Friction between gas-solid flow and circulating fluidized bed downer wall

Xiao Bo Qi, Hui Zhang, Jesse Zhu

Research output: Journal PublicationArticlepeer-review

16 Citations (Scopus)


Friction between co-current downflow gas-solid flow and column wall was investigated by measuring apparent and actual solids concentrations in a circulating fluidized bed (CFB) downer. A new model to predict pressure drops due to friction between the gas-solid suspension in the fully developed zone and the downer wall was developed. The results show that the friction between the gas-solid suspension and the downer wall causes a significant deviation of the apparent solids concentrations from the actual ones, especially for those operating conditions with higher superficial gas velocities and solids circulation rates. When the superficial gas velocity is greater than 8 m/s, the actual solids concentrations in the fully developed region of the downer can be up to two to three times of the apparent values. Particle diameters have different influences on the frictional pressure drops under different superficial gas velocity. After the frictional pressure drop is considered, the predicted actual solids concentrations by the proposed model agree well with the experimental values.

Original languageEnglish
Pages (from-to)318-326
Number of pages9
JournalChemical Engineering Journal
Issue number3
Publication statusPublished - 1 Sept 2008
Externally publishedYes


  • Circulating fluidized beds
  • Downer
  • Friction
  • Gas-solid two-phase flow

ASJC Scopus subject areas

  • General Chemistry
  • Environmental Chemistry
  • General Chemical Engineering
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'Friction between gas-solid flow and circulating fluidized bed downer wall'. Together they form a unique fingerprint.

Cite this