The characteristics of the air
Dryer: (1) The drying speed is fast, the solid materials are dispersed and suspended in the air flow, and the gas-solid two phases have a large heat and mass transfer area. The hot gas inlet velocity is high (20-40m/s), the relative velocity between gas-solid two phases (especially the acceleration zone) is very large, and the average volumetric heat transfer coefficient ha is 3000-7000 W/(m3·K) which is better than other types of drying. The height of the air dryer is much smaller with the same production capacity. (2) The gas-solid co-current operation is in accordance with the basic law of material drying. The constant speed drying section provides very strong drying conditions, and the lower speed drying section and mild drying conditions can use high temperature gas as the drying medium. (3) The drying time is short. The material starts from entering the dryer and disengages from the gas-solid two phases. The whole drying process does not exceed one second. Airflow drying, also known as rapid drying or flash drying, is particularly suitable for heat-sensitive materials. dry. (4) In the air dryer, the solid material flows in a plug flow. The drying time experienced by each particle is approximately the same, and the moisture content of the dried product is uniform. (5) Simple structure, less equipment investment, small footprint, convenient operation, stable performance, and small maintenance.
