Modeling the Impact of Particle Diameter on the Conductive Heating Performance of Rotary Equipment

Rotary equipment has been used widely in the processing of particulates for the last century, but low thermal efficiency and poor effluent uniformity continue to plague its performance. Consequently, these technologies contribute largely to modern energy waste, environmental pollution, and price inflation of products dependent on particulates in their manufacture. Large industries like pharmaceuticals and oil are impacted, yet minimal research has been conducted into optimizing the equipment because of costs associated with process shut-downs necessary to enable study. Recent works bypassed this constraint with simulations and scaled-down replicates to observe impact of common design parameters, fill level and rotation speed, on heating. This thesis supplanted these studies by investigating particle diameter as a control parameter to optimize heating. The thesis investigated methodologies to study a stainless-steel rotary drum model facilitating the conductive heating of a silica bed by external heat guns. Diameter was varied 2-4 mm at controlled fill levels and rotation speeds, and radial temperature profiles were measured with thermocouples. Heating performance was evaluated for efficiency and uniformity; the former by analyzing thermal time constants and average temperature progression across 70 minutes of operation, and the latter with corresponding radial temperature variances. It was theorized that the direct influence of size on transport properties would implicate an inverse correlation between diameter and performance, but results demonstrated no significance. The apparatus and methodology were still under development, so results were preliminary. From results, the study proposed setup modifications to refine results and future directions to guide follow-up research.