JP2008128525A - Construction method of bottom wall of gasification melting furnace, precast block for bottom wall, and combination unit of precast block for bottom wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction method of a bottom wall of a gasification melting furnace, a precast block for the bottom wall, and a combination unit of the precast block for the bottom wall, capable of completing the bottom wall early without needing a time in constructing the bottom wall of the gasification melting furnace, forming the precise bottom wall, and elongating its service life. <P>SOLUTION: When the plurality of precast blocks 24-26 are combined in a line, each of recessed portions 24b, 25b, 26b and a groove 26d are arranged along the line direction (melt flowing direction), and a flow channel for the melt is formed by the recessed portions 24b, 25b, 26b and the groove 26d. Faces of the precast blocks 24-26 having faces (joining faces 24d, 25e, 25d, 26f) joined to each other when the plurality of precast blocks 24-26 are combined, are formed along the direction orthogonal to the flow channel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a construction method for a bottom wall of a gasification melting furnace for treating municipal waste, industrial waste, and the like, a precast block for the bottom wall, and a combination unit of the precast block for the bottom wall.

  Conventionally, municipal waste, industrial waste, and the like are incinerated at a waste disposal site to reduce the volume, and solid matter such as incineration residue that is finally discharged is landfilled at a landfill site. In addition, the fly ash generated when incinerated or melted in these solids contains heavy metals such as zinc and lead, so the fly ash is stabilized by cement solidification, chemical treatment, etc. After being landfilled. However, such disposal requires a landfill site and in recent years it has become very difficult to secure such a site. In addition, even when stabilized, there is a risk that heavy metals eluted from landfilled fly ash will cause environmental pollution in the ultra-long term, and it is necessary to take measures to prevent environmental pollution. is there.

  For this reason, in recent years, as a method for treating waste instead of the incineration treatment, heat treatment of the waste is performed in a reducing heat treatment furnace. As an example of such a processing method, there is a gasification melting process by a gasification reforming method (see Patent Document 1).

In this method, the waste is heat-treated in a gasification melting furnace to convert the waste into a gas containing a pyrolysis gas and a melt. And this gasification melting method has an advantage that there are few harmful gas components, such as dioxin, in the obtained gas. In addition, since the pyrolysis gas generated from the waste contains a combustible gas, this gas can be effectively used as a fuel for power generation, a fuel for industrial use, a raw material for chemical industry, and the like. Furthermore, since harmful substances such as heavy metals contained in the waste can be fixed in the molten slag, there is an advantage that the heavy metals are hardly eluted.
JP 2005-249366 A

  By the way, in the gasification melting furnace, since the temperature inside the furnace body becomes high and comes into contact with high-temperature gas or molten slag, the furnace body generally has a structure in which the outer iron shell is lined with a refractory. Yes. When forming the bottom wall of the bottom (furnace bottom) of the gasification melting furnace, conventionally, castables are molded and formed on the bottom at the site where the gasification melting furnace is provided. .

  However, if the bottom wall is castable at the site where the gasification melting furnace is installed, the construction time for forming the bottom wall becomes long, and there is a problem that the efficiency is low and the construction cost of the gasification melting furnace is high. was there. In addition, when the bottom wall is castable at the site, it is necessary to increase the fluidity of the castable, so the amount of water used increases, making it difficult to form a dense (high density) bottom wall. There was a low problem.

  The present invention does not require time for the construction of the bottom wall of the gasification melting furnace, and can complete the bottom wall at an early stage, and can be formed into a dense bottom wall, which can increase the service life. An object of the present invention is to provide a method for constructing a bottom wall of a furnace, a precast block for the bottom wall, and a combination unit of the precast block for the bottom wall.

  To achieve the above object, the invention according to claim 1 is characterized in that a bottom wall is constructed by arranging a precast block made of an irregular refractory material at the bottom of a gasification melting furnace. The gist of the construction method of the bottom wall of the melting furnace.

