JP2002048480A - Furnace wall structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wall structure for a rotary incinerator capable of maintaining the effective stirring of incinerated or molten materials therein and further using erosible refractories for their lifetimes by maintaining the unevenness of the inner surface of the furnace, which unevenness can be formed comparatively mildly on the inner surface of the furnace by employing refractories constituting lifters different in erosivity from those constituting other furnace walls to positively make use of erosivity difference through the use of the furnace for a predetermined period of time. SOLUTION: The wall 1 of the rotary incinerator is composed of two kinds of refractories 2 and 3 different from each other in erosivity, alternately arranged circumferentially and extending longitudinally. The more erosive refractory 2 is about 1.4 times in erosivity than the less erosive refractory 3. Both the refractories 2 and 3 contain Al2O3 as a main constituent and Cr2O3, and the content of the latter causes the erosivity difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a furnace wall structure of a furnace such as a refuse incinerator, an ash melting furnace, a melting kiln and a gasification melting furnace.

[0002]

2. Description of the Related Art For example, in a rotary incinerator or the like, as shown in FIG.
(21) A plurality of inward protrusions called lifters (22) are provided on the inner surface at predetermined intervals in the circumferential direction so as to extend in the length direction. Conventionally, the refractory constituting the lifter (22) is of the same type as the refractory (23) constituting the other furnace walls,
When the incinerator has been used for a long period of time, as shown in FIG. 4 (b), the lifter (21) is often worn and the unevenness on the inner surface disappears, and the stirring ability often decreases.

[0003]

SUMMARY OF THE INVENTION In view of the above points, the present invention provides (1) a method in which a refractory constituting a lifter has a different erosion property from other refractories constituting a furnace wall. Positively utilizing the difference in gender, unevenness is formed on the furnace inner surface relatively gently by using it for a certain period of time. (2) By keeping this unevenness for a long period of time, the incineration and melting It is an object of the present invention to provide a furnace wall structure in a rotary furnace which can maintain stirring and can be used for the life of a refractory which is easily eroded.

[0004]

A furnace wall structure according to the present invention is characterized in that a plurality of types of refractories having different erosion properties are alternately or sequentially arranged in the circumferential direction.

In such a furnace wall structure, two types of refractories having different erosion properties are alternately arranged, and the erosion property of one refractory is 1.2 times or more that of the other refractory. Some are particularly preferred.

[0006] A preferred refractory is one containing Al ₂ O ₃ as a main component and containing Cr ₂ O _3.
The erodibility differs depending on the difference in the content of ₂ O ₃ .

Another preferred furnace wall structure is characterized in that the inner surface area of the refractory which is easily eroded is smaller than the inner surface area of the refractory which is hardly eroded on the inner surface of the furnace wall.

The furnace wall structure according to the present invention is suitably used in rotary incinerators such as refuse incinerators, ash melting furnaces, melting kilns and gasification melting furnaces.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention.

Embodiment 1 In FIG. 1 (a), two types of refractories having different erosion properties (2) and (3) are formed in a furnace wall (1) of a rotary incinerator in a circumferential direction. They are arranged alternately and extend in the length direction. The erodibility of one refractory (2) which is susceptible to erosion is about 1.4 times that of the other refractory (3) which is hard to erode. All refractories (2) and (3) are Al ₂ O
₃ is a refractory material containing the main component Toshikatsu _Cr 2 _{O 3,} and erodible by difference in the content of _Cr 2 _{O 3} are different.

As a result of using the rotary incinerator having the above configuration for a certain period of time, as shown in FIG.
The inner surface of (2) gradually erodes, and irregularities are formed on the inner surface of the furnace.

[0012] In the corrosion resistance test Figure 2, the furnace wall of the rotary erosion test specimen having a diameter of _{300mm (6), Cr 2 O} 3 Al 2 O 3 containing 10 wt%
Brick (4) and Al ₂ containing 30 wt% of Cr ₂ O ₃
O ₃ bricks (5) is one that is provided extending in the arranged longitudinally alternately in the circumferential direction. The radial thickness of each brick is about 60 mm.

The weight ratio of Na in the space inside the test piece (4)
₂ O 7%, Al ₂ O ₃ 8%, SiO ₂ 3
3.5%, CaO 33.5%, Fe ₂ O ₃ 18
% Of the slag (8), and while rotating the specimen (4) on a roller, the inner surface of the specimen (6) was
Heat at 0 ° C. for 50 hours with burner (7).

