JPH0718475A - Method for installing galvanic anode to underwater steel structure and anode panel used in this method - Google Patents

Abstract

PURPOSE:To easily mount a galvanic anode for the electrolytic protection to an under water structure by sinking an anode panel formed by previously mounting many gal vanic anodes to a conductive frame body into water and welding the arms projecting from this frame body to the underwater structure in the water. CONSTITUTION:Both ends of arbors of many pieces of the galvanic anode 3 are previously welded and fixed on the ground to the frame body 2 built by assembling vertical frames 2a and horizontal frames 2b consisting of conductive materials, such as angle pipes and concrete weights 6a are mounted at the bottom end thereof. After this anode panel 1a is sunk near the underwater structure S, the arms 4 in common use for energization mounted horizontally on the frame body 2 and arm steels 5 for energization are welded 9 in the water to the steel structure S. The steel structure S and the galvanic anodes 3 are held energized to the arms 4, 5 by the frame body 2 in the water, by which the steel structure S is electrolytically protected. Only the welding of the arms of the anode panel is merely necessitated for the welding operation in the water and, therefore, the underwater operation is easily and safely executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of installing a galvanic anode used for cathodic protection of a steel structure in water and an anode panel used in the method.

[0002]

2. Description of the Related Art For example, a conventional galvanic anticorrosion method using a galvanic anode made of aluminum, zinc, magnesium, or an alloy of aluminum, zinc, magnesium, or an alloy thereof has been used as the anticorrosion method for underwater parts of steel structures such as steel sheet pile quays, floating steel structures, and water intake facilities. Widely practiced from. When attaching these galvanic anodes to the underwater steel structure, the diver attached the both ends of the core metal of the galvanic anode directly to the steel structure one by one by the underwater welding operation. Also, when replacing the anode, a diver dives in the same manner, and the welding part is removed one by one.

[0003]

However, in a deep sea, in a place where waves or tides are intense, a diving person can work underwater for about 40 minutes each time, and a harbor with a shallow seabed close to the land. It takes about 1 to 2 hours at the facility.
Therefore, in the underwater mounting work of the anode under such a condition, the number of mounting is limited and it is not efficient.

Therefore, it is an object of the present invention to replace most of the underwater welding work with ground work so that the submerged steel structure can be installed safely, reliably and in a short construction period. It is to provide a method and an anode panel used in the method.

[0005]

In order to achieve the above-mentioned object, the present invention is a method of installing a galvanic anode for cathodic protection on a submerged steel structure, wherein a large number of galvanic electrodes are preliminarily provided on a conductive frame. It is characterized in that an anode panel provided with an electric anode is submerged in a predetermined position, and then the tip of a arm bar protruding from the frame is underwater-welded to a steel structure.

The first anode panel of the present invention is a frame body assembled from a conductive material such as a pipe, a large number of galvanic anodes attached to the frame body, and projectingly provided on one side of the frame body. 2
It is characterized by comprising: ~ 4 electricity-carrying steel bars; and a weight which is fixed to the lower end of the frame body and which supports the panel so as to be self-supporting.

Further, the second anode panel includes a frame body assembled from a conductive material such as a pipe, a large number of galvanic anodes attached to the frame body, and two projections provided on one side of the frame body. ~ 4
The present invention is characterized by comprising a current carrying arm steel and a weight which is fixed to the lower end of the frame body and supports the panel so as to be tiltable by its own weight. It is preferable that the first anode panel and the second anode panel are made of anticorrosive materials such as coating.

[0008]

In the installation method of the present invention, a large number of galvanic anodes are previously attached to the panel by ground work, and only the arm part of the panel is underwater-welded to the steel structure at the time of sunk work. The number of anodes installed will increase significantly.

When the first anode panel is submerged in water, it stands upright and the second anode panel leans against its own weight and leans against the steel structure. Therefore, both are easily mounted. be able to.

[0010]

1 to 4 show an embodiment of a first anode panel 1a which is a self-standing submerged type, in which a frame body 2 vertically and horizontally assembled with a conductive material such as an angle pipe or a channel material is used. , Several to several tens of galvanic anodes 3 are attached in advance.

In the embodiment shown in FIGS. 1 and 2, a galvanic anode 3 is vertically installed between a plurality of horizontal frames 2b of the frame body 2. That is, both ends of the core metal of the anode 3 are welded to the upper and lower horizontal frames 2b, respectively. Further, in the embodiment of FIGS. 3 and 4,
The galvanic anode 3 is horizontally attached to the upper surface of each horizontal frame 2b.

