CN102912354A - Cathode protection system for underground pipeline system - Google Patents

Abstract

Translated fromChinese

地下管道系统用阴极保护系统，其构成如下：馈电电缆（401）、馈电连接头（402）、牺牲阳极（7）；其中：馈电电缆（401）的下端通过馈电连接头（402）与地下管道（1）外壁固定连接且构成电连接，牺牲阳极（7）固定连接在馈电电缆（401）的另一端；防水套管（5）放置在外护管（2）内，其前端固定布置有馈电连接头（402），馈电连接头（402）与地下管道（1）二者之间焊接固定；牺牲阳极（7）具体通过馈电装置（4）与地下管道（1）形成电连接，并最终构成地下管道阴极保护系统。本发明是一个系统工程，涉及的内容较多；技术成熟度较高，具有可预期的极为巨大的经济价值和社会价值。

The cathodic protection system for underground pipeline system is composed as follows: feeder cable (401), feeder connector (402), sacrificial anode (7); wherein: the lower end of feeder cable (401) passes through the feeder connector (402 ) is fixedly connected with the outer wall of the underground pipeline (1) and forms an electrical connection, and the sacrificial anode (7) is fixedly connected to the other end of the feeder cable (401); the waterproof casing (5) is placed in the outer protective tube (2), and its front end The feeder connector (402) is fixedly arranged, and the feeder connector (402) and the underground pipeline (1) are welded and fixed; the sacrificial anode (7) specifically passes through the feeder (4) and the underground pipeline (1) Form electrical connection, and finally constitute underground pipeline cathodic protection system. The present invention is a system engineering involving many contents; the technology has a high degree of maturity, and has predictably huge economic value and social value.

Description

The underground piping system cathodic protection system

Technical field

The present invention relates to underground pipeline guard technology field science, a kind of underground piping system cathodic protection system is provided especially.

Background technology

In the prior art, adopting heavy caliber steel water-transmission line to have safety, reliably reach short advantage of construction period, is to compare common method in the present water delivery engineering.This technique mainly is to carry out the pipeline jacking by operation between working shaft to bury underground, ground excavation is not carried out on other pipeline approach ground except working shaft, adopt traditional corrosion prevention technique to be difficult to thoroughly solve push pipe pipeline endurance issues, bring a new difficult problem for durability Design and the construction technology of pipeline.From present built push pipe pipeline situation, this mainly exists corrosion protection coating performance and this construction technology matching problem, weld repaired mouth matching problem, relay well coating protection problem, and cathodic Protection Design and construction technology problem etc.Application about heavy caliber steel push pipe pipeline weather resistance has become the technical barrier that needs to be resolved hurrily with more worth.

Because in big and medium-sized cities enlarging or the newly-built water-transmission line engineering, usually bury underground in the soil of pipeline or built on the ground urban infrastructure or buildings arranged, adopt open excavation to bury heavy-caliber pipeline underground and can destroy these built urban infrastructures, as: road surface, green belt, structures etc., this brings difficulty to burying pipeline construction underground, construction cost is significantly improved, and city resident's orthobiosis is brought impact.Non-excavation is buried the progress of pipeline technology underground and is improved and makes the people see the hope of dealing with problems in recent years, the method that present non-open type is buried pipeline underground mainly contains shielding method, directional drilling method, jacking, wherein jacking pipe construction process is fit to heavy caliber steel pipeline construction, comprehensive cost is low, operating efficiency is high, and is minimum on urban facilities and resident living impact.

If the land-based area water-transmission line is buried darker, take 3.6 meters push pipe pipelines of diameter as example, the depth of burying points out in the graduate report of survey of Shanghai geotechnology survey and design all more than 10 meters, and when depth of soil during greater than 10 meters, soil resistivity is mostly less than 10 Ω m.If ground water table higher (for example: there are rivers and canals many places on the way) estimates that this type of edatope has stronger corrosion failure to the steel pipeline.In addition, also should especially pay close attention to some distinguishingly corrosion of depot siding, for example: have magnetic suspension train to pass through part, be provided with the AC Substation part.The galvanic corrosion that these places also all may bring larger stray current to cause to pipeline.

Attachment weld and adopt the corrosion prevention of the weld of relay well technology pushing pipe also to need especially to pay close attention between pipeline section in the jacking construction process.

In a word, the etching problem of underground construction steel push pipe can not be ignored, and for ensureing this project weather resistance, must take corresponding corrosion prevention measure to the steel push pipe.And, if the steel push pipe is buried underground deeply, must cause maintenance difficult, the more impossible pipeline of midway changing, so the corrosion prevention measure of this class steel push pipe must be reliable, namely life requirement is high.But owing to this pipeline distance, bury underground dark and require non-excavating construction, its corrosion prevention faces many problem demanding prompt solutions.

1, in the prior art, the brief introduction of buried steel push pipe corrosion protection method is as follows: the corrosion of steel push pipe in soil is because certain parts of steel is in the anode status in itself and the formed battery of edatope, current potential is lower, causes corrosion because electronics runs off, and sees Figure 18.

In order to suppress corrosion, people adopt following several means of defence:

1) reserves corrosion allowance: the large-diameter steel pipe that adopts heavy wall, rely on the corrosion allowance of steel self to reach requirement life, this method needs expensive iron and steel resource, and manufacturing and installation costs are higher, long construction period, need strongly professional tubulation equipment, also there are the problems of terms of mechanics in this for bigbore steel push pipe.In addition, the destruction that the steel push pipe that only leaves corrosion allowance may produce Unpredictability owing to local corrosion and stress corrosion at the soil corrosion environment.Simultaneously, China also seldom possesses the heavy caliber of production in enormous quantities in enormous quantities hyper-thick pipe steel pipe ability at present.

