ABSTRACT
Micromixers with different shapes of barriers including cylindrical, semi-cylindrical, conical, and semi-conical were fabricated using 3D printer. Water (Alizarin Red S) + Aliquat 336 + 1-octanol system was chosen for analyzing mass transfer. Computational fluid dynamics analysis showed that the improvement of flow patterns in the case of cylindrical barrier was higher than that in other micromixers. The extraction efficiency using cylindrical barriers was 23.7–83.7% higher than that of the plain one. Performance ratio criterion was used for design selection. The highest performance ratios with the values of 1.04–1.65 were obtained in the microchannel with six conical barriers.
Nomenclature
A | = | Cross-sectional area of the microchannel (m2). |
C | = | Concentration of Alizarin Red S (mg/L). |
CM | = | Cylindrical barrier mixing channel. |
CoM | = | Conical barrier mixing channel. |
D | = | Microchannel diameter (m). |
E | = | Extraction efficiency (–). |
F | = | Overall mass transfer coefficient (mol/m2.s). |
f | = | Friction factor (–) |
g | = | Gravity (m/s2) |
hf | = | Friction loss (m) |
hl | = | Local loss (m) |
kl | = | Local loss coefficient (–) |
kLa | = | Volumetric mass transfer coefficient (1/s). |
L | = | Mixing channel length (m). |
PM | = | Plain mixing channel. |
Pp | = | Pumping power (W) |
ΔP | = | Pressure drop (mbar) |
Q | = | Total volumetric flow rate (m3/s). |
SCM | = | Semi-cylindrical barrier mixing channel. |
SCoM | = | Semi-conical barrier mixing channel. |
Sh | = | Sherwood number (–) |
St | = | Stanton number (–) |
tM | = | Residence time of two-phase mixture (s). |
UM | = | Superficial velocity of two immiscible phases (m/s). |
V | = | Total volume of mixing channel (m3). |
x | = | Volume fraction of each phase (m3/s). |
Greek letter
ρ | = | Density (kg/m3). |
η | = | Performance ratio criterion (–). |
µ | = | Dynamic viscosity |
Subscripts
aq | = | Aqueous phase |
in | = | Inlet |
M | = | Mixture of the liquid–liquid two phases |
org | = | Organic phase |
out | = | Outlet |
* | = | Equilibrium |