Convection drying process modeling and simulation study based on tomato

Abstract

Traditionally, temperature is considered as the most important factor in drying processes, and most of the drying processes are governed by temperature control. This study, mainly, focuses on the other two factors, humidity and air flow. The humidity in a dryer can be controlled by the change of exhaust air rate to the dryer. The humidity within the dryer can be held constant through the control of the recirculation rate using a proportional value. The air flow can be changed by fruit packing or dryer structure design. The air speed in laminar flow dryers relies on the fruit spacing to achieve the required air speed. This dependence can be removed through designing dryers that use 'turbulent flow'. Our simulation study shows that a dryer with such a control system can produce fruit that has super quality at a lower cost in a known time frame.