Enhancement of Drying of Food Products with Slot Jet Reattachment Nozzles in a Convective Oven with a Moving Belt

Abstract

Drying is one of the most energy-intensive unit operation in industrial applications. The energy intensity is due to the inherent inefficiency of utilizing hot air as the drying medium and high latent heat of vaporization. Slot jet (SJ) and perforated nozzles are extensively used in industrial applications as the most effective techniques in drying sections. Such nozzle configurations are greatly popular due to generating high transport characteristics however, a vast amount of energy would be wasted. It is therefore essential to come up with an improved design of such nozzles. Slot jet reattachment (SJR) nozzle could be an approach to address this issue and make the convective drying process more efficient.In this paper, the drying performance of SJR nozzles with an exit angle of +45° over a moving belt inside an industrial oven is experimentally investigated. The results are compared to those of perforated plates based on the identical fluid flow power criterion. The experimental results indicate up to 17.3% enhancement in drying rate of potato chip samples using SJR nozzles.