JP2010216781A - Waste disposal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste disposal device capable of elongating a useful life of a furnace wall of a gas reforming furnace. <P>SOLUTION: In this waste disposal device having a gasification melting furnace 5 for partially oxidizing-gasifying, and melting the waste, and the cylindrical gas reforming furnace 5b having an oxygen-containing gas supply opening 44 disposed in a state of being connected with an upper section of the gasification melting furnace, and reforming the gas produced in the gasification melting furnace, a gas duct 40 for discharging the gas from the gas reforming furnace is disposed on a top peripheral wall of the gas reforming furnace, one of conditions that the direction of the gas duct on a horizontal cross-section of the gas reforming furnace is (A) the tangential direction and is (B) the direction deflecting at a prescribed angle to the direction toward a position of the top peripheral wall disposed in the gas duct, from a center of the gas reforming furnace, and swirl flow is formed in the gas reforming furnace. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a waste treatment apparatus that gasifies and melts waste, and relates to a waste treatment apparatus that can extend the useful life of a furnace wall of a gas reforming furnace.

  Currently, the shortage of waste disposal sites is becoming prominent, and most of industrial waste and general waste are in landfills after being incinerated or reduced in volume as they are generated or after some pretreatment. Often, final disposal is performed. There are various methods for the incineration treatment described above. In recent years, management of harmful substances such as dioxins in the gas generated in incineration has become a problem, and it is possible to decompose harmful substances in a high-temperature oxidizing atmosphere. Is required.

  Examples of the waste treatment method capable of such high-temperature treatment include the waste treatment processes disclosed in Patent Documents 1 to 4. The above-mentioned process is a waste treatment process in which waste is compression-molded, dried, pyrolyzed, carbonized, the produced carbonized product is burned, and the incombustible component is melted to obtain fuel gas, slag, and metal. .

FIG. 5 is a side sectional view showing an example of a conventional waste treatment facility.
In FIG. 5, 1 is a compression device that pressurizes and compresses waste batchwise (batch), 2 is a compression piston, 3 is a compression support board, 4 is compressed waste (compressed waste) (hereinafter referred to as “compressed waste”). Horizontal tunnel heating furnace (hereinafter also referred to as tunnel-type heating furnace) for drying and pyrolyzing the compression molded product), 4a is a drying region of the compression molded product, 4b is a thermal decomposition region of the compression molded product, 4e is an inlet of the tunnel-type heating furnace 4, 4f is an inlet of a compression molding provided on the side wall of the high-temperature reactor 5 (: outlet of the tunnel-type heating furnace 4), and 5 is a vertical high-temperature reactor (the upper part is a gas reformer). The material furnace 5a, the lower part is a gasification and melting furnace 5b), 6a and 6b are heating high-temperature gas flow pipes disposed in the side walls of the tunnel heating furnace 4, 10a and 10i are compression moldings, 11i and 11n, respectively. Is a dried compression molding, 12 is dried and pyrolyzed Deposited layer of waste 11 (hereinafter also referred to as a waste deposited layer), 14 is a melt, 14H is a melt outlet, and 15 is an oxygen-containing gas supply pipe for supplying an oxygen-containing gas to the lower part of the gasification melting furnace 5b. 15a is an oxygen-containing gas supply port, 16 is a horizontal cylindrical heating furnace connected to the lower side wall of the high-temperature reactor 5, a melt heating / warming furnace, 16e is an inlet of the melt heating / warming furnace, 17 is Combustion gas supply device (burner) for supplying high-temperature combustion gas into the melt heating / heat-retaining furnace, 18 is an oxygen-containing gas supply pipe for supplying oxygen-containing gas to the gas reforming furnace 5a, and 19 is from the gas reforming furnace 5a. A gas duct for discharging the reformed gas, 20 is a waste inlet, 21 is a lid of the waste inlet, 30 is a quenching device for the high-temperature reactor generated gas discharged from the high-temperature reactor 5, 31 is a gas purifier, 32 Is the reformed gas outlet of the gas reforming furnace 5a, 33 The purified gas, _{f 1} is compression molded product 10a, 10i moving direction of, _{f 2} is dried compression molded product 11i, 11n moving direction of, _{f 3} is the flow direction of the pyrolysis gas produced in a tunnel type heating furnace 4 , F ₄ is the direction in which the oxygen-containing gas is blown into the high temperature reactor 5, f ₅ is the direction of movement of the compression piston 2, f ₆ is the direction of movement of the compression support board 3, and f ₇ is the lid of the waste inlet 20. 21 shows the direction of rotation.

