In this work

by establishing a three-dimensional physical model of a 1000-ton industrial multi-jet combustion reactor

a hexahedral structured grid was used to discretize the model. Combined with realizable

k–ε

model

eddy-dissipation-concept

discrete-ordinate radiation model

hydrogen 19-step detailed reaction mechanism

air age user-defined-function

velocity field

temperature field

concentration field and gas arrival time in the reactor were numerically simulated. The Euler–Lagrange method combined with the discrete-phase-model was used to reveal the flow characteristics of particles in the reactor

and based on this

the effects of the reactor aspect ratios

central jet gas velocity and particle size on the flow field characteristics and particle back-mixing degree in the reactor were investigated. The results show that with the decrease of aspect ratio in the combustion reactors

the velocity and temperature attenuation in the reactor are intensified

the vortex phenomenon is aggravated

and the residence time distribution of nanoparticles is more dispersed. With the increase in the central jet gas velocities in reactors

the vortex lengthens along the axis

the turbulence inten

sity increases

and the residence time of particles decreases. The back-mixing degree and residence time of particles in the reactor also decrease with the increase in particle size. The simulation results can provide reference for the structural regulation of nanoparticles and the structural design of combustion reactor in the process of gas combustion synthesis.