KR100669843B1 - Absorbent composition of radiant heat energy and product manufactured by coating the same on a surface of the product - Google Patents

Abstract

The present invention provides a radiant heat energy absorbent composition, and heat-exchanging parts (heat exchange devices) such as metal sheets, pipes, and fins, in which heat exchange is performed by heat radiation, and inner wall surfaces of high-temperature heating furnaces and the like. It is intended to improve radiant heat energy absorption and thermal conductivity by improving the thermal efficiency and thermal durability.

Radiant Heat Absorber Composition, Metal Oxide, Methyltrimethoxysilicate, Aluminum Phosphate

Description

A radiant heat energy absorbent composition and a radiant heat energy absorbent product manufactured by coating the same on a surface of the product {Absorbent composition of radiant heat energy and product manufactured by coating the same on a surface of the product}

1 is a comparative experiment result of the temperature change of water by external heating by coating the absorbent composition copper pipe of the present invention and filled with water inside.

Figure 2 is a comparative experiment result of the water temperature rise change inside the container when the heating by coating the radiant heat energy absorbent composition of the present invention on the bottom of the aluminum fry pan.

3 is a comparison test result of the surface temperature rise change of the plate when heated by coating the radiant heat energy absorbent composition of the present invention on an aluminum plate.

FIG. 4 is a comparative test result when the same test as in FIG. 3 was performed by sandblasting an aluminum plate. FIG.

5 is a comparative experiment result of the temperature rise change according to the height when heated from the bottom by coating the radiant heat energy absorbent composition of the present invention in a stainless steel pipe.

In general, a thermally radioactive paint is used to increase the amount of radiation heat transfer in a heating furnace of a high temperature operation. These materials are pulverized silicon carbide with fine powder to add a binder or other additives. Slurry with water or alcohol and apply to the inner wall of the furnace with a spray gun. On the other hand, in an oxidizing atmosphere of 800 ° C. or higher, silicon carbide is oxidized and turned into a white oxide, which lowers the emissivity. Therefore, in a furnace of 1200 to 1300 ° C., a durable chromite is pulverized by pulverizing durable chromite. A heat-radiating composition containing heat-resistant frit is prepared and applied to the inner wall of the furnace with a spray gun or the like (Japanese Patent Laid-Open No. 1998-274482, SO 57-109868).

Thus, the radiation capacity (heat absorption capacity) of the inner wall of the furnace is increased by the application of the thermally radioactive paint, which shortens the temperature rise time of the furnace, increases the radiant heat of the heated object, and reduces the amount of heat emitted outside the furnace. Can reduce fuel consumption. The fuel saving rate is reported to have an effect of about 2 to 20% depending on the shape of the furnace and the operating conditions. However, these thermally radioactive coating compositions are generally applied to the surface of the ceramic layer of the furnace wall. In order to be applied to a metal plate or the like, desorption phenomenon occurs due to a difference in thermal expansion coefficient between the metal plate and the thermally radioactive paint at high temperature. It is easy to occur and has a problem in its adhesiveness, so it is not applicable to a plate of general metal products, copper products such as pipe or boiler burners or aluminum metal embedded heaters and aluminum cookers used for high heat.

Therefore, in the present invention, the radiant heat energy absorbent composition is developed, and the radiant heat energy absorbent composition has good adhesion at a high temperature (about 800 ° C.) to any kind of substrate such as iron, stainless steel, nonmetal plate (copper, aluminum) and ceramic material. Metal coated with the radiant heat absorbent composition of the present invention having excellent heat conduction and radiant heat energy absorption and reducing the desorption of the radiant heat energy absorbent of the present invention applied to the metal and the metal due to the difference in coefficient of thermal expansion at high temperature. In addition to improving the thermal efficiency of heat exchange products made of plates or pipes, etc., it was intended to find ways to extend the durability of the products.

In the present invention, a radiant heat energy absorbent composition is formed by mixing a mixture of metal alkoxides or a colloidal substance or metal phosphate of these metal oxides with a binder of various metal oxides and a metal material as a base material. When the radiant heat energy absorbent composition is coated on a metal material and the polymerization reaction occurs, it is firmly attached to the surface of the metal plate. When the heat is applied after the polymerization, the radiant heat energy absorbing layer is gradually evaporated to organics, which is converted into ceramics. It exhibits a dense coating performance in which no desorption phenomenon occurs with and the radiant heat energy absorbing layer.

