JP2002122319A - Equipment for treatment of granulated slag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent contamination of granulated slag in case of granulating molten slag of incineration ash with water. SOLUTION: Molten slag 23 discharged from a slag runner 19 of an ash- melting furnace 1 is dropped in a slag-granulation basin 26 in slag-granulation equipment 25. A slag-granulation conveyor 27 is provided to the basin 26. A granulated-slag discharge port 29 is provided in the upper part of the slant 26b of the basin 26 and lower face of the upper part of the conveyor 27. A spray 31 is provided on the wall 30 for washing granulated slag so as to spray washing water between the slant 26b and the conveyor 27. A detector 35 is provided in the basin 26 to detect the water amount of the basin 26, and water is supplied to the basin 26 in accordance with an decrease in the cooling water 28 in the basin 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for granulating molten slag in a ash melting furnace which melts incinerated ash such as refuse and recycles or reduces slag incinerated ash. The present invention relates to a granulated slag processing device capable of removing dirt from the granulated slag.

[0002]

2. Description of the Related Art Ash melting furnaces are used to make effective use of refuse incineration ash. The incineration ash melted by the ash melting furnace is divided into low-boiling volatile matter, slag of metals and other components. , Detoxifying and recycling it. The need for such incineration ash melting furnaces is increasing. FIG. 3 shows a conventional plasma arc ash melting furnace 51 and a granulated slag processing apparatus 61. In the ash melting furnace 51, a main electrode 52 of a plasma electrode is provided on the furnace chamber side, and a furnace bottom electrode 53 is provided on the furnace bottom side. In the ash melting furnace 51, a slag port 54, which is an outlet for molten slag, is provided.
The slag port 55 is connected to a slag gutter 55.

FIG. 4 shows the vicinity of a slag port 54 of an ash melting furnace 51. On the side wall 56 of the ash melting furnace 51, the above-mentioned slag port 54 is provided at a position slightly higher than the furnace bottom wall 57. The slag 70 obtained by heating and melting the incinerated ash and the metal 69 in which the metal component in the incinerated ash is accumulated on the furnace bottom wall 57, and the slag 70 accumulated on the furnace bottom increases and overflows at the slag outlet 54. This serves to discharge the slag 70. A granulation tank 62 for granulating (water cooling) the molten slag is disposed below the tip of the slag gutter 55.
The granulating tank 62 is provided with a granulating conveyor 63 for transferring granulated slag 65 from the granulating tank 62 to the outside of the granulated slag processing device 61, and a slag discharge port 64 is provided at the upper end side of the granulated conveyor 63.
Are arranged.

With such a configuration, when incineration ash is put into the furnace chamber of the ash melting furnace 51 and a voltage is applied to the plasma electrodes 52 and 53, a plasma arc is generated between the electrodes 52 and 53, and the incineration ash is generated. Is heated to form a molten slag 70, which accumulates in the furnace bottom and reaches the height of the slag port 54, and the slag overflows from the slag port 54, passes through the slag gutter 55, and flows into the granulation tank 62. To form granular granulated slag 65. The granulated slag 65 is transported upward with the rotation of the granulated conveyor 63 and discharged from the outlet 64 of the granulated slag 65. At this time, when the cooling water 66 flows down to the molten slag 70, the cooling water 66 evaporates due to the heat of the molten slag 70. Therefore, the water supply port 67 for supplying the cooling water 66 is provided in the granulation tank 62. ing. On the other hand, the gas generated during the operation is exhausted from the exhaust port 58 and made harmless by an exhaust gas treatment device provided in the next step.

