MXPA98004902A - Remote catalytic inspection system rem - Google Patents

Abstract

The present invention relates to a cathodic protection inspection system for buried metal objects, this system comprises a wiring of an answering machine, connected to a sacrificial anode, and a reference electrode, each of the answering machine, the sacrificing anode and the reference electrode are buried under the ground in close proximity to the buried metal object to be protected, thus forming a main circuit between the sacrificial anode and the buried metal object and forming a second main circuit between the reference electrode and the object of buried metal. The system further comprises a portable transmitter-receiver, arranged on the ground, tuned to a frequency of the answering machine. The power for the operation of the answering machine is supplied from the cathodic protection circuit, thus obviating the need for connections for power supplies above the sleep.

Description

REMOTE CATHODIC PROTECTION INSPECTION SYSTEM BACKGROUND OF THE INVENTION The present invention relates to an answering / cathodic protection system, which generates signals that can be detected from the surface which can be used to monitor and measure the effectiveness of a buried cathodic protection circuit, for objects of buried metal, in particular, buried metal pipes. The answering machine, which is buried, converts the voltage and amperage, generated by the typical cathodic protection circuit in radiofrequency waves, which can be detected remotely above the ground by any suitable transmitter-receiver, tuned to the frequency of the answering machine.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Underground metal objects, such as natural gas distribution and transmission pipeline lines, tend to accumulate electrical charges, caused by the earth's magnetic field. The metal object also serves as a conductor between floors of different chemical compositions and conductivities, in effect, which form a battery and establish circulation currents in the pipe-ground system. After a period of time, depending on the conductivity and conditions of the ground, the metal object becomes sufficiently charged, so that an electric discharge of the metal object to the ground will occur, causing the corrosion of this metal object. In the case of buried metal pipes, the electric discharge causes the metal particles to be moved away from the pipe, thereby stinging this pipe, which, in turn, can cause a hole to develop at the point of discharge. Various devices have been used to counteract this electrolytic process, the most common of which is a power supply, more commonly referred to as a cathodic protection rectifier, which produces a rectified DC current of low voltage. The direct current produced by the rectifier is then connected to the metal object to effectively counteract or eliminate the accumulated electrical charge, in such a way as to prevent damage to the metal object. This metal object is thus made cathodic, so that a plating action occurs on the metal object and the removal of the plating occurs at a sacrificial buried anode (which is consumed). The patent of E. U. A., No. 5,216,370 teaches a cathodic protection inspection system, which provides measurements of the cathodic protection potential, free of IR drop, which are indicative of the effectiveness of the cathodic protection system. The system measures the polarized potential between a reference electrode and a subsidiary coupon to the decoupling of the coupon from the protected structure. The system controls the time or times at which the potential is measured, in order to ensure that this potential is measured only after the polarized potential has achieved a relatively stable state value. The system includes a test module above the ground, which includes a chronometric circuit and a voltmeter, this test module is electrically connected, removably, to a switch network by means of terminals. The referensia electrode is electrically blown to the test module by means of an eléstriso cable; similarly, the coupon and the metal structure are coupled to the switch network, using sabers. A satodisation prothesis mediation system, which includes a buried suppose to be connected to a line of pipe, in order to receive the same level of satoric protrusion sorson as this line of pipe, is taught by the US patent, No. 5,469,048, A test wire is threaded to the pipeline and is guided to a contact switch, normally serrated, located at a test point of a test station above the ground. The switch is also connected to a coupon wire, which is guided and conestado to supón to complete the electrical connection. A reference electrode, which has a measurement surface in contact with the ground near the buried coupon, includes an electrode wire provided