JP2002098323A - Slag removing device for melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slag removing device which ensures removal of slag sticking to a slag outlet of a melting furnace, reduces running cost, and exerts excellent handleability, safety or the like. SOLUTION: A slag removing device 1 is constructed such that an object to be melted which has been supplied to a melting furnace 2 is subjected to melting treatment to obtain molten slag 6, that the molten slag 6 is allowed to overflow from a slag outlet 4 of the furnace 2, and that slag 6' sticking to the outlet 4 is removed. The device 1 consists of a blasting machine 7, which is disposed in the vicinity of the outlet 4, for blowing granular grinding material 11 to the slag 6' sticking to the outlet 4, and a grinding material feeder 8 for feeding the grinding material 11 to the blasting machine 7 with a pressurized fluid G. The grinding material 11 is jetted toward the slag 6' sticking to the outlet 4 from the blasting machine 7 together with the pressurized fluid G. Thus the slag 6' sticking to the outlet 4 is scraped off by the grinding material 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overflow type tapping electric system for melting and processing incinerated residues and fly ash discharged from an incinerator for incinerating municipal waste and industrial waste. Used in melting furnaces,
The present invention relates to a slag removing device that can reliably and safely remove the fixed slag when molten slag overflowing from a slag port of an electric melting furnace adheres to the slag port and solidifies.

[0002]

2. Description of the Related Art In recent years, in order to reduce the volume and detoxify incineration residues and fly ash (hereinafter referred to as "melted matter") discharged from incinerators for incineration of municipal solid waste and industrial waste, etc. Attention has been paid to a method of melting and solidifying a product, and the method is practically used in practice. This is because the volume of the material to be melted can be reduced to 1/2 to 1/3 by being solidified,
Prevention of elution of harmful substances such as heavy metals, reuse of molten slag,
This is because it is possible to extend the life of the final landfill site.

[0003] In the method of melting and solidifying the material to be melted, an electric melting furnace such as a plasma melting furnace, an arc melting furnace, or an electric resistance furnace is used. A method of solidifying this by water cooling or air cooling, and using a combustion type melting furnace such as a surface melting furnace, a swirling melting furnace, a coke bed furnace, etc., and melting the material to be melted by the combustion energy of the fuel, and then cooling it with water or air. The method of using electric energy of the former is also used when the power generation equipment is installed in the refuse incineration equipment, and when the power generation equipment is not installed, Many of the latter methods using combustion energy are employed.

FIG. 2 shows an example of an electric melting furnace 20 of an overflow tapping type. In FIG.
Is an electric melting furnace, 21 is an apparatus for supplying a material to be melted, 22 is a graphite main electrode, 23 is a start electrode, 24 is a furnace bottom electrode, 25
Is a slag outlet, 26 is a molten slag, 26 'is a solidified slag, 27 is an auxiliary burner, and 28 is a slag cooling water tank provided with a water-sealed slag conveyor (not shown).

[0005] The material to be melted supplied into the electric melting furnace 20 is heated to a temperature exceeding the melting point by electric energy, and becomes a high-temperature liquid molten slag 26.
The molten slag 26 sequentially overflows from the slag port 25, falls into a slag cooling water tank 28 filled with cooling water, is quenched and solidified by the cooling water to form granular granulated slag, and then is subjected to water sealing slag. It is carried out by a conveyor (not shown). This granulated slag has a high hardness and can be effectively used for concrete filler materials, roadbed materials, embankment materials, blocks and the like.

[0006] The high-temperature exhaust gas generated by the melting of the material to be melted passes through a flue and enters a secondary combustion chamber (not shown), where secondary combustion air and the like are added. The unburned gas inside is completely burned. After the combustion exhaust gas that has been completely burned is cooled by cooling air or the like,
It is released to the atmosphere via an exhaust gas treatment device (not shown).

[0007]

In the conventional electric melting furnace 20 of the overflow tapping type, the molten slag 26 is cooled immediately after the furnace operation is started or when the overflow amount of the molten slag 26 is reduced. Slag port 2
In some cases, it adhered and solidified near the exit and entrance of No. 5. As a result, the slag outlet 25 of the molten slag 26 may be blocked by the solidified slag 26 ', and in the worst case, the operation of the electric melting furnace 20 becomes impossible.

