Dense Phase Pneumatic Conveying of Powder using Fluidization

Abstract

Dense phase pneumatic conveying in a pipeline is often applied to avoid disadvantage such as high power consumption, particle breakage and pipeline abrasion. This article described mainly the dense phase pneumatic conveying in a horizontal rectangular channel using the fluidizing air. The fluidized powder conveying system consists of a powder supply vessel and a horizontal rectangular channel at the side of vessel. The powder was fluidized by air through the porous membrane at the bottom of a vessel and a horizontal channel. The powder used belongs to Geldart A particle, where the mean diameter is 53 μm, the particle density is 2523kg/m3 and the minimum fluidizing velocity is 4.329mm/s. The mass of transported powder, the bed height of powder in a vessel and the supply air pressure were measured when the fluidizing velocities at the bottom of vessel and horizontal channel were changed. The powder could be transported smoothly when the air was supplied to the bottom of vessel and the velocity of the bottom of horizontal channel exceeded the minimum fluidizing velocity. In this case, the powder was discharged smoothly from vessel to horizontal channel, and then the powder flowed easily toward the exit of horizontal channel. Therefore, the fluidizing air at the bottom of vessel and horizontal channel was important to obtain smooth powder conveying on this system. Also, the mass flow rate of powder and the solid loading ratio were estimated from the mass of transported powder against the elapsed time. As the result, the solid loading ratio had taken a one peak when the fluidizing velocity at the bottom of horizontal channel was larger than the minimum fluidizing velocity. In addition, it is found from the analyzed solid loading ratio that the high dense powder conveying was possible in this system.