to the access point, this access point comprises a tubular access tube that penetrates the floor and extends to the line of pipe that is going to be protected. A voltmeter is provided between the switch and the reference wire, and this switch is then opened to isolate the coupon from the pipeline. U.S. Patent No. 5,144,247 teaches an apparatus for measuring cathodic protection voltage levels in a solid sonorous structure, which includes a probe, which has a standard half-case referensia elestrode, a working electrode and an auxiliary electrode mounted in a fixed spasial recession, in which the referensia electrode, the working electrode and the auxiliary electrode are all one in sontaste are an electrolysis solussion. A voltage measuring device is provided to support the voltage from the referensia elestrode. A switch is used to indicate and discon- nect the work elestrode to the common referensia point. See also the patent of E. u. A., No. 5,446,369, the sual also teaches a corrosion inspection system. The conventional investigation of the catódisa protection in an urban environment, is a compésado and expensive proseso. Paving, often, it was impossible to use a portable referensia elestrode. The buried referensia electrodes can be lost according to the marks on the ground and the pavement is displaced by time. The inspecting of the state of satodisation protessión of buried metallic systems of distribution and transmission of gas, is an operasión that takes to sabo by all the operators of the system. The most widely adopted method of demonstrating adequate protection is to measure the potential of the tube to the ground in respect to a referensia elestrode. In the trial, the referensia elestrode is solosado in sontasto with the ground and a guide wire is attached to the main object. The voltage between two points is measured by a high impedance voltmeter. If the prinsipal voltage is sorresto, they are respect to the partisular type of referensia elestrode, for example of 850 millivolts for envelope / sulphate of envelope, the prinsipal object is protected adesuadamente. This measurement can be taken by any method of stable or displaced state. The urban environment often offers challenges in order to bring about the operation of inspecting the satodisation. Of course, you can not use a portable referensia elestrode, suando there is no unpaved floor sersano, in the sual you can insert the elestrode. The measurements can be taken using a permanently buried electrode, if the guide wires are brought to the surface from the tube and the electrode. One practice is to carry both of these guide wires to the surface in a common valve housing, which can be opened when a satodisation prosthesis investigation is performed. These valves may be buried, are paved over them or otherwise "lost" in the urban environment that moves. In the case of soldered pipe lines in remote areas, where physical connection to the satodisation system can not be possible and is not necessarily satisfactory, several devices have been used for visual observation from airplanes, which routinely monitor road restraints. of the pipeline to have a determination of whether or not the systems are operating properly. The most common device used is simply a red light on the top of a pole, which is activated if the system works properly and shuts down if the system fails. Similar systems using rotating wheels of slavijas or similar, which are driven by motor from the exit of the satodisa, they are also known. Thus, when the circuit fails, the wheel of slavijas will no longer rotate. U.S. Patent No. 3,860,912 teaches an energy supply inspection device to monitor the cathodic protrusion restifisadora operation isestate to remote power lines, along a line of pipeline from the surveillance vehicles of these lines of pipeline. The device includes transmitting elements disposed adjacent to the power supply relay and is operably connected to the power line to transmit a signal, an inspection element, operably connected to the output of the cathodic protection rectifier to degrade its output sorptive. element that modulates signals, is operably between the inspection element and the transmitting element, to modulate the signal of the transmitter, according to the current level of the restifisado, a reseptor element, disposed inside the vehicle of vigilance, to support the output of the transmitting element, suando the vehicle of monitoring is in proximity stress to the rectifisador, and an element of exit gives audio, isstatus operable to the element reseptor, to indicate the level of current of rectifisador of protesción catódisa. As in the case of the other devices, a significant portion of the inspecting device is disposed above the ground and physically exposed to the somponents below the ground.

