JP3075333B2 - Melt slag outlet structure of incineration ash melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of discharging molten slag in a municipal solid waste incineration ash melting furnace without clogging at a slag outlet, accurately controlling the amount of slag, and positioning the molten slag at a predetermined position. The present invention relates to a slag outlet of molten slag of an incineration ash melting furnace for leading to a slag outlet.

[0002]

2. Description of the Related Art There is known an electric furnace type melting furnace for melting municipal waste incineration ash. FIG. 5 is a sectional view showing an example of a conventional electric furnace type incineration ash melting furnace.

In a conventional electric furnace type incineration ash melting furnace (hereinafter referred to as "ash melting furnace") 1 shown in FIG.
An electrode 3 is provided in the furnace body 2 so as to be movable up and down, the electrode 3 is inserted into the incineration ash layer 4 charged into the furnace body 2, and the incineration ash is melted by heating of the arc to be liquefied into molten slag and molten metal. A molten slag layer 5 and a molten metal layer 6 are formed. Thereafter, while maintaining the tip of the electrode 3 at a certain distance from the surface of the molten slag layer 5, the incinerated ash is melted and melted by the arc heat generated between the electrode 3 and the molten metal layer 6. Liquefies into slag and molten metal. A slag port 13 is provided at a predetermined position on the furnace wall of the furnace body 2, and molten slag and molten metal are discharged by overflowing from the slag port 13 (hereinafter, referred to as “prior art”).
In the prior art, since the incinerated ash is melted by the arc heat generated between the electrode 3 and the molten metal layer 6, the molten slag layer needs to be as thin as possible. For this reason, overflow from the slag port 13 is performed at any time.

The basicity of molten slag of municipal solid waste incineration ash is
Generally, it is around 0.4, and even when the melting temperature is in a high temperature range, the viscosity is high, and it is difficult to flow when slag is discharged outside the furnace. Therefore, in the prior art, the viscosity is lowered to facilitate the flow by means such as heating the slag portion with an auxiliary heat source or adjusting the basicity by CaO content or the like. In addition, since molten slag and molten metal are mixed and discharged, if a metal water-cooled part is used in the slag port, there is a danger of water leakage accidents and water vapor explosion due to melting damage by the molten metal. . Therefore, although the slag port is designed with a refractory structure, the life of the slag port is short because there is no refractory with excellent slag resistance.

[0005]

However, when the above measures are not taken, the smelt outlet is closed and the operation of the ash melting furnace becomes impossible. As described above, in the conventional ash melting furnace, an auxiliary heat source is required, and it is necessary to additionally input energy by melting the basicity adjusting agent together with the incinerated ash. Further, the basicity adjuster is expensive and economically disadvantageous.

Accordingly, an object of the present invention is to provide a municipal solid waste incineration ash melting furnace capable of discharging molten slag without blocking a discharging port without using auxiliary heating or a basicity adjusting agent. Another object of the present invention is to provide a molten slag slag outlet structure including a slag slag discharging mechanism capable of improving the durability of the slag outlet and adjusting the amount of slag.

[0007]

According to the first aspect of the present invention,
A molten slag discharge port is provided on a furnace wall at a middle portion in the height direction of the incineration ash melting furnace, a molten metal discharge port is provided on a furnace wall near the bottom of the melting furnace, and an incineration ash layer charged into the melting furnace is provided. An electrode penetrates and is inserted into the molten slag of the incinerated ash and melts the incinerated ash by electric resistance heating to form a molten slag layer and a molten metal layer.During melting, the tip of the electrode is placed in the molten slag layer. The molten slag is melted from the slag port by the pressure of the molten slag while the incinerated ash is melted and the molten slag layer is maintained at a height above the slag port by a predetermined distance while being melted. The molten metal is a slag outlet structure of a molten slag of an incineration ash melting furnace discharged from the discharge port, a metal chip having an opening of a predetermined area, and a water cooling structure for cooling the chip. Metal base with A movable gate made of a metal having a water cooling structure for changing the area of the opening, and the chip is fitted in the base so as to be detachable, and the movable gate By changing the opening area of the chip,
It is characterized by adjusting the discharge amount of the molten slag.

According to a second aspect of the present invention, in the first aspect of the present invention, the area and shape of the opening of the chip is a circle having an inner diameter of 10 mmφ or more, or another area having the same area or more as the circular opening. It is characterized by having a shape.

The invention described in claim 3 is the first or second invention.
In the invention described above, a metal water-cooling gutter having a water-cooling structure for guiding the molten slag discharged to the outside of the slag port to a predetermined position is provided.

