Study of bubble dynamics in gas-solid fluidized beds using ultrashort echo time (UTE) magnetic resonance imaging (MRI)


Type
Article
Change log
Authors
Fabich, HT 
Sederman, AJ 
Holland, DJ 
Abstract

© 2017 Elsevier Ltd A narrow column, gas-solid fluidized bed was studied using ultrashort echo time (UTE) magnetic resonance imaging (MRI) for particles of diameter 0.44 mm, 0.72 mm, and 1.5 mm. UTE enables 1D and 2D images to be acquired of an individual bubble as it rises through the sample with higher spatial resolution than has previously been possible with MRI. One-dimensional images allow calculations of bubble rise velocity and bubble frequency. They also show leading-trailing bubble coalescence. Images of bubbles in the axial plane were obtained in 2D, with the location of images adjusted to track bubbles as they rise. These measurements were used to observe the wake region of a bubble, lateral drift as the bubble rises, and in-plane bubble coalescence. Images in the vertical plane were used to study the stability of a 1D perturbation in voidage. The perturbation collapsed rapidly with particles <1 mm in diameter, but for the 1.5 mm diameter particles the perturbation was often stable throughout the imaging region.

Description
Keywords
Fluidized bed, Magnetic resonance imaging, Ultrashort echo time, Bubble stability
Journal Title
Chemical Engineering Science
Conference Name
Journal ISSN
0009-2509
1873-4405
Volume Title
172
Publisher
Elsevier BV
Sponsorship
Engineering and Physical Sciences Research Council (EP/F047991/1)
Engineering and Physical Sciences Research Council (EP/K008218/1)
Engineering and Physical Sciences Research Council (EP/K039318/1)
EPSRC (EP/K008218/1, EP/F047991/1 and EP/K039318/1)