WO2018215985A1

WO2018215985A1 - Filter element

Info

Publication number: WO2018215985A1
Application number: PCT/IB2018/053744
Authority: WO
Inventors: Charles Ramberg
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-05-25
Filing date: 2018-05-25
Publication date: 2018-11-29
Anticipated expiration: 2019-11-25
Also published as: WO2018215985A4

Abstract

A filter plate fabricated from porous polymer, ceramic or metal is described. Ridged tapes are sandwiched between porous flanges to form a multiaxial web between the flanges. A network of support points between two opposing filtration faces creates a web that stiffens and supports the flanges multiaxially. Longitudinally oriented ridges within the web are oriented in at least two directions, increasing stiffness in at least two directions. A filter plate may be fabricated from one or more ridged tapes. A facedown flange may be laid up onto a faceup flange to form a sandwich structure, with the ridge(s) connecting the flanges to the web between the flanges.

Description

FILTER ELEMENT

BACKGROUND

1. Technical Field

[0001] The present invention relates generally to filtration, and more particularly to liquid filtration membranes supported by porous substrates, such as porous ceramic membranes.

2. Description of Related Art

[0002] Membrane filters elements are used for filtration, such as water filtration. A porous (polymer, metal, or ceramic) substrate supports a porous membrane, which typically has a smaller median pore size than the substrate (e.g., less than 1 micron vs. tens of microns). Ceramic membrane filters are often fabricated by stamping or casting, which may not work for particularly thin filtration membranes.

[0003] Ceramic substrates for catalytic converters, diesel particulate filters, and the like are typically fabricated by extrusion. Channels are extruded around a core in the extrusion mold, and so the extrusion direction defines the channel direction. Extrusion enables the formation of thin channel walls - below 1 mm, including below 500 microns, even below 200 microns. Channels in an extruded body are defined by the extrusion direction, which defines the direction through which fluid then flows through the substrate. Extruded bodies are mechanically anisotropic; the mechanical properties are different in the extrusion direction than orthogonal to the extrusion direction.

[0004] Ceramic filters may include a filtration membrane on the surface of the substrate. Inasmuch as the filtration properties are governed by the membrane' s properties, one primary purpose of the substrate is to support the membrane during fabrication, assembly, and use. For a given filtration requirement (e.g., % of removal of a particular size of particles, minimum particle size removed, filtration rate, pressure drop), it is typically desirable to maximize membrane area (per unit volume of filter) and permeation rate (per unit volume of filter). Permeability is typically increased with percent porosity and pore size, typically at the expense of degraded mechanical properties.

[0005] Ceramic filtration membranes are brittle, porous, and typically thin (10 microns or less). Thus, the structural properties of the substrate supporting the membrane are important, especially during processing of the membrane (burnout, sintering) and assembly. Substrate porosity (median pore size and % porosity) should be large enough that the pressure drop across the substrate (from the backside of the membrane) does not appreciably limit permeate flow rate, but increasing substrate porosity reduces stiffness and strength. As a result, a substrate that supports a thin membrane is typically many times thicker than the membrane itself. As a result, typical prior art substrates typically contribute to pressure drop, notwithstanding that the membrane is doing the filtration.

[0006] Planar ceramic filters for liquid filtration are often extruded to create open channels within the substrate. The extrusion direction defines the channel longitudinal direction. The substrate may be relatively strong against bending in one direction (e.g., lifting up on the leading and trailing edges as defined by the extrusion direction) but are weak in other directions (e.g., lifting up on the sides as defined by the extrusion direction).

[0007] FIG. 0 illustrates an extruded substrate typically used for liquid filtration. In substrate 001, open channels 002 within the substrate allow fluid to flow in a flow direction typically defined by the extrusion direction 003. When adjacent channels are spaced far apart, the substrate may be relatively stiff against a bending 004 aligned with the channels, as illustrated by loads 004' . However, spacing channels far apart reduces filtration performance into or out of the channels (through the substrate body itself). Additionally, the substrate is not stiff against a bending 005 across the channels, as illustrated by loads 005' . Lifting the substrate by the sides (with respect to the extrusion direction) may easily damage the substrate.

[0008] Permeate flux between the channels and exterior of the substrate is typically concentrated at the portion of the substrate where the distance between the channel surface and outside surface is smallest. Permeability of these thin portions is increased by decreasing minimum thickness 006, but mechanical resistance to bending 005 is correspondingly reduced by decreasing minimum thickness 006. For a very thin minimum thickness 006 between the exterior and interior of the channels, the thinnest "roof portion of the channel (above the midpoint of the channel) may deform or collapse during processing (e.g., after binder burnout but before sintering begins).

[0009] Forces applied to the substrate during fabrication, assembly, and use may break the substrate (e.g., opening a crack in the substrate along the channel top or bottom). Typically, this crack opens along the surface loaded in tension (e.g., the middle -bottom for loads 005' in FIG. 0). To prevent breakage, prior art substrates are typically maintained at a minimum thickness 006 between the channel and the outer surface of the substrate that is at least 1 cm. Such thick substrates reduce permeation rates. It would be advantageous if a substrate were to combine a high permeation rate with improved mechanical properties.

[0010] Artisans have attempted to develop porous ceramic filtration substrates. EP publication no. 2 543 420 describes a method for making a stamped substrate.

SUMMARY

[0011] A filter substrate may comprise a plate having two opposing porous faces, described herein as flanges. The porosity of the flanges is typically chosen according to a desired filtration specification (e.g., permeate flow rate, membrane porosity, filtered contaminant particle size, and the like). The flanges are connected by one or more ridges or ribs, described herein as a web. The web defines an open inner volume between the flanges within which fluid (e.g., permeate) may flow. The web typically includes longitudinal portions of ridges aligned in at least two different lateral directions with respect to plate thickness. As such, the substrate is multiaxially reinforced.

[0012] Multiaxial reinforcement stiffens the plate laterally over a range of directions (e.g., against bending around the plate width, such as drumhead bending). As compared to prior substrates, the multiaxial web may improve manufacturability, stiffness, and quality. A much thinner porous flange may be used (to obtain equivalent plate stiffness), significantly improving permeate flux. The substrate may have higher permeation rates (at given median pore size and % porosity) yet with increased stiffness and strength and decreased mass. A plate comprising a multidirectional web between opposing flanges may yield a structure that combines sufficient macroscopic thickness for handling and assembly with low substrate mass and small thicknesses of the permeation walls. For substrates having membranes disposed on the flanges, the multiaxial web may provide for improved support for the membrane while reducing the pressure drop associated with flow through the flange itself. Because the filter plate is relatively stiff (notwithstanding that the flanges are thin), a deposited membrane may have a reduced tendency to crack, delaminate, and/or otherwise fail.

