摘要 |
An improved non-woven support screen for mass transfer devices including a first set of parallel spaced longitudinally extending filaments having a predetermined thickness or diameter and a second set of parallel spaced filaments obliquely arranged relative to the first set of filaments and having a predetermined thickness or diameter approximately 1/2 that of the first set of filaments to provide improved control of membrane distention for minimizing the masking of the membrane surface by preventing excessive distention in one plane, to reduce the volume of body fluid layer in the membrane (low prime), and provide improved mass transfer efficiency while maintaining gentle mixing of the body fluid. Moreover, the velocity gradient of the exchange fluid is enhanced by the limited space provided for the exchange fluid channels to significantly improve the scrubbing action of the exchange fluid on the membrane surface. Advantageously, the larger diameter of the filaments of the first set provides low operating fluid pressure within the membrane channels by allowing selective distention of the membrane.
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