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The role of porosity in filtration: IV. Constant pressure filtration
Author(s) -
Tiller F. M.,
Cooper H. R.
Publication year - 1960
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690060418
Subject(s) - filtration (mathematics) , constant (computer programming) , slurry , compressibility , mechanics , porosity , thermodynamics , chemistry , mathematics , flow (mathematics) , differential equation , function (biology) , mathematical analysis , physics , statistics , organic chemistry , evolutionary biology , biology , computer science , programming language
Certain assumptions which have previously served as a basis for the conventional equations employed in constant pressure filtration are shown to be in error. It is demonstrated that the specific filtration resistance, the ratio of the mass of wet to mass of dry cake, and the rate of flow, q = dv/dθ , are not constant as has been assumed. In an example it is shown that q undergoes an eightfold variation as the liquid flows from the cake surface through to the medium. Since the product α q appears in the basic differential equation, incorrect values of q lead to errors in the calculated values of α arising from experimental data. The errors are significant when thick slurries are employed. New partial differential equations are presented for flow through compressible media in which q varies with cake thickness. Modifications of the conventional constant pressure equations are presented.