Therefore, in the conventional overflow melting type electric melting furnace 20, when the molten slag 26 is fixed to the slag port 25, the molten slag 26 is fixed to the slag port 25 by the following method. The slag 26 'was removed. An auxiliary burner 2 is provided near the discharge port 25 of the electric melting furnace 20.
The slag 26 ′ fixed to the slag port 25 is re-melted by the heat of combustion of the auxiliary burner 27. A worker manually discharges the slag port 2 of the electric melting furnace 20.
The slag 26 'fixed to 5 is removed. The slag 26 'fixed to the slag port 25 of the electric melting furnace 20 is removed by remote control using a machine.

However, in any of the above methods,
There were the following problems. That is, when the slag 26 'solidified by the combustion heat of the auxiliary burner 27 is re-melted,
The slag 26 'adhered to the slag port 25 cannot be reliably removed, and a large amount of fuel is required, so that energy saving is difficult and the fuel cost rises significantly. Of course, if the auxiliary burner 27 is used in the electric melting furnace 20 that operates in a reducing atmosphere in the furnace, the furnace cannot be maintained in a reducing atmosphere, and the furnace becomes an oxidizing atmosphere, and graphite is mainly used. Problems such as oxidative consumption of the electrodes 22 and the like occur. In addition, the slag 2 which the worker solidified by human power
Removal of 6 'requires considerable labor, is extremely dangerous work, and has a problem that workability and safety are poor. Further, when the solidified slag 26 ′ is removed by using a machine, there is a problem in heat resistance of the machine because the machine is used in a high-temperature atmosphere. There is a problem of being restricted.

The present invention has been made in view of the above problems, and an object of the present invention is to reliably remove slag adhered to a slag port of a melting furnace and reduce running costs. It is an object of the present invention to provide a slag removing apparatus for a melting furnace which is excellent in handling property and safety.

[0011]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a molten material supplied to a furnace is melt-processed into molten slag, and the molten slag is discharged. What is claimed is: 1. A slag removing device for removing slag adhered to a slag port of a melting furnace which overflows from a slag port, wherein the slag removing device is provided near the slag port and fixed to the slag port. A blasting device that sprays granular blasting material to the blasting device, and a blasting material supply device that supplies the granular blasting material to the blasting device by pressurized fluid, from the blasting device to the slag fixed to the slag port. It is characterized in that the granular abrasive is sprayed together with the pressurized fluid, and the slag fixed to the slag port is scraped off by the granular abrasive.

According to a second aspect of the present invention, there is provided a polishing material supply device, comprising: a supply pipe connected to a blast device; and a supply pipe connected to the supply pipe to store granular polishing material and to supply the abrasive material. A pressurized tank for supplying the supply pipe, a pressurized fluid supply source connected to the supply pipe and supplying a pressurized fluid to the blast device and the pressurized tank, and a control valve interposed in the supply pipe; By controlling the control valve, the abrasive material in the pressurized tank is supplied with pressure to the blast device together with the pressurized fluid.

According to a third aspect of the present invention, the abrasive is made of granulated slag, granulated metal or sand used for surface treatment of steel, and the pressurized fluid is high-pressure nitrogen or high-pressure compressed air. It is characterized by consisting of

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an example of an overflow tapping type electric melting furnace 2 provided with a slag removing device 1 according to an embodiment of the present invention. In FIG. Type melting furnace, 3 is a graphite main electrode, 4 is a slag port, 4a is an inlet of the slag port 4, 4b is an outlet of the slag port 4, 5 is a slag tapping gutter, 6 is a molten slag,
6 'is a solidified slag, 7 is a blasting device, 8 is a polishing material supply device, 9 is a supply pipe, 10 is a pressurized tank, 11 is a polishing material, 12 is a pressurized fluid supply source, 13 is a control valve, G is a pressurized fluid.

