Abstract:
Bubble column reactor is widely used in oxidation, hydrogenation, chlorination, etc., due to its simple structure, convenient operation, no moving parts, and good heat and mass transfer performance. However, the conventional bubble column reactors are currently difficult to meet the production requirements. The reinforcement of gas-liquid contact of bubble column reactor has been a new direction in the research of bubble column reactor. Some researches show that the packing set in bubble column reactor can reinforce the gas-liquid contact and thus improve the reaction rate. However, the hydrodynamics performance of packing set bubble column reactor and the influences of the structural parameter on its performances have not yet been explored. In this study, metal Pall rings were used as the internal component to investigate the gas-liquid contact condition in the bubble column reactor. The average gas holdup was measured by volume expansion method and the bubble size and bubble size distribution upon using different types of Pall rings were studied by high-speed camera technology. The results showed that
Φ25 Pall ring had the best bubble cutting ability, by which the bubble size distribution is confined within 3.00−6.00 mm. The Sauter mean diameter of bubbles increased with gas velocity and levelled off at high gas velocities. The average gas holdup of the bubble column reactor increased with the gas velocity, and the smaller the Pall ring size is, the larger the gas holdup can be achieved. The experimental data was used for nonlinear regression and the correlation of the gas holdup. Sauter mean diameter and gas-liquid specific surface area were obtained within the experimental gas velocity range. The calculated values agreed well with the experimental results.