Coeficientes locais de tranferencia de calor em leito fluidizado rapido

AUTOR(ES)
DATA DE PUBLICAÇÃO

1987

RESUMO

The main goal of this work was to study the heat transfer between a gas-solids mixture and the internal of a vertical pipe in which the mixture flows under condition of Fast Fluidization. The stainless steel pipe is 6m tall and has 0,072m of internal diameter. The superficial gas velocity was in the range of 5,8 m/s to 12,8 m/s and the solids flow rate varied between 0 to 80 kg/m2s. The solid particles were glass spheres with three average diameters: 109 mm, 196 mm and 269 mm. Pressure and temperature taps were installed along the pipe and provided the experimental data. The results show that the heat transfer coefficient between the mixture and the internal wall of the pipe varies directly with the bed bulk density and inversely with the particle size. The variation with the bed height was also obtained and it was found that in the Fast Fluidization condition the heat transfer coefficient generally falls off with increasing height and that this decrease is with a decrease in solids concentration. The values for the heat transfer coefficients in the Fast Fluidization condition are intermediate between the obtained in bubbling bed and pneumatic transport conditions

ASSUNTO(S)

leito fluidizado calor - transmissão

ACESSO AO ARTIGO

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