RECIRCULATING DRYING PLANT Russian patent published in 1998 - IPC

FIELD: drying material by means of air used as drying agent; farming for drying grain and wood-working industry for drying lumber. SUBSTANCE: recirculating drying plant includes drying chamber provided with air permeable bottom and filled with material to be dried. Drying chamber is connected to recirculating passage by means of air supply and air discharge dusts forming closed recirculation loop for drying agent. Arranged in recirculating passage which is heat-insulated on its outside similarly to drying chamber are fan and thermal pump unit which has cascade construction: it consists of two thermal pumps connected ins series. EFFECT: enhanced efficiency. 11 cl, 2 dwg