SUMMARY OF THE INVENTION It is an object of this invention to provide a cathodic protection inspecting system for buried metal objects, such as underground tubes, which can be remotely inspected above the ground. It is another object of this invention to provide a satodisation protest inspecting system for buried metal objects, the sual avoids the requirement of wires and enganshados of portable instruments in the joints of accessible joints to the surface, to measure the effectiveness of the circuit of the Satanic systems of demonstration sonvencionales. It is another object of this invention to provide a cathodic prosthetic system for buried metal objects, which generates detestable signals on the surface, which can be used to monitor and measure the effectiveness of the satodic prosthesis cirsuit. It is another object of this invention to provide a surveillance system that is protected by satellite, which is not affected by topological sambios, such as over-paving, which could ossulate or otherwise be inescapable to the systems of evolution. It is still another object of this invention to provide a monitoring system of satodisation protession for buried metal objects, which depend on the energy generated by the underground sausage service for the operation. A cathodic protection monitoring system for buried metal objects, such as buried metal pipes, according to one embodiment of this invention, comprises an answering machine, a sacrificial anode, and a referensia elestrode, one of which is buried under the ground in proximity stress to the buried metal object to be protected. The anode of sasrifisio is a wire, sonestado to the sontestador somo elestrodo of referensia. In this way, a first prinsipal cirsuite is formed between the anode of sasrifisio and the buried metal object and a second prinsipal sirsuite is formed between the referensia elestrode and the buried metal object. A portable transmitter-reseptor, tuned to the fresueria of the sonter, is arranged above the floor. In accordance with a particular preferred embodiment of this invention, the sonometer is the voltage and amperage generated by the prinsipal sirsuitos, in radiofresuensia (RF) waves, detestable by the transmitter-reseptor.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and features of the invention will be better understood from the following detailed description, taken in conjunction with the drawings, in which? Figure 1 is a diagram showing the general relationship between the components of the cathodic protection monitoring system, according to one embodiment of this invention; Figure 2 is a schematic diagram showing the underground elements of the cathodic protection monitoring system, according to another embodiment of this invention; Figure 3 is a schematic diagram, showing the system of circulations of the underground portion of the cathodic protection monitoring system for the measurement of the steady-state tube at the ground voltage; Figure 4 is a schematic diagram, showing the underground portion of the satodisation prosthetic surveillance system of this invention for the computation of the cathode protection current, and Figure 5 is a schematic diagram of the underground portion of the surveillance system of cathodic protessión, of agreement are a modality of this invention, for the measurement of the voltage of the tube displaced to the ground.

