396520 Residence Time Distribution Studies on a Rotary Calciner with Flights

Monday, November 17, 2014
Galleria Exhibit Hall (Hilton Atlanta)
Ingrid J. Paredes1, Heather N. Emady1, Benjamin J. Glasser2, Fernando J. Muzzio3, Alberto Cuitiņo4, William G. Borghard1,5, Bereket Yohannes4, Jean W. Beeckman5, Samia Ilias5, Paul Podsiadlo5, Joseph Baumgartner5 and George E. Jezek5, (1)Department of Chemical & Biochemical Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ, (2)Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, (3)Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ, (4)Department of Mechanical and Aerospace Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ, (5)ExxonMobil Research & Engineering, Annandale, NJ

Rotary calcination is a thermal treatment process poorly understood, yet commonly used in catalyst manufacturing. Problems arise particularly upon scale-up of the process from the laboratory and pilot plant scales to the manufacturing scale. Developing such fundamental understanding of rotary calcination can improve product quality and cut energy and material costs.  The two important indices for continuous calcination are: (1) in the axial direction, the residence time of the particles inside the calciner, and (2) in the radial direction, the characteristic time of calcination. This research seeks to provide a methodology for scale-up through understanding of the effects of calciner geometry, operating conditions and material properties on particle residence time and temperature distributions. To optimize calciner performance, the particle residence time must exceed the time required for heating and calcination.  For uniform treatment, the particles must also exhibit low axial dispersion. A combination of discrete element method (DEM) simulations and experiments are used to explore the influence of these competing timescales on scale-up. This poster focuses on the results of recent residence time and dispersion studies conducted on a pilot plant scale calciner. In the experiments, the influence of operating conditions and material properties on the mean residence time, hold up and axial dispersion in a pilot plant rotary calciner. It was observed that increasing the feed rate did not significantly affect the mean residence time, while increasing the calciner incline and rotary speed decreased mean residence time.


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