Behaviour of a Curtain of Particles Falling Through a Horizontal Gas Stream
With a view to an application of heat recovery from hot gases, the fluid dynamics of a curtain of particles falling in a horizontal gas stream has been analysed and studied in the laboratory. The apparatus involves a duct with cross-section of 0.15 x 0.60 m, in which air with a uniform velocity profile is caused to flow at velocities in the range of 0.7 to 1.2 m/s. A stream of particles is fed into the duct from above to form a curtain across the entire width of the duct. The range of particle flowrates studied was from 18 to 62 g/s. The thicknesses of the particle curtain in the direction of gas flow are 2.5 cm and 8 cm. The trajectory of the particle curtain was determined using a high-speed camera. The experimental results were compared with the trajectories predicted by simple models based on single particle and packed bed drag.