Direct Concentrate Feed Reverse Osmosis Membrane Fouling
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Solution Overview
Problem
In liquid treatment systems using reverse osmosis membranes, the concentration of scale components in concentrated water can lead to scaling and fouling issues, reducing the efficiency and lifespan of the membranes, especially when the concentrate is stored and retained before being processed by the second RO membrane separator.
Innovation Solution
A configuration where the concentrate from the first RO membrane separator is directly fed to the second RO membrane separator with a pressure increasing means, such as a treated liquid pump and permeate or concentrate valves, to maintain efficient separation and prevent impurity accumulation, thereby suppressing fouling and scaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the concentrate is stored and retained before being processed by the second RO membrane separator, then the concentration of scale components increases, but this leads to scaling and fouling issues that reduce membrane efficiency and lifespan
Solution Approach 1:
The patent applies the skipping principle by eliminating the storage tank between the first and second RO membrane separators. The concentrate flows directly from the first separator to the second separator without being stored, thereby preventing the concentration of scale components that would occur during storage and avoiding subsequent scaling and fouling issues.
Solution Approach 2:
The patent extracts the harmful storage function from the system by removing the storage tank that was previously positioned between the two RO membrane separators. This extraction eliminates the source of scale component concentration and prevents the associated scaling and fouling problems.
2Loss of time
If a storage tank is installed between the first and second RO membrane separators, then the concentrate can be stored, but this leads to impurity accumulation and increased scaling risk
Solution Approach 1:
The patent eliminates the storage time by creating a direct flow path from the first RO membrane separator to the second RO membrane separator. The concentrate is rushed through the system without being stored, thereby preventing impurity accumulation and scaling that would occur during storage.
Solution Approach 2:
The patent removes the storage tank from the system architecture, extracting the harmful function of concentrate storage that leads to impurity accumulation and scaling. The direct connection between separators eliminates this harmful factor entirely.
3Productivity
If the recovery rate is increased to about 75 to 90%, then the amount of permeated water increases, but the concentration of scale components in concentrated water increases to the extent that scale occurs
Solution Approach 1:
The patent applies the skipping principle by eliminating the storage tank that would otherwise concentrate scale components. The direct flow path from the first to the second RO membrane separator prevents scale occurrence even when operating at high recovery rates of 75-90%, as the concentrate is processed immediately without concentration.
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 maintains efficient liquid treatment by preventing the accumulation of impurities and reducing the risk of fouling and scaling, ensuring stable operation and extending the membrane replacement time.
Implementation Method 1
a liquid treatment unit (26) that includes a reverse osmosis membrane (56) and in which a treated liquid is separated into a permeate that has permeated the reverse osmosis membrane and a concentrate other than the permeate
Implementation Method 2
a pressure increasing means that increases a liquid pressure of the concentrate, such that a state capable of separating into the recovered liquid and the waste liquid in the liquid recovery unit continues
Data Source
AI summary
A desalination apparatus 12 (liquid treatment apparatus) includes a first water treatment unit 26 (liquid treatment unit) that includes a reverse osmosis membrane and in which a treated liquid is separated into a permeate that permeates the reverse osmosis membrane and a concentrate other than the permeate, a water recovery unit 28 (liquid recovery unit) that includes a reverse osmosis membrane and in which the concentrate is separated into a recovered liquid that permeates the reverse osmosis membrane and a waste liquid other than the recovered liquid, and a pressure increasing means that increases a liquid pressure of the concentrate, such that a state capable of separating into the recovered liquid and the waste liquid in the liquid recovery unit continues, and that directly feeds the concentrate from the liquid treatment unit to the liquid recovery unit.