  In the invention of claim 2, a plurality of precast blocks made of amorphous refractory are arranged in a row along the direction in which the melt flows with respect to the bottom of the gasification melting furnace, and the joints between the precast blocks are arranged in the row. The gist of the construction method of the bottom wall of the gasification melting furnace is to form the bottom wall by forming it in a direction perpendicular to the direction in which the melt flows.

  The gist of the invention of claim 3 is a precast block for a bottom wall of a gasification melting furnace, which is made of an irregular refractory and has a channel recess for flowing a melt on its upper surface. Is.

  A fourth aspect of the present invention is a combination unit of a plurality of bottom wall precast blocks made of an indefinite shape refractory and having a channel recess for flowing a melt on the upper surface. When the precast blocks for walls are combined in a row, the flow passage recesses are arranged along the row direction, and flow channels through which the melt flows are formed by the flow passage recesses, The surface of the bottom wall precast block having surfaces joined together when the precast blocks are combined in a row is formed along a direction perpendicular to the flow path. The gist of the present invention is a combined unit of precast blocks for the bottom wall of a chemical melting furnace.

  According to the first aspect of the present invention, since the bottom wall precast block molded in the factory can be constructed as the bottom wall by placing it at the bottom of the gasification melting furnace, it takes time to construct the bottom wall of the gasification melting furnace. Without any effect, the bottom wall can be completed early. In addition, when forming a precast block at a factory, the amount of water used can be controlled to form the precast block, so that a dense (high density) precast block can be formed, and as a result, the durability of the bottom wall is increased. be able to.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the joints between the precast blocks are formed in a direction orthogonal to the direction in which the melt flows. Melting loss can be suppressed. That is, if the joint is arranged along the flow direction with the high-temperature melt, the amount of erosion increases because the joint is exposed to the melt so as to follow the flow of the high-temperature melt. In the invention of item 2, such a situation does not occur, and melting damage of joints can be suppressed.

  According to the invention of claim 3, since the precast block for the bottom wall which can expect the effect of claim 1 can be provided and the flow path recess is provided, when the bottom wall of the gasification melting furnace is formed, The melt can easily flow through the channel recess.

  According to invention of Claim 4, the precast block for bottom walls which can anticipate the effect of Claim 1 and the effect of Claim 2 can be provided.

Hereinafter, an embodiment in which the present invention is embodied in a bottom wall of a gasification melting furnace will be described with reference to FIGS.
FIG. 1 is a schematic sectional view of a gasification melting furnace. First, the outline and function of the basic configuration of this gasification melting furnace will be described. The gasification melting furnace 10 has a cylindrical high-temperature reactor 12 at the top and a homogenization furnace 14 at the bottom. As shown in FIG. 1, the homogenizing furnace section 14 is formed extending in the lateral direction from the furnace bottom 15, and a discharge port 16 is provided at the lower end of the terminal. Further, on the side wall in the vicinity of the furnace bottom 15, as shown in FIG. 1, a lance 17 for introducing high-concentration oxygen into the furnace and auxiliary fuel (liquid fuel such as pulverized coal and heavy oil, or gas such as natural gas). A lance 18 for introducing fuel is provided.

  In the gasification melting furnace 10, wastes such as municipal waste and industrial waste are compressed by a press machine (not shown), and then heated and dry-distilled by indirect heating in a dry pyrolysis process to form a dry-distilled product. Then, it is sent to the high temperature reaction furnace section 12 through the inlet 12a provided at the lower part of the high temperature reaction furnace section 12. A lance 13 is disposed below the high temperature reactor 12. The lance 13 introduces high-concentration oxygen into the furnace, and this oxygen gas reacts with carbon in the dry distillation product to generate carbon monoxide and carbon dioxide. Further, since high-temperature steam is present in the furnace, a water gas reaction occurs between carbon and steam, and hydrogen and carbon monoxide are generated. Further, organic compounds (such as hydrocarbons) also react with water vapor to produce hydrogen and carbon monoxide. As a result of the above reaction, the crude synthesis gas is recovered through a gas discharge port (not shown) provided at the top of the high-temperature reactor 12.

