Mass flow rate through packed

Related Calculations. Apart from the rule of thumb concerning superficial velocity (see step 1), be aware of similar guidelines that pertain to mass flow rate through the absorption tower. For plastic packing, the liquid and gas flow rates are both typically around 1500 to 2000 lb/h per square foot of tower cross-sectional area for ceramic packing, the corresponding range is about 500 to 1000 lb/h. 

This suggests that external mass transfer resistance is not very important for (1) low rates of reactant conversion, (2) small catalytic pellets with large external surface-to-volume ratios, and (3) high gas-phase flow rates through the packed... 

The problem of interparticular volume does not exist in systems in which a membrane is used as the separation medium. Both theoretical calculations and experimental results [79] clearly document that membrane systems can be operated in a dead-end", or filtration mode at much higher flow rates than packed beds because all the substrate solution flows through the support and the mass transfer is much faster as a result of this convective flow. Obviously, a reasonable compromise between the membranes with their fast mass transfer and beads with high capacity may result in separation media with enhanced properties. 

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