K. Dewsbury et al., Hydrodynamic characteristics of free rise of light solid particles and gasbubbles in non-Newtonian liquids, CHEM ENG SC, 54(21), 1999, pp. 4825-4830
The main objective of this study was to determine the primary parameters af
fecting the rise of gas bubbles and light solid particles in non-Newtonian
(pseudoplastic) liquids. The results obtained for the rise of light solid p
articles were used to explain the behavior of rising gas bubbles. These res
ults were also compared to that of free-falling heavy particles. The main p
arameters studied were the drag coefficient, trajectory of rise, and termin
al velocity as a function of the shape and volume of gas bubbles and solid
particles, and the rheological properties of the non-Newtonian (pseudoplast
ic) liquid. It was determined that the most effective method for doing this
was with a movable video camera unit. It was discovered that freely rising
light solid particles have similar behavior to gas bubbles for a wide rang
e of Reynolds numbers. This indicated that the hydrodynamics of freely risi
ng light particles could be used to describe the behavior of gas bubbles. T
he comparison of the behavior of light solid particles and gas bubbles allo
wed us to determine the effect of the internal circulation of a gas bubble
on the hydrodynamics of its rise. A new correlation was proposed to predict
the drag coefficient and terminal velocity of gas bubbles in non-Newtonian
(pseudoplastic) solutions. (C) 1999 Elsevier Science Ltd. All rights reser
ved.