Prediction of the Limiting Flux and Its Correlation with the Reynolds Number during the Microfiltration of Skim Milk Using an Improved Model.

ABSTRACT: Limiting flux (J_L) determination is a critical issue for membrane processing. This work presents a modified exponential model for J_L calculation, based on a previously published version. Our research focused on skim milk microfiltrations. The processing variables studied were the crossflow velocity (CFV), membrane hydraulic diameter (d_h), temperature, and concentration factor, totaling 62 experimental runs. Results showed that, by adding a new parameter called minimum transmembrane pressure, the modified model not only improved the fit of the experimental data compared to the former version (R² > 97.00%), but also revealed the existence of a minimum transmembrane pressure required to obtain flux (J). This result is observed as a small shift to the right on J versus transmembrane pressure curves, and this shift increases with the flow velocity. This fact was reported in other investigations, but so far has gone uninvestigated. The J_L predicted values were correlated with the Reynolds number (Re) for each d_h tested. Results showed that for a same Re; J_L increased as d_h decreased; in a wide range of Re within the turbulent regime. Finally, from dimensionless correlations; a unique expression J_L = f (Re, d_h) was obtained; predicting satisfactorily J_L (R² = 84.11%) for the whole set of experiments.

SUBMITTER: Astudillo-Castro C 

PROVIDER: S-EPMC7695011 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature