EP-4741045-A1 - A METHOD OF PRODUCING A SPIRALLY WOUND FILTRATION MODULE AND A SPIRALLY WOUND FILTRATION MODULE

EP4741045A1EP 4741045 A1EP4741045 A1EP 4741045A1EP-4741045-A1

Abstract

The present invention relates to a method of producing a spirally wound filtration module for filtrating a fluid feed into a retentate portion and a permeate portion. The method comprises the step of stacking membrane filtration assemblies and permeate transfer layers on top of each other where each membrane filtration assembly being located between two permeate transfer layers starting with a first permeate transfer layer and ending with a final permeate transfer layer. The leading edges of the membrane filtration assemblies are facing the permeate tube and being sequentially offset. The final permeate transfer layer covers all the leading edges of the membrane filtration assemblies. The method comprises the step of rolling the membrane filtration assemblies and the permeate transfer layers around the permeate tube forming the filtration module.

Inventors

LARSEN, HENRIK

Assignees

Alfa Laval Corporate AB

Dates

Publication Date: 20260513
Application Date: 20241106

Claims (15)

A method of producing a spirally wound filtration module for filtrating a fluid feed into a retentate portion and a permeate portion, the method comprising the steps of: providing a permeate tube extending in a first direction between a first end and a second end, the permeate tube defining a plurality of perforations, providing a first set of membrane filtration assemblies, each membrane filtration assembly defining a leading edge each and comprising: a first membrane layer, a feed transfer layer and a second membrane layer stacked on top of each other, providing a second set of permeate transfer layers, stacking the membrane filtration assemblies and the permeate transfer layers on top of each other, each membrane filtration assembly being located between two permeate transfer layers starting with a first permeate transfer layer and ending with a final permeate transfer layer, the first permeate transfer layer being in contact with the permeate tube between the first end and the second end and extends away from the permeate tube in a second direction being perpendicular to the first direction, the leading edges of the membrane filtration assemblies facing the permeate tube and being sequentially offset along the second direction, the final permeate transfer layer covering all the leading edges of the membrane filtration assemblies, and rolling the membrane filtration assemblies and the permeate transfer layers around the permeate tube forming the filtration module.
The method according to claim 1, wherein the first membrane layer and the second membrane layer constitute a single sheet folded about the feed transfer layer at the leading edge.
The method according to any of the preceding claims, wherein the total sequential offset between the leading edges of the membrane filtration assemblies along the second direction substantially correspond to the circumference of the permeate tube.
The method according to any of the preceding claims, wherein the first set is between 4-50 membrane filtration assemblies, preferably between 6-20 membrane filtration assemblies.
The method according to any of the preceding claims, wherein the number of permeate transfer layers are one more than the number of membrane filtration assemblies.
The method according to any of the preceding claims, wherein the filtration modules is wrapped by a grid material.
The method according to any of the preceding claims, wherein the permeate transfer layers and the feed transfer layers are in the form of nets or meshes.
The method according to any of the preceding claims, wherein the permeate transfer layers being glued to the adjacent membrane layers.
The method according to claim 8, wherein the permeate transfer layers being glued to the adjacent membrane layers along all edges except the leading edge.
The method according to any of the preceding claims, wherein a weight is placed on the final permeate transfer layer during rolling.
The method according to any of the preceding claims, wherein the final permeate transfer layer extend a shorter distance in the second direction than the other permeate transfer layers, such as substantially from the first leading edge to the final leading edge.
The method according to any of the preceding claims, wherein the first permeate transfer layer define a cut out area substantially corresponding to the area of the final permeate transfer layer in the filtration module.
A spirally wound filtration module for filtrating a fluid feed into a retentate portion and a permeate portion, the spirally wound filtration module comprising: a permeate tube extending substantially between a first end and a second end in a first direction, the permeate tube defining a plurality of perforations, a first set of membrane filtration assemblies, each membrane filtration assembly defining a leading edge each and comprising: a first membrane layer, a feed transfer layer and a second membrane layer stacked on top of each other, and a second set of permeate transfer layers, the membrane filtration assemblies and the permeate transfer layers being spirally wound around the permeate tube in a spiral direction being perpendicular to the first direction, each membrane filtration assembly being located between two permeate transfer layers starting with a first permeate transfer layer and ending with a final permeate transfer layer, the first permeate transfer layer being in contact with the permeate tube between the first end and the second end, the leading edges of the membrane filtration assemblies facing the permeate tube and being sequentially offset along the spiral direction, the final permeate transfer layer covering all the leading edges of the membrane filtration assemblies.
The spirally wound filtration module according to claim 13, further comprising any of the features according to any of the claims 2-12.
Use of a spirally wound filtration module according to claim 13 or 14 in a filtration system.

