Simulation of a stirring hydrodynamics of a two-component solution in the head reactor of the ammonium polyuranate precipitation cascade

Simulation of a stirring hydrodynamics of a two-component solution in the head reactor of the ammonium polyuranate precipitation cascade.

Khomyakov A. P., Ponizov A. V., Mordanov S. V., Naskina D. R., Khomyakova T. V., Lavrov A. S., Gushshamova V. N.

The paper shows the research results of the uranium sulfate solution and ammonium carbonate solution mixing processes in the JSC “Dalur” ammonium polyuranate precipitation cascade head reactor with the modernized mixing device. The research was performed using computational fluid dynamics methods in the “ANSYS CFD” software package using a mathematical model based on the Navier-Stokes equations in the multicomponent Manninen formulation, the standard k-ε turbulence model and the sliding mesh method.
For a stirrer speed of 180–1 020 rpm, the distributions of the velocities and the volume fractions of components in the head reactor of the ammonium polyuranate precipitation cascade were obtained. It was shown that the cascade head reactor mixing time is limited by the distribution duration of the ammonium carbonate solution volume fraction. It was found that the uniform distribution of the ammonium carbonate solution volume fraction in the head reactor takes 15–20 min, when the proposed modernized mixing device is used in the considered stirred speed range.
The steady-state path lines of the component’s mixture in the head reactor with the proposed modernized mixing device were observed under continuous operation mode. It was found that an intensive mixing throughout the reactor volume is typical for all the considered stirring regimes. It was demonstrated that the using of modernized mixing device will allow reducing the residence time for chemical agents in the head reactor and decreasing the ammonium carbonate consumption for the ammonium polyuranate precipitation. The further research directions were determined.

Keywords: ammonium polyuranate precipitation, mixing device, computational fluid dynamics.

Article language: Russian. Pp. 5–17. [in Russian]. DOI: 10.26277/SECNRS.2023.107.1.001.