Drying machine for shredded tobacco, in particular for rolls of expanded shredded tobacco

A machine (1) for drying shredded tobacco (T), including:

• a tunnel structure (2) with an input end (6) and an output end (7) in which a chamber (8) with inclined longitudinal, downwardly-converging side walls (9) is defined;
• a substantially horizontal conveyor (10) which extends within the tunnel structure (2) adjacent the lower edges (9b) of the converging side walls (9), for transferring a layered flow of shredded tobacco (T) from the inlet (6) to the outlet (7);
• and
• a ventilation system (16-25) including:
• a delivery manifold (16) which extends over the conveyor (10);
• an array of essentially vertical tubes (17) which extends 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 at the sides of the array of tubes (17) and above the converging side walls (9);
• and
• air conditioning and recycling means (20-25) interposed between the outlet (23) of the return manifold (18) and the delivery manifold (16), and adapted to supply a flow of conditioned air through the tubes (17) towards the conveyor (10) in such a way that, in use, the air leaving the tubes (17) creates a bed of air above the conveyor (10) for fluidizing the layered flow of tobacco (T), and the air emitted from the tubes (17) is then returned to the return manifold (18) through the lateral regions of the chamber (8) in such a way that any tobacco particles carried by the return air flow in the lateral regions of the chamber (8) fall under gravity onto the converging side walls (9) and down on to the conveyor (10).