JPH11159737A - Melting furnace and manufacture of slug using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture slug, having proper strength, water absorption, and a constant size, by a small furnace. SOLUTION: A combustible substance, such as city refuse and industrial waste, is gasified and discharged toward above and ash contents, such as incinerated ash and flying ash, is converted into a melting slag 11 and dropped through a drop opening 2, and a melting furnace 1 is provided to generate the slug 21 by cooling molten slug 11. A rotating rotor 3 is arranged internally below the drop opening 2 and the rotor 3 collides the dropping molten slug 11 with an opposite water-cooled wall 5 through the rotation force of the molten slug 11 for crush, and a control mechanism is provided to produce slug 21, having given grain size, strength, and water absorption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the incineration of combustible materials such as municipal solid waste or industrial waste, and more particularly to a melting furnace for melting and burning ash and fly ash produced thereby, and a slag using the furnace. And a method for producing the same.

[0002]

2. Description of the Related Art In a conventional melting furnace, flammable substances such as municipal solid waste, industrial waste or fine solid carbonaceous material are gasified, and ash such as incineration ash and fly ash are melted to form a molten slag. It is a structure that falls down and cools the molten slag to produce slag, and also includes a pulverized coal gasifier. The molten slag is collected as quenched slag by water cooling or gradually cooled slag by air cooling. From the viewpoint of resource recycling of the slag, it is desirable that the slag be appropriately crystallized to have high strength and be recovered as slag having an appropriate water absorption. As a method for this, a method shown in FIG. 2 is generally used. In this method, a molten slag 11 melted in a melting furnace 10 falls from a tuyere (fall port) 12 and falls on a bucket 14 in a bucket conveyor 13. The slag 12 is blocked by slowly moving the bucket 14 and cooling it during that time. This slag 21 falls onto the carry-out conveyor 16 via the slag discharge port 15 and is collected as slowly cooled slag. However, this method requires a large cooling conveyor, a complicated structure, and a large installation space.

[0003] The slag produced by this method has sufficient strength, but has a drawback of low water absorption. In addition, it is necessary to grind the slag to an appropriate size to use it, and slag with sharp corners is obtained by crushing. There were drawbacks needed. In addition, fine powder of slag is generated in the pulverization process, and thus there is a disadvantage that the utilization rate of the generated slag is reduced. Further, when slag is collected and cooled on such a large bucket, there is a problem that physical properties are likely to be different between the surface and the inside of the slag. As a method of solving such a problem of the slow cooling slag, there is a method of flowing molten slag onto a rotating disk horizontally disposed below the lower part of the slag (see Japanese Utility Model Registration No. 2513905). However, in this method, the slag is indirectly cooled on the rotating disk, and the slag is scraped and dropped by the scraper.Therefore, there is a structural problem for holding the slag on the rotating disk for a certain period of time, and the slag does not have a uniform size. There were drawbacks.

[0004] Further, a rotary drum having a recess (pan) of an appropriate size is provided below the lower part of the slag flow, and once the slag is received therein, the slag is dropped downward according to the rotation of the drum, and the massive slag is removed. There is a method of producing (see Japanese Utility Model Laid-Open No. 57-66326, microfilm). With this method, it is possible to obtain a relatively small and uniform-sized lump of slag as compared with the conventional method shown in FIG. 2, but in order to use it as a highly available coarse or fine aggregate, ,
Again, pulverization is necessary, and there is a problem similar to the case where a block of slow cooling slag manufactured by the method shown in FIG. 2 is used.

[0005]

In the conventional melting furnace, in order to recycle the slag after the slow cooling, it is necessary to perform a pretreatment to make the crushed slag into a safe shape for use. Since the size of the is not constant, a classification operation is required for use. In addition, there is a problem that the manufacturing apparatus becomes large, and the generated slag has strength when the slowly cooled slag is used, but has a lower water absorption than natural aggregate, while the quenched slag tends to have a low strength.

SUMMARY OF THE INVENTION An object of the present invention is to provide a melting furnace capable of producing slag having appropriate strength and water absorption and a constant size in a small-sized furnace, and a method for producing slag using the furnace. It is in.

[0007]

In order to achieve the above object, a melting furnace according to the present invention gasifies combustibles, melts ash, drops molten slag from a drop port, and cools the molten slag. In a melting furnace that generates slag, a rotating rotor is installed vertically below the drop port so that it can move up and down, and the rotating rotor crushes the falling molten slag by rotating it against the opposing water cooling wall. And a control mechanism for generating a predetermined slag.

The control mechanism controls the number of rotations of the rotating rotor, moves the rotating rotor up and down, and injects a cooling medium from at least one nozzle inserted into the water cooling wall. May be used.

A hopper may be connected to the lower part of the water cooling wall, and a rotary valve may be provided at the lower part of the hopper to seal the inside of the furnace and discharge the slag with the rotary valve.

