| 摘要 |
598,930. Air turbine plant. AKT.- GES. FUR TECHNISCHE STUDIEN. Aug. 8, 1945, Nos. 20319, 20320 and 20321. Convention dates, Aug. 12, 1944, Oct. 14, 1944, and Oct. 26, 1944. [Class 110 (iii)] The invention relates to a plant delivering compressed air to a consumer in which air is compressed in at least one compressor to a maximum pressure which is higher than the pressure necessary for the operation of the consumer plus the pressure drop in the connecting conduits. The plant comprises a compressor and a heater in which part of the compressed air is heated by an indirect supply of heat before being expanded in a turbine driving the compressor. The exhaust of the turbine is partly used as combustion air in the heater and the remaining part of the compressed air is withdrawn from the compressor or in any case not later than before the last stage of the turbine for use in the consumer. The invention consists in heating the compressed air before it enters the consumer. In the plant shown, Fig. 1, the air is compressed in a three-stage compressor 1, 2, 3, -heated indirectly in the heating system 5 of a heater 6 and then expanded in a turbine 9 driving the compressor. A part of the compressed air is withdrawn at the low pressure end of the turbine and passed through the heating system 10 of the heater 6 to the consumer, in this case, a blast furnace 4. In Fig. 2, the air for the consumer is branched off at the outlet of the first stage 12 of the compressor and passes through an independent heater 17. In a modification of this arrangement, the exhaust from the turbine 20 may be used to supply combustion air to the heater 17 and also to supply another consumer of hot air, such as a pre-heater for the fuel. In a further modification, the heater 17 is replaced by one or more pairs of regenerators heated by the blast furnace gas. In all the arrangements, the amount of air supplied for combustion purposes can be at least twice as large as the quantity required for combustion so that slag formation on the heating surfaces is prevented. If desired, the point from which the air for the consumer is withdrawn may be a variable one and the fuel for the heaters blast furnace gas. The amount of air supplied to the consumer may be controlled either (i) varying the amount of intercooling in the compressor ; (ii) by means of byepass pipes and valves on the compressor or turbine ; (iii) by varying the quantity of air compressed to the final pressure ; (iv) by varying the quantity of air expanded in the turbine or the temperature to which this air is heated ; (v) by varying the speed of the turbine-compressor unit or by any combination of these methods.
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