Measuring fuel mixing under industrial fluidized-bed conditions - A camera-probe based fuel tracking system

It is shown that the new fuel tracking method can withstand industrial conditions. Applying the method gives reproducible results and yields lateral dispersion coefficients in the range 10−3-10−2 m2/s for both pellets and wood chips. The lateral mixing of the fuel increases with fluidization velocity and, to a minor extent, with the cross-flow of bulk solids. As observed in previous work, the location of fuel particles on the bed surface confirms the existence of preferred bubble paths, and these are smeared out by the cross-flow of bulk solids. The vertical mixing is hindered by the cross-flow of bulk solids, while it is enhanced by fluidization velocity, which is in agreement with previous research.