Investigation Of Particle-liquid Flow Characteristics In Stirred Tank Using Simultaneous PIV-PTV Velocimetry Technique

Solid-liquid suspension stirred reactor is widely used in chemical production process.The agitator can accelerate the mixing or separation of materials,enhance mass transfer and heat transfer,and fasten the chemical reaction.In recent years,there have been many researches on solid-liquid suspension reactors,but most of these researches have focused on the study of liquid flow characteristics in stirred tanks.There are few studies on particle dynamics.The study of particle dynamics helps us to design the reactor better and provides basic data for the design and optimization of the numerical simulation model.In this paper,simultaneous PIV-PTV velocimetry technique is used to realize the visualization of fluid flow in solid-liquid stirred reactor,and the particles are analyzed at high resolution.By mixing methyl silicone oil and phenyl silicone oil,the refractive index of the mixed silicone oil and borate silicate glass bead was matched.The highest particle volume fraction was 9%.By changing the solid holdup and phase angles,the effects of particle volume fraction and phase angles on the solid-liquid two-phase velocity field,root mean square fluctuant velocity and turbulent kinetic energy were explored.It is found that the presence of particles generally weakens the velocity and turbulent kinetic energy of the fluid,but when the solid content is 6%by volume,the velocity and turbulent kinetic energy of the liquid near the blade and the groove wall increase,which is attributed to the particle collision.Solid volume fraction has little effect on particle velocity.The turbulent kinetic energy of particles decreases as the solid volume fraction increases.When the phase angle is 30°,the solid-liquid slip velocity is the largest.The axial slip velocity is greater than the radial slip velocity.As the solid volume fraction increases,the solid-liquid slip velocity increases.