RU2530576C2 - Deep anode bed - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is related to the area of electrochemical corrosion protection for underground structures and pipelines. The anode bed is made as a string of anode earthing electrodes interconnected in-series electrically and mechanically, and each of them comprises the central metal electrode coupled to the previous and next ones into a common electrical conductor and a bar with equal strength, at that each anode earthing electrode represents a pipe-in-pipe structure consisting of the central electrode made as a pipe and an external electrode made as a coaxial cylinder; at inner surface of the central electrode there is a current lead and in gaps between cylinder ends there are heat-shrinking cup-type seals, annular space is filled with a filler consisting of pyritic slag.

EFFECT: design of the anode bed ensures simple mounting, even distribution of current, low resistance, protection of feed cables and contact pairs from mechanical damage and corrosion attack of ground electrolyte as well as sufficient bending strength and stiffness, reliability and durability.

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Description

The invention relates to the field of protection of underground structures and pipelines from electrochemical corrosion, in particular to deep anode grounding conductors.

A deep anode earthing switch is known, containing two concentrically arranged steel pipes, the space between which is filled with coke breeze, and steel elements are fixed to the inner pipe along the entire length of its working part in the form of disks covering the pipe (a.s. SU 852969 C23F 13/00) .

A disadvantage of the known deep anode ground electrode system is a significant metal consumption, the complexity of assembly and installation, due to the low degree of industrialization of the device: in the factory, only holes in the pipes and installation of disks can be made - everything else is done in the field at the installation site.

The closest to the invention in technical essence and the achieved results is a borehole anode earthing switch, made in the form of a garland of separate anode earthing switches that are electrically and mechanically connected in series with each other, completely ready for use, each of which contains a central metal electrode surrounded by an activator layer made in in the form of a cylinder coaxial to the electrode from a mixture of particles of electrically conductive granular, porous granular material and connected to the leading and subsequent electrodes into a single electrical conductor and a single rod of equal strength along the length, characterized in that the activator mixture consists of fractions of particles selected by mass fraction and size, and a thermoplastic binder, and the gaps between the ends of the activator cylinders of adjacent anode grounding conductors are filled with an activator or a related material to the common outer surface of the cylinders, several long metal plates fixed in the elah cylinder lengths along the electrode activator and uniformly around the circumferential direction (AS RU 2196190 C23F 13/16).

The disadvantages of this borehole anode ground electrode system are the inconvenience of installation, the possibility of cable breakage during backfill, susceptibility of current leads to corrosion damage, short service life.

An object of the invention is the creation of a deep anode ground electrode system, the design of which provides ease of installation, protection of supply cables and current leads from mechanical damage and the corrosive effects of soil electrolyte, as well as the reliability and durability of the anode ground electrode system.

The problem is solved in that in a deep anode ground electrode made in the form of a garland of separate anode ground electrodes that are electrically and mechanically connected in series with each other, they are completely ready for use, each of which contains a central metal electrode connected to the previous and subsequent electrodes in a single electrical conductor and a rod of equal strength along the length, according to the invention, each individual anode earthing switch is a pipe-in-pipe construction consisting of th of the center electrode formed in the form of a tube, and the outer electrode formed as a cylinder coaxial to it; a current lead is located on the inner surface of the central electrode; in the intervals between the ends of the cylinders, heat-shrinkable cuffs are mounted, the annular space is filled with a filler consisting of pyrite cinder.

The drawing shows a deep anode ground electrode.

и толщиной δ₃=6 мм, служащее для надежной фиксации анодного заземлителя при подъеме и спуске в скважину. Межтрубное пространство заполнено наполнителем 4, состоящим из пиритного огарка, также выполняющего функцию электрода. Токоввод 5 расположен на внутренней поверхности центрального электрода 1 на расстоянии l₄=120 мм от конца трубы.The deep anode ground electrode system consists of separate anode ground electrode systems, which in turn are a pipe-in-pipe construction, with the central electrode 1, length l ₁ = 6000 mm, diameter d ₁ = 60 mm and wall thickness δ ₁ = 10 mm, and outer cylinder 2, length l2 = 5400 mm, diameter d ₂ = 146 mm and wall thickness δ ₂ = 10 mm, bounded at both ends by ends. At a distance l ₃ = 50 mm from the upper end of the outer cylinder 2, a ring 3 is welded with a diameter of d ₃ = 159 mm, a height $$l_3^{\text{'}\text{'}}=\mathrm{one\; hundred}mm$$

and a thickness of δ ₃ = 6 mm, which serves for reliable fixation of the anode ground electrode during ascent and descent into the well. The annular space is filled with filler 4, consisting of a pyrite cinder, also performing the function of an electrode. The current lead 5 is located on the inner surface of the Central electrode 1 at a distance l ₄ = 120 mm from the end of the pipe.

The central electrodes 1 of the anode ground electrodes are interconnected by welding and form a single electrical conductor and a rod of equal strength along the length. The gaps between the ends of the outer cylinders 2 are insulated with heat-shrinkable cuffs 6.

The deep anode ground electrode system is assembled from separate anode ground electrodes manufactured at the factory and is completely ready for use both in the garland of the deep anode ground electrode system and separately. The connection of the central electrodes 1 to each other is carried out during the assembly of the deep anode ground electrode in series as it is lowered into the well. Heat-shrinkable sleeves 6 are also sequentially mounted between the ends of the outer cylinders 2. The supply cables 7 are led to the carpet of the anode ground electrode 8 through the central electrode 1, and then through the pipe 9 insulated with paint and varnish coating. The space between the anode ground electrode and the well wall is filled with activator 10.

The space between the insulated pipe 9 and the wall of the well is covered with gravel 11. The carpet of the deep anode ground electrode system is connected to the cathodic protection station via a connecting cable 12.

The device operates as follows.

When a deep anode ground electrode is connected to the cathode station, an electric current arises between the ground electrode and the protected structure, under the influence of which an electrochemical process takes place on the anode ground electrode.

According to RD 153-39.4-039-99 “Design standards for ECP of main pipelines and MN sites," the service life of the anode ground, depending on the nature of the soil, is 10-15 years. The proposed design under similar conditions provides a service life of 25-30 years. This result is achieved by isolating the supply cables and current leads from mechanical damage and soil corrosion, as well as the low rate of electrochemical dissolution of the filler.

Claims (1)

A deep anode ground electrode made in the form of a garland of separate anode ground electrodes that are electrically and mechanically connected in series with each other, each of which contains a central metal electrode connected to the previous and subsequent electrodes into a single electrical conductor and a rod of equal strength along the length, characterized in that each individual anode the ground electrode contains a central metal electrode made in the form of a pipe, and an outer electrode made in the form of a cylinder coaxial with By calling the “pipe in pipe” design, a current lead is located on the inner surface of the central electrode, heat-shrinkable cuffs are mounted between the ends of the cylinders, the annular space is filled with a filler consisting of pyrite cinder.

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