Computational study of the bubbling-to-slugging transition in a laboratory-scale fluidized bed(PPT)

摘要

1. The bubbling-to-slugging transition is a gradual process, not an abrupt event: 1.1. The bubbling-to-slugging transition occurs over a range of flows, 1.2. Bubble coalescence begins near top of the bed and progresses downward as gas flow increases, 1.3. Slugging becomes fully development when the first major bubble coalescence occurs neat the distributor. 2. It may be easiest to detect the initial transition toward slugging fluctuations (bubble behavior); 3. Statistical and temporal analyses of local pressure and void fluctuations can be used to develop quantitative metrics to indicate/diagnose the slugging transition; 4. MFIX and MS3DATA are useful tools for understanding the complex relationship between dynamic pressure and void fluctuations (bubble behavior); 5. The optimal degree of slugging for fast pyrolysis of biomass has not yet been resolved.