Age distribution and the degree of mixing in continuous flow stirred tank reactors

Flow field and homogenization time assessment in continuously-fed stirred tanks

“…The authors estimated characteristic fluid flow malfunctions such as active mixed volume and short-circuiting. Liu (2012) used CFD simulation of CSTR with several inlet-outlet configurations to show the effectiveness of a novel method for quantifying the age distribution (and therefore RTD) in continuously fed stirred vessels, showing that poor feeding geometry may well lead to high short-circuiting. Torré et al (2008) used CFD and experimental fluid M a n u s c r i p t visualization techniques to investigate the rapid injection of a jet through the free surface of a partially baffled stirred vessel.…”

Development of a submerged anaerobic membrane bioreactor for concurrent extraction of volatile fatty acids and biohydrogen production

“…These were compared to mixing time measurements in the presence of the recirculation loop. The mixing time (t m ) and mean circulation (t c ) times in the stirred tank were extracted from the experimental curves of tracer concentration vs. time as a function of recirculation flow rate and impeller rotation speed, as in Liu (2012). Then, RTD analysis was carried out in the membrane fiber bundle under continuous flow conditions, without and with permeate extraction, as a function of the impeller rotation speed in the tank, the circulation flow rate and the speed of the withdrawal pump.…”

Laboratory and Computational Fluid Dynamics Investigation of Homogenization in a Tank Stirred by External Pump

“…By analyzing the deviation of the distribution curve of the investigated reactor from the ideal ones, some non-ideal mixing properties can be recognized. RTD method shows the existence of dead zones and bypasses, but the sizes and locations of them cannot be determined [13]. Other methods are yet to be used thorough characterization of dead zones, for example, the Computational Fluid Dynamics (CFD), which is an effective tool to gather information about mixing.…”