Effect of magnetic field orientation on fluidized beds of magnetic particles: Theory and experiment--颗粒学报PARTICUOLOGY

Sánchez Quintanilla, M. Á., Espin, M. J., & Valverde, J. M. (2014). Effect of magnetic field orientation on fluidized beds of magnetic particles: Theory and experiment. Particuology, 12, 54–63. https://doi.org/10.1016/j.partic.2013.03.002

Miguel Ángel Sánchez Quintanilla ^a *, Manuel Jesús Espin ^b, José Manuel Valverde ^a

a Department of Electronics and Electromagnetism, University of Seville, Sevilla, Spain
b Department of Applied Physics II, University of Seville, Sevilla, Spain

10.1016/j.partic.2013.03.002

Volume 12, February 2014, Pages 54-63

Received 14 December 2012, Revised 13 February 2013, Accepted 27 March 2013, Available online 6 June 2013.

E-mail: quintani@us.es

Highlights

• Magnetite particles fluidized in a magnetic field form chains along preferential lines of contact.

• Orientation of the chains depends on the competition between magnetic forces and fluid drag.

• The field orientation changes the contact network and the tensile strength of the bed.

Abstract

Geldart-A fluidized beds of fine particles experience a jamming transition between a fluid-like state and a solid-like state at a certain superficial gas velocity, that depends on the relative strength of interparticle attractive forces with respect to particle weight. Interparticle forces provide the bed with a certain tensile strength in the jammed state. In the work presented here we analyze the behavior of a fluidized bed of magnetic particles subjected to an externally applied magnetic field, which contributes to enhance interparticle forces. The importance of the magnetic contribution to interparticle forces is measured by the changes in the tensile strength and the superficial gas velocity at the jamming transition. The link of the field orientation with the microstructure of the bed is discussed.

Graphical abstract

Keywords

Magneto-fluidization; Jamming transition; Fluidization; Fine powders; Cohesion; Magnetization

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