Abstract In order to investigate the flow pattern of materials in the reactor and provide information for reactor optimization, particle image velocimetry (PIV) was used to carefully measure the turbulent flow field of particles in a liquid injected gas-solid fluidized bed. The velocity of particles in the sidewall area and central area was statistically analyzed, the proper orthogonal decomposition (POD) was used to decompose and reconstruct the flow field, the coherent structure was extracted and the effect of the injected liquid on the turbulent flow field was analyzed. The statistical results of velocity showed that the particle movement became more intense when small amount of liquid was injected, and the velocity fluctuation of particles in the sidewall area was larger than that in the center region because of the side wall effect. The spatial modal diagrams obtained by POD showed that the large-scale coherent structure mainly appeared in the sidewall area, and the coherent structure was corrugated and developed to the small-scale structure with the gradual addition of liquids. Therefore, the injection of a small amount of liquid promotes the particle movement in the fluidized bed, which is beneficial to improve the efficiency of the reactor.