  In the waste treatment facility shown in FIG. 5, first, a predetermined amount of waste supplied from the waste inlet 20 into the compression apparatus 1 is compressed batchwise to form a compact compression molded product 10a. . Next, the compression molded product 10a is pushed into the elongated tunnel type heating furnace 4 heated from the outside.

  The cross-sectional shape of the compression molded product 10a is the same shape and the same size as the cross section of the inner wall of the inlet 4e of the tunnel-type heating furnace 4, and the compression molded product 10a is pushed in while being kept in contact with the inner wall of the tunnel-type heating furnace 4. The atmosphere inside the heating furnace can be sealed at the entrance of the tunnel-type heating furnace. The compression molded product 10i moves while sliding in the tunnel-type heating furnace 4 each time a new compression molded product is sequentially pushed.

  As described above, the tunnel-type heating furnace 4 is heated from the outside, and the temperature inside is increased to about 600 ° C. In the process of moving and raising the temperature of the compression molded product 10 i, moisture and volatile matter in the compression molded product 10 i are increased. Evaporated, volatilized, dried and pyrolyzed. The dried and pyrolyzed compression molded product 11n and the pyrolysis gas generated by the thermal decomposition enter the high temperature reaction furnace 5 maintained at 1000 ° C. or higher from the compression molded product inlet 4f provided on the side wall of the high temperature reaction furnace 5. Charged and supplied.

  The dried and pyrolyzed compression molding 11n supplied into the high-temperature reactor 5 is dried and pyrolyzed in the lower layer (gasification melting furnace 5b) of the high-temperature reactor 5 (deposited waste). A deposited layer 12) is formed. The oxygen-containing gas is supplied into the waste accumulation layer 12 from the oxygen-containing gas supply port 15a provided in the lower part of the gasification melting furnace 5b, and combustible materials such as pyrolytic carbon of the waste 11 are burned, and the thermal energy thereof. Then, the waste 11 is further partially oxidized and gasified, and the incombustible components (metal, ash, etc.) in the waste 11 are melted to produce a melt 14. In the melt heating / insulating furnace 16 connected to the lower side wall of the high-temperature reactor 5, the melt 14 is heated with a high-temperature combustion gas supplied from a combustion gas supply device 17 such as a burner, and a trace amount contained in the melt. The carbon 14 and the like are gasified and removed, and the melt 14 is discharged as molten slag and molten metal from the melt outlet 14H.

  The pyrolysis gas charged into the high-temperature reactor 5 from the tunnel heating furnace 4 and the gas generated from the waste deposition layer 12 of the gasification melting furnace 5b are the upper part of the high-temperature reactor 5 (gas reforming furnace 5a). ), An oxygen-containing gas is supplied from the oxygen-containing gas supply port 18 and a part thereof is combusted, and is retained for 2 seconds or more in a region where the gas temperature is set to 1200 ° C. or higher, and cracking of tar is performed. After reforming to a gas mainly containing carbon oxide, hydrogen, water vapor, and carbon dioxide, it is discharged from the reformed gas discharge port 32 at the top of the furnace to the gas duct 19, cooled in the quenching device 30, and purified in the gas purifying device 31. Then, it is recovered as purified gas 33 for fuel.

  In the gasification melting furnace and gas reforming furnace, the furnace temperature becomes high, so the furnace body has a structure in which the outer iron skin is lined with a refractory. In a gas reforming furnace, the refractory on the furnace wall is in contact with high-temperature gas, so consumption due to erosion is severe. If the refractory is consumed, it is necessary to stop the operation and repair the refractory. However, if frequent repairs are required, the operating efficiency of the processing equipment will decrease and processing costs will increase, so the service life of the refractories on the gas reforming furnace wall will be extended to reduce the frequency of repairs. It is necessary.

