Abstract: A flow dryer is disclosed for comminuting and dehydrating matter using a stream of hot gas, said flow dryer being of the type employing an inlet duct in series with an agitator followed by a drying duct, the agitator having an inlet communicating with the inlet duct and an outlet communicating with the drying duct in order for hot gas to flow through the agitator, and control means operable to vary the residence time of matter in the agitator by varying the required exit characteristics for comminuted matter leaving the agitator through the agitator outlet.

Abstract: Dehydration tower (22) for previous agitated organic material carried by a heated air stream, the tower containing a selectively rotatable series of baffles (42, 43, 44, 45) for varying the path length of the material, and thus the residence time, in the tower, as the material passes up the tower on one side of the vertical series of baffles (49) and then down the other side of the series.