KR102057233B1 - Enamel composition for preventing corrosion and anti-fouling of an element of a gas gas heater and a gas air heater for a heat exchanger and enamel coating method thereof - Google Patents

Abstract

The present invention relates to an enamel composition for providing anti-fouling effect and preventing corrosion of an element for a gas air heater (GAH) and a gas gas heater (GGH) of a power plant and an enamel coating method using the same. Specifically, the enamel composition for providing anti-fouling effect and preventing corrosion of an element for a GAH and a GGH of a power plant improves thermal resistance, durability, and oxidation resistance and prevents corrosion of a heat exchange element in a GGH and a GAH used for equipment such as a heat exchanger of a power plant. The enamel composition for providing anti-fouling effect and preventing corrosion of an element for a GAH and a GGH of a power plant is to reduce excessive costs consumed for equipment replacement and maintenance. The enamel composition for providing anti-fouling effect and preventing corrosion of an element for a GAH and a GGH of a power plant is composed of: 8-18 wt% of a complex compound of acetic acid and nickel, for preventing the formation of a blow hole on the surface of coating; 80-90 wt% of powder clay; and 1-3 wt% of additives in which silicate and zirconia oxide are mixed, to improve corrosion resistance and the thermal resistance.

Description

Enamel glaze composition for corrosion protection and anti-fouling effect of power plant GGH and GAH element and enamel coating method using the same A HEAT EXCHANGER AND ENAMEL COATING METHOD THEREOF}

The present invention relates to an enamel glaze composition and an enamel coating method using the same, and more particularly, it is used in the case of performing an enamel coating on the surface of a metal product, a gas gas heater (GGH) and a gas air heater (GAH) for a power plant. The present invention relates to an enamel glaze composition and an enamel coating method using the same to facilitate the formation of an enamel coating layer for corrosion protection and anti-fouling effect of ELEMENT.

Recently, in the electricity production of thermal power plants, the use of relatively low quality coal is increasing in order to reduce costs, and when power consumption increases in a short time, the thermal power plant operates according to the threshold, and thus the thermal power plant The load on the internal plant may increase. Therefore, there is an increasing demand for increased durability of thermal power plant internal facilities.

In addition, the flue gas contains various oxides, such as nitrogen oxides, sulfur oxides, chlorine and fluorine oxides, as well as dust / ash, which are highly corrosive.

In the internal facilities of thermal power plants, APH (Air Preheater) has a relatively high temperature, which causes damage due to thermal shock and abrasion due to high-speed coal dust than damage due to sulfuric acid corrosion. In the case of GGH (Gas Gas Heater) among the internal facilities of the thermal power plant, the gas generated from the desulfurization process is preheated to a gas temperature that can scatter the smoke out of the stack to the atmosphere. The damage caused by the low temperature corrosion of sulfuric acid corrosion is mainly caused by the corrosion of the equipment, clogging of sediment, etc. is a situation that the cost loss due to the shutdown and maintenance of the entire plant.

The most common preventive measures against such corrosion include a method of changing the material of an element. That is, the corrosion resistance can be improved by changing the composition of the metal material. For example, there are cases of improvement of corrosion resistance of STS316 made by adding 2 to 3% of Mo to STS304, and also super stainless steel having better corrosion resistance than super alloy or titanium. Although such a new material is not easy to develop, the developed material is not practical because it is out of the range that can be easily used in the industry in terms of cost.

Accordingly, in recent years, an enamel coating may be applied to a thermal element of a low temperature layer in a thermal element of APH formed of a three-layer temperature layer. In addition, enamel coating is mainly applied to the thermal element of GGH.

Enamel, a glassy-metal compound fired at high temperature by glass coating on various kinds of metal surfaces, shares the special properties of metal and nonmetal, which is characterized by the chemical, physical and aesthetic sensitivity of glass and the strength and durability of metal. By sharing and complementing their characteristics, the Heat Recovery Steam Generator (HRSG) and Gas Gas Heater (GGH) for power plants are easily corroded by being exposed to complex shapes and high temperatures and strong acids. The application of enamel coating is being considered as the development of glaze which is strengthened.

However, such a conventional corrosion prevention method is not only effective, but excessively expensive, and does not meet the conditions of heat resistance, durability, oxidation resistance, etc. for power plant equipment, which makes it difficult to replace and maintain equipment. It is true.

In addition, when using the power plant heat exchanger continuously, there is a problem that the heat exchange effect is reduced by the accumulation of sediment and the like inside the fixed.

