Electromagnetic Corrosion Protection via In-Situ Passive Oxide Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing corrosion protection methods for metallic structures, such as cathodic protection, are costly, require high energy consumption, and are vulnerable to interference corrosion, especially in low conductivity environments, and lack a long-lasting protective coating solution for both buried and immersed structures.
Innovation Solution
A system utilizing time varying electromagnetic waves with a generator and electric power source to energize metallic structures, forming in-situ passive oxidized species like magnetite or cuprous oxide, which acts as a self-repairing, low-maintenance protective coating, independent of electrolyte conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cathodic protection is applied to protect metallic structures, then corrosion protection is achieved, but high energy consumption is required especially in low conductivity environments
Solution Approach 1:
The patent changes the fundamental parameter from direct current (DC) to time-varying electromagnetic waves with frequencies ranging from audio to radio frequencies. This parameter change allows the system to achieve corrosion protection through electromagnetic induction and electrochemical reactions without requiring high driving voltages, thus reducing energy consumption especially in low conductivity environments where traditional cathodic protection struggles.
Solution Approach 2:
The patent replaces the traditional mechanical/electrical cathodic protection system with an electromagnetic field-based system. Instead of using DC current flow through electrolytes to protect structures, the invention uses time-varying electromagnetic waves that induce currents and electrochemical reactions directly on the metal surface, eliminating the need for high voltage driving and reducing energy consumption.
2Use of energy by moving object
If protective coating is applied to reduce protective current requirement, then current density is reduced, but coating cost and renewal cost increase
Solution Approach 1:
The patent employs a self-forming protective mechanism where time-varying electromagnetic waves induce electrochemical reactions that create a protective oxide layer directly on the metal surface. This self-forming coating eliminates the need for external coating application and renewal, reducing both initial coating costs and ongoing maintenance costs while simultaneously reducing protective current requirements.
Solution Approach 2:
The system performs preliminary action by continuously forming and maintaining a protective oxide layer on the metal surface through electromagnetic induction before corrosion can occur. This preventive approach eliminates the need for subsequent coating renewal and reduces the overall protective current needed throughout the structure's service life.
3Reliability
If sacrificial anode is used for cathodic protection, then corrosion protection is provided, but anode consumption and replacement are required
Solution Approach 1:
The patent replaces the consumable sacrificial anode system with a non-consumable electromagnetic field generation system. Instead of relying on anode material consumption to provide protection, the invention uses electromagnetic waves to induce protective effects, eliminating the need for anode replacement and extending system service life to match the protected structure's lifespan.
Solution Approach 2:
The system changes from a chemical consumption-based protection method (sacrificial anode dissolution) to an electromagnetic field-based method. By using time-varying electromagnetic waves with adjustable frequencies and amplitudes, the system provides continuous protection without material consumption, thereby extending the duration of action to match the structure's service life.
4Ease of operation
If high driving voltage is applied to overcome low electrolyte conductivity, then protective current is driven out, but energy consumption increases
Solution Approach 1:
The patent replaces the voltage-driven current delivery system with an electromagnetic induction system. Instead of applying high driving voltages to push current through high-resistance low conductivity electrolytes, the invention uses time-varying electromagnetic waves that induce currents directly on the metal surface through electromagnetic coupling, bypassing the electrolyte resistance issue and reducing energy consumption.
Solution Approach 2:
The electromagnetic field acts as an intermediary between the power source and the protected structure. Rather than directly forcing current through the problematic low conductivity electrolyte, the system uses electromagnetic waves as an intermediate carrier that can penetrate and induce effects without being significantly hindered by electrolyte conductivity, thus delivering protective current efficiently with lower energy input.
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 provides long-lasting, energy-efficient corrosion protection with reduced maintenance, capable of achieving full cathodic protection potential quickly and effectively, even in low conductivity environments, and covers the entire structure surface, including hard-to-reach areas.
Implementation Method 1
a generator (120) for generating electromagnetic wave having a time varying frequency
Implementation Method 2
the metallic structure is energized to form in-situ a passive oxidized species of the metal on a surface of the metallic structure
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention provides a system for providing corrosion protection of a metallic structure using time varying electromagnetic wave, comprising: a generator for generating electromagnetic wave having a time varying frequency, said generator having at least two output terminals in electrical connection respectively with first and second excitation sites which are positioned in a spaced manner on the metallic structure, allowing for subjecting the metallic structure to the electromagnetic wave; and an electric power source connected to the generator for applying a driving voltage to the generator to drive the generation of the electromagnetic wave; wherein the driving voltage and/or the frequency of the electromagnetic wave are selected such that the metallic structure is energized to form in-situ a passive oxidized species of the metal on a surface of the metallic structure, which species is insusceptible to corrosion. The invention also provides a method for providing corrosion protection of a metallic structure using time varying electromagnetic wave.