  On the other hand, the melt produced in the lower part of the high temperature reactor 12 flows out from the high temperature reactor 12 to the homogenizer 14. This melt contains carbon, a trace amount of heavy metal, and the like, and in the homogenization furnace section 14, carbon is gasified with sufficient oxygen or water vapor to generate hydrogen, carbon monoxide, and carbon dioxide. In the homogenization furnace section 14, the metal melt has a large specific gravity and therefore accumulates in the lower part of the slag. The melt is discharged from the discharge port 16 and flows down to a not-shown granulation system, and is cooled and solidified. The metal / slag mixture is separated into metal and slag by magnetic separation.

  The crude synthesis gas generated from the high-temperature reactor 12 is rapidly cooled from about 1200 ° C. to about 70 ° C. by acid water being injected by a quenching device (not shown) to re-synthesize dioxins. Is blocked. At this time, the acid is washed with acid water, and heavy metal components such as Pb and chlorine contained in the crude synthesis gas are dissolved during the washing.

  The acid-cleaned synthesis gas is further subjected to acid cleaning if necessary, and then alkali-cleaned, and the remaining acidic gas such as hydrogen chloride gas is neutralized and removed. Next, hydrogen sulfide in the gas is converted to sulfur by a desulfurization washing apparatus (not shown) and recovered as a sulfur cake. Next, the synthesis gas is used as a refined fuel gas after moisture is removed in a low temperature dehumidification process.

Now, in the gasification melting furnace 10 used as described above, the bottom part of the homogenization furnace part 14 located immediately below the high temperature reaction furnace part 12 will be described.
At the bottom of the homogenization furnace section 14 located directly below the high temperature reactor section 12, a plurality of bottom wall precast blocks as a precast block for the bottom wall with respect to the upper surface of the amorphous refractory 22 lined on the inner bottom surface of the iron skin 20 are provided. The bottom wall is constructed by arranging the precast blocks 24 to 26 in a line. The precast blocks 24 to 26 are prepared by kneading a refractory aggregate of various sizes to which a predetermined amount of water is added and a cast amorphous refractory with a kneader, and transferring the hopper from the kneader to the hopper. It is formed by being poured into a space formed by a mold. The raw materials used for the precast blocks 24 to 26 are not limited to materials as long as they are rich in corrosion resistance. Examples of the alumina amorphous refractories rich in corrosion resistance include alumina amorphous refractories, and these alumina-based amorphous refractories preferably contain magnesia or chromia imparting high corrosion resistance. . In this embodiment, the raw material used for the precast blocks 24-26 is an alumina-chromia-based raw material.

  As shown in FIG. 3, the precast block 24 is formed in a shape in which a truncated cone whose upper half is inverted up and down is divided in half along the axial direction, and the upper half is divided in half along the axial direction. It is formed in the shape. As shown in FIGS. 1 and 3, a part of the upper surface of the precast block 24 is formed with a joining surface 24 a having a flat surface and joined to an indeterminate refractory 14 a lined on the inner surface of the iron skin 20. . On the upper surface of the precast block 24, a recess 24b serving as a channel recess is formed in the portion excluding the joint surface 24a. The recess 24b is formed in a cross-sectional arc shape in the width direction (a direction orthogonal to the direction A (see FIG. 3) in which the melt flows), and has a cross section as shown in FIGS. 1 and 3 toward the direction A in which the melt flows. The arcuate deepest part is formed so as to gradually become deeper. As shown in FIGS. 1 and 3, the lower end surface of the precast block 24 has a horizontal surface 24c.

  Further, the lower half of the precast block 25 provided adjacent to the precast block 24 is provided with a uniform thickness in the direction A (see FIG. 3) in which the melt flows. Further, as shown in FIGS. 1 and 3, a joint surface 25 a having a flat surface is formed at the upper part of both ends in the width direction of the precast block 25, and the amorphous refractory 14 a lined on the inner surface of the iron skin 20 is formed. It is joined. The joining surface 25a has the same height as the joining surface 24a and is formed in a plane.