In Korean Patent Laid-Open Publication No. 10-2003-0061635 (name of the invention: an enamel composition for building materials and a method for producing an improved enamel construction material using the same), 29 to 35% of silicon dioxide (SiO ₂ ) and lead oxide (PbO ₂ ) 30 to 35%, sodium oxide (Na ₂ O) 10 to 25%, titanium (TiO ₂ ) 5 to 15%, antimony oxide (Sb ₂ O ₃ ) 0.2 to 1%, boron oxide (B ₂ O ₃ ) 0.2 to 1% of the mixture is melted, the melt is quenched to form frit, and the formed frit is pulverized to mix frit and water in a ratio of 4: 6, with 2-5% sodium silicate (Na ₂ SiO ₂ ) An enamel composition for building materials is disclosed by adding and mixing 3 to 7% of rica, boric acid (H ₃ BO ₃ ) (B ₂ O ₃ ), and 0.3 to 0.7% of methyl alcohol.

Republic of Korea Patent Publication No. 10-2003-0061635

An object of the present invention for solving the above problems, by performing the enamel coating on the surface of the equipment used in the heat exchanger for power plants, to increase the effects of heat resistance, acid resistance, hydrophilicity, etc., as well as to increase the anti-fouling effect It is aimed at letting.

In addition, an object of the present invention is to enable an enamel coating on a metal surface on which a polishing process is not performed.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

The composition of the enamel glaze composition for corrosion prevention and anti-fouling effect of the present invention power plant GGH and GAH ELEMENT to achieve the above object, the nickel acetate composite compound for preventing the formation of pores on the coating surface is 8 ~ 18% by weight, 80 to 90% by weight of clay in powder form, and 1 to 3% by weight of an additive mixed with silicate (silicate) and zirconium oxide (zirconia) for improving heat resistance and corrosion resistance.

In addition, the nickel acetate composite compound is preferably formed in the form of a powder and mixed with the clay, and after impregnating the additive in the clay preferentially, it is preferable to mix the nickel acetate composite compound and the clay.

Furthermore, the weight ratio of the silicate and the zirconium oxide (zirconia) contained in the additive is preferably 2-3: 7-8.

In addition, the silicate is preferably any one material selected from the group consisting of aluminum silicate, iron silicate, calcium silicate, magnesium silicate and alkali metal silicate.

Another embodiment of the present invention enamel coating method using the enamel glaze composition for the corrosion protection and anti-fouling effect of the GGH and GAH element for power plants, i) to provide a thermal element (thermal element) provided in the facilities of the power plant Making; ii) performing a heat treatment on the nickel acetate composite compound in powder form; iii) impregnating said additive in said clay; iv) mixing the nickel acetate composite compound with the additive-impregnated clay to form an enamel glaze composition; v) dispersing said enamel glaze composition in a liquid solvent to form an enamel coating solution; vi) performing enamel coating on the surface of the thermal element using the enamel coating solution; And vii) drying and calcining the enamel coated thermal element.

In this case, the heating element is preferably a heating element of the air preheater APH or a heating element of the gas-gas heater GGH.

Also, in the vi), the enamel coating is preferably carried out by dipping or spray injection.

Furthermore, the enamel coating layer formed by using the enamel coating method using the enamel glaze composition for corrosion prevention and anti-fouling effect of the GGH and GAH elements for power plants of the present invention is a heating element or a gas-gas heater (APH) of the air preheater (APH). GGH) can be used as a thermal element.

The effect of the present invention according to the configuration as described above, when the enamel coating on the surface of the metal product using the enamel glaze composition of the present invention, it is easy to form an enamel coating layer.

And, the effect of the present invention, when performing the enamel coating using the enamel glaze composition of the present invention, it is possible to improve the characteristics such as heat resistance, corrosion resistance and anti-fouling function of the enamel coating layer.