[0010]

The present inventors have already developed an electric melting furnace utilizing electric resistance heat as a melting furnace for municipal waste incineration ash. In the present invention, an electric melting furnace utilizing the electric resistance heat is used. That is, the electrode penetrates the incineration ash layer charged into the furnace and is inserted into the molten slag in which the incineration ash is melted, where it generates Joule heat to melt the incineration ash and liquefy it into molten slag and molten metal. Thereby, the molten slag and the molten metal are separated by a specific gravity in the melting furnace, so that a molten slag layer and a molten metal layer are formed. The molten slag layer accumulated in the furnace has a predetermined thickness in order to utilize electric resistance heat. A slag port is provided on the furnace wall in the middle of the furnace in the height direction, and a certain level difference is secured between the molten metal surface of the molten slag layer and the slag port. The molten slag is extruded by the pressure of the slag (head pressure) and discharged from the slag port. Even if the molten slag has a basicity of 0.5 or less and has a high viscosity, the slag can be continuously discharged without closing the slag opening. Control the amount of molten slag discharged from the slag port or the amount of incinerated ash to control the level of the molten slag so that the height difference between the molten slag surface and the slag outlet always exceeds the specified value. Always keep it above the specified value. A metal outlet is provided on the furnace wall near the bottom of the melting furnace, and the molten metal is discharged from the metal outlet. In the present melting furnace, since the molten slag and the molten metal are separated by a specific gravity in the melting furnace, no metal component is mixed in the molten slag. Even when used, the durability of the metal part can be maintained. In addition, since the opening and closing mechanism has a double structure with the base and the chip fitted into it, only this chip that is exposed to the outside air and comes into contact with the molten slag that directly passes through the portion where oxidation wear occurs is replaced. This facilitates repair work and reduces repair costs. The reason why the area and shape of the opening of the tip of the slag port is defined as a circle having an inner diameter of 10 mmφ or more is that if it is less than that, there is a high possibility that the slag will not flow out. The same applies to the case where the opening has another shape having the same area or more than the circular opening.

[0011]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of an electric furnace type municipal waste incineration ash melting furnace according to an embodiment of the present invention, FIG. 2 is a sectional view showing one embodiment of a molten slag discharge port of the present invention, and FIG. It is.

As shown in FIG. 1, an electrode 3 is vertically movable within a furnace main body 2 of an electric furnace type municipal waste incineration ash melting furnace (ash melting furnace) 1. A slag port 7 is provided in a furnace wall at an intermediate portion in the height direction of the furnace main body 2, and a metal discharge port 12 is provided in a furnace wall near the furnace bottom. The electrode 3 penetrates through the incineration ash layer 4 and is inserted into the molten slag in which the incineration ash is melted, where it generates Joule heat to melt the incineration ash and liquefy it into molten slag and molten metal. And a molten metal layer is formed. Since the melting furnace used in the present invention utilizes electric resistance heat, the molten slag layer accumulated in the furnace has a predetermined thickness. The position of the molten metal level is adjusted so that a predetermined height difference can be secured between the slag outlet 7 and the molten metal level of the molten slag layer 5. The molten slag is discharged from the slag port 7 by the head pressure.

As shown in FIGS. 1 to 3, the molten slag discharge port 7 has an opening / closing mechanism 8. The opening / closing mechanism 8 includes an annular base (slag base) 8b having an opening 77 provided at an outlet of the slag port 7 of the furnace body 2, a tip 8c having an opening 88 fitted into the opening 77, and a base. It comprises a gate 8a which is provided on the outside of the chip 8b so as to close the opening 88 of the chip 8c and which can be slid up and down. Base 8b
The gate 8a and the gate 8a are both made of metal and have a water-cooled structure. The tip 8c is cooled by heat conduction from the base 8b. The amount of molten slag discharged is controlled by adjusting the opening degree of the opening / closing mechanism 8. In this embodiment, the opening 88 has an inner diameter of φ1.
0 mm or more (indicated by x in FIG. 2). Reference numeral 10 denotes an inlet / outlet of cooling water 11 for water-cooling the gate 8a and the base 8b. The amount of slag is controlled by the opening / closing mechanism 8 so as to balance the amount of molten slag in incineration ash, and the position of the molten metal surface of the molten slag layer 5 is maintained within a specified range. A predetermined height difference is maintained with the mouth 7 to constantly maintain the head pressure.

FIG. 4 is a sectional view showing another embodiment of the present invention having a water cooling gutter. The water cooling gutter 9 is provided outside the slag port 7. The water cooling gutter 9 has a water cooling structure and is made of metal. The discharged molten slag can be guided to a predetermined position by a water cooling gutter 9. The angle of the water cooling gutter 9 may be a predetermined angle that is steep enough to allow molten slag to flow out. For example, it is 35 ° or more.