  On the upper surface of the precast block 25, a recess 25b as a channel recess is formed in a portion excluding the joint surface 25a. The recess 25b is formed in a substantially arc shape in cross section so as to communicate with the recess 24b, and as the melt flows in the direction A, the deepest portion of the arc shape in the cross section gradually increases as shown in FIGS. It is formed to be deep. As shown in FIGS. 1 and 3, the lower end surface of the precast block 25 has a horizontal surface 25c.

  Further, as shown in FIG. 3, a joining surface 26 a having a flat surface is formed on the upper portion of both ends in the width direction of the precast block 26 provided adjacent to the precast block 25, and is lined on the inner surface of the iron skin 20. It is joined to the irregular refractory 14a. The joining surface 26a has the same height as the joining surface 25a and is formed in a plane.

  On the upper surface of the precast block 26, a portion other than the joint surface 26a is formed with a recess 26b as a channel recess. The recess 26b is formed in a substantially arc shape in cross section so as to communicate with the recess 25b. Further, as shown in FIG. 3, a groove 26d having a V-shaped cross section as a channel recess is formed in the recess 26b. The deepest part of the groove 26d is formed so as to gradually become deeper in the direction A in which the melt flows. As shown in FIG. 1, the lower end surface of the precast block 25 has a horizontal surface 26c.

  And the joint surfaces 24d and 25e are formed in the mutually opposing surface of the precast blocks 24 and 25 so that it may become substantially parallel, respectively. In addition, joint surfaces 25d and 26f are formed on the surfaces of the precast blocks 25 and 26 facing each other so as to be substantially parallel to each other. Further, a joint surface 26g is formed on the surface opposite to the joint surface 26f of the precast block 26 in parallel with the joint surface 26f, and the refractory brick layer 28 disposed on the upper surface of the amorphous refractory 22 is formed. It is joined. Further, between the joint surfaces 24d and 25e of the precast blocks 24 and 25 and the mutually opposing surfaces of the precast blocks 25 and 26 are filled with the irregular refractory 30 as joints. The amorphous refractory 30 constituting the joint is formed along a direction orthogonal to the direction A in which the melt flows. Moreover, in the precast block 24, between the surfaces facing the iron skin 20, as shown in FIG. In this embodiment, the combination unit of the precast block for bottom walls is comprised by the precast blocks 24-26.

Now, the construction method of 24-26 which comprises the furnace bottom 15 of the gasification melting furnace 10 comprised as mentioned above is demonstrated.
First, in the bottom part of the homogenization furnace part 14 located just under the high temperature reaction furnace part 12, the upper surface of the amorphous refractory 22 is leveled and the space area where the precast blocks 24 to 26 are arranged and the surrounding space. It is assumed that the area is secured in advance. And the combination unit of the precast blocks 24-26 previously formed in the factory with respect to the upper surface of the said irregular-shaped refractory 22 is mounted in the line form along the direction A with which a melt flows. And the joining surfaces 24d and 25e and the joining surfaces 25d, 26f, and 26g of the precast blocks 24-26 are arrange | positioned along the direction (width direction) orthogonal to the direction A through which a melt flows. And between the joint surfaces 24d and 25e, and between the joint surfaces 25d and 26f, the amorphous refractory 30 is filled, respectively, to form joints. Further, the refractory bricks constituting the refractory brick layer 28 are arranged on the joint surface 26 g of the precast block 26 while filling the amorphous refractory 32 between the precast block 24 and the iron skin 20. The amorphous refractory 14a is joined to the joining surfaces 24a, 25a, 26a which are the upper surfaces of the precast blocks 24-26.

Now, the effect of this embodiment will be described.
(1) In the construction method of the bottom wall of the gasification melting furnace of the present embodiment, the bottom wall is constructed by disposing the precast blocks 24 to 26 made of amorphous refractories on the bottom of the gasification melting furnace 10. I did it. As a result, the bottom wall can be completed early without requiring time for the construction of the bottom wall of the gasification melting furnace 10. Furthermore, when forming a precast block at a factory, the amount of water used can be controlled to form the precast block, so that a dense (high density) precast block can be formed, and as a result, the durability of the bottom wall is increased. be able to.