[0005]

As shown in FIG. 4, as shown in FIG.
No. 8 is in an environment where the temperature is low due to being less affected by the plasma heat. Therefore, when the combustion gas comes into contact with these walls, the combustion gas reacts to generate dissolved salts of NaCl and KCl, and the upper wall 5
In some cases, the dissolved salt 71 containing a heavy metal adheres to the exhaust port 9 and the exhaust port 58. The dissolved salt 71 is separated from the side wall portion 60 and falls into the cooling water 66, or a combustion gas or the like containing a heavy metal contacts the cooling water 66 in the granulation tank 62 through the exhaust port 58,
The cooling water 66 may be contaminated. The dissolved salt and the like mixed in the cooling water 66 of the granulation tank 62 do not evaporate, and if the operation of the ash melting furnace 51 is continued as it is, the salt concentration and the like in the water increases, which adheres to the surface of the granulated slag 65. I do.

Further, as shown in FIG. 4, in the ash melting furnace 51, when incinerated ash is supplied onto the molten slag 70, the incinerated ash is melted on the surface of the molten slag 70 due to fluctuations in the amount of supplied ash and the properties of the ash. Unmelted incinerated ash 72 may float and be discharged from the slag port 54. The unmelted incineration ash 72 is not detoxified, and if it is mixed into the cooling water 66 of the granulation tank 62, the cooling water 66 is contaminated and the granulated slag 65
There is a case where contaminants are attached to the surface of the substrate. Therefore, the granulated slag 65 may not be able to meet the elution standard. The present invention has been made in view of such circumstances, and when the molten slag of incinerated ash is subjected to water granulation to form granulated slag, the granulated slag that can prevent contamination of the granulated slag is provided. It is an object to provide a processing device.

[0007]

In order to achieve the above object, the apparatus for treating granulated slag of the present invention uses molten slag discharged from a slag discharge section of an ash melting furnace to cool water in a granulated tank. The granulated slag is generated by performing a water granulation process, and the granulated slag is discharged from the granulated slag to the outside of the granulated tank by a conveyor. A washing spray for washing the crushed slag with water was provided, and the water of the washing spray was supplied into the granulator. In the above invention, a detector for detecting the amount of cooling water in the water granulation tank is provided in the water granulation tank, and the water of the washing spray is supplied to the water granulation tank in accordance with the amount of cooling water in the water tank. It is good to replenish inside.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus for treating granulated slag according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a plasma arc type ash melting furnace 1 according to the present invention. The ash-melting furnace 1 is provided with a furnace chamber 6 surrounded by a furnace side wall 11 formed of refractory bricks, and a main electrode 4 disposed on the furnace chamber 6 side, and a furnace bottom wall 5 side of the furnace chamber 6. There is provided a plasma apparatus including a furnace bottom electrode 7 to be provided and a DC power supply 8 for supplying electricity to these electrodes. The main electrode 4 penetrates through the ceiling wall 3 of the melting furnace body 2 and hangs down.
The furnace chamber 6 is configured to be able to move up and down by being supported by the elevating device 15.

The main electrode 4 is made of metal or graphite, and has a cylindrical shape in which a passage for generating a plasma gas is formed. At the lower end of the main electrode 4, a furnace bottom electrode 7 is installed on a furnace bottom wall 5 facing the tip, and a DC power source 8 for plasma generation is connected between these electrodes 4 and 7. The DC power supply 8 has + connected to the furnace bottom electrode 7 side and − connected to the main electrode 4 side. The melting furnace body 2 includes a furnace side wall 1.
A cooling jacket (not shown) for cooling the refractory brick 1 is provided, and the surroundings are covered with a steel shell 10. On the lower wall portion of the melting furnace main body 2, a slag port 18 which is a discharge port of the molten slag 23 is provided, and a slag gutter 19 is connected to the slag port 18. An ash supply device 2 for injecting incinerated ash supplied from a hopper 20 into a furnace chamber 6 is provided on a furnace side wall 11 of the ash melting furnace 1.
1 is provided.

