High efficiency separation of fine coke powders by the novel jet-swirl scrubber: Characteristics and mechanisms

Abstract

The deep removal of fine coke powders is an urgent need and remains a great challenge for the stable operation of the delayed coke system. Herein, a novel jet-swirl scrubber was developed. A combined approach utilizing CFD and DPM was employed to investigate the mechanism of droplet fragmentation. The results indicated that droplets underwent two stages of fragmentation in the convergent and throat sections under the influence of turbulent vortex structures. This leaded to a rapid reduction in droplet size and an effective dispersion. Thorough mixing with the gas phase occurred in the divergent section, facilitating enhanced capture of coke powders. Cold model experiments were conducted to examine the relationship between droplet size, coke powders capture efficiency, and gas-liquid separation efficiency. Under the condition of optimized critical droplet size 0.106 mm by adjusting the flow rate, the removal efficient of coke powders was up to 99.57 %. This work provides valuable technical support for further development and process optimization of the decoking powder unit in delayed coking system.