JP2774982B2 - Water pipe protection material and water pipe protection wall used for incinerators, etc. - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water pipe protection material and a water pipe protection wall to be installed on a water pipe used in an incinerator for incinerating municipal garbage, industrial waste, and the like. It is.

(Prior art) In an incinerator for incinerating municipal garbage, industrial waste, etc., a combustion chamber, which is a part for burning waste, an exhaust gas treatment chamber,
It is common to provide refractories and water-cooled walls in the flue.

With the water-cooled wall, the heat of combustion is recovered together with the incineration of waste.

The structure of the water-cooled wall described above is different from that of simply providing a water pipe on the side wall of the flue of the combustion chamber, by attaching fins to the water pipe and interposing a castable refractory material between the fins of the water pipe.
In addition to the technology described in Japanese Patent Publication No. 11295, there is also a construction example in which a water pipe itself constituting a water cooling wall is covered with a chromium or chamotte-shaped irregular refractory.

(Problems to be Solved by the Invention) Generally, the gas generated in an incinerator for incinerating municipal garbage, industrial waste, etc. differs depending on the combustion products, but includes sulfuric acid gas and chlorine gas, and removes these. And release it to the atmosphere.

However, when recovering combustion heat in an incinerator, it is necessary to consider the effects of the sulfuric acid gas and chlorine gas, and also to consider the effects of each alkali gas such as potassium salt.

That is, the water pipe for heat recovery may corrode under the influence of the above-mentioned sulfuric acid gas and chlorine gas, and high-pressure steam may be ejected from the water pipe into the furnace to cause an explosion.

The technique described in Japanese Patent Publication No. 60-11295 is aimed at preventing clinker from adhering to the combustion stoker portion, and heat in the furnace is effectively transmitted to the water pipe to some extent through the fins.

However, there is a possibility that furnace gas contained in the furnace may enter from between the fins and the castable refractory material.

Therefore, an example of construction has been considered in which the water pipe itself constituting the water cooling wall is covered with an irregular refractory.

That is, in order to absorb heat energy into the water pipe as smoothly as possible, the irregular shaped refractory must be (1) stable in the furnace gas, (2) not subject to heat or molten ash, ) Conditions such as a material that easily conducts heat to boiler water are required.

Therefore, at present there are examples of construction covered with irregular shaped refractories of chamotte quality, but the resistance to the harmful exhaust gas components is small, and there is no adhesion to water pipes,
Heat transfer to the boiler water is disadvantageous due to its low thermal conductivity compared to the case of chromium, and there is a problem in the original purpose of protection of the water pipe and efficient heat recovery.

In the present invention, a protective wall that is stable against gas in the furnace, does not suffer from obstacles such as heat or ash, and transmits heat more effectively to boiler water with a higher thermal conductivity than chromium,
Another object of the present invention is to provide a water pipe protection material that is easy to construct.

(Means for Solving the Problems) The present invention contains a liquid component comprising about 5 to 20% by weight of an aluminum phosphate solution and about 10 to 80% by weight of silicon carbide, and the remainder is chamotte, electrofused or Sintered mullite, electrofused or sintered alumina, kyanite, selven, spinel,
It has a dense structure such as zircon and has a low reactivity with the aluminum phosphate solution, but it consists of a refractory aggregate composed of appropriate materials and a powder component composed of fine powder. Is a water pipe protective material used for incinerators and the like characterized by kneading, and is used in incinerators and the like in which a coating layer is formed on the inner surface side of a water pipe on the inner wall of a combustion chamber flue of an incinerator with the water pipe protective material. It is a water pipe protection wall.

(Action) By containing about 10% by weight or more of silicon carbide as a main component of the present invention, heat conduction is good and efficient heat recovery can be performed. In addition to effectively acting on corrosive gas in addition to the properties described above, it can also have abrasion resistance.

Also, since the powder component containing silicon carbide as a main component and the liquid component of the phosphate solution are separated, the storage stability is good. Further, at the time of construction, the powder component and the liquid component are kneaded, and when coating the inner surface side of the water pipe having the inner wall of the flue of the combustion chamber of the incinerator, using a phosphate solution as a binder, chemically at room temperature and It cures rapidly, does not require water curing, and acts to improve workability.