[0013] The claims summarize. In an embodiment, a multiaxially reinforced filter plate comprises a first porous ceramic flange (e.g., having a thickness below 5mm, at least 30% porosity, a median pore diameter below 50 microns, such as below 20 microns) and having what will ultimately be an inside surface and an outside surface of the filter plate. The plate comprises a second porous ceramic flange (e.g., having a thickness below 5mm, at least 30% porosity, a median pore diameter below 50 microns) and having corresponding inside surface and outside surface. A multiaxial web comprising one or more ridges connects the inside surfaces of the flanges to form the filter plate. The web has one or more ridges for which at least a portion of a ridge extending in a first long.direction (of the ridge) is aligned in a first lateral direction of the plate (e.g., orthogonal to a platethickness of the plate), and at least a portion of a ridge extending in a second long.direction aligned in a second lateral direction different than the first lateral direction, yielding multidirectional alignment of longitudinal ridge directions with respect to plate width, resulting in multiaxial reinforcement of the plate.

[0014] The web typically has distances between adjacent ridges and a webheight large enough to create channels between the flanges that are sufficient to transport an expected permeate flux through the flanges without causing substantial pressure drop due to the channels themselves. The webheight is designed to be large enough (according to flange thickness and plate size) to stiffen and strengthen the plate, such that the web and flanges behave as a beam. As compared to prior plates, a tall webheight, narrow ribs, wide spacing between ribs, and multiaxial reinforcement of the flanges may increase strength and stiffness while reducing weight and increasing permeability, particularly for thin flanges (e.g., below 3mm thick, including below 800 microns thick). Typically, webheight is at least 50% as large, including at least as large, particularly at least twice as large, as the thickness of at least one flange. Webheight may be over 3x, including over 5x, including over lOx flange thickness.

[0015] For flanges made from extruded tapes (and/or other bodies having inherently uniaxial ridges) multiaxial reinforcement stiffens the plate in directions other than a particular tape's extrusion direction. As such, extruded tapes may be stacked or rolled to yield improved (e.g., less anisotropic) mechanical properties.

[0016] One or more open channels between the flanges may form a network to provide for fluid communication between the inside surfaces of the flanges an edge of the plate, particularly to an open portion of the edge, particularly wherein the channels have a cross-section-area greater than lmm^A2, including above 4mm^A2, including at least 9mm^A2. For some plates, channel cross-section area may be at least lcm^A2, including at least 3cm^A2, including at least 9cm^A2.

[0017] The flange may be fabricated as a tape (e.g., via tape casting) and have ridges deposited thereon (e.g., via an injector, 3D printer, and the like). A ridge may be deposited onto a flat tape (e.g., a green tape) then sintered. The flange may be extruded as a ridged tape, with the ridges integrally formed with the tape during extrusion. Integral ridge formation (e.g., via extrusion) may improve the integrity of the tape (green and fired), and may ease handling of the tape, alignment and positioning of tapes against each other, and the like. In some cases, a tape is scored, stamped and/or rolled to form ridges on the surface of the green tape. The ridges on one flange are typically bonded to either the facing flange or to the ridges on the facing flange, forming a multiaxial web that reinforces the flanges.

[0018] According to a desired combination of flange permeability (flange thickness and porosity) and plate stiffness, webheight may be chosen such that the flanges are sufficiently strengthened (by the web) and a desired flow rate within the channels (to not yield appreciable pressure drop) is achieved. Open channels typically impede flow less than permeation (through a porous flange), and so channel area may be relatively small yet still yield sufficient permeate removal. As such, webheight may be largely influenced by the mechanical requirements on the plate itself.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 0 illustrates an extruded substrate.

[0020] FIGS. 1 A and IB are schematic illustrations of a ridged tape, per an embodiment.

[0021] FIG. 2 is a schematic illustration of portions of a plate, per an embodiment.

[0022] FIG. 3 is a schematic illustration of a filter plate having a multiaxial web, per an embodiment.

[0023] FIG. 4A is a schematic illustration showing an exploded view of a filter plate having a multiaxial web, per an embodiment.

[0024] FIG. 4B is a schematic illustration of a cross section of a filter plate having a multiaxial web, per an embodiment.

[0025] FIGS. 5-8 are schematic illustrations of a filter plate having a multiaxial web, per various embodiments.

[0026] FIG. 9 is a schematic illustration of certain aspects of a filter plate having a multiaxial web and coated with a membrane, per an embodiment.

[0027] FIG. 10 is a schematic illustration of a filtration system, per an embodiment.

[0028] FIG. 11 is a schematic illustration of an extrusion process to fabricate a ridged tape, per an embodiment.

[0029] FIG. 12 is a schematic illustration of an exemplary extrusion die, per an embodiment. [0030] FIGS. 13-16 are schematic illustrations of exemplary synthesis processes, per various embodiments.

DETAILED DESCRIPTION

[0031] FIG. 1 A is a schematic illustration of a ridged tape, per an embodiment. A ridged tape may be stamped and/or cast. Advantageously, a ridged tape may be extruded (e.g., from ceramic or metal or polymer). The viscosities and pressures of typical extrusion may enable the use of particularly thin flanges, tall ridges, and/or relatively large spacing between ridges. Extrusion may be used to fabricate relatively large tapes (e.g., more than 0.5m, including over lm wide, and over 1 meter long). A ridged tape having unidirectional ridges is typically "uniaxially" reinforced in a direction aligned with the extrusion direction.

[0032] Ridges may connect two or more tapes, forming "ribs" between the tapes, with open channels between the ribs. The open channels offset the flanges, increasing the strength and stiffness of the "sandwich" of tapes and allowing for relatively unimpeded fluid flow between the tapes. By extending portions of the ribs in at least two different lateral directions, a tape may be multiaxially reinforced.

[0033] While not obvious, it is illustrative to describe the functionality of various substrate components using nomenclature for structural steel I-beam used in buildings (and so various aspects have been described herein using this nomenclature). The opposing thin, flat "tape-like" substrate portions are described as flanges, which are connected by ridges destined to form a web between opposing flanges, reinforcing the flanges against bending in the respective longitudinal directions of the web. Connected flanges form a plate, such that the porous flanges (spaced apart by the web) may filter a fluid as it passes through the flanges (and if present, membranes). By implementing a multiaxial network of ridges with different longitudinal directions, the relatively poor mechanical properties of a thin, porous ceramic tape may be mitigated by implementing the design advantages of a multiaxial web connecting two opposing porous flanges. Open fluid communication between the inside surfaces of the flanges and the edge of the plate results from a combination of a multiaxial web with a contiguous network of interconnected channels, facilitating permeate flow between the interior surfaces of the flanges and the edge of the plate.