In Patent Document 5, pyrolysis gas is blown from the top of the reforming furnace, oxygen is blown into a plurality of stages in the height direction of the reforming furnace side wall, and steam is reformed together with the first stage oxygen from above. It is a gasifying agent that promotes the reforming reaction by introducing a combustion flame at a position farther from the furnace wall than the conventional burner system by introducing it so as to form an oblique downward swirling flow in the furnace. It is described that water vapor is concentrated and blown from the first stage oxygen nozzle to mitigate a rapid temperature rise due to oxygen combustion of the pyrolysis gas and suppress nozzle wear and furnace wall wear.
Further, in Patent Document 6, in a vertical reforming furnace, oxygen gas is supplied into the furnace by an oxygen supply nozzle that is eccentric by 30 degrees or less from the center to the horizontal direction, and a swirling flow is generated in the furnace. Describes that the gas to be reformed and oxygen are mixed uniformly to make the temperature of the reforming section uniform and to reduce the damage to the refractory of the reforming section.
However, the above-described method is still not sufficient to avoid damage to the refractory.

JP-A-6-26626 JP-A-6-79252 JP-A-7-323270 Japanese Patent Laid-Open No. 11-218313 JP 2004-277647 A JP 2006-112714 A

  In order to solve the above-described problems, the present invention is a waste treatment apparatus that partially oxidizes, gasifies, and melts waste, and is capable of extending the useful life of a furnace wall of a gas reforming furnace. An object is to provide a processing apparatus.

As a result of diligent investigation to extend the useful life of the furnace wall of the gas reforming furnace, the present inventors have determined that the direction of extracting the reformed gas from the gas reforming furnace is a specific direction. It is possible to prolong the service life of the refractory without excessively high temperature gas coming into contact with the refractory surface, and at the same time, the tip position and direction of the oxygen-containing gas supply port to the gas reforming furnace The present invention has been completed by finding that the service life of the refractory can be further prolonged by making it appropriate.
That is, the present invention is a waste treatment apparatus as described below.

(1) A gasification and melting furnace that partially oxidizes, gasifies and melts waste, and an oxygen-containing gas supply port that is connected to the upper part of the gasification and melting furnace. In a waste treatment apparatus having a cylindrical gas reforming furnace, a gas duct for discharging gas from the gas reforming furnace is provided on the top peripheral wall of the gas reforming furnace, and in a horizontal section of the gas reforming furnace A waste treatment apparatus characterized in that the direction of the gas duct satisfies any of the following conditions (A) and (B), and forms a swirling flow in the gas reforming furnace.
(A) being tangential,
(B) A direction deflected by a predetermined angle with respect to the direction from the center of the gas reforming furnace toward the position of the top peripheral wall where the gas duct is provided. (2) The tip position of the oxygen-containing gas supply port is the gas reforming furnace. The waste treatment apparatus according to (1), characterized in that the distance from the inner wall to the center is a distance of 10% to 30% of the radius of the gas reforming furnace.
(3) The oxygen-containing gas supply port is provided in a direction deflected by an angle of not less than 1 degree and not more than 7 degrees with respect to the direction toward the center of the gas reforming furnace from the position of the peripheral wall of the furnace where the oxygen-containing gas supply port is provided. (2) The waste treatment apparatus according to (2).

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to lengthen the useful life of the furnace wall of a gas reforming furnace in the waste processing apparatus and waste processing method which partially oxidize and gasify and melt waste.

It is a sectional side view which shows an example of the waste disposal facility of this invention. It is a horizontal sectional view which shows the installation state of the gas duct of the gas reforming furnace of this invention. It is a horizontal sectional view which shows the installation state of the oxygen containing gas supply port of the gas reforming furnace of this invention. It is a horizontal sectional view which shows the installation state of the oxygen containing gas supply port of the gas reforming furnace of this invention. It is a sectional side view which shows the conventional waste disposal equipment.

Hereinafter, the present invention will be described in more detail with reference to FIGS.
FIG. 1 is a sectional side view showing an example of the waste treatment facility of the present invention.
In FIG. 1, 40 is a gas duct for discharging the reformed gas from the gas reforming furnace 5a, 41 is an outlet for the reformed gas, 42 is a swirling flow, and 44 is an oxygen-containing gas in the lower part of the gas reforming furnace 5a. The oxygen-containing gas supply pipe 44a to be supplied indicates the tip of the oxygen-containing gas supply port, and the other symbols indicate the same contents as in FIG.

