Industry: Fruit and Vegetable Preserving and Specialty Food Mfg (NAICS 3114)
Process Brief: Moisture in fruits and vegetables is removed using a heated drum.
Energy source: Steam/Natural gas
Energy Intensity: 2,350-2,700 Btu/lb of water in the product
Drum driers are used to with liquids or slurries, especially in the production of mashed potato flakes and yeast. In each case, the heated drum is rotated in a pool of the product or the product is fed onto the surface of the drum. The product forms a liquid on the heated drum and the moisture evaporates. The dried product is then scraped from the drum. Most commonly, the drum is heated by condensing steam; but, in some cases, direct heating with natural gas is used. Drum driers have high capital cost and usually cannot be used for more than one product. They have the advantage of being fairly efficient and capable of high throughput.
In contrast with indirect drying on a drum dryer, a large quantity of hot air is necessary for “direct drying” in order to achieve evaporation. In indirect drying, heat is transferred by, for instance, steam to the (metal) wall, which in turn transfers it to the product on the other side of the wall. All the heat transferred by the wall is also used to dry the product and does not leave the machine or chimney unused. This makes indirect drying a much more efficient process. An extra advantage is that large dust recovery systems (such as filters) are no longer necessary due to the absence of drying gas.
2741 PD Waddinxveen, Holland
P.O. Box 375
2740 AJ Waddinxveen
Telephone: (+31) 182 – 623723
Web site www.gmfgouda.nl
R. SIMON (DRYERS) LTD
PRIVATE ROAD NO. 3,
COLWICK INDUSTRIAL ESTATE
COLWICK, NOTTINGHAM NG4 2BD ENGLAND
Telephone: +44 (0)115 961 6276
Web site www.simon-dryers.co.uk