In a circulating fluidized bed （7.8 cm-ID × 260 cm-high）, flow regime of coal-air system at room temperature has been determined.
Bituminous coal particles used were either 0.73 mm of 1.03 mm in the mean diameter having density of 1400 Kg/m³.
The transition velocities from bubbling to turbulent beds and the transport velocities between turbulent and fast beds have been determined. The resulting transition velocities between bubbling and turbulent beds were 103 cm/s for 0.73 mm and 130 cm/s for 1.03 mm coal particles, respectively. The transport velocities between turbulent and fast beds were 180 and 209 cm/s for 0.73 and 1.03 mm particles, respectively.
In addition, chocking velocities were determined at different solid feeding rates. The resulting values were in the range of 2.55-2.65 m/s for 0.73 mm particle and of 2.77-2.84 m/s for 1.03 mm particle, respectively.
The published literature data of the transition velocity between bubbling and turbulent bed have been correlated with particle properties.