Filtration system with anti-telescoping device
A filtration system includes an outer casing that houses a plurality of elongated inner casings, which in turn house a plurality of filters (membranes). The outer casing, inner casings, and filters are disposed relative to one another to provide a three-flow channel system that provides additional feed fluid at one or more of the membrane couplings between membranes of the same inner casing. In preferred systems and methods the feed fluid flow path comprises an annular space between the inner casings and the filters contained in such casings, and in more preferred embodiments the annular space is substantially continuous past multiple filters of the same inner casing. The inner casings may advantageously have openings that fluidly communicate with the lumen of the outer casing, thereby reducing the ratio of couplings relative to the number of filters (the coupling/filter ratio). In especially preferred embodiments the coupling/filter ratio ≦1:2, in more preferred embodiments the coupling/filter ratio ≦1:3, and in still more preferred embodiments the coupling/filter ratio ≦1:4.
1 . A filtration system comprising:
an elongated outer casing defining an outer lumen;
a plurality of elongated inner casings disposed within the outer lumen, each of the inner casings having an inner lumen in which is disposed a filter; and
the outer casing, inner casings, and filters disposed relative to one another to define a feed fluid flow path in which a feed fluid exiting from an upstream filter into a downstream filter is diluted by additional feed fluid.
2 . The filtration system of claim 1 wherein the additional feed fluid passes to the downstream filter by flowing from the outer lumen through an opening in one of the inner casings.
3 . The filtration system of claim 2 wherein the opening is dimensioned to produce a maximum operational pressure drop of about 20%.
4 . The filtration system of claim 1 wherein each of the inner casings contains a plurality of the filters.
5 . The filtration system of claim 1 wherein the plurality of filters in at least one of the inner casings is serially disposed to provide a substantially continuous core space.
6 . The filtration system of claim 6 further comprising a manifold fluidly coupling the inner lumen of each of the inner casings, and another manifold fluidly coupling the core space of each of the inner casings.
7 . The filtration system of claim 6 having opposite ends, and both of the manifolds extending from the same one of the opposite ends.
8 . The filtration system of claim 1 wherein at least one of the inner casings contains a plurality of the filters serially disposed to provide a substantially continuous core space, and wherein a permeate flow path extends through the substantially continuous core space.
9 . The filtration system of claim 8 wherein the serial disposition of the filters in at least one of the inner casings defines a substantially continuous annular space between an inner wall of each of the inner casings and the filters disposed within the inner CD casings.
10 . The filtration system of claim 1 wherein at least one of the filters is spiral wound.
11 . The filtration system of claim 1 wherein at least one of the filters comprises hollow fiber membranes.
12 . The filtration system of claim 1 further comprising an energy recovery device that derives energy from a waste fluid in the waste fluid flowpath.
13 . The filtration system of any one of claim 1 wherein the outer casing is disposed substantially above ground.
14 . The filtration system of claim 1 having a coupling/filter ratio ≦1:2.
15 . The filtration system of claim 1 having a coupling/filter ratio ≦1:3.
16 . The filtration system of claim 1 having a coupling/filter ratio ≦1:4.