JP2002228137A - Plasma ash waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma ash waste melting furnace which ensures separation between sedimentary molten slag and molten metal, eliminates troublesome drilling processes, prevents outflow or ash, has reduced furnace diameter with the effective utilization of melting area, improves productivity and reduces installation cost. SOLUTION: In the plasma ash melting furnace 1 for heating and melting burned ash by a plasma arc, which is fed to a furnace body 2 to produce the molten slag 3 and the molten metal 4, a slag outlet 6 and a metal discharge pipe 7 are provided at the bottom of a portion of the furnace body 2, where the molten slag 3 and the molten metal 4 are collected. A slag discharge pipe 8 and a metal discharge pipe 9 are connected to the slag outlet 6 and the metal discharge pipe 7, respectively, and a high frequency induction heating device 10 is provided around the slag discharge pipe 8 and the metal discharge pipe 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for converting wastes such as incinerated ash such as sewage sludge, municipal solid waste and industrial waste and incinerated ash discharged from an incinerator of a commercial thermal power plant or the like into a high-temperature plasma, a burner, The present invention relates to a new type of plasma ash waste melting furnace that melts with a heat source such as electricity.

[0002]

2. Description of the Related Art Conventionally, incinerated ash (powder inorganic material) such as sewage sludge, municipal solid waste, and industrial waste has been used, for example, as shown in FIG. The molten slag 5 is melted by the
2 and the molten metal 53. That is, in order to melt the incinerated ash in the furnace main body 54 using such an ash melting furnace 51, for example, the incinerated ash discharged from the refuse incinerator is transferred to the furnace main body 54 through various conveying means and supply means. The incinerated ash is charged into the plasma electrode 55.
Melts with the high-temperature plasma generated in. The molten slag 52 and the molten metal 53 generated in the furnace body 54 are discharged from an unshown slag port and slag gutter provided on the side surface of the furnace body 54 by an overflow method or the like, and are slag pitted via a conveyor. And led to metal pits for various uses.

Meanwhile, the molten slag 52 and the molten metal 53 accumulate in the furnace main body 54 during operation of the ash melting furnace 51, and the molten metal 53 is stacked below the layer of the molten slag 52 due to a difference in specific gravity. For this reason, it was difficult to discharge the molten metal 53 laminated below the molten slag 52 to the outside only by the overflow method at a position below a slag gutter (not shown). Therefore, in the conventional ash melting furnace 51,
Water cooling jacket 56 and refractory 5 constituting furnace body 54
7. A mud material (clay) 58 is applied to the molten metal 53
Is buried up to the place where the water accumulates, and after the operation is stopped, the mud material 58 is drilled with a drill 59 to communicate with the outside,
The molten metal 53 in the furnace body 54 is discharged from the communication hole and stored in the container 60, and thereafter, a new mud material 58a is buried in the hole with the mud gun 61, repaired, and the operation is resumed.

[0004]

However, in the above-mentioned conventional ash melting furnace 51, when the molten metal 53 in the furnace body 54 is discharged, the drill 59 and the mud gun 6 are used.
1 and the like, it is necessary to make a communication hole in the mud material 58 embedded therein and to embed the mud material 58a in the communication hole. Accordingly, there was a problem that productivity could not be improved. On the other hand, in the overflow method, the quality of the molten slag 52 and the molten metal 53 cannot be maintained because the molten metal 53 is leached out together with the molten slag 52 or the floating incineration ash flows out together with the molten slag 52. At the same time, the yield of incinerated ash was poor. Moreover,
The entire melting area in the furnace main body 54 could not be used, and the furnace diameter had to be increased, possibly leading to an unnecessary increase in the size of the ash melting furnace 51.

The present invention has been made in view of such circumstances, and an object of the present invention is to reliably separate molten slag from molten metal from molten metal and eliminate the need to perform a complicated drilling operation. It is an object of the present invention to provide a plasma ash waste melting furnace capable of preventing ash outflow, reducing the furnace diameter by effectively utilizing a melting area, and improving productivity and reducing equipment costs.

