Thermodynamic Analysis in Bubbling Fluidized Bed Dryers With Spiral and Cone Angles

Abstract

Effective thermodynamic analysis is quite necessary for proper system design performance and optimization of system processes. Energy is concerned with the quantitative evaluation of system processes. Nonetheless, exergy gives a qualitative analysis of the system processes. The present investigation deals with the study of exergy and energy analysis of the paddy drying processes in two tapered fluidized bed dryers having the tapered angle 5 deg and 10 deg, respectively, and one cylindrical bubbling fluidized bed dryer. The energy utilization (EU) and energy utilization ratio (EUR) for various operating parameters such as inlet air velocity, mass of paddy, temperature, a spiral, and cone angle are investigated. Similarly, the exergetic efficiency and the rate of exergy destruction are also studied for the same operating parameters. The EU and EUR are found to have an increasing order when the inlet air velocity, temperature, and mass of paddy increase. The trend of EU and EUR also increases with an addition of a spiral inside a dryer. The increasing cone angle of the dryer has a similar impact on EU and EUR as that of other operating parameters. Similarly, exergy utilization and exergetic efficiency also show an increment with the rise in inlet air velocity, mass of paddy, cone angle of dryer, and temperature. The incorporation of a spiral inside a dryer improves exergy utilization and exergetic efficiency. Hence, the conical dryer with a higher cone angle is found to be the best option for drying.