Operating pressure drop and minimum fluidizing velocity were studied in a flat spout-fluid bed using sub-millimetre grade silicon particles. The influence of introducing a nonporous draft tube of different configurations as well as fluidizing gas on the two parameters was investigated. A comparison of fluidizing gas systems indicated that introduced gas restrained gas bypassing to lower the minimum fluidizing velocity; however, the operating pressure drop was higher than systems without the existence of fluidizing gas. Two new correlations that took into account the effects of bed geometry and fluidizing gas on the operating pressure drop and minimum fluidizing velocity were developed based on the experimental data, which were in agreement with the present experiments.