Performance and Mixing Characterization of a New Type of Venturi Reactor for Hydrazine Hydrate Production

In this paper, a novel venturi jet reactor is innovatively proposed for the process of hydrazine hydrate production using the urea method. In order to investigate the performance of this reactor in depth, we used the computational fluid dynamics method to optimize the design of the structure of the new venturi jet reactor based on the flow field condition, the degree of mixing uniformity, and the efficiency of the reactor using the component transport model. The results showed that the moderate increase of the distance of mixing tube to nozzle and nozzle diameter seven could help to improve the efficiency of the jet reactor; however, in terms of the mixing effect, the increase of the distance of mixing tube to nozzle led to the mixing effect to be enhanced and then weakened, while the increase in the nozzle diameter was not conducive to the full mixing of the two fluids. In addition, the effects of ratio of throat length to diameter and constriction angle on the efficiency of the jet reactor showed nonlinear characteristics, and the optimal values existed in the study range. Based on the above analysis, this paper determines the optimal range of structural parameters, i.e., the distance of mixing tube to nozzle of 7–13 mm, the nozzle outlet diameter of 5–7 mm, the ratio of throat length to diameter of 3–5, and the constriction angle of 30–40°, and the study provides guidance for the industrial application of the venturi jet reactor.