Real-Time ORP Control for Hot Water Corrosion Inhibition

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for monitoring and controlling oxidation-reduction potential (ORP) in hot water systems are inadequate as they typically measure at room temperature and pressure, failing to detect real-time REDOX Stress events and leading to uncontrolled corrosion, which affects equipment life, reliability, and operational costs.

Innovation Solution

A method involving the definition of operational protective zones within hot water systems, where ORP probes measure real-time ORP at operating temperature and pressure, transmitting data to a controller, and adjusting the feed of active chemical species to maintain desired ORP settings, thereby controlling corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional room temperature ORP measurement methods are used, then measurement equipment is simpler and less costly, but real-time detection of REDOX Stress events at operating conditions is not achieved

Engineering Contradiction:
ImproveORP measurement accuracy at operating conditionsVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by measuring ORP at operating temperature and pressure conditions rather than at room temperature. This requires heating the sample to system operating temperature and measuring ORP in-situ within the hot water system, thereby achieving accurate detection of REDOX Stress events under actual operating conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional mechanical sampling and cooling systems with an in-situ measurement system that directly measures ORP within the hot water system at operating conditions. This eliminates the need for sample collection, transport, and cooling infrastructure, reducing mechanical complexity while improving measurement relevance.

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

2Reliability

If continuous monitoring of REDOX Stress events is implemented, then corrosion control is improved, but system complexity and cost increase

Engineering Contradiction:
Improvecorrosion control reliabilityVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements feedback control by continuously monitoring ORP and automatically adjusting chemical feed rates based on measured values. The system compares measured ORP against target ranges and modulates chemical dosing to maintain optimal corrosion protection, thereby improving reliability through closed-loop control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system achieves self-service by automatically detecting REDOX Stress events and adjusting chemical feed without requiring manual intervention. The automated control system continuously adapts to changing system conditions, eliminating the need for operator sampling and analysis while maintaining reliable corrosion control.

Inventive Principle:
Principle #25Self-service

3Loss of time

If sample cooling is performed before measurement, then measurement equipment requirements are reduced, but detection lag time increases

Engineering Contradiction:
Improvedetection lag timeVSAvoidsample temperature
Core Design Contradiction:
Loss of timeVSTemperature

Solution Approach 1:

The patent applies preliminary action by pre-heating the sample to operating temperature before ORP measurement. The sample is heated in advance within the measurement system, ensuring that the ORP reflects actual operating conditions without requiring post-sampling cooling, thereby eliminating detection lag time.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If chemical feed rates are adjusted manually, then system simplicity is maintained, but response to REDOX Stress events is delayed

Engineering Contradiction:
Improveresponse speed to corrosion eventsVSAvoidchemical feed control automation
Core Design Contradiction:
ProductivityVSExtent of automation

Solution Approach 1:

The patent implements automated feedback control where the ORP measurement directly controls chemical feed rate adjustments. The system continuously monitors ORP and automatically modulates chemical dosing in response to detected REDOX Stress events, achieving rapid response without manual intervention while maintaining system efficiency.

Inventive Principle:
Principle #23Feedback

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 enables real-time monitoring and control of ORP, effectively inhibiting corrosion by detecting and reacting to REDOX Stress events, improving system efficiency, reducing costs, and extending equipment life.

Implementation Method 1

measuring real-time oxidation-reduction potential at operating temperature and pressure

Methodology Applied
Scientific EffectOxidation-reduction potential measurement: Redox Reactions

Implementation Method 2

feed an effective amount of one or more active chemical species into the hot water system... effectively inhibiting corrosion by detecting and reacting to REDOX Stress events

Methodology Applied
Scientific EffectCorrosion inhibition through redox control: Redox Reactions

Data Source

PatentEP2179076B1Method for preventing corrosion in hot water systems
Publication Date: 2017.08.23 NALCO CO
  • EP2179076B1 patent drawingFigure 1
  • EP2179076B1 patent drawingFigure 2
  • EP2179076B1 patent drawingFigure 3

AI summary

Disclosed is a method of controlling a real-time oxidation-reduction potential in a hot water system to inhibit corrosion in the hot water system. The method includes defining one or more operational protective zones in the hot water system. One or more of the operational protective zones includes an oxidation-reduction potential probe that is operable to measure a real-time oxidation-reduction potential in the hot water system at operating temperature and pressure. The probe transmits the measured real-time potential to the controller, which assesses and interprets the transmitted potential to determine whether it conforms to an oxidation-reduction potential setting. If the measured potential does not conform the oxidation-reduction potential setting, the controller is operable to feed one or more active chemical species into the hot water system.