2) corrosion-resisting alloy steel: the material scholar has developed multiple corrosion resistant low-carbon alloy steel and stainless steel over nearly 50 years, comprise 10CrMoAl, 304,316L and 00Cr26Ni7Mo2Ti etc., although its erosion rate is low more than 2 times than plain carbon stool, but weldprocedure is complicated, easily produce serious spot corrosion, galvanic corrosion, stress corrosion etc. in weld and heat affected zone, thereby reduced the security of the structural entity of using, and cost is also higher.

3) supercoat or organic protection lining are anticorrosion: since the mid-eighteenth century, coal tar, the anti-corrosion method of oleum lini as metal were adopted in Europe; protective coating obtains flourish; become the most widely anti-corrosion measure of metallic substance, corrosion protecting coating has formed organic coating, sand-cement slurry, enamel paint and metal cladding 4 large systems.The coating antiseptic etching method on the whole, construction is simple, is applicable to all corrosive environments, but its need to possess environmental sound, intact characteristics in whole military service process as protective devices independently.This need to and follow-up in servicely obvious breakage not occur in prefabricated, installation, carrying, otherwise can aggravate the corrosion of regional area.Lining anticorrosion mainly with materials such as rubber, glass reinforced plastic, polyethylene as lining, carry out the method for special more protection in the part.

4) cathode protecting process: first cast iron is connected to since the Dai Wei of Britain in 1836 on the brass of hull it is carried out galvanic protection since, the method is extensively promoted, and is indispensable especially in the protection of buried pipeline.The principle of galvanic protection is to take artificial means that the steel current potential is reduced, thereby suppresses the corrosion of steel.This point can find out that from the pH-Electric Potential Graph of steel when the current potential of steel was lower than a certain value, steel were in not etch state, see Figure 23.Especially the current potential at steel be lower than-0.85V(is with respect to saturated copper/copper sulfate reference electrode, is called for short CSE) after, therefore-0.85V/CSE also becomes the current potential criterion of steel galvanic protection, extensively adopted in cathodic protection engineering the corrosion of steel can be ignored.

Reaching the method that such purpose takes is that electronics is flowed from the outside towards steel, thereby reduces the corrosion speed of steel, shown in Figure 24,25.

Different according to the means that reduce the steel construction current potential, the galvanic protection means are divided into impressed current (Figure 24) and two kinds of methods of sacrificial anode (Figure 25), and both contrasts see the followingform 1.

The relative merits of two kinds of galvanic protection modes of table 1

As can be seen from Table 1, the sacrificial anode method does not need additional power source, and stability is high, substantially need not keep in repair in design period, but the initial stage has high input.Impressed current method the method is to utilize rectifier that galvanic current is provided, and provides required protective current by supplementary anode to underwater steel construction, thereby reaches the purpose of protection.External source need to be arranged, and equipment must be managed, safeguard that initial investment is less, but in case extraneous power supply disconnects, then steel construction will lose protection.From investigation result, under ocean environment, the atomospheric corrosion degree is regional much serious than other, safeguards that the equipment difficulty of impressed current method needs is very large.In many engineerings, although adopted strict preventive means, the equipment such as potentiostat constantly go wrong in application process, have seriously undermined the effect of galvanic protection.Simultaneously, impressed current equipment claimed professional safeguards incessantly for a long time, has expended a large amount of manpowers.Therefore, the sacrificial anode method is adopted in the in recent years galvanic protection of the facility of most heavy constructions.The husky gigantic project of green grass, complex structure, impressed current method will be very complicated engineerings, poor reliability, and can be to relevant electric power facility, such as generation severe jammings such as telecommunication cables.Therefore, will tentatively to select the sacrificial anode method be this galvanic protection research contents in this research.

But, if only carry out independently galvanic protection with sacrificial anode, consumable anode enormous amount then, high cost, in addition can be because of the shielding effect between pipeline itself and the pipeline so that the subregion can not get adequately protecting.

5) high-performance coating adds galvanic protection and unites protection:

In order to remedy the shortcoming of cathodic protection, begun in recent decades to adopt galvanic protection to add coating and united the method for protection buried pipeline is protected.In the past, coating adopted the protective system of general barrier propterty such as epoxide coal bituminous, low solid part protective system etc. to carry out the steel pipe protection mostly.This class corrosion protection coating barrier propterty is relatively poor, shows two aspects of mechanical property and anti-permeability performance, generally only has 10 year life-span under edatope.In the push pipe process, the impact that the effect of coating and clay, silt, microlith produces wearing and tearing, scratches, the coating damage rate is also very high; Along with the development of coating technology, coated material is under ocean environment, and particularly the long-effective protection validity under the galvanic protection condition is significantly improved, as the protection latter stage coating protection efficient can be more than 80%.This anti-medium osmosis, wet adhesion and antikathode separability (compatibility performance of reflection and galvanic protection coupling) that mainly has benefited from coating itself has had significantly and has improved, and directly is reflected in and implements can guarantee coating protection performance, consistency and work-ing life after the galvanic protection.

In sum, heavy caliber buried steel push pipe pipeline should adopt " high-performance coating+sacrificial anode " Combined Protection scheme.But for the steel pipeline of heavy caliber, buried dark and so long distance, be that coating or galvanic protection all face and need a urgent difficult problem that solves, the below describes in detail.

