A simple flow device for enhanced mass transfer in reduced dimensions

• 90° bend promotes slugging in two phase flow.
• This phenomenon significantly improves mass transfer characteristics.
• Multiple bend has higher mass transfer rates than a single bend and helical coil.
• Addition of multiple bends enhances transport process at the cost of pressure drop.
• Multiple bends in series is a PI device for method aseptic bio-processes.

The present study proposes a device for process intensification for liquid–liquid flow systems in millimeter size conduits. This is accomplished by incorporating a 90° bend such that the flow is initially horizontal and then in downward direction. The device intensifies mass transfer controlled processes by enhancing the range of Taylor regime and decreasing the range of parallel flow, both contributing positively to enhanced mass transfer as compared to straight conduits. The proposed device has been numbered up by incorporating multiple bends connecting short horizontal sections to vertical up and downflow sections. This system is noted to be more effective than a helical coil which is a commonly used process intensification device in practical applications. The effectiveness has been quantified by considering the (a) overall volumetric mass transfer coefficient, (b) extraction efficiency and (c) energy dissipation parameter.