Flat-plate membrane

C. W., Progress in the Testing and Development of Practical Flat Plate Membrane Oxygenators for Cardiopulmonary Assist, Artif. Heart Prog. Con/. Proc., p. 417-430 (June 9-13, 1969). 

The two most common membrane geometries are the flat plate and the tube. Single flat plate membranes are usually used in laboratory scale investigations due to their ease of fabrication. Tubular membranes are more and more popular due to their much larger ratio of the membrane surface area to the equipment volume than flat plate membranes [4]. OITM reactor configurations with multi-planar or multi-tubular structures are required for commercial use. 

The second category of membrane designs which has enjoyed wide scrutiny is flat plate membranes. Under the heading of flat plate membranes, two varieties have been investigated. Self-supporting, flat membranes have been used by a wide number of researchers in small scale experiments. However, this type of membrane has Umited potential for scaUng up and for application under high pressure... 

An example of the internal structure of the microchanneled, flat plate membranes developed by Air Products and its partners Ceramatec and SOFCo EFS, is... 

Develop the material balance equations that describe the steady-state axial concentration profiles in a flat plate membrane dialyzer used as an artificial kidney. A schematic is shown below ... 

Based on the examinations of sensitivity, precision, accuracy and valid range, they concluded that this is a promising technique to measure cake thickness of biological particles. This method has the benefits of low cost, easy installation and accuracy compared to gamma-ray absorption, NMR microimaging and computerized axial tomographic scans (CATSCAN) techniques. The fact that this method can only be applied to a flat plate membrane module is its major limitation. 

Parallel-Leaf Cartridge. A parallel-leaf cartridge consists of several flat plates, each having membrane sealed to both sides (Fig. 13). The plates have raised (2—3 mm) rails along the sides in such a way that, when they are stacked, the feed can flow between them. They are clamped between two stainless-steel plates with a central tie rod. Permeate from each leaf drains into an annular channel surrounding the tie rod (33). 

Another type has several flat plates manifolded into a plastic header. The surface of the laminate is suitable for dip-casting membranes, whereas the interior is several orders of magnitude more porous. Permeate collects in the center of the laminate and drains into the header. 

Assessment of membrane damage was based on performance testing before and after chemical exposure. Testing was conducted in a small flat plate reverse osmosis unit designed to accommodate membrane discs of 45 mm diameter. Feed solution reservoir temperature was maintained at 25 1°C and the brine was continuously recirculated through a filter at the rate of 600 mL/min. Concentration polarization is considered negligible in this cell under these conditions. 

The cells can be entrapped by inclusion within membrane filter devices, such as hollow-fiber, flat plate, and spiral wound units. 

The membrane module and design will obviously depend on the type of membrane used. The flat-sheet membranes are commonly constructed in a plate-and-frame configuration or as spiral-wound (SW) modules. F1F/CT/MTmembrane types are commonly manufactured into bundles that are installed in housing units or designed to be unconfined in the fluid, that is, immersed units. The membranes are... 

High flow rates across the membrane surface help reduce the accumulation of solutes rejected by the membrane (referred to as concentration polarization) and impurities lodged on the membrane surface (i.e. fouling ). (See Section lbii.) Tubular membranes and flat-sheet membranes installed in thin channel plate-and-frame... 

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