Propeller Arrangement for Marine Cathodic Protection
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Solution Overview
Problem
Existing cathodic protection systems for marine vessels, particularly smaller ones, face challenges such as increased drag, limited space for ICCP units, aesthetic issues, and complexity in electrically connecting propellers for corrosion protection.
Innovation Solution
A propeller arrangement using impressed current cathodic protection (ICCP) with slip ring connectors to eliminate the need for physical wiring, allowing propellers to function as both anodes and cathodes, and incorporating a reference electrode for effective corrosion and marine growth protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If externally mounted ICCP units are used for corrosion protection, then corrosion protection is provided, but drag increases and space is consumed
Solution Approach 1:
The patent combines the propeller with the ICCP system by making the propeller itself electrically isolated and connectable to the power source, merging the propulsion function with the cathodic protection function into a single integrated component, thereby eliminating the need for separate externally mounted ICCP units
Solution Approach 2:
The propeller is designed to serve dual functions: propulsion and cathodic protection. The propeller can be electrically connected to the power source through slip ring connectors, enabling it to function as an active component in the ICCP system while maintaining its primary propulsion role
2Reliability
If externally mounted ICCP units are used for corrosion protection, then corrosion protection is provided, but available space on the transom is reduced
Solution Approach 1:
The patent merges the ICCP functionality into the propeller assembly itself, eliminating the need for separate externally mounted units on the transom. The propeller becomes the active component, freeing up transom space for other uses
3Reliability
If propellers are electrically connected to power source for cathodic protection, then corrosion protection is provided, but wiring complexity increases
Solution Approach 1:
The patent introduces slip ring connectors as an intermediary mechanism between the rotating propeller and the stationary power source. These slip rings provide continuous electrical connection without requiring complex wiring arrangements, simplifying the overall system while enabling cathodic protection
4Reliability
If propellers are used as anodes in ICCP system, then corrosion protection is provided, but marine growth protection is reduced
Solution Approach 1:
The patent enables dynamic switching of the propeller's electrical connection state. The propeller can be connected to the power source when corrosion protection is needed and disconnected when marine growth protection is the priority, allowing adaptive response to different operational conditions and protection requirements
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
The solution reduces drag, conserves space, avoids aesthetic issues, and provides efficient corrosion and fouling protection for marine vessels by using propellers as active anodes and cathodes, while eliminating wiring-related vibration issues.
Implementation Method 1
the driveline housing comprises a slip ring connector arranged to transfer current from the driveline housing to the propeller
Implementation Method 2
An efficient way of providing corrosion and marine growth protection is the use of a method termed impressed current cathodic protection (ICCP)
Implementation Method 3
each electrically isolated propeller is electrically connected to a slip ring connector, which slip ring connector is in electrical connection with the positive terminal
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
The invention relates to a propeller arrangement in a cathodic protection system for a marine vessel (100) with a marine propulsion system, which cathodic protection system comprises a direct current power source (110; 210) with a positive terminal (111; 211). The propulsion system comprises at least one driveline housing (101; 201) at least partially submerged in water; a torque transmitting drive shaft (106; 232, 233) extending out of the driveline housing (101; 201); and at least one propeller (102, 103; 202, 203) mounted on the drive shaft (106; 232, 233). According to the invention, the at least one propeller (102, 103; 202, 203) is electrically isolated from its drive shaft (106; 232, 233). Each electrically isolated propeller (102, 103; 202, 203) is electrically connected to a slip ring connector(313a, 313b), which slip ring connector(313a, 313b)is in electrical connection with the positive terminal (111; 211).The invention further relates to a vessel provided with such a propeller arrangement.