Study of Phase Splitting at a Micro-T-Junction

Small T-junctions are frequently applied in various devices, such as microreactors and compact heat exchangers. However, when a gas-liquid two-phase flow passes through a T-junction, uneven distribution of the phases will take place among the branching channels, which can cause reductions in both thermal and fluid-dynamic performances. An experiment has been carried out to study the transient behavior of water-nitrogen slug flow through a horizontal T-junction with square cross section (500m x 500m). It is observed that the distribution of liquid and gas at the inlet is changed with the gas taken off from the branch side. The merge of liquid slugs at the inlet occurs frequently at high gas taken off due to the decrease of slug velocity. At median gas taken off in the branch side, the system is highly unstable owing to the easier change of gas acceleration. However, the liquid split is not dramatically influenced by a wide range of values of gas taken off but depends more on the liquid superficial velocity. When the mixture velocity in the main branch is lower than the liquid superficial velocity, the liquid rapidly flow back from the main branch to the side branch.