Filter apparatus

Claim 2

A filter element for use in a filter having means for providing a reverse flow of fluid through the filter element, said filter element including a unitary, tubular, plastic core having a plurality of continuous external ribs extending longitudinally throughout the length of said core, a head member sealably bonded over the upper end of said core and having a passageway therethrough opening into said core, an imperforate base member sealably bonded over the bottom end of said core, a coarsely perforated plastic sleeve surrounding and tightly fitting over said core from said head member to said base member, said sleeve being bonded to said head and base members, and a fine mesh sleeve removably positioned over said plastic sleeve, said core being essentially imperforate except near the bottom where it is provided with a plurality of radial passageways extending therethrough, whereby liquid passing into the filter element through said sleeves flows downwardly between said ribs along the outside of said core to the bottom thereof, through said passageways into said core and upwardly through the central cavity in said core.

Claim 3

A filter element according to claim 1, wherein said core includes means defining a given number of passageways near said one end for passing air during filling thereof, and means defining a relatively larger number of apertures near said other end for passing the bulk of fluid during the filter operation and during the cake removal operation.

Claim 4

A filter element according to claim 2, wherein said given number is 1, and said larger number of passageways are equally-spaced about the periphery of said core and are arranged in two separate, closely-spaced planes extending in a direction perpendicular to the axis of said filter element, said planes being disposed within a given distance from the outer end of said base member, said given distance being less than 10 percent of the length of said filter element.

Claim 5

A filter element according to claim 2, wherein said core is composed of polypropylene.

Claim 6

A filter element according to claim 2, wherein said coarsely perforated plastic sleeve comprises a grid of tubular construction, said grid consisting of a plurality of first filaments And a plurality of transverse filaments integrally connected at the points of intersection with said first filament to form a seamless tube.

Claim 7

A filter element according to claim 5, wherein said sleeve is composed of polypropylene.

Claim 8

A filter element according to claim 5, wherein said head member has a depending, annular outer wall and includes a centrally-disposed depending plug member tightly fitting into the cavity at said one end of said core so that said core and said sleeve fit snugly between said plug member and the outer wall of said head member.

Claim 9

A filter element according to claim 5, wherein said head member is composed of polypropylene.

Claim 10

A filter element according to claim 7, wherein said base member has an upstanding annular wall and includes a centrally-disposed plug member fitting tightly into said other end of said core, said core and said sleeve being positioned between said plug member and the outer wall of said base member and being bonded thereto such that the filter element is a rigid integral unit.

Claim 11

A filter element according to claim 8, wherein said base member is composed of polypropylene.

Claim 12

A filter element for use in a filter having means for reversing the flow of liquid through the filter element to remove a filter cake deposited thereon, said filter element including a tubular core over which a finely perforated filter cake supporting medium is mounted, the improvement comprising a unitary tubular, plastic core having a plurality of longitudinally extending external ribs, a head member sealably secured by bonding over one end of said core and having an axial passageway therethrough opening into said core, an imperforate base member sealably secured by bonding over the other end of said core, and a coarsely perforated, seamless plastic sleeve surrounding and tightly fitting over said core, said core being provided with a plurality of radial passageways extending therethrough, a tubular connector connecting to said head member and communicating with said axial aperture in said head member, a mounting stud connected to said base member, an elastomeric centrally-apertured head collar surrounding said connector, an elastomeric centrally-apertured base collar sealably surrounding said mounting stud, said collars each having an external, annular peripheral groove, and a pair of cords each arranged in a continuous loop and securing a filter cake supporting medium to said collars, said cords being seated in said grooves of said collars whereby when secured in place, said cords seal said filter cake supporting medium to said collars.

Claim 13

A filter element for use in a filter having means for reversing the flow of liquid through the filter element to remove a filter cake deposited thereon, said filter element including a tubular core over which a finely perforated filter cake supporting medium is mounted, the improvement comprising a unitary tubular, plastic core having a plurality of longitudinally extending external ribs, a head member sealably secured by bonding over one end of said core and having an axial passageway therethrough opening into said core, an imperforate base member sealably secured by bonding over the other end of said core, and a coarsely perforated, seamless plastic sleeve surrounding and tightly fitting over said core, said core being provided with a plurality of radial passageways extending therethrough, a tubular connector connecting to said head member and communicating with said axial aperture in said head member, a mounting stud connected to said base member, an elastomeric centrally-apertured head collar surrounding said connector, an elastomeric centrally-apertured base collar sealably surrounding said mounting stud, said collars each having an external, annular peripheral groove, and a pair of cords each arranged in a continuous loop and securing a filter cake supporting medium to said collars, said cords being seated in said grooves of said collars whereby when secured in place, said cords seal said filter cake supporting medium to said collars.