Abstract A novel supergravitational swirling-type quench box with multiple swirling flow structures was designed. In order to study the effects of operating conditions on the micromixing process, the cold model experiments were carried out based on the competitive and consecutive reaction between 1-naphthol and diazotized sulphanilic acid, and the segregation index was used to characterize the micromixing performance. The results showed that the segregation index decreased sharply with the increase of the gas flow rate, while increased with increase of the liquid flow rate. It indicated that the gas and liquid could be intimate contact in the new designed quench box, while the turbulence intensity and micromixing efficiency of the liquid could be notablely improved by driving effect of the gas phase. The relationship between segregation index and micromixing time was obtained according to the incorporation model. Under the experimental operating conditions of this work, the calculating micromixing time was 40-100 ms, which was far less than the average residence time and was of the same order of magnitude as the mechanicaly stirred tank, which illustrated that the supergravitational swirling-type quench box owned excellent micromixing performance.
