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The mechanism of wall to fluid heat transfer in particulately fluidized beds
Author(s) -
Wasmund B.,
Smith J. W.
Publication year - 1965
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450430505
Subject(s) - heat transfer , particle (ecology) , convective heat transfer , convection , materials science , thermodynamics , fluidized bed , heat transfer coefficient , mechanics , thermal conductivity , composite material , physics , geology , oceanography
A proposed model for predicting heat transfer from a wall to a fluidized bed by particle convection has been based on particle velocities and radial temperature profiles. Solutions for two cases have been obtained: Case I: The thermal resistance in the particles is small relative to that of the film surrounding them. Case II: The resistance to heat transfer in the particle is of the same order as that in the surrounding film. These solutions have been used to calculate particle convective heat transfer coefficients for water‐fluidized beds of 1.1 mm. and 1.53 mm. diameter glass spheres. The results are compared with reported experimental data, and indicate that particle convective transfer is 50 to 60% of the total heat transfer for Case II, and 30 to 40% for Case I. In some liquid‐fluidizing systems, the thermal conductivity of the particles should have an effect, and the reason this has not been found experimentally is suggested.