JP2003074828A - Melting device for ash - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eminently improve durability even when the device is used at a high temperature of 1600-1700 deg.C or higher for a long time, solve the problem that a molten ash in the vicinity of discharge port 13 is cooled and soilidied for choking and the melting furnace can not be used, improve thermal efficiency and lower fuel consumption by improving heat insulation ability of a furnace wall, and further facilitate replacement of crucible in a short time. SOLUTION: A three-layer structure crucible is used, an auxiliary burner is used to prevent lowering of the temperature in the vicinity of a discharge port 13, durability is improved by improving heat insulation ability by employing a furnace wall of four-layer structure, and a means to facilitate taking-out of the crucible by mounting covers on both sides is employed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ash melting apparatus, and particularly to detoxify incinerator ash produced by incineration of industrial waste, household waste, etc., and make it reusable. It relates to an extremely efficient and miniaturizable device for melting incineration ash for slagging, agglomeration or fibrosis.

[0002]

2. Description of the Related Art In recent years, dioxin, heavy metals, injection needles, etc., contained in incinerated ash waste after incinerating waste discharged from homes, factories, hospitals, etc. are thrown into the environment and pollute the environment. It has become a big social problem, and a means for treating these wastes is required.

As a means for treating the above-mentioned incinerated ash waste, a method of melting and solidifying, reducing and detoxifying is disclosed. For example, Japanese Patent Application No. 2000-324734 discloses an ash melting apparatus shown in FIG. A lid provided with a burner unit 3 using petroleum gas such as propane gas, butane gas, or city gas and oxygen gas as fuel in a central portion of a furnace body 1 having an exhaust port 13 and an ash input port 5 Disclosed is an apparatus for melting ash, characterized in that, in a furnace including two, the innermost layer of the furnace body 1 has a replaceable single-layer crucible 4, and the opening of the crucible 4 is directed to the lid 2 side. ing.

[0004] The patent body will be described in more detail with reference to FIG. 1. The furnace body 1 has a crucible 4, a fluid sand 11, a first heat-resistant layer 8, a second heat-resistant layer 9, a third heat-resistant layer from the innermost wall. 10, an iron skin 12, an ash charging port 5 is provided at one location near the center of the side surface of the furnace body 1, a crucible protruding rod 6 is provided on the right side surface, and a melt 14 is discharged at the lower left. A discharge port 13 for exhausting gas is provided, a temperature sensor 7 is provided on the upper left side, and a position for dropping the crucible 4 is set so that the melt 14 does not contact the wall surface 16 of the discharge port 13. There is.

The crucible 4 is a heat-resistant type carbon content of 30 to 55%, which is commercially available, for example, from Japan Crucible Co., Ltd.
Using SiC charcoal silicon crucible of SiC 30-50%,
The first heat-resistant layer 8 and the second heat-resistant layer 9 can be made of fire-resistant castables, crucibles, fire-resistant bricks, etc. after being molded into a predetermined size and fired. One with high heat resistance is used. Third heat-resistant layer 10
A board or heat-insulating castable is used.

Like the furnace body 1, the lid 2 is composed of a first heat-resistant layer 8, a second heat-resistant layer 9, a third heat-resistant layer 10 and a steel shell 12 from the inside, a burner 3 is provided in the central portion, and it is on the side surface. As shown in FIG. 1, it is configured so that it can be opened and closed easily with a hinge and can be opened and closed with a screw or the like, as shown in FIG.

The burner 3 used in the present invention is
It is desirable to use a petroleum gas such as propane gas or butane gas as a fuel, and to completely burn it with a relatively small amount of oxygen gas near the equivalent or air, because the waste gas generated by burning the gas is relatively clean. Since it is blown from the burner 3 at a relatively low pressure, less ash is scattered,
Therefore, the amount of ash contained in the exhaust gas can be reduced, and the ash is introduced near the center of the crucible 4 where the flame from the burner 3 reaches the highest temperature.

