在线阅读

Volurnes 42-43 (2019)

Volurnes 36-41 (2018)

Volurnes 30-35 (2017)

Volurnes 24-29 (2016)

Volurnes 18-23 (2015)

Volurnes 12-17 (2014)

Volurne 11 (2013)

Volurne 10 (2012)

Volurne 9 (2011)

Volurne 8 (2010)

Volurne 7 (2009)

Volurne 6 (2008)

Volurne 5 (2007)

Volurne 4 (2006)

Volurne 3 (2005)

Volurne 2 (2004)

Volurne 1 (2003)

在线阅读

Partic. vol. 43 pp. 101-109 (April 2019)
doi: 10.1016/j.partic.2018.07.001

Tribo-charging of binary mixtures composed of coarse and fine particles in gas–solid pipe flow

Haifeng Wanga, Farzam Fotovatb,*, Xiaotao T. Bic, John R. Gracec

Show more

fotovat@sharif.edu

Highlights

    • The effect of adding fines on tribo-charging of coarse glass beads was investigated. • The mixture composition with the highest amount of charge was determined. • The effect of the total particle surface area on particle mixture electrification was explored. • Electrification of particle mixtures was compared with that of fine and coarse materials alone. • A model was proposed to predict charge density of mixtures as a function of their composition.

Abstract

Experiments were conducted to investigate the effect of adding fines on the tribo-charging of coarse glass beads. Four types of fines, i.e., copper, stainless steel, uncoated and silver-coated fine glass beads, mixed with 240–830 μm glass beads were conveyed by air through a stainless-steel spiral pipe acting as a tribo-charger. Regardless of the type or electrical conductivity of the fine particles tested, adding small amounts of fines (up to 10 wt%) to coarse glass beads resulted in a sharp increase in the mass and surface charge densities of the particles. In general, the profiles of the mass and surface charge densities of the fine–coarse particle mixtures as a function of the mixture composition were determined by the relative magnitude of contact potential differences and the total surface areas of all the components. The dominant particle tribo-electrification mechanism switched from coarse particle–wall contacts to fine particle–wall contacts when the fines weight percentage in the mixture exceeded 10%. A model was developed to predict the mass charge density of binary mixtures as a function of the mixture composition.

Graphical abstract

Keywords

Tribo-charging; Electrostatics; Fine particles; Binary mixture; Gas–solid flow