As a result, corrosion and blockages inside the power plant heat exchanger can be significantly prevented, thereby extending the period required for the replacement of the plant, thereby ensuring the stability of the plant operation and reducing the cost of replacing the plant. There are advantages to it.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a cross-sectional view of a metal plate coated using an enamel glaze composition according to an embodiment of the present invention.
Figure 2 is a schematic diagram of a thermal element coated using the enamel glaze composition according to an embodiment of the present invention.
Figure 3 is an enlarged view of the thermal element coated using the enamel glaze composition according to an embodiment of the present invention.
4 is a SEM image comparing the surface of the metal plate on which the enamel coating is performed using the enamel coating composition according to an embodiment of the present invention and the surface of the metal plate on which the enamel coating of the prior art is performed.
5 is a SEM image comparing the surface of the metal plate on which the enamel coating is performed using the enamel coating composition according to an embodiment of the present invention and the surface of the metal plate on which the enamel coating of the prior art is performed.
6 is a SEM image comparing the surface of the metal plate on which the enamel coating is performed using the enamel glaze composition according to an embodiment of the present invention and the surface of the metal plate on which the enamel coating of the prior art is performed.
Figure 7 is a SEM image comparing the cross section of the enamel coating layer using the enamel glaze composition according to an embodiment of the present invention and the cross section of the enamel coating layer of the prior art.
FIG. 8 is an SEM image comparing a cross section of an enamel coating layer using a enamel glaze composition according to an embodiment of the present invention with a cross section of an enamel coating layer of the related art.
Figure 9 is a SEM image comparing the cross-section of the enamel coating layer of the prior art enamel coating layer using the enamel glaze composition according to an embodiment of the present invention.
FIG. 10 is an image of each surface after an impact test is performed on the metal plate surface on which the enamel coating is performed using the enamel glaze composition according to an embodiment of the present invention and the surface of the metal plate on which the enamel coating of the prior art is performed.
FIG. 11 is an image of each surface of the metal plate surface on which the enamel coating is performed using the enamel glaze composition according to an embodiment of the present invention and the surface of the metal plate on which the enamel coating of the prior art is performed.
12 is an image for performing a decontamination experiment of the surface of the metal plate on which the enamel coating of the prior art was performed.
FIG. 13 is an image for performing a decontamination experiment on the surface of a metal plate on which the EHE enamel coating of the prior art is performed.
14 is an image for conducting a decontamination experiment on the surface of the metal plate on which the enamel coating is performed using the enamel glaze composition according to an embodiment of the present invention.
15 is an image for performing a decontamination experiment of the surface of the metal plate is subjected to the enamel coating of the prior art.
FIG. 16 is an image for performing a decontamination experiment on the surface of a metal plate on which the EHE enamel coating of the prior art is performed.
FIG. 17 is an image illustrating a decontamination experiment of a surface of a metal plate on which an enamel coating is performed using an enamel glaze composition according to an embodiment of the present invention.
18 is an image of a hydrophilic experiment of a metal plate surface on which an enamel coating of the prior art is performed.
19 is an image of a hydrophilic experiment of a metal plate surface on which the EHE enamel coating of the prior art was performed.
20 is an image of a hydrophilic experiment of the surface of the metal plate subjected to the enamel coating using the enamel glaze composition according to an embodiment of the present invention.
21 is a corrosive test of the metal plate surface on which the enamel coating of the prior art is performed, the surface of the metal plate on which the EHE enamel coating of the prior art is performed, and the surface of the metal plate on which the enamel coating is performed using the enamel glaze composition according to an embodiment of the present invention. The image for.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled) with another part, it is not only" directly connected "but also" indirectly connected "with another member in between. "Includes the case. In addition, when a part is said to "include" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a metal plate 200 coated using an enamel glaze composition for corrosion protection and anti-fouling effect of the power plant GGH and GAH element according to an embodiment of the present invention, Figure 2 is a view of the present invention A schematic diagram of a thermal element 300 coated using the enamel glaze composition according to an embodiment, Figure 3 is an enlarged view of the thermal element 300 coated using the enamel glaze composition according to an embodiment of the present invention It is also.

The enamel glaze composition of the present invention is used to form an enamel coating layer 100 for the surface of the metal plate 200 or the like, as shown in Figure 1, in particular, the enamel for the surface of the metal body is not easy to enamel coating It may be suitable for coating.

Specifically, enamel coating using the enamel glaze composition of the present invention may be performed on the thermal element 300 as shown in FIGS. 2 and 3. Here, the heating element 300 may be provided in an APH (Air Preheater) or GGH (Gas Gas Heater).

APH is a facility that improves thermal efficiency by heating the air supplied during the burning of coal by using the combustion gas directly from the boiler. Can be. The GGH is an apparatus for raising the temperature of the exhaust gas for the purpose of increasing the temperature of the smoke exiting the chimney and spreading it far to the atmosphere. The GGH may have a temperature range of 60 ° C. to 200 ° C. or less. In particular, GGH may be damaged by corrosion due to sulfuric acid due to low temperature corrosion in the range slightly above 80 ° C.

In the case of APH, the temperature is relatively higher than that of GGH, and the damage caused by thermal shock and abrasion by coal dust at a high speed may occur more frequently than the damage caused by sulfuric acid corrosion. In the case of GGH, damage due to low temperature corrosion of sulfuric acid corrosion may mainly occur.

When the thermal element of the APH is formed of a metal and the enamel coating of the thermal element of the APH is performed using the enamel glaze composition of the present invention, sand blasting or the like on the surface of the thermal element of the APH Enamel coating can be facilitated without performing the process. In addition, the thermal element of the APH has increased corrosion resistance, is prevented from being damaged by thermal shock or external impact, and the adsorption of enamel surface by ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) and dust and the resulting corrosion and product fluidity Problems such as problems caused by defects of the anti-fouling (Anti-Fouling) effect can be improved by the effect.