As a result, the erosion amount of the brick (4) is 14 mm,
The amount of erosion of the brick (5) was 2.5 mm.

From these results, when the furnace is used for a certain period,
It can be seen that the inner surface of the refractory (4), which is susceptible to erosion, is gradually eroded, and irregularities are formed on the inner surface of the furnace, whereby the stirring effect can be maintained for a long time.

In the case where the replacement period of the brick is long, a combination of refractory materials having a small difference in erosion may be adopted. In the case where irregularities are to be formed in the furnace in a short time, the difference in erosion is small. A combination of large refractories may be used.

Embodiment 2 In FIG. 3, the refractories constituting the furnace wall (9) of the arch furnace have two types of refractories having different shapes and different erosion properties.
(10) and (11) are arranged alternately in the circumferential direction and are provided extending in the length direction. That is, one refractory (10) that is easily eroded is the other refractory (11) that is less likely to be eroded.
In comparison with the above, the shape has a shape such that the thickness in the circumferential direction gradually decreases and the surface area in the furnace decreases as going in the furnace direction. By providing a difference in the furnace surface area in this way,
The amount of erosion can be adjusted. The outer surface of the furnace wall (9) is steel
Covered in (12).

In addition, different shapes and different erosion properties 2
Since these types of refractories (10) and (11) have different rigidities,
There is also an effect of reducing the generated stress.

[0019]

Since the present invention is configured as described above, the following effects can be obtained.

(1) The refractory constituting the lifter has a different erodibility from the other refractories constituting the furnace wall. Irregularities can be formed relatively mildly on the inner surface.

(2) By keeping these irregularities for a long period of time, effective stirring of the incinerated material and the melt in the rotary furnace can be maintained.

(3) It can be used up to the life of a refractory which is easily eroded.

[Brief description of the drawings]

1 is a cross-sectional view showing a part of a furnace wall of a rotary incinerator, in which FIG. 1 (a) shows a state before use and FIG. 1 (b) shows a state after use for a certain period.

FIG. 2 (a) is a perspective view showing a rotary erosion test specimen, and FIG. 2 (b) is a transverse sectional view thereof.

FIG. 3 is a cross-sectional view showing a part of a furnace wall of an arc furnace.

FIG. 4 is a cross-sectional view showing a part of a furnace wall of a conventional rotary incinerator. FIG. 4 (a) shows a state before use, and FIG. 4 (b) shows a state after use for a certain period.

[Explanation of symbols]

(1): furnace wall of the rotary incinerator (2): eroded easily refractory (3): eroded hard refractory _{(4): Cr} 2 O 3 _Al 2 _{O 3} containing 10 wt%
Bricks _{(5): Cr 2 O 3} Al 2 O 3 containing 30 wt%
Brick (6): Rotating erosion test specimen (8): Slag (9): Furnace wall of arched furnace (10): Refractory that is easily eroded (11): Refractory that is hard to be eroded

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 1/00 F27D 1/00 D (72) Inventor Jun Yano 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi No. Date Tate Shipbuilding Co., Ltd. F-term (reference) 3K065 AA07 AB01 AB03 AC01 4K051 AA00 AB03 BB02 BB07 DA06 DA13 DA18 4K061 AA08 BA12 CA17

Claims (5)

[Claims] 1. A furnace wall structure wherein a plurality of types of refractories having different erosion properties are alternately or sequentially arranged in a circumferential direction. 2. The method according to claim 1, wherein two types of refractories having different erosion properties are alternately arranged, and the erosion property of one refractory is 1.2 times or more the erosion property of the other refractory. Item 2. A furnace wall structure according to item 1. 3. are those refractory contains a main component Toshikatsu _Cr 2 _{O 3} and _{Al 2 O 3, Cr 2 O} 3
3. The furnace wall structure according to claim 1, wherein the erodibility differs depending on the difference in the content of slag. 4. The furnace wall structure according to claim 1, wherein an inner surface area of the refractory which is easily eroded on the inner surface of the furnace wall is smaller than an inner surface area of the refractory which is hardly eroded. 5. A rotary incinerator having the furnace wall structure according to claim 1.