Abstract: A process comprising a duplex type impregnating apparatus providing the steps of: (i) providing an elongated porous web, said elongated porous web comprising two outermost surfaces; (ii) transporting said elongated porous web downwards between two impregnating heads comprising two slots each with substantially vertical upper and lower slot faces substantially parallel to said elongated porous web providing simultaneously to both surfaces of said elongated porous web metered substantially identical quantities of a dope, comprising at least one membrane polymer and at least one solvent therefor; (iii) thereby impregnating said elongated porous web completely with said dope and providing substantially equally thick dope layers on each surface of said outermost surfaces of said elongated porous web with a thickness independent of the gap between one of said lower slot faces and the surface of said elongated porous web nearest thereto; (iv) subjecting said dope associated with said elongated porous web to symmetri

Abstract: Process comprising the steps of: (i) providing an elongated porous web, said elongated porous web comprising two outermost surfaces; (ii) transporting said elongated porous web downwards between two impregnating heads comprising two slots each with substantially vertical upper and lower slot faces substantially parallel to said elongated porous web providing simultaneously to both surfaces of said elongated porous web metered substantially identical quantities of a dope, comprising at least one membrane polymer and at least one solvent therefor; (iii) thereby impregnating said elongated porous web completely with said dope and providing substantially equally thick dope layers on each surface of said outermost surfaces of said elongated porous web with a thickness independent of the gap between one of said lower slot faces and the surface of said elongated porous web nearest thereto; (iv) subjecting said dope associated with said elongated porous web immediately after dope-impregnation to symmetric phase inver

Abstract: A membrane bag comprising a volume for permeate collection, wherein the volume is completely enclosed in seamless membrane substance; a filtration unit comprising at least one above-described seamless membrane bag; the use of at least one above-described seamless membrane bag in a membrane bioreactor; the use of at least one above-described seamless membrane bag in water filtration or waste water purification; and the use of at least one above-described seamless membrane bag for the filtration or separation of a mixture of fluids, vapors and particles.

Abstract: Disclosed are seamless membrane bags, for example, a membrane bag comprising a spacer fabric and a volume for permeate collection, the spacer fabric comprising a first part and a second part that are spaced apart and tied together at a predefined distance by monofilament thread and the first and second parts are at least partially embedded with membrane substance and the volume for permeate collection is interposed between the first and second parts. The membrane substance embeds portions of the monofilament thread and fills the spacer fabric along the border of the membrane bag. The membrane substance completely enclosing the volume is seamless. Also disclosed are processes for producing such bags, a filtration unit comprising such a membrane bag, and their uses in the separation of fluids, vapors and particles.

Abstract: Process comprising the steps of: (i) providing an elongated porous web, said elongated porous web comprising two outermost surfaces; (ii) transporting said elongated porous web downwards between two impregnating heads comprising two slots each with substantially vertical upper and lower slot faces substantially parallel to said elongated porous web providing simultaneously to both surfaces of said elongated porous web metered substantially identical quantities of a dope, comprising at least one membrane polymer and at least one solvent therefor; (iii) thereby impregnating said elongated porous web completely with said dope and providing substantially equally thick dope layers on each surface of said outermost surfaces of said elongated porous web with a thickness independent of the gap between one of said lower slot faces and the surface of said elongated porous web nearest thereto; (iv) subjecting said dope associated with said elongated porous web immediately after dope-impregnation to symmetric phase inver

Abstract: An apparatus for producing an ion-permeable web-reinforced separator comprising a duplex type impregnating apparatus comprising two slots each with substantially vertical upper and lower slot faces for providing premetered substantially identical quantities of a dope simultaneously to either side of an elongated porous web, a transport means providing for substantially vertical downwards transport of said elongated porous web through said duplex impregnating apparatus and subsequent phase inversion, coagulation and washing stations, said phase inversion station providing for phase inversion of said dope and said coagulation station providing for coagulation and washing of solvent from the resulting phase-inverted dope, wherein there is an air gap between said duplex impregnating apparatus and said phase inversion station and wherein the distance between the lower faces of each impregnating apparatus is greater than the distances between the upper faces of each impregnating apparatus; a process comprising the

Abstract: Disclosed are seamless membrane bags for example, a membrane bag comprising a spacer fabric and a volume for permeate collection, the spacer fabric comprising a first part and a second part that are spaced apart and tied together at a predefined distance by monofilament thread and the first and second parts are at least partially embedded with membrane substance and the volume for permeate collection is interposed between the first and second parts. The membrane substance embeds portions of the monofilament thread and fills the spacer fabric along the border of the membrane bag. The membrane substance completely enclosing the volume is seamless. Also disclosed are processes for producing such bags, a filtration unit comprising such a membrane bag and their uses in the separation of fluids, vapours and particles.

Abstract: A membrane bag comprising a volume for permeate collection, wherein the volume is completely enclosed in seamless membrane substance; a filtration unit comprising at least one above-described seamless membrane bag; the use of at least one above-described seamless membrane bag in a membrane bioreactor; the use of at least one above-described seamless membrane bag in water filtration or waste water purification; and the use of at least one above-described seamless membrane bag for the filtration or separation of a mixture of fluids, vapours and particles.