| 摘要 |
1,100,631. Heating combustion air; feedwater heating. SVENSKA ROTOR MASKINER AKTIEBOLAG. 30 April, 1965 [30 April, 1964], No. 18267/65. Headings F4A, F4B and F4K. A coal fired boiler plant (not shown) includes a regenerator using flue gases for preheating secondary air in portion 3a, and for preheating primary air used also for drying in a coal mill in portion 3i. The temperature of the primary air used for drying is controlled in addition to controlling the flue gas flow to the regenerator, by use of a recuperator 1 in series with the regenerator 3, heat being extracted from the primary air by a controlled flow of part of the boiler feed water therethrough. The hot flue gas flow R is divided into flows R1, R2, the flow R2 being passed through feedwater heater 2 within the boiler, and then being branched into flows R3, R4, the flow R4 being used to preheat the secondary air and the joint flow R1 and R3 being used to heat the primary air. The gas flows are controlled by dampers I, II, III. The heated primary air has its temperature controlled in recuperator 1 by the partial flow of boiler feedwater taken off between steam heated feedwater preheaters 10, 11 and controlled by valves IV, V. In a modification (Fig. 1) the cooling recuperator 1 is situated in the flue gas line leading to the inner part of the regenerator for heating the primary air, and not in the air line itself. |
