JPH0762264B2 - Anode device for cathodic protection by external power supply method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an anode device used for galvanic protection of an underground buried object by an external power supply method.

[Conventional technology]

Conventionally, various types of anode devices have been known to be used for galvanic protection of underground buried objects such as various tanks, foundation piles, gas and petroleum pipes by an external power supply method, and particularly, in recent years, their constituent elements have been known. As an anode device which can be replaced relatively easily, the one shown in a schematic sectional view in FIG. 3 has been proposed.

This conventional anode device is, as shown in the figure, a tubular casing made of synthetic resin, which is inserted into a cylindrical hole 1 drilled at a predetermined position in the soil and has a plurality of through holes 3 for energization in the lower part. 2 and a plurality of high silicon cast iron and graphite, which are fixed in the tubular casing 2 by being filled with a backfill such as carbon powder, ferrite, metal oxide, etc. Anode 4 and the through hole 3 for energization
A conductive tube body 5 made of steel or other metal fitted to the lower outer surface of the tubular casing 2 so as to close the
A backfill, which is formed by inserting the tubular casing 2 into the cylindrical hole 1 and is separately filled in the inner space and the outer space of the tubular casing 2, that is, an inner bag. A conductive wire 7 basically composed of a fill 6a and an outer backfill 6b, and drawn from each of the anodes 4.
Is coupled to the positive electrode of the rectifier 8, and the negative electrode is coupled to a predetermined place of the corrosion-prevented body A such as an oil tank or underground pipe, and the corrosion-prevented current is passed through the corrosion-prevented body A so that the corrosion protection is performed. In such a device,
The anode embedded in the tubular casing 2 is consumed,
When replacing this, water is sucked up by pouring water into the backfill in the tubular casing 2 to make the inside of the tubular casing hollow, and then the pulling-up and replacing work of the anode is performed.

[Problems to be solved by the invention]

In such a conventional device, the metal tubular body 5 covering the outer periphery of the perforated portion of the tubular casing 2 undergoes corrosion due to its action while the anticorrosive current is flowing, and therefore, after being used for a long period of time. When the tubular body 5 finally has a hole, and therefore the anode is replaced by the above method in such a state, the backfill 6a on the outer side of the backfill 6a is sucked when sucking the backfill 6a in the tubular casing 2. Also sucking up continuously through the holes generated by the corrosion to destroy the layer of the outer backfill 6b, and it becomes difficult to secure a space necessary for replacing the anode 4 in the tubular casing 2. Further, when the anode 4 is fixed inside the tubular casing 2 forming the well wall and it is difficult to take out the anode 4, reaming with a core tube is required. Easy casing 2 made of synthetic resin forming the well wall is damaged by such operations, when the casing 2 is broken, a great deal of labor and effort to ensure the well wall has a problem that it takes.

[Means for solving problems]

This invention, in the cathodic protection anode device by the external power supply system as described above, while stably maintaining a space of a sufficient size in its burying place during the replacement work of the anode,
For the purpose of strengthening the well wall that surrounds the space, a cylindrical hole drilled at a predetermined position in the soil and the upper part inserted into this hole has insulating properties and the remaining lower part is An electrically conductive tubular casing, an electrode anticorrosive anode inserted in the tubular casing, and a conductive material powder (for example, a carbonaceous material powder, further filled in the tubular casing to embed the anode). Specifically, in a cathodic protection anode device by an external power supply system that is basically composed of carbon powder), the tubular casing is electrically energized by being installed along the inner peripheral surface of the hole, if necessary. It is characterized in that it is fixedly supported in the hole by a conductive mortar wall filled in the hole outside the tubular casing via a flexible cylinder.

[Action]

The conductive mortar filled on the outside of the tubular casing does not prevent passage of anticorrosion current and does not fluidize due to water injection, so it does not flow into the tubular casing during anode replacement work. Since the well wall is firmly held, the tubular casing may be made of conductive synthetic resin in addition to metal.

The electrically conductive cylindrical body used as a mold according to need can make the thickness of the mortar uniform and can adjust this thickness appropriately.

〔Example〕

Next, an anode device for cathodic protection of the present invention will be described by way of examples with reference to the drawings.

Example 1 FIG. 1 is a schematic sectional view showing an example of the anode device according to the present invention. In this figure, the members corresponding to the respective members constituting the anode device of FIG. 3 have already been used. The same reference numerals are attached.

Of the configuration and operation of this anode device, the third one already described
The description of the parts that are the same as the structure and operation of the conventional device in the figure is omitted, and the different parts, that is, the structure and operation improved by the present invention will be described below.

In the anode device of FIG. 1, as shown in the figure, on the outside of the synthetic resin casing 2, for example, a mixture of mortar and a conductive material (for example, metal powder) or a mixture of a resin and a conductive material is used. The conductive mortar 9 is filled in. The conductive mortar 9 may be filled outside the tubular casing 2 by any method. It is convenient to inject from the inside to the outside of the casing 2. After filling the mortar 9 with the mortar 9, the anode 4 is suspended in the casing 2 and then the backfill 6 made of, for example, carbon powder is filled. This backfill 6 is the same as the inner backfill 6 in the conventional device. This conductive mortar 9
Since it suffices to be outside the electrically conductive portion of the lower portion of the tubular casing 2 ', the upper portion thereof may be filled with another kind of mortar or the like.

