Liquid–liquid microflows in micro-sieve dispersion devices with dual pore size

Abstract

Here we present the liquid-liquid microflows and dispersion rules in micro-sieve devices with two different sized pores. The flow pattern, flux distribution and droplet size were investigated to discuss the effect of pore size deviation. Three flow patterns including dripping flow from a single active pore, dripping-dripping flow and dripping-jetting flow from two active pores were identified. A modified active pore model based on a pressure drop balance has been established. The model can predict the transition from a single active pore flow regime to a two active pore flow regime very well. In the latter regime, interactions between the small and large pores can result in dripping-dripping flow at low trans-pore flux and dripping-jetting flow at high trans-pore flux. Controlling the flow pattern in dripping-dripping flow is favorable to decreasing droplet polydispersity.

Generating Gas‐Liquid‐Liquid Three‐Phase Microflows in a Cross‐Junction Microchannel Device

“…This relation also works in the gas-liquid-liquid three-phase systems just by changing the formulas of phase ratio and capillary number as indicated in Eq. (15). Fig.…”

“…(13) and (15) and the number ratio n f actually reflects the ratio of bubble and droplet generation frequencies, n f equals to f W */f G +1. (13) and (15) and the number ratio n f actually reflects the ratio of bubble and droplet generation frequencies, n f equals to f W */f G +1.…”

“…Since the bubble generation frequencies are easily calculated using Eqs. (13) and (15) and the number ratio n f actually reflects the ratio of bubble and droplet generation frequencies, n f equals to f W */f G +1. The experimental and calculated average droplet volumes are given in Fig.…”

“…Several generation modes of bubbles and droplets (squeezing, dripping, jetting, etc.) in the T-junction [12], flow focusing [13], coaxial [14] and some other modified microchannel devices [15,16] have been extensively discussed. The relations between bubbles/droplet generation manners, twophase flow pattern, and bubbles/droplet size laws have been preliminarily defined, based on the fundamental force analysis at microscale, e.g., the competition between viscous force, inertia force, interfacial force, etc.…”