JP3135149B2 - Municipal solid waste incineration ash melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a municipal waste incineration ash melting furnace. A melting furnace that melts municipal solid waste incineration ash with electricity is used. The melting furnace is equipped with electrodes, and an inlet for incineration ash, an exhaust port, an outlet for molten slag, etc. are opened, and the furnace shell is lined with refractory bricks and irregular refractories. . The present invention relates to an improvement of such a municipal waste incineration ash melting furnace.

[0002]

2. Description of the Related Art Conventionally, as a municipal solid waste incineration ash melting furnace, a furnace having a furnace wall lined with refractory bricks has been used. However, in the municipal solid waste incineration ash melting furnace, either a castable or stamp material, which is an amorphous refractory, is cast on the hearth, or a refractory brick is laid flat. As a material for the furnace material, magnesia or high alumina is mainly used. In the prior art, the molten metal and slag penetrate into the amorphous refractory to form a deteriorated layer and cause delamination damage. Also, refractory bricks are constructed flat, and joints are opened due to thermal expansion. A phenomenon occurs in which metal invades from the joint opening and lifts up the whole.

[0003] As a municipal solid waste incineration ash melting furnace, a furnace in which an irregular refractory such as a stamp material or a castable is lined with the furnace wall is also used. However, amorphous refractories tend to be inhomogeneous because they require on-site construction, and have a layered strength difference due to the property of exhibiting sintering strength by heating. In the case of a large furnace, the slag is likely to be generated and the slag is often infiltrated. In the case of a large furnace, the slag may rise due to structural spalling. Further, the molten slag is acidic, and has a drawback that the furnace material used is eroded and worn to shorten its life.

[0004]

The problem to be solved by the present invention is that, in the conventional municipal solid waste incineration ash melting furnace, metal invades from the joint opening of the refractory brick and causes the entire hearth to rise, or An object of the present invention is to provide a furnace material and a structure which are largely eroded and infiltrated in an amorphous refractory, prevent the formation of a deteriorated layer and cause damage due to peeling, and are durable against acidic molten slag.

[0005]

SUMMARY OF THE INVENTION The present invention, which solves the above-mentioned problems, is a melting furnace for melting municipal solid waste incineration ash with electricity, wherein the entire surface of the hearth in contact with the melt in the furnace is an amorphous refractory. Al ₂ O ₃ —Si laid on the whole as an inverted arch
According to municipal solid waste incineration ash melting furnace according to C-based or Al ₂ O ₃ characterized in that it comprises are formed by -SiC-C refractory bricks.

An important point in the present invention is that the refractory brick laid on the irregular-shaped refractory of the hearth is of an Al ₂ O ₃ —SiC type or an Al ₂ O ₃ —SiC—C type, and Except for the runner whose bricks are connected to the molten slag outlet, as a whole,
It is in the place where it has an inverted arch.

The refractory brick used in the present invention is made of Al ₂ O ₃ 5
5 to 65% (weight%, the same applies hereinafter), SiC 35 to 45%
And Al ₂ O ₃ 70-85%, SiC
A composition having a composition of 10 to 20% and C 5 to 10% is preferable. Such Al ₂ O ₃ —SiC or Al ₂ O ₃ —SiC
-C-based refractory bricks are Al ₂ O ₃ -Cr ₂ O ₃ -based or MgO
-Cr compared with ₂ O ₃ refractory brick is small erosion and infiltration by molten slag acidic generating a municipal waste incineration ash in melt processing.

The above Al ₂ O ₃ —SiC or Al ₂ O ₃ —S
The iC-C refractory brick preferably includes the vicinity of the surface of the molten slag, and is preferably lined with a furnace shell portion located below the furnace wall and corresponding to the furnace wall. However, in these Al ₂ O ₃ —SiC and Al ₂ O ₃ —SiC—C refractory bricks, C and SiC in the refractory bricks are oxidized due to furnace gas conditions, oxygen contained in metal and slag. There is concern that it has been vulnerable.
At the beginning of the operation, scrap is charged and dissolved, so FeO,
This is because a large amount of Fe ₂ O ₃ is generated and reacts with C in the refractory brick. As a method of solving this concern, Al ₂ O ₃ —Cr, which is hard to oxidize refractory bricks on the furnace wall surface and further on the hearth surface, and has some corrosion resistance and infiltration resistance to metal and slag. ₂ O ₃ and Al ₂ O ₃ −
It is preferable to cover with a protective wall made of SiO ₂ refractory bricks or irregular refractories.

Table 1 shows the compositions of the metal and slag used in the test. Table 2 shows the erosion depth and infiltration depth due to the molten metal and molten slag when the metal and slag having the composition shown in Table 1 were charged into a furnace in which a refractory brick or castable was lined in the furnace shell and induction-heated at 1550 ° C for 5 hours. This is an example. It can be seen from Table 2 that the Al ₂ O ₃ -SiC-based refractory brick is superior to other refractory bricks, and that the Al ₂ O ₃ -SiC-C-based refractory is superior to other refractory bricks even in irregular shapes. It is clear that there is.