2, the problem that faces of steel push pipe corrosion prevention

Up to the present, the distance of completed individual event pipe-jacking project is all shorter, generally only has hundreds of rice, is mainly used in railroad crossing, highway, river or structures.Along with the progress of construction by pipeline jacking method technology, single jacking distance develops into 2000 meters of single jackings by hundreds of rice, and bore is from 1000 millimeters to 4000 millimeters, and tubing also has the steel pipe push pipe of China's original creation except adopting steel concrete pipe, matrix material.Because such engineering construction belongs to emerging project, does not still have complete reliable process for corrosion control in order to guarantee the weather resistance of push pipe.Since application heavy caliber, long distance steel push pipe are the main selection schemes that solves the enlargement of cities water supply problem, and etching problem is the technical barrier that this scheme of restriction is used, so must study as early as possible the corrosion control technology that matches with it, and set up corresponding design and constructional method and planning standard.American-Europeanly in recent years wait that developed country's infrastructural project specification is less, quantity is relatively less, particularly the steel pipe jacking construction technique is abroad seldom used, without ripe supporting pipe-jacking technology and the reference of design and construction standard.For satisfying the needs of at present a large amount of engineerings, the corrosion control new technology of independent research large-diameter steel push pipe is badly in need of in China.This technical security, reliability requirement height, because the heavy caliber pipe-jacking pipeline is buried usually darker, it is extremely difficult that pipeline corrodes repairing outward.If construction and run duration are because corrosion brings safety problem to bring major disaster to the high-density Urban areas.In addition; the embodiment of this technology is different from traditional method; for example; can't adopt and when the excavation buried pipeline, follow the galvanic protection that pipeline laying is welded repaired mouth and buried sacrificial anode underground; more do not allow to adopt novel welding patch technology and cathodic protection system to satisfy the weather resistance requirement of shelter of steel push pipe burying sacrificial anode underground from earth's surface opening excavation.

Solve steel push pipe pipeline weather resistance key and be " coating+sacrificial anode " Combined Protection scheme-take the long-acting high-performance coating system protection of high-quality as main of adopting; sacrificial anode is auxiliary associating Project for Corrosion Protection; but because the outside surface of pipeline bears stratum soil sandstone in the jacking pipe construction process implementation process compressing power and strong frictional force; therefore the corrosion protection coating of outer surface of steel tube is except having traditional antiseptic property; also should have the characteristic that the sandstone of anti-soil scratches and weares and teares; otherwise with the integrity of tamper protection coating, the barrier propterty of coating is descended even inefficacy in the jacking construction process.Simultaneously, because cathode protection technology and the protective coating system that does not have ripe non-excavating construction is complementary, cause the difficult realization of integrity of safeguard system, therefore need to carry out the research of coating and two aspects of galvanic protection.

(1) High performance protective coating technical study: the heavy caliber pipe-jacking pipeline is buried darker, repair during one's term of military service very difficult with digging mode, or even impossible, must adopt the high performance and long service life protective coating, avoid pipeline protective coating in the jacking construction process to damage inefficacy because of construction, guarantee during one's term of military service effective weather resistance of coating protection.At present buried pipeline protective coating life, all about 30 years, the principal element that affect coating life was the sticking power of coating, scratch resistance and anti-permeability performance, and need further improve these salient featuress, make coating life bring up to 50 years.

Wherein affect the critical performance parameters of weather resistance:

1) sticking power: by 24 hours/95 ℃/1 grade of standard bring up to 15 days/95 ℃/1 grade;

2) wear resistance: the 100mg by standard brings up to 30mg (1 ㎏, 1000rpm);

3) anti-water permeability: by 15 days/60 ℃/3% bring up to 150 days/60 ℃/2.0%.

Each pipe joint pipeline must weld in active well in the jacking construction, this is the technological process of necessity of this construction technology, needing after welding is finished that corrosion prevention is carried out at this position processes, if can carry out corrosion prevention to this position fast and effectively at the construction field (site), need to have SLF shorten in 60 minutes in original 4 hours completely without the solvent bi-component epoxy coating high strength ambient cure time.The coating performance of this repaired mouth reaches These parameters equally, guarantees the consistence of whole pipeline coating antiseptic performance.

The large tube coupling weld seam of relay well is the interior Welding that carries out underground; this position is the weak link of whole pipeline weather resistance protection; this process implementing should be as far as possible little the destruction external protective coating; the integrity that keeps external protective coating; and adopt special process to strengthen the local galvanic protection performance of the large tube coupling weld seam of relay well, guarantee that the weather resistance protection life-span at this position is consistent with the pipeline overall durability life-span.

(2) the long distance steel push pipe of heavy caliber cathode protection technology research

The galvanic protection construction technology of push pipe pipeline must keep the non-excavating technological characteristics of construction, the impact on earth's surface and destructiveness is down to minimum, should reach the normal operation of not disturbing the earth's surface facility and not destroy the requirement such as Landscape.In addition; this cathodic protection system is except the protection of satisfying native system requires; also should take into account adjacent facility is not produced negative influence, can not produce excessive stray current to other adjacent facility because self-protection requires and disturb, affect the safe operation of adjacent facility.At present, still do not have ripe, with protective coating and galvanic protection technical application that non-excavating construction is complementary, cause integrity difficult realization of the corrosion control safeguard system of steel push pipe, be a bottleneck difficult problem of weather resistance protection at present this technology implementation.

If push pipe buried pipeline position is darker, mostly above 10 meters.Earth's surface and underground installation through the area are complicated, have both comprised the view highway section, and traffic main artery and residential district are arranged again, and therefore, the protection to the earth's surface when implementing galvanic protection is very crucial.In addition, the underground in addition multiple Infrastructure such as electric power, telecommunications, oil transportation, the impressed current method may cause interference to it, and the final-period management difficulty is also very large.Therefore, suggestion adopts the sacrificial anode method to carry out galvanic protection.And traditional galvanic anode protection method is followed and is buried sacrificial anode in the pipeline laying process underground and carry out, and for the husky push pipe pipeline of the green grass of non-excavating construction, the method can't be implemented.If can adopt Trenchless Technologies to implement galvanic anode protection for the heavy caliber pipe-jacking pipeline, will fundamentally solve the integrity difficult problem of weather resistance protection system.