Further, in order to increase the coating performance, the surface of the metal material may be roughened by sand blasting or the like to improve adhesion. In addition, since the radiant heat energy absorbent composition of the present invention is composed of a stable metal oxide, it exhibits corrosion resistance to compounds such as acids and alkalis, and thus, when coated on a heating part of a heat exchanger composed of copper plates, fins, and pipes, such as a domestic boiler, Corrosive sulfur compounds and the like contained in oil, etc., exhibit anticorrosive properties, and not only improve the thermal efficiency according to the radiant heat energy absorption performance, but also prevent corrosion of metal materials, thereby extending the life of the boiler and the like. In addition, coating on the bottom heating surface of an aluminum pot or frying pan can reduce the boiling time of water through rapid radiant heat transfer, thereby improving thermal efficiency.

The materials of the radiant heat energy absorbent composition of the present invention are single or complex compounds such as metal oxides, carbides, nitrides, fluorides, or silicon compounds. Typical examples include Cr ₂ O ₃ , Al ₂ O ₃ , Fe ₃ O ₄ , SiO ₂ , TiO ₂ , ZrO ₂ , CuO, MnO ₂ , NiO, ZrSiO ₄ , SiC, TiN, TiC, C, and the like.

By using a metal alkoxide or colloidal compound as a binder, it is possible to mix a large amount of radiant heat energy absorber material compared to a silicate coating or a thermal spraying method, which is generally used for coating metal plates or ceramic surfaces of powder products. Can be improved.

The metal alkoxide used in the present invention is represented by the general formula R ₁ M (OR ₂ ) n wherein R ₁ is an alkyl group having 0 to 3 carbon atoms, R ₂ is a hydroxyl group, methoxy, ethoxy substituent and M is silica or other metal to be. Typical examples include (CH ₃ ) ₃ SiOC ₂ H ₅ , Si (OC ₂ H ₅ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Al (OC ₂ H ₅ ) ₄ , and Zr (OC ₂ H ₅ ) ₄ . have. Aluminum phosphate (Al ₂ (H ₃ PO ₄ ) nH ₂ O was used as the metal phosphate.

In the present invention, as described above, in order to improve the heat radiation efficiency of a boiler or a heating furnace, it is applied to the surface of the heating unit, 18 wt% SiO2, 34 wt% Al ₂ O ₃ , Cu (Cr, Fe) ₂ Black pigment containing 28 wt% O ₄ and up to 3 wt% (Al ₂ O ₃ + SiO ₂ ) impurities and Fe ₂ O ₃ in the range of 92 to 96 wt% Bayerrox Schwarz / Black 306, 316, 318, 318M or equivalent pigment 6 wt% , TiO ₂ 5 wt%, (Co, Ni, Zn) ₂ (TiAl) O ₄ 9 wt% To 35% by weight, 40 to 45% by weight of colloidal metal oxide, 20 to 30% of metal alkoxide, 5 to 10% of metal phosphate, 1 to 10% of water, 65 to 75% of synthetic inorganic binder composed of 20 to 30% of alcohol It is made of the prepared slurry and applied to the base material (copper, stainless steel, aluminum plate) by using a spray gun, etc., and then dried naturally and heated at about 300 ℃ for 40 minutes to organic matter. To thereby a precise and stable fixation of radiation energy-absorbing layer on the surface of the base material evaporates.

Hereinafter, specific examples of the radiant heat energy absorbent composition of the present invention will be described.

<Example 1>

In the above radiant heat energy absorbent composition, SiO ₂ 18%, Al ₂ O ₃ 34%, Cu (Cr, Fe) ₂ O ₄ 28%, Fe ₂ O ₃ (Al ₂ O ₃ + SiO ₂ ) having a particle size of about 10 μm or less. 6%, TiO ₂ 5%, (Co, Ni, Zn) ₂ (TiAl) O ₄ 9% by weight of the composition mixed with 42% by weight of colloidal silica and 5% by weight of aluminum phosphate and trimethoxy A binder synthesized from silane, alcohol, and water was added to prepare a composition in a slurry state of about 71%. The radiant heat energy absorbent composition of the present invention thus prepared was coated on the outside of the copper pipe, dried at room temperature, and heated to about 200 ° C. to fix the coating film.