(Example) Hereinafter, an example in which the present invention is applied to a general combustion furnace will be described.

The combustion furnace incinerates the incineration material charged from the charging hopper with the combustion stoker 5, and removes pollutants from the exhaust gas through the combustion chamber and discharges it to the outside. The water pipe 2 is provided on the inner surface of the combustion chamber side wall 3 above the combustion stoker 5, and the heat recovered from the water pipe 2 is sent to the boiler drum 7.

Here, the water pipe 2 is mounted on the combustion chamber side wall 3 along the inner surface of the combustion chamber side wall 3 as shown in FIG. Each of the two water tubes is connected by a plate-shaped body 6 and is formed in a tubular shape to form a water cooling wall. The water pipe 2 is provided with a large number of fins 4 inward.

Next, a description will be given of an example in which a plastic refractory made of a powder component mainly containing silicon carbide and a liquid component of a phosphate solution such as aluminum primary phosphate is used for the water pipe 2 in the combustion chamber.

The powder component is silicon carbide [SiC] 10 to 80% by weight,
Chamotte, fused alumina, sintered alumina, ultra-fine powder of silica or the like in one kind or in any combination, 5 to 30% by weight, refractory clay 10% by weight or less It has a dense structure such as electrofused or sintered alumina, cannite, cerbene spinel, and zircon, and is a refractory aggregate and a fine powder having low reactivity with a phosphate solution.

As for the liquid component, 5% aluminum phosphate solution was used.
Used in the range of 2020% by weight.

In addition to the powder component and the liquid component, for example, 0.5 to 3.0% of magnesium oxide, 0.5 to 5.0% of carboxylic acid, and 0.3 to 3.0% of inhibitor are added.

Here, magnesium oxide cures the material at normal temperature and reduces linear shrinkage. The carboxylic acid is used for the purpose of reducing the amount of the blended liquid and securing the working time. In addition, the inhibitor suppresses the reaction of the iron component in the powder component and prevents corrosion of the water tube 2 by the liquid component.

The above-mentioned powder component, liquid component and other additives are put into, for example, a mortar mixer and kneaded at room temperature, and a water pipe protective wall is formed by tapping (patching) so as to cover the side of the water pipe 2 through which the furnace gas passes.

Although the construction is performed as described above, a kind of peptization occurs in the ultrafine powder and the phosphate as the kneading progresses. For this reason, even though the component is a high-viscosity plastic refractory, kneading with a mortar mixer is possible, and the amount of the solution is reduced to be dense.

Tables 1 and 2 show examples of working in the above component ranges. Table 1 shows examples of the contents of the components. Table 2 shows physical property comparison values between Examples 1 to 4 of the present invention and comparative products. It is.

As a comparative product in the above-mentioned physical property test, a chromic plastic refractory was used.

Ingredient composition is chromite ore 4-1mm 50% by weight, less than 1mm
38% by weight, 2% by weight of plasticizer (refractory clay), 10% by weight of binder and added water.

In the acid resistance test, the size of the test piece is 40 × 40 × 160m
After curing at 20 ° C. for 24 hours, the sample was calcined at 400 ° C. for 3 hours. Then, after being immersed in a 1% hydrochloric acid solution for 48 hours, it was washed with water, dried at 110 ° C. for 18 hours, weighed, and expressed in percentage.

In the panel heating test, a stud was planted at a diameter of 9φ, a length of 35mm, and a pitch of 50mm on a flat panel of 500 × 500mm with a thickness of 35mm. (No trimming to flatten the surface while hitting was performed.) After the application, it was cured at 20 ° C. for 24 hours and set in a heating furnace. Heating condition is 650 ℃ at 100 ℃ / hr
Temperature, hold for 2 hours, digest, and cool naturally in a furnace. After cooling, observe the panel condition.

