Rotating distributor fluidized bed
This lab-scale fluidized bed is equipped with an electrical motor in order to produce the horizontal rotation of the distributor. The cylindrical vessel has an inner diameter of 0.192 m and a height of 1 m. The rotating distributor is a perforated plate with an open area ratio of 3% and the holes are laid out in a triangular mesh with a pitch of 11 mm. The rotating velocity varies from 0 (static distributor) to 100 rpm. The main advantage of this facility is the structuring effect induced in the fluidization behavior by the distributor rotation. The dynamic structure imposed by the rotating distributor causes the following advantages:
The minimum fluidization velocity decreases as the rotational speed of the distributor increases, facilitating the fluidization.
The rotation introduces a radial component to the predominant axial component of the flow present in conventional fluidized beds.
The influence of the distributor motion on the bed dynamics reaches up to 11 cm above the distributor, permitting its use in very shallow beds.
The rotation of the distributor breaks the layout of gas jets and stagnant zones between the holes of the distributor, improving the radial and axial mixing at the bottom of the bed.
The rotating distributor prevents the appearance of channels during agglomeration processes, and thus, reduces the risk of the bed defluidization.
In drying processes, the drying time is reduced when it is compared to the static distributor case.