Heat transfer in three-phase (G/L/S) circulating fluidized beds with low surface tension media

Characteristics of Three-Phase (Gas–Liquid–Solid) Circulating Fluidized Beds

“…From the experimental results of previous investigators, it had been noted that the value of h TP increased with increasing U G , d P or G S ; however, it did not change considerably with varying U L . The increasing trend of h TP with U G , d P or G S could be due to the increase in the turbulence in the region adjacent to the heater surface and bed proper in the riser (Cho et al, 2001a;Kang et al, 2007;Lim et al, 2011;Mo et al, 2015), as shown in Figure 10. Son et al (2008b) examined the effects of μ L on the value of h TP .…”

“…This could be because the heat transfer would be less effective with increasing σ L . It is interesting to note that the elapsed time during which the value of ∆T could be constant decreased with increasing d P , indicating that the value of h TP increased with increasing d P (Lim et al, 2011). In a TPCFB bioreactor for treating wastewater, Kang et al (2002aKang et al ( , 2002b measured the h TP value and reported that the value of h TP increased with increasing U G or holdup of biofilm media (anion polymer resin) but increased only slightly with increasing U L .…”

“…The values of h TP reported in the literature (Cho et al, 2001b;Kang et al, 2002aKang et al, , 2002bKang et al, , 2007Son et al, 2008aSon et al, , 2008bLim et al, 2011) could be predicted from the following correlations in terms of operating variables (Eq. (6)) and dimensionless groups (Eq.…”

“…The effects of the σ L on the h TP were considered by Lim et al (2011), who used a mixture of water and ethanol to change σ L . From them, the value of h TP decreased with increasing σ L due to the decrease of bubbling phenomena and bubble holdup with increasing σ L .…”

“…It seemed that the stable condition of the heat transfer system could be examined by means of the temperature difference (∆T) fluctuations between the heater surface and the riser proper. Lim et al (2011) pointed out the elapsed time during which the value of ∆T-fluctuations could become a constant value. That is, from that point onward the heat transfer process could be a quasi-steady state condition, and thus stable.…”