In order to operate the melting furnace shown in FIG. 1 of the patent, for example, in the state shown in FIG. 1, for example, a mixed gas of propane gas and oxygen gas in an equivalent amount is blown from the burner 3 and ignited at the same time. After confirming that the temperature inside the furnace has reached a controlled state of about 1600 ° C. with the temperature sensor 7, when incinerated ash is input from the ash input port 5, since the flame blowing speed is slow, ash scattering is small, and , Because high temperature is easily obtained, the ash melts quickly,
The melt 14 becomes a paste-like liquid and drops into the water 15 from the discharge port 13 and is granulated. However, if the melt 14 is taken out into the air without being submerged in the water and is decooled, it becomes a lump. Further, it can be made into a fibrous shape by stretching it, and can be effectively used as a concrete aggregate or a reinforcing material.

In the patent, when the crucible 4 is used for a long period of time and needs to be replaced, the melting furnace is cooled and then the furnace main body 1 is opened with the lid 2 opened to about 180 degrees. If the crucible protruding rod 6 is hydraulically driven or the crucible 4 is pushed by a manual screw rotation or the like after rotating the projection 17 on the side surface of the crucible 17 toward the downward direction, the action of the fluidized sand 11 is also exerted. In addition, the crucible 4 can be easily taken out, and the replacement can be performed very easily.

Further, the ash melting apparatus in the patent can be fixed by rotating around the protrusion 17 of the furnace body 1, the inclination of the furnace body 1 can be freely set, and the melt 14 A cylindrical anti-sticking material 19 having the same composition as the crucible is provided on the surface in order to adjust the outflow rate and to prevent the melt from adhering to the wall surface 16 of the discharge port 13 and solidifying and clogging. Is described as desirable.

According to the method of the patent, a heat-resistant graphite carbon silicon crucible having a carbon content of 30 to 55% and SiC of 30 to 50%, which is commercially available, for example, from Japan Crucible Co., Ltd., is used as the crucible 4. However, if the crucible 4 is continuously used for a long time at a high temperature of about 1600 to 1700 ° C. which is necessary for melting ash, the crucible 4 is extremely worn and can withstand only a few weeks to a few months. To
For repairs, the operation of the melting furnace is often stopped, or the operation is performed without noticing that the bottom of the melting furnace is missing, and in extreme cases, the heat-resistant layer inside the furnace is destroyed and cannot be used. Due to the decrease in the temperature near the discharge port 13, the ash melt may be cooled and solidified and clogged, which may cause a large problem such that the melting furnace cannot be used. Further, the heat insulation of the furnace wall is insufficient and the thermal efficiency may be low. Is not very good, so the fuel consumption is high, and the method of pushing out the crucible with the stick 6 from one side is adopted for exchanging the crucible, but in some cases it cannot be easily pushed out and cooling when exchanging the crucible is required. There was a problem such as taking time.

[0012]

In view of the above, the present invention has been made.
Even when used for a long time at a high temperature of 1600 to 1700 ° C or higher,
Dramatically improved durability and discharge port 1
Since the temperature around 3 is low, the ash melt is cooled and solidified and clogged, and the problem that the melting furnace cannot be used is improved, and the heat insulation of the furnace wall is improved to improve thermal efficiency and improve fuel efficiency. The main issues are lowering the crucible and making it easier and more efficient to replace the crucible.

[0013]

In the present invention, in order to solve the above-mentioned problems, a crucible having a three-layer structure, which consumes significantly less than before, is used for the crucible, and the discharge port 1
In order to prevent the temperature drop around 3, the auxiliary burner is used, the four-layer furnace wall is adopted to improve the heat insulation and the durability, and the lids are provided on both the left and right sides to form the crucible. Measures such as lowering the cost for taking out and improving work efficiency by shortening the cooling time when replacing the crucible were adopted.

[0014]

FIG. 2 shows an embodiment of the present invention, the main parts of which are a furnace body 1, a lid 2, a burner section 3, a crucible 4, an ash charging port 5, a temperature sensor 7 and the like. It is configured.