On the uppermost horizontal frame 2b, there are two to four arm wires 4 which also function as current-carrying points in a direction orthogonal to the horizontal frame 2b and horizontally.
Similarly, a plurality of current-carrying steel bars 5 are similarly provided on the horizontal frame 2b and a lower horizontal frame 2b, if necessary.

At the lower end of the vertical frame 2a, a weight 6a of concrete or the like having a rectangular cross section is fixed so that the panel 1a can stand upright.

The above-mentioned anode panel 1a, which has been manufactured by ground work in a factory in advance, is hung by a crane or the like to be submerged in a predetermined position near the underwater steel structure S to be self-sustainingly stable. The tip of the gold 4 is fixed to the steel structure S by underwater welding 9. As a result, the steel structure S and the anode 3 are connected to the arms 4, 5
And, it is energized through the frame body 2 to be galvanically protected.

Next, FIG. 5 to FIG. 9 are the second type, which is a sinking type.
FIG. 3 shows an example of the anode panel 1b of the steel structure S which is tilted by its own weight when immersed in water.
It is designed to be leaned against. That is, for that purpose, the lower surface of the weight 6b is formed in a substantially arcuate shape in cross section, and the lower end of the vertical frame 2a is fixed at a position displaced from the center of the weight 6b to the steel structure S side (FIG. 5, FIG. 7). Further, as shown in FIG. 9, the lower surface of the weight 6c is provided with leg portions 7 having different lengths,
It may be formed stepwise by 8.

In this panel 1b, the lengths of the current-carrying arm / bracket 4 and the current-carrying arm steel 5 attached as necessary are set so that the lower the length, the longer.
Other configurations are similar to those of the self-standing anode panel 1a, and FIGS. 5 and 6 correspond to FIGS. 1 and 2, and FIGS. 7 and 8 correspond to FIGS. 3 and 4, respectively.

[0017]

As described above, according to the present invention, a large number of galvanic anodes are previously attached to a panel by ground work, and only the arm part of the panel is underwater-welded to the steel structure when the panel is sunk. The number of anodes installed per unit time will increase dramatically. Therefore, the galvanic anode can be installed safely, reliably, and in a short period of time even in an underwater steel structure in an environment where the deep sea, waves, or tidal currents are severe. Further, since the replacement work of the galvanic anode can be performed for each panel, the efficiency is greatly improved.

[Brief description of drawings]

FIG. 1 is a side view showing an installed state of an embodiment of a first anode panel according to the present invention.

2 is a front view of the panel of FIG. 1. FIG.

FIG. 3 is a side view showing an installed state of another embodiment of the first panel.

FIG. 4 is a front view of the panel of FIG.

FIG. 5 is a side view showing an installed state of an embodiment of a second anode panel.

FIG. 6 is a front view of the panel of FIG.

FIG. 7 is a side view showing an installed state of another embodiment of the second panel.

FIG. 8 is a front view of the panel of FIG.

FIG. 9 is a side view of an installed state showing a modified example of the weight on the second panel.

[Explanation of symbols]

 S Underwater steel structure 1a, 1b Anode panel 2 Frame 3 Galvanic anode 4 Arms 5 Current-carrying steel rods 6a, 6b, 6c Weight 9 Welding

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[Procedure amendment]

[Submission date] October 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

The first anode panel of the present invention is a frame body assembled from a conductive material such as a pipe, a large number of galvanic anodes attached to the frame body, and projectingly provided on one side of the frame body. 2
It is characterized by comprising: ~ 4 current-carrying steel bars; and a structure fixed to the lower end of the frame to support the panel in a self-supporting manner.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

In the installation method of the present invention, a large number of galvanic anodes are preliminarily attached to the panel by ground work, and when submerging, only the arm part of the panel or an electric wire or the like is interposed between the galvanic anode and the steel structure in the air or underwater. Therefore, the number of anodes installed per unit time is significantly increased.

Claims (3)

[Claims] 1. A method of installing a galvanic anode for cathodic protection on a submerged steel structure, comprising submerging an anode panel comprising a large number of galvanic anodes attached to a conductive frame in advance, and then substituting the anode panel in a predetermined position. A method for installing a galvanic anode on a submerged steel structure, characterized in that the tip of the arm protruding from the frame is welded underwater to the steel structure. 2. A frame body assembled from an electrically conductive material such as a pipe, a large number of galvanic anodes attached to the frame body, a current-carrying point / arm arm protruding from one side of the frame body, An anode panel, comprising: a weight fixed to a lower end of a frame body and supporting the panel in a self-supporting manner. 3. A frame body assembled from an electrically conductive material such as a pipe, a large number of galvanic anodes attached to the frame body, a current-carrying point / arm arm protruding from one side of the frame body, An anode panel, comprising: a weight fixed to a lower end of a frame body and supporting the panel so as to be tiltable by its own weight.