| 摘要 |
<p>An air heating system for a grain dryer employs air for at least 2 hot drying stages and one cooling stage. Air on its way to the drying stages is passed through the sec. circuit of a heat exchanger. The prim. circuit of the heat exchanger is supplied with hot gases other than steam, e.g. from an oil fired, direct air heater. Air to be used for drying is passed at least once through the grain, partic. for cooling purposes, and then channeled through the sec. circuit of the heat exchanger, at no time contacting a wall directly exposed to flame. In either drying stage, the drying air can be supplemented by air coming directly from the air heater and which has not been passed through the grain. The system may comprise two heat exchangers in series with a second air heater reheating air between the first and second exchangers. The system is used for heating air which contact dries the moisture from cereal grains.</p> |
