(671a) Turbulence Damping Above the Cloud Height in Stirred Tanks with 20-30 Weight Percent Glass Beads: Data for Multiphase CFD Simulations
AIChE Annual Meeting
2021
2021 Annual Meeting
North American Mixing Forum
Experimental and Computational Investigations of Mixing Processes
Monday, November 15, 2021 - 12:30pm to 12:55pm
Poor mixing in the clear liquid layer above the cloud height has been reported by several
authors. This study uses LDV measurements to quantify turbulence above the
cloud using a liquid level of 1.5 T to remove the barrier of a free surface at H = T. A
D = T/3, down-pumping PBT was used at an off-bottom clearance of C = T/3. Three
slurries were tested at impeller speeds 0.8, 1, and 1.2Njs. The change in turbulence
was quantified using the normalized root mean square (RMS) of the fluctuating velocity
summed and averaged over each radial traverse. A significant difference between
the fluctuating values of the cloud height—minimum, average, and maximum—was
observed. The turbulence decays until the maximum cloud height. Beyond that, it
remains constant and near zero. The effects of both particle size and solids concentration
prove to be important.
Note: This paper was recently published in the AIChE Journal but has not previously been presented.
authors. This study uses LDV measurements to quantify turbulence above the
cloud using a liquid level of 1.5 T to remove the barrier of a free surface at H = T. A
D = T/3, down-pumping PBT was used at an off-bottom clearance of C = T/3. Three
slurries were tested at impeller speeds 0.8, 1, and 1.2Njs. The change in turbulence
was quantified using the normalized root mean square (RMS) of the fluctuating velocity
summed and averaged over each radial traverse. A significant difference between
the fluctuating values of the cloud height—minimum, average, and maximum—was
observed. The turbulence decays until the maximum cloud height. Beyond that, it
remains constant and near zero. The effects of both particle size and solids concentration
prove to be important.
Note: This paper was recently published in the AIChE Journal but has not previously been presented.