Long-distance Water Transmission Pipeline adopts the steel jacking pipe construction process completely, and takes corresponding monitoring, detection and safeguard procedures; Will significantly prolong pipeline operation life, reduce the integrated operation cost, bring great economic benefit and social benefit.

People expect to obtain the better underground piping system cathodic protection system of a kind of technique effect.

Summary of the invention

The purpose of this invention is to provide the better underground piping system cathodic protection system of a kind of technique effect.

The invention provides a kind of underground piping system cathodic protection system, be specially the feed coupling device that is arranged on theunderground pipeline 1 and the combination of cathodic protector; It is characterized in that: described underground piping system is constructed as follows with cathodic protection system:feeder cable 401,feed connecting joint 402,sacrificial anode 7; Wherein: the lower end offeeder cable 401 is fixedly connected with and consists of withunderground pipeline 1 outer wall byfeed connecting joint 402 and is electrically connected, andsacrificial anode 7 is fixedly connected on the other end offeeder cable 401;

Water string 5 is placed in theouter pillar 2, and its front end stationary cloth is equipped withfeed connecting joint 402, and feed connectingjoint 402 andunderground pipeline 1 outer wall close contact and mobile are in order to carry out feed connecting joint 402 andunderground pipeline 1 welding operation between the two; Being constructed as follows of water string 5:screw rod 501,muff joint 502, telescopicjoint pipe 503, sleevepipe front tab 504,feed connecting joint 402; Wherein: front four all is hollow tubular structures; Between telescopicjoint pipe 503 and thefeed connecting joint 402 by sleevepipe front tab 504, be connected to the one of coaxial line; Pre-connection hasfeeder cable 401 on thefeed connecting joint 402, andscrew rod 501 is at least one section, between thedifferent screw rods 501 or/and be connected to the one of coaxial line betweenscrew rod 501 and the telescopicjoint pipe 503 bymuff joint 502;

Sacrificial anode 7 concrete formation withunderground pipeline 1 byfeeder equipment 4 are electrically connected, and finally consist of the Cathodic protection of underground pipeline system; Describedsacrificial anode 7 is specially segmentation structure, and the outside is that sacrificial anode material layer 701, inside are the steel cylinder 702 of hollow; Be threaded connection the electrical connection between the formation steel cylinder 701 between each section, topmost and bottom are provided with the shutoff 704 of sealing usefulness, and top is drawnfeeder cable 401 and connectedfeeder equipments 4 and final andunderground pipeline 1 formation electrical connection.

Described underground piping system cathodic protection system is characterized in that: sacrificial anode material layer 701 material satisfy following several requirements one or a combination set of: magnesium anode, zinc anode, aluminium-zinc-indium are the alloy sacrificial anode, zinc-aluminium-cadmium alloy sacrificial anode.

Described underground piping system cathodic protection system is characterized in that: the arrangement pitch ofsacrificial anode 7 is 50-500 rice; Arrange in pairs or single layout;

Feed connecting joint 402 is arranged onwhole water string 5 leading portions, and feed connecting joint 402 front ends are provided with the inner chamber of sealing, and its nose thickness is 0.2-8mm; The front end face of feed connecting joint 402 closed inner chambers is the conical surface, and the cross section of the conical surface reduces and reduces with the front end face of distancefeed connecting joint 402.

Described underground piping system cathodic protection system is characterized in that:

Satisfying following resistivity and welding strength after feed connecting joint 402 andunderground pipeline 1 are welded and fixed requires: resistivity requires at 0.1-0.01 ohm; Welding strength requires: use the external forcetractive feeder cable 401 of 50-200kg, require can not destroy the welding quality of feed connecting joint 402 andunderground pipeline 1.

Also satisfy following requirement in feed connecting joint 402 andunderground pipeline 1 weld: usecementer 8 to add the protection filler at feed connecting joint 402 places with protectionfeed connecting joint 402.

Underground piping system of the present invention with cathodic protection system under the technical background of the non-jacking construction of underground pipeline, the construction technology of application of advanced and obtain final underground piping system cathodic protection system.Its versatility, effect is remarkable, and the constructability operation is maintainable good.The present invention is a systems engineering, and the content that relates to is more; Technology maturity is higher, has expected very huge economic worth and social value.

Description of drawings

The present invention is further detailed explanation below in conjunction with drawings and the embodiments:

Fig. 1 is earth's surface positioning principle synoptic diagram;

Fig. 2 is for adding the principle of work synoptic diagram ofouter pillar 2;

Fig. 3 is clear well principle of operation synoptic diagram;

Fig. 4 is the solder joint inspection principle schematic;

Fig. 5 is the enlarged view of local structure among Fig. 4, that is: detect and fill with near (301) local structure enlarged view;

Fig. 6 is the principle schematic that addswater string 5 in theoutside pillar 2;

Fig. 7 is the structural representation ofwater string 5;

Fig. 8 is the structural representation sketch of feed connecting joint (402) in thewater string 5;

Fig. 9 is the remote welding principle schematic;

Figure 10 is the structural representation ofwelding gun 6;

Figure 11 is the weld position partial enlarged drawing of Fig. 9;

Figure 12 is that remote welding checks the principle schematic that whether satisfies resistivity and welding strength requirement afterwards;

Figure 13 is perfusion protection filler principle schematic;

Figure 14 is the partial enlarged drawing of Figure 13 bottom border circular areas;

Figure 15 is for drawing off the synoptic diagram behind the water string (5);

Figure 16 is after feeder line construction underground part is finished protecting tube (2) is upwards mentioned former

Figure 17 is thatfeeder equipment 4 is alongunderground pipeline 1 construction synoptic diagram;

Figure 18 is the corrosion synoptic diagram of buried steel pipe in soil;

Figure 19 is the principle schematic thatsacrificial anode 7 is arranged alongunderground pipeline 1 both sides by means offeeder equipment 4, and among Figure 19,underground pipeline 1 should be cross section, representsunderground pipeline 1 but be reduced to a circular outline;

Figure 20 is the sacrificial anode structure diagram of the section of mediating;

Figure 21 is the local structure synoptic diagram withsacrificial anode 7 topmosts one end of auxiliary structure for lifting;

Figure 22 is the right view of Figure 21;

Figure 23 is the current potential-PH figure of steel;

Figure 24 is one of steel pipe piling galvanic protection basic structure schematic diagram;

Figure 25 is two of steel pipe piling galvanic protection basic structure schematic diagram.