The electric melting furnace 2 melts incineration residues and fly ash discharged from incinerators such as municipal solid waste and industrial waste by electric energy,
The molten slag 6 in the furnace overflows from the slag port 4, and the high-temperature exhaust gas generated in the furnace is guided to a secondary combustion chamber (not shown). The inside of the electric melting furnace 2 is kept in a reducing atmosphere in order to prevent oxidation of the graphite main electrode 3 and the like.
An inert gas such as nitrogen gas is continuously supplied into the furnace from an inert gas supply device such as a SA nitrogen production device. Further, the slag port 4 for overflowing the molten slag 6 is
It is formed by surrounding a downslope slag tapping gutter 5 formed in a gutter shape with a refractory having excellent heat resistance or the like by a furnace wall 2a, and a molten slag 6 in the furnace is formed into an inlet 4a of a slag port 4.
Flows into the slag outflow gutter 5 from the side, flows down in the slag outflow gutter 5, and is dropped and discharged from the outlet 4 b side of the slag port 4. Below the slag port 4 is a slag port 4.
Slag cooling water tank (not shown) which cools molten slag 6 dropped and discharged from cooling water by cooling water to form granulated granulated slag
Is arranged.

The slag removing device 1 according to the embodiment of the present invention, when the molten slag 6 overflowing from the slag port 4 of the electric melting furnace 2 adheres to the slag port 4 and solidifies, The fixed slag 6 'is removed to prevent the slag 6' from blocking the slag port 4.
That is, the slag removing device 1 is a blast device 7 for spraying a granular abrasive 11 to the slag 6 ′ fixed to the slag port 4.
And an abrasive supply device 8 for supplying a granular abrasive 11 to the blast device 7 by the pressurized fluid G, and the granular abrasive 11 is supplied from the blast device 7 to the slag 6 ′ fixed to the slag outlet 4. Of abrasive material 11 together with the pressurized fluid G
The slag 6 ′ adhered to the surface is scraped off by the granular abrasive material 11.

More specifically, a plurality of (two in this example) blast devices 7 are provided in the furnace wall 2a near the slag port 4 of the electric melting furnace 2 in a penetrating state. Near the inlet 4a and near the outlet 4b of the slag port 4 where the molten slag 6 tends to adhere and solidify the granular abrasive material 11 supplied under pressure from the provided nozzle (upstream and downstream portions of the slag tapping gutter 5). ). Note that, for the abrasive material 11, granular granulated slag having the same properties as the molten slag 6 discharged from the electric melting furnace 2 is used in terms of effective use of the slag 6 '. Thus, it is possible to prevent the properties and the like of the molten slag 6 discharged from the electric melting furnace 2 from changing, and to hinder the effective use of the slag.

On the other hand, the abrasive material supply device 8 includes a supply pipe 9 for the abrasive material 11 and the pressurized fluid G connected to both blasting devices 7, and a branched connection to the supply pipe 9, and a granular abrasive material supply device 8. A pressurized tank 10 that stores the cleaning material 11 and supplies the polishing material 11 into the supply pipe 9, and is connected to the supply pipe 9,
A pressurized fluid supply source 12 for supplying a pressurized fluid G to the blast device 7 and the pressurized tank 10, and a control valve 13 interposed in the supply pipe 9. The cleaning material 11 in the tank 10 is supplied to the blast device 7 under pressure together with the pressurized fluid G.
The pressurized fluid supply source 12 includes a nitrogen producing device for producing high-pressure nitrogen, and supplies the high-pressure nitrogen produced by the nitrogen producing device to the blast device 7 and the pressurized tank 10 as the pressurized fluid G. ing. The reason why high-pressure nitrogen is used as the pressurized fluid G is that the inside of the electric melting furnace 2 is kept in a reducing atmosphere. Further, the control valve 13 is interposed in the supply pipe 9 on the inlet side of both blast devices 7,
As the control valve 13, a manual open / close valve or an electric open / close valve is used. When a manual open / close valve is used as the control valve 13, the operator manually controls the open / close of the open / close valve arbitrarily according to the growth of the slag 6 'fixed to the slag port 4. When an on-off valve of the type is used, the on-off valve is automatically controlled to open and close at regular intervals.

