Cross-flow filtration device with filtrate conduit network and method of making same

A cross-flow filtration device for receiving a feed stock at a feed end face and for separating the feed stock into filtrate and retentate, comprising:

• a) a structure containing a substantially parallel arrangement of a plurality of monolith segments of porous material, each segment containing a plurality of passageways extending longitudinally from the feed end face to a retentate end face of the structure through which the feed stock flows to pass retentate from the device, the surface area of the passageways being at least 100 square feet per cubic foot of the structure;
• b) a filtrate collection zone external to the structure disposed along the side of the structure and further including a barrier means, disposed at the feed and retentate ends of the structure, for inhibiting direct passage of the feed stock and retentate into the filtrate collection zone;
• c) a filtrate conduit network within the structure for carrying filtrate toward the filtrate collection zone, the filtrate conduit network providing paths of lower flow resistance than that of alternative flow paths through the porous material;
• d) the filtrate conduit network containing an intersegment filtrate conduit defined by the arrangement of the monolith segments;
• e) the filtrate conduit network further containing at least one intrasegment filtrate conduit within at least one monolith segment, the intrasegment filtrate conduit comprised of a plurality of longitudinal chambers which extend substantially along the entire length of the monolith segment, the chambers being transected by a transverse channel which directs filtrate into the inter-segment filtrate conduit or toward the filtrate collection zone, and the intrasegment filtrate conduit communicating with the intersegment filtrate conduit or otherwise directing filtrate toward the filtrate collection zone;
• and
• f) the filtrate conduit network being isolated from the passageways at both end faces of the structure and at least some of the passageways being separated from the filtrate conduit network by intervening passageways.

A method of forming a filtrate conduit network in a structure containing a substantially parallel arrangement of a plurality of monolith segments of porous material, each segment containing a plurality of passageways extending longitudinally from a feed end face to a retentate end face, the surface area of the passageways being at least 100 square feet per cubic foot of the structure, comprising:

• a) arranging the monolith segments to form an intersegment filtrate conduit in the space separating the segments, the intersegment filtrate conduit providing a flow path of low resistance for filtrate flow toward a filtrate collection zone;
• b) within at least one selected segment, establishing an intrasegment conduit by selecting a plurality of passageways as filtrate chamber passageways to distribute the filtrate chamber passageways among the nonselected passageways in the selected segment to provide low pressure drop flow paths from the nonselected passageways through the porous material to nearby filtrate chamber passageways, and establishing at least one filtrate channel in the selected segment which transects the filtrate chamber passageways, the channel providing a flow path of low resistance for filtrate flow toward the filtrate collection zone or toward the intersegment conduit;
• c) sealing the intersegment filtrate conduit at the end faces of the structure to inhibit direct passage of fluid into the intersegment filtrate conduit at the end faces;
• and
• d) sealing all filtrate chamber passageways and filtrate channels exposed at the end faces of the structure to inhibit direct passage of fluid into the intrasegment filtrate conduit.