A membrane distillation module comprising a membrane distillation cartridge and a membrane distillation housing, wherein: the cartridge comprises a anchoring part in which porous membranes are anchored by resin; the housing comprises a housing body and a housing lid; the membrane distillation module comprises a support part where the outer surface of the anchoring part is supported by the inner surface of the housing with a seal member interposed therebetween; and a value C in the cross section of the support part is at least 30 C. as represented by the formula, where d.sub.F is the equivalent circular diameter (mm) of the outer circumference of the anchoring part, k.sub.F is the linear expansion coefficient (1/ C.) of the resin, d.sub.E is the equivalent diameter (mm) of the inner circumference of the housing, and k.sub.E is the linear expansion coefficient (1/ C.) of a portion where the housing contacts the seal member.

Provided is a porous polytetrafluoroethylene (PTFE) membrane that satisfies the following expressions: 0.2F4.0; 0.2R1.0; and R0.1F+0.5, for the Frazier number F [cm.sup.3/sec/cm.sup.2] and the water entry pressure R [MPa]. This porous PTFE membrane may be a single-layer membrane. This porous PTFE membrane has the properties suitable for use as a waterproof air-permeable membrane, and achieves a good balance between high water resistance and high air permeability.

A filtration filter comprises a metallic mesh having a circumferential shape and radially inner and outer portions. The metallic mesh is adapted to filter out a filtration target object contained in a fluid passing through the membrane. First and second frame members hold the outer portion there between so as to create first and second bent sections separated by a transition section extending between the first and second bent sections. The transition section includes at least one streaked projection.

A potting material for membrane modules which is formed of an epoxy resin composition, in which the mass change ratio of a cured product of the epoxy resin composition after being immersed in diethylene glycol methyl ethyl ether at 40 C. for one week is 10% or less, and the mass change ratio thereof after being immersed in tetrahydrofurfuryl acrylate at 40 C. for one week is 5% or less, and a hollow fiber membrane module which uses the potting material for membrane modules.

A hollow fiber membrane sheet-like object in which a plurality of hollow fiber membranes is aligned in parallel with each other and fixed to each other while both end faces of each of the hollow fiber membranes in a longitudinal direction are open, wherein at least one belt-like binding portion made of an elastic body having an elongation percentage (E) stipulated by JIS K6251 of 100% or more and extending in a direction perpendicular to the longitudinal direction is formed at each of both end portions of the hollow fiber membrane sheet-like object, and the plurality of hollow fiber membranes is fixed to each other.

An enclosure assembly configured to receive a plurality of fiber membranes configured to filter fluid may include an elongated tubular member including an elongated wall extending between first and second ends, and a removable hatch coupled to opposing side edges of the elongated wall, thereby forming a hollow enclosure having an interior. The interior of the elongated tubular member may be configured to receive a plurality of fiber membranes configured to filter fluid.

A filter element for cleaning liquids, having a stack of at least two filter membrane pockets, which are substantially flat and include a flexible, liquid-permeable filter material for retaining waste particles and/or microbes, wherein each filter membrane pocket has a substantially polygonal shape with at least three corners and a corresponding number of edges, wherein the filter membrane pockets are stacked with a defined distance and aligned with each other, wherein aligned corners of the filter membrane pockets are embedded in a casting covering only part of the adjacent edges such that the casting for each corner is spaced from the castings of the neighboring corners.

Disclosed is a filtering apparatus which comprises a plurality of hollow fiber membrane modules installed in a frame structure with high packing density so that the recovery rate of the filtering apparatus can be increased, and performs the aeration cleaning of the hollow fiber membrane modules in efficient way. The filtering apparatus of the invention comprises a frame structure including first and second internal spaces, a first hollow fiber membrane module installed in the first internal space, and a second hollow fiber membrane module installed in the second internal space.

A method of manufacturing a tube sheet by forming a plurality of separate thin tube sheet segments; forming multiple holes in each sheet in a predetermined pattern, each hole for accommodating a tube sheet filter tube; aligning all of the plurality of tube sheet segments so that the hole pattern of each sheet aligns with the hole pattern in all other sheets of the plurality of tube sheet segments; and securing all of the tube sheet segments together to form a unitary tube sheet. A tube sheet construction that includes a plurality of separate thin tube sheet segments, multiple holes being provided in each sheet in a predetermined pattern, each hole for accommodating a tube sheet filter tube, all of the tube sheet segments being aligning so that the hole pattern of each sheet aligns, and fasteners for securing all of the tube sheet segments together. A media layer is provided between adjacent sheet segments.

A method for potting hollow fiber membranes comprises the steps of forming a bundle of membranes with a layer of adhesive; covering one end of the bundle with a permeate pan, the ends of the membranes protruding upwards into the permeate pan; and flowing a liquid potting material into the permeate pan. The bundle may be tilted to more quickly distribute the liquid potting material. An apparatus for filtering liquid with hollow fiber membranes comprises a bundle of membranes, a layer of adhesive spaced from the end of the bundle, a permeate pan covering the end of the bundle, and a header formed with the membranes, the adhesive and the pan.