Experimental Characterization of Gas-Liquid Flows in Splitting Distributor for Parallel Micro-Channels

The present work is focused on experimental investigations of gas-liquid flows in T-junction splitting distributor for parallel micro-channels. The tree type T-junction splitting distributor was designed with four successive T-junctions (T-1, T-2, T-3 and T-4) that are linked in series to split a single main channel into four parallel channels. The design strategy was adopted from Adamson et al. [1], Hoang et al. [2], and modified with a combination of micro and milli channel dimensions and reduction in width of the successive blocks by a factor of 2(0.5) to ensure the flow uniformity in terms of constant relative lengths (L-bubble/slug/W-channel) of bubbles/slugs in all the blocks. Experiments were performed to study the effect of Q(oil) (=3, 6, 8, 10, 12 and 16 ml/min) at fixed Q(air) (=3 ml/min) on formation dynamics of bubbles/slugs at 1st T-junction and splitting mechanisms of bubbles/slugs at the successive T-junctions, the corresponding relative lengths of bubbles/slugs and flow regimes. The results obtained from the present work showed that, followed by formation of parent gas slug at T-1 the splitting of gas slug occurred at the successive T-junctions (T-2, T-3 and T-4). Three types of splitting mechanisms were observed such as obstructed (Q(oil) = 3, 6, 8, 10 ml/min; 0.0023 <= CaBlock-I <= 0.0050), partially obstructed (Q(oil) = 12 ml/min; CaBlock-I = 0.00585) and non-obstructed (Q(oil) = 16 ml/min; CaBlock-I = 0.0074). It was observed that asymmetry of the splitting at the successive T-junctions was reduced for Q(oil) >= 10 ml/min (CaBlock-I >= 0.0050). No splitting of bubble was observed for Q(oil) > 16 ml/min. However, it was also found that the proposed design strategy of splitting distributor for parallel micro-channels yields an almost constant relative lengths of bubbles/slugs (flow uniformity) in all the blocks for Q(oil) >= 8 ml/min.