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NIPPON CORROSION ENGG

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Nippon Corrosion Industry Co., Ltd. has a rich track record of cathodic protection for over half a century.

NIPPON protect important infrastructure such as electricity / gas / water related facilities, road / railway related facilities, marine / port facilities, etc.

There are two types of cathodic protection methods: cathodic protection (cathodic protection) and anodic protection (anodic protection), but the anodic protection is used in a special environment and there are no examples. On the other hand, the cathodic protection method is widely used for ships, harbor facilities, buried piping, etc., so the term “cathodic protection” refers to the cathodic protection method.
The target is metals that exist in electrolytes (substances that conduct electricity such as water, soil, concrete, etc.). In addition to steel, there are aluminum alloys, stainless steel, lead, and copper alloys.

There are a wide variety of ships such as tankers, ore ships, container ships, passenger ships and LNG ships. The anti-corrosion method is indispensable for preventing corrosion of heat exchangers.
In order to prevent marine organisms from adhering to the seawater piping and heat exchangers and blocking the seawater piping system, an antifouling device that electrolyzes seawater and generates hypochlorous acid and a copper electrode are installed. An antifouling device that generates copper ions by electrolysis is installed.

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Power Supply

Insoluble Electrode

Cathodic protection

There are two methods of cathodic protection: “external power supply method” and “galvanic anode method”.

External power supply method

“SEAPAC” (“Seapack”: hull skin automatic corrosion protection device) is an automatic constant potential external power supply for hull skin. Nippon Corrosion has a track record of over 2,000 ships.
“SEAPAC” automatically reduces and optimizes the anti-corrosion condition of the hull, reducing the work burden on the crew and dramatically improving the ship’s operating rate.

Galvanic anode method

Stern that is corroded by Allanode

Nippon Corrosion offers aluminum alloy anode “Aranode” and zinc alloy anode “Ginnode” for hull skins and ballast tanks.

Silvers (propeller shaft grounding device)

When the propeller shaft rotates, it is insulated from the hull by the lubricating oil film, so the cathodic protection device attached to the hull will not be able to protect the propeller.
“Silvers” is a device that electrically connects the hull and propeller shaft to achieve anti-corrosion of the propeller and prevention of spark erosion of the engine, and is installed in many ships built in Japan.
A monitoring instrument is also available to monitor the propeller shaft grounding effect of “Silver”.

Silvers

Monitoring Meter

Iron film formation DEFECON

“DEFECON” is a device that generates iron ions by electrolyzing an iron anode and forms an iron oxide film to prevent corrosion. Since it is an electrolytic type, the iron ion concentration can be freely controlled by adjusting the current, and the optimum anticorrosion state can be easily maintained.

Power plant / factory equipment

A wide variety of equipment is installed in power plants and various factories to take seawater and industrial water and use it as cooling water. The anticorrosion method is indispensable for the corrosion prevention of these facilities and equipment.
In addition, in order to prevent marine organisms from breeding and adhering to the facilities and equipment in the seawater line and blocking the inside of the line, an antifouling device that electrolyzes seawater and generates hypochlorous acid (adhesion of marine organisms) Prevention device) is installed.
Nippon Corrosion offers the best anti-corrosion and anti-fouling methods based on a meticulous design supported by a wealth of experience.

Cathodic protection

Seawater intake pipe, destination machine.

Platinum titanium electrode installed in intake pipe

Since the seawater intake pipe and the water intake destination machine are installed in seawater, it is necessary to protect the inner and outer surfaces.
For external corrosion protection, the current-carrying anode method or external power supply method is adopted after considering the conditions such as the scale of the equipment and the corrosion-proof construction environment.
Aluminum alloy anode “Aranode” and zinc alloy anode “Ginnode” are used as the galvanic anode, and MMO (metal oxide coating) electrode and platinum titanium electrode are mainly used as the external power source electrode.

Dust removal device (screen), strainer, shell removal device

Since dust removal equipment, strainers, and shell removal equipment are generally composed of a stainless steel body and a steel support material, it is easy for two-metal contact corrosion (galvanic corrosion) to occur between the two metals. Some have moving parts such as rotary screens and open / close strainers. The anti-corrosion of these devices adopts the galvanic anode method or the external power supply method, taking into consideration the size and function of the equipment and the influence on the adjacent equipment. “Aranode” and “Ginnode” are available for the galvanic anode. In addition, the automatic constant potential method is often used in the external power supply method, and MMO (metal oxide coating) electrodes and platinum titanium electrodes are mainly used as electrodes.

Allanode attached to the screen body

Electrode guide pipe installed on the side wall of the channel

Circulating water pump

Inside the circulating water pump, the flow rate of seawater is as high as several meters / second, so the inside of the pump is exposed to a severe corrosive environment. In particular, around the impeller rotating at high speed, corrosion called cavitation due to intense turbulence occurs. Nippon Corrosion has a proven track record in preventing corrosion in such harsh corrosive environments. An external power supply system is mainly used for corrosion prevention of circulating water pumps, and MMO (metal oxide coating) electrodes and platinum titanium electrodes are mainly used for the electrodes.

Platinum titanium electrode installed on circulating water pump

Circulating water pipe inner surface

Allanode installed on the inner surface of the circulating water pipe

Seawater is constantly moving at about 2 meters / second on the inner surface of the circulating water pipe, creating a severely corrosive environment. In addition, stainless steel strainers and shell removal devices are installed in the middle of the circulation path, and condensers with copper alloys and titanium alloys are installed at the ends, making it susceptible to contact with different metals (galvanic corrosion). In the environment.
Nippon Corrosion Co., Ltd. provides the most suitable anti-corrosion method based on our abundant track record, accurately grasping the influence from such surrounding devices and equipment.
“Aranode” or “Ginnode” is used for the galvanic anode, and MMO (metal oxide coating) and platinum titanium electrodes are mainly used for the external power supply type electrodes.

Condenser

In the condenser, the water chamber is generally made of steel, and the cooling pipe and tube plate are made of copper alloy or titanium alloy, or a combination of these. However, excessive corrosion protection of titanium alloys can cause hydrogen embrittlement. Accurate potential control is required to properly protect these condensers.
Nippon Corrosion Co., Ltd. offers the best anti-corrosion technology with a power supply unit that incorporates a reference electrode that detects the potential and a high-performance constant-potential circuit. We have also developed a corrosion protection device that has both functions of electric corrosion protection and iron ion generation, consisting of a bipolar iron electrode and a constant-potential / constant-current control power supply device. Provided.

Bipolar iron electrode installed in condenser water chamber

Constant potential / constant current control power supply

Heat exchanger

Heat exchangers are widely used for various applications such as steam condensation, high-temperature water cooling, and heat absorption during chemical reaction processes, but all use seawater and industrial water as cooling water. Tube sheets and cooling pipes are exposed to severe corrosive environments.
The anticorrosion method is indispensable for such heat exchangers. “Aranode” or “Ginnode” is used for the galvanic anode, and MMO (metal oxide coating) electrode and platinum titanium electrode are mainly used for the external power supply type electrode.

Heat exchanger protected against corrosion by CPZ

Gas cooler with MMO electrode

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