Fundamental Principles Laminar Boundary Layer Flow Laminar Duct Flow External Natural Convection Internal Natural Convection Transition to Turbulence Turbulent Boundary Layer Flow Turbulent Duct Flow Free Turbulent Flows Convection with Change of Phase Mass Transfer Convection in Porous Media.

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Convection Heat Transfer

http://digital.csic.es/bitstream/10261/78793/1/Progress%20in%20chemical-looping%20combustion%20and%20ref....2012.pdf

Progress in chemical-looping combustion and reforming technologies

Recycling and recovery routes of plastic solid waste (PSW): A review

For fluid-solid reactions, a random pore model is developed which allows for arbitrary pore size distributions in the reacting solid. The model can represent the behavior of a system that shows a maximum in reaction rate as well as one that does not, and it identifies an optimal pore structure for either of such systems. It is demonstrated that the new model subsumes several earlier treatments as special cases. By comparison with the grain model, a relationship is derived between the effective grain shape factor and a pore structure parameter defined here. When the variance of the pore size distribution is effectively zero, the new results approach those predicted by the Petersen (1957) model over a large range of conversions. The char gasification data of Hashimoto et al. (1979) are shown to produce correlations consistent with the expectations of the new model.

A random pore model for fluid‐solid reactions: I. Isothermal, kinetic control

Fuel nitrogen conversion in solid fuel fired systems

Applying both their own assumptions and the mechanism of lateral mixing proposed by Ranz (20), the authors obtained theoretical formulas for effective thermal conductivities ke in packed beds. Previously reported experimental data were analyzed with these equations, and the usable data for predicition of ke were shown.

In order to see the influence of both packing characteristics and temperature on the effective thermal conductivities, experimental data were obtained with air for beds with various kinds of packing, i.e., iron spheres, porcelain packings, cement clinker, insulating fire brick, and Raschig rings. Correlation of these data with Equation (15) showed that this equation adequately expressed the heat transfer mechanisms in packed beds with motionless gases, especially at hight temperatures.

Studies on effective thermal conductivities in packed beds

From studies of annular packed beds wherein the heat flows purely radially, the authors obtained the coefficients of heat transfer on the inner tube surface, as well as the mean effective thermal conductivities of bed. The inner and outer diameters of the annular packed bed were 22 and 70 mm. respectively, and the packings shown in Table 1 were used. The wall film coefficients obtained with air flowing axially through the bed were correlated for NReM < 600 by means of Equation (14).

The coefficients of heat transfer for cylindrical packed beds reported previously by other observers were correlated also by Equation (14), with 0.054 used for values of αω in the range NReM < 2,000.

Consideration of Equation (14) in terms of a theoretical model of heat transfer showed that it was reasonable to apply it for the prediction of wall film coefficient, especially for low Reynolds numbers.

Studies on heat transfer near wall surface in packed beds

Circulating fluidized-bed reactors

Studies on combustion of carbon particles in flames and fluidized beds

Part 1 presents reactor models for all regimes of behavior of dense bubbling fluidizing beds, and the single parameter appearing throughout is the mean bubble size in the bed. The models are simple in that they do not require numerical solution, and they reasonably fit the reported data for these systems. Part 2 develops a freeboard entrainment reactor model to account for the extra conversion taking place above the dense bubbling bed. This model extends naturally to fast fluidization and other lean-phase contactors such as the circulating fluidized bed and suggests what type of information is needed to make reliable reactor performance predictions in these systems

Daizo Kunii

Papers

Studies on effective thermal conductivities in packed beds

Studies on heat transfer near wall surface in packed beds

Circulating fluidized-bed reactors

Studies on combustion of carbon particles in flames and fluidized beds

Fluidized reactor models. 1. For bubbling beds of fine, intermediate, and large particles. 2. For the lean phase: freeboard and fast fluidization