The furnace body 1 is preferably cylindrical, but
It may be in the shape of a polygonal column such as a square column, and the wall has a first heat-resistant layer 20 using castable from the innermost side, a first heat-insulating layer 21 such as asbestos, a second heat-resistant layer 22 such as castable, and asbestos. Second insulation layer 23, iron skin 12
The ash charging port 5 is provided on the upper surface of the furnace body 1, and the molten metal leak sensor 28 is provided in the backup sand 25 between the first crucible 24 and the second crucible 26. 24 is configured to detect an abnormality such as cracking, and there are two lids 2 on the right side and the left side, a discharge port 13 for discharging and discharging the melt 14 is provided on the lower left side, and an upper left side and a discharge side 13 are provided. A temperature sensor 7 is provided at the outlet 13, and a drop position 18 of the crucible 4 is provided so that the melt 14 does not contact the wall surface 16 of the discharge port 13.

The crucible 4 is, for example, the first crucible 2 from the inside.
4. The structure of at least three layers of the backup sand 25 and the second crucible 26, and the first crucible 24 is durable even at a high temperature of about 1700 to 2400 ° C. such as aluminum titanate type, alumina type, zirconia type, magnesia type, etc. The backup sand 25 uses a magnesia cement heat-resistant type, and the second crucible 26 has a carbon content of 30 to 30 made by Nippon Crucible Co. 55%, SiC 30-50%
Although a graphite charcoal siliceous crucible of a certain degree is used, at least by adopting this three-layer structure, the thermal conductivity of the conventional graphite charcoal siliceous crucible is extremely good, so that cracks due to thermal shock do not occur. Taking advantage of its advantages, the ultra-high temperature endurance type first crucible 24 is used as the contact point with the innermost layer of molten ash, and the heat resistant and highly durable backup sand 25 is used on the outside to make it extremely Good high-temperature long-term durability can be obtained, the number of times the crucible needs to be replaced, which has been frequently required in the past, can be significantly reduced, and if the crucible 4 has three or more layers, it is of course even better.

The lids 2 are provided at two places on the left and right, and like the furnace body 1, from the inside, a first heat-resistant layer 20 using castable, a first heat-insulating layer 21 such as asbestos, and a second heat-resistant using castable. Layer 22, a second insulating layer 23 such as asbestos,
It consists of five layers of iron skin 12, a burner 3 on the left lid 2.
Is provided slightly downward toward the opening of the crucible 4, and the flame of the auxiliary burner 27 is provided below the outlet 13 for the purpose of preventing solidification of molten ash due to cooling in the vicinity of the outlet 13. Aim at the vicinity of, and the left and right lids 2,
The hinges on the side surfaces allow easy opening and closing, and they are fixed to the furnace body 1 in an airtight manner so that they can be opened and closed with screws or the like, as shown in FIG.

The burner 3 used in the present invention is preferably a system in which petroleum gas such as propane gas and butane gas is used as a fuel, and is completely combusted with a relatively small amount of oxygen gas near the equivalent or air. The generated waste gas is relatively clean, and since it can be blown from the burner 3 at a relatively low pressure, the amount of ash scattered is small, and therefore the amount of ash contained in the exhaust gas can be reduced.
Further, since the ash is added to the vicinity of the highest temperature of the flame from the burner 3 toward the center of the crucible 4, melting is started immediately after the ash is added. Further, as described above, since the ratio of the rational furnace is very high, the thermal efficiency is very good, so that it is possible to use fossil fuels such as kerosene and city gas containing natural gas, which is inexpensive.

To operate the melting furnace shown in FIG. 2 in the present invention, for example, in the state shown in FIG. 2, a mixed gas of propane gas and oxygen gas in the vicinity of the equivalent is blown from the burner 3 and ignited at the same time, and the temperature sensor 7 The furnace temperature is 160
After confirming that it was in the control state of 0 to 1650 ℃,
When the incinerated ash is charged from the ash charging port 5, the ash is less scattered due to the slower blowing speed of the flame, and the high temperature is easily obtained, so that the ash is rapidly melted and the melt 14 becomes a liquid. From the discharge port 13, it falls into the water 15 and is granulated, but if it is taken out into the air without being submerged in the water and is decooled, it becomes a lump, and if it is stretched, it becomes a fibrous form. It can also be effectively used as a concrete or asphalt aggregate or reinforcing material.

