Design and Application of Cylinder-Air Current Type Dryer

To diminish the fluctuation of moisture content in dried cut tobacco and reduce the amounts of clustered tobacco and over-dried tobacco, a cylinder-air current type dryer was designed, it incorporated the technological advantages of cylinder dryer and pneumatic dryer. The designed dryer was composed of feeding/ discharge airlocks, drying cylinder, combustion furnace, main technological fan, etc. The cut tobacco in cylinder uniformly contacted with hot air containing a certain amount of steam to conduct heat and moisture exchange. The moisture content in dried tobacco was precisely controlled by regulating drying temperature, drying time, flow rate of water and exhausted moisture volume. The results of application showed that: 1) The moisture content in dried tobacco was consistent and stable with the deviation of ± 0.5%, the dried tobacco held good color and shape with the filling value of ≥4.3 cm3/g and kept natural tobacco aroma. 2) The regulating range of technical parameters satisfied the need of grouping processing and fine processing. 3) Thanks to simple in structure and free from leakage, the new dryer reduced labor intensity and maintenance cost.