JPH018878Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electric furnace generated gas combustion tower for completely combusting incompletely combusted gas sucked from an electric furnace. This invention relates to an electric furnace gas combustion tower equipped with a corrosion-resistant structure that prevents corrosion by cooling water.

The electric furnace gas combustion tower is designed to completely burn the suction gas, as it contains combustible gases such as CO, which poses a risk of explosion if introduced directly into the dust collector. Electric furnace gas combustion towers generally have a double structure consisting of an outer cylinder and an inner cylinder, and suction gas is introduced into the inner cylinder through an intake port provided at the top to completely burn the incompletely combusted gas in the suction gas. , is discharged from the exhaust port installed at the bottom and sent to the dust collector via the cooling tower.The combustion tower itself burns incompletely combusted gas inside and becomes high temperature, so to prevent the combustion tower from overheating. Cooling water is circulated between the outer cylinder and the inner cylinder.

However, even in a combustion tower made of steel plates with a thickness of about 12 mm, when incompletely combusted gas is combusted, the temperature inside the tower reaches 1300-1400℃, and the flow velocity of the combustion gas reaches 150 m/sec. Therefore, the temperature of the iron plate that makes up the inner cylinder also rises. The temperature is highest on the inside of the inner cylinder, which is directly exposed to the combustion gas, but the iron plate surface is relatively flat with only 2 to 3 mm of unevenness. The temperature of the cooling water on the surface of the iron plate is approximately 180℃, which causes it to boil, and the cooling water absorbs oxygen in the circulation channel, and local corrosion is accelerated by the oxygen dissolved in the cooling water. The surface of the steel plate on the side where the cooling water flows through the cylinder, especially the front steel plate of the suction gas inlet, has become severely corroded and has large irregularities, and even the 12mm thick steel plate will have holes in it within a year or two, causing water to leak into the inner cylinder. It takes a lot of effort and time to repair it. The present invention was developed in view of the above-mentioned drawbacks, and a corrosion-resistant structure that contains oxygen and has sufficient corrosion resistance against boiling cooling water is applied to the surface of the iron plate on the inner cylinder cooling water distribution side, which has a particularly high corrosion rate. In order to achieve this, the inventor investigated various anti-corrosion coatings and found that it is difficult to thermally spray aluminum directly onto a steel plate, so austenitic stainless steel was thermally sprayed as a base to form a coating, and then aluminum was applied on top of it. We discovered that the most superior anti-corrosion coating was a thermal sprayed aluminum coating, and since the surface of the aluminum sprayed coating had some irregularities, epoxy coating was applied as needed, greatly extending the durability life of the combustion tower. This is what I did.

The configuration will be explained below based on the drawings of one embodiment.

Reference numeral 1 designates a combustion tower for sucking gas generated from an electric furnace 2 through a suction port provided in a furnace lid 3 through a gas introduction pipe 4, and completely combusting incompletely combusted gas in the suction gas.

The combustion tower 1 has an intake port 5 at the top for introducing suction gas.
It has an exhaust port 6 at the bottom for discharging combustion gas, and its main body has a double structure with an outer cylinder 7 and an inner cylinder 8 made of iron plates, and the suction gas is discharged into the inner cylinder 8. It circulates and burns, and the outer cylinder 7
It has a cooling structure that allows cooling water to flow between the inner cylinder 8 and the inner cylinder 8.

9 and 10 are the anti-corrosion coatings formed after removing rust from the iron plate surface on the cooling water flow side of the inner cylinder 7 and applying shotplast treatment. 9 is the SUS304 austenitic stainless steel coating that is coated as a base, and 10 is the coating on top of it. The thickness of the austenitic stainless steel base is 0.05 mm, and the thickness of aluminum is 0.15 mm.

The thickness of this coating must be 0.03 mm for austenitic stainless steel in order to have sufficient corrosion resistance.
It is desirable that the aluminum coating has a thickness of 0.10 mm or more, and if the thickness is increased more than necessary, the durability will not improve much.

As mentioned above, in order to prevent corrosion caused by the boiling water that contains oxygen during the cooling water circulation, this invention uses austenitic stainless steel as a base material to coat the surface of the iron plate on the inner cylinder cooling water circulation side as an anticorrosion coating. By coating it with aluminum and forming an aluminum coating on it, the amount of corrosion is extremely small even in the harsh environments mentioned above, and even after 6 months, almost no corrosion is observed, preventing water leakage. There is no need to worry, and the life of the combustion tower can be greatly extended.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a combustion tower equipped with the corrosion-resistant structure of the present invention for completely burning gas discharged from an electric furnace, and FIG. 2 is a vertical sectional view of an inner cylinder. 1... combustion tower, 5... intake port, 6... exhaust port,
7... Outer cylinder, 8... Inner cylinder, 9... Austenitic stainless steel coating, 10... Aluminum coating.

Claims (1)

[Scope of utility model registration request] The gas generated in the furnace is sucked through the suction port drilled in the lid of the electric furnace, and the gas is completely combusted.The upper part has an intake port for introducing the suction gas, and the lower part has an exhaust port for discharging the burned intake gas. It has a double structure with an outer cylinder and an inner cylinder, and the suction gas flows into the inner cylinder from the intake port and is discharged from the exhaust port, and cooling water flows between the outer cylinder and the inner cylinder. In a closed combustion tower having a cooling structure, an austenitic stainless steel coating of 0.03 to 0.30 mm is formed as a base on the cooling water flow side of the iron plate forming the inner cylinder by thermal spraying, and a 0.10 to 0.50 mm of austenitic stainless steel coating is formed on the base by thermal spraying. An electric furnace generated gas combustion tower having a corrosion-resistant structure characterized by an aluminum coating formed by thermal spraying.