Multi-Chamber Reverse Osmosis System for Variable Water Quality
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Solution Overview
Problem
Existing reverse osmosis (RO) and nanofiltration systems face challenges in efficiently processing feed water of varying quality and managing different recovery rates, leading to reduced efficiency over time due to increasing salt concentrations.
Innovation Solution
A method and system that involves delivering feed water to multiple chambers, pumping it through RO or NF membranes, reducing pressure, and switching the concentrated feed stream between chambers upon efficiency reduction, with a desaturation unit to remove contaminants, allowing continuous cleaning and recycling, and pre-treating the feed water to maintain process efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If feed water is continuously circulated through a single RO/NF chamber, then the system can maintain operation, but the efficiency of the RO or NF process reduces due to increasing salt concentration in the chamber
Solution Approach 1:
The system divides the feed chamber into multiple separate chambers (first feed chamber and second feed chamber). When salt concentration in one chamber reaches a predetermined level, the system switches to using the other chamber, allowing the first chamber to be cleaned and refilled without interrupting the overall process. This segmentation enables continuous operation while maintaining process efficiency.
Solution Approach 2:
The system implements periodic switching between multiple feed chambers based on salt concentration levels. When the salt concentration in the current feed chamber reaches a predetermined maximum, the system periodically switches to an alternative chamber and initiates cleaning of the original chamber. This periodic action maintains continuous productivity while preventing efficiency degradation.
2Reliability
If the concentrated feed stream is removed and the chamber is cleaned, then the chamber efficiency is restored, but the system requires interruption or additional chambers to maintain continuous operation
Solution Approach 1:
The system uses multiple parallel feed chambers so that when one chamber requires cleaning, another chamber can continue processing. This segmentation allows maintenance activities to occur without interrupting overall system productivity.
Solution Approach 2:
The system discards the concentrated feed stream when it reaches maximum salt concentration and recovers the feed chamber by cleaning and refilling it with fresh feed water. This approach restores chamber efficiency while the parallel chamber maintains continuous productivity.
3Productivity
If multiple feed chambers are used with switching capability, then continuous operation and efficiency maintenance are achieved, but the system complexity increases
Solution Approach 1:
The system divides the feed handling into multiple independent chambers with individual circulation loops. Each chamber can operate independently, and the switching mechanism simply redirects flow between pre-existing chambers rather than requiring complex integrated control.
Solution Approach 2:
The system uses salt concentration sensors to monitor each chamber and provides feedback control for automatic switching. When a chamber reaches maximum salt concentration, the feedback signal triggers the switching mechanism and cleaning process, enabling automated operation that reduces complexity of manual management.
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 enables the effective cleaning and desalination of feed water of variable quality, maintaining process efficiency by recycling and cleaning chambers, and handling different recovery rates, thereby extending the system's operational lifespan and productivity.
Implementation Method 1
Desalination by reverse osmosis (RO) occurs when salt water solution is compressed against semi-permeable membranes at a pressure higher than its osmotic pressure
Implementation Method 2
Nanofiltration (NF) is also a semi-permeable membrane filtration-based method that uses nanometer sized cylindrical through-pores
Implementation Method 3
Examples include fluidised bed reactors, softeners, ion exchangers and/or an absorber
Implementation Method 4
Examples include fluidised bed reactors, softeners, ion exchangers and/or an absorber
Data Source
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AI summary
A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water (FW) to one or other of at least two feed chambers (2,4), each feed chamber having a delivery pipe (2i, 4i) for delivering feed water to a reverse osmosis or nanofiltration (8); a pump (6) to deliver the feed water from one of the chambers (2, 4) through its associated delivery pipe (2i, 4i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW);return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concentrated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmospheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).