A generalized correlation for heat transfer between a gas-solid fluidized bed of small particles and an immersed staggered array of horizontal tubes

A generalized correlation for heat transfer coefficient between a horizontal staggered tube bundle and a gas-solid fluidized bed is proposed. The correlation is based on the experimental data for heat transfer coefficient between electrically heated horizontal tube bundles (12.7 and 28.6 mm diam.) and square fluidized beds (30.5 x 30.5 cm) of alumina and silica sand. The tubes in the bundle are located at the vertices of equilateral triangles with pitch varying between 1.75 and 9 times the tube diameter. The proposed correlation is examined on the basis of existing data in the literature. The predicted values of heat transfer coefficient from the proposed correlation are, in general, in good agreement with experimental data in the literature. (Auth.)