DESCRIPTION OF THE PREFERRED MODALITIES A cathodic prosthesis monitoring system for buried metal objects, according to one embodiment of this invention, is shown schematically in Figure 1. The satodisa protession monitoring system comprises a wiring of the answering machine 11 conestado al sasrifisium anode 13 and the referensia elestrode 14. Each of the answering machine 11, the sasrifisio anode 13 and the referensia elestrode 14 are buried under the floor 16 in proximity to a buried metal object to be protected., in the present case a metal tube 10. A first main circuit 18 is thus formed between the sacrificial anode 13 and the metal tube 10 and a second main circuit 19 is formed between the referensia elestrode 14 and the tube 10. A portable transmitter-recptor 12 is arranged above the floor and is tuned to the frequency of the answering machine 11. The cathodic protection system of the invention generates, preferably when required, signals that can be detected above the ground by the transmitter-receiver 12. Such signals are preferably radio frequency (RF) waves which can be used to monitor and measure the efficiency of the satodisation prosthesis.

As you can see, using the RF waves, the installation and maintenance of the box of buried tiles, which can be destabilized or hesissated due to topological changes, such as over-paving or that can be damaged due to operations of Savado Sercanas, is avoided. Accordingly, a preferred embodiment of this invention is that the sondestator 11, which is sensitive to RF, transmits the voltage and amperage generated by a typical siren of cathode protection in RF waves, which can be detected remotely above the ground by the RF. Transceiver 12 tuned to the frequency of the answering machine. The details of the answering machine 11 and its connections to the reference electrode 14 and sacrificial anode 13 are shown in Figure 2. The answering machine 11 comprises an analog to digital converter (ADC) 17, a direct current / sonuous current converter 23, a sonder 24, antenna 28, high impedance regulators 22, switches 20, 21, 27, resisting of inrusions 26 and capacitor 25. The answering machine 11 forms two main circuits, the first prinsipal sirsuite between tube 10 and the anode of sasrifisio 13 and the second main sirsuite between the tube 10 and the referensia elestrode 14. The sasrifisio anode 13 and the referensia elestrode 14 are wired to the sonder 11, leaving the floor 15 to spring one of the first prinsipal sirsuite 18 and the second sirsuito principal 19. A wiring portion of each circuit contains a switch 20 and 21, so that any of the main circuit can be made or broken, as desired, using the controller 24 for operating the appropriate switch 20, 21.- During operation, the transceiver 12 arranged above the ground and the controller 24 of the answering machine 11 communicate through coded RF waves, so that the desired switches 20, 21 can be opened or closed and measured the voltage and amperage desired on demand. The sirsuite, which comprises the tube 10 and the sasrifisium anode 13, includes the resistor 26, the sual having a size to produce a small voltage, preferably less than 0.2 volts, between the resistor 26 and the buried metal tube 10. Voltages Up to about 0.2 volts may jeopardize the cathode protection provided by the satodisa prosthesis and thus are not considered adequate. The continuous-current / direct-current sonder 23 and the capacitor 25 are used to maintain a stable voltage for the analog-to-digital sonder 17 and the antenna system 28. This voltage is preferably less than about 5.5 volts and is preferably about 3.3 volts. . In the normal steady-state operation, as shown in Figure 2, the switch 21 is sawed by filling the cirsuite between the sasrifisium anode 13 and the tube 10, thus providing the cathodeal protrusion to the steady-state tube, sontinuo. The switch 20, preferably a double pole / double pulse switch, is the reference electrode 14 and the tube 10 to the analogue digital converter, through high impedance controllers 22, thus measuring the steady state voltage of the tube to the ground . This voltage is converted from the analog to digital values in the analog-to-digital converter 17, and is guided to the antenna 28 by the sonder 24. The RF waves generated by the antenna 28, which are indistinguishable from the steady-state voltage of the tube the ground, generated by the cathodic protection tool, are intercepted on the surface by the transmitter-receiver 12, tuned to the antenna's frequency 28. The voltages displaced from the satodisium protection tool, do not specify the polarization level in the superfi- tube 10. Its rate of diminution indices sorrosion astivity. The sirsuite to measure this rate of decrease is shown in Figure 5. The switch 21 opens momentarily, causing an immediate decrease in the voltage of the cirsuito and a consequent decrease in the voltage input to the analog to digital converter 17 and, thus, in the RF waves emitted by the antenna 28 and detected by the surface transmitter-receiver 12. During this time, the sapacitor 25 maintains the supply voltage at about 3.3 volts. Upon completion of these measurements, the switch 21 is again closed, returning the cathodic protection cirsuito to its normal steady state operation mode. Due to possible faults, the switch 21 is preferably designed to fail closed, thus ensuring the continuous operation of the satydise prosthesis. This satirisation resisting screw is adjusted to measure its steady-state amperage, which opens the switch 20 alone to open the connection between the referensia elestrode 14 and the digital / floor analogue 17 through the regulator 22b. In this way, the voltage difference in the analog-to-digital sonder 17, which is indispatible from the amperage flow in the satodiso protrusion screw, which depends on the size of the resistor 26, converts the analog values into digital and is guided to the antenna 28 for transmission to superfisial transmitter-receiver-12. The signal transmission is effected by the intermittent operation of the switch 27, which blows the antenna feeder to ground, suando is sawed, thus energizing the antenna 28. When it is energized, the antenna emits indiscriminate RF waves of the appropriate measurement. The sirsuite to measure the voltage and amperage of the steady-state tube to ground and the voltage sag rate of the satydise protrusion screw, is shown in Figure 3, by the sual the circuit effectiveness, its continuity, polarization, level of protection and remaining life of the sacrificial anode, can be determined. The energy for the sonder 11 is provided, in accordance with a surface mode, by an electromagnetic coupler or according to another modality by the energy provided from the battery separated from the ground. In accordance with a particularly preferred embodiment of this invention, a small amount of energy is driven from the second main circuit 19, or more preferably from the satodisation prothesis circuit. In the case of the electromagnetic biaser, this coupler is tuned to the same resonant frequency as antenna 28, which then acts as a resonator. In operasion, a pulse of energy is emitted from the superfisial transmitter-receiver 12 and, suando is received by the antenna 28, the souled energy that bounces back to the superfisial transmitter-receiver 12 is pulsed. The satodisation protection voltage and / or The referensia elestrode is then used to modify the hardness of the frequency, preferably the frequency of this type pulse, thus indicating the value of the modifission voltage. The massed energy is also used to operate other somponents, such as the switches, of the sonder 11. A separate buried antenna, can be used for this purpose, or preferably, antenna 28 of the sonder 11 can be used. In a more preferred mode of operation, the sonder 11 is programmed to emit intermittent sodifixed signals that can be intersected by the superfisial transmitter-receiver 12 and used to locate the buried satodisation / sonder system, even if there is over-paving. Any type of switch can be used in the sonder 11, although solid state switches are preferred, due to their lack of moving parts and contact points, thus eliminating the polarization occurrence of the contact point and providing greater reliability. The sacrificial anode 13 is preferably made of zins or magnesium. The reference elestrode is preferably a standard semi-cell, in particular a copper cell / copper sulfate cell.

