Using CFD to derive reduced order models for heat transfer in particle curtains

3-D Eulerian-Eulerian CFD is used to simulate convective heat transfer in free falling particle curtains. Total heat loss for curtaining particles is compared to heat loss for isolated single particles. Spherical silica particles with density of 2,634 kg/m(3) at 400 K (200 mu m, 400 mu m and 600 mu m) flow at approximately 0.041 kg/s to 0.2 kg/s through a narrow slot in a rectangular box (0.45 m x 0.9 m x 0.225 m) filled with ambient air. The slot sizes through which the particles enter the rectangular box were 10 to 80 mm wide. Modifying the slot size at 0.041 kg/s for 400 mu m particles can lead to 13% increases in rates of convective heat transfer per unit mass. A reduced order model was developed to predict the centreline temperatures of particles in the falling curtains. The drag coefficient in the ROM was varied to suit a range of particle sizes and mass flow rates.