Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

A computational fluid dynamics (CFD) model of the gas flow in a modified triple pass rotary drum dryer was developed using the renormalization-group (RNG) k- method. The geometric model of the dryer-separator was meshed with Tet / Hybrid elements. The results simulated showed that turbulence is the basic flow pattern in both the middle and the outer drums, and the gas velocity varies diminishingly from the inner to the outer drum. There exist two distinct turbulent zones at the U-turn areas where material blocks probably occur. Furthermore, there are two obvious vortices near the bottom wall of the middle drum, which is harmful to the continuity and separation of the feed streams. On the other hand, it is possible for material s to be dragged across the exit but not be discharged out. Several improving proposals for the dryer-separator were suggested based on the CFD simulation results with some practical conditions considered.