  (2) In this embodiment, in the construction method of the bottom wall of the gasification melting furnace, a plurality of precast blocks made of an amorphous refractory along the direction A in which the melt flows with respect to the bottom of the gasification melting furnace 10. 24-26 were arranged in a line. Then, joints between the precast blocks 24 and 25 and between the precast blocks 25 and 26 are formed in a direction perpendicular to the direction A in which the melt flows to construct the bottom wall. As a result, it is possible to suppress joint damage due to the high-temperature melt.

  (3) The precast blocks 24 to 26 of the present embodiment are formed of an irregular refractory, and the upper surface has recesses 24b, 25b, 26b (flow channel recesses) and grooves 26d (flow channel recesses) for flowing the melt. Is formed. As a result, since the recesses 24b, 25b, 26b (flow channel recesses) and the grooves 26d (flow channel recesses) are provided, when the bottom wall of the gasification melting furnace 10 is formed, the recesses 24b, 25b, 26b ( The melt can easily flow through the channel recesses) and the grooves 26d (channel recesses).

  (4) In the unit of the present embodiment, when the plurality of precast blocks 24 to 26 are combined in a row, the concave portions 24b, 25b, 26b and the grooves 26d are arranged in the row direction (that is, the direction A in which the melt flows). The flow path through which the melt flows is formed by the recesses 24b, 25b, 26b and the groove 26d. The surfaces of the precast blocks 24 to 26 having surfaces (joint surfaces 24d, 25e, 25d, 26f, etc.) that are joined together when the plurality of precast blocks 24 to 26 are combined in a row form the flow path. It was made to form along the direction orthogonal to. As a result, the effects (1) and (2) can be easily realized.

In addition, this invention is not limited to the said embodiment, You may change as follows.
The shape of the precast blocks 24 to 26 is not limited to the above embodiment, and may be a shape corresponding to the bottom of the furnace.

O The shape of the recesses 24b and the like is not limited to a circular arc shape in section, and it goes without saying that the shape is appropriate for posting.
The number of precast blocks constituting the combination unit is not limited to three in the above embodiment, but may be two, or four or more.

  In the precast block 26, the groove 26d may be omitted leaving the recess 26b.

The schematic sectional drawing of the shaft type gasification melting furnace of one embodiment. The schematic sectional drawing of the bottom part of a gasification melting furnace similarly. The perspective view of the unit of the precast block for bottom walls similarly.

Explanation of symbols

A: direction in which the melt flows, 10 ... gasification melting furnace, 15 ... furnace bottom,
24-26 ... Precast block (precast block for bottom wall),
24b ... concave portion (channel concave portion), 25b ... concave portion (channel concave portion),
26b: recess (flow channel recess), 26d: groove (flow channel recess).

Claims (4)

  A method for constructing a bottom wall of a gasification melting furnace, wherein a bottom wall is constructed by arranging a precast block made of an irregular refractory material at the bottom of the gasification melting furnace.   With respect to the bottom of the gasification melting furnace, a plurality of precast blocks made of amorphous refractories are arranged in a row along the direction in which the melt flows, and the direction in which the melt flows through the joints between the precast blocks A method for constructing a bottom wall of a gasification melting furnace, characterized in that the bottom wall is constructed by forming in an orthogonal direction.   A precast block for a bottom wall of a gasification melting furnace, which is made of an irregular refractory and has a channel recess for flowing a melt on its upper surface. The upper surface is a combination unit of a plurality of precast blocks for a bottom wall formed of an irregular refractory and a flow path recess for flowing a melt,
When the plurality of bottom wall precast blocks are combined in a row, the flow passage recesses are arranged along the row direction and a flow path through which the melt flows is formed by the flow passage recesses,
When the plurality of bottom wall precast blocks are combined in a row, the surfaces of the bottom wall precast blocks are formed along a direction perpendicular to the flow path. A combined unit of precast blocks for the bottom wall of a gasification melting furnace.

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