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Commercial food drying continues to grow in importance
Newer equipment focuses on energy recovery and speed
Key to successful selection is to test the machine with your product
Food drying - once accompushed by putting food out in the sunlight - has become an important industrial process. Most commercial food drying in North America is now done by complex thermal/mechanical drying systems. Changes in this technology have made the process more precise and efficient. Food industries are periodically in the market for new food-drying equipment to meet increasing capacity requirements or to handle new products. The buying decision is complex and usually involves testing, unless the product has been in production and the parameters are known.
A wide range of food types can be dried, including fruits, nuts, potatoes, dairy products, meats, vegetables, and even prepared foods. For the food processor, it is important to be abreast of the full range of drying options. Now techniques such as gas-fired infrared drying and freeze-drying offer higher product quality and faster processing. High process speed and control are important because they help retain product flavors and aromas.
WIDE RANGE OF EQUIPMENT TYPES
In general, dryers can be classified as either direct or indirect drying systems. Direct drying is analogous to drying clothes on a line, versus the indirect system, which is analogous to frying on a stove. Direct drying is much more prevalent because the flow of air causes evaporative cooling, which helps preserve product properties. Single-stage continuous conveyor drying reduces product handling and is commonly used for fragile, solid products. Multiple-stage conveyor dryers are commonly used for solid products when the process requires a higher level of moisture removal.
In many dryers, solid food products and pastes are moved through the drying process via linked trays, perforated or mesh belts or in rotating drums....