JPH11118122A - Electrical ash melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively melt ash by eliminating uneven temperature distribution by stirring molten slag. SOLUTION: A plasma ash melting furnace is adapted such that an ash introduction hole 8 is formed in one side of a furnace body 1 where base metal is contained on the bottom, and a slag drawing hole is formed in the other side, and further ash melting plasma electrodes 3A, 3B are suspended from the top wall. In the furnace, there is provided electromagnetic induction metal stirrer including a solenoid stirring part provided on a side wall 1c and the bottom wall of the furnace body 1, which stirring part serves to pass a magnetic flux through the interior of the base metal to fluidize the base metal. Molten slag is mixed and stirred by use of the fluidization of the base metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric ash melting furnace in which a base metal as a conductor is accommodated in a furnace bottom and ash is heated and melted by utilizing plasma, arc or Joule heat.

[0002]

2. Description of the Related Art Among electric ash melting furnaces for reducing the volume by heating and melting ash incinerated municipal solid waste by utilizing plasma, arc or Joule heat, for example, a plasma ash melting furnace is a furnace. Base metal is stored at the bottom of the main body,
An ash inlet is formed in the front wall, a slag outlet is formed in the rear wall, and a negative electrode and a positive electrode hang down from the top wall. Here, the ash introduced from the ash inlet is heated and melted at 1400 ° C. to 1500 ° C. by a plasma arc formed between both electrodes and the base metal, and is also flowed by the plasma arc to remove slag. It is discharged from the exit. The thickness of the base metal at this time is 200
~ 300mm, thickness of molten slag is 100 ~ 150mm
It is.

[0003]

However, the flow of the molten slag is caused by the heat of the plasma arc, and the convection of the molten slag is stopped under the condition that the temperature in the furnace body becomes uniform. For this reason, there has been a problem that the nonuniformity of the temperature of the molten slag is not eliminated, and the melting speed of the ash is low and the efficiency is low.

An object of the present invention is to provide an electric ash melting furnace which solves the above problems and promotes the flow of molten slag to efficiently melt ash. Aim.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, an ash inlet is formed at one side of a furnace main body in which a base metal is accommodated at a bottom portion. In an electric ash melting furnace in which a slag discharge port is formed on the other side and an electrode for supplying electric energy for ash melting is hung on the top wall, a magnetic flux is passed through the base metal through the furnace body to the base of the furnace. An electromagnetic induction type slag stirring device for fluidizing metal is provided.

According to the above construction, the base metal is fluidized by the electromagnetic force by utilizing the electromagnetic induction action (Lorentz force) generated by the magnetic flux passing through the base metal by the slag stirring device, and thereby the molten slag is melted. By mixing and stirring, the temperature distribution can be made uniform and the ash can be efficiently melted.

According to a second aspect of the present invention, the electrode is constituted by a plurality of plasma electrodes including a negative electrode and a positive electrode which form a plasma arc between the base metal and the slag stirring device. And a magnetic field generating part for flowing the base metal from the anode to the positive electrode side.

According to the above configuration, the base metal is caused to flow from the negative electrode side where the plasma arc is stable to the positive electrode side where the plasma arc is unstable, and the sufficiently molten molten slag is moved below the positive electrode. The plasma arc of the positive electrode can be stabilized, and the operation of the ash melting furnace can be performed stably.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of a plasma type ash melting furnace according to the present invention will be described with reference to FIGS.

In this plasma type ash melting furnace, a pair of plasma torches, that is, a positive electrode 3A and a negative electrode 3B are provided on a top wall 1a of a furnace main body 1 in which a melting chamber 2 is formed so as to be vertically movable. 4, a DC voltage is applied to both electrodes 3A and 3B, and gas supply holes 3a and 3b formed in both electrodes 3A and 3B and a gas supply hole (not shown) formed in the furnace body 1 are used to melt the chamber. When the plasma working gas is supplied into the inside 2, a plasma arc is formed between the electrodes 3 </ b> A and 3 </ b> B and the base metal 5 housed at the bottom of the melting chamber 2, and the refuse incinerator is made using this heat. The ash A discharged from such as is heated and melted.

An ash inlet 8 for supplying ash A from an ash supply hopper 6 via an ash pusher 7 is formed on the positive electrode 3A side of the furnace body 1. A slag outlet 9 for discharging molten slag MS generated by heating and melting the ash A by the plasma arc is formed on the cathode 3B side of the furnace body 1, and the molten slag MS is discharged from the slag outlet 9 through the slag outlet 9. The granulated slag WS is formed by being charged into a granulated pit 11 arranged below the slag cooling chamber 10.

In the furnace body 1, the base metal 5 is fluidized by utilizing the electromagnetic induction effect of the first magnetic field generating section 21 and the second magnetic field generating section 22, and thereby the molten slag MS is agitated and ash A and An electromagnetic induction type slag stirring device 20 capable of effectively heating and melting the molten slag MS is provided.

That is, the bottom wall 1b of the furnace body 1 has a built-in first magnetic field forming portion 21 for forming a fixed magnetic flux in the base metal 5 over the positions corresponding to the electrodes 3A and 3B. The magnetic flux formed at the portion 21 and the current flowing through the base metal 5 between the electrodes 3A and 3B during the formation of the plasma arc make use of the electromagnetic induction (Lorentz force) generated from the negative electrode 3B to the positive electrode. An electromagnetic force is generated on the 3A side to cause the base metal 5 to flow in the direction of the arrow E.

