JP2890785B2 - Ballast tank corrosion protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ballast in which a water film is formed on an inner wall of a tank and a sacrificial anode when a ballast tank is empty or when ballast water is half loaded, and corrosion is prevented by a galvanic anode. The present invention relates to a method for preventing corrosion of a tank.

[Prior Art] A tank for loading a fluid partitioned in a ship includes:
Since the inner wall of the tank is corroded by the loaded fluid, various anticorrosion methods are used.

As an example of the anticorrosion method, a method using a coating, a method using a galvanic anode, or a combination of both are common.

On the other hand, in a dedicated ballast tank that loads and discharges ballast water to adjust the ups and downs (draft, trim, heel, etc.) of the ship, even when the tank is empty, the tank inner wall is oxidized by oxygen in the air. To prevent corrosion, a method of applying a rust-preventive paint to prevent corrosion is used, and in order to complement the corrosion, a method of preventing corrosion by using a galvanic anode method is used.

This galvanic anode method uses Zn, Al on the inner wall of the ballast tank.
Alternatively, a large number of sacrificial anode members formed of these alloys are attached, and a corrosion current is caused to flow from the sacrificial anode member to the inner wall of the tank using ballast water as a medium so as to prevent the inner wall of the tank from being corroded.

[Problems to be Solved by the Invention] By the way, in the above-mentioned galvanic anode method, since a corrosion-resistant current is made to flow using ballast water as a medium, it is not suitable for corrosion prevention in a place where there is no ballast water. . Therefore, in order to prevent corrosion of the inner wall of the ballast tank when the tank is empty, it is necessary to apply a plurality of layers of rust preventive paint to the inner wall of the tank.

Recently, there has been an enthusiasm to build a tanker with a double-shell structure.If the tanker has a double-shell structure, the volume of the ballast tank will increase, and the amount of coating inside the tank will be dramatically greater than that of a conventional tanker. There is a problem that increases.

The present invention has been made in order to solve the above-mentioned problem, and an object of the present invention is to effectively perform galvanic anodic corrosion prevention even when the ballast tank is empty, and to reduce the amount of coating. To provide a method for preventing corrosion of a ballast tank.

Means for Solving the Problems In order to solve the above object, the present invention relates to a method for mounting a plurality of sacrificial anode members in a ballast tank partitioned in a hull and corroding the ballast tank. A sprinkler pipe having a number of sprinkler nozzles is arranged along the inner wall of the tank, and when the ballast tank is empty or when ballast water is half loaded, the sprinkler nozzle passes through the sprinkler nozzle and the tank inner wall and the sacrificial anode. Seawater is sprayed and sprayed on the member to form a water film, and galvanic anodic corrosion is performed.

[Operation] According to the above configuration, when ballast water is fully loaded in the ballast tank, a corrosion-resistant current flows from the sacrificial anode member to the tank inner wall using the ballast water as a medium, and thereby the tank inner wall is corroded.

In addition, when the ballast tank is empty or when ballast water is half loaded, seawater is sprayed from the watering nozzle onto the tank inner wall and the sacrificial anode member via the watering pipe to form a water film.
As a result, an anticorrosion current flows from the sacrificial anode member to the inner wall of the tank using the water film as a medium, thereby anticorrosing the inner wall of the tank.

In this way, the inner wall of the tank can be protected by galvanic anodic corrosion even when the ballast tank is fully loaded, not to mention when it is empty or partially loaded, reducing the amount of paint applied inside the tank. And the amount of painting work can be greatly reduced.

Embodiment An embodiment of the present invention will be described with reference to the accompanying drawings.

1 and 2 show one embodiment of a hull to which the method of the present invention is adopted.

In the figure, reference numeral 1 denotes a ballast tank, and a ballast tank 1 includes an inner wall 2 such as a hull outer panel, a vertical and horizontal bulkhead, a deck and a double bottom.
The inner wall 2 is provided with an inner member 3 for reinforcing the inner wall 2. These inner wall 2 and inner member 3
Are provided with a large number of sacrificial anode members 4 formed of Zn, Al, an alloy thereof, or the like for corrosion protection with a galvanic anode.

In the ballast tank 1, a large number of watering pipes 5 are provided along the inner wall 2, and these watering pipes 5
Is connected to a water supply pipe 6 for supplying seawater to the seawater. Water pipe 6
As shown in the figure, is disposed along the ship's length on a hull deck 7 that partitions the ballast tank 1, and one end thereof is connected to a water supply pump (not shown) that suctions and supplies seawater.

Each sprinkler pipe 5 includes an inner wall 2, an inner member 3, and a sacrificial anode member 4.
A large number of water spray nozzles 8 are provided for spraying and spraying seawater supplied toward the tank. Seawater sprayed and sprayed from these water spray nozzles 8 forms a water film on the tank inner wall 2, the inner member 3, and the sacrificial anode member 4. It is supposed to.

 Next, the method of the present invention will be described using the above embodiment.

When the ballast tank 1 is full of ballast water, corrosion-resistant current flows from the sacrificial anode member 4 to the inner wall 2 and the inner member 3 using the ballast water as a medium, and the inner wall 2 and the inner member 3 are corroded.

Further, when the ballast tank 1 is empty or when ballast water is half loaded, seawater is sucked by a water supply pump (not shown) and supplied to the water supply pipe 6, and the seawater is sprayed from the water spray nozzle 8 through the water spray nozzle 8 to the inner wall 2, 2. A water film is formed by spraying and spraying water on the inner member 3 and the sacrificial anode member 4.

As a result, corrosion current flows from the sacrificial anode member 4 to the inner wall 2 and the inner member 3 using the water film as a medium, and the inner wall 2 and the inner member 3 are corroded.

As described above, the inner wall 2 and the interior 3 of the ballast tank 1 are corroded by the galvanic anode not only when the ballast tank is fully loaded, but also when the ballast tank is fully loaded or half loaded, so that the ballast tank 1 is coated. The amount of paint such as rust preventive paint can be reduced, and the amount of painting work can be greatly reduced.

Although the drawings adopted in the above embodiments show a hull having a double shell structure, the method may be applied to a ballast tank of a normal ship in which the hull is not formed in a double shell. Needless to say.

[Effects of the Invention] According to the present invention, even when the ballast tank is empty and the ballast water is half loaded, the inner wall of the tank can be protected from corrosion by the galvanic anode. It has excellent effects such as the amount of paint to be applied and the amount of painting work can be greatly reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a transverse sectional view showing an embodiment of a hull adopting the method of the present invention, and FIG. 2 is a perspective view showing a part thereof. In the figure, 1 is a ballast tank, 2 is a tank inner wall, 4 is a sacrificial anode member, 5 is a water spray pipe, and 8 is a water spray nozzle.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C23F 13 / 00,15 / 00 B63B 59 / 00,59 / 04

Claims (1)

(57) [Claims] In a method for mounting a plurality of sacrificial anode members in a ballast tank partitioned and formed in a hull, the ballast tank is corroded. In the method, a water pipe having a plurality of water nozzles is provided along an inner wall of the ballast tank. When the ballast tank is empty or when ballast water is half loaded, seawater is sprayed and sprayed from the watering nozzle onto the tank inner wall and the sacrificial anode member through the watering pipe to form a water film. An anticorrosion method for a ballast tank, which is provided with electroanode corrosion protection.