Embodiment

Embodiment 1

A kind of underground piping system cathodic protection system is specially the feed coupling device that is arranged on theunderground pipeline 1 and the combination of cathodic protector; Described underground piping system is constructed as follows with cathodic protection system:feeder cable 401, feed connecting joint 402,sacrificial anode 7; Wherein: the lower end offeeder cable 401 is fixedly connected with and consists of withunderground pipeline 1 outer wall by feed connecting joint 402 and is electrically connected, andsacrificial anode 7 is fixedly connected on the other end offeeder cable 401;

Water string 5 is placed in theouter pillar 2, and its front end stationary cloth is equipped with feed connecting joint 402, and feed connecting joint 402 andunderground pipeline 1 outer wall close contact and mobile are in order to carry out feed connecting joint 402 andunderground pipeline 1 welding operation between the two; Being constructed as follows of water string 5: screwrod 501, muff joint 502, telescopicjoint pipe 503, sleevepipe front tab 504, feed connecting joint 402; Wherein: front four all is hollow tubular structures; Between telescopicjoint pipe 503 and the feed connecting joint 402 by sleevepipe front tab 504, be connected to the one of coaxial line; Pre-connection hasfeeder cable 401 on the feed connecting joint 402, and screwrod 501 is at least one section, between thedifferent screw rods 501 or/and be connected to the one of coaxial line betweenscrew rod 501 and the telescopicjoint pipe 503 by muff joint 502;

Sacrificial anode 7 concrete formation withunderground pipeline 1 byfeeder equipment 4 are electrically connected, and finally consist of the Cathodic protection of underground pipeline system; Describedsacrificial anode 7 is specially segmentation structure, and the outside is that sacrificial anode material layer 701, inside are the steel cylinder 702 of hollow; Be threaded connection the electrical connection between the formation steel cylinder 701 between each section, topmost and bottom are provided with the shutoff 704 of sealing usefulness, and top is drawnfeeder cable 401 andconnected feeder equipments 4 and final andunderground pipeline 1 formation electrical connection.

Described underground piping system is with in the cathodic protection system, and sacrificial anode material layer 701 material satisfy following several requirements one or a combination set of: magnesium anode, zinc anode, aluminium-zinc-indium are the alloy sacrificial anode, zinc-aluminium-cadmium alloy sacrificial anode.

Described underground piping system is with in the cathodic protection system, and the arrangement pitch ofsacrificial anode 7 is 50-500 rice; Arrange in pairs or single layout;

Feed connecting joint 402 is arranged onwhole water string 5 leading portions, and feed connecting joint 402 front ends are provided with the inner chamber of sealing, and its nose thickness is 0.2-8mm; The front end face of feed connecting joint 402 closed inner chambers is the conical surface, and the cross section of the conical surface reduces and reduces with the front end face of distance feed connecting joint 402.

Described underground piping system is with in the cathodic protection system, and satisfy following resistivity and welding strength and require after feed connecting joint 402 andunderground pipeline 1 are welded and fixed: resistivity requires at 0.1-0.01 ohm; Welding strength requires: use the external forcetractive feeder cable 401 of 50-200kg, require can not destroy the welding quality of feed connecting joint 402 andunderground pipeline 1.

Also satisfy following requirement in feed connecting joint 402 andunderground pipeline 1 weld: usecementer 8 to add the protection filler at feed connecting joint 402 places with protection feed connecting joint 402.

The described underground piping system of present embodiment with cathodic protection system under the technical background of the non-jacking construction of underground pipeline, the construction technology of application of advanced and obtain final underground piping system cathodic protection system.Its versatility, effect is remarkable, and the constructability operation is maintainable good.Present embodiment is a systems engineering, and the content that relates to is more; Technology maturity is higher, has expected very huge economic worth and social value.

The underground piping system that present embodiment is relevant is described below with cathodic protector constructional method spy: described underground piping system satisfies following requirement successively with the cathodic protector constructional method:

1. at first from the earth'ssurface 101 of the outside top ofunderground pipeline 1 to the direction boring ofunderground pipeline 1, boredia 10～1200mm, preferred: 50-250mm, the outer wall of the throughunderground pipeline 1 in this hole but should not destroyunderground pipeline 1; Each hole arranges directly over it that alongunderground pipeline 1 spacing between each hole is 100-500m, and is preferred: 150-300m; With reference to figure 1.

