Corrugated screen filters and related method of fabrication whereby an available filter surface is increased so as to allow an increase a flow capacity of the corrugated screen filter. The corrugated screen filter can comprise a plurality of rods forming a series of alternate and angular ridges and grooves on a surface of the filter screen. The filter screen can be configured to have longitudinal corrugations only on an exterior surface of the filter screen or alternatively, the filter screen can be configured to have longitudinal corrugations only on an interior surface of the filter screen. The alternate angular ridges and grooves can form corrugations in a variety of configurations including, but not limited to, a sinusoidal wave structure, a triangular wave structure, a rectangular wave structure, a trapezoidal wave structure, or the like.

A filter module with a perforated inner tube (20) and a concentric, perforated outer tube (22), forming an interposed annular gap for a filter membrane (10) pleated into folds. The membrane folds (11, . . . ) are of different fold types with differing fold heights, extend from a respective fold edge (111, . . . ) resting against the outer tube towards the inner tube to the respective fold tip (114, . . . ) and are arranged along the circumference of the annular gap as groups of folds (11, . . . ) of different types. Each group has a mating fold (15) which extends from a mating fold edge (151) resting against the inner tube towards the outer tube to the mating fold tip (154). The height of the mating fold is no more than the difference between the width of the annular gap and the height of the fold type with the shortest height of the same group.

The invention features a filtration segment having a top seal, a bottom seal and a primary filter core and the method of filtering with the design of the filtration segment. The primary filter core is operatively coupled to at least one opening which is located either on the top seal or on the bottom seal. The filtration segment also includes one or more interior filters surrounding the primary filter core. Each interior filter includes a filter material surrounding a secondary core which is operatively coupled to at least one opening which is located either on the top seal or on the bottom seal. Each filter may optionally include a retaining medium enclosing the filter material. The filtration segment has one or more layers of an exterior filter media which operatively surround the interior filters and are operatively coupled to the top seal and the bottom seal.

A cylindrical filter element having a central longitudinal axis and filter media including a plurality of radially extending pleats arranged in a pattern that repeats around the central longitudinal axis. Each of the pleats comprises an inner pleat tip, wherein the inner pleat tips of each pattern define an open area that extends along a height of the filter element, and wherein each pattern of pleats comprises a first series of intermediate pleats that descends in length from a major pleat to a minor pleat and a second series of intermediate pleats that ascends in length from the minor pleat to a major pleat of an adjacent pattern of pleats.

A filter module with a perforated inner tube (20) and a concentric, perforated outer tube (22), forming an interposed annular gap for a filter membrane (10) pleated into folds. The membrane folds (11, . . . ) are of different fold types with differing fold heights, extend from a respective fold edge (111, . . . ) resting against the outer tube towards the inner tube to the respective fold tip (114, . . . ) and are arranged along the circumference of the annular gap as groups of folds (11, . . . ) of different types. Each group has a mating fold (15) which extends from a mating fold edge (151) resting against the inner tube towards the outer tube to the mating fold tip (154. The height of the mating fold is no more than the difference between the width of the annular gap and the height of the fold type with the shortest height of the same group.

Corrugated screen filters and related method of fabrication whereby an available filter surface is increased so as to allow an increase a flow capacity of the corrugated screen filter. The corrugated screen filter can comprise a plurality of rods forming a series of alternate and angular ridges and grooves on a surface of the filter screen. The filter screen can be configured to have longitudinal corrugations only on an exterior surface of the filter screen or alternatively, the filter screen can be configured to have longitudinal corrugations only on an interior surface of the filter screen. The alternate angular ridges and grooves can form corrugations in a variety of configurations including, but not limited to, a sinusoidal wave structure, a triangular wave structure, a rectangular wave structure, a trapezoidal wave structure, or the like.

A filter element includes at least first and second opposing pleated media sections and at least first and second support structures supporting, absent an inner liner, the at least first and second media sections and being layered between the at least first and second media sections. In another embodiment, the filter element includes a continuous construction of pleated media forming the first and second opposing pleated media sections, in which the pleats have portions of differing lengths, and a support structure within the interior volume supporting the first and second media sections. The filter element can be in the form of two racetracks, a V-pack, or two V-packs. The racetracks can be polygon shaped.

A filter element for fluids, in particular for hydraulic fluid, has a foldable filter casing (10) with at least one filter layer (18, 20, 22, 24) extending between two end caps (26, 32). To vary in regions the thickness of the filter casing (10), the height (h.sub.1) of each filter fold (12, 44) increases from one end cap (26) to the other end cap (32). Alternatively, with the filter fold height (h.sub.1) being maintained, the outer diameter (40) of the filter casing (10) varies in the direction of one of the end caps (26, 32).

The invention features a filtration segment having a top seal, a bottom seal and a primary filter core and the method of filtering with the design of the filtration segment. The primary filter core is operatively coupled to at least one opening which is located either on the top seal or on the bottom seal. The filtration segment also includes one or more interior filters surrounding the primary filter core. Each interior filter includes a filter material surrounding a secondary core which is operatively coupled to at least one opening which is located either on the top seal or on the bottom seal. Each filter may optionally include a retaining medium enclosing the filter material. The filtration segment has one or more layers of an exterior filter media which operatively surround the interior filters and are operatively coupled to the top seal and the bottom seal.

A device for treating fluid, in particular a filter device, having at least one first (12) and one second tubular element (14) forming an element assembly (10) with each other, wherein the one element (14) is accommodated in the other element (12) forming a flow chamber (33) between the two elements (12, 14) such that a first element (12) is arranged in the direction of the inflow side (29) of a fluid to be treated and a second element (14) is arranged in the direction of the outflow side (31) of the treated fluid in the element assembly (10), and wherein during the fluid treatment, the flow is routed through both elements (12, 14) in succession from the direction of the inflow side (29) towards the outflow side (31), is characterized in that, in relation to a joint viewing direction (P), the first element (12) facing the inflow side (29) at least partially has a uniform or non-uniform con tour and the second element (14) facing the outflow side (31) at least partially has a non-uniform or uniform contour.