Explain the Conveyor (or Band) Dryers?

In the conveyor (or band) dryer, the product is distributed on a moving belt, typically of a perforated plate, that passes through a tunnel like structure in which vertical airflow is strictly controlled. With the exception of transfer operations (or occasional deliberate stirring of the bed), the individual particles remain fixed in position with respect to one another. This type of drying system is very similar to the tunnel system except that the material is conveyed through the hot air system on a continuous moving belt. The system has the advantage that the high cost of handling products both before and after drying using trays is substantially reduced. This drying system is used for downstream operations such as cereal puffing.