Unbaffled mesoscale reactor coupled oscillatory flow-enhanced liquid–solid two–phase flow

Unbaffled U-shaped mesoscale oscillatory flow reactors (meso-OFRs) were developed to prevent solid deposition and prepare uniform barium sulfate (BaSO4) nanoparticles with environmental protection function. The results showed that the oscillation significantly reduced granular deposition; the greater the intensity of the oscillation, the faster it reached uniformity, and the less likely the granules were to be deposited. These results can be explained by the formation of a larger vortex size, which can strengthen the turbulent mixing of fluid in the reactor, promote the interaction and forced mixing between the liquid phase and solid particles, enhance the internal shear stress of the fluid, and contribute to the secondary suspension of solid particles and the disintegration of particle agglomeration. The prepared BaSO4 nanoparticles with oscillation were smaller in size and lower in pressure drop than those produced without oscillation, which conclusively illustrated that oscillation effectively prevented channel deposition and clogging. [Display omitted] •The meso-OFR could prevent solid deposition and prepare uniform nanoparticles.•The formation of vortex contributed to the secondary suspension of solid particles.•The prepared BaSO4 nanoparticles were smaller in size and lower in pressure drop.