Modeling pressure drop in curvature and reacceleration zones in bends during pneumatic conveying of fine powders

This paper presents the results of ongoing research aimed at modeling the pressure drop in bends during pneumatic conveying of fine powders. Based on the test results of conveying fly ash and two grades of cement through three different radii of curvature of the bends, two different bend diameters, and two different locations of the test bend, a semi-empirical relationship was developed for bend loss with various pressure drop components modeled separately. The newly developed model was used to predict the bend loss for a solid loading ratio in the range of 51–170 (very dense phase). The proposed model exhibited a satisfactory level of prediction accuracy, with relative error percentages of less than 12.2% and 19.6% for the high and low solids loading ratios, respectively.