The nozzle structure has an important influence on the mixing and mass transfer performance of the jet bubbling reactor. In this paper

air-water is used as the simulation medium

and the double-probe conductivity probe

electrolyte tracer method and dynamic dissolved oxygen method are used to compare the bubble size distribution in the jet bubbling reactor with the reduced diameter circular nozzle and the rotary triangular nozzle. The results show that the variation rules of the average gas holdup

the liquid mixing time and the liquid volumetric mass transfer coefficient with the increase of the superficial gas velocity and the liquid jet Reynolds number in the jet bubbling reactors with two kinds of nozzles are the same. Compared with the case with necking circular nozzle

the bubble size is smaller

the average gas holdup is higher and the mixing time is shorter in the case with twisted triangular nozzle. The nozzle structure has little influence on the gas-liquid mass transfer coefficient when the gas input power accounts for more than 20% of the total input power. However

the gas-liquid mass transfer performance of the twisted triangular nozzle is better than that of the necking circular nozzle when the gas input power accounts for less than 20% of the total input power. The research results can provide theoretical guidance for the optimization of the nozzle structure in the industrial jet bubbling reactor.