High-Pressure Spiral Wound Membrane Module for High-Concentration RO
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seawater reverse osmosis membranes struggle to achieve high concentration end points due to lower salt permeability and insufficient permeate flow under high pressure, while brackish water membranes can achieve better flux and concentration end points but face osmotic pressure challenges.
Innovation Solution
A spiral wound membrane module using a brackish water RO or NF membrane with a permeate carrier having a narrow spacing between membrane contacting elements, operated at high feed pressures, to manage osmotic pressure and prevent deformation, achieving high water and salt permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If seawater reverse osmosis membranes are used, then salt permeability is reduced, but permeate flow becomes insufficient under high pressure to achieve high concentration end points
Solution Approach 1:
The patent changes the operating parameters by using brackish water RO/NF membranes with higher water permeability (A-value ≥ 8×10^-5 cm/s/bar) and operates at high feed pressures (50-120 bar) to achieve both high permeate flow and high concentration end points simultaneously, resolving the contradiction between salt permeability reduction and permeate flow sufficiency
2Productivity
If brackish water membranes are operated at high pressure, then flux and concentration end points improve, but osmotic pressure challenges arise
Solution Approach 1:
The patent applies preliminary action by using a permeate carrier with narrow spacing (215 μm or less at wide parts, 175 μm average) between membrane contacting elements to pre-establish structural support that prevents membrane deformation under high osmotic pressure, enabling high flux operation at 50-120 bar
3Reliability
If permeate carrier has narrow spacing between membrane contacting elements, then membrane deformation is prevented, but manufacturing complexity increases
Solution Approach 1:
The patent uses a permeate carrier made from porous or knit fabric materials with controlled pore sizes and structures that naturally provide the required narrow spacing (215 μm or less) while maintaining manufacturability through established textile and filtration material production methods
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
The module achieves higher flux and concentration end points, exceeding 130 g/L, while maintaining effective permeate flow and preventing membrane deformation under high pressure conditions.
Implementation Method 1
A spiral wound membrane module having a brackish water RO or NF membrane
Implementation Method 2
A spiral wound membrane module having a brackish water RO or NF membrane
Implementation Method 3
a permeate carrier having a narrow spacing between membrane contacting elements
Implementation Method 4
The membrane may have water permeability (A-Value) of at least 8*10−5 cm/s/bar at 25° C.
Implementation Method 5
The membrane may have salt diffusion rate, alternatively called salt permeability, (B-Value) of at least 0.5*10−5 cm/s at 25° C.
Data Source
AI summary
A spiral wound membrane module has a brackish water RO or NF membrane combined with a permeate carrier having a narrow spacing between membrane contacting elements. The membrane may have water permeability (A-Value) of at least 8*10−5 cm/s/bar at 25° C. The membrane may have salt diffusion rate (B-Value) of at least 0.5*10−5 cm/s at 25° C. The permeate carrier may have a density of 54 wales per inch or more of a gap between adjacent ribs of 215 um or less. The permeate carrier may have a channel cross-sectional area of 16*10−9 m2 or more. Water is fed to the module at a high feed pressure, for example a pressure of at least 50 bar, optionally up to 120 bar. Retentate may be discharged at a concentration of 100 g/L, 130 g/L, or 150 g/L or more.