Flow, Heat Transfer and Particle Drying Characteristics in Confined Opposing Turbulent Jets: a Numerical Study

ABSTRACT

Impinging stream contactors provide a novel configuration for drying and/or gas/solid chemical reactions involving particulates. pastes or suspensions which can be dispersed in a flowing gas stream. Essentially they consist of one or more highly turbulent “ impingement ” zones formed by normal collision of two confined opposing jets in a channel or duct. Little information exists in the current literature on the flow and thermal characteristics of such flows. The objective of this paper is to present computational fluid dynamic predictions for confined two-dimensional opposing turbulent jets over a range of nozzle-to-nozzle separations and jet Reynolds numbers and superheated steam drying of panicles in such contactors. The standard k-E model is used to close the governing conservation equations. Some results on the prediction of single particle trajectories and drying in such flows are presented. Predictions are performed in two distinct pans. In the first part a hybrid. finite volume method based on the “SIMPLEC” algorithm is used to solve the momentum and energy equations and in the

Keywords and Phrases:

• k-E model
• Lagrangian modeling
• impinging streams
• panicle trajectory
• residence time
• drying