Design & construction of a clay based evaporative cooler for fruits.

Abstract

A clay based evaporative cooling system was designed and constructed to increase the shelf' life of stored fruits. The evaporative cooler was tasted and evaluated using three different fruits that is to say bananas, apples and mangoes. The equipment operates on the principle of evaporative cooling this cooler was made up of galvanized steel as a cooling chamber because of its features of corrosion resistance and high thermal conductivity, the surface was made up of clay because of its properties of how porosity, low heat conductivity and its availability and lastly sand was used as the cooling pad because of its high porosity and it’s not disintegrating in water. The water reservoir was placed on top of the cooling chamber so as to provide the head for water to flow into the sand by gravity. From the performance evaluation of the prototype, it was found that the system has a minimum efficiency of 75% and that's during the morning hours and the maximum. efficiency of 86% obtained in afternoon hours. After analysing the percentage mass loss of the fruits, it was found out that the cooler works best with mangoes followed by bananas.