JP3732961B2 - Cooling device for waste after melting treatment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a cooling apparatus for a waste body after melting treatment, and in particular, general waste containing various inorganic substances, metals and organic substances, sewage sludge, municipal waste and incineration ash thereof, and further, a low level of radioactive material. The present invention relates to a cooling device used when a waste is manufactured by cooling and solidifying a melt after heat treatment of a waste or the like to a melting point or higher by means of plasma arc, induction heating, combustion heating or the like.
[0002]
[Prior art]
Incineration ash discharged from municipal waste and sewage sludge incineration plants has been disposed of in landfills at the final landfill site. In addition, low-level radioactive waste generated from nuclear power plants, for example, building wastes such as concrete and steel frames surrounding buildings, and inorganic materials such as piping materials, as well as combustible materials such as wiring materials and clothing, Flame retardants are mixed as incinerated ash and stored and stored in drums. However, in recent years, demands for technologies for reducing the volume of waste as much as possible have increased due to the relationship between the capacity of the disposal site and the storage location, the deadline, and the like.
[0003]
In order to reduce the apparent volume of the waste, the melt solidification method in which the waste is heated to the melting point or higher and then cooled and solidified is the most common method, and so far, plasma arc, induction heating, Various processes have been proposed using a melting furnace equipped with a heating means such as combustion heating, and some have been put into practical use.
[0004]
By the way, in the process using the melting furnace proposed above, it is necessary to cool and solidify the molten waste. As this cooling and solidifying means, there is one proposed in Japanese Patent Laid-Open No. 9-90096, although the target waste is a low-level radioactive miscellaneous solid waste.
[0005]
The cooling and solidification means proposed in the above-mentioned publications include (1) a melt that has been known so far, dropped into a water tank to form a glassy granular material, and (2) water-cooling the melt into a solidification chamber. The method of cooling and solidifying with a mold or (3) cooling the molten material together with the crucible in the cooling chamber is the method of (1), where water and cooling medium are contaminated with radioactivity, etc., and secondary disposal due to contamination. In the method of (2), the solidified material taken out from the mold is broken or scattered during handling, and in the method of (3), it is necessary to use a thick crucible to withstand the melting process. In order to solve these problems, etc., the melting volume discharged from the melting furnace is changed into a thick-walled refractory structure holding container. Filled in a reduced-pressure atmosphere into a thin steel receiver held in However, by cooling, bubbles in the melt due to dissolved gas and entrained gas in the melt are released, and the melt is separated into a metal layer and a slag layer due to the difference in specific gravity. Cooling and solidifying means such as cooling inside is adopted.
[0006]
[Problems to be solved by the invention]
However, the cooling and solidification means proposed in the above publication can suppress the generation of secondary waste such as cooling water and exhaust gas, and can increase the volume reduction ratio because bubbles in the melt are released. Moreover, since the solidified shape of the melt can be made to have a size and shape close to the shape of the final waste body (drum can), it is possible to increase the waste housing efficiency at the disposal site and storage place. However, there are concerns about the following problems. That is,
(1) Since the melted material is filled into the thin-walled steel receiver held in the thick-walled fireproof holding container, there is a concern that the thin-walled steel receiver may be deformed or melted. If the material is greatly deformed or melted, a serious accident may occur in which the melt flows out of the holding container.
(2) Bubbles such as dissolved gas and entrained gas in the melt are released by natural cooling, and the melt is separated into a metal layer and a slag layer due to the difference in specific gravity. Cooling room incidental facilities such as a room volume and a cooling fan become large and cost increases.
[0007]
The present invention has been made in view of the above-described problems, and its purpose is not to deform or damage the thin-walled steel receiver in the processing step of the waste melt discharged from the melting furnace. Disposal after melting processing that can cool the melt filled in the thin-walled steel receiver safely and quickly, and can reduce the space for the cooling chamber and the cost of the cooling room incidental equipment such as a cooling fan. A body cooling device is provided.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a cooling apparatus for a waste body after melting treatment according to the present invention accommodates a heat-melted waste melt in a thin-walled steel receiver and cools and solidifies it as a waste body together with the receiver. A thin-walled steel receiver for storing the heated and melted waste melt, and a holding container for receiving the receiver in close contact with the bottom and the periphery of the receiver And the holding container is made of a material having a thermal conductivity of 5.8 W / m · K or more.
