Measurement and Analysis of Drop Size in a Batch Rotor-Stator Mixer

Hydrodynamics of CNT dispersion in high shear dispersion mixers

“…The small scale turbulence structure that is related with the dispersed drop/particle size is likely isotropic, which means that the turbulent stress can be estimated by the isotropic turbulence theory with the energy cascade spectrum in the inertial subrange. The idea adopted in this work is that the eddy scales of the same as or smaller than the ultimate dispersed particle size influences the final dispersed state; the larger eddies will convect particle clusters (Calabrese et al, 2000). Then the turbulence stress is estimated simply by integrating the energy spectrum, E(k) = 1.5ε 2/3 k −5/3 , which is universally scaled with given turbulent energy disspation rate ε, over the relevant eddy length scales.…”

“…(1) describes CNT breakup in a laminar elongational flow, which is very different from turbulence breakup in homogenizers, where shear and pressure fluctuation should be taken into account. Typical approach in deriving turbulence dispersion models are presented in Kusters (1991) for particle clusters and Calabrese et al (2000) for droplets. In this work, we follow their approaches in high shear homogenizers, by substituting the expression in Eq.…”

“…Calabrese et al (2000) performed the drop size measurement in a rotor-stator device and the result has been correlated with a class of hydrodynamic models accounting for drop interaction with turbulence at various length scale. Utomo et al (2008) investigated flow characteristics of a rotor-stator mixer computationally and reported that about 70% of energy is dissipated near the mixing head and jet velocity scales with the rotor speed N, while the energy dissipation scales with N 3 .…”

Design and Implementation of Differential Agitators to Maximize Agitating Performance

“…A centrifugal agitator with a single impeller that can develop a differential pressure of more than 150 psi between the suction and the discharge is difficu lt and costly to design and construct. A mo re economical approach to developing high pressures with a single centrifugal agitator is to include mu ltiple impellers on a common shaft within the same ag itator casing [9]. Internal channels in the agitator casing route the discharge of one impeller to the suction of another impeller.…”

“…Internal channels in the agitator casing route the discharge of one impeller to the suction of another impeller. [9]. The impeller somet imes contains balancing holes that connect the space around the hub to the suction side of the impeller.…”