JPH0849980A - Lining structure of furnace wall - Google Patents

Abstract

PURPOSE:To provide a lining structure of a furnace wall which has a high resistance to a reducing gas such as hydrogen gas and alkali with excellent resistance to the velocity of wind and sufficient endurance. CONSTITUTION:A ceramics fiber block 1 is fixed with a fixing member 3 anchored on an iron matte 2 and a protective layer 4 in which an alumina fiber cloth 5 and a mixture of an alumina powder and an inorganic binder are laminated to be formed into a one-piece plate is fixed with a fixing pin 6 to complete a lining structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a furnace wall lining structure.

[0002]

2. Description of the Related Art Conventionally, as a lining structure of a furnace wall of an industrial heating furnace, ceramic fiber or rock wool,
BACKGROUND ART A lining structure in which a heat-resistant inorganic fiber heat insulating material such as a felt or blanket of heat-resistant inorganic fiber such as alumina fiber or a block obtained by laminating and compressing these is fixed to an iron shell which is an outer shell of a furnace is widely used. The lining structure composed of such a heat-resistant inorganic fibrous heat insulating material layer has good heat insulating properties and has a small heat capacity, so that the thermal efficiency of the heating furnace is good, and the heat shock resistance is excellent. However, it has inferior wear resistance and wind speed resistance, and has drawbacks such as scattering of fibers or shots as a base material by high-speed gas. Further, ceramic fibers and rock wool are easily attacked by reducing gas such as hydrogen gas and alkali. Although alumina fiber has corrosion resistance to reducing gas such as hydrogen gas and alkali, alumina fiber is expensive, and if the lining of the furnace wall is made of only alumina fiber heat insulating material, it will be extremely expensive. .

Therefore, in order to solve the above-mentioned drawbacks of the lining structure composed of the heat-resistant inorganic fibrous heat insulating material layer, a lining structure in which various coatings are applied to the inner surface of the furnace of the ceramic fiber heat insulating material layer (for example, ,
Japanese Patent Publication No. 60-18295 and Japanese Patent Publication No. 63-56194), and a lining structure in which a ceramic sintered plate is attached to the inner surface of the ceramic fiber heat insulating material layer (for example, Japanese Utility Model Publication No. 53-65026 and Japanese Utility Model Publication No. 62-777
No. 97, etc.), a lining structure in which the inner surface of the ceramic fiber heat insulating material layer is covered with ceramic fiber cloth or alumina fiber cloth (for example, Jikkei 6-18223 or Jikkaihei 2-93698) is proposed. ing.

[0004]

However, in the lining structure in which various coatings are applied to the inner surface of the ceramic fiber heat insulating material layer as described above, shrinkage due to high temperature heating and cracks due to thermal shock occur in the coating layer. The coating layer is easily peeled off to expose the ceramic fiber heat insulating material. In addition, the lining structure in which the ceramic sintered plate is attached to the furnace inner surface of the ceramic fiber heat insulating material layer causes shrinkage of the ceramic sintered plate due to high temperature heating and cracks due to thermal shock, resulting in peeling of the ceramic sintered plate. It is easy to drop or drop it. Thus, the lining structure in which the furnace inner surface of the ceramic fiber heat insulating material layer is coated or the ceramic sintered plate is attached is not sufficient in terms of durability.

On the other hand, in the lining structure in which the furnace inner surface of the ceramic fiber heat insulating material layer is covered with ceramic fiber cloth or alumina fiber cloth,
Although excellent in impact resistance, these cloths are generally breathable, inevitably prevent permeation of reducing gas such as hydrogen gas and alkali, and the protection of the ceramic fiber insulating material is not sufficient.

The present invention has been made in view of the problems of such a conventional lining structure, and has high resistance to reducing gas such as hydrogen gas and alkali, excellent wind speed resistance, and sufficient durability. It is an object of the present invention to provide a furnace wall lining structure having good properties.

[0007]

The furnace wall lining structure of the present invention comprises a heat-resistant inorganic fibrous heat insulating material layer on the furnace inner surface,
The present invention is characterized in that a protective layer made of a ceramics layer reinforced with a heat-resistant inorganic fiber cloth is provided, which makes it possible to solve the above problems. The protective layer in the present invention is, for example, a mixture of ceramic powder and an inorganic binder as a main component and a heat-resistant inorganic fiber cloth that are integrated by lamination molding to form a protective plate, and the protective plate is an assembly of heat-resistant inorganic fibers. It is formed by sticking to the inner surface of the furnace wall of. Further, the protective layer, by fixing the heat-resistant inorganic fiber cloth to the furnace inner surface of the furnace wall at the construction site, and applying a coating material containing ceramic powder and an inorganic binder as the main components on the heat-resistant inorganic fiber cloth surface. It can also be formed by solidifying. Such a coating method is effective for the construction of complicated curved surfaces and corners of the furnace wall.