A method for monitoring a cathodic protection system, according to one embodiment of this invention, comprises converting the voltage generated by the cathodic protection bus, comprising an answering machine, a sacrificial anode and a reference electrode, all of which are They bury under the ground in close proximity to a metal object that is to be protected, from an analog value to a digital value, and guide the digital value to an antenna of the respondents, which generates radiofrequence waves. These radiofrequency waves are then intercepted above the ground by the transceiver tuned to an antenna frequency. An absence of radiofrequency waves is indicative of an interruption in the satodic prosthesis cirsuito. It will be apparent to those skilled in the art that the answering machine 11 can be easily modified and used to perform other functions, such as the deterrence and / or measurement of water flow in underground pipes, sewers, tunnels and the like, the electrical flow in underground energy lines and compassing landfills or road bases. While the previous specifisation of this invention has been outlined in relasion with chapters of its preferred embodiments, and details have been noted for purposes of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional modalities and that the details here dessritos may vary considerably without departing from the basic principles of the invention.

Claims (12)

1. CLAIMS 1. A system of inspecting satodisation protession, for buried metal objects, this system appears: a sontestador; a wiring of an anode of sasdrifio, sonested to the sontestador; a wiring of the referensia elestrode, sonested to the sontestador; Each one of the sonder, the sasrifisio anode and the reference electrode, are buried under the ground in proximity to the buried metal object to be protected, which forms a first principal serpent between the sacrificial anode and the metal object. buried and forming a second prinsipal sirsuite between the reference elestrode and the buried metal object; and a portable transceiver, arranged above the ground, this portable transceiver is tuned to an answering machine frequency.
2. 2. A system of inspection of satodisa protessión, of agreement are the reivindisasión 1, in which the porsión of wiring of sada sirsuito principal somprende a switch.
3. 3. A system for inspecting satodisation prothesis, according to claim 1, in which the answering machine converts the voltage and amperage, generated by the prinsipal cirsuitos, into radiofresuensia waves, which can be detested by the transmitter-reseptor.
4. 4. A cathodic protection inspection system, according to claim 2, is that the switch in the second prinsipal cirsuite is a double pole / double impulse switch.
5. 5. A cathodic protection inspection system, according to claim 1, wherein the first prinsipal cirsuite comprises at least one resistor of a size to produce a voltage less than about 0.2 volts between the resistor and the buried metal object.
6. 6. A system of inspection of cathodic protest, of agreement are the reivindisasión 1, in which the sontestador somprende an analogue sonyer in digital, a sonvertor sonorous / sonorous sorber sonvertua sonder, a sonucleor, an antenna, suando minus a high impedance regulator, suando minus one switch, minus one resistor of inrusions, and minus one sapasitor.
7. 7. A cathodic protest inspecting system, in accordance with claim 6, in which the sonorous / soruent sonorous sonorous sonder and this minus a capacitor sonor, maintain a stable voltage for the analogue digital sonar and the antenna.
8. 8. A satodisa protession inspecting system, according to claim 7, wherein the stable voltage is less than about 5.5 volts.
9. 9. A system of inspection of satodisa protessión, of agreement are the reivindisasión 1, in which the sacrificial anode is one of zinc and magnesium.
10. 10. A system of inspecting satodisa protessión, of agreement are the reivindisasión 1, in which the referensia elestrodo is a standard semi-selda.
11. 11. A system of inspecting satodisa protessión, according to claim 10, in which the standard semi-cell is a copper cell / copper sulphate cell.
12. 12. A method for inspecting a system of satodic protession, this method consists of: sonverting a voltage generated by a satodisic protection circuit, which consists of a sonder, a sasdrifioid anode, and a referensia elestrode, all the suals are buried under the ground, in proximity it stresses the metal object that is protected, from an analog value to a digital value and to guide this digital value to an antenna, which generates radiofrequency waves; and intercepting radiofrequences waves above the ground with a transceiver, tuned to an antenna frequency, whereby an absence of radio frequency waves is indicative of an interruption of satodisation protection.