Cohesivity, Formation of Particle Clusters, and Blanket Settling Velocity in a Fluidized Bed

Illangasinghe, W, Ratnayaka, N, Manatunge, J and Jayasuriya, L 2019, 'Cohesivity, Formation of Particle Clusters, and Blanket Settling Velocity in a Fluidized Bed', Journal of Environmental Engineering (United States), vol. 145, no. 4, pp. 1-7.


Document type: Journal Article
Collection: Journal Articles

Title Cohesivity, Formation of Particle Clusters, and Blanket Settling Velocity in a Fluidized Bed
Author(s) Illangasinghe, W
Ratnayaka, N
Manatunge, J
Jayasuriya, L
Year 2019
Journal name Journal of Environmental Engineering (United States)
Volume number 145
Issue number 4
Start page 1
End page 7
Total pages 7
Publisher American Society of Civil Engineers
Abstract This study describes the formation, particle clustering, settling mechanism, and settling velocity (Vs) in a fluidized bed reactor using laboratory and field experiments based on its cohesivity, which is expressed as a sludge cohesion coefficient (SCC). At a constant upflow, solid loading leads to particle interactions that result in an increase in the floc size. The blanket thickens and reaches a steady state, at which point the blanket height remains static and Vs reaches two to four times higher upflow velocity. During the steady state, SCC increases with time (0.6-0.8 mm/s) and Vs decreases, whereas no significant variation in sludge volume (SV) is observed. Comparing the nondimensional parameter Vs/SCC with the voidage (1-SV), the Reynolds number (R) of the blanket is 3. At a high R, hydrodynamic forces tend to overcome the adhesive forces. Turbulent conditions created by larger and faster settling clusters lead to their destruction, resulting in the formation of smaller subclusters. This increases the interstitial area between the clusters and reduces Vs. Blanket cohesivity increases due to the short-ranged cohesive forces between particles.
Subject Water Treatment Processes
Civil Engineering not elsewhere classified
Chemical Engineering not elsewhere classified
Keyword(s) Cluster formation
Cohesivity
Floc blanket
Particle settling
Sludge cohesion coefficient
DOI - identifier 10.1061/(ASCE)EE.1943-7870.0001512
Copyright notice © 2019 American Society of Civil Engineers
ISSN 0733-9372
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 0 times in Thomson Reuters Web of Science Article
Scopus Citation Count Cited 0 times in Scopus Article
Altmetric details:
Access Statistics: 17 Abstract Views  -  Detailed Statistics
Created: Tue, 26 Mar 2019, 09:36:00 EST by Catalyst Administrator
© 2014 RMIT Research Repository • Powered by Fez SoftwareContact us