Energy loss at bends in the pneumatic conveying of fly ash--颗粒学报PARTICUOLOGY

Tripathi, N., Sharma, A., Mallick, S. S., & Wypych, P. W. (2015). Energy loss at bends in the pneumatic conveying of fly ash. Particuology, 21, 65-73. https://doi.org/10.1016/j.partic.2014.09.003

Energy loss at bends in the pneumatic conveying of fly ash

Naveen Tripathi ^a, Atul Sharma ^a *, S.S. Mallick ^a, P.W. Wypych ^b

a Department of Mechanical Engineering, Thapar University, Patiala 147004, Punjab, India
b Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong 2500, NSW, Australia

10.1016/j.partic.2014.09.003

Volume 21, August 2015, Pages 65-73

Received 24 May 2014, Revised 19 August 2014, Accepted 28 September 2014, Available online 17 January 2015, Version of Record 6 June 2015.

E-mail: atul.sharma@thapar.edu

Highlights

• Seven existing bend models for pneumatic conveying were evaluated.

• The models provided significantly varying bend loss predictions.

• Predictions of total pipeline conveying characteristics greatly depended on bend model selection.

• Some bend models underpredicted losses in dilute phase and overpredicted in dense phase.

Abstract

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 μm; particle density: 2300 kg/m³; loose-poured bulk density: 700 kg/m³) in three test rigs (pipelines with dimensions of 69 mm inner diameter (I.D.) × 168 m length; 105 mm I.D. × 168 m length; 69 mm I.D. × 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 PCC 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.

Graphical abstract

Keywords

Pneumatic conveying; Fluidised dense phase; Bend; Pressure drop; Bend model

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