Mass zone length

The expression for the effective gas phase coefficient that would account for axial dispersion and hence give a proper mass transfer zone length is ... 

Since the results of zone refining depend on the interaction of momentum, heat and mass transfer in the system, all the basic factors affecting these three processes, both molecular and convective, have to be taken into consideration. These basic factors are concentration W, Density f, viscosity /i, heat capacity Cp, temperature den-sification coefficient, thermal conductivity k, molecular dif-fusivity D, zone diameter d, zone length L, zone travel speed u, temperature difference in zone A T and acceleration g. The concentration W may affect, JJi, Cp,, k, and D as well as the properties of the P.S.Z. (mushy region). Aside from the concentration W, all... 

Experimental studies for the removal of dissolved TBP in aqueous solutions by adsorbing on a fixed bed containing Amberlite XAD-4 resin were conducted. Break through curves were established for different flow rates and feed concentrations of TBP in aqueous solutions. Break through capacity, saturation capacity and mass transfer zone length (MTZ) were estimated and the MTZ length was correlated. The distribution data of TBP on resin were measured and the equilibrium data were fitted to Freundlich isotherm model. 

When Component 1 previously adsorbed is replaced by Component 2 at Zone III, zone length will be determined from replacement equilibrium relation and mass transfer rates involved in the replacement... 

The formation of the reaction zone in the pressure-volume plane is shown in Figure 1.8 that in the pressure-distance plane in Figure 1.9. The steady-state reaction zone profiles of pressure, temperature and mass fraction are shown in Figure 1.10. The shock-front pressure and reaction zone thickness are shown as functions of time in Figure 1.11. Formation of an approximately stable reaction zone profile requires many ( 10) reaction zone lengths. 

The critical bed depth is the theoretical depth of adsorbent that is just sufficient to prevent the effluent concentration from exceeding Cb at zero time and clearly is equal to the mass transfer zone length MTZL described above. The critical bed depth may be calculated by substituting r = 0 into equation (6.55) ... 

Fig. 8.2 Relative predetonation zone length LJd versus mass concentration of 80-pm inert particles...

Based on data obtained in [14], Fig. 8.2 illustrates the decrease in pre-detonation zone length with increasing mass concentration of inert 80-pm particles, grains of sand dispersed in the hydrogenous mixture volume. Water steam condensation resulting in water drop suspension in the mixture volume also increases the probability of deflagration-to-detonation transition. 

Mass-transfer zone Design based on stoichiometry and experience Isothermal MTZ length largely empirical Regeneration often empirical... 

FIG. 16-3 Bed profiles (top and middle) and hreakthroiigh curve (hottom). The Led profiles show the mass-transfer zone (MTZ) and eqiiilihriiim section at hreakthroiigh. The stoichiometric front divides the MTZ into two parts with contrihiitions to the length of equivalent eqiiihhriiim section (LES) and the length of equivalent unused hed (LUB). 

There are two effects from the adsorbent bed depth on mass transfer. First, it is important that the bed be deeper than the length of the transfer zone which is unsaturated. The second is that any multiplication of the minimum bed depth gives more than a proportionally increased capacity. Generally, it is advantageous to size the adsorbent bed to the maximum length allowed by pressure-drop considerations. The determination of the depth of the MTZ or unsaturated depth may be determined experimentally, and applying the following relationship ... 

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