. The other recuperator (14) serves a "cold zone" including the space around the housing (1) of the furnace where heat insulation (15) is laid. In this way, each of the recuperators (4, 14) recuperates the heat energy of the operating gas leaving the furnace to an extent corresponding the respective zone, that any chance of allowing in the "cold zone" of operating gas with temperatures higher than that of the zone is eliminated. The two recuperators enable the even filling, or discharging, respectively, of the furnace, avoiding any differences in the pressures which reduces the time of these operations. The increased heat-exchange surface as a result of the employment of two recuperators reduces the heat losses with the operating gas leaving the furnace. 1 claim, 1 figure