Further, in the method for producing slag, the molten slag is dropped on a rotating rotor below a dropping port by using any one of the above-mentioned melting furnaces, and the molten slag is cooled by the rotating force of the rotating rotor. And crushed by a control mechanism to control at least the rotation speed of the rotating rotor to generate a predetermined slag.

According to the present invention, since the rotary rotor is provided below the molten slag dropping port, the molten slag is collided with the water cooling wall by the rotational force of the rotary rotor, is pulverized and cooled, and has a predetermined particle size. And a slag having strength and water absorption.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. As shown in Fig. 1, the melting furnace gasifies combustibles such as municipal solid waste or industrial waste or finely divided solid carbonaceous raw materials and discharges them upward, and also melts ash such as incineration ash, fly ash and combustion ash. This is a melting furnace 1 which is converted into slag 11 and falls from a dropping port (tuyere) 2 to cool the molten slag 11 to produce a slag 21, and the rotating rotor 3 is vertically movable below the dropping port 2. Internally installed rotating rotor 3
Is provided with a control mechanism (not shown) for causing the falling molten slag 11 to collide with the opposing water-cooling wall 5 by rotational force and pulverize to generate a slag 21 having a predetermined particle size, strength and water absorption. Configuration. This embodiment is also applicable to a pulverized coal gasifier. The control mechanism controls the number of rotations of the rotary rotor 3 and moves the position of the rotary rotor up and down. At least one of the nozzles 4 and 6 inserted into the water cooling wall 5 supplies water or air. This is to inject a cooling medium.

That is, the incineration ash, fly ash or combustion ash is melted in the melting furnace 1, becomes molten slag 11, overflows from the tuyere 2 and flows down. The rotating rotor 3 is provided below the tuyere 2, and the molten slag 11 is dropped on the rotating rotor 3. The rotating rotor 3 has teeth 3a perpendicular to the rotating direction R.
The one with the mark is more efficient, but a simple cylinder or a cylinder with a thin groove formed on the surface or a small irregularity may be used.

The incineration ash, fly ash or combustion ash is generally 125
Although it is molten at 0 to 1450 ° C., the molten slag 11 does not adhere to the surface of the rotating rotor 3 as long as the surface temperature of the water cooling wall 5 is kept at 500 ° C. or less. Therefore, the rotating rotor 3 is cooled by injecting air or water from a nozzle 4 inserted into the furnace wall on the back surface of the rotating rotor 3, or the rotating rotor 3 is formed into a hollow drum, and cooling water is supplied to the inside thereof. ,
What is necessary is just to keep surface temperature below 500 degreeC. The rotating rotor 3 causes the molten slag dropped on the rotating rotor 3 to collide with the opposed water-cooling wall 5 by its rotating force. Water cooling wall 5 facing
Has a cooling structure in which water or air is circulated in the buried pipe 5a and is kept at a low temperature, so that the adhesion of the molten slag 11 is prevented and the surface of the water cooling wall 5 is corroded. Can be prevented. For example, a signal of the surface thermometer of the water cooling wall 5 is input to the control mechanism, and the surface temperature becomes 500
When the temperature is higher than or equal to ° C, the amount of water or air in the pipe 5a can be adjusted, and the surface temperature of the water cooling wall 5 can be controlled to a predetermined temperature of 500 ° C or less.

The molten slag 11 that has collided with the water cooling wall 5 is pulverized by the collision force with the water cooling wall 5, and is combined with a slag 21 having a small particle diameter and a uniform size that is highly useful as coarse or fine aggregate. Become. In addition, since the slag 21 crushed by the water cooling wall 5 was cooled to 100 ° C. or less and solidified, the particles of the slag 21 did not adhere to each other. At this time, by inputting data obtained in advance to the control mechanism, the position of the rotary rotor 3 is moved up and down according to the viscosity and the melting point of the molten slag 11, and the particles of the slag 21 to be generated have a desired particle size. Is controlled so that they can be aligned with each other. For example, in order to prepare a slag that is a fine aggregate having a small particle diameter from a molten slag having a high viscosity or a high melting point, the position of the rotating rotor is moved upward and the number of rotations is increased, or either of them is increased. Data to be input may be selected based on the above condition. On the other hand, in order to produce slag that becomes coarse aggregate having a large particle diameter by using the molten slag, the rotating rotor 3 is moved downward or the rotation speed is lowered so that the temperature of the molten slag is slightly lowered. Alternatively, input data may be selected based on both conditions.

By pulverizing into slag in the molten state, the pulverized slag particles become nearly granular due to surface tension. Therefore, there is an advantage that, as in the case of pulverization after forming the slowly cooled slag, pretreatment for equalizing the particle size before use and eliminating sharp corners generated by the pulverization becomes unnecessary. The crushed slag 21 falls to the lower hopper 7. At this time, in order to control the degree of crystallization of the slag 21, it is possible to jet the air from the nozzles 4 and 6 to rapidly cool the slag 21 by inputting it to the control mechanism. In addition, it is also possible to quench the water by injecting water instead of air to form a sandy slag 21.

