摘要:
The invention relates to a drying apparatus (1) for drying bulk material comprising -a closed circulation conduit (4) being adapted to be filled with a drying medium when said drying apparatus is in operation -a fan (12) connected into said closed circulation conduit for generating a flow of drying medium, -heating means (13) connected to the fan (12) for indirectly heating the drying medium, -inlet feeding means (6) connected to said closed circulation conduit (4) for feeding bulk material into the closed circulation conduit, -a drying enclosure (7) connected to the inlet feeding means (6) wherein said bulk material is dried by transfer of thermal energy from said drying medium, -separating means (8;8') connected to the drying enclosure (7) for separating bulk material from said drying medium, -a surplus steam outlet (14) connected to said closed circulation conduit (4) for releasing surplus steam (10), wherein said separating means (8) comprise a plurality of cyclones (8a-d;8'a-d). The present invention also relates to a process for drying bulk material using said drying apparatus and to the use of said drying apparatus to dry wood based bulk material or agricultural based bulk material. The present invention also relates to a combined heat and power plant comprising said drying apparatus.