ఫుడ్ ప్రాసెసింగ్ & టెక్నాలజీ జర్నల్

నైరూప్య

Processing Aids for Improving Heat Transfer during Drying of Granular Food Materials

Chenchaiah Marella and K. Muthukumarappan

The comparative low price of energy in the past discouraged any emphasis on energy conservation in drying of food products. But under the circumstances of ever increasing energy prices, it is the need of the hour to look for improved energy utilization. In dairy and food industry a large number of products are dried. Previously this operation was carried out in a single stage, necessitating the dryer to operate at higher air out let temperatures. To improve this, dryers were developed with two and three stages. Additional stages brought about significant savings in the energy requirements. Fluidized beds have been included as second and third stage dryer in conventional dryers. Inclusion of vibrations, centrifugal beds, immersion heaters etc have been tried to improve the heat transfer characteristics of the air - material drying situations. In the present work, various processing aids that improve the heat transfer in drying of granular material are reviewed. In addition, data from drying of acid casein, wheat and shelled corn were also resented.