The Effect of System Pressure on Gas-Liquid Slug Flow in a Microchannel

Characteristics of gas-liquid two-phase flow under elevated pressures up to 3.0 MPa in a microchannel are investigated to provide the guidance for microreactor designs relevant to industrial application. The results indicate that a strong leakage flow through the channel corners occurs although the gas bubbles block the channel. With a simplified estimation, the leakage flow is shown to increase with an increase in pressure, leading to a bubble formation shifting from transition regime to squeezing regime. During the formation process, the two-phase dynamic interaction at the T-junction entrance would have a significant influence on the flow in the main channel as the moving velocity of generated bubbles varies periodically with the formation cycle. Other characteristics such as bubble formation frequency, bubble and slug lengths, bubble velocities, gas hold-up, and the specific surface area are also discussed under different system pressures. © 2013 American Institute of Chemical Engineers.