Flow patterns of solids in a two-dimensional spouted bed with draft plates: PIV measurement and DEM simulations

Particle flow behaviors in a two-dimensional spouted bed (2DSB) with draft plates were studied using both the particle image velocimetry (PIV) and the combined technique of discrete element method and fluid dynamic computation (DEM-CFD) while considering the gas turbulence effect. The bed consisted of a rectangular column, 152 mm wide and 15 mm deep, a conical section with an included 60° angle and two draft plates with a distance of 15 mm. Images of particle flow were recorded by a high speed CCD camera and analyzed using a self-developed PIV algorithm to obtain a time-averaged particle velocity field. Experiments predict that the addition of draft plates not only makes the streamline of particles in the annulus steeper, but the velocity magnitude is made smaller as well. DEM results predict well the longitudinal profile of the particle vertical velocity along the bed centerline, especially during the rapid acceleration stage at the lower part of the spout. Finally, the distributions of drag forces and net forces are introduced in this paper to explain the particle velocity profiles by PIV measurement.