[0020]

The ash melting apparatus of the present invention has the following effects due to the above-mentioned configuration. (1) The crucible has a three-layer structure consisting of a first crucible, a backup sand, and a second crucible from the inside.
Use a super high temperature endurance type that is durable even at high temperatures up to about 2400 ° C or higher.
A magnesia cement heat-resistant type is used, and the second graphite crucible uses the graphite carbon siliceous crucible that was used in the past.By adopting this three-layer structure, the conventional graphite carbon silica is used. Since the thermal conductivity of the quality crucible is good, the advantages that cracks due to thermal shock do not occur to the maximum are used, and the super high temperature durability type first crucible is used for the contact with the molten ash of the innermost layer. By adopting a backup sand with high heat resistance and heat insulation,
Very good high-temperature long-term durability can be obtained, and the number of times of crucible replacement, which has been frequently required in the past, can be significantly reduced. (2) By using the auxiliary burner 27 near the discharge port 13, it is possible to reliably prevent clogging of the discharge port 13 due to molten ash, which has been a serious problem in the past. (3) Since the lids 2 are provided on both the left and right sides, it is possible to perform the replacement work of the consumed crucible more easily than before, and to shorten the crucible replacement work because the furnace can be cooled more quickly when the crucible is replaced. It can be done in a short time, and has the effect of facilitating the cleaning work inside.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a conventional method.

FIG. 2 is a side sectional view showing an embodiment according to the present invention.

[Explanation of symbols]

1 furnace body 2 lid 3
Burner section 4 Crucible 5 Ash input port 6
Crucible protruding rod 7 Temperature sensor 8 First heat-resistant layer 9
Second heat-resistant layer 10 Third heat-resistant layer 11 Fluid sand 1
2 Iron crust 13 Discharge port 14 Melt 1
5 Water 16 Wall 17 Protrusion 1
8 Drop position 19 Sticking prevention material 20 First heat-resistant layer 2
1 1st heat insulation layer 22 2nd heat resistance layer 23 2nd heat insulation layer 2
4 First crucible 25 Backup sand 26 Second crucible 2
7 Auxiliary burner 28 Hot water leak sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3K061 NB03 NB27 NB28                 4K046 BA10 CB06 CB16 CD07 CE01                       CE05                 4K051 AA03 AB03 BA01

Claims (9)

[Claims] 1. A furnace comprising a furnace body 1 having a discharge port 13 and an ash charging port 5 and a lid 2 provided with a burner 3,
The innermost layer of the furnace body has a replaceable multi-layered crucible, the ash is melted with the opening of the crucible toward the lid side with the burner, and the melt 14 is discharged from the discharge port 13 by the action of gravity. An apparatus for melting ash characterized by: 2. The apparatus for melting ash according to claim 1, wherein a crucible having a three-layer structure of a first crucible 24, a backup sand 25, and a second crucible 26 is used as the crucible. 3. The first crucible 24 is made of, for example, aluminum titanate, alumina, zirconia, magnesia, or the like.
3. An apparatus for melting ash according to claim 2, wherein an ultrahigh temperature endurance type having a high temperature durability of about 700 to 2400 [deg.] C. or higher is used, and a graphite charcoal siliceous crucible is used for the second crucible 26. . 4. The ash melting apparatus according to claim 1, wherein the burner 3 is directed obliquely downward and a burner flame is blown toward the lower bottom of the crucible. 5. The ash melting apparatus according to claim 1, wherein an auxiliary burner 27 is provided near the discharge port 13. 6. The ash melting apparatus according to claim 1, wherein two lids 2 are provided on both the left and right sides. 7. The ash melting apparatus according to claim 1, wherein an ash charging port 5 is provided on the furnace body 1. 8. The molten metal leak sensor 28 is provided in the backup sand 25 between the first crucible 24 and the second crucible 26, and the molten metal leak sensor 28 is provided. Ash melting equipment. 9. A lid 2 and a furnace body 1 in which a first heat-resistant layer 2 is provided.
0, first heat insulating layer 21, second heat resistant layer 22, second heat insulating layer 2
3. The ash melting apparatus according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the ash melting apparatus is composed of five layers of 3, and an iron skin 12.