Silver Electrode Polarity Reversal for Water Supply Scaling

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Solution Overview

Problem

Existing water supply systems that use electrolysis to add metal ions for antimicrobial purposes face inefficiencies in ion release due to electrode scaling, particularly with silver ions, which are not effectively released at low concentrations, and this inefficiency is exacerbated by polarity reversal methods.

Innovation Solution

A water supply system that controls the average current to silver electrodes in proportion to water flow rate, with polarity reversal times based on cumulative charge, and decouples polarity reversal frequencies between silver and copper electrodes to minimize inefficiency, ensuring effective ion release while preventing scaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If polarity reversal is used to prevent electrode scaling, then electrode lifespan is improved, but silver ion release efficiency deteriorates

Engineering Contradiction:
Improveelectrode lifespanVSAvoidsilver ion release efficiency
Core Design Contradiction:
Duration of action of stationary objectVSProductivity

Solution Approach 1:

The system dynamically adjusts the polarity reversal timing based on cumulative charge rather than using fixed periodic reversal. The control unit calculates cumulative charge in real-time and triggers polarity reversal only when a predetermined charge threshold is reached, allowing the system to adapt to varying water flow rates and current conditions. This dynamic approach ensures that polarity reversal occurs at optimal moments for both preventing scaling and maintaining ion release efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback through cumulative charge measurement and monitoring. The control unit continuously measures the charge passed through the electrodes and uses this information to determine the precise moment for polarity reversal. This feedback mechanism ensures that polarity reversal is triggered based on actual electrochemical conditions rather than arbitrary time intervals, optimizing both electrode protection and ion release.

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If average current to silver electrodes is kept low to maintain safe ion concentration, then health safety is improved, but ion release efficiency deteriorates

Engineering Contradiction:
Improvehealth safetyVSAvoidion release efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system uses periodic voltage pulses applied to the silver electrodes to enhance ion release during specific time windows. By applying voltage periodically rather than continuously, the system achieves effective ion release during pulse periods while maintaining low average current levels. The cumulative charge-based polarity reversal works in conjunction with these periodic pulses to optimize the balance between safety and efficiency.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically controls the average current based on water flow rate measurements. When water flow is high, the system can safely increase the average current to improve ion release efficiency. When water flow is low, the system reduces current to maintain safe concentration levels. This dynamic adjustment optimizes the trade-off between health safety and ion release efficiency under varying operating conditions.

Inventive Principle:
Principle #15Dynamics

3Object-generated harmful factors

If polarity reversal frequency is increased to prevent scaling, then electrode scaling is reduced, but time loss from ineffectivity increases

Engineering Contradiction:
Improveelectrode scalingVSAvoidtime loss from ineffectivity
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The system uses cumulative charge feedback to determine polarity reversal timing, ensuring that reversals occur based on actual electrochemical conditions. This feedback mechanism prevents premature polarity reversal that would occur with fixed-frequency approaches, thereby reducing the number of ineffective periods while still preventing scaling. The system only reverses polarity when the cumulative charge threshold is reached, optimizing the balance between scaling prevention and operational effectiveness.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The polarity reversal frequency is dynamically adjusted based on operating conditions including water flow rate and current magnitude. Under conditions that promote scaling (high current, low flow), the system increases reversal frequency. Under normal conditions, the system uses lower reversal frequency based on cumulative charge accumulation. This dynamic adjustment minimizes unnecessary polarity reversals and their associated ineffective periods while maintaining effective scaling prevention.

Inventive Principle:
Principle #15Dynamics

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 ion concentration within safe limits, reduces electrode scaling, and enhances the efficiency of silver ion release, thereby providing effective antimicrobial treatment while handling variable water demand.

Implementation Method 1

silver ions are added to the water stream from a pair of silver electrodes

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

The polarity of a voltage difference that is applied between the silver electrodes is repeatedly reversed

Methodology Applied
Scientific EffectElectric Field: Electric Field

Data Source

PatentEP2108004B1Water supply system and method
Publication Date: 2019.06.19 HOLLAND WATER BV
  • EP2108004B1 patent drawingFigure 1
  • EP2108004B1 patent drawingFigure 2

AI summary

A water supply system supplies water to a water distribution system that draws a variable flow of water. To counteract micro-organisms silver is released into the water by pair of silver electrodes in a water conduit of the supply system. A parameter is measured that is indicative for water flow rate through the conduit. The average electric current supplied to the silver electrodes is controlled in proportion to the measured water flow rate. The polarity of a voltage difference applied between the silver electrodes is repeatedly reversed. To control the time of reversal a charge is computed that has been cumulatively applied to the silver electrodes since a previous polarity reversal of the voltage difference. The polarity of the voltage difference is reversed when the computed charge has reached a predetermined threshold.