[0034] Ridged tape 100 comprises a porous flange 120 (the flat "tape-like" portion) and one or more ridges 110. Flange 120 is designed to filter a contaminant from a fluid stream (using or without a membrane), and has a mean pore diameter, pore size distribution, and % porosity chosen according to the contaminant and fluid (and if present, membrane properties). In an embodiment, flange 120 has a median pore diameter below 50 microns, including below 25 microns, including below 15 microns, and between 20 and 80% porosity, such as 30-70% porosity, including 35-65% porosity. Ridges may be fabricated from the same or different material as the flanges. In some cases, the ridge and flange have substantially equivalent porosity. Ridges may have higher or lower porosity than the flange. Flange 120 has a thickness 122 chosen according to the mechanical and permeation requirements of the application (e.g., whether or not the flange supports a membrane, distance between ridges, ridgewidth, pressure across flange during use, and the like). A thicker flange is typically stronger (e.g., capable of spanning a larger distance between ridges). A thinner flange is typically more permeable. Thus, flange dimensions, ridge width, and inter-ridge spacing are typically designed together. In an embodiment (e.g., for wastewater or produced water filtration), flange thickness 122 may be at least 0.1mm and below 9mm, including 0.15 to 5 mm, including about 0.5-3mm. A flange thickness may be between 0.3mm and 6mm, including between 0.4mm and 4mm. In an embodiment, a plate (e.g., having a thickness below 1cm, particularly below 7mm) has at least one flange having a thickness that does not exceed 2mm, particularly below 1mm. An exemplary ridgewidth is below 4mm, including below 2mm.

[0035] For descriptive convenience, ridged tape 100 is described with an inside surface 130 (e.g., destined to be at the interior of a filter plate) and an outside surface 140. Fluid may flow from outside the plate to the inside (permeate inside/retentate outside) or vice versa. If desired, a membrane may be disposed on the inside and/or outside.

[0036] Ridged tape 100 includes one or more ridges 110 having a long.direction 114 in which the ridges extend longitudinally (with respect to ridge dimension) and laterally (with respect to flange or plate thickness). For an extruded tape, long.direction 114 may be defined by the extrusion direction at the time of extrusion of that portion. Ridges 110 have a ridge.height 112 sufficient to define one or more open channels 150 between flanges through which fluid (e.g., permeate) may flow. A typical ridge.height 112 is up to about 1 cm, including about 1-8 mm, such as about 2-5mm. Ridge height may be larger than 1cm or below 1mm. A channel width 152 may be chosen according to an expected flange thickness (thicker flanges span wider channels) and pressure drop across the flange (e.g., bending moment imparted to the flange). A channel 150 typically has a channel width 152 (between ridges) up to about 2 cm, including below 15 mm. A channel width is typically at least 0.5 mm, including at least 1 mm, including about 2-12 mm, including 3-8 mm. A ridge.width 111 of the ridge may be chosen according to the ridge.height and inter-ridge distance, particularly according to the stiffness of the extrusion paste (a stiffer resting paste requires higher extrusion pressure, but enables a thinner ridgewidth if it can be extruded). A typical ridge.width 111 may be below 1 cm, including 0.1- 7mm, including 0.5-5 mm. Ridge.width 111 may be between 0.5 and 2mm (e.g., for a flange thickness below 2mm. Ridges are typically taller than the flange is thick, yielding a web that is at least twice the flange thickness. Adjacent ridges may be spaced by a distance that is greater than the flange thickness, including 2x, 3x, or even 5x the flange thickness to form channels. In an embodiment, a ridged tape comprises a porous flange (e.g., 25%-75% porosity), particularly ceramic, having a thickness below 5mm (e.g., below 2mm), and one or more ridges having a ridge height that is at least twice as large as the thickness of the flange. An exemplary tape has a flange that is between 0.3 and 0.8 mm thick, with ridge.width 111 between about 0.8 and 1.5mm, and channel width 152 from about 3 to 9 mm.

[0037] FIG. IB is a schematic illustration of a ridged tape, showing relevant directions for plate assembly. A ridge 110 includes a long.direction 114 that stiffens the flange in long.direction 114. A height 230 of the tape (e.g., that ultimately defines a thickness of the filter plate) may be used to define one or more lateral directions 210, 210' of the tape (orthogonal to the height 230). In FIG. IB, the illustrated portions of the ridges 110 are aligned with their long. directions 114 parallel to a first lateral direction 210, thus ridges 110 stiffen the flange against bending in this direction. In this example, the ridges do not extend longitudinally in second lateral direction 210', and so (prior to stacking/rolling) the flange's stiffness/strength in second lateral direction 210' is governed by the properties and dimensions of the flange 120 itself. Ridges providing longitudinal reinforcement are typically several times longer than they are wide, such as at least lOx longer, including lOOx longer. For a ridge.width 111 of a few mm, ridges are typically at 1 cm long, including at least 10cm long. Ridges may extend longitudinally over virtually the entire lateral dimension of a filter plate (e.g., tens of cm, including over lm).

[0038] It may be advantageous to fabricate a filter plate from two separate tapes, which are then stacked or rolled to form the plate. A tape having ridges may be stacked against a flat tape and/or another tape having ridges. By fabricating a ridged tape with its outside surface 140 facing downward (completely supported from below), a very thin flange may be fabricated and supported (e.g., after extrusion, during drying, during firing, after firing). With no portion of the flange "hanging" above an open channel (as with an extruded substrate having contiguous channels, with a extruded "ceiling" over an open channel), support for the entire flange may enable formation of very thin flanges. The flange may lay flat and supported until it is strong enough (e.g., after drying and/or after sintering) to be fabricated into a plate.

[0039] FIG. 2 is a schematic illustration of portions of a filter plate, per an embodiment. FIG. 2 illustrates the portion using nomenclature previously used for steel I-beam structures. Opposing flanges 220/220' have respective flange thicknesses 222 and are connected by a web 210 having a webheight 212 and webwidth 211. The web between the flanges increases beam stiffness in the lateral direction (of the flanges) with which the web is aligned. A relatively large webheight 212 (ridge.height 312, FIG.3) compared to the webwidth 211 (ridge.width 111, FIG.IA) yields a stiff structure that still has a relatively large inner surface area of the flange in open communication with the edge. Thus, the effective permeation area (through the thinnest portion of the flange) may be maximized for a given plate stiffness.

