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3020391 
Journal Article 
Energy loss at bends in the pneumatic conveying of fly ash 
Tripathi, N; Sharma, A; Mallick, SS; Wypych, PW 
2015 
1 
Particuology
ISSN: 1674-2001 
21 
65-73 
WOS:000356980700007 
An accurate estimation of the total pressure drop of a pipeline is important to the reliable design of a pneumatic conveying system. The present paper presents results from an investigation into the modelling of the pressure drop at a bend in the pneumatic conveying of fly ash. Seven existing bend models were used (in conjunction with solids friction models for horizontal and vertical straight pipes, and initial acceleration losses) to predict the total pipeline pressure drop in conveying fly ash (median particle diameter: 30 pm; particle density: 2300 kg/m(3); loose-poured bulk density: 700 kg/m(3)) in three test rigs (pipelines with dimensions of 69 mm inner diameter (I.D.) x 168 m length; 105 mm I.D. x 168 m length; 69 mm I.D. x 554 m length). A comparison of the pneumatic conveying characteristics (PCC) predicted using the seven bend models and experimental results shows that the predicted total pipeline FCC and trends depend on the choice of bend model. While some models predict trends that agree with the experimental results, other models predicted greater bend pressure drops for the dense phase of fly ash than for the dilute phase. Models of Pan, R. (1992). Improving scale-up procedures for the design of pneumatic conveying systems. Doctoral dissertation, University of Wollongong, Australia, Pan, R., & Wypych, P.W. (1998). Dilute and dense phase pneumatic conveying of fly ash. In Proceedings of the sixth International Conference on Bulk Materials Storage and Transportation (pp. 183-189), Wollongong, NSW, Australia and Chambers, A.J., & Marcus, R.D. (1986). Pneumatic conveying calculations. In Proceedings of the second International Conference on Bulk Materials Storage and Transportation (pp. 49-52), Wollongong, Australia reliably predicted the bend losses for systems conveying fly ash over a large range of air flows. (C) 2014 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved. 
Pneumatic conveying; Fluidised dense phase; Bend; Pressure drop; Bend model