The gas-solid suspension drag on large particles in the transport zone of a circulating fluidized bed

Conference contribution, 2021

The effective drag of the gas-solid suspension on large particles representing fuel particles in fluidized beds, has a crucial effect on the mixing of the fuel particles. The suspension drag is therefore an important parameter in CFB reactor modeling, but little is known on its magnitude. This paper presents a method to experimentally determine the suspension drag by measuring the terminal velocity of large particles in the transport zone of a fluidized bed, which is compared with the terminal velocity in the absence of bed material. The drag coefficient of the particles suspended in the gas-solids flow and Reynolds numbers of the fluid flow are presented and compared to the standard drag curve of a single spherical particle. Finally, the effective viscosity of the gas-solid suspension is determined.