JPH05253557A - Incineration ash melting furnace - Google Patents

Abstract

PURPOSE: To realize an incineration ash melting furnace which is applied for attaining volume-reduction, detoxication and recycling as a resource of the incineration ash, has high heat efficiency and is excellent in operability, controllability and durability. CONSTITUTION: The incineration ash melting furnace is provided with a furnace main body 1 acommodating the incineration ash and a graphite electrode 2 blowing out plasma gas 4 toward the incineration ash accommodated in the furnace main body 1. Molten slag 8 is obtained by heating and melting the incineration ash by a plasma arc system using the graphite electrode as a cathode and a positive electrode 7 at a furnace bottom part as an anode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incinerator ash melting furnace applied to ash treatment of environmental equipment products.

[0002]

2. Description of the Related Art In recent years, burner combustion method, electric arc method, plasma water-cooled torch method, etc. have been used as a method for reducing the volume and detoxifying incineration ash such as refuse incineration ash, sewage / human waste sludge incineration ash, and industrial waste incineration ash , Various schemes are being studied.

[0003]

However, the above-mentioned method has some problems from the viewpoint of operability, safety, and durability, and no technique has been completed at present.

In view of the above circumstances, the present invention is applied to reduce the volume of incineration ash, render it harmless, and recycle it, and has a high thermal efficiency, excellent operability, controllability, and durability. The purpose is to provide.

[0005]

An incinerator ash melting furnace according to the present invention which achieves the above object is a melting furnace for heating and melting incinerated ash, and a furnace main body for accommodating the incinerated ash and a housing for the furnace main body. And a carbon electrode for ejecting a plasma gas toward the incinerated ash, the carbon electrode serving as a cathode and the incinerated ash side serving as an anode for heating and melting the incinerated ash by a plasma arc method. It is characterized by Further, particularly in the above configuration, the furnace wall of the furnace body is a water-cooled refractory wall.

[0006]

In the incinerator ash melting furnace having the above-mentioned structure, the plasma method is adopted as the heating method of the incinerated ash instead of the arc method. Further, among the plasma methods, the plasma arc method, that is, the transfer method is adopted. The ash can be heated uniformly and discharged stably. Further, by adopting a carbon electrode method as the torch for ejecting the plasma gas instead of the water cooling torch method, it is possible to eliminate steam explosion due to breakage of the water cooling loop and to improve thermal efficiency.
Further, by adopting the positive polarity in which the carbon electrode serves as the negative electrode, the life of the carbon electrode can be extended.

When the furnace wall is made of a water-cooled refractory wall and a suitable cooling load is applied to the furnace wall, a solid phase slag layer is formed on the inner surface of the furnace wall. That is, the furnace wall is protected by self-coating.

[0008]

EXAMPLES The present invention will be described below based on examples.

FIG. 1 is a conceptual diagram of an incinerator ash melting furnace according to an embodiment, and FIG. 2 is an explanatory diagram showing the furnace wall structure thereof. As shown in FIG. 1, at the top of the furnace body 1, a graphite electrode 2 having a hollow portion 2a that is cylindrical and penetrates in the longitudinal direction is provided with its tip end inserted inside the furnace body 1. ing. A flow rate adjusting device 3 for supplying plasma gas to the hollow portion 2a of the graphite electrode 2 is connected to the rear end side of the graphite electrode 2 so that the plasma gas 4 is ejected from the tip of the graphite electrode 2. It has become.

An incinerator ash supply port 1a is formed at the top of the furnace body 1, and an incinerator ash supply system 5 is connected to the incinerator ash supply port 1a.

Further, a furnace outlet gas duct 1b is provided at the furnace top of the furnace body 1, and the furnace outlet gas duct 1b is provided.
A cleaning device 6 for scattered dust is installed at b.

On the other hand, a positive electrode 7 is provided on the bottom of the furnace body 1. Then, a power source (not shown) having the positive electrode 7 as a positive electrode and the graphite electrode 2 as a negative electrode is provided.

In such an incineration ash melting furnace, the gas is supplied into the furnace main body 1 through the incineration ash supply system 5, and the plasma gas 4 consisting of an inert gas such as Ar, N ₂ and He is supplied from the tip of the graphite electrode 2. And the graphite electrode 2 is used as a cathode and the positive electrode 7 is used as an anode, the plasma arc reaches the incineration ash, and the incineration ash is heated and melted to form the molten slag 8.

