Acceleration Lengths in Horizontal Dilute Phase Pneumatic Conveying

摘要

Solids in a pneumatic conveying line accelerate from the solids feed point, and after pipe bends, to a constant mean velocity if given a sufficient length of straight pipe. The pipe length required for the constant velocity to be reached, the acceleration length, is investigated in this work for flow from a solids feeder, after a single horizontal 90°sweeping bend, and after two sequential bends separated by distances up to 6 m. Results show longer acceleration lengths are generally required after bends than after the feeder, and for sequential bends the acceleration length increases with solids velocity and with the spacing between the bends. A comparison is made with existing correlations for acceleration lengths after a solids feeder.