Heat Transfer Enhancement Due to Cold Cap Motion from Bubbling in a Waste Glass Melter

Abstract

In this study, a computational fluid dynamics (CFD) model was developed to model the motion of a solid cold cap in a waste glass melter. Forced convection bubblers at the base of the melter release air into the molten glass, which forms large bubbles that travel upward to the cold cap and augment heat transfer from the glass to the cold cap. The CFD model employs the Navier–Stokes equations to solve for the fluctuating flowfield using a rigid body motion dynamic fluid body interaction module. This allows for movement of the floating body in response to the bubbling forces calculated at each time-step. The heat flux delivered to the cold cap by the convective bubbling is studied as a function of the normalized bubbling rate. Results for the moving cold cap are compared with the computed heat flux trends for a stationary cold cap. The heat flux delivered to the cold cap from the molten glass is 25% higher for the case with the moving cold cap as opposed to a stationary cold cap.