| 摘要 |
<p>A tunnel drier for drying continuous lengths of material is operated with superheated steam or with a steam-rich steam-gas mixture. The drying channel (10) is for this purpose made essentially gastight and is provided at its inlet side and its outlet side with respective lock zones (16,18). The medium emerging from the drying channel (10) through an outlet duct (26) is fed back again via a return duct to the inlet side of the drying channel (10), only the quantity of steam taken out of the length of material being removed from the circuit. The heat contained in this steam is partially taken out of the exhaust steam by a heat pump (30,32,34,36) and is used for heating the heating medium flowing back to its operating temperature. The energy consumption of the drying plant and the load on the environment are thus considerably reduced. <IMAGE></p> |