[0040] FIG. 3 is a schematic illustration of a filter plate having a multiaxial web, according to some embodiments. In this example, plate 300 comprises two ridged tapes 100, 100' (stacked against each other), with their respective ridges 110/110' connected to form a multiaxial web 310 within the interior of the plate. A first ridged tape 100 has a "face-down" flange 120 and ridges 110 extending in a first long.direction 114 that is aligned with a first lateral direction 210 of the plate. A second ridged tape 100' has a "face-up" flange 120' and ridges 110' extending in a second long.direction 114' that is aligned with a second lateral direction 210' of the plate. By orienting at least a portion of the ridges in at least two substantially different lateral directions (in this case, orthogonal), the plate may be stiffened in at least those directions, and is thus multiaxially reinforced, as opposed to e.g., a "uniaxially reinforced" extruded substrate.

[0041] To increase shear resistance, ridges 110 on a first tape 100 are typically bonded to ridges 110' on the second tape 100' at bondpoints 510 (e.g., by sintering the ridges, gluing the ridges, and the like). Bondpoints 510 may also bond the ridges of one tape to the flange of the facing tape (e.g., forming lines of bondpoints).

[0042] In this example, the ridges of the respective tapes are bonded at bondpoints 510, yielding a multiaxial web 310. Because the ridges are aligned in at least two different directions, multiaxial web 310 reinforces plate 300 in more than one lateral direction 210/210'. Typically, at least a portion of the long.direction 114 of one ridge differs from the long.direction 114' of the other ridge by at least 10, including at least 20, including at least 30 degrees, and up to about 90 degrees (e.g., at about 45 degrees). The multiaxial web connecting the opposing flanges 120/120' may be formed by one ridge (e.g., having a range of curves and/or angles) and/or by a plurality of ridges. As opposed to uniaxial reinforcement, such multiaxial reinforcement stiffens the flange over a range of directions. While the flange itself is particularly stiffened in the direction of ridge alignment, the multiaxial web of the resulting plate may yield significant stiffening in other lateral directions (e.g., to bending at 45 degrees to the ridges in FIG. 3).

[0043] The ridges may form a network of open channels 150, within which fluid may flow relatively unimpeded (e.g., at a much higher rate than permeation through porous flange material). The channels provide fluid communication between the inside surfaces 130 (FIG. 1) of the flanges and an edge of the filter plate. In an "outside-in" configuration, the flanges filter contaminants from an exterior fluid stream, and the permeate flows from the inside surfaces of the flanges to the edge via channels 150, where it exits the plate. The dimensions of the channels are chosen according to an expected permeation rate (e.g., so the channel flow rate does not impede total flux). A typical channel cross-sectional-area is at least 1mm, including at least 5mm, including at least 8mm, including above 1cm, including above 10cm for very large plates. The aspect ratio of the channel may be chosen according to the relative flow rates through the flanges vs. through the channels (e.g., a 3x3 mm channel vs. a 2x5mm channel). A plate may have one (angled/curved) channel and/or a plurality of channels.

[0044] Webheight 312 of the multiaxial web 310 and the thicknesses 122/122' of flanges 120/120' yield a plate thickness 330 of the plate (typically aligned with height 230 of the corresponding tapes, FIG. IB). To minimize fabrication expenses and maximize filtration system performance, it is typically advantageous to make plate thickness 330 as small as possible while fulfilling serial flux requirements through the flanges and channels. However, decreasing plate thickness 330 typically degrades mechanical properties of the plate (making fabrication and handling more difficult). A multiaxial web connecting relatively thin flanges enables the fabrication of thin, yet mechanically robust filter plates. By keeping the web's ridge. width 111 low (FIG. 1A), relatively little of the flange backside surface needs to be used by the flange, leaving a relatively large portion of the flange open for permeation. For some filters, a typical plate thickness 330 is below a few cm, including below 1 cm, particularly below 7mm. A plate may have a plate thickness below 5 mm. A typical plate thickness is at least 2mm, such as 3-9 mm, including about 4-8 mm. For a larger plate, plate thickness could be up to 20cm, including about 1-10 cm. [0045] The multiaxial web 310 may have a webheight 312 that is at least 50% of (and typically larger than) the thickness 122 of at least one (typically both) of the flanges 120/120' .

Webheight 312 may be more than twice as large as flange thickness 122, including at least 3x, or even at least 4x flange thickness 122.

[0046] A flange typically has a thickness up to about 4mm. In an embodiment, the flange is from 1-4 mm thick, including below 3mm thick. A flange may be from 100 to 800 microns thick. The ridges may be approximately 0.5 to 10 mm wide, including about 0.8 to 9mm, including about 1-5 mm wide. A channel width may be at least 2mm. A channel width may correspond to spacing between adjacent ridges on the same flange may be at least 2mm, including about 3mm-20mm, including about 4- 15mm. A webheight may be from about 3mm-25mm, including about 4mm-20mm, particularly 5- 15mm. In an embodiment, the flange is from 0.2-2 mm thick, including from about 0.3-0.8mm thick. The ridges may be approximately 0.3 to 5 mm wide, including about 0.4 to 4mm, including about 0.5 - 1.5 mm wide. A channel width may correspond to spacing between adjacent ridges of about 2mm- 10mm, including about 4-9 mm. A webheight may be from about 2mm- 10mm, including about 3mm- 9mm. In an embodiment, both flanges have a thickness below 2mm, the ridge. width of the ridges does not exceed 3mm, and the webheight is at least 4mm, which may yield an advantageous combination of mechanical strength and high permeability.

[0047] In an embodiment, two ridged tapes are fabricated (e.g., extruded) with their to-be- outside surfaces face down, then one is flipped over on top of the other (bringing their respective ridges together) and they are attached (e.g., sintered, glued, or otherwise bonded) to form a sandwich. In an embodiment, a first flange is fabricated from a first ridged tape, a second flange is fabricated from a second ridged tape, and the flanges are stacked together with their ridged sides facing each other. If straight, the ridges are typically "misaligned" with respect to each other, such that the longitudinal directions of the ribs (laterally, orthogonal to tape thickness) extend in two different directions (e.g., 30 degrees, 45 degrees, 90 degrees). Bonding of the ridges at bondpoints (where the ridges contact each other), whether via sintering, gluing, or otherwise, typically connects the two flanges with a multiaxial web, resulting in a multiaxial reinforcement of the resulting filter plate.

