Liquid nitrogen freezing method for exploring the mixing characteristics of liquid/liquid heterogeneous in outer packing cavity of Impinging Stream-Rotating Packed Bed

Impinging Stream-Rotating Packed Bed (IS-RPB) is a reactor developed to strengthen the mass and heat transfer in liquid-liquid mixing processes. The impingement, packing and packing edge cavity zones are crucial features in which mass transfer is highly relevant. In a heterogeneous system composed of an oleic and an aqueous phase, understanding the droplet diameter distribution in the packing edge cavity of an IS-RPB is a key to modeling and evaluating its mass transfer performance. However, such pattern is still unclear. In this work, the flow pattern of the oleic and aqueous phases, including the transitions of fluid ligament flow and droplet flow, and the oil droplet in mixing of oleic and aqueous phases in the packing cavity were studied under different experimental conditions by using a liquid nitrogen freezing method and studied by Optical microscopy. The results showed that droplet determined by this method has good reproducibility with a deviation within 8.4 %, and with a detection limit below 1 mu m.