Radial Flow Capacitive Deionization Cell Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Capacitive Deionization (CDI) systems for desalination face inefficiencies in ion removal and regeneration, leading to high salt content in regeneration water, which requires additional treatment and disposal challenges, especially when discharge into the sea is not feasible.
Innovation Solution
The CDI system employs a radial flow configuration with graphite electrodes and charge barriers, utilizing bus-rods and flow-conductors to ensure even water distribution and ion adsorption, allowing for efficient deionization and regeneration with reduced salt content in the effluent regeneration water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional flat plate electrodes with parallel flow are used, then the structure is simple and easy to manufacture, but the ion loading rate is low and regeneration water has high salt content
Solution Approach 1:
The patent employs radial flow configuration where water flows radially between circular electrodes instead of parallel flow between flat plates. This curvature change creates varying flow velocities across the electrode surface, enhancing ion loading rates while maintaining structural simplicity through the use of circular geometry and radial flow distributors.
Solution Approach 2:
The radial flow system creates dynamic flow conditions where water velocity varies continuously from the center to the periphery of the electrodes. This dynamic flow pattern improves ion mass transfer and loading efficiency compared to static parallel flow, while the overall device structure remains relatively simple through the use of radial flow distributors and circular electrode assemblies.
2Productivity
If conventional parallel flow configuration is used, then water distribution is uniform across electrodes, but ion removal efficiency is insufficient and regeneration water requires further treatment
Solution Approach 1:
The radial flow configuration between circular electrodes creates optimized flow paths that enhance ion removal efficiency. The curved geometry ensures better water distribution patterns and increased ion mass transfer, resulting in more effective ion removal and reduced salt content in regeneration water, minimizing the need for additional treatment.
Solution Approach 2:
The patent changes the flow configuration parameter from parallel to radial flow, and from rectangular to circular electrode geometry. These parameter changes optimize the hydrodynamics and electrostatic field distribution, leading to improved ion removal efficiency and reduced salt content in the regeneration stream.
3Productivity
If radial flow configuration with circular electrodes is used, then ion loading rates are enhanced and regeneration water salt content is reduced, but the device structure becomes more complex
Solution Approach 1:
While circular electrodes and radial flow configuration enhance ion loading rates, the patent maintains ease of manufacture by using simple circular geometries that can be easily fabricated from rolled sheets or extruded materials. The radial flow distributors can be constructed from simple radial vanes or perforated pipes, avoiding complex three-dimensional structures.
Solution Approach 2:
The electrode assembly is segmented into modular units with circular electrodes and radial flow distributors that can be manufactured separately and assembled. This segmentation allows for simplified manufacturing of individual components while achieving the performance benefits of radial flow configuration when assembled into the complete cell.
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 configuration enhances ion loading rates and reduces the salt content in regeneration water, minimizing the need for further treatment and improving the overall efficiency of the desalination process.
Implementation Method 1
Positive ions (e.g Na+ ions) migrate to the cathode, and negative ions (e.g Cl− ions) migrate to the anode. The adsorbed ions are then bound to the respective electrodes.
Implementation Method 2
Ions are adsorbed into the porous material of the electrodes, and are retained and stored therein
Data Source
AI summary
A water treatment apparatus comprising a stack of circular electrodes with a central through hole, the electrodes are supplied with electricity so as to form anodes and cathodes in alternating intercalation. The anodes and cathodes so arranged to lie in such close-spaced parallel face to face relationship as to form a capacitive deionization cell. Water to be treated is passed from the outside of the stack, radially inward through between the electrodes into the central through hole and then axially out of the stack.