[0048] A flange may comprise a polymer, a metal, and/or a ceramic, according to a desired combination of chemical resistance, erosion resistance, ease of manufacturability, plate size, and the like. In an embodiment, at least the flange (and typically the ridges) comprises a ceramic such as SiC, A1203, and/or Ti02. In an exemplary structure, a ridgewidth of one or more ridges does not exceed 4 mm, particularly below about 2mm, the flanges have a thickness that is below 3mm, including below 2 mm, particularly below 1mm. A channel width between adjacent ridges extending from the same flange may be at least 2mm. A plate may have a thickness 330 that is below 1.5 cm, particularly below 8mm. In some implementations, a thin flange (providing for permeation) is connected to a thick flange (providing structural support). For example, a flange having a thickness from 0.1-0.8mm may be connected by ridges to a flange having a thickness from about 3-15mm. [0049] FIG. 4A is a schematic illustration showing an exploded view of a filter plate having a multiaxial web, according to some embodiments. In an embodiment, a first flange comprises (e.g., is formed integrally with) first ridge(s) extending in a first long.direction and second ridge(s) extending in a second long.direction different than the first. A second flange (e.g., a flat porous tape, such as fabricated via tape-casting) does not have ridges. The flanges are sandwiched with the ridges between, such that the ridges on the first flange bond to the flat of the second flange, forming a multiaxial web comprising a plurality of bondpoints connecting the ridges of the first flange to the flat of the second flange (e.g., as lines of bond points). Such a structure may enable the use of a very thin tape-cast flange with a relatively thicker ridged flange (e.g., extruded), which may provide for improved mechanical properties.

[0050] In FIGS. 4 A and B, filter plate 400 comprises two opposing flanges connected by a multiaxial web. FIG. 4A illustrates an "exploded view" of a ridged tape having angled and/or curved ridges 110 on flange 120, wherein at least one ridge 110 includes both a first portion extending in a first long.direction 114 in a first lateral direction 210 (FIG. 2), and a second portion extending in a second long.direction 114' in a second lateral direction 210' (FIG. 2). In FIG. 4A, the top "flat" tape includes a flange 120' without ridges, and the bottom tape includes a flange 120 having ridges 110. One or more pressurized paste containers may include orifices that inject ridges onto a previously cast flat flange (e.g., like miniaturized caulk guns).

[0051] FIG. 4B is a schematic illustration of a cross section of a filter plate having a multiaxial web, according to some embodiments. In this view of plate 400, the web is formed by ridges on one ridged tape 120, with a flat "roof flange 120' subsequently laid on top of the ridges (e.g., after drying or bisque-firing). FIG. 4B illustrates channels 150 formed between the ridges. In this example, bondpoints 510 between the ridges on one flange and the opposing flange itself form the multiaxial web.

[0052] FIGS. 5-8 are schematic illustrations of various filter plates plate having multiaxial webs, per some embodiments. FIGS. 5-8 illustrate "sandwiched" filter plates, with ridges (between the inner surfaces of the flanges) shown as dotted lines. The longitudinal dimension of at least a portion of the ridges extends in at least two different lateral directions 210/210', typically tens of cm to hundreds of cm. Stiffened by the multiaxial web, a thin flange (e.g., below 4mm) may be used in a very large plate (e.g., over lm wide) yet still support a thin membrane (e.g., below 30 microns, including below 10 microns). Exemplary permeate flow for an "outside-in/opening down" configuration with vertical plate orientation is schematically illustrated. A pressure gradient may drive permeate through the flanges. The permeate may trickle downward to open portion 524 for removal.

[0053] Filter plates may be sealed at the edges, typically leaving a portion of the edge unsealed for removal of permeate from the interior. A filter plate has an "outer" edge with respect to permeate flow, although this edge could be an interior circumference of a hole in the plate. The edge of a filter plate may be sealed during sintering and/or after sintering the plate (e.g., with a polymer, such as epoxy, glass, and the like), such that the edge is sealed to prevent flow of the filtered contaminant between the exterior and interior of the plate. The edge may be porous to permeate (e.g., porous flange material). An open portion of the channel in fluidic communication with the interior of the plate (e.g., with the channel network) provides for permeate to flow between the interior and the exterior via the open portion.

[0054] FIGS. 5-8 schematically illustrate outer edges 520 having a sealed portion 522 (sealed to prevent flow of a contaminant between an exterior of the filter plate and the open channels within) and an open portion 524 configured to convey a fluid (e.g., a permeate) between the open channels and the exterior of the filter plate. The edges may be sealed with the same material as the flange or web (e.g., during sintering). In this example, permeate is removed from below. An open portion may be at a side or top of the plate.

[0055] Bond points 510 between opposing/crossing ridges transfer forces between the opposing flanges, and may be bonded before sintering, during sintering, or after sintering (e.g., with adhesive). An areal distribution of bond points is typically designed to be sufficient to reinforce the plate (e.g., to transfer shear forces between flanges without bondpoint failure). Ridges are typically designed such that the distance between ridges is small enough to prevent collapse of the flange under pressure. In these examples, each plate has an edge 500 having a sealed portion 522 (through which contaminants may not pass between the exterior and interior of the plate) and an open portion 524. A sealed portion may be completely sealed or allow permeate flow (as the flange). Typically, open portion 524 is used to deliver fluid to or evacuate fluid from the interior of the plate. Open portion 524 may be at the top, side, or bottom. In these illustrations, open portion 524 is at the bottom, and gravity assists the removal of permeate from the interiors of the plates. A distribution of bondpoints may be chosen according to desired web properties (e.g., webheight, flange thickness, ridge thickness, and material strength).

Bondpoints may be distributed at about 0.5 - 5 bondpoints per cm^A2, including about 2-4 bondpoints per cm^A2. For plates to be cleaned by backwashing (e.g., inside-out pressure to clean outside-in filtration), an increased bondpoint density and strength increases resistance to the tensile forces created in the web by the backpressure.

[0056] In FIG. 5, filter plate 500 has ridges angled downward. In FIG. 6, filter plate 600 has ridges oriented vertically and horizontally. In FIG. 7, filter plate 700 has curved ridges, with opposing flanges/ridges in a "mirror" orientation to generate the desired number and distribution of bondpoints 510. In FIG. 8, plate 800 comprises a first ridged flange having curved and point-ridges and a flat top flange (without ridges). A ridged tape (e.g., per FIG. 16) may receive a flat "roof flange 120' (FIG. 4B) such that only one tape's ridges create the web. By orienting the channels toward the outlet portion of the edge, fluid within the channels may exit the interior of the plate. Ridges deposited such that their longitudinal directions span a range of lateral dimensions (optionally reinforced with pillars 810, as shown) may be oriented such that channels between the ribs flow to the open portion of the edge.

[0057] FIG. 9 is a schematic illustration of certain aspects of a filter plate having a multixial web and coated with a membrane, per an embodiment. The lower portion of FIG. 9 illustrates plate 900 in cross section, showing orthogonally oriented ridges 110/110' connected at bondpoints 510 to yield the multiaxial web. In addition to use as a filter itself, a multiaxially reinforced filter plate may provide a membrane with high strength and stiffness with minimal flange thickness (increasing permeability while supporting the membrane) yet still be manufactured in large sizes (over 1 square meter/plate, including over 5 square meters/plate, including over 10 square meters/plate).