When the enamel coating on the thermal element of the APH is performed using the enamel glaze composition of the present invention, the above effect is realized when the enamel coating on the thermal element of the GGH is performed using the enamel glaze composition of the present invention. The same may also be implemented.

According to this, sufficient enamel coating performance such as heat resistance, acid resistance, hydrophilicity, etc. of the heat exchanger of the heat exchanger used in the prior art can be secured, which can significantly prevent corrosion and blockage inside the power plant heat exchanger. Since the required period can be extended, it is possible to secure the stability of the operation of the power plant, as well as to significantly reduce the cost of replacing the facility.

Hereinafter, the enamel glaze composition of the present invention will be described in detail.

The enamel glaze composition of the present invention used for the enamel coating on the metal surface may include 8 to 18% by weight of the nickel acetate composite compound, 80 to 90% by weight of clay, and 1 to 3% by weight of the additive. The enamel glaze composition of the present invention may be formed by mixing an additive-impregnated clay and a nickel acetate composite compound.

The nickel acetate composite compound may be formed in the shape of a powder. On the surface of the metal, components such as copper (Cu), chromium (Cr), and manganese (Mn), which are unsuitable for enamel coating, may be present. In particular, molten aluminum and carbon may be present, and carbon may be scale. Or may be a causal factor of chipping. When such materials act in combination, when enamel coating is performed on the surface of a metal by using an existing enamel glaze composition, large pores may be made by pushing out the gelled enamel layer due to surface tension during firing. In order to prevent such a phenomenon, it is to include a powdered nickel acetate composite compound in the enamel glaze composition of the present invention. In addition, the nickel acetate composite compound may be used as a heat resistance and corrosion resistance enhancing component.

In addition, the powder of the nickel acetate composite compound may be heat-treated at a temperature of 300 to 600 degrees (° C.). When the powder of the nickel acetate composite compound is heat-treated at a temperature below 300 ° C. or at a temperature above 600 ° C., the heat and corrosion resistance of the enamel coating layer 100 using the enamel glaze composition of the present invention may be reduced. Can be.

The clay may be in the form of a powder or in the form of lumps of larger diameter than the powder particles.

Additives may include silicate and zirconium oxide (zirconia). And the weight ratio ratio of the silicate and zirconium oxide contained in an additive may be 2-3: 7-8. Here, zirconium oxide may be changed to any one material selected from the group consisting of aluminum oxide (alumina, alumina), titanium oxide (TiO ₂ ), and calcium oxide (CaO). In such a case, the above ratio can be maintained.

Any material selected from the group consisting of aluminum silicate, iron silicate, calcium silicate, magnesium silicate and alkali metal silicate may be used as the silicate. In the enamel glaze composition of the present invention, the silicate may be used as a heat-resistant reinforcing component, and may be included in clay in the above ratio.

Aluminum oxide (Al ₂ O ₃ ) is a component for improving heat resistance and corrosion resistance, it may be included in the clay in the above ratio. In addition, zirconium oxide (ZrO ₂ ) is a component for improving corrosion resistance, and may be included in clay at the above ratio.

Hereinafter, the coating method of the present invention will be described.

In the first step, a thermal element 300 may be provided in the facility of the power plant. Details of the thermal element 300 may be the same as described above. Hereinafter, the thermal element 300 may collectively refer to the thermal element of APH and the thermal element of GGH.

In a second step, a heat treatment may be performed on the powdered nickel acetate composite compound. Then, in the third step, the additives can be impregnated into the clay. Next, in the fourth step, the nickel acetate composite compound and the additive-impregnated clay may be mixed to form an enamel glaze composition. In the fifth step, the enamel glaze composition may be dispersed in water to form an enamel coating solution. Here, it is described that the enamel glaze composition of the present invention is dispersed in water to form an enamel coating solution, but is not necessarily limited thereto. The enamel glaze composition of the present invention may be dispersed in another liquid to form an enamel coating solution. .

In a sixth step, the enamel coating may be performed on the surface of the thermal element 300 using the enamel coating solution. Here, the enamel coating may be performed by dipping or spray spraying. In the embodiment of the present invention has been described that the enamel coating is carried out in the above manner, but is not limited thereto.

In the seventh step, the enamel coated thermal element 300 may be dried and then fired. Here, the drying of the enamel-coated thermal element 300 is a temperature at which the water on the surface dries sufficiently, depending on the shape and size of the product, but can be viewed from 100 degrees to 400 degrees.

In addition, in order to harden the coated enamel glaze, it may be subjected to a process of baking for 10 to 20 minutes at a temperature of 830 ± 30 degrees (° C).

The heating element of the air preheater (APH) or the gas-gas heater (GGH) having the enamel coating layer using the enamel coating method of the present invention can be manufactured.

