Document Type : Engineering Advance
Department of Chemical Engineering and Barcelona Research Center in Multiscale Science and Engineering, Polytechnic University of Catalonia &ndash; BarcelonaTech, C/ Eduard Maristany 10-14 (Campus Diagonal-Bes&ograve;s), 08930, Barcelona, Spain
Department of Chemical Engineering, Polytechnic University of Catalonia – BarcelonaTech, av. Diagonal 647, 08028 Barcelona, Spain and ICREA, Passeig Lluís Companys 23, Barcelona, Spain
This communication demonstrates the relevance of membrane sealing in a test cell to its performance. Membranes need to be sealed, and therefore a more or less signifcant (depending on the test cell design) peripheral part of the membrane is supported directly by the cell body (instead of a permeate spacer). Although it may seem that there should be no fltration through the membrane when it is supported by an impermeable surface, this communication demonstrates that this is not generally true due to fltration along the membrane porous support. To confrm this, experiments were performed with a cross-ﬂow test cell (GE SEPA™ CF II), blocking the membrane hydraulically from beneath in order to simulate the eﬀect of having the membrane supported by an impermeable surface. The results show that the trans-membrane volume ﬂux obtained in all cases is only slightly aﬀected by the membrane blocking. In view of this, in the cell design, care should be taken to reduce such peripheral parts of the membrane to a minimum because it may be technically very difcult to have there the same conditions of concentration polarization as over the membrane part supported by the permeate spacer.