The process of holing to the direction ofunderground pipeline 1 from the earth's surface ofunderground pipeline 1 outside top satisfies following requirement: 10～20 meters of hole depths, and corresponding bore dia is 50～200mm;

Boring directly overunderground pipeline 1, axially bored line direction and underground utilities cross section geometric centre are exactly that axis is as far as possible close even overlap with it for circular pipeline

Boring method: at first above the non-excavating construction pipeline, determine to carry out the point of surface drilling, then carry out drilling operation;

Punching requires: withunderground pipeline 1 vertical direction on, this point should be directly over vertical direction;

Then 2. theouter pillar 2 of hollow be installed in the hole that said process gets out, and made the front end ofouter pillar 2 touchunderground pipeline 1 outer wall and jointly consisted of the tubular cavity of relative closure byouter pillar 2 andunderground pipeline 1 outer wall;Outer pillar 2 is specially steel pipe or plastics tubing; Its specification is: intracavity diameter 50-200mm, and preferred: 108mm;Outer pillar 2 inside may be filled with the contents such as somesilts 102 and sewage; Referring to Fig. 2;

The process ofpillar 2 satisfies following requirement outside input and the installation in the hole:

Outer pillar 2 is sent in the hole until the front end ofouter pillar 2 arrives and touchunderground pipeline 1 outer wall; The diameter dimension ofouter pillar 2 is from 100～150mm;Outer pillar 2 is steel pipe or plastics tubing, and the pipe end of theouter pillar 2 of contactunderground pipeline 1 is fixedly installed the insulated enclosure pad that is useful on buffer protectionunderground pipeline 1 outer wall;Outer pillar 2 is segmental structure, is thread joined structure between each section;Outer pillar 2 outside surfaces after the whole assembling are coated with protective coating;

3. clear well: during clear well, fromouter pillar 2 center cavities, the cleaning equipment of remote control is sent to the shaft bottom and isunderground pipeline 1 outer wall and sentence just cleaning and be positioned atouter pillar 2 inner foreign material nearunderground pipeline 1 outer walls; Referring to Fig. 3;

Clear well requires: will affect thesilt 102 of welding effect and sewage etc. and clear out ofouter pillar 2, and fill this with clear water or air simultaneously and locate near the position to be welded space;

Clear well specifically adopts high pressure water or high-pressure air as working medium; Concrete clear well method satisfies following requirement one or a combination set of: one, near if the soil poor fluidity the underground pipeline 1, the clear well treating method that adopts is: slightly mention outer pillar 2, the requirement for height that improves is 10～100mm, with pressurized air or high pressure water by means of clear well casing 103 from the input of outer pillar 2 upper ends and deliver to the shaft bottom in order to add pressurized air or high pressure water, need pressure at 2 more than the normal atmosphere, silt 102 ejects from the shaft bottom the most at last; Then when keeping pressure, put back to that outer pillar 2 makes it contact with underground pipeline 1 outer wall until outer pillar 2 and underground pipeline 1 close contact, so that the chamber of formation relative closure and can guarantee that outer pillar 2 interior cleanings are beneficial to follow-up welding process and carry out; They are two years old, if removing mud by the shaft bottom is difficult for, then outside guaranteeing, between pillar 2 and the underground pipeline 1 as far as possible in the close contact, pressurized air or high pressure water are upwards ejected mud and finally ejected by well head from outer pillar 2 inside at shaft bottom output squeezing air or high pressure water by the clear well casing 103 that is deep into outer pillar 2 inside; The pressure that pressurized air or high pressure water need requires at 2 more than the normal atmosphere, and outer pillar 2 and underground pipeline 1 outer wall all the time the close contact chamber that forms upper opening are beneficial to clearly well and can stopping that dirt enters in the outer pillar 2 behind clear well;

4. solder joint inspection: the solder joint that will weld between tofeeder equipment 4 andunderground pipeline 1 after clear well checks that in advance the particular exam content is to comprise the horizontal situation at protectedunderground pipeline 1 place and the silt residual volume at feeding point place; Referring to Fig. 4,5;

The requirement of solder joint inspection is: select atest rod 3, being constructed as follows of test rod 3: detect and fill with 301, detectmaterial 302, handle 303; Wherein: handle 303 is shaft-like, and handle 303 front ends are being arranged detection filling 301, and the part of detectingmaterial 302 is arranged on to detect fills with 301 inside, and another part protrudes into detection filling 301 outsides towardswhole test rod 3 front ends; Detectingmaterial 302 meets the demands: one, nonelastic, after being squeezed, deform and deformation irrecoverable; Its two, can keep in a long time the software state, and not lose characteristic through water soaking; Its three, this elastomerics itself has a little viscosity, the silt at part tube wall place can be glued in order to further clear up the weld;

During bottom, hole intest rod 3 extend intoouter pillar 2, detect the outer wall of filling with the 301 inner detection materials that arrange 302 and theunderground pipeline 1 that is detected occur after the extruding according to its with the contact surface viscous deformation of the outer wall ofunderground pipeline 1 after the outer pillar axis deviation degree of concrete shape judgement whether up to standard; According to detect the particular case that adheres to silt etc. on thematerial 302 judge remaining quantity of sand and mud what and clear up whereby the weld.

5. descend water string 5:water string 5 is put intoouter pillar 2, and make fixed and arranged at the feed connecting joint 402 andunderground pipeline 1 outer wall close contact and not mobile ofwater string 5 front ends, then carry out welding operation; Referring to Fig. 6,7,8;

Being constructed as follows of described water string 5: screwrod 501, muff joint 502, telescopicjoint pipe 503, sleevepipe front tab 504, feed connecting joint 402; Wherein:

Front four all is hollow tubular structures; Between telescopicjoint pipe 503 and the feed connecting joint 402 by sleevepipe front tab 504, be connected to the one of coaxial line;

Pre-connection hasfeeder cable 401 on the feed connecting joint 402, and screwrod 501 is at least one section, between thedifferent screw rods 501 or/and be connected to the one of coaxial line betweenscrew rod 501 and the telescopicjoint pipe 503 by muff joint 502;

Feed connecting joint 402 is arranged onwhole water string 5 leading portions, and feed connecting joint 402 front ends are provided with the inner chamber of sealing, and its nose thickness is 0.2-8mm; The front end face of feed connecting joint 402 closed inner chambers is the conical surface, and the cross section of the conical surface reduces and reduces with the front end face of distance feed connecting joint 402; Be fixed with inadvance feeder cable 401 on the feed connecting joint 402;