[0058] A filter plate often has at least one, including at least two, or even three or more membrane layers. A filter plate may include at least one membrane, typically disposed on the surface facing the contaminated fluid. One or more membranes may be included in a membrane. A membrane may be below 40 microns thick, including below 20 microns thick.ln an "outside-in" configuration, the contaminated fluid 950 to be filtered is exterior to filter plate 900, and typically a pressure drop drives permeate 940 through the flanges of the plate into the interior of the plate, where it flows to the manifold for removal. Permeate 940 may flow down to an open portion of the edge of the plate into a manifold 1020 (in this case, at the bottom of the plate, FIG. 10). A retentate 930 (having increased contaminant concentration as permeate 940 is removed) continues past the plate. Although ridges 110/110' provide for multiaxial longitudinal reinforcement, they typically include continuously interconnected open channels, enabling free permeate flow throughout the interior of the plate despite the multiaxial strengthening.

[0059] Membrane median pore diameter is typically less than 30%, commonly less than 10%, of that of the substrate or preceding membrane layer upon which the membrane is deposited (whether the flange itself or an underlying membrane). For a substrate having a median pore diameter from about 15-50 microns, an exemplary membrane(s) (e.g., for water filtration) may have a median pore diameter ranging from lOnm to 3 microns, typically over 2-3 separate membranes (e.g., an inner membrane with mpd of 1-4 microns, a middle membrane that is thinner than the inner membrane and having an mpd of 100-600nm, and an outermost membrane that is thinner than the inner membrane and having an mpd of 10-50nm. Each successively deposited membrane (inner to outer) may have a thickness that is from about 10% -75% of the membrane upon which it is deposited. Each successive layer typically has an mpd that is 1-20% of the mpd of the surface onto which it is deposited.

[0060] In this example, filter plate 900 has a first (in this case, inner) membrane 910 disposed on the outer surfaces of the flanges and a second (in this case, outer) membrane 920 disposed on the outside of the first membrane 910. An outer membrane typically has a smaller MPD than the membrane or layer upon which it is deposited. In an embodiment, a filter plate has an inner membrane 910 having a median pore size between 80nm and 3 microns (e.g., 200 nm to 2 microns), and an outer membrane 920 having a median pore size between 10 nm and 120 nm (e.g., 20 nm to 80nm). An inner membrane 910 may have a median pore diameter between 1 and 10 microns, and an outer diameter may have a median pore diameter between lOOnm and 1 micron. An outer membrane may be less than 50%, including less than 20%, of the thickness of the inner membrane. An outer membrane may be between 500nm and 10 microns thick, and an inner membrane may be between 5 microns and 50 microns thick. Typically, a stack of membranes is below 50 microns thick, with the innermost membrane having a smaller pore size than the underlying flange. Pore size and membrane thickness typically decreases going from innermost to outermost membrane. The outermost membrane might be below 3 microns, including below lmicron thickness and have a median pore size below lOOnm, including below 50nm. [0061] FIG. 10 is a schematic illustration of a filtration system, according to some embodiments. A filtration system 1000 may comprise a container 1010 having a fluid inlet 1012 configured to receive a contaminated fluid 950 (FIG. 9) and a retentate outlet 1014 configured to convey retentate. The system may include one or more (typically at least 10, including over 100) filter plates disposed within the container such that fluid flows past the plates. A manifold 1020 may be fluidically coupled to one or more plates to gather and remove a permeate 940 (FIG. 9). In this example, plates are oriented vertically, with their open edge portions and corresponding manifolds 1020 disposed at the bottom of each plat. Permeate flows through the (vertically oriented) flanges of the plates, into the interiors, down the channels, to the manifolds, where it is extracted. Open edges and their manifolds may be located at the sides of the plates, or even at the tops of the plates.

[0062] A pump (e.g., a vacuum pump or a pressurizing pump) may be used to drive the pressure gradient across the flanges, driving permeate through the flanges. In this example, a vacuum pump 1030 evacuates the manifolds. A pump may pressurize the contaminated fluid exterior to the plates. For top (and to a lesser extent, side) manifold-systems, the pressure drop is typically larger than the gravitational effect on the permeate, such that the permeate is "pumped out" of the plate. For bottom- oriented manifolds, gravity may be sufficient to remove permeate, which may reduce the required pressure drop (reducing pumping energy required). A frame 1040 may hold the plates and/or manifolds (e.g., with the plates aligned with fluid flow direction).

[0063] Multiaxially reinforced plates may be fabricated in large sizes. A smallest lateral dimension may be greater than 50cm, including greater than lm, including above 2m. Uniaxially reinforced extruded filters typically cannot be made in these sizes. The constraints required to extrude "closed" channels in prior planar ceramic substrates limits extrusion width to 30cm or so. In contrast, ridged tapes may be extruded at much larger widths, resulting in plates having much larger sizes.

[0064] FIG. 11 is a schematic illustration of an extrusion process to fabricate a ridged tape, according to some embodiments. An extruder may extrude a paste into a ridged tape onto a smooth surface (e.g., with the ridges facing up), enabling fabrication of a very thin, very wide flange without sagging. In fabrication system 1100, an extruder 1110 is configured to extrude a ridged tape. Tapes are typically fabricated "flange-down" onto a smooth surface 1120, which may be lubricated (e.g., with an air bearing). In some cases, smooth surface 1120 comprises a thin film (e.g., polyethylene,

polypropylene) which may move with the extrusion. Extrusion typically entails relatively high pressure to extrude a thick paste through small orifices. As a result (e.g., as in diesel particulate filters, catalytic converters), very thin flanges, tall ridges, and/or thin ridges may be integrally formed. By extruding a tape, rather than an entire filter volume (as in a DPF), lower paste viscosities may be used. As a result, mixing energy, extrusion energy, and erosion may be reduced. With decreased die deformation of lower viscosity and pressure, very wide tapes may be fabricated, enabling large filter plates.

[0065] A ceramic tape may be fabricated from a mixture of powders (e.g., SiC, A1203, Ti02, boehmite, and the like), water binder (e.g., PVA), plasticizer, lubricant, and the like. A paste is typically kneaded in a mixing machine, de-aired, then extruded. A fugitive phase (e.g., carbon) may be added, which is subsequently removed (e.g., during burnout) to enhance porosity. It may be advantageous to use a bimodal grain size distribution for the ceramic powder (e.g., 80% coarse/20% fine) with the fine portion having a median grain size that is -10% of that of the coarse portion.

