used four tangential air entry nozzles in a second stage. They reported that such an arrangement improved the mixing between gas and solids leading to better combustion.Kaewklum et al. [8] studied hydrodynamic regimes and characteristics of two types of conical swirling fluidized beds: one having tangential gas entry through four nozzles and second having an axial entry through an annular-spiral gas distributor. They reported four regimes in bed operation and empirical equations for predicting minimum fluidization velocity and bed pressure drop at minimum fluidization. A conical swirling fluidized bed combustor having an annular-spiral air distributor was used by Kaewklum and Kuprianov [7] to investigate hydrodynamics, combustion and emission characteristics. They reported four regimes of bed operation and very high combustion efficiency.