The machine (1) includes a tunnel structure (2) which defines a chamber (8) with inclined, downwardly converging longitudinal side walls (9) and in which a substantially horizontal conveyor (10) for conveying a layered flow of shredded tobacco (T) from the input end (6) to the output end (7) of the chamber (8) extends adjacent the lower edges (9b) of the converging side walls (9). A ventilation system (16-25) is provided in this latter, having a delivery manifold (16) which extends above the conveyor (10), an array of vertical tubes (17) which extend from the delivery manifold (16) to a predetermined distance from the conveyor (10) between the lower edges (9a) of the converging side walls (9), a return manifold (18) communicating with lateral regions of the chamber (8) situated to the sides of the array of tubes (17) and above the converging side walls (9), and air conditioning and recycling apparatus (20-25) interposed between the outlet (23) of the return manifold (18) and the delivery manifold (16) for inducing flow of conditioned air through the tubes (17) towards the conveyor (10) in such a way that the air leaving the tubes (17) creates a bed of air above the conveyor (10) for fluidizing the layered flow of tobacco (T).
展开▼