Flow in Fixed Beds

M. D. Mantle, A. J. Sederman, L. F. Gladden 2001, (Single- and two-phase flow in fixed-bed reactors MRI flow visualisation and lattice-Boltzmann simulations), Chem. Eng. Sci. 56, 523. 

A.l. High Spatial Resolution of Fluid Flow in Fixed-Bed Reactors... 

Figure 5.2-2. Patterns in gas-liquid downwards flow in fixed beds (after Charpentier [13]).

X. Cocurrent gas-liquid flow in fixed beds Downflow in trickle bed and upflow in bubble columns. Literature review and meta-analysis. Analyzed both downflow and upflow. Recommendations for best mass- and heat-transfer correlations (see reference). [95]... 

Application of a Eulerian-Eulerian approach to modeling flow in fixed bed as well as trickle bed reactors is discussed. A methodology of applying computational flow... 

Mantle, M.D. Sederman, A.J. Gladden, L.F. 60. Single and two-phase flow in fixed-bed reactors ... 

Spedding, P.L. Spencer, R.M. Simulation of packing density and liquid flow in fixed beds. Comput. Chem. Eng 195, 19, 43. 

Voidage. Single- and two-phase flows in fixed-bed reactors were visualized by three-dimensional NMR imaging and MRI velocimetry. The fluid velocity vector is determined at a pore-scale resolution of 156 pm. Characteristics of... 

The examples just presented show that axial dispersion has only a small effect on reactor performance for single-phase flow through a packed bed of particles. With two-phase flow through a packed bed or with gas flow in a fluidized bed, dispersion effects can be quite important because of the complex flow patterns these cases are discussed in later chapters. Complex flow patterns can also occur for various reasons with single-phase flow in fixed beds, and then reactor performance may be worse than predicted allowing for normal axial dispersion. When abnormal flow patterns are suspected because of poor reactor performance, the residence time distribution should be investigated. 

Highly turbulent flow in fixed beds is only possible, however, if the bed is constrained so that the individual grains within it cannot move. If the bed is not constrained and the flow through it is upwards, the bed becomes fluidized. 

Dwivedi and Upadhyay have analyzed the experimental data on mass transfer between fluid and particles in fixed and fluidized beds, previously obtained by many authors. From their collection of data referring to gas flow in fixed beds we have found the following correlation, valid for 10 ... 

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