Membrane Filtration Installation with Adjustable Block Order
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing membrane-based filtration systems for producing drinking water either produce water that is entirely demineralized, requiring remineralization, or fail to adequately remove micropollutants and allow excessive monovalent ions, necessitating costly post-mineralization steps and additional equipment.
Innovation Solution
The use of a membrane-based filtration installation that combines reverse-osmosis membranes and nanofiltration membranes in the same or different pressure tubes, allowing for adjustable configurations to achieve optimal rejection of calcium and micropollutants while maintaining a target water hardness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reverse-osmosis membranes are used for filtration, then micropollutants and solutes are effectively retained, but the produced water is entirely demineralized requiring post-mineralization
Solution Approach 1:
The patent combines reverse-osmosis membranes and nanofiltration membranes within the same pressure tube, creating an integrated filtration system that simultaneously achieves micropollutant removal and maintains water hardness, eliminating the need for separate post-mineralization equipment
Solution Approach 2:
The system uses a composite membrane configuration with two different membrane types (reverse-osmosis and nanofiltration) working together in series within the same pressure tube, leveraging the complementary properties of each membrane type to achieve both high rejection and adequate mineral content
2Quantity of substance
If nanofiltration membranes are used for filtration, then water hardness is maintained, but micropollutant removal is insufficient and monovalent ions are excessive
Solution Approach 1:
The patent merges nanofiltration membranes and reverse-osmosis membranes in the same pressure tube, combining the hardness-maintaining capability of nanofiltration with the high rejection capability of reverse-osmosis to achieve both objectives simultaneously
Solution Approach 2:
The pressure tube is segmented into multiple filtration stages with different membrane types, where nanofiltration membranes handle hardness maintenance and reverse-osmosis membranes handle micropollutant removal, with each segment performing its specialized function
3Productivity
If multiple filtration blocks with numerous pressure tubes are used, then production capacity increases, but energy consumption and system complexity increase
Solution Approach 1:
The patent merges multiple membrane types within single pressure tubes, reducing the total number of pressure tubes and filtration blocks needed to achieve a given production capacity, thereby lowering the overall energy consumption and system complexity
Solution Approach 2:
The pressure tube design with multiple membrane types achieves multiple functions (micropollutant removal, hardness maintenance, and adequate flow production) within a single unit, reducing the number of separate filtration stages required
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 eliminates the need for post-mineralization, reduces energy consumption, and maintains consistent water hardness despite variations in temperature or calcium content, while effectively removing micropollutants and optimizing hydraulic yields.
Implementation Method 1
reverse-osmosis membranes have an even denser structure. Among reverse-osmosis membranes, low-pressure reverse-osmosis membranes (LPRO) are distinguished that have a permeability greater than that of the reverse-osmosis membranes used to desalinate seawater (RO)
Implementation Method 2
nanofiltration membranes are distinguished from low-pressure reverse-osmosis membranes by the fact that they only partially retain the monovalent ions
Data Source
AI summary
Installation for the pressurised filtration of liquid with a view to producing drinking water, comprising at least one membrane-based drinking-water production unit (MPU), each MPU comprising: a plurality of filtration blocks each containing a bundle of pressure tubes mounted in parallel, each pressure tube accommodating at least two membrane-based filtration modules with spiral membranes or hollow-fibre membranes mounted in series, means (20) for feeding the liquid that is to be filtered, means for removing the filtered liquid, and means (30) for removing the concentrate, characterised in that the membranes of the filtration modules are of at least two different types selected from the group consisting of reverse-osmosis membranes and low-pressure reverse-osmosis membranes (4-6), on the one hand, and nanofiltration membranes (1-3) on the other hand, and in that at least one MPU comprises means (21-26) making it possible to alter the order in which the blocks of pressure tubes that it groups together are supplied with fluid. The method consists in supplying the filtration blocks of at least one MPU in a first order of supply in which the tubes containing nanofiltration membranes are at the head of the MPU and then in supplying the pressure tubes in a second order of supply in which the pressure tubes containing reverse-osmosis membranes or low-pressure reverse-osmosis membranes are at the head of the MPU.