Membrane modules short flow-path

Short flow path disc-tube (DT) RO membrane modules developed by Rochem for treating highly turbid waters and folding feeds are now used extensively to minimise concentration polarisation, seating and fording. Typically, for RO systems the Silt Density Index (SDI) of feed water must be less than 5 to prevent premature fouling. 

Figure 1.24 A ROCHEM short flow-path membrane module. Each disc is 8cm long.

A novel membrane module design. Top Cross-sectional view of a membrane-coated channel. Bottom Channel flow pattern. High surface-area modules could reduce the relative cost of pervaporation. The short, narrow, non-uniform, multi-path channels that create higher shear ate formed. The turbulence promoting pathways could go a long way to mitigate fouling in ultrafiltration and microfiltration membrane systems. 

A schematic flow path in a plate-and-frame module is illustrated in Figure 5.4. In order to reduce channeling (tendency to by-pass parts of the membrane along a short cut) and to establish a uniform flow distribution baffles have been introduced. ... 

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