Thus, according to the electric melting furnace 2 provided with the slag removing device 1 described above, the melted material such as incineration residues and fly ash from the incinerator supplied into the furnace is converted by electric energy. The molten slag 6 is heated to a temperature exceeding the melting point, and becomes a high-temperature liquid molten slag 6. The molten slag 6 overflows sequentially from the entrance 4a side of the slag outlet 4, and flows into the slag tapping gutter 5
After falling down into a slag cooling water tank (not shown) filled with cooling water, it is rapidly cooled and solidified by the cooling water to form granular granulated slag, and then carried out by a water ring type slag conveyor (not shown). Is done.

The high-temperature exhaust gas generated by the melting of the material to be melted enters a secondary combustion chamber (not shown) through a flue, where the secondary combustion air and the like are added. The unburned gas inside is completely burned. After the combustion exhaust gas that has been completely burned is cooled by cooling air or the like,
It is released to the atmosphere via an exhaust gas treatment device (not shown).

Incidentally, in the electric melting furnace 2 of the overflow tapping system, when the overflow amount of the molten slag 6 is reduced or when the temperature in the furnace is reduced, the molten slag 6 overflowing from the slag port 4 is reduced. Is cooled and adheres and solidifies in the vicinity of the outlet 4b and the entrance 4a of the slag port 4, and in the worst case, the slag 6 'fixed to the slag port 4 closes the slag port 4 and the molten slag 6 In some cases, it hindered slag.

In order to prevent such a situation from occurring, before the slag 6 ′ fixed to the slag port 4 by the slag removing device 1 provided in the electric melting furnace 2 closes the slag port 4. The slag 6 'is removed. That is, in the slag removing device 1, when the control valve 13 provided in the supply pipe 9 is manually or automatically opened when the molten slag 6 adheres and solidifies to the slag port 4, the pressure tank 10 Abrasive material 11 (granular granulated slag) stored in the blast device 7 is supplied to the blast device 7 through the supply pipe 9 by the pressurized fluid G (high-pressure nitrogen) from the pressurized fluid supply source 12. The pressurized fluid flows from the nozzle at the tip of the blasting device 7 to the slag 6 ′ fixed to the slag port 4 (the slag 6 ′ fixed to the upstream and downstream portions of the slag tapping gutter 5). Injected with G. Thereby, the slag 6 ′ fixed to the slag port 4 is gradually scraped off by the granular abrasive material 11 sprayed from the blast device 7, and is completely removed from the slag port 4. Therefore, the molten slag 6 in the furnace is
Overflow from the slag port 4 is smooth and satisfactory.

In this slag removing device 1, since granulated granulated slag having the same properties as the molten slag 6 discharged from the electric melting furnace 2 is used as the abrasive material 11,
It is possible to prevent the properties and the like of the molten slag 6 discharged from the electric melting furnace 2 from changing, and it does not hinder the effective use of the slag. Further, since high-pressure nitrogen is used for the pressurized fluid G, even if the electric melting furnace 2 is operated while maintaining the inside of the furnace in a reducing atmosphere, the pressurized fluid G is introduced into the furnace.
Is supplied, the inside of the furnace does not become an oxidizing atmosphere, and the oxidative consumption of the graphite main electrode 3 and the like can be prevented.

In the above embodiment, the abrasive 1
Although granular granulated slag is used as 1, in another embodiment, granular granulated metal or steel discharged from the electric melting furnace 2 and cooled as the abrasive 11 is used. Sand or the like used for surface treatment may be used.

In the above-described embodiment, a nitrogen producing apparatus is used as the pressurized fluid supply source 12, and high-pressure nitrogen produced by the nitrogen producing apparatus is supplied as the pressurized fluid G. In the case of the electric melting furnace 2 which does not need to be operated in a reducing atmosphere in the furnace, a compressor is used as the pressurized fluid supply source 12, and high-pressure compressed air is supplied as the pressurized fluid G from the compressor. You may do it.

