Abstract: The invention provides a heater arrangement and method for heating a liquid, wherein the heater comprises a heating element, wherein the method comprises (i) heating the liquid in the heater wherein the heating element is in contact with the liquid, and (ii) applying a potential difference between the heating element and a counter electrode, wherein the potential difference has an AC component whereby the potential difference varies with an AC frequency in the range of 0.01-100 Hz and wherein the potential difference is applied with a cycle time, wherein the potential difference has a sign during a first part of the cycle time that is opposite of the sign of the potential difference during a second part of the cycle time, and wherein during one or more of the first part of the cycle time and the second part of the cycle time, the potential difference temporarily changes sign.

Abstract: Communications systems are provided for use with an impressed current cathodic protection (ICCP) system having single or multiple ICCP components. A pipeline may be provided by connecting multiple pipeline sections together as an integrated pipeline where each section has an associated ICCP system. A communications signal comprising an AC signal is impressed on the pipeline and received by receivers associated with power supplies associated with each ICCP system. Upon reception of the AC signal, a controllable switch is operated within the power supplies to synchronously disconnect them from their power source and thereby enable accurate testing of the ICCP system.

Abstract: The invention is a multiple-structure cathodic protective system that includes multiple voltage-controlled outputs to protect multiple structures with a common ground bed, or a single structure with multiple anode ground beds. Each output feeds an individual cable that is powered by independent pulse-width-modulated voltage power supplies. Current through the cables is monitored and the PWM control compensates to maintain the correct amount of current for maximum protection and long life.

Abstract: A method for electrode renewal, for use in an electrolytic processing chamber for a liquid therein wherein the processing includes, for a pair of electrodes in the chamber, placing a positive voltage on one electrode in the chamber and placing a like negative voltage on another electrode in the chamber. It has been common practice to reverse the voltage between these electrodes in order to re-dissolve the buildup thereon. Now, the present inventor has observed that a voltage passing through or across an electrode will cause some minor cavitations on the electrode surface between the contact junctures of the voltage, and apparently the cavitations results in the buildup there-on detaching in bulk; which is much faster than the heretofore known re-dissolve processes of electrode renewal.

Abstract: An active cathodic protection system, the apparatus comprising a rectifier element with at least one electrical connection to a source of electrical current, the rectifier element associated with a direct current positive (+) output terminal for electrical connection of via an anode connector to a consumable anode, a direct current negative (?) output terminal for electrical connection via a cathode connector to the structure to be protected, grounding means for electrical grounding of the apparatus and anti-cross connection means for preventing the continuing flow of electrical current when the anode connector is associated with the negative output terminal and the cathode connector is associated with the positive output terminal. The cathodic protection system also includes a microprocessor controlled device for shutting the system if an improper current is sensed.

Abstract: The present invention relates to an electrical device for impeding corrosion of a metal body. The electrical device includes a driver circuit including at least one inductive component. The driver circuit is suitable for driving one or more pads coupled to the metal body so that corrosion of the metal body is impeded. A control circuit is provided for controlling the operation of the driver circuit. A feedback circuit provides feedback from the driver circuit to the control circuit. The driver circuit can operate as a resonant circuit, owing to the at least one inductive component, and ballast energy applied to the pads.

Abstract: This invention relates to protection of a metal component exposed to a corroding medium. One or more of the following are provided: cathodic protection, measuring of a condition of the component, retarding or avoiding of fouling. A sacrificial anode is used as the energy source such that the electric circuit can provide a pulsating current, voltage, automatically adapted current, or protecting potential. Germanium solid state elements are used.

Abstract: An electrode system for preventing biofouling of a surface either is applied directly onto the surface of an aquatic vehicle or structure, if the surface is non-conducting; or is applied onto an insulating paint layer on the surface, if the surface is conducting; or is embedded in a layer of electrically non-conducting material. The electrode system includes two alternating sets of electrodes in the form of spaced, parallel strips made from any conductive material, preferably a conductive coating, the first set being provided with a number n of parallel electrodes, and the second set being provided with a number n?1 of parallel electrodes, with the positions of the electrodes of the first set alternating with the positions of the electrodes of the second set. The geometry of the electrodes is such that when the voltage is applied, the electric field radiates outwardly parallel to the surface of the structure.

