Spiral wound configuration

Basically, the spiral-wound configuration consists of a jelly roll-like arrangement of feed transport material, permeate transport material and membrane material. At the heart of the wall is a perforated permeate collector tube. Several rolls are usually placed end to end in a long pressure vessel. 

Manufacturer Location Brand Membrane Material Spiral Wound Configuration... 

VOCs can also be removed by applying vacuum and using composite membranes as, for example, in the VaporSep process commercialized by the MTR, where a porous support is used for a silicone membrane coating in a spiral wound configuration. Hydrophobic polypropylene hollow fibers with an ultrathin and highly VQC-permeable plasma-polymerized nonporous silicone skin on the outer surface can be also effective [31-33]. 

Most of the commercially available NF membranes are made in spiral wound configuration. 

A new type of configuration, the flowing liquid membrane (FLM) was studied by Teramoto et al. [20]. In this case, the membrane liquid phase is in motion as the feed and strip phase. In this type of system a plate-and-frame and spiral-wound configuration with flat membrane was used. The scheme of the FLM configuration is drawn in Fig. 7.3A. The hquid phase flows (FLM) between two hydrophobic microporous membranes. The two membranes separate the hquid membrane phase from feed and strip phases. In Fig. 7.3B, it is reported the classical plate-and-frame module employed for the separation of ethylene from ethane [20]. The liquid membrane convection increased the membrane transport coefficient in gas separation. However, the membrane surface packing density (membrane surface area/ equipment volume) is much lower in spiral-wound system than in hollow fiber. 

The spiral-wound configuration tFigure 17-lQ is more conplicated but has a significandy higher surface area per unit volume. With proper design of the channels there will be significant turbulence at the membrane surface that promotes mass transfer. These systems have been used for carbon dioxide recovery, UF of relatively clean solutions and RO. 

Fouling is typically associated with microfiltration and ultrafiltration due to the employment of porous membranes combined with the characteristics of the feed solution. In the case of e.g. reverse osmosis where low molecular solutes such as salts are retained the fouling tendency is low. But foulants such as organic and inorganic precipitates and suspended solids may be present as well. Since in these systems often hollow fiber and spiral wound configurations are applied fouling may occur in the feed channels since these configurations are very susceptible and measures have to be taken and this will be described in the next section. 

Reverse Osmosis 26 J97ATZ,4gl Spiral wound configuration 468... 

GRACE Systems Cellulose acetate membranes are also used in spiral-wound configuration. Their data, reproduced in Figures 10.16,10.17, and 10.18, indicate that the permeability, defined as mol/m s kPa, increases with an increase in transmembrane pressure, for both methane and CO2. However, the... 

In the spiral-wound configuration membranes are sandwiched together with feed flow channel spacers and the porous membrane support around a central permeate collecting tube (Fig. 2.3b). Commercial systems are about 1 meter long with diameters between 10 and 60 cm. Membrane areas can be in the range of 3-60 m. Spiral-wound membranes offer a good membrane surface/volume and low capitaEoperating cost ratios. Nevertheless, they cannot be mechanically cleaned and a feed pretreatment is required. 

In the spiral-wound configuration an envelope is formed with two membrane sheets separated by a porous support material. Typically the module consists of several such envelopes. The material between the membranes (permeate channel spacer) supports them against the operating pressure and defines the permeate flow channel. The envelope is sealed on three sides. The fourth side is sealed to a perforated permeate collection tube, and the envelope is wrapped around the collection tube with a net-like spacer sheet that has two functions ... 

Spiral Wound The spiral-wound membrane geometry in MF and UF is not widely used in surface water treatment because spiral-wound membranes cannot be backwashed, and extensive pretreatment is therefore required to keep the membrane from clogging. However, there are some applications in groundwater treatment where surface water UF membranes are applied to remove color (Nystrom et al., 1999). In the spiral-wound configuration, two flat sheets of membrane are separated with a permeate collector channel material to form a leaf. This assembly is sealed on three sides, with the fourth side left open for permeate to exit. A feed/brine spacer material sheet is also included in the leaf assembly. A number of these assemblies or leaves are wound around a central plastic permeate tube. This tube is perforated to collect the permeate from the multiple leaf assemblies (Hydranautics, 2001). Most commercial lengths are 1 or 1.5 m and 20 cm in diameter (Fig. 6.7). 

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