The position of the maximum erosion points in coal powder pneumatic transport installations, function of the bend radius / pipe diameter ratio

Abstract

One major problem of all pneumatic transport installations is the high wear resulting from abrasion at transition sections, especially bends. Using Computational Fluid Dynamics software, by changing the bend radius (BR)/pipe diameter (PD) ratio, the maximum abrasion points, particles velocity and pressure drop were monitored. It was found that as the BR/PD ratio is increased, the erosion and particle velocity values are steadily decreasing. For bends having a BR/PD ratio between 1 and 3. 25 there will be only one maximum erosion point, situated at about 45 0 from the bend entrance. For a BR/PD ratio between 3.5 and 10.25 there will be two maximum erosion points one at approximately 38 0 and the other at about 80 0 from the bend entrance. For a BR/PD ratio between 10.5 and 12 there will be three maximum erosion points one at approximately 30 0 the second at about 60 0 and the third one at approximately 83 0-87 0 from the bend entrance. As the BR/PD ratio increases, the erosion values decrease at a steady rate but the velocity and pressure drop a getting dangerously close to pipe clogging. A balance has to be kept by reaching the lowest erosion rate without clogging the pipes.