ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
HEAT TRANSFER FROM AN IMMERSED SURFACE TO ADJACENT PARTICLES IN A FLUIDIZED BED THE ROLE OF RADIATION AND PARTICLE PACKING
要約
The heat transfer from a fluidized bed to an
immersed surface is examined using simplified physical models. For residence times representative
of particles in vigorously bubbling beds it is
shown that packet models using continuum properties
are reasonable only when particle diameters
are less than 0.3 to 0.6 mm. As the conduction
between a surface and adjacent particles is proportional
to the local density of particle packing,
numerical estimates of random packing densities
suggest dense phase heat transfer coefficients up to 50% greater for spherical
particles than for irregular particles. The
contribution of radiation to the total heat
flux of high temperature beds is demonstrated
to be a function of fluid mechanical variables
as well as particle size and bed and
surface temperature.