Comparative Analysis and Performance Improvement of Modified Forced Convection Solar Dryer with Recirculation of Air

The paper presents a study using solar dryer induced with the forced draught design in combination with closed loop circulation of air and also development of lens and analyzing the performance of the dryer for parching edible fruit in varying climatic conditions of Coimbatore, India. The process comprises of components viz., a chamber for drying, solar air heater in flat plate design with the circulation tubes and a programmable microcontroller. The air flow rate for the process has been determined as 0.2058 kg/s. The usage of solar dryer for drying the edible fruit is found to be effective since it reduces the moisture content from 79% according to wet basis and the finalized wet content in the edible fruit is only around 9.65% in a time period of 24 hours. The efficiency of the dryer is to be averaged around 22%. The moisture specification rate is concluded to be about 0.87 kg/kWh. Establishing a model of modified solar dryer is the main objective of the work.