Explain about the Tray and Tunnel Dryers?
Tray and tunnel dryers are widely used in the food industry. In both cases the material being dried is supported on multiple trays, with the hot air being directed at high speed between and across the surfaces. Tray dryers operate in batch mode. However, two or more of the larger versions of this dryer may be linked to provide semi-continuous operation. Tunnel dryers provide a natural extension to this concept and are continuous. The tunnel dehydrator is by far one of the most flexible systems, which is in commercial use. In its simplest form it consists of a rectangular tunnel which will accommodate trucks containing the trays on which the product to be dried is uniformly spread.