Document Type : Research Article


1 Department of Mechanical Engineering, Thapar University, Patiala, Punjab, India

2 Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beersheba, 8410501, Israel


This paper presents results of an ongoing investigation into the modelling of pressure losses through bends during pneumatic conveying of fly ash. For the reliable design of pneumatic conveying systems, an accurate prediction of bend pressure drop is of paramount importance as the same can significantly influence the total pipeline pressure loss. In the present study, seven existing bend models (Schuchart, Singh and Wolf, Rossetti, Westman, Bradley, Pan, Pan and Wypych, Das and Meloy models) were used to predict the total pipeline pressure drop for conveying fine fly ash through two test rigs: 63.5 mm I.D. x 24 m long and 54 mm I.D. x 70 m long. Comparisons between the predicted pneumatic conveying characteristics using the seven bend models and the experimental data have shown that the trends and values of the total pipeline pressure drops can significantly vary depending on the choice of bend model. While some models have provided increasing values of bend pressure drops with rise in air flows, some other models have produced reversed characteristics. It is concluded that the parameter grouping used in the existing bend models are not generally capable of predicting bend pressure drop reliably and therefore, further research is required to better understand the flow mechanisms of gas-solids flows across bends towards developing improved bend models. Copyright © 2017 VBRI Press.


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