Therefore, when enamel coating is performed using the enamel glaze composition for corrosion prevention and anti-fouling effect of the power plant GGH and GAH element according to the present invention, such as heat resistance, corrosion resistance and anti-fouling function addition of the enamel coating layer. The characteristics can be improved, and the corrosion and blockages inside the power plant heat exchanger can be significantly prevented, so that the period required for the replacement of equipment can be extended, thereby ensuring the stability of the operation of the power plant and the replacement of the equipment. There is an advantage that can reduce the cost of the back.

Hereinafter, embodiments and experimental examples of the enamel coating using the enamel glaze composition of the present invention will be described.

[Example]

An enamel glaze composition comprising a nickel acetate composite compound powder heat-treated at a temperature of 300 to 600 ° C. was formed. Here, the enamel glaze composition includes 8 to 18 wt% of nickel acetate composite compound, 80 to 90 wt% of clay, and 1 to 3 wt% of an additive. The additives are aluminum silicate and zirconium oxide in the silicate, and are impregnated into clay at a weight ratio of 2-3: 7-8. Then, the nickel acetate composite compound powder and clay were mixed and then ground.

Next, after the enamel glaze composition formed as described above was dispersed in water to prepare an enamel coating solution, the enamel coating solution was applied to a metal plate formed of iron having a width of 20 cm, a length of 20 cm, and a thickness of 1 cm. The enamel coated metal plate 200 was dried for 5 to 10 minutes at a temperature of 200 ± 50 degrees (° C.) and calcined to perform enamel coating, thereby obtaining an enamel coated metal plate.

[Comparative Example 1]

After applying the commercially available enamel coating composition on a metal plate formed of iron having a width of 20 cm, a height of 20 cm, and a thickness of 1 cm, the metal plate coated with the enamel glaze composition was dried at a temperature of 200 ± 50 degrees (℃) for 5 to 10 minutes. After the firing to perform the enamel coating, an enamel coated metal plate was obtained.

[Comparative Example 2]

The commercially available acid-resistant enamel coating liquid (EHE) is applied to a metal plate formed of iron having a width of 20 cm, a length of 20 cm, and a thickness of 1 cm, and then the metal plate coated with the enamel glaze composition is applied at a temperature of 200 ± 50 degrees (° C). After drying for 10 minutes and calcined to perform enamel coating, an enamel coated metal plate was obtained.

4 (a) is a 50 times magnification SEM image of the metal plate surface obtained by [Comparative Example 1], and FIG. 4 (b) is a 50 times magnification SEM image of the metal plate surface obtained by [Example]. . In addition, Figure 5 (a) is a 150 magnification SEM image of the metal plate surface obtained by [Comparative Example 1], Figure 5 (b) is a 150 magnification SEM of the surface of the metal plate obtained by [Example] Image. 6 (a) is a 1,000 times magnification SEM image of the metal plate surface obtained by [Comparative Example 1], and FIG. 5 (b) is 1,000 times magnification SEM of the metal plate surface obtained by [Example]. Image.

As shown in (a) and (b) of FIG. 4, (a) and (b) of FIG. 5, and (a) and (b) of FIG. 6, it is formed of iron using the enamel glaze composition of the present invention. When the enamel coating is performed on the metal plate, foreign matter on the enamel coating surface using the enamel glaze composition of the present invention compared to the enamel coating surface of the prior art, protrusions and pin holes indicated by circles in FIG. It can be seen that this is significantly reduced. Accordingly, foreign matter adsorption efficiency to the enamel coating surface using the enamel glaze composition of the present invention can be significantly reduced. That is, acid resistance and pin-hole reduction effects and easy cleaning or anti fouling functions may be implemented.

Figure 7 (a) is a 50 times magnification SEM image of the cross section of the enamel coating layer obtained by [Comparative Example 1], Figure 7 (b) is 50 to the cross section of the enamel coating layer obtained by [Example] Magnification SEM image. In addition, Figure 8 (a) is a 150 times SEM image of the cross section of the enamel coating layer obtained by [Comparative Example 1], Figure 8 (b) is a cross section of the enamel coating layer obtained by [Example] SEM image of 150x magnification. And, Figure 9 (a) is a 1000 times magnification SEM image of the cross section of the enamel coating layer obtained by [Comparative Example 1], Figure 9 (b) is a cross section of the enamel coating layer obtained by [Example] SEM image of 1,000 magnification.

As shown in (a) and (b) of FIG. 7, (a) and (b) of FIG. 8, and (a) and (b) of FIG. 9, it is formed of iron using the enamel glaze composition of the present invention. When the enamel coating is performed on the metal plate, relatively more pores are formed in the enamel coating layer cross section using the enamel glaze composition of the present invention as compared with the cross section of the enamel coating layer of the prior art, and thus, It can be seen that the bonding force between the enamel coating layer using the enamel glaze composition and the surface of the metal plate formed of iron is increased, and the resistance to thermal shock of the enamel coating layer using the enamel glaze composition of the present invention is significantly increased. In addition, due to such a phenomenon, as described above, the pinhole of the enamel coating surface using the enamel glaze composition of the present invention may be significantly reduced.

