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US 5,628,909 AGranted
Membrane filters with corkscrew vortex generating means
AssigneeIsis Innovation Limited
InventorBrian J. Bellhouse
Life of this patent
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AssigneeIsis Innovation Limited
InventorBrian J. Bellhouse
Estimating the term…
A filter comprising a tubular filter membrane (1) within which is mounted a concentric core (2) formed with a helical groove (3) and leaving a gap (G). Fluid to be filtered is passed in the upwards direction into the space between the core (2) and the membrane (1) and thus constrained to move in a helical path within a helical space (8) defined between the groove (3) and membrane (1), with leakage flow (7) through the gap (G) between adjacent turns of the helix. The leakage flow (7) shapes and enhances an already-existing vortex flow within the space (8) and ensures effective scouring of the membrane to prevent build-up of solids on the membrane surface. A version incorporating an externally threaded helical groove is also described. The filter is useful for a wide range of filtration purposes, particularly in ultrafiltration and microfiltration.
A filter comprising a tubular, substantially cylindrical, porous membrane mounted coaxially with and radially spaced from a generally cylindrical profiled surface, which surface is formed with at least one helical groove such that a fluid to be filtered is passed into the filter from one end thereof between the membrane and the profiled surface in a helical flow, and means for inducing or enhancing, in the helical flow of the fluid to be filtered, a corkscrew vortex flow, said means comprising the shape of said groove, when seen in longitudinal cross section, being concave and formed of a substantially continuously curved surface.
A method of filtering a fluid comprising:
A filter comprising a tubular, substantially cylindrical, porous membrane mounted coaxially with and radially spaced from a generally cylindrical profiled surface, said profiled surface having a diameter such as to define a gap between itself and the membrane, and which surface is formed with at least one helical groove, the shape of said groove, when seen in longitudinal cross section, being concave and formed of a substantially continuously curved surface, such that a fluid to be filtered is passed into the filter from one end thereof between the membrane and the profiled surface and flows in a helical path, said gap being such as to cause a leakage flow of fluid between adjacent turns of the helical groove, said leakage flow being operable to induce or enhance, within the helical flow of the fluid to be filtered, a corkscrew vortex flow.
Dependencies are inferred from the claim text.