6. remote welding: use welding plant that the metal of the feed connecting joint 402 ofwater string 5 front ends andunderground pipeline 1 partly is welded together to form electrical connection; Participate in Fig. 9,10,11;

Satisfy following requirement in the process of remote welding: use weldinggun 6 and thefeeder cable 401 that is fixed in advance on the feed connecting joint 402 consist of the electrical connection loops in order to carry out the remote welding operation, and feed connecting joint 402 andunderground pipeline 1 are welded together the formation electrical connection;

The process of welding satisfies following requirement: at first thewelding gun 6 of clamping welding rod is sent intowater string 5 inside and is made the electrode tip of its front end near the inner chamber front end of feed connecting joint 402, then begin welding, in order to the metal of feed connecting joint 402 andunderground pipeline 1 partly is welded together to form electrical connection;

The outside of thefeeder cable 401 after the welding extends to the earth's surface always;Feeder cable 401 extends to the physical length on earth's surface should be more than or equal to 110% degree of depth of be used for placing the hole ofouter pillar 2;

Being constructed as follows of welding gun 6:electrode grip 601, welding gun bar 602,electric connection line 603; Wherein:electrode grip 601 fixed and arranged are at the front end of welding gun bar 602, and welding gun bar 602 is tubulose, and an end ofelectric connection line 603 is connectingelectrode grip 601, and welding gun bar 602 inner chambers ofelectric connection line 603 by tubulose are drawn out to the outside and are connected on the welding machine; Connect into power circuit in order to finish welding operation by means of the following structure that is linked in sequence successively:electric connection line 603,electrode grip 601,welding rod 604, feed connecting joint 402,feeder cable 401, welding machine.

7. after remote welding, check whether satisfy resistivity and welding strength; The qualified requirement of particular exam is: resistivity requires at 0.1-0.01 ohm; Welding strength requires: use the external forcetractive feeder cable 401 of 50-200kg, require can not destroy the welding quality of feed connecting joint 402 andunderground pipeline 1; Referring to Figure 12.

8. after remote welding is also qualified, also require to carry out successively following two kinds of operations:

One, grouted aggregate concrete: after drawing offwater string 5, usecementer 8 to add the protection filler at feed connecting joint 402 places with protection feed connecting joint 402;

Cementer 8 is constructed as follows: groutingbar 801, grouting 802; Wherein: groutingbar 801 be tubular structure, grouting 802 be arranged ingrouting bar 801 front ends and its front opening to feed connecting joint 402 places perfusion protection filler to protect feed connecting joint 402; Filler is specially concrete, referring to accompanying drawing 13,14;

After the grouting,feeder cable 401 is introduced near the controlling box that is arranged on the earth's surface.

The well that diameter is limited is only bored in this invention on the earth's surface, avoided adopting digging mode to the destruction of earth's surface facility.Atunderground pipeline 1 open interior, do not reduced the damage to underground pipeline 1.In addition, can implement the feeder equipment construction and process according to the galvanic protection offeeder equipment 4 for the less underground pipeline of caliber 1.Take thisfeeder equipment 4 as the basis, can also make up galvanic protection and the Monitoring systems of various ways;

Its two, draw off water string 5: postwelding detect qualified after, draw off the rest part ofwater string 5 except feed connecting joint 402 andfeeder cable 401; Requirement keep leading portion be welded to connect onunderground pipeline 1 feed connecting joint 402 andfeeder cable 401 fixed thereon in advance, basset in the upper end offeeder cable 401 so that application afterwards; Referring to Figure 15;

Can be for being threaded between other parts of feed connecting joint 402 andwater string 5, other parts ofwater string 5 can be being threaded of segmentation, the rotation direction that is threaded between each section is identical; Between each section be threaded rotation direction from the most front one section with feed connecting joint 402 between the rotation direction that is threaded different;

9. then carry out a kind of of following two kinds of operations: one, protectingtube 2 is upwards mentioned a segment distance: 10-50cm, so that silt soil on every side can directly contact with feed connecting joint 402; Its two, directremoval protecting tube 2;

10.sacrificial anode 7 constructions: near in advance punchingunderground pipeline 1, imbedsacrificial anode 7, and byfeeder equipment 4 it is electrically connected withunderground pipeline 1 formation, and finally consist of the Cathodic protection of underground pipeline system; The arrangement pitch ofsacrificial anode 7 is 50-500 rice; Arrange in pairs or single layout;

Sacrificial anode 7 is segmental structure, being constructed as follows of each section sacrificial anode 7: sacrificial anode material body 701, support steel cylinder 702, sacrificial anode joint 703, sacrificial anode counterweight; Wherein: sacrificial anode material body 701 is tubular, it is outside that it is fixedly installed on the outer side that supports steel cylinder 702, and each section is connected to one by being fixed on the sacrificial anode joint 703 order series connection of supporting on the steel cylinder 702 each other in thesacrificial anode 7 of segmental structure; Each sectionsacrificial anode 7 has a sacrificial anode joint 703 at least; The sacrificial anode counterweight fixed and arranged that anti-floating is used is in supporting steel cylinder 702 internal cavities or on support steel cylinder 702 inwalls;

Whensacrificial anode 7 has 2 sacrificial anode joints 703, its the two be arranged in the two ends of thesacrificial anode 7 of segmentation, one of them sacrificial anode joint 703 has female thread structure, be provided with the external thread structure of protrusion on another sacrificial anode joint 703, cooperatively interacting with two sacrificial anode joints 703 of female thread structure and external thread structure respectively on adjacent two sectionssacrificial anodes 7 connects as one;

That end away fromsacrificial anode 7 main parts that is arranged on that sectionsacrificial anode 7 of end also is provided with the antirust waterproof that is fixed on thesacrificial anode 7 plug;

Sacrificial anode material body 701 is specifically selected by multiple material: magnesium anode, zinc anode, aluminium-zinc-indium are the alloy sacrificial anode, zinc-aluminium-cadmium alloy sacrificial anode.Its structure is referring to accompanying drawing 20;

Figure 21,22 is respectively a kind of possible structure of wholesacrificial anode 7 topmosts, with the auxiliary structure of lifting and the structure of electrical connection of being used for; The auxiliary structure that is used for lifting is referring to Figure 21,22 suspension ring structure, the structure of electrical connection in Figure 21,22 for drawing.