[0006]

According to the present invention, waste such as incineration ash introduced into a furnace body is heated by a heat source such as a plasma arc, a burner, and electricity. In the plasma ash waste melting furnace that generates molten slag and molten metal by being melted, in the furnace body, the molten slag and the molten metal are provided at the bottom of a place where the molten metal is stored, respectively. A slag discharge pipe and a metal discharge pipe are connected to the slag outlet, and a high-frequency induction heating device is provided around the slag discharge pipe and the metal discharge pipe.

Further, in the present invention, the temperature of the molten slag in the slag discharge pipe and the temperature of the molten metal in the metal discharge pipe are controlled by adjusting the output of the high-frequency induction heating device provided in a plurality of regions. Is preferred.

Further, in the present invention, it is preferable that the high-frequency induction heating device is constituted by a copper water tube coil wound around the slag discharge pipe and the metal discharge pipe. Further, in the present invention, the slag discharge pipe may be disposed to extend obliquely upward from a bottom side surface of the furnace main body, or the metal discharge pipe may extend downward from the bottom of the furnace main body, Further, it is preferable that it is formed in a bent shape having a rising pipe part lifted from the middle. In the present invention, the slag discharge pipe and the metal discharge pipe are preferably formed of a conductive refractory of ZrB2.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma ash waste melting furnace according to the present invention will be described in detail based on the illustrated embodiment. Here, FIG. 1 is a schematic diagram showing a plasma ash melting furnace according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a copper water tube coil of a high frequency induction heating device wound around a slag discharge tube and a metal discharge tube of FIG. FIG. 3 is a schematic sectional view of the copper water tube coil of FIG. Plasma ash melting furnace 1 of the present embodiment
The incineration ash (not shown) charged into the furnace main body 2 is heated and melted by a plasma arc to form a molten slag 3.
And a molten metal 4. For this reason, as shown in FIG. 1, the plasma ash melting furnace 1 has a furnace body 2 having a refractory structure formed in a bottomed cylindrical shape. In the furnace body 2, a plasma for generating a plasma arc is provided. An electrode 5 is provided hanging from the ceiling wall. Although not shown, the outer peripheral wall of the furnace main body 2 is covered with an iron shell, and the inner peripheral wall is formed of a refractory such as a refractory brick, and a water-cooling jacket for cooling the refractory is provided between them. It is arranged.

On the other hand, as shown in FIG. 1, a slag outlet 6 and a metal outlet 7 are provided at the bottom of the furnace body 2 where the molten slag 3 and the molten metal 4 are stored. Molten slag 3 and molten metal 4
Each is separated by a separate system. The positional relationship between the molten slag 3 and the molten metal 4 is such that the molten slag 3 accumulates upward and the molten metal 4 accumulates downward due to the specific gravity difference between the two, so that the slag slag port 6 is higher than the upper surface of the molten metal 4. It is arranged on the bottom side that is located above,
The metal slag port 7 is provided on the bottom surface opposite to the slag slag port 6. That is, the ash melting furnace 1 according to the present embodiment has a communication hole formed by slagging the molten slag 3 by an overflow method that overflows from a side surface of the furnace main body 2 through a slag outlet or drilling a mud material using a drill or the like. It does not have a structure in which the molten metal 4 is extracted from the slag and discharged by a mud gun method.

For this reason, one end of a slag discharge pipe 8 is connected to the slag discharge port 6, and one end of a metal discharge pipe 9 is connected to the metal discharge port 7. The other end of the pipe 9 is opened to discharge the molten slag 3 and the molten metal 4, respectively, and a storage container (not shown) is provided below the opening. The slag discharge pipe 8 is disposed to extend obliquely upward from the bottom side surface of the furnace main body 2. The metal discharge pipe 9 extends downward from the bottom surface of the furnace body 2 and is formed in a bent shape that is lifted from the middle, and the rising pipe portion 9a is formed in the middle.
And has a substantially U-shape. The upper end of the riser portion 9a is further bent outward at a right angle, and its height is set so that the molten slag 3 can be balanced with the pushing force and almost all of the molten metal 4 can be discharged. ing. The slag discharge pipe 8 and the metal discharge pipe 9 are formed of a conductive refractory using ZrB2, which is a material having high thermal conductivity, in order to quickly heat or cool the molten slag 3 and the molten metal 4 flowing therein. ing.

