Intrusive probes in riser applications. Issue 12 (12th August 2017)

• Record Type: Journal Article
• Authors: Cocco, Ray A.; Karri, S.B. Reddy; Knowlton, Ted M.; Findlay, John; Gauthier, Thierry; Chew, Jia Wei; Hrenya, Christine M.
• Is Part Of: AIChE journal. Volume 63:Issue 12(2017)
• Page Start: 5361
• Page End: 5374
• Publication Date: 2017-08-12
• Subjects: intrusive probe -- fluidized bed -- fiber‐optic probe -- local hydrodynamics -- pitot tube; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; 660.28
• DOI: 10.1002/aic.15892
• Languages: English
• ISSNs: 0001-1541

Abstract

Abstract : Many of the probes used to understand hydrodynamics in circulating fluidized bed risers intrude into the environment they are measuring, although assumptions are typically asserted that the intrusive probes do not affect the data collected. This could be a poor assumption in some cases and conditions. We found that intrusive fiber‐optic probe measurements consistently mis‐predicted the solids concentration compared to the nonintrusive pressure drop measurements outside the fully developed flow region of a riser containing fluid catalytic cracking catalyst or glass bead particles. The discrepancy was sensitive to superficial gas velocity, solid circulation rate, probe position, and flow direction. Barracuda VR™ computational fluid dynamics simulations confirmed this, and indicated that particle momentum was lost at the leading edge of the probe and particles were spilling over to the probe tip. Accordingly, new probe designs were proposed to mitigate the intrusiveness of a fiber‐optic probe for more accurate characterization. © 2017 American Institute of Chemical Engineers AIChE J, 63: 5361–5374, 2017