Foam Mat Driers – Continuous, Liquid, Heat Sensitive

Industry: Fruit and Vegetable Preserving and Specialty Food Mfg (NAICS 3114)

NAICS process:

311411 Frozen Fruit and Vegetables

311421 Canned Fruit and Vegetables

Process Brief: Moisture in fruits and vegetables is removed using hot air.

Energy source: Steam/Natural gas Energy Intensity: 1,700-28,608 Btu/lb of water in the product

Foam mat driers are a variation of the standard conveyor driers. Foam mat driers help process fruit juices into an intermediate product that can later be ground into a fine powder. First, the fruit juice is mixed with a stabilizer and is aerated with nitrogen or air to produce a thick foam. The foam is applied to a perforated belt at a depth of 1/10 inch. The foam is dried in a conveyor-type drier that is approximately three times faster than drying a juice that has not been foamed.

Capital costs for foam mat driers are high because of the large surface area needed to process large quantities of foamed fruit juice. Also, the driers are not well suited to processing other products. Despite these disadvantages, foam mat driers produce most of the industry’s dried fruit juice.

Energy Efficiency

Foam-mat drying: Energy and cost analyses

T. Kudra1* and C. Ratti2

1CANMET Energy Technology Centre –Varennes, Varennes, Quebec J3X 1S6, Canada; and 2Department of Soils and Agri-Food Engineering, Laval University, Quebec, Quebec G1K 7P4, Canada. *Email: tkudra@nrcan.gc.ca