The slag discharge pipe 8 and the metal discharge pipe 9
Are connected to a high-frequency power supply (not shown), and are provided in a plurality of regions, respectively.
0, the molten slag 3 in the slag discharge pipe 8 is adjusted.
And the temperature of the molten metal 4 in the metal discharge pipe 9 are controlled. Therefore, as shown in FIGS. 2 and 3, the high-frequency induction heating device 10 includes a copper water tube coil (high-frequency induction coil) 11 wound around the outer periphery of the slag discharge pipe 8 and the metal discharge pipe 9. The copper water tube coil 11 is composed of a cylindrical copper pipe 13 through which water 12 flows, and an insulating film 14 covering the outer peripheral surface of the copper pipe 13. Molten slag 3 and metal discharge pipe 9
When the high-frequency current is stopped, the molten slag 3 and the molten metal 4 can be cooled.

In the plasma ash melting furnace 1 having such a structure, when incinerated ash is injected into the furnace main body 2 from an ash inlet (not shown), the injected incinerated ash is heated by a plasma arc by the plasma electrode 5 and melted. , The molten slag 3 and the molten metal 4 sinking below the molten slag 3 are stacked one above the other. During operation, when a predetermined amount of the molten slag 3 and the molten metal 4 accumulate in the furnace bottom, the molten slag 3 is subjected to temperature control via the copper water pipe coil 11 by adjusting the output of the high-frequency induction heating device 10, and the molten slag 3 is discharged. The slag is discharged while gradually rising from the port 6 through the slag discharge pipe 8, and is dropped and stored in a container (not shown). Also, the molten metal 4
In a state where the temperature is controlled through the copper water tube coil 11 by adjusting the output of the high-frequency induction heating device 10, the metal falls from the metal slag port 7 through the metal discharge pipe 9, and then passes through the riser pipe section 9a on the way. The slag is discharged while gradually rising, and is dropped and stored in a container (not shown).

In the plasma ash melting furnace 1 according to the embodiment of the present invention, separate slag outlets 6 and metal outlets 7 are provided at the bottom of the furnace where the upper molten slag 3 and the lower molten metal 4 are stored. A slag discharge pipe 8 is connected to the slag discharge port 6, a metal discharge pipe 9 is connected to the metal slag discharge port 7, and a high-frequency induction heating device 10 is connected to the outer periphery of the slag discharge pipe 8 and the metal discharge pipe 9. Because of the arrangement, the molten slag 3 and the molten metal 4 in a temperature-controlled state are separated without slagging the molten slag 3 by the overflow method or slagging the molten metal 4 by the mud gun method. It is possible to quickly and surely remove the slag from the bottom of the furnace main body 2 by the new method, while preventing the incineration ash from flowing out, and reducing the furnace diameter by effectively utilizing the melting area. To Base and improve productivity, it is possible to reduce the cost and size.

Further, in the plasma ash melting furnace 1 of the present embodiment, the high-frequency induction heating device 10 is disposed in a plurality of regions, the slag discharge pipe 8 is disposed extending obliquely upward, and the metal discharge pipe is disposed. Since the rising pipe portion 9a is provided in a substantially U-shape, the molten slag 3 and the molten metal 4 can be prevented from flowing down.

While the embodiments of the present invention have been described above,
The present invention is not limited to the embodiments described above, and various modifications and changes can be made based on the technical idea of the present invention. For example, in the above-described embodiment, the copper water tube coil 1
1 was formed into a cylindrical shape and wound around the outer periphery of the slag discharge pipe 8 and the metal discharge pipe 9, but a square tubular copper water tube coil 21 was used as shown in FIG. 4, or as shown in FIG. The copper water pipe coil 21 may be buried in the slag discharge pipe 8 and the metal discharge pipe 9. With the copper water tube coil 21 having such a shape and arrangement, the cooling effect can be promoted.

