An experimental investigation on a fluidized motion conveying system

The paper presents a description and the performance characteristics of a 3.7 m long fluidized motion conveying system, which transports the dry particulate materials through closed conveying channel section at different conveyor inclinations. The conveying capacity of the system has been investigated using coal ash of median particle size 108 μm as the solid material. Data on the effect of operating superficial air velocity, channel inclination, and the material supply valve opening on material mass flux, plenum chamber pressure and the material bed depth have been presented. It is found that the increase in the operating superficial air velocity increases the material mass flow rate, which finally reaches an asymptotic value at about 1.5–1.7 Umf. It is observed that the plenum chamber pressure is independent of the flow resistance offered by the moving material bed, and is only dependent on the supply of the airflow rate into the plenum. The solids mass flow rate decreases as the conveyor orientation changes from downward to upward direction. Further, the upward inclination of the conveyor requires a higher operating superficial air velocity to start the material flow, and also increases the material bed depth in the channel. The increase in the opening of material supply valve increases both the material mass flux and the bed depth in the channel for all the cases of the conveyor inclinations. The flow visualization in the horizontal and upward incline cases of the conveyor shows that the pulsatory flow mode plays a major role in the transport of the material, whereas, only sliding bed/non-pulsatory flow mode exist in the down-incline of the conveyor. The observed flow patterns have been categorized and classified in terms of flow regimes.