1 is coated with a radiant heat energy absorbent composition of the present invention on the outside of the copper pipe (diameter 22 mm × length 500 mm), and filled the water inside the copper pipe to change the temperature change of the water by external heating without coating the radiant heat energy absorber composition Experimental results compared with the case.

Referring to the experimental result of Figure 1, it can be seen that the temperature rise of the water inside the copper pipe coated with the radiant heat energy absorbent composition of the present invention shows a significantly faster synergistic effect than the case of the copper pipe without coating. As can be seen in FIG. 1, after 2 minutes of heating, the temperature of 20 ° C., which is almost the same as that of the present invention, is coated or uncoated. However, after 10 minutes of heating, the temperature of the water of the copper pipe coated with the radiant heat energy absorbent composition of the present invention increases to about 80 ° C., but the temperature of the water in the uncoated pipe only rises to about 50 ° C. Can be.

<Example 2>

The radiant heat energy absorbent composition having the same composition as in Example 1 is applied to the heat exchanger fin and the pipe of the gas water heater (product name: Rinnai RUS-55FT) with a spray gun at a thickness of about 30 to 50 μm. After coating, the film is dried naturally and heated for 1 hour in a muffle furnace of about 200 ° C. in an oxidizing atmosphere to volatilize an organic material and the like to fix the radiant heat energy absorbing layer formed on the surface of the heat exchanger.

In order to determine whether the thermal efficiency is improved, the gas boiler coated with the radiant heat energy absorbent composition and the gas boiler not coated with the absorbent composition are operated under the same operating conditions to observe the temperature of hot water and exhaust gas discharged. Compared to each other, the efficacy of the radiant heat energy absorber of the present invention was compared and examined.

Table 1 shows the operation results of the above two boilers. When the same operation condition is maintained, that is, when the water supply is kept constant and a certain amount of gas is combusted, the temperature of the discharged hot water is not applied in the case of the gas boiler coated with the radiant heat energy absorbent composition. It can be seen that it is about 3 ℃ higher than the boiler and the exhaust gas temperature is 153 ℃ 72 ℃ lower than the exhaust gas temperature (225 ℃) of the uncoated gas boiler.

Effluent temperature (℃) Exhaust temperature (℃) Remarks Absorbent composition coating 64 153 Temperature when equilibrium is reached Uncoated 61 225

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※ Operational condition: Supply same amount of water and gas

<Example 3>

A slurry made of the radiant heat energy absorbent composition of Example 1 was made and coated on the bottom of an aluminum fry pan (2000 ml) to a thickness of about 10 to 30 μm, and then dried naturally and heated at about 200 ° C. for 1 hour to remove volatile components. Form a dense coating film. As described above, the same amount of water is added to the frying pan (A) and the unapplied frying pan (B) to which the radiant heat energy absorbent composition of the present invention is applied, and the water is evaporated under the same heating conditions. The temperature rise of water and its evaporation rate were compared. The experimental result is shown in FIG. As can be seen in Figure 2 the temperature of the water of the frying pan (A) coated with the radiant heat energy absorbent composition of the present invention is higher than the case of the frying pan (B) uncoated until the temperature of boiling water approaches the same In heating conditions, the time required to evaporate 1000 ml of water to steam is 90 minutes in case of A, whereas 242 ml of water remains after 90 minutes in case of B, and the fry pan coated with the radiant heat energy absorbent composition of the present invention. It can be seen that the performance is excellent.

<Example 4>

A radiant heat energy absorbent composition as in Example 3 was prepared to make a slurry, coated on an aluminum plate with a thickness of about 10 to 30 μm, dried naturally, and heated at about 200 ° C. for about 1 hour to remove volatiles to form a dense coating film. It was. Meanwhile, the surface of the aluminum sheet was sand blasted to be rough, and then coated with the same absorbent composition as described above. The plate size was the same and the absorber coated portion was heated at a certain distance from the heater to observe the change in surface temperature rise of the plate.

3 is an experimental result comparing the case where the aluminum plate is coated with the radiant heat energy absorbent composition without sand blasting and without coating. As can be seen in FIG. 3, the temperature of the plate coated with the radiant heat energy absorbent composition is increased to 90 ° C. after 5 hours from 90 ° C. after 1 hour, but in the case of a plate not coated with the radiant heat energy absorbent composition, After 1 hour has elapsed from 60 ℃ to about 140 ℃ after 5 hours, it can be seen that the heat transfer effect by the radiant heat energy absorbent composition of the present invention is excellent. FIG. 4 shows that the surface of the plate is not sandblasted and shows similar results as in FIG. 3.

