Numerical and experimental study of an innovative design of elbow in the pipe line of a pneumatic conveying system

Direction of material flow changes during conveying materials through elbows. In pneumatic conveying systems, direction changes (elbows) cause energy loss and product damage. Various types of elbows are used in the pneumatic conveying systems to solve these problems. This paper introduces a novel solution, named "elbow with auxiliary air". Conventional and three novel elbows (introducing auxiliary air at 45, 60 and 90 to initial flow) were compared numerically and experimentally while conveying corn and barley at 15, 25, 35 and 45 m s(-1). Euler-Lagrangian computational fluid dynamics models were used to solve for pressure distribution and particle trajectories. Numerical model results agreed with empirical experiments results. While conveying corn and barley the average pressure drop for novel elbow with auxiliary air at 45 was 21% less than for the standard elbow. In conventional elbows seeds contacted duct walls multiple times, but rarely contacted them in the 45 elbow with auxiliary air. The novel elbow can reduce pneumatic conveying energy requirements and lessen seed damage and dust generation. (C) 2018 Published by Elsevier B.V.