Design and Fabrication of Pneumatic Charcoal Kiln Drying Characteristics and Residence Temperature for Cat Fish Smoking

Drying is one of the essential unit operations performed to increase the shelf life of agricultural or horticultural produce and it is one of the most practical methods of preserving food and the quality of agricultural produce [1]. Traditionally, fish food produce are dried by spreading in open sun in thin layer and smoking using wood. Though this method is economical and simple, it has the draw backs like; no control over the rate of drying, non-uniform drying, chances of deterioration due to exposure of products against rain, dust, storm, birds, rodents, insects and pests which results in poor quality of dried products . Whereas, kiln pneumatic drying system leads to fast rate of smokedrying and exposure of products against rain, dust, storm, birds, rodents, insects and pests may obviously be avoided. Against this, open sun drying and smoke processing drying requires longer drying time and product quality are however difficult to control because of inadequate drying, high moisture, fungal growth and encroachment of insects, birds and rodents, as well as economy of space [1]. Drying is usually conducted by vaporizing water in the product Fellow 1988.Thus; the latent heat of vaporization must be supplied. Airflow is also required to remove the vapor away from the product. The lower the humidity of hot air supplied to the drying chamber, the better the drying rate, as the less humid air can carry more moisture from the product surface than the more humid air. Generally, increasing the temperature and velocity shortens the drying time hence pneumatic processing. For heatsensitive products, such as fish food and pharmaceutical products, high temperature decreases product quality. In this case, drying at low temperature and humidity is required to maintain the fresh color of the product using the desiccant system [1].