Narrative: Knowledge on solids circulation, mixing and their relation to heat transfer in a fluidized bed is of critical importance to the design of fluidized bed combustors and chemical reactors and to the development of a rational procedure for scale- up. To date systematic, quantitative data on the subject have been limited. Accordingly, it is proposed to design and build a radioactive particle tracking facility in order to study the hydrodynamics, mixing, segregation and heat transfer in atmospheric and pressurized fluidized beds. This versatile facility makes use of radioactive tracer particles which are dynamically identical to the particles to be studied. The motion of the tracer particles is tracked by an array of scintillation detectors and analyzed by an on-line computer. The solids velocity and occurrence probability of any particular species of particles can be obtained by using a tracer which matches their density, size, and shape. The results are expected to contribute to the formulation of the scaling laws for fluidized bed design. The proposed investigation will include: (1) Construction of a 12-inch diameter bed, (2) Measurements of mean and fluctuating components of solids motion, (3) Measurements of particle size and density segregation, (4) Measurements of solids mixing, (5) Influence of bed hydrodynamics on heat transfer to or from immersed surfaces and (6) Measurements of the hydrodynamics of solids in pressurized fluidized beds.
