Experimental evaluation of hydrodynamics and tube-to-bed heat transfer of fluidized Ilmenite ore particles at elevated pressures

The minimum fluidization velocity (U-mf), bubble size characteristics, and tube-to-bed heat transfer coefficient (h(c)) of ilmenite particles are investigated at pressures up to 2000 kPa. The U-mf was found to decrease with pressure for d(sv) >= 236 mu m and remain constant for d(sv) <= 109 mu m. U-mf was compared to various Wen and Yu type correlations (Re-mf = root C-1(2) + C2Ar-C-1) with the Saxena & Vogel (1977) constants resulting in the best fit (AARD = 10.5%) for d(sv) <= 109 mu m and the Chitester et al. (1984) constants resulting in the best fit (AARD = 6.4%) for d(sv) >= 236 mu m. Pressure marginally effected bubble size relative to gas velocity, with the data fitting the Mori & Wen (1975) correlation best (AARD = 26.4%). The tube-to-bed heat transfer coefficient experienced a maximum with increasing gas velocity and marginally increased with pressure. The Molerus et al. (1995) correlation matched the atmospheric heat transfer data. (C) 2020 Published by Elsevier B.V.