초록 ▼

A vertical skein of “fibers”, opposed terminal portions of which are held in headers unconfined in a modular shell, is aerated with a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brash for the outer surfaces of the fibers. The membrane device is surprisingl

A vertical skein of “fibers”, opposed terminal portions of which are held in headers unconfined in a modular shell, is aerated with a gas-distribution means which produces a mass of bubbles serving the function of a scrub-brash for the outer surfaces of the fibers. The membrane device is surprisingly effective with relatively little cleansing gas, the specific flux through the membranes reaching an essentially constant relatively high value because the vertical deployment of fibers allows bubbles to rise upwards along the outer surfaces of the fibers. Further, bubbles flowing along the outer surfaces of the fibers make the fibers surprisingly resistant to being fouled by build-up of deposits of inanimate particles or microorganisms in the substrate provided that the length of each fiber is only slightly greater than the direct center-to-center distance between opposed faces of the headers, preferably in the range from at least 0.1% to about 5% greater. For use in a large reservoir, a bank of skeins is used with a gas distributor means and each skein has fibers preferably >0.5 meter long, which together provide a surface area >10 m2. The terminal end portions of fibers in each header are kept free from fiber-to-fiber contact with a novel method of potting fibers.

대표청구항 ▼

In a process for maintaining the outer surfaces of hollow fiber membranes essentially free from a build-up of deposits of particulate material while separating a permeate from a multicomponent liquid substrate in a reservoir, said process comprising, submerging skein fibers within said substrate unc

In a process for maintaining the outer surfaces of hollow fiber membranes essentially free from a build-up of deposits of particulate material while separating a permeate from a multicomponent liquid substrate in a reservoir, said process comprising, submerging skein fibers within said substrate unconfined in a modular shell, said fibers being securely held in laterally opposed, spaced-apart first and second headers, said fibers having a transmembrane pressure differential in the range from about 0.7 kPa (0.1 psi) to about 345 kPa (50 psi), a total surface area >1 m2, and a length sufficiently greater than the direct distance between opposed faces of said first and second headers, so as to present said skein in a swayable configuration above a horizontal plane through the horizontal center-line of a header; mounting said headers in fluid-tight open communication with collection means to collect said permeate; flowing a fiber-cleansing gas through a gas-distribution means proximately disposed relative to said skein, within a zone near the base of said skein, and contacting surfaces of said fibers with sufficient physical impact of bubbles of said gas to maintain essentially the entire length of each fiber in said skein awash with bubbles and essentially free from said build-up; maintaining an essentially constant flux through said fibers substantially the same as an equilibrium flux initially obtained after commencing operation of said process; collecting said permeate in said collection means; and, withdrawing said permeate, the improvement comprising, introducing a cleansing gas in an amount in the range from 0.47-14 cm3/sec per fiber (0.001 scfm/fiber to about 0.03 scfm/fiber) to generate a column of said bubbles alongside and in contact with outer surfaces of said fibers; deploying said skein fibers within said column in an essentially vertical configuration, with said headers in fixed spaced apart relationship at a fixed distance, said skein having fibers of substantially the same length and from at least 0.1% greater, to about 5% greater than said fixed distance, said fibers being independently swayable from side-to-side within a vertical zone of movement with terminal end portions of individual fibers potted in proximately spaced-apart relationship in cured resin; restricting movement of said fibers to said vertical zone defined by lateral movement of outer fibers in said skein; vertically gas-scrubbing said fibers\outside surfaces with bubbles which flow upward in contact with said surfaces; maintaining said surfaces substantially free from said deposits of particulate matter during a period when specific flux through said fibers has attained equilibrium; and, simultaneously, essentially continuously, withdrawing said permeate while increasing the concentration of said particulate material in said substrate.