Filtration apparatus for polymer processing and method

A filtration apparatus for use in polymer processing systems, comprising:

• (a) a housing having an internal bore for directing a polymer flow in a channel oriented transversely to the bore;
• (b) a slide plate for supporting filters, the slide plate moveable through the channel and across the bore and comprising an upstream slide plate surface and a downstream slide plate surface;
• (c) an upstream seal ring annularly disposed about a central bore axis of the bore and comprising first and second opposing upstream seal surfaces, the first upstream seal surface facing downstream for sealably contacting the upstream slide plate surface, and the second upstream seal surface angled with respect to the bore axis;
• (d) a plurality of ring segments arranged in contact with each other to form a segmented ring annularly disposed about the bore axis, each ring segment comprising a tapered ring surface generally complementarily angled relative to and sealably contacting the second upstream seal surface;
• (e) a downstream seal ring annularly disposed about the bore axis, the downstream seal ring comprising a first downstream seal surface facing upstream for sealably contacting the downstream slide plate surface, and an opposing second downstream seal surface;
• and
• (f) an adjustment ring annularly disposed about the bore axis and sealably contacting the second downstream seal surface, the adjustment ring being axially adjustable along the bore for biasing the downstream seal ring against the slide plate.

A filtration apparatus for use in polymer processing systems, comprising;

• (a) a housing having an internal bore for directing a polymer flow in a channel oriented transversely to the bore;
• (b) a slide plate for supporting filters, the slide plate movable through the channel and across the bore and comprising an upstream slide plate surface and a downstream slide plate surface;
• (c) an upstream seal ring annularly disposed about a central bore axis of the bore and comprising first and second opposing upstream seal surfaces, the first upstream seal surface facing downstream for sealably contacting the upstream slide plate surface, and the second upstream seal surface angled with respect to the bore axis;
• (d) a plurality of ring segments arranged in contact with each other to form a segmented ring annularly disposed about the bore axis, each ring segment comprising a tapered ring surface generally complementarily angled relative to and sealably contacting the second upstream seal surface;
• and
• (e) a connector ring annularly disposed about the bore axis and sealably contacting the ring segments, wherein the ring segments are axially interposed between the upstream seal and the connector ring.

A method for sealing a filtration apparatus to reduce leakage and degradation of polymer flowing therethrough, comprising the steps of:

• (a) placing an annular upstream seal ring in a polymer flow bore of a filtration apparatus, wherein the upstream seal ring is disposed upstream from a channel oriented transversely to the bore, and the upstream seal ring comprises a first upstream seal surface generally facing the channel and an opposing second upstream seal surface angled with respect to a central bore axis of the bore;
• (b) sealing an annular segmented ring against the upstream seal ring, the segmented ring comprising a plurality of ring segments fitted together, wherein each ring segment comprises a tapered ring surface generally complimentarily angled relative to the second upstream seal surface, and each tapered ring surface contacts the second upstream seal surface;
• and
• (c) flowing a polymer through the bore at a polymer flow pressure, whereby the polymer imparts force components directed radially outwardly relative to the bore axis to each ring segment, and each ring segment imparts an axially downstream directed force component against the second upstream seal surface.