[0066] FIG. 12 is a schematic illustration of an exemplary extrusion die, according to some embodiments. FIG. 12 illustrates the "outlet" end of a die 1200 configured to extrude a ridged tape 100. Extrusion may be advantageous for the fabrication of ridged tapes having relatively larger aspect ratios than stamped or cast tapes. An extruded ridge may have a tall ridge.height 112 yet still have a relatively thin ridge.width 111 (FIG. 1A). As a result, webheight may be maximized (increasing plate strength) while maximizing the open interior channel surface area for permeation. (FIG. 13) An extruded ridge may have a tall ridge.height 112 yet still have a relatively thin flange thickness (122, 122'). As a result, the plate may be stiff er/stronger, yet still have a high permeability. Manufacturability and tolerance may be improved even as filtration performance is improved.

[0067] A flat flange may be tapecast or extruded, and ridges optionally deposited in the flange. In an embodiment, the web is extruded separately (e.g., like rotelle pasta) and placed on a flat flange. A ridge may be printed, injected, or otherwise deposited onto a flange. Separate ridge extrusion may enable the laying of curved and/or angled ridges on a flat tape.

[0068] In an exemplary process for fabricating a multiaxially reinforced filter plate, first and second ridged flanges are extruded. The first ridged flange comprises a first porous ceramic flange and one or more first ridges extending in a first long.direction aligned in a first lateral direction orthogonal to a thickness of the flange. The second ridged flange comprises a second porous ceramic flange and one or more second ridges extending in a second long.direction orthogonal to the thickness of the second flange. The flanges are stacked, ridge-to-ridge, such that the first ridge(s) of the first flange contact the second ridge(s) of the second flange, with the ridges "misaligned" such that (with respect to the stacked flanges) the first long.direction is different than the second long.direction. Bondpoints between the facing ridges are bonded (e.g., during sintering, after sintering) to form a multiaxial web connecting the inside surfaces of the flanges. Bondpoints may be sintered. Bondpoints may be glued at high temperature (e.g., with glass) and/or at room temperature (e.g., with PU, epoxy, etc.).

[0069] A method may comprise forming a first ridged tape and bonding it to a flat second tape to form a multiaxial web between the tapes, which form flanges. A first ridged tape may comprise a first porous ceramic flange and one or more first ridges extending laterally (with respect to the thickness of the flange) in at least a first long.direction and a second long.direction. A second, flat flange (e.g., a tape-cast tape) need not have ridges, as the multidirectional ridges are on the first flange. The flanges may be stacked (ridged to flat) such that the ridges of the first flange contact the second flange. The resulting contact points may be bonded to form bondpoints (e.g., lines, curves, and the like). The resulting multidirectional ridges form a multiaxial web connecting the first and second flanges. The ridges may be deposited (e.g., injected, printed) onto the flat tape. In some cases, a mask (having the desired ridge height) is overlaid onto a tape, the ridges are printed through the mask (e.g., as in a silk- screen printing) and the mask is removed, leaving the ridges. [0070] One or more membranes may be deposited on the filter plate (typically on the outside surface). A membrane may be deposited before sintering and co-fired with the filter plate. A membrane may be deposited after sintering. The membrane may be the same or different material. Bondpoints (between ridges, or ridge-surface) may be created via sintering, gluing, or other reactions. In some cases a plate is fabricated during sintering, and bondpoints form in-situ. In some cases, the flanges (ridged or not) are fired, and the bondpoints are fabricated afterwards (e.g., via gluing with a polymer, such as epoxy or polyurethane). A glass may be used to form bondpoints (e.g., having a relatively lower softening point than the sintering temperature of the flanges/ridges).

[0071] FIG. 13 is a schematic illustration of an exemplary synthesis process, according to some embodiments. In system 1300, a ridged tape 100 is cut by a knife 1301 to form opposing "faceup" and "facedown" portions to fabricate a filter plate (e.g., as in FIG. 6). A first tape may be inverted with respect to and placed upon a second tape to orient their ridges at different angles. Tapes may be manipulated using a stiff (e.g., steel) surface with an air manifold and distributed holes. The manifold may be evacuated, such that the holes pull the flange onto the surface, enabling handing of the surface/tape. The holes may be pressurized (like an air-hockey table) to release and/or transport the tape.

[0072] FIG. 14 is a schematic illustration of an exemplary synthesis process, according to some embodiments. A knife 1401 may comprise a circumferential blade shaped to cut out entire tapes like a cookie-cutter. The apparatus of claim 14 may be used to fabricate a filter plate as shown in FIG. 5, with similar "flip, twist, and stack" procedure. Tapes may be rolled into a filter plate.

[0073] FIG. 15 is a schematic illustration of an exemplary synthesis process, according to some embodiments. A paste may be squirted and/or printed through small orifices onto a flat tape 120' (e.g., made by tape casting) to form ridges and/or points that become the web. The "guns" squirting the features may oscillate sideways as the tape passes underneath, creating ridges that have their longitudinal directions span a range of lateral directions on the tape. The "guns" may inject features that become pillars between flanges.

[0074] In system 1500, a flat tape is fabricated (e.g., by a tape caster, not shown) and ridges are deposited on the tape by a deposition tool 1520 to create a ridged tape 1510. Deposition tool 1520 may include a pressurized manifold having ridge paste within, and orifices through which the paste is injected onto the flange. In some cases, tool 1520 moves (e.g., laterally) as the flat tape passes beneath, yielding curved and/or angled ridges (as shown in FIG. 15). In an embodiment, a ridged tape is folded on top of itself at a fold 1530 to form a filter plate (e.g., as in FIG. 7). Tapes may be rolled (e.g., to form cylindrical filter plates).

[0075] FIG. 16 is a schematic illustration of an exemplary synthesis process, according to some embodiments. Paste guns may deposit "dots" or "pillars" to reinforce a tape. In this example, ridged tape 1610 is fabricated by depositing ridges 110 and pillars 810 onto a flat tape 120'. A flat tape may be place atop a ridged tape to form a filter plate (e.g., as in FIG. 8). Pillars may be located where "drumhead strain" is at a maximum, providing localized support of the flanges. [0076] Various aspects have been described using ceramic materials, such as SiC, A1203, and the like. Metallic and intermetallic materials may be used. Polymers may be used (e.g., PEEK, PTFE). Various features described herein may be implemented independently and/or in combination with each other. An explicit combination of features does not preclude the omission of any of these features from other embodiments and features may be combined, notwithstanding that this combination might not be explicitly disclosed as such. The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.