Present embodiment only bores the well that diameter is limited on the earth's surface, avoided adopting digging mode to the destruction of earth's surface facility.Atunderground pipeline 1 open interior, do not reduced the damage to underground pipeline 1.In addition, can implement the feeder equipment construction and process according to the galvanic protection offeeder equipment 4 for the less underground pipeline of caliber 1.Take thisfeeder equipment 4 as the basis, can also make up galvanic protection and the Monitoring systems of various ways.

The described sequence of operations process of present embodiment (relating to: cathodic protection system anode well, power feed hole, monitoring holes position) preferably also further satisfies following requirement:

1, active well spacing: 1016 meters, 10 groups of sacrificial anodes are installed on the single pipeline, open 10 anode mounting shafts.The aperture is greater than 400mm, and hole width between centers pipe outer wall is not less than 1.8m.

2, the anode mounting shaft degree of depth is (h+3) m, and h is that the earth's surface is to managing the waist degree of depth.

3, anode is installed in every pipeline both sides, adopts oversheath that anode is installed.

4, the anode well position can be adjusted along pipeline laying direction appropriateness, and setting range is (L ± 20) m, and L is anode well and the active well spacing of in advance design.

5, the feed mounting hole site is directly over pipeline, near the anode mounting shaft, and feed casing diameter 108mm.

6, monitoring holes be positioned at directly over the pipeline, the adjacent anode point midway, monitoring holes casing diameter 108mm.

7, single pipe is opened 10 of anode well, 5 of power feed hole, and 4 of test holes are counted 19,38 of two-wire meters.

The present embodiment versatility, effect is remarkable, the constructability operation; The present invention is a systems engineering, and the content that relates to is more; Technology maturity is higher, has expected very huge economic worth and social value.

Claims (5)

1. underground piping system cathodic protection system is specially the feed coupling device that is arranged on the underground pipeline (1) and the combination of cathodic protector; It is characterized in that: described underground piping system is constructed as follows with cathodic protection system: feeder cable (401), feed connecting joint (402), sacrificial anode (7); Wherein: the lower end of feeder cable (401) is fixedly connected with and consists of with underground pipeline (1) outer wall by feed connecting joint (402) and is electrically connected, and sacrificial anode (7) is fixedly connected on the other end of feeder cable (401);

Water string (5) is placed in the outer pillar (2), its front end stationary cloth is equipped with feed connecting joint (402), feed connecting joint (402) and underground pipeline (1) outer wall close contact and mobile are in order to carry out the welding operation between the two of feed connecting joint (402) and underground pipeline (1); Being constructed as follows of water string (5): screw rod (501), muff joint (502), telescopic joint pipe (503), sleeve pipe front tab (504), feed connecting joint (402); Wherein: front four all is hollow tubular structures; Between telescopic joint pipe (503) and the feed connecting joint (402) by sleeve pipe front tab (504), be connected to the one of coaxial line; The upper pre-connection of feed connecting joint (402) has feeder cable (401), screw rod (501) is at least one section, between the different screw rod (501) or/and be connected to the one of coaxial line between screw rod (501) and the telescopic joint pipe (503) by muff joint (502);

Sacrificial anode (7) specifically forms with underground pipeline (1) by feeder equipment (4) and is electrically connected, and finally consists of the Cathodic protection of underground pipeline system; Described sacrificial anode (7) is specially segmentation structure, and the outside is that sacrificial anode material layer (701), inside are the steel cylinder of hollow (702); Be threaded connection the electrical connection that consists of between the steel cylinder (701) between each section, topmost and bottom are provided with the shutoff (704) of sealing usefulness, and top is drawn feeder cable (401) and connected feeder equipment (4) and final and underground pipeline (1) formation electrical connection.

2. according to the described underground piping system cathodic protection system of claim 1; it is characterized in that: sacrificial anode material layer (701) material satisfies following several requirements one or a combination set of: magnesium anode; zinc anode, aluminium-zinc-indium are the alloy sacrificial anode, zinc-aluminium-cadmium alloy sacrificial anode.

3. according to the described underground piping system cathodic protection system of claim 1, it is characterized in that: the arrangement pitch of sacrificial anode (7) is 50-500 rice; Arrange in pairs or single layout;

Feed connecting joint (402) is arranged on the leading portion of whole water string (5), and feed connecting joint (402) front end is provided with the inner chamber of sealing, and its nose thickness is 0.2-8mm; The front end face of feed connecting joint (402) closed inner chamber is the conical surface, and the cross section of the conical surface reduces and reduces with the front end face of distance feed connecting joint (402).

4. according to the described underground piping system cathodic protection system of claim 3, it is characterized in that:

Satisfying following resistivity and welding strength after feed connecting joint (402) and underground pipeline (1) are welded and fixed requires: resistivity requires at 0.1-0.01 ohm; Welding strength requires: use the external force tractive feeder cable (401) of 50-200kg, require can not destroy the welding quality of feed connecting joint (402) and underground pipeline (1).

5. according to one of them described underground piping system cathodic protection system of claim 1-4, it is characterized in that: also satisfy following requirement in feed connecting joint (402) and underground pipeline (1) weld: use cementer (8) to locate to add the protection filler with protection feed connecting joint (402) at feed connecting joint (402).

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