The gas duct 40 is connected to a reformed gas discharge port 41 provided on the top peripheral wall of the cylindrical gas reforming furnace 5a, and the direction of the gas duct in the horizontal cross section of the gas reforming furnace is shown in FIGS. It is provided in the direction as shown.
In the case shown in FIG. 2A, the connection direction of the gas duct is provided so as to be tangential to the gas reforming furnace.
In the case shown in FIG. 2B, the connecting direction of the gas duct is provided so as to be deflected by a predetermined angle with respect to the direction from the center of the gas reforming furnace toward the reformed gas discharge port 41. .
Here, the center of the gas reforming furnace means the center of a circular furnace cross section. Further, the predetermined angle for deflecting the direction is preferably 10 degrees or more and less than 90 degrees. If the deflection angle is smaller than 10 degrees, the direction in which the gas is discharged from the gas reforming furnace is almost the same as the radial direction from the center of the gas reforming furnace, and it is difficult to form a swirl flow. If the angle is 90 degrees, the gas duct cannot be connected to the top peripheral wall of the gas reforming furnace.
Since the gas that has been reformed in the gas reforming furnace is set in the direction in which the gas is extracted from the reformed gas discharge port 41 as described above, a swirl flow 42 is formed in the gas reforming furnace.

The pyrolysis gas charged into the high-temperature reactor from the tunnel-type heating furnace and the gas generated from the waste deposition layer of the gasification melting furnace are produced by the oxygen-containing gas from the oxygen-containing gas supply port in the gas reforming furnace. The gas is supplied and partly combusted and the temperature rises. The gas is kept at a temperature of 1200 ° C. or higher for 2 seconds or longer, and tar is cracked. Carbon monoxide and hydrogen, water vapor and carbon dioxide are removed. The gas is mainly reformed.
The gas in the gas reforming furnace is partially combusted and the temperature rises, and a swirl flow is formed as described above. Therefore, as shown in FIG. 1, from the lower part to the upper part of the gas reforming furnace. Ascending while turning in a spiral trajectory.
Here, gas with a relatively low temperature has a high density, and a gas with a relatively high temperature has a low density. Therefore, the gas in the revolving gas reforming furnace is affected by centrifugal force, and the high-density temperature is compared. A relatively low gas flows to the furnace wall side, and a relatively low temperature gas flows to the furnace center side. Therefore, the surface of the refractory on the furnace wall can be brought into contact with a relatively low temperature gas, so that the refractory does not come into contact with excessively high temperature gas and prolongs the service life of the refractory. Can do.

In addition, the present invention is also characterized in how oxygen gas is supplied through the oxygen gas supply port.
FIG. 4 (a) shows the combustion state in the vicinity of the oxygen-containing gas supply port in the conventional method. At the tip of the oxygen-containing gas supply port provided at the lower part of the gas reforming furnace, The introduced pyrolysis gas burns with the oxygen-containing gas to form a high-temperature fire point, and heats the pyrolysis gas to a high temperature. In the prior art, the tip of the oxygen-containing gas supply port is open to the furnace wall of the gas reforming furnace, and the high-temperature fire point 45 is formed in the vicinity of the furnace wall, so that the furnace wall is easily consumed.

In contrast, in the present invention, the oxygen-containing gas supply pipe for supplying the oxygen-containing gas to the gas reforming furnace is arranged as shown in FIG.
That is, as shown in FIG. 3, the position of the front end portion 44a of the oxygen-containing gas supply port is such that the distance (L) between the front end portion 44a and the gas reforming furnace inner wall is 10% or more of the gas reforming furnace radius (R). Provide a distance of 30% or less on the center side. By doing in this way, the high temperature hot spot at the front end of the oxygen-containing gas supply port can be formed on the center side in the furnace, and the high temperature hot spot exists at a position away from the furnace wall. An excessively high temperature can be prevented, and the useful life of the refractory can be extended.