Description

The present invention relates to a method of producing a spirally wound filtration module and a spirally wound filtration module. Introduction Sanitary filtration plants using spiral wound filtration modules can be used for reverse osmosis, nanofiltration, ultrafiltration and microfiltration to efficiently recover, purify, fractionate or concentrate products in industries such as food, beverage, dairy, biotech/biobased chemicals and pharma. Sanitary filtration plants of the above type are known to use filtration modules comprising membrane filtration assemblies spirally wound on permeate tubes. In a typical filtration plant the filtration modules will be disposed within the non-permeable filter housing of the sanitary filtration plant. Pumps will be used to pump a fluid feed through the filter module which is disposed in the housing. The fluid feed enters at one end of the filter housing and travels through the filtration module via wound feed transfer layers positioned parallel to and between wound membrane layers of the membrane filtration assemblies. Separation occurs at the membrane-fluid interface, in with part of the fluid, called the permeate, passes through the membrane layer while the rest of the fluid feed, called the retentate, remains in feed transfer layers on the opposite side of the membrane and becomes a more concentrated feed. The permeate stream travels in permeate transfer layers sandwiched between the membrane filtration assemblies in an inwardly spiralling radial direction until it passes through the perforations of the permeate tube for recovery from one or both ends of the permeate tube. The following documents can be considered representative prior art in the present context: US 2013/0161258 A1 relates to a brine seal for a spiral wound membrane element. The brine seal has an elongate body with a flexible wing. The brine seal is wrapped around the spiral membrane element with a space between each turn of the brine seal. JP 2011/092905A relates to a membrane with protrusions. US 8668828 relates to spiral wound membrane cartridge having a thin tubular shell having a textured exterior surface to allow controlled bypass flow of liquid feed between a pressure vessel interior and a textured exterior surface of the shell. US 5985146 relates to a fluid separation device having a rigid, nonporous shell and a spiral wound membrane filtration element positioned inside the rigid, nonporous shell. A threaded groove running around the circumference and down the length of the exterior surface of the shell. US 4064052 relates to a spirally wound membrane having a lip seal between the module and the containment tube. US 2009/0200237 A1 relates to a filter media having a flow control strip circumferentially surrounding the media at one end. The strip preferably is an open mesh material that cooperates with an overlapping portion of an open mesh net that surrounds the filter media. The strip creates a compressible area that restricts bypass flow while allowing for easy installation and removal of the membrane module. US 4839037 relates to a spirally wound filter cartridge including a centrally disposed tube and a sheet of filtration material spirally wound around the tube. US 5128037 relates to a spiral wound filtration cartridge having an end plate for controlling fluid flow within the space between the outer cylinder and the housing. US 4902417 relates to a spiral wound membrane cartridge having a feed layer having a plurality of parallel ribs. US 4548714 relates to a membrane cartridge for insertion into a pressure resistant container. The cartridge has a porous grid material having an extension which is of sufficient length to encompass the circumference of the cartridge when the cartridge is positioned inside the container. US 5073263 relates to an ultrafiltration module comprising a permeate collector tube, one or more membrane leaves wound around the tube, an outer wrap screen circumscribing the wound leaves and a bypass screen also of open mesh configuration is wrapped around the outer wrap. US 3063888 relates to a filter tube having a strip of foraminous material. US 5460720 relates to a fluid separation device, utilizing tubular or flat sheet membrane materials, bounded on the membrane side of the sheet by a sheet of a porous feed spacer material. WO 2022/187472 A1 relates to a by-pass control sleeve has circumferential protrusions along its outer surface. The rolling technique is a crucial process in the production of spirally wound filtration modules. Correct rolling ensures the efficient and compact arrangement of membrane filtration assemblies and permeate transfer layers around a central permeate tube, optimizing the filtration performance and structural integrity of the module. For ensuring the highest possible quality, the stacking of the layers and the rolling of the spirally wound filtration modules typically involves manual labour to ensure high quality of the final product. The pro