Self-sealing filter tube

A method of sealing a filter tube in a filter tube cartridge, the cartridge comprising:

• a. a support core characterized by an axial flow passage therethrough, and further characterized by a plurality of flow passages on the cylindrical wall of the core, which flow passages provide communication between the axial flow passage and the outer wall of the support core;
• b. a filter tube adapted to be placed onto the support core in a close-fitting relationship surrounding the [suppore] support core;
• and
• c. end elements positioned at each end of the support core, the end elements having outwardly extending flanges thereon extending outwardly from the surface of the core at least the thickness of the filter tube, which method comprises:
• i. placing over the support core a semirigid, cylindrical, unitary, porous, filter tube composed of a plurality of overlapping nonwoven filters having interstices therebetween to define the porosity of the tube, the fibers containing at the junction of the fiber crossovers a hardened material to provide a semirigid, self-supporting structure throughout the body of the filter tube, the fibers having an average diameter of about 0.001 to 10.0 microns, the fibers at the region about the peripheral edge of each end of the tube adapted to be compressed together on the application of an axial force;
• and
• ii. applying an axial force against the fibers at the peripheral edges at each end of the filter tube by the axial movement of at least one of the end elements, so as to press the facing surfaces of the flanges against the edges of the filter tube and compress the fibers together at such edges and across the entire edge width of the fiber tube and adjacent the immediate region of the facing surfaces to provide a peripheral fluid-tight seal between the facing surfaces and the body of the filter tube.

A cartridge filter, which filter comprises in combination:

• a. a semirigid, cylindrical, porous filter tube, the tube composed of a plurality of overlapping nonwoven fibers having an average diameter of from about 0.001 to 10.0 microns, the fibers having interstices therebetween to define the porosity of the tube, the fibers containing at the junctions of the fiber crossovers a hardened material to provide a semirigid, self-supporting structure throughout the body of the filter tube, the fibers at the peripheral edge of each end of the filter tube adapted to be compressed together into a sealing relationship upon the application of an axial force;
• b. elements positioned at each end of the filter tube, the elements having flanges extending outwardly at least the thickness of the filter tube, at least one of said elements characterized by an aperture therein to permit a fluid to be introduced into or withdrawn from the interior of the filter tube, the flanges each having a facing surface which abuts each edge of the ends of the filter tube, at least one of which end elements is adjustable for axial movement in relationship to the filter tube, and at least one of each end elements is adapted to be removed to permit the removal and replacement of the filter tube, the fibers across the entire edge width of the filter tube and adjacent each facing surface compressible about the periphery by axial force due to the axial movement and position of the end elements, the fibers compressible together by being forced against the facing surface of each flange in the immediate peripheral region adjacent to the facing surface of each flange to provide a peripheral fluid-tight seal between the facing surfaces and the body of the filter tube;
• and
• c. means to move axially at least one of the end elements in relationship to at least one end of the filter tube, whereby an axial force may be applied to compress the fibers together into a fluid-tight seal to the end element.

A method of sealing a filter tube in a filter tube cartridge, the cartridge comprising:

• a. a filter tube;
• b. end elements positioned at each end of the filter tube, the end elements having flanges with facing surfaces extending outwardly from the surface of the core at least the thickness of the filter tube, which method comprises,
• i. providing a semirigid, cylindrical unitary, porous filter tube composed of a plurality of overlapping nonwoven fibers having interstices therebetween to define the porosity of the tube, the fibers containing at the junction of the fiber crossovers a hardened material to provide a semirigid, self-supporting structure throughout the body of the filter tube, the fibers having an average diameter of about 0.001 to 10.0 microns, the fibers at the region about the peripheral edge of each end of the tube adapted to be compressed together on the application of an axial force, and
• ii. applying an axial force against the fibers at the peripheral edges at each end of the filter tube by the axial movement of at least one of the end elements, so as to press the facing surfaces of the flanges against the edges of the filter tube and compress the fibers together at such edges and across the entire edge width of the fiber tube and adjacent the immediate region of the facing surfaces to provide a peripheral fluid-tight seal between the facing surfaces and the body of the filter tube;
• and
• c. means to move axially at least one of the end elements in relationship to at least one end of the filter tube, whereby an axial force may be applied to compress the fibers together into a fluid-tight seal to the end element.