| 摘要 |
1,172,863. Metal melting furnaces. GAS COUNCIL. 2 Jan., 1967 [27 Jan., 1966; 18 June, 1966], Nos. 3634/66 and 27330/66. Heading F4B. A metal melting furnace, particularly for Al alloys, comprises a preheating shaft 19 with feed hopper 35 and lower heat-resisting metal rams 32 feeding semi-molten charge on to the hearth 26 of a melting chamber 13 with gas burners 34 and a roof 17 curving downwardly to a dividing wall 14 formed at its base with a jack arch 24 of spall-resistant refractory cooled by an air casing 25. Waste gases ascend the shaft 19 and operation of the rams 32 is intermittent being controlled by a thermostat set to operate when metal on slope 27 is softened. The furnace walls comprise an outer metal shell 20 enclosing layers 21, 22 of insulation and a lining 23 of refractory. The hearth 26 slopes downwardly to a taphole feeding a rotary holding furnace, Fig. 2 (not shown), heated by a radiant tube. Waste gases from this tube are cooled and fed back to the holding furnace as a neutral atmosphere. Weight-responsive cells in a support for the holding furnace control the gas and air lines of the melting furnace through an electric switch and motorized valves.
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