  When the oxygen-containing gas supply pipe is arranged as shown in FIG. 3, as shown in FIG. 4 (b), a high-temperature fire is placed near the oxygen-containing gas supply port at the bottom of the gas reforming furnace in the center of the furnace. By forming the point 45, a relatively low temperature pyrolysis gas rising from the gasification melting furnace flows in the vicinity of the furnace wall, and the furnace wall refractory becomes excessively hot at this point as well. And the service life of the refractory can be extended.

When the position of the front end portion 44a of the oxygen-containing gas supply port is provided such that the distance (L) between the front end portion 44a and the inner wall of the gas reforming furnace is shorter than 10% of the gas reforming furnace radius (R), Since the high-temperature fire point formed at the front end of the contained gas supply port is close to the inner wall of the gasification reforming furnace, the refractory is excessively heated to shorten the service life.
Further, when the position of the front end portion 44a of the oxygen-containing gas supply port is provided such that the distance (L) between the front end portion 44a and the inner wall of the gas reforming furnace is longer than 30% of the gas reforming furnace radius (R). Since the high-temperature fire point at the tip of the oxygen-containing gas supply port is formed too close to the center of the furnace, the high-temperature region is reduced, and the efficiency of heating the gas in the furnace is reduced, which is not preferable.

  Furthermore, as another aspect of the present invention, as shown in FIG. 4C, the position of the tip 44a of the oxygen-containing gas supply port at the lower part of the gas reforming furnace is changed from the inner wall of the gas reforming furnace to the gas reforming furnace. The oxygen-containing gas supply port is provided so as to be on the center side by a distance of 10% to 30% of the radius, and the oxygen-containing gas supply port is directed from the position of the furnace peripheral wall where the oxygen-containing gas supply port is provided toward the center of the gas reformer. On the other hand, it is provided in a direction deflected by an angle of 1 to 7 degrees. As a result, a swirling flow can be formed even in the lower part of the gas reforming furnace, and the gas having a relatively low density and high temperature is affected by the centrifugal force, and the gas having a relatively low density and low temperature is placed on the furnace wall side. It will flow to the furnace center side. Therefore, since the gas having a relatively low temperature can be in contact with the refractory surface of the furnace wall, the useful life of the refractory can be extended.

  If the oxygen-containing gas supply port at the lower part of the gas reforming furnace is provided in a direction deflected at an angle greater than 7 degrees with respect to the direction toward the center of the gas reforming furnace from the position of the peripheral wall of the furnace where the oxygen-containing gas supply port is provided Since the high-temperature fire point formed at the front end of the oxygen-containing gas supply port is in contact with or close to the inner wall of the gasification reforming furnace, the refractory is excessively heated to shorten the service life. Even if the oxygen-containing gas supply port is provided in a direction deflected at an angle smaller than 1 degree with respect to the direction toward the center of the gas reforming furnace from the position of the peripheral wall of the furnace where the oxygen-containing gas supply port is provided, Since it is difficult to form a swirling flow in the lower part of the furnace, it is not preferable.

The waste treatment process by the waste treatment apparatus of the present invention will be described below. In the waste treatment facility shown in FIG. 1, the compression-molded waste (compression molded product 10i) was dried, pyrolyzed, and dried. The compression molded product 11n is charged into the high temperature reactor 5 through the waste inlet 4f provided on the side wall of the high temperature reactor 5, and the waste deposit of the waste 11 is placed in the gasification melting furnace 5b of the high temperature reactor 5. Layer 12 is formed.

  The oxygen-containing gas is supplied to the lower part of the waste accumulation layer 12 from the oxygen-containing gas lower supply port 15a provided at the lower part of the gasification melting furnace 5b, and the thermal decomposition of the waste 11 dropped from the upper part of the waste accumulation layer 12 A combustible material such as carbon is combusted, and the waste energy 11 is further partially oxidized and gasified by the thermal energy, and incombustible components (metal, ash, etc.) in the waste material 11 are melted to generate a melt 14. In the melt heating / insulating furnace 16 connected to the lower side wall of the high-temperature reactor 5, the melt 14 is heated with a high-temperature combustion gas supplied from a combustion gas supply device 17 such as a burner, and a trace amount contained in the melt. The carbon 14 and the like are gasified and removed, and the melt 14 is discharged as molten slag and molten metal from the melt outlet 14H.