Here, in the enamel coating layer using the enamel glaze composition of the present invention, the nickel acetate composite compound performs the function of binding other components, the additives can perform the function of dispersing bubbles during firing to reduce the maximum diameter of the pores have. This can be confirmed in (b) of Figure 9, as shown in Figure 9 (b), in the enamel coating layer using the enamel glaze composition of the present invention also has a number of shapes of the fiber structure such as (Thread) , The fiber structure is maintained even after the thermal shock, it can be seen that the resistance to thermal shock is significantly increased.

Experimental Example 1

An iron sphere having a weight of 2.56 kg and a diameter of 28 mm was dropped at a height of 430 mm toward the surface of the metal plate obtained in Example, and the surface of the metal plate obtained in Example was shocked. And the same impact as above was applied also to the metal plate surface obtained by [Comparative Example 1].

10A is an enlarged image of the surface of the metal plate obtained by [Comparative Example 1], and FIG. 10B is an enlarged image of the surface of the metal plate obtained by [Example]. As shown in FIG. 10, it was confirmed that after the impact as described above, white metal exposure was significantly higher on the metal plate surface obtained by [Comparative Example 1] compared to the metal plate surface obtained by [Example]. Accordingly, it can be seen that the durability of the enamel coating layer using the enamel glaze composition of the present invention is significantly increased.

Experimental Example 2

The metal plate obtained in Example was left in a constant temperature furnace at 400 ° C. for 20 minutes, and then immersed in water at room temperature for 5 minutes, and then dried for 5 minutes as one cycle, thereby providing a thermal shock of repeating 10 cycles. Surface defects were observed. And the same thermal shock was performed also about the metal plate surface obtained by [Comparative Example 1].

FIG. 11A is an enlarged image of the metal plate surface obtained by Comparative Example 1, and FIG. 11B is an enlarged image of the metal plate surface obtained by Example. As shown in Figure 11, during the thermal shock test as described above, the chipping (Chipping) occurred while the bubble (bubble) is broken in the thermal shock of 3 to 4 cycles on the surface of the metal plate obtained by [Comparative Example 1], [Example In the surface of the metal plate obtained by the] does not generate the chipping (Chipping) even in the thermal shock of 10 cycles, it can be seen that the enamel coating layer using the enamel glaze composition of the present invention is significantly increased resistance to thermal shock.

Experimental Example 3

Contaminants were applied to the surface of the metal plate obtained by [Example], and the metal plate obtained by [Example] was left at room temperature for 4 hours to form contaminants on the surface of the metal plate obtained by [Example]. The same contaminant formation was also performed on the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2]. Here, the pollutant was prepared in an amount of 20 g by mixing ammonium sulfate and sludge (gypsum) in a ratio of 9: 1.

Next, washing was performed on the metal plate obtained by [Example] where the pollutant was formed, the metal plate obtained by [Comparative Example 1], and the metal plate obtained by [Comparative Example 2]. Here, washing was performed by contacting each metal plate with running water for 10 minutes.

FIG. 12A illustrates an image of a contaminant formed on the metal plate obtained by Comparative Example 1. FIG. 12B illustrates a contaminant formed on the metal plate obtained by Comparative Example 1. FIG. It is an image of the matter to be washed in running water, Figure 12 (c) is an image of the surface of the metal plate obtained by [Comparative Example 1] after the cleaning is completed.

In addition, Figure 13 (a) is an image of the contaminants formed on the metal plate obtained by [Comparative Example 2], Figure 13 (b) is a contamination formed on the metal plate obtained by [Comparative Example 2] It is an image of the matter to wash the material in running water, Figure 13 (c) is an image of the surface of the metal plate obtained by [Comparative Example 2] after the cleaning is completed.

And, Figure 14 (a) is an image of the contaminants formed on the metal plate obtained by the [Example], Figure 14 (b) is a contaminant formed on the metal plate obtained by the [Example] It is an image of the matter to be washed in running water, Figure 14 (c) is an image of the surface of the metal plate obtained by the [Example] after the cleaning is completed.

As shown in FIG. 12C, the lower side of the contaminant formed on the surface of the metal plate obtained by [Comparative Example 1] was not completely removed, and corrosion was confirmed on the surface from which the contaminant was removed.

As shown in (b) and (c) of FIG. 13, the contaminants formed on the surface of the metal plate obtained by [Comparative Example 2] were washed at a slower rate than other metal plates, and the contaminants were completely removed. It was not removed. However, no corrosion was found on the metal plate surface obtained by [Comparative Example 2].

