May 22-27, 2016
Rotating fluidized beds provide unique opportunities to exploit fluidization under higher particle forces. The centripetal force in a rotating bed is typically on the order of 10 times the force of gravity. Since the force keeping the particles in the unit is larger, the drag force can also be larger, allowing for higher gas velocities. This operating regime provides opportunities for higher mass transfer, heat transfer, gas throughput, and bubble suppression.
One application for using a rotating fluidized bed in in Chemical Looping Combustion (CLC). When solid fuels are used, oxygen carrier and ash are mixed in the process. In order to maintain high carbon capture efficiencies and recyclability of the oxygen carrier, the ash needs to be separated from the oxygen carrier. This separation can be done aerodynamically since the oxygen carrier is larger and heavier then the ash. It is theorized that rotating fluidized beds could improve the separation process efficiency and throughput as compared to conventional fluidized beds.
A 43cm diameter, 2.5cm thick rotating fluidized bed has been designed and constructed to investigate the application of the rotating fluidized beds to particle separation. A series of experiments have been performed to investigate the separation of glass beads (coal ash analog) from a typical chemical looping oxygen carrier. These experiments demonstrate the use of a rotating fluidized bed for particle separation as well as investigate the operational parameters that influence the efficiency of separation.
Justin M. Weber, Richard C. Stehle, Ronald W. Breault, and Larry Shadle, "Fundamentals of rotating fluidized beds and application to particle separation" in "Fluidization XV", Jamal Chaouki, Ecole Polytechnique de Montreal, Canada Franco Berruti, Wewstern University, Canada Xiaotao Bi, UBC, Canada Ray Cocco, PSRI Inc. USA Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/fluidization_xv/60