Solar drying cabinet
Drying is the oldest method of food preservation. There are several popular methods of drying such as solar drying, hot air drying and freeze dried. Solar drying is a popular and very inexpensive method. Energy source is solar heat gain without cost. The sun drying is a traditional sun drying, using solar energy to dry meat, fish, vegetables and fruits. Although, solar drying is cheap and easy method but there is major disadvantage is contamination of the products by dust, birds, insects and microorganism which directly affect quality and consumer acceptance. From this reason, there is the development of dryer by using cabinet drying electric power sources which high costs and auxiliary energy.
Principle of Operation
The process of dehydration consists of removal of moisture from the food by heat, usually in the presence of a controlled flow of air. The solar rays enter the cabinet through the cover material. When reaching the solar collector, solar energy was absorbed by black absorber within collector and then they are converted into heat energy raising the temperature inside approximately 60°C. The heat energy is transferred to the food to be dried. The heated food gives out water vapour and dries up. Gradually the heated moist air goes up and leaves the drying. Cold dry air enters the drying chamber through the air inlet.
