Sacrificial cathodic protection system
First Claim
1. In a sacrificial anode type of cathodic protection system, said system comprising a cargo-ballast tank of a petroleum product tank ship subject to being contacted periodically by an electrolyte, the improvement comprisinga field effect type metal oxide silicon semi-conductor device having a pair of junctions and a gate,an anode for contacting said electrolyte to provide said protection,an electrode for contacting said electrolyte,a comparator,first circuit means for connecting one junction of said device to said structure,second circuit means for connecting the other junction of said device to said anode,third circuit means for connecting said electrode to said comparatorfourth circuit means for connecting the output of said comparator to said gate,fifth circuit means for connecting the input of said comparator to one of said junctions of said device, andsixth circuit means for connecting the other of said junctions of said device to said comparator.
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Accused Products
Abstract
Corrosion protection is provided to a metallic structure by a sacrificial anode system. A current control element is used to achieve fast and adequate corrosion protection under changing conditions, while excess current flow is minimized to extend anode life and avoid overprotection. The basic advantages of sacrificial anode systems such as simplicity and autonomy are retained. The system employs a field effect or a MOS (metal oxide silicon) semiconductor device to act as the current control element.
27 Citations
1 Claim
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1. In a sacrificial anode type of cathodic protection system, said system comprising a cargo-ballast tank of a petroleum product tank ship subject to being contacted periodically by an electrolyte, the improvement comprising
a field effect type metal oxide silicon semi-conductor device having a pair of junctions and a gate, an anode for contacting said electrolyte to provide said protection, an electrode for contacting said electrolyte, a comparator, first circuit means for connecting one junction of said device to said structure, second circuit means for connecting the other junction of said device to said anode, third circuit means for connecting said electrode to said comparator fourth circuit means for connecting the output of said comparator to said gate, fifth circuit means for connecting the input of said comparator to one of said junctions of said device, and sixth circuit means for connecting the other of said junctions of said device to said comparator.
Specification
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- Resources
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Current AssigneeS.A. Texaco Belgium N.V.
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Original AssigneeS.A. Texaco Belgium N.V.
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InventorsMaes, Jean P.
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Primary Examiner(s)Tung, T.
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Application NumberUS06/217,268Time in Patent Office867 DaysField of Search204/147, 204/148, 204/196, 204/197, 307/577, 307/448US Class Current204/196.04CPC Class CodesC23F 13/04 Controlling or regulating d...G01R 17/06 Automatic balancing arrange...