The slag 2 having a uniform particle size as described above
1 is temporarily held in the hopper 7 as needed. A rotary valve 8 is provided below the hopper 7 to seal the inside of the furnace with the rotary valve 8 and discharge the slag 21 using the rotary valve 8. The slag 21 discharged from the hopper 7 is discharged by the lower unloading device 9.

In the present system, since a sealing mechanism using such a rotary valve can be employed, a conventional large cooling conveyor is not required, and the apparatus can be made compact. The disadvantage of quenching slag by water cooling is that there is no time for the molten slag to crystallize, so the strength is low, the slag has many cracks, and when used as a roadbed material, it may be difficult to obtain slag of a certain strength and size. Was. In the case of the slowly cooled slag according to the method shown in FIG. 2, on the other hand, the crystallization proceeds too much, so that the strength is sufficient, but there are many cases where there is not an appropriate water absorption required for use as a roadbed material. Although it is necessary to crush before use, the crushed slag has a sharp crushing surface, and it is often necessary to slightly reduce the angle due to wear or annealing, but in this production method, the molten slag is transferred to the water cooling wall. Crushed during melting by collision of
Since the slag particles are rounded and have a narrow particle size distribution range, no pretreatment is required for use. Spray air or water while falling from the colliding water cooling wall to the hopper,
Although rapid cooling is possible, fine cracks can be generated between crystals in the rapid cooling process. By adopting such a two-stage cooling process, it is also possible to have the water absorption of the natural roadbed material, the strength of conventional quenched slag is low, while the strength of slowly cooled slag is high, Defects such as the water absorption as an aggregate were too low could be overcome.

As another embodiment of the present invention, a method for producing slag shown in FIG. 1 uses the above-mentioned one of the melting furnaces 1 and drops the molten slag 11 onto the rotary rotor 3. A step of crushing and crushing by colliding with the opposing water cooling wall 5 by the rotating force of the rotating rotor 3 and inputting a control mechanism to control the number of rotations of the rotating rotor 3 or moving the position of the rotating rotor 3 up and down Or a step of injecting water or air cooling medium from at least one nozzle 4, 6 inserted into the water cooling wall 5, and closing or opening the rotary valve 8 to seal or open the furnace. And discharging the generated slag 21 having a predetermined particle size, strength and water absorbability.

According to the present invention, it is possible to suppress the complexity and size of the apparatus, to make it possible to produce slag having a constant particle size, to eliminate the need for pretreatment before use, and to achieve two-stage cooling, which is similar to natural roadbed material. It is now possible to manufacture slag with moderate strength and water absorption.

[0021]

According to the present invention, since the molten slag is crushed and collided with the water cooling wall by the rotating force of the rotating rotor, it has strength and water absorption with a predetermined particle size by a downsized furnace. Slag can be generated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,10 Melting furnace 2,12 Drop port 3 Rotary rotor 4,6 Nozzle 5 Water cooling wall 7 Hopper 8 Rotary valve 9,16 Carry-out conveyor 11 Melting slag 21 Slag

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23J 1/00 F23J 1/00 C B09B 3/00 303L

Claims (6)

[Claims] 1. A melting furnace for gasifying combustibles, melting ash, dropping molten slag from a dropping port, and cooling the molten slag to produce slag, wherein a rotating rotor is provided below the dropping port. The rotating rotor is provided so as to be movable up and down, and the rotating rotor is provided with a control mechanism that collides the falling molten slag with an opposing water cooling wall by a rotational force to pulverize the molten slag to generate a predetermined slag. Melting furnace characterized. 2. The melting furnace according to claim 1, wherein the control mechanism controls the number of revolutions of the rotary rotor. 3. The melting furnace according to claim 1, wherein
A melting furnace, wherein the control mechanism moves the position of the rotary rotor up and down. 4. The melting furnace according to claim 1, wherein the control mechanism causes the cooling medium to be injected from at least one nozzle inserted into the water cooling wall. 5. The melting furnace according to claim 1, wherein a hopper is connected to a lower portion of the water cooling wall, and a rotary valve is provided at a lower portion of the hopper, and the inside of the furnace is sealed by the rotary valve. A melting furnace characterized by discharging slag. 6. A water cooling method using the melting furnace according to any one of claims 1 to 5, wherein the molten slag is dropped onto a rotating rotor below a dropping port, and the molten slag is opposed by the rotating force of the rotating rotor. A method for producing slag, wherein the slag is crushed by colliding with a wall and a predetermined slag is generated by controlling at least the number of revolutions of the rotary rotor by a control mechanism.