The pyrolysis gas charged into the high-temperature reactor 5 from the tunnel heating furnace 4 and the gas generated from the waste deposition layer 12 of the gasification melting furnace 5b are the upper part of the high-temperature reactor 5 (gas reforming furnace 5a). ) Is partly combusted and is retained for 2 seconds or more in the region where the gas temperature is 1200 ° C. or higher, and is reformed into a gas mainly containing carbon monoxide, hydrogen, water vapor, and carbon dioxide. It becomes a swirl flow 42 and is discharged to the gas duct 40 from the generated gas discharge port 41 without excessively heating the furnace wall of the reforming furnace. After cooling in the quenching device 30 and purification in the gas purification device 31, it is used for fuel. It is recovered as purified gas 33.
In this way, the waste 11 is treated by partially oxidizing, gasifying and melting the waste 11 while suppressing the consumption of the furnace wall of the gas reforming furnace.

  According to the present invention, damage to the furnace wall refractory can be prevented, and the gasification reforming furnace and the like can be stably operated over a long period of time, so that it can be suitably used in a waste gasifier.

DESCRIPTION OF SYMBOLS 1 Compression apparatus 2 Piston for compression 3 Compression support board 4 Tunnel-type heating furnace 4a Drying area | region 4b of a compression molding product Thermal decomposition area | region 4e of a compression molding object Inlet of a tunnel type heating furnace (inlet of a compression molding object)
4f Tunnel heating furnace outlet (extruded dried product outlet)
DESCRIPTION OF SYMBOLS 5 High temperature reaction furnace 5a Gasification melting furnace 5b Gas reforming furnace 6a, 6b Flow pipe 10a, 10i for heating High temperature gas Compression molding 11 Waste 11i, 11n Dried compressed product 12 Waste deposition layer 14 Melt 14H Melt discharge port 15 Gasification melting furnace oxygen-containing gas supply pipe 15a Gasification melting furnace oxygen-containing gas supply port 16 Melt heating / warming furnace 16e Melt heating / warming furnace inlet (melt inlet)
17 Combustion gas supply device (burner)
17a Combustion gas supply port 18 Reformed gas discharge port 19 Gas duct 20 Waste input port 21 Waste input port cover 30 High-temperature reactor reformed gas quenching device 31 Gas purification device 32 Reformed gas discharge port 33 Purified gas 40 Gas duct 41 Reformed gas outlet 42 Swivel flow 44 Gas reforming furnace oxygen-containing gas supply pipe 44a Gas reforming furnace oxygen-containing gas supply port 45 High-temperature fire point f ₁ Direction of movement of compression molding f _{2 of} dried compression molding Movement direction f ₃ Flow direction of pyrolysis gas generated in the tunnel type heating furnace f ₄ Direction of blowing oxygen-containing gas into the lower part of the gasification melting furnace f ₅ Direction of movement of compression piston f ₆ Direction of movement of compression support plate f ₇ Rotation direction of lid of waste input port

Claims (3)

A gasification melting furnace that partially oxidizes, gasifies and melts waste, and a cylinder that is connected to the upper part of the gasification melting furnace and has an oxygen-containing gas supply port to reform the gas generated in the gasification melting furnace In a waste treatment apparatus having a gas reforming furnace having a shape, a gas duct for discharging gas from the gas reforming furnace is provided on the top peripheral wall of the gas reforming furnace, and the direction of the gas duct in the horizontal section of the gas reforming furnace Satisfies the following conditions (A) and (B), and forms a swirl flow in the gas reforming furnace.
(A) being tangential,
(B) The direction is a predetermined angle with respect to the direction from the center of the gas reforming furnace toward the position of the top peripheral wall where the gas duct is provided.   2. The waste treatment apparatus according to claim 1, wherein the front end position of the oxygen-containing gas supply port is a center side from the inner wall of the gas reforming furnace by a distance of 10% to 30% of the radius of the gas reforming furnace. . The oxygen-containing gas supply port is provided in a direction deflected by an angle of not less than 1 degree and not more than 7 degrees with respect to the direction from the position of the peripheral wall of the furnace where the oxygen-containing gas supply port is provided toward the center of the gas reforming furnace. The waste treatment apparatus according to claim 2, wherein

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