Study on the pneumatic dispersion effect of powder based on lobed mixer

This study applies the lobed mixer to the field of powder pneumatic dispersion and compares the powder dispersion performance of a designed lobed mixer with that of an annular mixer having the same exit cross-sectional area. Numerical simulations of particle aggregation and breakage processes were conducted using the Two-Fluid Model coupled with the Population Balance Model. The Fluent software's User-Defined Function capability was utilized to customize the aggregation kernel function, and the homogeneous discretization method was employed to solve the population balance equation. The results indicate that, compared to the annular mixer, the average particle diameter at the computational domain outlet for the lobed mixer decreased by approximately 15.7%. Additionally, the rate of increase in average particle diameter along the flow direction is relatively stable for the annular mixer, whereas the lobed mixer exhibits a pronounced increase in particle diameter primarily in the vicinity of the lobed mixer exit. Moreover, the structural differences in the distribution of three key flow field parameters influencing the turbulent aggregation kernel function—particle-phase volume fraction, gas-phase turbulent dissipation rate, and particle-phase turbulent kinetic energy—are considered the primary cause of the observed differences in average particle diameter evolution along the flow direction.