Split Chamber Zero Resistance Ammeter for Microbial Corrosion Detection

Solution Overview

Problem

Current methods fail to accurately identify microbially influenced corrosion (MIC) in pipelines, leading to unnecessary application of biocides and increased costs, as they cannot distinguish between microbial presence and corrosion causation, and are ineffective against uncultivated microorganisms, resulting in resource wastage and potential acceleration of corrosion.

Innovation Solution

A split chamber zero resistance ammeter (SC-ZRA) apparatus measures current flow between a test electrode in contact with a corrosive medium and a sterilized control electrode to calculate predictive mass loss, combined with electrochemical impedance spectroscopy (EIS) to assess pitting corrosion and corrosion resistance, allowing for targeted biocide treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If biocides are applied when microorganism growth is detected, then microbial presence is addressed, but resources are wasted when microorganisms are not responsible for corrosion and corrosion may be accelerated

Engineering Contradiction:

Improvecorrosion protectionVSAvoidbiocide resources

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent replaces conventional microbiological detection methods with electrochemical measurement techniques (zero resistance ammetry and electrochemical impedance spectroscopy) to directly detect corrosion-causing mechanisms. This substitution allows differentiation between mere microbial presence and actual corrosion causation, enabling targeted biocide application only when electrochemical signals confirm active corrosion processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system implements continuous monitoring of electrochemical parameters (current flow, impedance) to provide real-time feedback on corrosion activity. This feedback mechanism enables dynamic adjustment of biocide treatment decisions, applying treatment only when electrochemical signals indicate active corrosion, thereby avoiding unnecessary biocide application and resource waste.

Inventive Principle:

Principle #23Feedback

2Difficulty of detecting and measuring

If conventional detection methods are used to identify MIC, then microbial presence can be detected, but accurate differentiation between microbial presence and corrosion causation cannot be achieved

Engineering Contradiction:

Improvemicrobial presence detectionVSAvoidcorrosion causation identification

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent replaces conventional microbiological detection methods with electrochemical measurement techniques (zero resistance ammetry and electrochemical impedance spectroscopy) to directly detect corrosion-causing mechanisms. This substitution allows differentiation between mere microbial presence and actual corrosion causation, enabling targeted biocide application only when electrochemical signals confirm active corrosion processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electrochemical parameters (current flow, impedance) as intermediary measurements that bridge the gap between microbial presence and corrosion causation. These electrochemical signals serve as mediators that directly reflect active corrosion processes at the metal surface, providing more precise information than direct microbial detection alone.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If sampling is performed in the fluid flowing in the pipeline, then microorganisms can be quantified, but analysis of what is occurring at the metal surface is limited

Engineering Contradiction:

Improvesampling accessibilityVSAvoidmetal surface corrosion analysis

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces fluid sampling methods with direct electrochemical measurement techniques that interface with the metal surface. By using zero resistance ammetry and electrochemical impedance spectroscopy directly on pipeline coupons, the system eliminates the need for complex sampling and transport procedures while providing direct measurement of corrosion processes at the metal surface.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electrochemical parameters (current flow, impedance) as intermediary measurements that bridge the gap between microbial presence and corrosion causation. These electrochemical signals serve as mediators that directly reflect active corrosion processes at the metal surface, providing more precise information than direct microbial detection alone.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method effectively differentiates between microbial presence and corrosion causation, reducing resource wastage and accurately assessing corrosion rates, thereby optimizing biocide application and minimizing unnecessary treatments.

Implementation Method 1

measuring current flow between a test electrode and a control electrode in a split chamber zero resistance ammeter (SC-ZRA) apparatus

Methodology Applied

Scientific EffectElectrical current flow measurement: Ohm's Law

Implementation Method 2

measuring the resistance, Rpit, of a surface of the subject metal that is undergoing pitting corrosion, using an electrochemical impedance spectroscopy apparatus

Methodology Applied

Scientific EffectElectrochemical impedance measurement: Electrical Resistance

Implementation Method 3

an ionic connection between the test sample and the control sample to allow ion flow

Methodology Applied

Scientific EffectIon transport: Ion Exchange

Data Source

PatentUS11674885B2Apparatus and methods to detect and assess microorganism influenced corrosion and pitting corrosion

Publication Date: 2023.06.13 THE UNIVERSITY OF AKRON

AI summary

A method to detect and assess microorganism influenced corrosion includes measuring current flow between a test electrode and a control electrode in a split chamber zero resistance ammeter apparatus and calculating a predictive difference in mass loss between the test electrode and the control electrode based on that current over time; and measuring the resistance, Rpit, of a surface of the subject metal to assess pitting corrosion using an electrochemical impedance spectroscopy apparatus.