Claims

1. A multiaxially reinforced filter plate (300, 400, 500, 600, 700, 800, 900) comprising:

a first porous ceramic flange (120) having a thickness (122) below 5mm, at least 30% porosity, a median pore diameter below 50 microns, an inside surface (130) and an outside surface (140);

a second porous ceramic flange (120') having a thickness (122') below 5mm, at least 30%

porosity, a median pore diameter below 50 microns, an inside surface (130') and an outside surface (140');

a multiaxial web (310) comprising one or more ridges (110, 110') and connecting the inside surfaces (130, 130') of the flanges (120, 120'), the web (310) having:

at least a portion of a ridge (110) extending in a first long. direction (114) aligned in a first lateral direction (210) orthogonal to a platethickness (330) of the plate; at least a portion of a ridge (110') extending in a second long.direction (114') aligned in a second lateral direction (210') different than the first lateral direction (210); and

a webheight (312) that is at least twice as large as the thickness (122, 122') of at least one particularly both, flanges (120, 120'); and

a network of one or more open channels (150) between the flanges and providing for fluid communication between the inside surfaces of the flanges and an edge (520) of the plate, the channels having a cross-section-area greater than 4mm^A2, particularly greater than 9mm^A2.

2. The filter plate of claim 1, wherein:

at least one flange (120, 120') has a thickness (122, 122') below 3mm; and

a channel width (152) between adjacent ridges (110, 110') extending from the same flange (120, 120') is at least 2mm.

3. The filter plate of either of claims 1 and 2, wherein:

both flanges have a thickness below 2 mm;

a ridge. width (111) of the ridges (110, 110') does not exceed 3 mm; and

the webheight (312) is at least 4mm.

4. The filter of any of claims 1-3, wherein:

the first flange (120) is fabricated from a first ridged tape (100) comprising the first ridge (110) extending in the first lateral direction (210);

the second flange (120') is fabricated from a second ridged tape (100') comprising the second ridge (110') extending in the second lateral direction (220); and

the multiaxial web (310) comprises a plurality of bondpoints (510) connecting the first and second ridges (110, 110'), particularly with at least 2 bondpoints per square cm of filtration surface area.

5. The filter of any of claims 1-3, wherein:

the first flange (120) is fabricated from a ridged tape (100) comprising the ridges (110, 110') extending in the first long.direction (114) and the second long.direction (114');

the second flange (120') does not have ridges; and

the multiaxial web (310) comprises a plurality of bondpoints (510) connecting the ridges (110, 110') of the first flange (120) to the second flange (120'), particularly linear bondpoints (510).

6. The filter plate of any of claims 1-5, wherein:

the porous ceramic flanges (120, 120') comprise silicon carbide or aluminum oxide;

a ridgewidth (111) of the one or more ridges (110, 110') does not exceed 2 mm;

the flanges (120, 120') have a thickness (122, 122') that is below 2 mm, particularly below 1mm; and

the platethickness (330) is below 1 cm, particularly below 7 mm.

7. The filter plate of any of claims 1-6, further comprising at least one membrane (910, 920) disposed on the outside surfaces (140) of the flanges, the membrane having a median pore diameter between 10 nm and 3 microns and less than 25% of the median pore diameter of at least one flange (120, 120').

8. The filter plate of claim 7, wherein the membrane comprises:

a first, particularly inner, membrane (910) having a median pore diameter between 80nm and 3 microns, and

a second, particularly outer, membrane (920) having a median pore diameter between lOnm and 120nm, the second membrane having a median pore diameter that does not exceed 20% of the median pore diameter of the first membrane.

9. The filter plate of any of claims 1-8, wherein a ratio of a webheight (312) of the web (310) to the thickness (122, 122') of at least one flange is at least 3, particularly greater than 4.

10. The filter plate of any of claims 1-9, further comprising an outer edge (520) having:

a sealed portion (522) sealed to prevent flow of a contaminant between an exterior of the filter plate and the open channels (150); and

an open portion (524) in communication with the network of one or more open channels and configured to convey a permeate (940) between the open channels (150) and an exterior of the filter plate.

11. A filtration system (1000) comprising:

a container (1010) having a fluid inlet (1012) and a retentate outlet (1014)

at least one filter plate according to claim 9 disposed within the container,

a manifold (1020) fluidically coupled to the open portion (524) of the outer edge (520)

configured to gather a permeate (940) from the open channels; and

a pump (1030) configured to evacuate the permeate (940) from the manifold (1020) and/or pressurize the fluid (950) exterior to the filter plate to drive permeate into the open channels,

particularly wherein the filter plate is oriented vertically, and the manifold and open portion of the filter plate are disposed at a bottom of the filter plate.

12. A method for fabricating a multiaxially reinforced filter plate, the method comprising:

extruding a first ridged tape comprising:

a first porous ceramic flange (120); and

a first ridge (110) extending in a first long.direction (114) aligned in a first lateral direction (210) orthogonal to a thickness (122) of the first flange (120);

extruding a second ridged tape comprising:

a second porous ceramic flange (120'); and

a second ridge (110') extending in a second long.direction (114') aligned in a second lateral direction (210') orthogonal to a thickness (122') of the second flange (120');

stacking the first and second ridged tapes such that:

the first ridges (110) contact the second ridges (110') at a plurality of bondpoints (510); and the second lateral direction (210') is different than the first lateral direction (210); and bonding the bondpoints (510) to form a multiaxial web (310) connecting inside surfaces (130, 130') of the flanges (120, 120').

13. A method for fabricating a multiaxially reinforced filter plate, the method comprising:

forming a first ridged tape comprising:

a first porous ceramic flange (120); and

one or more first ridges (110, 110') extending, laterally with respect to a thickness of the flange(120), in at least a first long.direction (114) and a second long.direction (114') different than the first long.direction (114);

forming a flat tape to form a second porous ceramic flange (120') not having ridges;

stacking the first and second tapes such that the ridges of the first flange (120) contact a surface of the second flange (120'); and

bonding the ridges of the first flange (120) to the second flange (120') to form a multiaxial web (310) connecting the flanges (120, 120') via the one or more ridges (110, 110').

14. The method of claim 13, wherein forming the first ridged tape comprises:

forming the first flange as a flat tape; and

depositing the one or more first ridges (110, 110') onto the flat tape.

15. The method of either of claims 13 and 14, further comprising depositing one or more membranes (910, 920) on a surface of the plate, particularly an exterior surface.

16. The method of any of claims 13-15, wherein bonding comprises sintering the ridges to the contacting ridges and/or plate, respectively.

17. The method of any of claims 13-15, wherein bonding comprises bonding the ridges to the contacting ridges and/or plate, respectively, using a polymer, particularly epoxy or polyurethane.

18. The method of any of claims 13-15, wherein bonding comprises bonding the ridges to the contacting ridges and/or plate, respectively, using a glass.