Bed collapse and expansion characteristics of multi-walled carbon nanotubes in fluidized beds

Abstract

The objective of this study was to investigate bed collapse and expansion characteristics of different types of multi-walled carbon nanotubes (MWCNTs) in fluidized bed with a 0.14 m-ID × 2.4 m-height Plexiglas column. Three types of MWCNTs were used as bed materials: (i) N, NC7000™ prepared by Nanocyl®, (ii) Sf, fine entangled MWCNTs agglomerated by strong cohesive force such as van der Waals force, (iii) Sc, coarse entangled MWCNTs with a single particle. Similarity between MWCNTs and Geldart group particles was investigated based on bed collapsing process. Results showed that bed collapsing processes of N, Sf, and Sc were similar to those of Geldart groups A, C, and B particles, respectively. Based on bed collapse and expansion characteristics, dense phase voidages of N and Sf were 0.795 and 0.921, respectively, in bubbling fluidization at superficial gas velocity of 0.19 m/s.