Rectangular cross-flow module

Li and Sirkar (2004, 2005) reported on novel hollow-fiber membranes and modules for use in both DCMD and VMD configurations. The presented new types of membranes were commercial porous PP hollow fibers (Accurel MEMBRANA, Wuppertal, Germany) of different dimensions and thicknesses coated with a variety of ultrathin microporous silicone-fluoropolymer layer on their external surface by plasma polymerization at Applied Membrane Technology (AMT) Inc. (Minnetonka, MN). The fibers were arranged in a rectangular cross-flow module design for the hot feed to flow over the outside surface of the fibers and to reduce the temperature polarization effect. Both the DCMD and VMD... 

Figure 12.6 Rectangular cross-flow module used in Li and Sirkar (2004, 2005).

The concept of cross-flow microfiltration is shown in Figure 16.11, which represents a cross-section through a rectangular or tubular membrane module. The particle-containing fluid to be filtered is pumped at a velocity in the range 1-8 m/s parallel to the face of the membrane and with a pressure difference of 0.1-0.5 MN/m2 (MPa) across the membrane. The liquid penneates through the membrane and the feed emerges in a more concentrated form at the exit of the module.1617 All of the membrane processes are listed in Table 16.2. Membrane processes are operated with such a cross-flow of the process feed. 

Duct flows can be converted into efficient mixing flows (i.e., flows with an exponential stretch of material lines with time) by time- modulation or by spatial changes along the duct axis. One example of the spatially periodic class is the partitioned-pipe mixer (PPM). This flow consists of a pipe partitioned with a sequence of orthogonally placed rectangular plates (Fig. 5a). The cross-sectional motion is induced through rotation of the pipe with respect to the assembly of plates, whereas the axial flow is caused by... 

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