[0010]

[Table 1]

[0011]

[Table 2]

Table 3 shows FeO and Fe ₂ O ₃ dissolved in the initial operation.
The slag composition was tested for the selection of suitable materials for refractories for protective walls in order to prevent the oxygen inside from reacting with C in the refractory bricks. Table 4 shows the lining of refractory bricks or irregular refractories. The slag containing FeO shown in Table 3 is charged into the furnace, and the erosion depth and the infiltration depth when induction heating is performed at 1550 ° C. for 5 hours are illustrated. Table 4 shows that FeO
Al ₂ O ₃ -Cr ₂ O ₃
It is evident that the refractory bricks and monolithic refractory systems and Al ₂ O ₃ -SiO ₂ system is better than Al ₂ O ₃ -SiC system. Therefore, slag containing a large amount of iron oxide may be generated in the early stage of the operation, so that Al ₂ O ₃ —SiC, Al ₂
O ₃ protective wall is effective in adopting -SiC-C refractory bricks.

[0013]

[Table 3]

[0014]

[Table 4]

[0015]

According to the present invention, since the refractory bricks are laid on the irregular-shaped refractory over the entire surface of the hearth in contact with the melt in the furnace as a whole, the refractory bricks are mutually pushed by thermal expansion. Even in this case, the pressing force works in the direction of the lower refractory, and does not rise. Further, no gap is formed between the refractory bricks laid in an inverted arch due to the mutual pressing force due to the thermal expansion, so that the molten metal or the molten slag does not enter between the refractory bricks. Thus, the refractory brick is not lifted. Needless to say, refractory bricks are homogeneous, have smaller pores and air permeability, and have less erosion and infiltration by molten metal or molten slag, as compared with amorphous refractories. For molten slag exhibiting acidity, Al ₂ O ₃
-SiC system and Al ₂ O ₃ -SiC-C system is large tolerability, municipal solid waste incinerator ash melting furnace according to the present invention by employing a protective wall for preventing oxidation wear of C in operation the initial brick It has excellent durability.

[0016]

1 is a longitudinal sectional view schematically showing an embodiment of the present invention. In this embodiment, an incineration ash inlet, an exhaust outlet, a molten slag outlet, and the like are omitted. A furnace lid 12 is attached to the upper part of the furnace body 11 so as to be openable and closable, and the furnace lid 12 is provided with an electrode 21. A stamp material 41 is pressed against the hearth of the furnace shell 31 of the furnace body 11, and an Al ₂ O ₃ —SiC or Al ₂ O ₃
-The refractory brick 51 of the SiC-C system is laid as an inverted arch as a whole. The furnace shell 31 of the furnace body 11 has an Al ₂ O ₃ —SiC or Al ₂ O ₃ —SiC—C
-Based refractory bricks 52 and 61 are lined, and the refractory brick 52 has an Al ₂ O ₃ -Cr ₂ O ₃ -based or Al ₂ O ₃ -Si
A protective wall 71 made of an O ₂ -based refractory is lined. In the illustrated state, the molten metal A in the furnace is in contact with the refractory brick 51 of the hearth, and the molten slag B located above the molten metal A is in contact with the protective wall 71.

FIG. 2 is a longitudinal sectional view schematically showing another embodiment of the present invention. Furnace body 13, furnace roof 14, electrode 22, furnace shell 32, the stamp member 42 and the Al ₂ O ₃ -SiC system or Al
₂ O ₃ interrelationship of -SiC-C based refractory bricks 53,54,62 are made in the same manner as in FIG. 1, in one embodiment of FIG. 2, Al ₂ O refractory brick 53 of the hearth _3- Cr ₂ O ₃
A protective wall 72 made of an amorphous or refractory based on Al ₂ O ₃ —SiO ₂ is lined, and a similar protective wall 73 is lined with the refractory brick 54 of the furnace wall. In the state shown in the figure, the molten metal C in the furnace is in contact with the protective wall 72 of the hearth, and the molten slag D
Is in contact with the protective wall 73 of the furnace wall.

[0018]

As is clear from the above, the present invention described above has an effect of having excellent durability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view schematically showing another embodiment of the present invention.

[Explanation of symbols]

11, 13 ... furnace body, 12, 14 ... furnace lid, 2
1,22 ... electrode, 31,32 ... furnace shell, 41,4
2: stamp material, 51 to 54, 61, 62: refractory brick, 71 to 73: protective wall, A, C: molten metal, B, D: molten slag

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP2-30894 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F23G 5/44 ZAB F23M 5/00

Claims (3)

(57) [Claims] 1. A municipal waste incineration ash A melting furnace for melting processes in an electric, Al ₂ which hearth entirely in contact with the melt in the furnace is installed in the reverse arch shape as a whole on the monolithic refractory O _Three
-SiC system or Al ₂ O ₃ -SiC-C based urban waste incineration ash melting furnace characterized by comprising formed by refractory bricks. 2. The municipal solid waste incineration ash melting furnace according to claim 1, wherein the furnace wall including and below the molten slag is covered with a protective wall. 3. The municipal solid waste incineration ash melting furnace according to claim 1, wherein the furnace wall and the furnace floor including and below the molten slag are covered with protective walls.