Spiral wound module single-envelope

Small laboratory spiral-wound modules consist of a single membrane envelope wrapped around the collection tube, as shown in Figure 3.42. The membrane area of these modules is typically 0.2 to 1.0 m2. Industrial-scale modules contain several membrane envelopes, each with an area of 1-2 m2, wrapped around the central collection pipe. The multi-envelope design developed at Gulf General Atomic by Bray [113] and others is illustrated in Figure 3.43. Multi-envelope... 

Flat-sheet membranes are made in continuous rolls 500-5000 m long. Sheets of membrane 1-2 m long are cut and folded and then packaged as spiral-wound module envelopes. A single module may contain as many as thirty membrane envelopes. Currently, the industry standard spiral-wound module is 8 inches (1 inch = 2.54 cm) in diameter and about 35-40 inches long it contains 20-40 m2 of membrane. 

Figure 8. Construction of a single envelope spiral wound module [18],...

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