A fluid dynamic model for catalyst flow in riser of a FCC cold pilot unity is validated by gamma ray transmission measurements

An one-dimensional model was previously used to describe solid flow and operational conditions tests. By radial gamma ray profile a two-dimensional model was evaluated taken volumetric solid fraction as experimental parameters. Literature data provide a first test for solution of the two-dimensional model equations. Then, Axial and radial catalyst profiles were measured by gamma ray transmission in the riser of the Cold Flow Pilot Unit. For fluid flow, the mathematical model is established based on the equations of conservation of momentum and mass. However, in multicomponent flows, one should have a correction factor in these equations taking into account the influence of each component in the flow. This factor is the volumetric fraction of each component. The volumetric fraction of solids was obtained by measuring the pressure profile and calculating the solids specific mass relative to riser volume. With the technique of gamma transmission radiation could be measured in one single point of the riser, direct measurement, then several points to get a more precise axial profile and better definition. The data obtained were used as parameters for the differential equations of fluid dynamic model and MATLAB solved. (author)