Density segregation of dry and wet granular mixtures in gas fluidized beds. Issue 12 (1st August 2015)

• Record Type: Journal Article
• Authors: Seah, Stella Lin Li; Lim, Eldin Wee Chuan
• Is Part Of: AIChE journal. Volume 61:Issue 12(2015:Dec.)
• Page Start: 4069
• Page End: 4086
• Publication Date: 2015-08-01
• Subjects: mixing and segregation -- wet granular materials -- fluidized beds -- discrete element method -- computational fluid dynamics; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; 660.28
• DOI: 10.1002/aic.14959
• Languages: English
• ISSNs: 0001-1541

Abstract

Abstract : The Discrete Element Method combined with Computational Fluid Dynamics was coupled to a capillary liquid bridge force model for computational studies of mixing and segregation behaviors in gas fluidized beds containing dry or wet mixtures of granular materials with different densities. The tendency for density segregation decreased with increasing fluidizing velocity, coefficient of restitution, and amount of liquid present. Due to the presence of strong capillary forces between wet particles, there was a high tendency for particles to form agglomerates during the fluidization process, resulting in lower segregation efficiency in comparison with fluidization of dry particles. Particle‐particle collision forces were on average stronger than both fluid drag forces and capillary forces. The magnitudes of drag forces and particle‐particle collision forces increased with increasing fluidizing velocity and this led to higher mixing or segregation efficiencies observed in dry particles as well as in wet particles at higher fluidizing velocities. © 2015 American Institute of Chemical Engineers AIChE J, 61: 4069–4086, 2015