<Example 5>

A slurry made of the radiant heat energy absorbent composition of Example 1 was made and coated in a stainless pipe (diameter 120 mm) to a thickness of about 10 to 30 μm, dried naturally, and heated at about 200 ° C. for about 1 hour to remove volatiles, and thus, to prepare a slurry. A coating film was formed.

5 is an experimental result of examining the temperature distribution according to the height of the pipe when the stainless pipe is erected vertically and installed by heating a heater on the bottom of the stainless pipe. In FIG. 5, A-40 and B-40 are temperature changes according to time measured at a height of 40 mm from the bottom of the pipe, and A-160 and B-160 are measured at a time of 1600 mm from the bottom of the pipe. Temperature change accordingly.
According to the experimental result of FIG. 5, the temperature rise of the 40 mm height at the bottom of the pipe is very high compared to the pipe B-40 without the pipe A-40 coated with the absorbent. In other words, the pipe (A-40) coated with a radiant heat energy absorber increases to about 330 ° C after about 5 minutes at about 140 ° C after 2 minutes, but after about 2 minutes after pipes (B-40) After 5 minutes at 97 ° C., the temperature was increased by about 250 ° C., indicating a difference of about 80 ° C. That is, it can be seen that the heat generated from the heater of the pipe coated with the radiant heat energy absorbent composition is absorbed by the bottom side of the pipe coated with the absorbent.
On the other hand, the temperature measured at 160mm from the bottom indicates that the pipe (A-160) coated with a radiant heat energy absorber shows about 60 ° C after 5 minutes and 125 ° C after 5 minutes has elapsed. In the case of B-160), it can be seen that the temperature rise is higher than the pipe coated with the absorbent at about 185 ° C. after 5 minutes at about 90 ° C. after 2 minutes. This phenomenon is because the heat absorbing effect of the radiant heat energy absorbent composition of the present invention is so large that when a constant heat energy is supplied, heat is absorbed from the bottom portion (about 40 mm from the bottom) to radiate heat into the outside air of the pipe. The amount of heat energy transmitted to the bottom (about 160 mm from the bottom) is reduced (because it has already absorbed heat from the inner coating surface of the bottom of the pipe and has already radiated to the outside air), thereby proving that the temperature rise is lowered.

The radiant heat energy absorbent composition of the present invention is excellent in thermal radiation efficiency, thereby saving fuel by improving the thermal efficiency of a boiler or a furnace operating at a high temperature (about 300 ° C. or more) coated thereon. In addition, the application of stable metal oxides to chemicals has the advantage of extending the life by improving the corrosion resistance of metal materials such as boiler combustion chamber and heat exchanger.

Claims (3)

18 wt% SiO2, 34 wt% Al ₂ O ₃ , Bayferrox Fast Black of Bayer Co., Ltd. (28 wt% of Cu (Cr, Fe) ₂ O ₄ ) or its equivalent pigment, (Al ₂ O ₃ + SiO ₂₎ ) impurities up to 3% by weight and 92-96% by weight of Fe ₂ O ₃ a (main) Bayer (Bayer)社Bayferrox Black or 6% by weight, its equivalent pigment containing, TiO ₂ 5% by weight, (Co, Ni-Zn) ₂ (TiAl) O ₄ Bayer Co., Ltd. Bayferrox Green or 25 to 35% by weight of the oxide mixture having a particle size of less than about 10㎛; And 40 to 45% by weight of colloidal silica, 20 to 30% by weight of metal alkoxide, 5 to 10% by weight of metal phosphate, 1 to 10% by weight of water, and 65 to 75% by weight of synthetic inorganic binder composed of 20 to 30% by weight of alcohol. A radiant heat energy absorbent composition, characterized in that consisting of. The radiant heat energy absorbent composition of claim 1 is applied to a heat exchanger heating part (pipe, fin or peripheral part) of any one of metal, copper, stainless steel, aluminum, and iron with a spray gun at a thickness of 10 to 30 μm, and dried naturally. A radiant heat energy absorbing product characterized by producing a heat exchanger coated with a dense radiant heat energy absorbent composition by heating in a muffle furnace at 200 to 300 ° C. delete

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