Patent ID: 8640884

Claim:
A fluid treatment arrangement comprising: a hollow core assembly having an interior and an axis; first and second adjacent fluid treatment elements mounted along the core assembly, the first fluid treatment element being axially separated from the second fluid treatment element and defining a space between them, wherein each fluid treatment element includes a ribbon which has a permeable fluid treatment medium and is spirally wound in a plurality of windings to define a generally disk-shaped body having a radial dimension, a first end surface on one side of the body, a second end surface on the other side of the body, and an outer rim, wherein an end surface of each fluid treatment element opens directly onto the space, wherein the space extends between the first end surfaces of the first and second fluid treatment elements along at least about 85% of the radial dimension of the first and second fluid treatment elements and is substantially free of structure, wherein the ribbons of the first and second adjacent fluid treatment elements are separate from one another, each ribbon having opposite major surfaces and being free of any through holes or slots extending between the opposite major surfaces, and wherein the first end surfaces of the first and second fluid treatment elements have no points of contact between them; and a fluid pathway which extends between the first and second end surfaces of each fluid treatment element generally edgewise through the permeable fluid treatment medium to or from the space.