Heat transfer behavior of an isolated bubble in an incipiently fluidized bed

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20006809

Hartman, G; Wu, W; Chen, Z; Agarwal, P K

Heat transfer between the bubble and dense phases of a bubbling fluidized bed exerts a strong influence on the system performance, especially for applications involving gas-phase combustion. Surprisingly little experimental information is available on this subject in the literature. The paper reports an experimental and modeling investigation on the heat transfer behavior of isolated bubbles injected into an incipiently fluidized bed. A new single-thermocouple technique was developed for the measurement of the heat transfer coefficient. The effects of bed particle type and size, and bubble size on the heat transfer coefficient. The effects of bed particle type and size, and bubble size on the heat transfer coefficient were examined. With respect to bubble size in the size range investigated, the heat transfer coefficient was found to increase to a maximum, and then decrease as the bubble size increased. The effect of bed particle size was comparatively small. A simple mathematical model was developed which provides good agreement with experimental data. Calculations suggest that roughly 20% of the solids which move around (and through) the bubble into the wake participate in the heat exchange with bubble gas.

• Research Organization: Univ. of Wyoming, Laramie, WY (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: FC02-91ER75680
• OSTI ID: 20006809
• Report Number(s): CONF-990534--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
42 ENGINEERING
BUBBLES
FLUIDIZED-BED COMBUSTORS
FUELS
HEAT TRANSFER
MATHEMATICAL MODELS