[0009]
In the above configuration, since the thin-walled steel receiver is housed in the holding container with its bottom and periphery in close contact, the holding container is made of a material having a thermal conductivity of 5.8 W / m · K or more. Therefore, even if the waste melt heated and melted in the melting furnace is injected into and accommodated in the thin steel receiver, the heat of the melt is quickly transferred from the thin steel receiver wall to the holding container wall. The time during which the receiver made of thin steel is heated and exposed to a high temperature is short, and the melt can be quickly cooled and solidified as well as preventing deformation and melting of the receiver. As a result, the space for the cooling chamber can be reduced, and a large-scale cooling facility is not required, so that cost reduction can be expected. In order to obtain such an effect more effectively, that is, to obtain a rapid heat removal effect, the holding container is preferably made of a material having a thermal conductivity of 11.6 W / m · K or more.
[0010]
In the present invention, although not particularly limited, stainless steel materials (thermal conductivity: 16 W / m · K) and carbon steel materials (thermal conductivity: 43 W / m · K) are used as materials for forming the holding container. A copper material (thermal conductivity: 386 W / m · K) and an aluminum material (thermal conductivity: 164 W / m · K) can be used alone or in a laminate of two or more. By using such a material for the holding container, the above-mentioned effects can be enjoyed more effectively and economically. In particular, in the case of disposal of radioactive material waste melt, it is also possible to use the material by laminating a lead material or a resin material, which can be expected to improve the radiation shielding effect in the cooling chamber.
[0011]
In the present invention, the holding container may include a cooling medium flow path. By providing the cooling medium flow path in this way, the cooling effect is further increased, and the molten material that is poured into and accommodated in the thin-walled steel receiver is not only prevented from being deformed and melted. It can be cooled efficiently.
[0012]
Moreover, in the said invention, a holding | maintenance container may have a ditch | groove of a vertical direction at least in the part closely_contact | adhered to the circumference | surroundings of a receiver. By providing this concave groove, it is possible to absorb the expansion of the receptacle that occurs when the melt is poured into and accommodated in the thin steel receptacle.
[0013]
In the present invention, the holding container may be divided into two or three in the vertical direction, or divided into a bottom portion and a portion that is in close contact with the periphery of the receiver, and is in close contact with the periphery of the receiver. The part to be performed may be divided into two or three in the vertical direction. By adopting such a divided configuration, the bottom of the receiver and the surrounding holding container can be more securely adhered, the cooling effect can be increased, and the thin-walled steel receiver can be prevented from being deformed or damaged. Of course, it is possible to efficiently cool the melt poured and contained in the thin-walled steel receiver. Further, it becomes easy to take out the waste body after cooling and solidification.
[0014]
In the present invention, a cooling medium spraying device that sprays the cooling medium toward the outer wall of the holding container may be provided on the outer peripheral side of the holding container. By providing such a cooling medium spraying device, it is possible to increase the heat removal effect from the outer peripheral side of the holding container, increase the cooling effect, and to prevent deformation and erosion of the thin-walled steel receiver, The melt poured and contained in the thin-walled steel receiver can be efficiently cooled.
[0015]
The cooling device according to the present invention is provided on the discharge side of a waste melting furnace in which the waste melt dissolves one or more of inorganic waste, sewage sludge, waste incineration ash, and radioactive waste, It is used to contain and cool the melt discharged from the furnace.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of a cooling device for a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view.
[0017]
The cooling device 1 includes a thin-walled steel receiver 2 and a holding container 3, and the thin-walled steel receiver 2 is a container having a bottom portion 4 and a cylindrical portion 5, and includes a bottom portion 4 and a cylindrical portion 5. The wall thickness is about 10mm.
[0018]
The holding container 3 is a stainless steel container having a cylindrical part 6 and a bottom part 7 having an inner diameter substantially equal to the outer diameter of the receiver 2 and having a wall thickness of about 100 mm and can be divided into left and right container bodies 8 and 9. In addition, flanges 10 and 11 are provided on the outer side of the divided end surface of the cylindrical portion 6, and the bolts and nuts 12 are attached to the flanges 10 and 11 so as to be integrated. In this example, the case where the holding container 3 is divided into two parts is taken as an example, but it may be divided into three parts. The division into four is not preferable because it takes time for the work and operation for integration. Moreover, in order to integrate, the example by the flanges 10 and 11 and the bolts and nuts 12 was taken, but if the adhesion with the receiver 2 described later is obtained together with the integration, the configuration is not particularly limited. For example, it may be driven back and forth by a cylinder provided on the back surface of the container bodies 8 and 9, or may be configured to be simply tightened with a metal band. The holding container 3 may be a bottomed cylindrical body, but it is necessary to consider so as to increase the contact portion with the thin-walled steel receiver 2.
