Performance study of hybrid solar dryer for cassava starch

Abstract

An experiment has been performed to study the performance of hybrid solar dryer for cassava starch. This paper introduces a drying method in which solar dryer is combined with Liquefied Petroleum Gas as an auxiliary heater to support the drying process. Drying experiment was carried out from 10.00 to 13.00 with the dryer temperature of 40, 50, and 60 °C. The profiles of temperature, relative humidity, and solar intensity were very dependent of weather condition, geographical condition and location, and measurement time. Only the final moisture content from drying at 60 °C that could satisfy the maximum limit of cassava starch’s moisture content. It is found that higher temperature will lead to faster and more effective drying. The fastest moisture reduction occurred at the first tray, followed by the second and the third tray. The value of drying rate was high when the moisture content is still high, then gradually decreased as moisture content decreased. In this drying process, the constant rate period occurred very quickly, namely during the initial phase of the drying process. The drying process of cassava starch mostly happens in the falling rate period. The highest value of effectivity factor was recorded at 11.00, with the highest value of 6.4