Convective wall-to-suspension heat transfer in circulating fluidized bed risers
- Monash Univ., Victoria (Australia). Dept. of Chemical Engineering
- Bradford Univ. (United Kingdom). Dept. of Chemical Engineering
A mechanistic model, which incorporates recent findings on the fluid dynamics in the riser of the circulating fluidized bed (CFB), is developed for predicting the suspension-to-wall heat-transfer coefficient in the riser. It is assumed that heat transfer between the gas-particle suspension and the riser wall takes place by the contact of both particle packets and an emulsion phase on the wall. A characteristic length (L), that is, a sliding distance of the emulsion phase along the heat-transfer surface, is introduced in the model, enabling the effect of the length of heat-transfer surface to be evaluated. It is found that the heat-transfer coefficient decreases with increasing L, but becomes increasingly insensitive to L when L is larger than 1 m. Agreement between model prediction and measurement is encouraging over a range of operating conditions, heat-transfer surface length, and riser diameters.
- OSTI ID:
- 367861
- Journal Information:
- AIChE Journal, Journal Name: AIChE Journal Journal Issue: 8 Vol. 42; ISSN 0001-1541; ISSN AICEAC
- Country of Publication:
- United States
- Language:
- English
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