Influence of Gas Mass Flow

The parameters for the variation of gas mass flow and thus for the influence of the Re-number onto the conversion of the component SO2 are displayed in Tabs. 16.9-16.11. 

The measurements and simulations in Figs. 16.23 and 16.24 show that a high gas throughputs leads to a lower conversion and higher outlet temperature when the liquid injection is constant. There is a overlap of formation of the mass transfer surface and of mass transfer of the absorbed component An increase in gas throughput does not yield to a change of the Sh-number and thus to an enhanced heat and mass transfer. 

The functional progression dependency of the Sh-number on gas mass flow, expressed by the Re-number, is illustrated for experiment V-9 in Fig. 16.25. The curve has a maximum which is caused by the higher expansion (relative porosity) of the fluidized bed [66], In contrast to fixed beds, the energy input in fluidized beds is higher because of higher gas throughputs, and consequently the drying is faster. 

The higher enthalpy flow of the increased gas mass flow leads to a faster drying, and thus to a decreased liquid loading as well as mass transfer surface. Thus, the conversion is lower at constant conditions. 

The steady-state humidity of the gas at the outlet of the fluidized bed follows with  

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Figure 4c. Influence of gas mass flow rate in a stirred cell reactor.

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