Modelling solids friction for fluidized dense-phase pneumatic conveying
Fluidized dense-phase pneumatic conveying of powders has a number of benefits in various industries such as coal-fired thermal power plants, chemical, cement, pharmaceutical, petrochemical plants, etc. However, reliable designing of fluidized dense phase pneumatic conveying system is significantly difficult due to the complex and turbulent nature of the flow. In the present work, power station fly ash was conveyed through different pipeline configurations. Governing equations were developed for the fluidized dense-phase flow in the pneumatic conveying system and were solved using Runge-Kutta-Fehlberg method (RKF45). The results revealed that the particle velocity and actual gas velocity and the ratio of the two velocities increase along the direction of flow, while an opposite trend was observed for the solids volumetric concentration. A particle velocity model has been developed using solid loading ratio and dimensionless velocity terms. This particle velocity model, when employed in the existing two-layer model format for solids friction factor, has provided improved scale-up predictions (under diameter and length scale-up conditions) compared to the original two-layer model.