Further, as a method of maintaining the position of the molten metal surface of the molten slag layer 5 within a specified range, a method of controlling the amount of incinerated ash introduced into the furnace may be used.

As shown in the prior art, in the conventional ash melting furnace, the molten slag was discharged out of the furnace by falling under its own weight together with the molten metal by an overflow method. In the embodiment of the present invention, the molten metal level of the molten slag is adjusted so that the distance between the slag port 7 and the molten metal level of the molten slag is 200 mm or more (the distance A in FIG. 1). The molten slag is extruded from the slag port 7 using the head pressure. Thus, even if the molten slag has a basicity of 0.5 or less and has a high viscosity, the slag can be continuously discharged without closing the slag opening 7. Therefore, a basicity adjuster and auxiliary heating means are not required. Further, since it is possible to use a metal water-cooled part for the slag port, it is possible to provide a slag slag discharging mechanism capable of improving the durability of the slag port and adjusting the amount of slag. it can.

[0017]

As described above, the present invention has the following industrially useful effects. Even with a high viscosity molten slag with a basicity of 0.5 or less,
The slag can be discharged without closing the slag port without using auxiliary means such as heating of the slag portion and use of a basicity adjusting agent. Since there is no need to heat the slag portion and use a basicity adjuster, it is economically advantageous without deteriorating the power consumption unit. Since the metal is separated in the melting furnace in the specific gravity, the metal component does not mix into the molten slag, which allows the use of metal water-cooled structural parts in the slag port, greatly improving the durability of the slag port. In addition, the amount of slag can be accurately adjusted. The opening / closing mechanism has a dual structure of base and chip, and a slag outlet is constructed with a base that is directly cooled with water and a chip that is indirectly cooled with water in contact with a metal touch. The structure is such that only the chip that comes into contact is replaced, so that repair work is facilitated and repair cost is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electric furnace type municipal waste incineration ash melting furnace according to an embodiment of the present invention.

FIG. 2 is a sectional view showing one embodiment of a molten slag slag outlet of the present invention.

FIG. 3 is a front view showing one embodiment of a molten slag discharging port of the present invention.

FIG. 4 is a sectional view showing another embodiment of the molten slag slag outlet of the present invention.

FIG. 5 is a sectional view showing an example of a conventional electric furnace type incineration ash melting furnace.

[Explanation of symbols]

 Reference Signs List 1 electric furnace type municipal waste incineration ash melting furnace 2 furnace body 3 electrode 4 incineration ash layer 5 molten slag layer or molten slag 6 molten metal layer 7 molten slag discharge port 77 opening (inner diameter of base) 8 opening / closing mechanism 88 opening 8a Gate 8b Base 8c Chip 9 Water cooling gutter 10 Cooling water inlet / outlet 11 Cooling water 12 Metal outlet 13 Slag outlet

Continuation of the front page (72) Inventor Yasuo Sekizawa 2743, Suzawa, Oaza-machi, Aomi-cho, Nishikubiki-gun, Niigata (72) Inventor Tsuneo Yamashita 1-180, Kamikari, Itoigawa-shi, Niigata U) Japanese Utility Model Showa 58-21735 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23J 1/08 F27B 3/19 F27D 3/14

Claims (3)

(57) [Claims] 1. A molten slag discharge port is provided on a furnace wall at an intermediate portion in a height direction of an incineration ash melting furnace, and a molten metal discharge port is provided on a furnace wall near the bottom of the melting furnace. The incinerated ash layer is penetrated by the electrode and inserted into the molten slag of the incinerated ash, and the incinerated ash is melted by electric resistance heating to form a molten slag layer and a molten metal layer. While being positioned in the molten slag layer and melting the incinerated ash, while maintaining the molten metal level of the molten slag layer at a height above the slag port by a predetermined distance, the pressure of the molten slag causes the slag removal. The molten slag is discharged from a port, and the molten metal is a slag discharge structure of a molten slag of an incineration ash melting furnace discharged from the discharge port, and a metal chip having an opening of a predetermined area, and cooling the chip. Have a water cooling structure It has an opening and closing mechanism consisting of a metal base and a metal movable gate having a water cooling structure for changing the area of the opening, and the chip is fitted to the base so as to be removable. The molten slag discharge port structure of the incineration ash melting furnace, wherein the movable gate is moved to change the opening area of the chip to adjust the amount of molten slag discharged. 2. An area and a shape of an opening of the chip are as follows.
The slag port structure according to claim 1, wherein the slag opening structure is a circle having an inner diameter of 10 mmφ or more, or another shape having the same area or more as the circular opening. 3. The slag according to claim 1, wherein a metal water-cooling gutter having a water-cooling structure for guiding the molten slag discharged to a predetermined position is provided outside the slag port. Mouth structure.