Influence of solids hydrodynamics on local heat transfer from tube banks immersed in a gas fluidized bed

Conference · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5843513

Moslemian, D; Chen, M M; Chao, B T

Many empirical correlations for predicting heat transfer between a gas fluidized bed and the immersed internals have been proposed. They are based mainly on gross experimental observations with minimal attention to the mechanism of heat transfer due, at least in part, to the lack of systematic data on solids motion. Much useful insight can be obtained from a simultaneous determination of the local heat transfer rates from immersed internal structures and the associated hydrodynamics of the solid particles. In this study, the local mean heat transfer coefficients of horizontal internals simulating tube banks were measured for several locations in the bed along with measurements of the mean solids velocity and density distributions for a range of superficial gas velocities. The experiments were conducted in a 184 mm (7.25 in.) ID air fluidized bed with a horizontal in-line internal rod bundle of 16 mm (0.625 in.) OD with pitch-to-diameter ratio of 4 over a wide range of gas velocities. The results showed that the local heat transfer rates depend strongly on the flow pattern of solids induced by the bubble motion. The data confirmed the expectation that particle convection plays a major role in the mechanisms of heat transfer from immersed internals.

• OSTI ID: 5843513
• Report Number(s): CONF-861211-
• Resource Relation: Conference: American Society of Mechanical Engineers winter meeting, Anaheim, CA, USA, 7 Dec 1986; Other Information: Technical Paper 86-WA/HT-77
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FLUIDIZED BED BOILERS
HYDRODYNAMICS
THERMODYNAMICS
FLUIDIZED-BED COMBUSTORS
AIR FLOW
CONVECTION
CORRELATIONS
FLUIDIZED BEDS
FLUIDIZED-BED COMBUSTION
HEAT EXCHANGERS
HEAT TRANSFER
PERFORMANCE
RODS
SOLIDS FLOW
BOILERS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTORS
ENERGY TRANSFER
FLUID FLOW
FLUID MECHANICS
GAS FLOW
MASS TRANSFER
MECHANICS
OXIDATION
THERMOCHEMICAL PROCESSES
421000* - Engineering- Combustion Systems