Industrial Food Tunnel Dryer Manufacturers

Industrial food tunnel dryers — types and applications

A tunnel dryer is a continuous or semi-continuous drying system in which the product moves through a long enclosed tunnel in which heated air is circulated. Two main configurations exist: belt-type tunnel dryers (the product is conveyed through the tunnel on a continuous mesh or solid belt — see belt dryers for food applications); and trolley-type (truck-type) tunnel dryers (product loaded on trolleys with stacked trays is pushed or conveyed through the tunnel on rails — batch movement through a continuous drying environment). Trolley tunnel dryers are widely used in pasta drying (where long, controlled drying curves are required to prevent cracking); large-scale bakery (biscuit, cracker, and cookie drying after baking or before packaging); and industrial scale herb, spice, and food ingredient drying where the product is on trays and volume requires a semi-continuous approach. The drying zones in a tunnel dryer can be set to different temperatures and air humidity levels — allowing a multi-stage drying profile to be programmed for products sensitive to rapid drying.