[0019]
The cooling device 1 accommodates the thin steel receiver 2 in the holding container 3 so as to be sandwiched between the left and right container bodies 8 and 9 and then bolts and nuts to the flanges 10 and 11 of the left and right container bodies 8 and 9. Constructed by installing 12 and tightening the nut. Although not shown, the cooling device 1 configured in this way is set in the hot water chamber of the melting furnace, injects and stores the waste melt 13, and is then transferred to the cooling chamber where it is made of thin-walled steel. The waste melt 13 in the container 2 is cooled and solidified. Then, after the waste melt 13 is cooled and solidified, the bolts and nuts 12 are loosened and separated into the left and right container bodies 8 and 9, and the thin steel receptacle 2 and the waste solidified by cooling in the receptacle 2 are formed. Remove the waste. After the take-out, the holding container 3 has a thin-walled steel receiver 2 set therein and is repeatedly used as the cooling device 1.
[0020]
The cooling device 1 is used as described above. Since the holding container 3 is made of stainless steel having a wall thickness of about 100 mm, it is excellent in thermal conductivity and has a large heat capacity. The waste melt 13 accommodated in the receiver 2 can be quickly cooled and solidified without causing the receiver 2 to be deformed or melted. In addition, since the cooling and solidification can be performed quickly, a large-scale forced cooling facility is not required, the space for the cooling chamber can be reduced, and a cost reduction can be expected because a large-scale cooling facility is unnecessary.
[0021]
FIG. 2 is an explanatory view of another embodiment of the cooling device for a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view. The cooling device 14 of the example shown in this figure is configured by dividing the holding container 3 into a bottom portion 15 and a portion (cylindrical portion) 16 that is in close contact with the periphery of the receiver 2, and further the cylindrical portion 16 in the vertical direction. 1 is formed into cylindrical parts 17 and 18, and the bottom 15 and the cylindrical parts 17 and 18 and the cylindrical parts 17 and 18 are similar to the flanges and bolts and nuts shown in FIG. Except that the fastening means is provided, the configuration is the same as that of the cooling device 1 shown in FIG.
[0022]
Even the cooling device 14 configured as described above can be used in the same manner as the cooling device 1 shown in FIG. 1 and can obtain the effects shown in paragraph [0020].
[0023]
FIG. 3 is an explanatory view of another embodiment of the cooling device for the waste body after the melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view. The cooling device 19 of the example shown in this figure is provided with a cooling medium flow path 20 meandering from the top to the bottom on the outer peripheral surface of the cylindrical parts 17 and 18 of the holding container 3 shown in FIG. The same configuration as the cooling device shown in FIG. 2 except that the cooling medium supply port is provided in the lower portion and the cooling medium discharge port is provided in the upper portion and the cooling medium from the discharge port is re-cooled and circulated. belongs to. In this example, the cooling medium flow path 20 is provided only in the cylindrical parts 17 and 18, but it goes without saying that the cooling medium flow path 20 may also be provided in the bottom part 15.
[0024]
Even the cooling device 19 configured as described above can be used in the same manner as the cooling device 1 shown in FIG. 1 or the cooling device 14 shown in FIG. 2 and obtains the operational effects shown in paragraph [0020]. Can do. Further, in this example, although the cooling medium flow path 20 is provided, the cooling cost is slightly increased, but the cooling effect is increased by forced cooling, and the waste melt 13 accommodated in the thin-walled steel receiver 2 is The receiver 2 can be cooled and solidified more quickly without being deformed or melted.
[0025]
In order to obtain the cooling effect as described above, a cooling medium (gas) jetting device (nozzle) 21 is disposed around the outer periphery of the cylindrical portion 16 as shown by a two-dot chain line in FIG. May be. Thus, even if the ejection device 21 is arranged and the outer peripheral surface of the holding container 3 (the container bodies 8, 9 and the cylindrical portion 16) is forcibly cooled, the same effect as the paragraph [0024] can be obtained. it can. When the outer periphery of the holding container 3 is forcibly cooled by blowing a cooling gas in this way, heat radiating fins may be provided on the outer periphery of the holding container 3 in order to increase the heat dissipation effect.
[0026]
FIG. 4 is an explanatory view of another embodiment of the cooling device for the waste body after the melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view. The cooling device 22 of the example shown in this figure has a configuration in which four vertical grooves 23 are provided at substantially equal intervals on the inner peripheral surface of the cylindrical portions 17 and 18 of the holding container 3 shown in FIG. It has the same configuration as the cooling device 14 shown in FIG. In this example, an example in which the concave groove 23 is provided below the center of the cylindrical parts 17 and 18 is shown. However, the height of the concave groove 23 is accommodated in the thin-walled steel receiver 2. Needless to say, it may be provided up to the top of the waste melt 13. FIG. 1a shows a cross-sectional view of the groove 23 shown in FIG. 1b.
