Vacuum-Assisted Sealing for Spiral Wound Membrane Separators
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Solution Overview
Problem
Conventional separator assemblies face issues with telescoping and contamination due to the manual application of sealing adhesives, which is time-consuming and inefficient, especially in the fabrication of folded multilayer membrane assemblies used in fluid purification processes like reverse osmosis and ultrafiltration.
Innovation Solution
A method involving a central core element with separate permeate and concentrate exhaust conduits, where a membrane stack assembly is wound radially around the core with the feed carrier layer in contact with the concentrate conduit and the permeate carrier layer in contact with the permeate conduit, and a vacuum-assisted adhesive application and curing process to ensure reliable sealing without forming an outer surface, utilizing a specialized apparatus for efficient sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If sealing adhesive is applied manually before winding the membrane stack assembly, then the adhesive can be applied to seal the edges of the membrane layer, but the process is time-consuming and occupies up to 50% of overall operation time
Solution Approach 1:
The patent replaces manual mechanical adhesive application with an automated adhesive application device that can apply adhesive uniformly and efficiently to the membrane stack assembly edges, significantly reducing the time required for the sealing process while maintaining seal quality
Solution Approach 2:
The patent applies adhesive to the membrane stack assembly edges before the winding process begins, allowing the adhesive to be in place and ready for immediate sealing during winding, thereby eliminating the need for post-winding adhesive application and reducing overall process time
2Ease of operation
If sealing adhesive is kept in an uncured state to allow freedom of motion during winding, then the adhesive remains flexible during the winding process, but the folded multilayer membrane assembly becomes susceptible to telescoping and contamination
Solution Approach 1:
The patent applies adhesive to the membrane stack assembly edges before winding begins, so the adhesive is already in position and can immediately perform its sealing function during the winding process, eliminating the telescoping and contamination issues that arise when adhesive is applied after winding
Solution Approach 2:
The patent uses a support structure or mandrel during the winding process that maintains the proper spacing and alignment of the membrane layers, preventing telescoping while allowing the uncured adhesive to remain flexible during winding
3Reliability
If a folded multilayer membrane assembly is used to isolate the permeate carrier layer from the feed carrier layer, then contamination is prevented, but the structure becomes complex and difficult to manufacture
Solution Approach 1:
The patent divides the membrane assembly into distinct functional layers (feed carrier layer, membrane layer, permeate carrier layer) with clearly defined interfaces, and uses a spiral wound configuration that simplifies the overall structure while maintaining the necessary isolation between feed and permeate sides
Solution Approach 2:
The patent transitions from a folded three-dimensional structure to a two-dimensional spiral wound configuration that unrolls the membrane layers in a planar arrangement, simplifying manufacturing while maintaining the functional isolation of layers through their layered arrangement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the efficiency and reliability of the separator assembly fabrication by preventing contamination, reducing manufacturing time, and allowing the use of faster curing adhesives, thereby improving the overall process efficiency and cost-effectiveness.
Implementation Method 1
applying a negative pressure through at least one of the permeate exhaust conduit and the concentrate exhaust conduit so that the adhesive applied on the end surfaces of the wound assembly penetrates into the membrane stack assembly
Data Source
AI summary
The present invention provides a method and apparatus for fabricating a separator assembly. The method comprises: providing a central core element comprising at least one concentrate exhaust conduit and at least one permeate exhaust conduit; disposing a first portion of a membrane stack assembly comprising a permeate carrier layer, a membrane layer, and a feed carrier layer within the central core element such that the concentrate exhaust conduit and permeate exhaust conduit are separated by the first portion of the membrane stack assembly; radially winding a second portion of the membrane stack assembly around the central core element; and sealing the wound assembly comprising two opposing end surfaces made of the membrane stack assembly by applying an adhesive on both end surfaces of the wound assembly; and applying a negative pressure inside the central core element so that the adhesive penetrates into the membrane stack assembly.