As shown in (b) and (c) of FIG. 14, all of the contaminants on the metal plate obtained by Example were absorbed between 1-2 minutes while absorbing water flowing through the metal plate obtained by [Example]. It was washed and no corrosion was found.

12 to 14, the contaminants formed on the surface of the metal plate obtained by [Example] were significantly better than the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2]. It can be confirmed that it is washed.

Experimental Example 4

Contaminants were applied to the surface of the metal plate obtained by [Example], and the metal plate obtained by [Example] was left at room temperature for 4 hours to form contaminants on the surface of the metal plate obtained by [Example]. The same contaminant formation was also performed on the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2]. Here, the pollutant was prepared in an amount of 20 g as 100% of the sludge (gypsum) material.

Next, washing was performed on the metal plate obtained by [Example] where the pollutant was formed, the metal plate obtained by [Comparative Example 1], and the metal plate obtained by [Comparative Example 2]. Here, washing was performed by contacting each metal plate with running water for 10 minutes.

(A) of FIG. 15 is an image of the contaminants formed on the metal plate obtained by [Comparative Example 1], and FIG. 15 (b) shows the contaminants formed on the metal plate obtained by [Comparative Example 1]. It is an image of the matter to be washed in running water, Figure 15 (c) is an image of the surface of the metal plate obtained by [Comparative Example 1] after the cleaning is completed.

In addition, Figure 16 (a) is an image of the contaminants formed on the metal plate obtained by [Comparative Example 2], Figure 16 (b) is the contamination formed on the metal plate obtained by [Comparative Example 2] It is an image of the matter to wash the material in running water, Figure 16 (c) is an image of the surface of the metal plate obtained by [Comparative Example 2] after the cleaning is completed.

And, Figure 17 (a) is an image of the contaminants formed on the metal plate obtained by the [Example], Figure 17 (b) is a contaminant formed on the metal plate obtained by the [Example] It is an image of the matter to be washed in running water, Figure 17 (c) is an image of the surface of the metal plate obtained by the [Example] after the cleaning is completed.

As shown in FIG. 15C, the contaminants formed on the surface of the metal plate obtained by [Comparative Example 1] were not completely removed, and surface corrosion was not confirmed.

As shown in (b) and (c) of FIG. 16, the contaminants formed on the surface of the metal plate obtained by [Comparative Example 2] were relatively slow to be washed than those of the other metal plates (8 to 9 minutes). ), The contaminants were completely removed and no surface corrosion was found.

As shown in (b) and (c) of FIG. 17, all of the contaminants on the metal plate obtained by [Example] were washed out within one minute, and no corrosion was found.

As shown in Figs. 15 to 17, contaminants formed on the surface of the metal plate obtained by [Example] are significantly better than the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2]. It can be confirmed that it is washed.

Experimental Example 5

Contaminants were applied to the surface of the metal plate obtained by [Example], and the metal plate obtained by [Example] was left at room temperature for 4 hours to form contaminants on the surface of the metal plate obtained by [Example]. The same contaminant formation was also performed on the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2]. Here, the pollutant was prepared in an amount of 20 g by mixing ammonium sulfate and sludge (gypsum) in a ratio of 9: 1.

Subsequently, immersion was performed on the metal plate obtained by [Example] where the pollutant was formed, the metal plate obtained by [Comparative Example 1], and the metal plate obtained by [Comparative Example 2]. Here, immersion was performed by immersing each metal plate in water for 5 minutes.

(A) of FIG. 18 is an image of a contaminant formed on the metal plate obtained by [Comparative Example 1], and FIG. 12 (b) shows that the metal plate obtained by [Comparative Example 1] is flooded for 5 minutes. This is an image of the metal plate surface obtained by [Comparative Example 1].

In addition, Figure 19 (a) is an image of the contaminants formed on the metal plate obtained by [Comparative Example 2], Figure 19 (b) is a metal plate obtained by [Comparative Example 2] 5 minutes This is an image of the metal plate surface obtained by [Comparative Example 2] after immersion.

And, Figure 20 (a) is an image of the contaminants formed on the metal plate obtained by the [Example], Figure 20 (b) is a metal plate obtained by the [Example] after immersion for 5 minutes It is an image of the metal plate surface obtained by the [Example].

As shown in (b) of FIG. 18, only a small amount of contaminants formed on the surface of the metal plate obtained by Comparative Example 1 was dispersed (mostly about 80%).

As shown in FIG. 19B, about 50% of the contaminants formed on the surface of the metal plate obtained by Comparative Example 2 remained.

As shown in (b) of FIG. 20, only about 20% of the contaminants formed on the surface of the metal plate obtained by [Example] remained.

As shown in Figs. 18 to 20, contaminants formed on the surface of the metal plate obtained by [Example] than the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2] are significantly less in water. Dispersed well, it was confirmed that the hydrophilicity of the metal plate obtained by Example.

