Design parameter effects on expansion in fluidized beds with inserts

The effect of some design parameters on the expansion of particles has been studied in a fluidized bed of 300 mm diameter. Four distributors were examined; three perforated plates, each perforated by holes of 0.8 mm in diameter but different hole densities at 6 mm, 9 mm and 12 mm pitch, and a porous plastic distributor 17 mm thick. Particles of different materials in the Archimedes number range from 100 to 10⁵ were fluidized. The inserts were held vertically as arrays. All experimental data for four distributors were correlated within experimental error by the equation: (U - U_mf/U_o-U_mf) = (e-e_mf/1-e_mf)^{(1.28+0.00033P3)} where U, U_mf U₀ are the gas velocity, velocity at minimum fluidization and real or apparent terminal velocity, while e is the bed porosity and e_mf is the porosity at the condition of minimum fluidization. P is the hole pitch of perforated plate distributor in millimeters.