Rechargeable Sacrificial Anode for Concrete Corrosion Protection
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Solution Overview
Problem
Existing galvanic anodes used for corrosion protection in steel reinforced concrete have limitations, including restricted useful life due to zinc mass and insufficient current output, which requires frequent maintenance and is costly, and are affected by exposure conditions and corrosion product buildup.
Innovation Solution
A method involving an impressed current anode and a sacrificial anode, where the sacrificial anode is recharged by depositing ions from a DC power supply, increasing its surface area and alkalinity, and using additives to limit gassing and dendritic growth, allowing for extended protection without frequent maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If ordinary galvanic anodes are used for corrosion protection, then the system is simple and requires no power supply, but the useful life is limited by zinc mass and current output is insufficient
Solution Approach 1:
The patent applies parameter changes by transitioning the anode system from a passive galvanic configuration to an active impressed current configuration. A DC power supply is introduced to provide external electrical energy, enabling the anode to deliver sustained current output beyond what is limited by zinc mass alone. This transforms the limiting factor from material quantity (zinc mass) to controllable electrical parameters (voltage, current, time), thereby extending the useful life of the corrosion protection system without proportionally increasing zinc content.
2Duration of action of stationary object
If the mass of zinc per anode is increased to extend useful life, then the duration of protection increases, but the device complexity and installation burden increase
Solution Approach 1:
The patent implements multi-functionality by introducing a DC power supply that serves multiple purposes: it provides impressed current to extend anode life, enables rechargeable anode systems where zinc can be electroplated back onto the anode surface, and allows for adjustable current output to match varying corrosion rates. This single power supply component replaces the need for simply increasing zinc mass, providing a versatile solution that addresses duration extension without proportional weight increase.
3Reliability
If regular maintenance and checking of power supply status is performed, then corrosion protection reliability is maintained, but the cost and operational complexity increase
Solution Approach 1:
The patent applies self-service through rechargeable anode systems where the DC power supply automatically recharges the sacrificial anode by electroplating zinc back onto the anode surface during periods when corrosion current is not required. The system monitors its own status and performs maintenance functions (recharging) automatically without requiring manual intervention, thereby maintaining high reliability while minimizing operational burden and cost.
4Use of energy by moving object
If solar panels are used to charge batteries for impressed current systems, then renewable energy is utilized, but the device complexity and initial cost increase
Solution Approach 1:
The patent uses the DC power supply as an intermediary component that can accept energy from various sources including solar panels, batteries, or direct DC connections. This intermediary power supply unit manages the complexity by providing a standardized interface between the energy source and the corrosion protection system, allowing solar panels to be integrated without redesigning the entire anode system. The power supply handles charge regulation, conversion, and distribution, isolating the complexity from the corrosion protection core functionality.
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 extends the operational life of the anode system by recharging the sacrificial anode, increasing current output, and maintaining effective corrosion protection with reduced maintenance costs and improved durability.
Implementation Method 1
providing a connection of the DC power supply so as to apply a potential difference between the impressed current anode and the sacrificial anode. Preferably the potential difference causes ions of the sacrificial anode material to move to the sacrificial anode.
Implementation Method 2
locating a sacrificial anode of a material which is less noble than the metal section in ionic contact with the ionically conductive material
Data Source
AI summary
Corrosion protection of steel in concrete is provided by locating an anode assembly including both a sacrificial anode and an impressed current anode in contact with the concrete and providing an impressed current from a power supply to the anode. The impressed current anode forms a perforated sleeve surrounding a rod of the sacrificial anode material with an activated ionically-conductive filler material between. The system can be used without the power supply in sacrificial mode or when the power supply is connected, the impressed current anode can be powered to provide an impressed current system and/or to recharge the sacrificial anode from sacrificial anode corrosion products.