Revisiting classification of powders based on interparticle forces

An extended classification of powders based on their fluidization behavior is proposed for describing their fluidization behavior. This classification takes into account the interparticle forces acting on parti-cles. A diagram is generated, using existing data in the literature, in which the dimensionless interparticle force is plotted against the Archimedes number. At a specific Archimedes number (fixed solid and liquid), type D behavior is expected when dimensionless interparticle force is extremely low. Increasing the interparticle force can change the type of powder to B, then A and finally type C behavior would be encountered at high enough value of dimensionless interparticle force. Clear boundaries were detected between different fluidization behaviors in the proposed diagram. Geldart boundaries, which can be used in the absence of interparticle forces, coincide with the newly proposed boundaries. The absence of an apparent interparticle force can be interpreted as the presence of van der Waals force among particles while no other type of interparticle force is induced on particles. The advantage of considering the boundaries presented in this work is that they can identify the type of fluidization when interparticle forces are significant, which cannot be detected with the extended classifications already available in the literature. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

An extended classification of powders based on their fluidization behavior is proposed in this study, taking into account the interparticle forces acting on particles and generating a diagram to depict the relationship between dimensionless interparticle force and Archimedes number. Clear boundaries between different fluidization behaviors were detected in the proposed diagram, and the advantage of considering these boundaries is to identify the type of fluidization when interparticle forces are significant.