FIG. 2 shows a device 25 for treating granulated slag according to the present invention, which comprises a granulated tank 26 and a granulated conveyor 27. The granulation tank 26 is equipped with the drain gutter 1
9 and is communicated with a combustion gas exhaust port 16 disposed above the tip of the slag gutter 19. Cooling water 28 is stored in the granulation tank 26, and a horizontal portion 27 a located at the lower end side of the granulation conveyor 27 is disposed along a horizontal surface 26 a which is the bottom at one end of the granulation tank 26. I have. The other end of the granulation tank 26 has an inclined surface 26.
b is formed, and an inclined portion 27b located on the upper end side of the granulating conveyor 27 is provided along the inclined surface 26a. The granulating conveyor 27 has a drive wheel 27 on the inclined portion 27b side.
c and a driven wheel 27d on the horizontal portion 27a side, and an endless belt 27e is wound around these peripheral portions. A number of scraping claws 27f are attached to the outer periphery of the endless belt 27e, and the endless belt 27e can rotate in the direction of arrow a by the driving force of the driving wheel 27c.

An outlet 2 for the granulated slag is provided above the inclined surface 26b of the granulated tank 26 and on the lower surface above the granulated conveyor 27.
9 are formed. A cleaning spray 31 is provided on a wall portion 30 of the discharge port 29 facing the falling portion of the granulated slag, and a spray angle of the cleaning spray 31 is controlled by a control unit 36 so that the spray angle can be adjusted vertically. The cleaning water is sprayed between the inclined surface 26b and the lower surface of the granulating conveyor 27. An opening / closing valve 32 is connected to the cleaning spray 31 via a pipe line.
Is connected to a supply source 33 of distilled water or tap water. The granulation tank 26 is provided with a detector 35 for detecting the amount of water stored in the cooling water 28, and the detector 35 is connected to the control unit 36,
The control unit 36 is configured to be able to adjust the opening of the on-off valve 32. The ash melting furnace 1 is provided with a control device (not shown) for controlling plasma and the like, a gas supply facility for generating plasma, and many other devices. Similarly, the granulated slag processing device 25 is also provided with other devices. Are provided, but detailed description thereof is omitted.

Next, the operation of the embodiment of the present invention will be described. As shown in FIG. 1, the furnace chamber 6 of the ash melting furnace 1 includes:
From the hopper 20 via the ash supply device 21, the furnace bottom wall 5
The incineration ash is put on top. In the furnace chamber 6 of the ash melting furnace 1, a voltage is applied between the plasma electrodes 4 and 7 by the DC power supply 8 in a state where the furnace chamber 6 is in a reducing atmosphere. Then, a plasma arc is generated between the electrodes 4 and 7, and the inside of the furnace chamber 6 becomes 100 arc.
The atmosphere becomes 0 ° C. or higher, and melting of the incinerated ash starts.

In the incineration ash melting operation, the incineration ash is heated and melted by the heat of the plasma arc to form a molten slag 23. Similarly, the metal component contained in the incineration ash is melted to form a molten metal 24, and a specific gravity is obtained. The light slag 23 rises to the upper part, and the metal 24, which has a higher specific gravity,
Sink at the bottom of 3. Slag 23 accumulates in the furnace bottom and slag port 18
The slag 23 overflows from the slag port 18, passes through the slag gutter 19, and flows down to the cooling water 28 in the granulation tank 26. The high-temperature molten slag 23 is rapidly cooled by the cooling water 28 to become granulated slag 34 which is a lump on the granules. The granulated slag 23 is a scraping claw 27 of a granulated conveyor 27.
By being disposed between f, the endless belt 27e is rotated to transfer from the horizontal surface 26a of the granulation tank 26 onto the inclined surface 26b, and is discharged from the discharge port 29. Granulated slag 34
Are washed at the outlet 29 with distilled water sprayed by a washing spray 31. At this time, even if the cooling water 28 in the granulation tank 26 is contaminated with the dissolved salt, unmolten incinerated ash, combustion gas, or the like as described in the section of the prior art and adheres to the surface of the granulated slag 34, distillation is performed. Can be washed with water.