[0027]
Even the cooling device 22 configured as described above can be used in the same manner as the cooling device 1 shown in FIG. 1 or the cooling device 14 shown in FIG. 2 and obtains the operational effects shown in paragraph [0020]. Can do. Further, in this example, by providing the concave groove 23, it is possible to absorb the expansion of the receiver 2 that occurs when the waste melt 13 is injected and stored in the receiver 2 made of thin steel.
[0028]
【The invention's effect】
As described above, if it is a cooling device for a waste body after melting treatment according to the present invention, the receptacle made of thin-walled steel can be accommodated in the holding container with its bottom and surroundings closely attached, and the holding container is Since it is composed of a material having a thermal conductivity of 5.8 W / m · K or more (more preferably 11.6 W / m · K or more), the waste melt heated and melted in the waste melting furnace is received by the thin-walled steel. Even when injected and contained in a container, the heat of the melt can be transferred quickly from the thin-walled steel receiver wall to the holding container wall, reducing the time during which the thin-walled steel receiver is exposed to high temperatures. In addition to preventing deformation and erosion of the receiver, the stored waste melt can be quickly cooled and solidified. In addition, because of the above-described configuration, the space for the cooling chamber can be reduced, and a large-scale cooling facility is not required, so that cost reduction can be expected.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a cooling apparatus for a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view.
FIGS. 2A and 2B are explanatory views of another embodiment of a cooling apparatus for a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view.
FIGS. 3A and 3B are explanatory views of another embodiment of the cooling apparatus for a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view. FIGS.
FIGS. 4A and 4B are explanatory views of another embodiment of the apparatus for cooling a waste body after melting treatment according to the present invention, in which a is a cross-sectional view and b is a top view. FIGS.
[Explanation of symbols]
1: Cooling device 2: Receptor made of thin steel 3: Holding container 4: Bottom portion of the receiver 5: Cylindrical portion of the receiver 6: Cylindrical portion of the holding container 7: Bottom portion of the holding container 8, 9: Container body 10, 11: Flange
12: Bolts and nuts 13: Waste melt 14: Cooling device
15: Bottom of holding container 16: Cylindrical part of holding container
17, 18: Cylindrical part of holding container 19: Cooling device
20: Cooling medium flow path 21: Cooling medium ejection device 22: Cooling device
23: Groove

Claims (9)

A cooling device for storing a heat-melted waste melt in a thin-walled steel receiver and cooling and solidifying it as a waste body together with the receiver, the thin-wall steel for storing the heat-melted waste melt And a holding container for accommodating the receiving container in close contact with the bottom and the periphery of the receiving container, and the holding container is made of a material having a thermal conductivity of 5.8 W / m · K or more. An apparatus for cooling a waste body after melting treatment, characterized in that the apparatus is configured. The apparatus for cooling a waste body after melting treatment according to claim 1, wherein the holding container is made of a material having a thermal conductivity of 11.6 W / m · K or more. The material forming the holding container is one of a stainless steel material, a carbon steel material, a copper material, and an aluminum material, or a laminate material of two or more of these materials. Waste body cooling system. The apparatus for cooling a waste body after the melting treatment according to any one of claims 1 to 3, wherein the holding container includes a flow path for a cooling medium. The apparatus for cooling a waste body after melting treatment according to any one of claims 1 to 4, wherein the holding container has at least a longitudinal groove in a portion closely contacting the periphery of the receiver. The apparatus for cooling a waste body after melting treatment according to any one of claims 1 to 5, wherein the holding container is divided into two or three in the vertical direction. 6. The holding container according to claim 1, wherein the holding container is divided into a bottom portion and a portion that is in close contact with the periphery of the receiver, and a portion that is in close contact with the periphery of the receiver is divided into two or three in the vertical direction. Cooling device for waste after melting treatment. The apparatus for cooling a waste body after melting treatment according to any one of claims 1 to 7, further comprising a cooling medium spraying device that sprays a cooling medium toward an outer wall of the holding container on an outer peripheral side of the holding container. The melt according to any one of claims 1 to 8, wherein the waste melt is a melt discharged from a waste melting furnace that dissolves at least one of inorganic waste, sewage sludge, waste incineration ash, and radioactive waste. Cooling device for waste after processing.

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