JP3718615B2 - Dust collection hood for molten metal processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dust collection hood for a molten metal processing facility such as a converter and a hot metal pretreatment facility.
[0002]
[Prior art]
In equipment exposed to high-temperature gas atmospheres such as steelmaking converters and hot metal pretreatment equipment, a membrane-type cooling structure in which a number of cooling water tubes are welded in a substantially parallel state via fins (hereinafter, "Membrane panel") is used.
[0003]
[Problems to be solved by the invention]
In such a water-cooled membrane panel, there is a problem that the tube is thinned due to wear due to dust contained in the exhaust gas, or oxidative corrosion due to high-temperature gas and attached metal.
In order to prevent thinning of the tube of the above water-cooled membrane panel and prevent a decrease in service life, the inner surface exposed to high-temperature exhaust gas has a ceramic spray coating with excellent wear resistance and excellent corrosion resistance. A technique for forming a stainless steel spray coating is known. However, if these sprayed coatings are formed alone, sufficient effects cannot be obtained in facilities that require characteristics of both wear resistance and corrosion resistance.
[0004]
Therefore, a technique has been proposed in which a sprayed coating of a self-fluxing alloy having excellent wear resistance, corrosion resistance and adhesion to a base material is formed on the inner surface of the membrane panel.
In the process of forming the self-fluxed alloy spray coating on the inner surface of the membrane panel as the base material, after the thermal spraying, a fusing treatment is required in which not only the spray coating but also the base material is heated to near 1000 ° C. In such a fusing process, heat distortion is likely to occur. If the generation of this distortion is to be suppressed as much as possible, a sprayed coating of a self-fluxing alloy is not formed over the entire surface of the base material, but locally. There was no other way but to form. As a result, a part where the sprayed coating of the self-fluxing alloy is not formed remains, and this part is subject to wear and corrosion, resulting in a reduction in the panel life. Can't get.
Therefore, an object of the present invention is to provide a dust collection hood for a molten metal processing facility that solves the above-mentioned problems of the conventional technology and is excellent in wear resistance and corrosion resistance.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the inventors have arrived at the present invention having the following contents.
That is, the dust collection hood for molten metal processing equipment of the present invention is
Having a membrane panel consisting of a cooling water tube and fins, and providing a spray coating of a self-fluxing alloy on the surface of the membrane panel that comes into contact with the exhaust gas, and a reinforcing brace fixed to the surface on the anti-spraying side It is characterized by.
[0006]
According to such a configuration, it is possible to provide a thermal spray coating on the entire surface of the required construction surface while minimizing distortion due to the heat of fusing, thereby causing wear due to dust, high temperature gas, adhesion metal, etc. As a result, it is possible to effectively prevent the oxidative corrosion due to the above, and thus it is possible to prevent the life of the panel from being reduced on average.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1: has shown the outline of one Embodiment of the exhaust gas dust collection hood for hot metal pretreatment as an example of the dust collection hood for molten metal processing facilities concerning this invention.
The dust collecting hood 10 constitutes a dust collecting device for collecting exhaust gas generated by hot metal pretreatment in a hot metal transport container 12 (hereinafter referred to as “topy car”). The lower hood 16 is opened at a position spaced apart upward, and effectively collects the exhaust gas generated by the hot metal pretreatment. The lower hood 16 is formed in the upper hood 18 at the center. The dust collection duct 20 is guided to the exhaust gas treatment facility (not shown).
[0008]
In the upper part of the opening 14 of the topped car 12, since the temperature of the exhaust gas being processed is a high temperature atmosphere of about 1500 ° C., the lower hood 16 and a part of the dust collecting panel 10 above it, that is, the upper hood As shown in FIGS. 2 and 3, the inner surface of 18 is provided with a membrane panel 26 composed of a number of cooling tubes 22 and fins 24.
Such a cooling membrane panel 26 has a tube-fin welding structure in which a large number of cooling tubes 22 are arranged adjacent to each other, and fins 24 are welded between the tubes 22, and each tube 22 has a water supply header. The cooling water is supplied from 28 and is recirculated from the drainage header 30 through a circulation pump (not shown), and is used for the purpose of efficiently cooling a wide area inside the dust collection hood 10.
[0009]
In the exhaust gas dust collecting hood 10 for hot metal pretreatment according to the present invention, as shown in FIG. 3, a spray coating 32 of a self-fluxing alloy is formed over the entire surface of the membrane panel 26 in contact with the exhaust gas. ing.
This self-fluxing alloy is a nickel-base alloy or cobalt-base alloy as specified in JIS H 8303 containing a flux component such as B or Si. After forming an alloy film by spraying on a surface on the side in contact with the exhaust gas of 26 under a certain condition capable of forming a semi-molten film, a fusing treatment is performed under a temperature condition of 1000 to 1100 ° C. The thermal spray coating 32 having high adhesion to the panel 26 is formed.
The thickness of the spray coating 32 of the self-fluxing alloy is desirably 0.5 to 2.0 mm, and more preferably 0.5 to 1.0 mm. The reason is to reduce internal residual stress (strain generation).
[0010]
On the other hand, a reinforcing brace 34 having a frame structure as shown in FIG. The reinforcing brace 34 is fixed in advance to the surface of the membrane panel 26 that does not come into contact with the exhaust gas so that the membrane panel 26 is not distorted by heat in the fusing process for forming the spray coating 32 of the self-fluxing alloy. The
The reinforcing brace 34 is formed using a material such as H-shaped steel, for example, and is fixed to the membrane panel 26 by a method such as welding.
[0011]
【The invention's effect】
As described above, according to the dust collection hood for molten metal processing equipment of the present invention, distortion due to fusing heat can be minimized, oxidation due to dust, high temperature gas, and adhesion metal. Since corrosion can be effectively prevented, it is possible to prevent a decrease in life on average in the entire membrane panel.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a dust collection hood for a molten metal processing facility of the present invention.
FIG. 2 is a schematic plan view and side view of a membrane panel according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a membrane panel and a self-fluxing alloy spray coating formed thereon according to an embodiment of the present invention.
FIG. 4 is a schematic perspective view showing a membrane panel and a reinforcing brace fixed on the membrane panel in an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Dust collection hood 12 Hot metal transport container 14 Opening part 16 Lower hood 18 Upper hood 20 Dust collection duct 22 Tube 24 Fin 26 Membrane panel 32 Self-fluxing alloy spray coating 34 Reinforcement brace

Claims (1)

In a dust collection hood for a molten metal processing facility having a membrane panel composed of a cooling water tube and fins,
A dust collection hood for a molten metal processing facility, wherein a spray coating of a self-fluxing alloy is provided on a surface of the membrane panel that comes into contact with exhaust gas, and a reinforcing brace is fixed to a surface on the anti-spraying side.

Images