A molten slag discharge port 1c is formed on the side wall of the furnace body 1, and the overflowed molten slag 8 is discharged to a water granulated slag retainer 9 and retained as a water granulated slag 10. ..

As shown in FIG. 2, the furnace wall of the furnace body 1 of the present embodiment comprises an inner refractory wall 11 and an outer furnace wall steel plate 12, and the refractory wall 11 has cooling fins 13 therein. The cooling pipes 14 are installed at an appropriate pitch.

Therefore, by supplying water to the water cooling pipe 14 and applying an appropriate cooling load to the refractory wall 11, the solid phase slag layer 15 is self-coated on the inner surface of the refractory wall 11 to prolong the life of the furnace wall. Planned.

As described above, in this embodiment, the direct current plasma furnace, particularly the plasma arc system (transfer system) is adopted, and the plasma gas 4 and the molten slag are provided between the graphite electrode 2 as the negative electrode and the positive electrode 7. By forming a closed circuit via 8 (having a positive polarity on the torch side),
Satisfying the essential conditions of uniform heating and stable discharge, the life of the electrode is extended. In addition, by adopting a carbon electrode method instead of the water-cooled torch method, steam explosion due to breakage of the water-cooled loop is eliminated and high thermal efficiency is achieved.

For example, AC arc furnace, AC plasma furnace,
Compared with other electric heating furnaces such as the DC plasma water-cooled torch method, there are fundamental differences in the current density distribution in the electrode and the torch side is the negative electrode. The effect such as disappearance is obtained.

In the present embodiment, the special dust cleaning device 6 is also used for the gasification of the low melting point substance in the incineration ash and the condensation and adhesion in the furnace outlet duct 16 at the relatively low temperature part.
This is dealt with by providing a shunt to prevent blockage troubles.

Further, in the DC plasma graphite electrode system adopted in this embodiment, the amount of plasma gas used is very small, so that the exhaust gas heat loss is small and the processing equipment itself can be made compact.

Although the positive electrode 7 is provided at the bottom of the furnace in the above-mentioned embodiment, it may be provided at the top of the furnace like the graphite electrode 2.

[0022]

The incinerator ash melting furnace of the present invention has a positive polarity torch polarity in a direct current plasma arc system using a graphite electrode. Therefore, when the volume of incinerator ash is reduced, it is rendered harmless, and it is made into a resource, It is highly efficient, has excellent operability, controllability, and safety, and has the effect of reducing electrode consumption. Further, since the amount of plasma gas used is small, the amount of exhaust gas and heat loss are small. Further, by making the furnace wall a water-cooled refractory wall, the furnace wall can be self-coated and the life can be extended.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an incinerator ash melting furnace according to an embodiment.

FIG. 2 is an explanatory diagram showing a structure of a furnace wall.

[Explanation of symbols]

 1 Furnace Main Body 2 Graphite Electrode 2a Hollow Part 3 Flow Control Device 4 Plasma Gas 5 Incineration Ash Supply System 6 Dust Cleaning Device 7 Positive Electrode 8 Molten Slag 9 Granulated Slag Retaining 10 Granulated Slag 11 Refractory Wall 12 Furnace Wall Steel Plate 13 Cooling Fin 14 Water cooling pipe 15 Solid phase slag layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Satoshi Okuno 12 Nishiki-cho, Naka-ku, Yokohama-shi Kanagawa Mitsubishi Heavy Industries, Ltd.Yokohama Works (72) Inventor Shizuo Yasuda 12 Nishiki-cho, Naka-ku, Yokohama-shi Kanagawa Yokohama Co., Ltd. (72) Inventor, Yuhime Honda, 12 Nishiki-cho, Naka-ku, Yokohama, Kanagawa Mitsubishi Heavy Industries, Ltd., Yokohama Institute (72) Inventor, Charles Peter Heinley, S.N. On, Farringdon, Little Cockswell, Seabelley House (72) Inventor Christopher David Chapman, GL7 3D, Grossestershire, Rethyrad, Mount Pleasant 3

Claims (2)

[Claims] 1. A melting furnace for heating and melting incineration ash, comprising:
A furnace main body for accommodating the incinerated ash, and a carbon electrode which is provided so as to face the incinerator ash accommodated in the furnace main body and ejects a plasma gas toward the incinerator ash, the carbon electrode being the cathode and the incinerated ash An incinerator ash melting furnace, characterized in that the incinerator ash is heated and melted by a plasma arc method using the as an anode. 2. The incinerator ash melting furnace according to claim 1, wherein the furnace wall of the furnace body is a water-cooled refractory wall.