| 摘要 |
1,021,872. Continuous metal-heating furnaces. STEIN & ROUBAIX. Aug. 13, 1962 [Nov. 13, 1961], No. 29780/62. Heading F4B. In a rotary hearth furnace, divided into heating zones by radial partitions 1-6, metal workpieces are preheated by the secondary combustion of the reducing atmosphere withdrawn from a burnerless heating zone C through passages 11a near the commencement of zone C, Fig. 3, and through passages 13 from the preheating zone B, Fig. 4. The workpieces are heated in zone C only by the hot reducing atmosphere produced by burners 10 in the following heating and equalizing zones D, E, F. The combustion products from the zone B are burnt with air supplied at 18, cooled by additional air supplied at 21 and fed through heat exchangers 44, 43 and 40 to the flue. The fuel gas, primary air and secondary and tertiary combustion air are heated in exchangers 40, 43 and 44 respectively. The total combustion air, supplied from a single blower is regulated in accordance with the fuel supply, and the fuel and air supplies to the equalizing zone F and heating zones D, E are controlled in accordance with the temperatures in these zones. The secondary air supply to preheating zone B is also controlled in accordance with the temperature in this zone, the remaining air being fed to the flues for tertiary combustion. A separate blower supplies the cooling air to the flues. |