Since the cylindrical wall formed by such conductive mortar 9 has the same conductivity as the outer backfill 6b in the conventional device, it enables the passage of anticorrosion current and, after solidification, has sufficient rigidity and strength. Therefore, even if the conductive tube body 5 is pierced by corrosion at the time of replacing the anode, it does not flow into the casing 2 by pouring water, and firmly holds the well wall.

Embodiment 2 FIG. 2 is a schematic sectional view showing another embodiment of the present invention, in which parts similar to those of the anode device described so far are omitted.

As shown in the figure, in this anode device, a bottomed steel pipe 11 is provided along the inner peripheral surface of a cylindrical hole 1, and a tubular casing 2'is made of a synthetic resin pipe 2'located at the upper part. a
And a steel pipe 2'b connected to the lower end of the steel pipe 2'b. The outer hole of the steel pipe 2'b is filled with the conductive mortar 9 as in the first embodiment.

In this case, in order to keep the thickness of the conductive mortar 9 uniform,
It is preferable that the steel pipe 11 and the steel pipe 2'b are assembled on the ground, and in this state, they are inserted into the cylindrical hole 1 while being connected to the synthetic resin pipe 2'a, and the bottomed steel pipe 11 is a formwork. Also has the action of.

The tubular wall formed by the conductive mortar 9 also has the same properties and functions as above, and the steel pipe 11 makes the thickness of the tubular wall uniform and adjusts the thickness appropriately. You can also

In this embodiment, the electrically conductive cylinders provided inside the lower portion of the tubular casing 2'and on the inner peripheral surface of the hole 1 are made of steel pipes 2'b and 11, respectively. However, all of these members are electrically conductive. Since it suffices that the partition wall has a temporary partition wall when the anode 4 is installed, the material forming these members is not limited to metal, and may be, for example, a porous material or a conductive synthetic resin that does not hinder current flow. Needless to say.

〔The invention's effect〕

As is clear from the above description, according to the present invention, there is provided a cathodic protection device having a tubular wall having sufficient rigidity and strength without hindering the passage of anticorrosion current. When the anode is replaced, even if the conductive material filling the anode is fluidized by injecting water and then sucked, the cylindrical wall formed by the conductive mortar does not collapse, and a stable space is provided inside. Since the portion is formed and held, there is an industrially useful effect that the work that requires removal of the backfill, such as the anode replacement work, can be easily performed.

[Brief description of drawings]

1 and 2 are schematic cross-sectional views showing different embodiments of the anode device of the present invention, and FIG. 3 is a schematic cross-sectional view showing a conventional anode device. In the figure, 1 ... hole, 2,2 '... casing, 3 ... through hole, 4 ...
… Anode, 5,2′b, 11 …… Steel tube, 6,6a, 6b …… Backfill, 7 …… Conducting wire, 8 …… Rectifier 9 …… Conductive mortar, 10 …… Nozzle, A …… Corrosion resistant body.

Claims (6)

[Claims] 1. A cylindrical hole drilled at a predetermined position in the soil, a tubular casing inserted into this hole, the upper part of which has an insulating property and the remaining lower part of which has a conductive property. In a cathodic protection anode by an external power supply method, which is basically composed of a cathodic protection anode inserted in a tubular casing and a conductive material powder filled in the tubular casing so as to embed the anode. An anode device for cathodic protection by an external power supply method, wherein the tubular casing is fixedly supported in the hole by a conductive mortar filled in the hole outside the tubular casing. 2. An anode device for cathodic protection according to claim 1, wherein the tubular casing has an upper part made of an insulating tube and a lower part made of a conductive tube. . 3. The tubular casing is composed of an insulating tube body having a through hole in a lower portion and a conductive tube body fitted to an outer surface of the lower portion of the tubular body. An anode device for cathodic protection according to claim (1). 4. A cylindrical hole drilled at a predetermined position in the soil, a tubular casing inserted into this hole, the upper part of which has an insulating property and the remaining lower part of which has a conductive property, In a cathodic protection anode by an external power supply method, which is basically composed of a cathodic protection anode inserted in a tubular casing and a conductive material powder filled in the tubular casing so as to embed the anode. , The tubular casing is fixedly supported in the hole by a conductive mortar filled in the hole outside the tubular casing through an electrically conductive cylindrical body provided along the inner peripheral surface of the hole. Anode device for cathodic protection by external power supply, characterized in that 5. The anode device for cathodic protection according to claim 4, wherein the tubular casing has an upper part made of an insulating tube and a lower part made of an electrically conductive tube. . 6. The tubular casing is composed of an insulating tubular body having a through hole in the lower portion, and a conductive tubular body fitted to the outer surface of the lower portion of the tubular body. An anode device for cathodic protection according to claim (4).