Gas holdup and liquid velocity distributions in the up flow jet-loop reactor

Model-Based Investigation of the Interaction of Gas-Consuming Reactions and Internal Circulation Flow within Jet Loop Reactors

Jet loop reactors are standard multiphase reactors used in chemical, biological and environmental processes. The strong liquid jet provided by a nozzle enforces both internal circulation of liquid and gas as well as entrainment and dispersion of the gas phase. We present a one-dimensional compartment model based on a momentum balance that describes the internal circulation of gas and liquid phase in the jet loop reactor. This model considers the influence of local variations of the gas volume fraction on the internal circulation. These local variations can be caused by coalescence of gas bubbles, additional gas-feeding points and gas consumption or production. In this work, we applied the model to study the influence of a gas-consuming reaction on the internal circulation. In a comprehensive sensitivity analysis, the interaction of different parameters such as rate of reaction, power input through the nozzle, gas holdup, reactor geometry, and circulation rate were investigated. The results show that gas consumption can have a significant impact on internal circulation. Industrially relevant operating conditions have even been found where the internal circulation comes to a complete standstill.

Experimental Study on Bubble Size Distribution in Gas-Liquid Reversed Jet Loop Reactor

Bubble size distribution (BSD) is important for gas-liquid jet loop reactor (JLR)’s mass transfer performance of inter-phases. A self-designed reversed JLR was investigated with air-water system on the BSD. The CCD camera of particle imaging velocimetry (PIV) system and image processing technique were used to obtain the reliable photo. The influences of four parameters, gas phase flow rate, liquid phase flow rate, draft tube diameter and ejector mounting position, on the BSD were studied in detail. The results showed that the local BSD is accordance with log-normal distribution under the experimental conditions and the average diameter and BSD range increase with the increase of the gas phase flow rate, and decrease with the increase of the liquid phase flow rate, the downward movement of the nozzle installation position and the increase of the diameter of the draft tube.