Irrigation rate

In Central Iran, irrigation with sewage increased EDTA-extractable metals (Ni, Cr, Co, Pb, Cu, Zn and Mn) in soils. At high irrigation rates (600 tons/ha), sewage irrigation increased the concentrations of some heavy... 

Overland runoff may be expressed as a conservation of mass in a flow domain, where the excess rainfall or irrigation rate, R, is equal to the difference between the rainfall and infiltration rates ... 

In the first one,the apparent reaction rate is empirically related to the operating conditions on the basis of experimental observations. The models suggested by Henry et al. (3) and by Mears (4) belong to this category. The apparent reaction rate is assumed to be proportional to the liquid holdup in the first model and to the catalyst irrigation rate in the second one. These hydrodynamic quantities are estimated using empirical correlations based on experiments. 

The following developments will be restricted to laminar liquid flow with weak gas-liquid interactions. However, this is not a limitation of the proposed methodology which could be easily applied to any other flow regime. Applications will be presented for the modelling of the irrigation rate, the dynamic liquid holdup and the apparent reaction rate in the absence of external mass transfer limitations and in the case of non volatile liquid reactants (i.e. approximatively the operating conditions of petroleum hydrotreatment). 

Figure 4. Irrigation rate against the liquid superficial velocity. Key ------------, Equation 13 and-----------------------------------,

The averaged value of apparent reaction rate is obtained readily using the same procedure as for the irrigation rate. 

Because the irrigation rate in vacuum columns often falls below 1000 lb/(h)(ft2), it may be wise to add another 6 in to the listed HETP values as a safety factor. For the ethylbenzene/styrene system... 

In step 1, the column-diameter-to-packing-size ratio for Raschig rings can be less than 30 for scrubbing applications in which the liquid-irrigation rate is high and the column is operated at above 70 percent of flooding. 

Influence of the Reactional System on the Irrigation Rate in Trickle-Bed Reactors... 

RUIZ ET AL. Reactional System Effect on Irrigation Rate... 

Liquid irrigation rates typically between 2 and 8 gpm/ft of column cross-sectional area. 

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