Comparing the component components 1 to 4 according to the present invention with the comparative examples, the product of the present invention has a linear change rate of 0.2 to 0.5% shrinkage, whereas the chromium-based comparative product has a shrinkage of 2%. As can be seen, the product of the present invention is a plastic refractory but has a linear change rate comparable to that of a castable refractory. Therefore, when this composition is applied to a water-cooled wall, it is difficult to form a gap between the coating layer 1 and the water pipe 2, and as is clear from the panel heating test, the comparative product has a "surface crack" even in a heated atmosphere. Although "cracks" occurred, the component components 1 to 4 of the present invention maintained a stable surface state,
Cracks do not occur and corrosive combustion exhaust gas such as chlorine gas and sulfuric acid gas can be prevented from entering.

Further, as is clear from the above-mentioned acid resistance test, the material forming the coating layer 1 has an acid resistance of about 10 to 15% of that of the comparative product, which is eroded by acid and causes a reduction in volume. It can be applied sufficiently even in a gas atmosphere, and the frequency of maintenance can be reduced by applying it to the water cooling wall of an incinerator.

In addition, compounding silicon carbide with appropriate particle size adjustment,
Further, permeation of the alkali salt can be further reduced because a kind of peptization occurs between the ultrafine powder and the phosphate.

Furthermore, in terms of heat conduction, it is about 1.2 to 3.8 compared to chromium-based comparative products that have better heat conduction than chamotte-based refractories.
The heat conduction is twice as good and efficient heat recovery can be achieved. In the above example, curing was performed at 20 ° C. for 24 hours.However, this was a chemical bond using a phosphate solution as a binder, so that curing was performed at room temperature without the need for water curing and heating was performed. There is no need for drying.

Further, since the binder becomes insoluble in the heating state at a relatively low temperature, it is also effective against water vapor generated from dust.

(Effect of the Invention) The present invention is configured and operates as described above, and has the following excellent effects.

Since the water tube protective material is divided into a powder component and a liquid component, it has good storage stability and is easy to handle.

When the water pipe protection material is applied to the water pipe and the water pipe protection wall is applied, the tapping work (patching) can be performed, and the gap between the coating layer and the water pipe is hardly formed because the coating layer and the water pipe are better bonded. Can be prevented.

Since the components of the water pipe protection material can be mixed with a mortar mixer while being a plastic refractory, the workability is extremely high even after the installation of the combustion furnace, as in the case of working in a combustion furnace assembly factory, It is also possible to apply to a conventional combustion furnace.

The water pipe protection material is stable against the gas inside the furnace, is not affected by heat or ash, and is a material that easily conducts heat to the boiler water. Since the component is made of silicon carbide having a high thermal conductivity, heat can be effectively recovered, and also has abrasion resistance.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a sectional view of a combustion chamber side wall, FIG. 2 is a partially enlarged sectional view of FIG.
The figure is a configuration diagram of a combustion furnace and a boiler. 1 is a coating layer, 2 is a water pipe, 3 is a combustion chamber side wall, 4 is a fin,
5 is a combustion stoker, 6 is a plate-like body, 7 is a boiler drum.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuhiro Toyama 1-6-14 Edobori, Nishi-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Ryosuke Nabeta 1-6-16-1 Edobori, Nishi-ku, Osaka-shi, Osaka No. Hitachi Shipbuilding Co., Ltd. (72) Inventor Eiroku Kamiyama 1-6-14 Edobori, Nishi-ku, Osaka-shi, Osaka Hitachi Shipbuilding Co., Ltd. (56) References Japanese Utility Model Sho-61-149604 (JP, U) 60-49155 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23G 5/44 F23M 5/08 F23M 5/00 C04B 35/66

Claims (2)

(57) [Claims] 1. An aluminum monophosphate solution of about 5 to 20
About 10 to 80% by weight of silicon carbide and about 10 to 80% by weight of silicon carbide, the remainder being chamotte, electrofused or sintered mullite, electrofused or sintered alumina, kayanite, selven, spinel, zircon, etc. An incinerator characterized in that it comprises a refractory aggregate made of an appropriate material but a powder component consisting of a fine powder, but has a low reactivity with an aluminum phosphate solution, and a liquid component and a powder component are kneaded during construction. Water tube protection material used for etc. 2. A water pipe protection wall used for an incinerator or the like, wherein a coating layer is formed on the inner surface side of a water pipe such as a boiler attached to the incinerator with the water pipe protection material according to claim 1.