Auxiliary Cathode pH Control in Electrolytic Cell

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Solution Overview

Problem

Existing electrolytic cells for generating hypochlorous acid face challenges in maintaining the optimal pH range of 5-7, as they require complex hydraulic controls and recirculation or mixing of catholyte, which are costly and prone to failure due to scaling issues.

Innovation Solution

Incorporating an auxiliary cathode in the anode chamber separated by a small gap from the anode electrode, allowing dynamic control of current to the auxiliary cathode based on pH feedback, eliminating the need for additional hydraulic controls and maintaining the anolyte pH within the desired range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex hydraulic controls and recirculation systems are used to maintain optimal pH range, then pH control precision is improved, but device complexity increases and reliability decreases

Engineering Contradiction:
ImprovepH control precisionVSAvoidhydraulic control complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical hydraulic control systems with an electrical control system. A pH sensor monitors the anolyte pH level, and a controller automatically adjusts the power supply to the anode based on pH feedback, eliminating the need for complex hydraulic recirculation controls while achieving precise pH maintenance in the 5-7 range.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a closed-loop feedback control system where a pH sensor continuously monitors the anolyte pH level and feeds this information to a controller. The controller then adjusts the electrical power supplied to the anode accordingly, creating a self-regulating system that maintains optimal pH without complex hydraulic mechanisms.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If complex hydraulic recirculation systems are used to maintain optimal pH range, then pH control precision is improved, but reliability worsens due to scaling issues

Engineering Contradiction:
ImprovepH control precisionVSAvoidsystem reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent eliminates hydraulic recirculation systems by replacing them with electrical control. The controller modulates the electrical power to the anode based on pH sensor feedback, avoiding the scaling and maintenance issues associated with mechanical hydraulic components while maintaining reliable pH control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system becomes self-regulating through the feedback control mechanism. The pH sensor and controller work together to automatically adjust electrical power consumption based on real-time pH conditions, allowing the system to self-correct and maintain optimal operation without external mechanical intervention or complex hydraulic infrastructure.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If complex hydraulic controls are used for pH maintenance, then pH control precision is improved, but manufacturing cost increases

Engineering Contradiction:
ImprovepH control precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent reduces manufacturing costs by replacing expensive hydraulic control systems and recirculation infrastructure with a simple electrical control system. The pH sensor and controller provide precise pH maintenance through electrical power modulation, eliminating the need for costly hydraulic components, pumps, and associated maintenance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 design simplifies the system, enhances reliability and cost-effectiveness, and achieves higher electrolytic cell efficiencies with precise pH control, ensuring a consistent production of hypochlorous acid.

Implementation Method 1

electrolyzing a source liquid in an electrolytic device... anode chamber... produce an anolyte liquid from the source liquid... electrolysis reactions

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

level of current applied to the auxiliary cathode is adjusted in response to pH of an anolyte liquid... electrolysis reactions

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Data Source

PatentEP2914763B1Three electrode electrolytic cell and method for making hypochlorous acid
Publication Date: 2018.05.16 TENNANT CO
  • EP2914763B1 patent drawingFigure 1
  • EP2914763B1 patent drawingFigure 2
  • EP2914763B1 patent drawingFigure 3

AI summary

A method and apparatus are provided for electrolyzing a source liquid (54) in an electrolytic device (10, 50, 300). The electrolytic device (10, 50, 300) includes a first cathode (20, 320) in a cathode chamber (14); and an anode (22, 322) and a second, auxiliary cathode (24, 324) in an anode chamber (16). The anode chamber (16) and cathode chamber (14) are separated by a barrier (18, 316), and the anode (22, 322) and the auxiliary cathode (24, 324) are separated by a gap (26) that lacks a barrier. While electrolyzing the source liquid with the electrolytic device (10, 50, 300), a level of current applied to the auxiliary cathode (24, 324) is adjusted in response to pH of an anolyte liquid (36) produced from the source liquid (32, 54) by the anode chamber (16) to maintain the pH within a desired range.