Abstract: First and second axial current meters (ACM) are mechanically connected to a well casing just above and below a corrosive zone and a master axial current meter (MACM) is connected to the casing at the earth's surface, the MACM periodically obtaining measurements of axial current from the ACMs to determine how much cathodic protection current is to be applied to the casing to avoid corrosion.

Abstract: An apparatus for prevention of corrosion in metal objects uses a capacitively coupled fastener or pad attached to a metal body being protected from corrosion. The metal body and the negative terminal of a source of DC voltage (battery) are grounded. The positive terminal of the source of DC voltage is connected to electronic circuitry that imparts pulses of low voltage DC through the capacitor to the fastener. These pulses of electrical current inhibit the oxidation of the metal object by providing a source of electrons to the oxidizing chemicals in contact with the metal. The electronic circuitry includes a reverse voltage protector to prevent the application of reverse source voltage. The circuitry also includes a power conditioner to supply a constant DC voltage to a microprocessor. The microprocessor generates pulses of DC signals that are amplified by a pulse amplifier and imparted to the conductive facing of the pad. For larger objects, a first and second cable are attached to a metal object.

Abstract: An electrode system for preventing biofouling of a surface either is applied directly onto the surface of an aquatic vehicle or structure, if the surface is non-conducting; or is applied onto an insulating paint layer on the surface, if the surface is conducting; or is embedded in a layer of electrically non-conducting material. The electrode system includes two alternating sets of electrodes in the form of spaced, parallel strips made from any conductive material, preferably a conductive coating, the first set being provided with a number n of parallel electrodes, and the second set being provided with a number n-1 of parallel electrodes, with the positions of the electrodes of the first set alternating with the positions of the electrodes of the second set. The geometry of the electrodes is such that when the voltalge is applied, the electric field radiates outwardly parallel to the surface of the structure.

Abstract: A main anode and a pilot anode are mounted on a coating film of a metal structure, a cathode is mounted on a metal based material of the metal structure, a predetermined voltage is applied from the pilot anode to the metal structure, a magnitude of corrosion protection current of the metal structure is read from a current value of the pilot anode varying with variation of corrosion environment of the metal structure, the application voltage of the main anode is increased or decreased in accordance with the current value, whereby providing a cathodic protection method and apparatus for a metal structure capable of expanding protectable area by a single anode to a maximum without causing over-corrosion protection.

Abstract: An apparatus for prevention of corrosion in metal objects uses a capacitively coupled fastener or pad attached to a metal body being protected from corrosion. The metal body and the negative terminal of a source of DC voltage (battery) are grounded. The positive terminal of the source of DC voltage is connected to electronic circuitry that imparts pulses of low voltage DC through the capacitor to the fastener. These pulses of electrical current inhibit the oxidation of the metal object by providing a source of electrons to the oxidizing chemicals in contact with the metal. The electronic circuitry includes a reverse voltage protector to prevent the application of reverse source voltage. The circuitry also includes a power conditioner to supply a constant DC voltage to a microprocessor. The microprocessor generates pulses of DC signals that are amplified by a pulse amplifier and imparted to the conductive facing of the pad. The invention also includes a battery voltage monitor and a power indicator.

Abstract: An electro-chemical process for rehabilitating steel reinforced concrete, wherein a distributed flow of electrical current is established between internally embedded reinforcing steel, connected as a cathode, and an external, distributed electrode, connected as an anode. Current flow at a rate of at least 0.1 ampere per square meter of surface area of the embedded reinforcement is continued for a time sufficient to provide a total charge of at least about 100, but not substantially more than 2000, ampere-hours per square meter of surface area of the embedded reinforcement. This results in steel with a clean surface, surrounded by concrete which is chloride free and highly alkaline. After discontinuance of the electrochemical treatment, the embedded steel slowly passivates by forming a protective surface oxide. The process is significantly more economical than known procedures, yet is reliably effective.

