| 초록 |
Layer inversion in gas-liquid-solid fluidized beds with binary solids was examined in a semi-acrylic column of 1.8 m height and 0.21 m inner diameter. Binary solid combinations were composed of polymer beads (PB, dp = 3.3 mm, ρs = 1,280 kg/m3) and glass beads (GB, dp = 0.385 mm, ρs = 2,500 kg/m3). Various volumetric ratios (PB:GB = 0.67:0.33, 0.6:0.4, 0.5:0.5, 0.4:0.6, 0.33:0.67) were used to examine superficial liquid velocities, Ul = 21.6 - 34.2 mm/s, and superficial gas velocities, Ug = 0 - 16.6 mm/s. Previous studies using a single mixing ratio found that the injection of gas into a liquid-fluidized bed decreased the superficial liquid velocity required for layer inversion. Bubble size, bed height, and superficial liquid velocity at the layer inversion point vary with the binary composition. Upon gas introduction into a liquid-solid fluidization column, the superficial liquid layer-inversion velocity increases if it occurs when there is initial bed contraction. |
