Patent ID: 8236177

Claim:
A spiral wound filter, comprising: a collection tube having a first end and a second end, and defining a longitudinal axis; at least one membrane wound around said collection tube, said membrane defining a feed surface and a permeate surface; a proximal end adjacent to said collection tube; a distal end opposite the proximal end; a feed inlet end adjacent the first end of the collection tube; a concentrate outlet end adjacent the second end of the collection tube; a width dimension from the feed inlet end to the concentrate outlet end; and a length dimension from the proximal end to the distal end; a layer of feed channel spacer material adjacent to and coextensive with the feed surface, and barriers formed along said feed channel spacer layer material which constrain the flow of fluid through said feed channel spacer layer material to a labyrinth fluid flow path from a feed inlet opening at the feed inlet end to a concentrate outlet opening at the concentrate outlet end, said labyrinth fluid flow path being substantially longer than the width dimension.