Abstract: A cathodic protection system for protecting buried conducting structures, subject to corrosion such as well casings, pipe lines and the like, utilizes a plurality of pulsed D.C. current sources with the negative output terminal of each source connected to a separate structure and the positive output terminal of the sources connected to a common anode located near the structures. A control circuit synchronizes the operation of the several D.C. sources and sets the frequency and width of the output pulses. The amplitude of the output pulses from each D.C. source may be separately adjusted.

Abstract: A system for inhibiting marine organism growth on underwater surfaces provides an electric current generator which causes an electric current to flow proximate the underwater surface. A source of power, such as a battery, provides electrical power to the electric current generator. The flow of current passes from the underwater surface through water surrounding the surface or in contact with the surface, and a point of ground potential. The point of ground potential can be a marine propulsion system attached to a boat on which the underwater surface is contained.

Abstract: An electrochemical stain prevention apparatus of a submerged structure comprising a submerged structure of which at least the stain prevention surface is formed of a conductive film that does not generate chlorine even by applying a potential of 5 V vs. SCE or less, a counter electrode located so as not to contact with the submerged structure, and a power supply unit for passing a direct current through the submerged structure having the conductive film formed thereon and the counter electrode. Aquatic organisms adhered to the surface of the conductive film can effectively be controlled by applying a potential of from 0.1 to 5 V vs. SCE to the submerged structure of such a stain prevention apparatus without generating chlorine. A potential applied to the conductive film of the submerged structure can be controlled with good accuracy by disposing a reference electrode between the submerged structure and the counter electrode.

Abstract: An apparatus for prevention of corrosion in metal objects uses a pad having a conductive facing, a dielectric substrate and an adhesive, attached to a metal body being protected from corrosion. The metal body and the negative terminal of a source of DC voltage (battery) are grounded. The positive terminal of the source of DC voltage is connected to electronic circuitry that imparts pulses of low voltage DC to the conductive facing of the pad. These pulses of electrical current inhibit the oxidation of the metal object by providing a source of electrons to the oxidizing chemicals in contact with the metal. The electronic circuitry includes a reverse voltage protector to prevent the application of reverse source voltage. The circuitry also includes a power conditioner to supply a constant DC voltage to a microprocessor. The microprocessor generates pulses of DC signals that are amplified by a pulse amplifier and imparted to the conductive facing of the pad.

Abstract: In an electrically corrosion-proofing process in which the polarity of a metal member having a coating film is set at negative, the duration of setting the polarity of the metal member immersed in an aqueous solution of NaCl at negative is made discontinuous, and a positive-set duration in which the polarity of the metal member is set at positive, is interposed between a proceeding negative-set duration and a succeeding negative-set duration. The switching-over of the polarity is carried out by a polarity switch-over relay between the metal member and a DC power source. In the negative-set duration, the treatment for corrosion-proofing of the metal member is carried out, but the peeling-off of the coating film from a starting point provided by a damaged portion is produced. In the positive-set duration, an electrolytic product is produced in an exposed portion of the metal member, and the peeling-off of the coating film in the next negative-set duration is prevented by the electrolytic product.

Abstract: The invention concerns a method for inhibition of growth of organisms on faces of constructions (11) submerged in a liquid. In themethod, an electrically conductive structure (11) to be protected is connected as the cathode of a source (14) of direct current, or an electrically non-conductive structure (111) to be protected is first coated with an electrically conductive material (111a) and connected as the cathode of a source of direct current (14), respectively, and, as the anode (12), an anode is used that has been isolated from the structure (11) to be protected or that is placed separate from said structure, which anode is connected as the anode of the source (14) of direct current.

Abstract: A cathodic protection system for protecting buried conducting structures, subject to corrosion such as well casings, pipe lines and the like, utilizes a plurality of pulsed D.C. current sources with the negative output terminal of each source connected to a separate structure and the positive output terminal of the sources connected to a common anode located near the structures. A control circuit synchronizes the operation of the several D.C. sources and sets the frequency and width of the output pulses. The amplitude of the output pulses from each D.C. source may be separately adjusted.