Experimental Example 6

2.2 mg of 30% sulfuric acid was brought into contact with the surface of the metal plate obtained by Example, followed by heating at a temperature of 200 ° C. for 18 hours. In addition, the same sulfuric acid corrosion was performed on the metal plate surface obtained by [Comparative Example 1] and the metal plate surface obtained by [Comparative Example 2].

(A) of FIG. 21 is an enlarged image of the surface of the metal plate obtained by [Comparative Example 1], and FIG. 21 (b) is an enlarged image of the surface of the metal plate obtained by [Comparative Example 2], and FIG. 21. (C) is an enlarged image of the surface of the metal plate obtained by [Example].

After the corrosive test as described above, as shown in (a) of FIG. 21, the surface of the metal plate obtained by [Comparative Example 1] was found to have a serious coating peeling and thinning to reveal the material under the coating layer.

In addition, as shown in (b) of FIG. 21, compared with the metal plate surface obtained by [Comparative Example 1], the surface of the metal plate obtained by [Comparative Example 2] has no coating surface and the thinning state is also good. This was confirmed.

And, as shown in Fig. 21 (c), it was confirmed that the coating and thinning state of the metal plate surface obtained by [Example] is better than the metal plate surface obtained by [Comparative Example 2].

Accordingly, it was confirmed that the corrosion resistance of the surface of the metal plate obtained by [Example] is excellent.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified into other specific shapes without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined shape.

The scope of the invention is indicated by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the invention.

100: enamel coating layer
200: metal plate
300: thermal element

Claims (11)

In the enamel glaze composition used for enamel coating on the metal surface,
8-18% by weight of nickel acetate composite compound to prevent pore formation on the coating surface, 80-90% by weight of clay in powder form, and additives mixed with silicate and zirconium oxide for improving heat resistance and corrosion resistance Enamel glaze composition for corrosion protection and anti-fouling effect of the power plant GGH and GAH ELEMENT characterized in that it is prepared by mixing 1 to 3% by weight.
The method according to claim 1,
The nickel acetate composite compound is formed in the form of powder and enamel glaze composition for the corrosion protection and anti-fouling effect of the GGH and GAH ELEMENT for power plants, characterized in that mixed with the clay.
The method according to claim 1,
The enamel glaze composition for corrosion prevention and anti-fouling effect of the GGH and GAH ELEMENT for power plants, characterized in that the clay is impregnated with the additive preferentially, and then the nickel acetate composite compound and the clay.
The method according to claim 1,
The ratio of the weight ratio of the silicate (silicate) and the zirconium oxide (zirconia) included in the additive is 2 to 3: 7 to 8 for the corrosion protection and anti-fouling effect of the GGH and GAH element for power plants Enamel glaze composition.
The method according to claim 1,
The silicate is any one material selected from the group consisting of aluminum silicate, iron silicate, calcium silicate, magnesium silicate and alkali metal silicate to prevent the corrosion and anti-fouling effect of the GGH and GAH ELEMENT for power plants. Enamel glaze composition for.
delete In the enamel coating method using the enamel glaze composition of claim 1,
i) providing a thermal element provided in the installation of the power plant;
ii) performing a heat treatment on the nickel acetate composite compound in powder form;
iii) impregnating said additive in said clay;
iv) mixing the nickel acetate composite compound with the additive-impregnated clay to form an enamel glaze composition;
v) dispersing said enamel glaze composition in a liquid solvent to form an enamel coating solution;
vi) performing enamel coating on the surface of the thermal element using the enamel coating solution; And
vii) enamel-coating the heating element after the enamel-coated thermal element; enamel coating method using the enamel glaze composition for the corrosion protection and anti-fouling effect of the GGH and GAH ELEMENT for power plants comprising a.
The method according to claim 7,
The heating element is a heating element of the air preheater (APH) or a gas-gas heater (GGH) of the heating element, characterized in that using the enamel glaze composition for the corrosion protection and anti-fouling effect of the GGH and GAH element for power plants Enamel coating method.
The method according to claim 7,
In the vi) step, the enamel coating is enamel coating method using the enamel glaze composition for the corrosion protection and anti-fouling effect of the GGH and GAH ELEMENT for power plants, characterized in that performed by dipping (dipping) or spray injection.
A heating element of an air preheater (APH) comprising an enamel coating layer formed by using an enamel coating method using an enamel glaze composition for corrosion protection and anti-fouling effect of the power plant GGH and GAH element of claim 7.
Heat of the gas-gas heater (GGH) comprising an enamel coating layer formed by using an enamel coating method using an enamel glaze composition for corrosion protection and anti-fouling effect of the power plant GGH and GAH element of claim 7 device.

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