When the molten slag 23 is solidified as granulated slag 34, the slag 23
g of cooling water evaporates, and it is necessary to replenish the cooling water drained according to the amount of evaporation (if the water is drained due to other circumstances, the amount of decrease is also added). In the form, when the water of the cleaning spray 31 is sprayed to the granulated slag 34, the water is sprayed between the inclined surface 26b and the granulated conveyor 27, so that the cleaning water enters the granulated tank 26. , Can be supplemented with cooling water. Since the detector 35 can detect the amount of water stored in the granulation tank 26 or the liquid level, the controller 36 can adjust the opening degree of the on-off valve 32 to adjust the amount of cooling water.
Alternatively, the cleaning spray 31 may be smaller than the evaporation amount of the cooling water 28.
In the state where the injection amount is large, the inclination angle of the cleaning spray 31 can be set slightly downward by a command from the control unit 36 to prevent the cleaning water from entering the granulation tank 26. Conventionally, the water supply port 67 for supplying the evaporation of the cooling water is provided. However, in the present embodiment, the water supply port 67 can be omitted or the water supply port 67 can be supplemented.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention. For example, in the above embodiment, a plasma type ash melting furnace is described as an example, but a burner type ash melting furnace using heavy oil or the like as a fuel for melting incinerated ash, or a resistance type ash using electricity as a heating source. It can also be used for melting furnaces. Further, in the above embodiment, distilled water or tap water was supplied from the washing spray in accordance with the reduced amount of the cooling water in the granulator, but a part of the reduced amount was replenished without supplying the entire reduced amount. You may make it.

[0016]

As described above, according to the apparatus for treating granulated slag of the present invention, the molten slag discharged from the slag discharge section of the ash melting furnace is granulated by the cooling water in the granulation tank. A granulated slag, and discharges the granulated slag to the outside of the granulation tank by a conveyor. The granulated slag is discharged to the discharge section of the granulated slag of the conveyor. Since the washing spray is provided and the water of the washing spray is supplied into the granulator, the granulated slag contaminated in the granulator can be washed. Further, a detector for detecting the amount of cooling water in the granulating tank is provided in the granulating tank, and the water of the cleaning spray is introduced into the granulating tank according to the amount of cooling water reduced in the water tank. Since replenishment is performed, the cooling water in the granulation tank that evaporates when the molten slag is granulated can be replenished.

[Brief description of the drawings]

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

FIG. 2 is a schematic cross-sectional view of a granulated slag processing device provided in a lower part of the ash melting furnace in the embodiment.

FIG. 3 is a schematic cross-sectional view of a conventional apparatus for treating granulated slag disposed below a ash melting furnace.

FIG. 4 is an enlarged sectional view of a slag port of the ash melting furnace of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma arc ash melting furnace 2 Melting furnace main body 3 Ceiling wall 4 Main electrode 5 Furnace bottom wall 6 Furnace room 7 Furnace bottom electrode 8 DC power supply 10 Iron shell 11 Furnace side wall 15 Elevating device 16 Exhaust port 18 Slag port 19 Dust Gutter 20 hopper 21 ash supply device 23 molten slag 24 molten metal 25 granulated slag processing device 26 granulated tank 26a horizontal surface 26b inclined surface 27 granulated conveyor 28 cooling water 29 outlet 30 wall 31 washing spray 32 opening and closing valve 33 distillation Water supply source 34 Granulated slag 35 Detector 36 Control unit

Claims (2)

[Claims] The slag discharged from a slag discharge section of an ash melting furnace is granulated by cooling water in a granulating tank to produce granulated slag, and the granulated slag is conveyed by a conveyor to the granulated slag. In the apparatus for treating granulated slag discharged to the outside of the tank, a washing spray for washing the granulated slag with water is provided at a discharge section of the granulated slag of the conveyor, and the water of the washing spray is discharged to the water. An apparatus for treating granulated slag, wherein the granulated slag is supplied into a crushing tank. 2. A detector for detecting an amount of cooling water in the granulating tank is provided in the granulating tank, and the water of the washing spray is granulated according to a reduction amount of the cooling water in the tank. The apparatus for treating granulated slag according to claim 1, wherein the tank is replenished.