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US 2008/0164202 A1Published application
Manufacture Of Membranes For Desalination And Filtration
AssigneeGrahamtek Technologies Singapore Pte Ltd
InventorWilliam Graham
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AssigneeGrahamtek Technologies Singapore Pte Ltd
InventorWilliam Graham
Estimating the term…
A spiral wound membrane is disclosed which comprises an elongate web of a material which allows water to pass through but inhibits the passage of solids and/or dissolved solids. The web has been folded to zig-zag form to produce a stack of layers (68.1, 68.2 etc.) joined to one another by reverse bends (72, 74). A perforated tube (18) is provided, the ends of the web forming the stack being secured to the tube. The stack is wound around the tube and there are spacers (58, 62) between the layers, (68.1, 68.2 etc.). The spacers hold the layers apart to form water flow passages (56, 60). Alternate water flow passages (60) have the ends thereof transverse to the bends (72, 74) sealed closed. These passages are also closed by reverse bends (74) at the radially outer ends thereof. Along their radially inner edges thereof these passages are in communication with the perforations (54) of the tube (20). Strengthening tapes (70) are provided inside the bends (72, 74).
A spiral wound membrane which comprises an elongate web of a material which allows water to pass through but inhibits the passage of solids and/or dissolved solids and which has been folded to zig-zag form to produce a stack of layers joined to one another by reverse bends, a perforated tube, the ends of the web forming the stack being secured to the tube, said stack being wound around the tube, there being spacers between the layers, the spacers holding the layers apart to form water flow passages, alternate water flow passages having the ends thereof transverse to said bends sealed closed, said alternate passages being closed by reverse bends at the radially outer ends thereof and being in communication with the perforations of the tube at the radially inner ends thereof.
A method of manufacturing a spiral wound membrane which comprises zig-zag folding an elongate web thereby to produce a stack of layers with reverse bends in the web between layers, the web being of a material which allows water to pass through but inhibits the passage of solids and/or dissolved solids, inserting a spacer into the gap between each top layer of the stack and the layer which is being placed on it, said spacers being inserted alternately from opposite sides of the stack, attaching the free ends of the top and bottom layers of the stack to a perforated tube, and winding the stack about the tube.
Dependencies are inferred from the claim text.