[0017]

As described above, in the plasma ash waste melting furnace according to the present invention, waste such as incineration ash charged into the furnace body is heated and melted by a heat source such as a plasma arc, a burner, and electricity. Thus, a molten slag and a molten metal are produced, and a slag outlet is provided at a bottom portion of a place where the molten slag and the molten metal are stored in the furnace main body. Since a high-frequency induction heating device is installed around the slag discharge pipe and the metal discharge pipe while connecting the discharge pipe, the molten slag and the molten metal can be reliably separated by a separate system, and the product quality is improved. Can be done. Moreover, the molten slag and molten metal are discharged by the new method without using the overflow method or a special machine to open communication holes in the mud material as in the past, so that the flow of floating ash can be reduced. In addition, the furnace diameter can be reduced by effective use of the melting area, thereby improving productivity, reducing equipment costs, and reducing the size of the furnace body.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a plasma ash melting furnace according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a copper water tube coil of the high-frequency induction heating device wound around the slag discharge tube and the metal discharge tube of FIG. 1 in the plasma ash melting furnace according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view showing the copper water tube coil of FIG. 2 in the plasma ash melting furnace according to the embodiment of the present invention.

FIG. 4 is a schematic sectional view showing a copper water tube coil according to a first modification of the embodiment of the present invention.

FIG. 5 is a schematic sectional view showing a copper water tube coil according to a second modification of the embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view illustrating a slag removal operation of a molten metal in a conventional plasma ash melting furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma ash melting furnace 2 Furnace main body 3 Molten slag 4 Molten metal 5 Plasma electrode 6 Slag discharge port 7 Metal discharge port 8 Slag discharge pipe 9 Metal discharge pipe 9a Rise pipe part 10 High frequency induction heating device 11, 21 Copper water pipe coil

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kentaro Saeki 1-8-1, Koura, Kanazawa-ku, Yokohama-shi, Kanagawa Prefecture Inside the Yokohama Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Keita Inoue 12-12 Nishikicho, Naka-ku, Yokohama-shi, Kanagawa Mitsubishi F term in Yokohama Works, Ltd. (reference) 3K061 NB02 NB03 NB07 4K045 AA04 BA10 CA08 RB02 RC11 RC16 4K051 AA00 BE00 4K055 JA01

Claims (6)

[Claims] 1. A plasma ash waste melting furnace which generates molten slag and molten metal by heating and melting a waste such as incineration ash charged into a furnace body by a heat source such as a plasma arc, a burner, and electricity. In the furnace body, in the bottom of the place where the molten slag and the molten metal accumulate, a slag outlet is provided, and a slag discharge pipe and a metal discharge pipe are connected to these slag outlets, and the slag discharge pipe and A plasma ash waste melting furnace, wherein a high frequency induction heating device is provided around the metal discharge pipe. 2. The temperature of the molten slag in the slag discharge pipe and the temperature of the molten metal in the metal discharge pipe are controlled by adjusting the output of the high-frequency induction heating device provided in a plurality of regions. The plasma ash waste melting furnace according to claim 1. 3. The high-frequency induction heating device is constituted by a copper water tube coil wound around the slag discharge tube and the metal discharge tube.
Or the plasma ash waste melting furnace according to 2. 4. The plasma ash waste melting furnace according to claim 1, wherein the slag discharge pipe extends obliquely upward from a bottom side surface of the furnace main body. . 5. The metal discharge pipe according to claim 1, wherein the metal discharge pipe extends downward from a bottom of the furnace body and has a bent shape having a riser pipe partly lifted from the middle. The plasma ash waste melting furnace according to any one of claims 1 to 3. 6. The plasma ash waste melting according to claim 1, wherein the slag discharge pipe and the metal discharge pipe are made of a conductive refractory material of ZrB2. Furnace.