The left and right side walls 1c, 1c of the furnace body have
Second magnetic field forming portions 22 and 22 for forming a moving magnetic flux are provided in the base metal 5, respectively, and the Lorentz force generated by the moving magnetic flux is used to move the ash supply port 8 to the slag outlet 9 side. An electromagnetic force is generated to cause the base metal 5 to flow in the direction of arrow F.

The first and second magnetic field generators 21 and 22 are provided with an iron core and a coil, respectively, and the first magnetic field generator 21 is provided with a base metal 5 by a current supplied from the electromagnetic induction controller 23. Is formed, and a moving magnetic field is formed in the second magnetic field generating unit 22. And
On the surfaces of the first and second magnetic field generating parts 21 and 22, a refractory material which does not hinder the passage of the magnetic flux is provided. The bottom wall 1
When the magnetic field b and the side wall 1c do not hinder the passage of the magnetic flux or the attenuation thereof is small, the first and second magnetic field generating parts 21 and 22 can be arranged on the outer surfaces of the bottom wall 1b and the side wall 1c. .

In the above configuration, the gas supply holes 3a, 3b
A plasma working gas such as a nitrogen gas is supplied to the melting chamber 2 and the like, a voltage is applied to both electrodes 3A and 3B, and a plasma arc is formed between the electrodes 3A and 3B and the base metal 5 to form a base. The metal 5 is preheated and melted. When the temperature reaches a predetermined temperature, the ash A in the ash supply hopper 6 is put on the base metal 5 through the ash inlet 8 by the ash pusher 7 and is heated and melted. When the molten slag S reaches a certain level, the molten slag S is discharged from the slag outlet 9 to the granulation pit 11 of the slag cooling chamber 10 and is water-cooled to produce granulated slag WS.

At this time, the base metal 5 is caused to flow in the direction of arrow E by the magnetic flux passing through the base metal 5 by the first magnetic field forming part 21 and the current flowing between the electrodes 3A and 3B. Thus, the high-temperature molten slag MS sufficiently melted from the negative electrode 3B side where the plasma arc is stable flows to the positive electrode 3A side where the plasma arc is unstable, so that the molten slag M below the positive electrode 3A is melted.
The molten state of S can be homogenized to stabilize the plasma arc of the positive electrode 3A, and the ash melting furnace can be operated stably.

The base metal 5 is caused to flow in the direction indicated by the arrow F by passing the moving magnetic flux generated by the second magnetic field generators 22 and 22 through the base metal 5. A circulating flow in the E and F directions is formed, and the molten slag MS can be fluidized and agitated and mixed, thereby reducing the temperature difference of the molten slag MS and effectively melting the ash A in a short time. Can be.

In the above embodiment, the slag stirring device 20 is applied to a plasma type ash melting furnace, but may be an arc furnace or a resistance furnace. Further, the magnetic field generators 21 and 22 are provided on the bottom wall 1b and the side wall 1c of the furnace main body 1, respectively, but any one may be used as long as the effect of stirring the molten slag MS is sufficiently obtained. The number of electrodes at this time does not matter.

Further, in the two magnetic field generating sections 21 and 22, the base metal 5 is configured to flow in a horizontal plane. However, the magnetic field generating section is disposed at an arbitrary position on the side wall, and the base metal 5 is formed in a vertical plane. It may flow and agitate the molten slag MS.

[0021]

As described above, according to the first aspect of the present invention, the electromagnetic force (Lorentz force) generated by the magnetic flux passing through the base metal is used to generate the base metal by the electromagnetic force. Is fluidized, whereby the molten slag is mixed and stirred, whereby the temperature distribution is made uniform and the ash can be efficiently melted.

According to the second aspect of the present invention, the base metal is caused to flow from the negative electrode side where the plasma arc is stable to the positive electrode side where the plasma arc is unstable, and the molten slag that has been sufficiently melted is placed under the positive electrode. By moving to
The plasma arc of the positive electrode can be stabilized, and the ash melting furnace can be operated stably.

[Brief description of the drawings]

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

FIG. 2 is a plan sectional view of the melting furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace main body 1b Bottom wall 1c Side wall 2 Melting chamber 3A Positive electrode 3B Negative electrode 4 Power supply 5 Base metal 8 Ash inlet 9 Slag outlet 20 Slug stirrer 21 First magnetic field generator 22 Second magnetic field generator 23 Electromagnetic induction control Department

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Sato 5-28 Nishikujo, Konohana-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Kunio Sasaki 5-chome, Nishikujo, Konohana-ku, Osaka-shi, Osaka 3-28 No. within Hitachi Zosen Corporation (72) Inventor Yoshitoshi Sekiguchi 5-28-3 Nishikujo, Konohana-ku, Osaka-shi, Osaka Prefecture 3-72 Inside Hitachi Zosen Corporation (72) Inventor Yuroro Sakata, Konohana-ku, Osaka-shi, Osaka Hitachi Shipbuilding Co., Ltd. (72) Inventor Hirofumi Kosaka 5-93 Kujo 3-chome, Nishikujo, 3-chome, Konohana-ku, Osaka, Japan

Claims (2)

[Claims] An ash inlet is formed at one side of a furnace body containing a base metal at the bottom and a slag outlet is formed at the other side to supply electric energy for melting ash to a ceiling wall. An electric ash melting furnace in which the electrode to be suspended is provided with an electromagnetic induction type slag stirrer in a furnace main body for allowing magnetic flux to pass through the base metal to fluidize the base metal. Melting furnace. 2. An electrode comprising a plurality of plasma electrodes comprising a cathode and a cathode, which form a plasma arc between the base metal and the base metal. 2. The electric ash melting furnace according to claim 1, further comprising a magnetic field generator for flowing the ash.