The heat-resistant inorganic fiber cloth is preferably an alumina fiber cloth which is chemically stable against reducing gas and alkali and is easily available. The heat-resistant inorganic fiber cloth is preferably tightly braided, but is not particularly limited. The ceramic constituting the protective layer is preferably alumina, silicon nitride, silicon carbide, zirconia, or a mixture thereof, which has excellent heat resistance and corrosion resistance. If there is no reducing gas or alkali in the heating furnace and there is no risk of chemical erosion, it is possible to substitute silica stone, refractory viscosity, chamotte, or the like. In the above, the thickness of the heat-resistant inorganic fiber cloth and the layer thickness of the ceramic layer are not particularly limited and are appropriately set according to the design of the heating furnace.

[0009]

In the furnace wall lining structure according to the present invention, the heat-resistant inorganic fibrous heat insulating material layer is provided on the inner surface of the furnace with the protective layer made of the ceramic layer reinforced by the heat-resistant inorganic fiber cloth. The inorganic fiber cloth improves the thermal shock resistance of the protective layer itself and prevents the protective layer from peeling or falling off, so it has excellent wind speed resistance and abrasion resistance, and enhances the reliability of the fiber and shot scattering prevention effect. In addition, the protective layer prevents permeation of reducing gas and alkali in the furnace and protects the heat-resistant inorganic fiber heat insulating material from chemical erosion.

Further, the heat-resistant inorganic fiber cloth used for the protective layer is made of alumina fiber cloth which is chemically stable against reducing gas and alkali, and the ceramics constituting the protective layer is made of alumina excellent in heat resistance and corrosion resistance. Thermal resistance and chemical resistance can be improved by using silicon nitride, silicon carbide, zirconia, or a mixture thereof.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a sectional view of an essential part showing a furnace wall lining structure according to the present invention. As shown in the drawing, a ceramic fiber block 1 formed by stacking and compressing ceramic fiber blankets into a block shape is fixed by a fixing member 3 fixed to an iron shell 2 forming a furnace outer shell. The protective layer 4 is attached to the inner surface of the lining structure. The protective layer 4 is formed by laminating beforehand a mixture of alumina fiber cloth 5, alumina powder and an inorganic binder, and integrating them into a plate shape. The protective layer 4 is fixed to the ceramic fiber block 1 by fixing pins 6.

[0012]

As described above, the lining structure of the furnace wall according to the present invention comprises the ceramic layer reinforced by the heat-resistant inorganic fiber cloth on the surface of the heat-resistant inorganic fiber insulating material layer inside the furnace. It is characterized in that a protective layer is provided. Since the protective layer is composed of a ceramic layer reinforced with a heat-resistant inorganic fiber cloth, the heat-resistant inorganic fiber cloth improves the thermal shock resistance of the protective layer itself and prevents the protective layer from peeling or falling off from the furnace wall. The protective layer prevents permeation of reducing gas and alkali in the furnace and protects the heat-resistant inorganic fibrous heat insulating material layer from chemical erosion.

Further, the heat-resistant inorganic fiber cloth used for the protective layer is made of alumina fiber cloth which is chemically stable against reducing gas and alkali, and the ceramics constituting the protective layer is made of alumina excellent in heat resistance and corrosion resistance. By using silicon nitride, silicon carbide, zirconia, or a mixture thereof, thermal and chemical resistance can be added to the above effects.

Therefore, according to the present invention, since the heat insulation is good and the heat capacity is small, the thermal efficiency of the heating furnace is good, and the characteristics of the lining structure of the furnace wall made of the heat-resistant inorganic fiber having excellent thermal shock resistance are impaired. The lining structure of the furnace wall is excellent in wear resistance and wind speed resistance, enhances the reliability of the effect of preventing scattering of fibers and shots, is not easily attacked by reducing gas or alkali, and has sufficient durability. be able to.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a lining structure of a furnace wall according to the present invention.

[Explanation of symbols]

 1 Ceramics fiber block 2 Iron skin 3 Fixing member 4 Protective layer 5 Alumina fiber cloth 6 Fixing pin

Claims (3)

[Claims] 1. A lining structure for a furnace wall, characterized in that a protective layer made of a ceramics layer reinforced with a heat-resistant inorganic fiber cloth is provided on the furnace inner surface of the heat-resistant inorganic fiber heat insulating material layer. 2. The furnace wall lining structure according to claim 1, wherein the heat-resistant inorganic fiber cloth is an alumina fiber cloth. 3. The furnace wall lining structure according to claim 1, wherein the ceramic layer is made of at least one of alumina, silicon nitride, silicon carbide, and zirconia.