Further, in the above embodiment, two blasting devices 7 are provided near the slag outlet 4, but in other embodiments, the blasting devices 7 are provided near the slag outlet 4. 7 may be provided as one or three or more.

[0027]

As is clear from the above description, the slag removing apparatus of the present invention blasts the granular abrasive material stored in the pressurized tank together with the pressurized fluid from the pressurized fluid supply source. Injection is performed from the device toward the slag fixed to the slag port of the melting furnace, and the slag fixed to the slag port is scraped off with a granular abrasive material. The slag that has adhered to the slag outlet can be more reliably removed as compared with the case where the slag that has adhered to the slag outlet is remelted by combustion heat. In addition, when the slag removing device of the present invention is used, it is not necessary for an operator to remove slag solidified by manual labor, and the labor can be reduced. Needless to say, there is no need for the operator to directly engage in the slag removal work, and the safety is excellent. Furthermore, the slag removal device of the present invention removes slag adhered to the slag port with a particulate abrasive, so that a large amount of fuel is required when an auxiliary burner is used as in the prior art. It is possible to reduce the running cost without saying. Further, the device itself can be simplified as compared with the device using the auxiliary burner, and the handling can be facilitated. In addition, the slag removing apparatus of the present invention can use granulated slag or granulated metal generated from a melting furnace as a polishing material, which is extremely convenient. In particular, when granulated slag is used as a polishing material, it is possible to prevent the properties and the like of the slag discharged from the melting furnace from changing, and it does not impede effective use of the slag. . In addition, the slag removing apparatus of the present invention is such that when nitrogen is used as the pressurized fluid, the furnace is maintained in a reducing atmosphere even in an electric melting furnace which operates in a reducing atmosphere in the furnace. As a result, oxidative consumption of the graphite main electrode and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of an overflow tapping type electric melting furnace provided with a slag removing device according to an embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view of an overflow type electric melting furnace provided with an auxiliary burner.

[Explanation of symbols]

1 is a slag removal device, 2 is a melting furnace (electric melting furnace), 4
Is a slag outlet, 6 is a molten slag, 6 ′ is a solidified slag, 7
Is a blasting device, 8 is an abrasive supply device, 9 is a supply pipe,
10 is a pressurized tank, 11 is a polishing material, 12 is a pressurized fluid supply source, 13 is a control valve, and G is a pressurized fluid.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yoshito Fukuma 2-33, Kinrakuji-cho, Amagasaki-shi, Hyogo F-term in Takuma Co., Ltd. (Reference) 3K061 NB02 NB13 NB15 NB23 NB27 4K045 AA07 BA10 RC11 RC20 4K055 AA05 LA06

Claims (3)

[Claims] 1. A molten material supplied into a furnace is subjected to a melting treatment to form a molten slag, and the slag fixed to the slag port of the melting furnace in which the molten slag overflows from a slag port is removed. A slag removal device, wherein the slag removal device is provided near the slag port, and a blast device that sprays a granular abrasive to the slag fixed to the slag port,
An abrasive material supply device that supplies granular abrasive material to the blasting device by pressurized fluid, and the granular abrasive material is mixed with the pressurized fluid from the blast device to the slag fixed to the slag port. A slag removal device for a melting furnace, characterized in that slag fixed to the slag port is scraped off by a granular abrasive. 2. An abrasive supply device is connected to a supply pipe connected to a blast device, and is connected to the supply pipe to store granular abrasive material and pressurize the supply of the abrasive material into the supply pipe. A tank, a pressurized fluid supply source connected to the supply pipe and supplying a pressurized fluid to the blast device and the pressurized tank, and a control valve interposed in the supply pipe, by controlling the control valve, 2. The slag removing device for a melting furnace according to claim 1, wherein the abrasive material in the pressurized tank is supplied to the blast device under pressure together with the pressurized fluid. 3. The abrasive material is made of granulated slag, granulated metal or sand used for surface treatment of steel material, and the pressurized fluid is made of high-pressure nitrogen or high-pressure compressed air. The slag removing device for a melting furnace according to claim 1 or 2.