KR20180137681A - Melt discharger having nitrogen cooling structure - Google Patents

Abstract

The present invention relates to a melting furnace molten metal discharge device having a nitrogen cooling structure to easily discharge molten metal of a melting furnace, which comprises a heating device by an induction coil and a cooling device using a nitrogen gas nozzle. The molten metal discharge device is used to easily discharge molten metal of the melting furnace or stop the discharge through cooling and heating methods. Therefore, molten metal of a melting furnace of harmful waste can be easily and intermittently discharged.

Description

[0001] MELT DISCHARGER HAVING NITROGEN COOLING STRUCTURE WITH NITROGEN COOLING STRUCTURE [0002]

The present invention relates to an apparatus for easily discharging a molten metal in a melting furnace such as a ceramic melting furnace, a plasma arc melting furnace and an induction heating low-temperature melting furnace.

More stable handling, storage and management of hazardous wastes, especially radioactive waste from nuclear power generation, is a very important issue. Various techniques such as compression, incineration, and cement solidification have been applied as methods for treating such hazardous wastes. However, each technique has a problem of low cost and high possibility of secondary damage such as leachate. Among them, some hazardous wastes are treated and stored in some countries, and the harmful waste is burned by using induction heating type low temperature melting furnace, and the heavy metals are melted and made into a glass solid with glass to prevent it from leaching into the surrounding environment A melting furnace vitrification technology has been developed.

  Conventionally used melting furnaces are mostly based on top discharge. The molten metal discharge method includes a tilting method in which the melting furnace is tilted and discharged from the upper portion and a lower discharge method in which the melting furnace is fixed and the lower or side is discharged.

The upper discharge method can be used in a general workplace instead of a waste melting furnace by opening and discharging the lid of the melting furnace. However, the problem of radioactive waste disposal, hazardous waste disposal and sludge disposal is to observe the exhaust gas treatment process And it is mainly used for the lower discharge method of the melting furnace. To ensure safe operation.

However, in the conventional lower discharge method, the cylinder gate method and the mechanical discharge method are generally used. In the case of the cylinder gate method, since the high temperature cooling water flows in the gate plate jacket, the glass temperature is lowered, , Mechanical discharge has a problem that a metal valve immersed in molten metal is corroded and a melt is fixed to a valve movement guide. In addition, since the conventional outlet has a large diameter and a high induction heating output, it is necessary to completely discharge the molten metal in the melting furnace at one time, and there is a problem that partial discharge and intermittent discharge are difficult.

Korean Registered Patent No. 10-1457368 (Announcement of Mar. 11, 2014) Korean Patent No. 10-2005-0000922 (published on Jan. 15, 2005)

An object of the present invention is to provide a molten metal discharging device and a molten metal discharging device capable of discharging intermittent molten metal by melting and solidifying the molten metal by the cooling structure of the molten metal molten metal discharging device and thereby discharging the molten metal of the hazardous waste easily and safely In order to solve the problem.

It is an object of the present invention to provide a molten metal discharging apparatus for discharging a molten metal in the melting furnace to the outside of a melting furnace at least at a part of a discharging device body part, a molten metal discharging block located at least a part of the body part, A nitrogen gas nozzle unit configured to supply nitrogen gas supplied from the outside of the molten metal discharging device to the inside of the molten metal discharging path; a molten metal discharge nozzle located in the outer side of the molten metal discharging block, A molten metal discharge device having a nitrogen cooling structure that facilitates opening and closing of a molten metal discharge path including an induction coil for heating. .

 At least a part of the lower portion of the molten metal discharge path may have a tapered shape so that the horizontal cross section of the molten metal discharge path becomes larger as it goes downward.

At least a portion of the induction coil may be located within the discharge device body.

And an induction coil cooling pipe for cooling the induction coil.

The nitrogen gas nozzle unit may include two or more nitrogen gas nozzles and a nitrogen supply header for distributing nitrogen gas to the nitrogen gas nozzles.

At least a portion of the top of the molten metal discharge block may be positioned to protrude into the bottom of the melting furnace.

The protruding portion of the upper portion of the molten metal discharge block may include a tapered shape such that the sectional area increases from the upper portion to the lower portion.

And a molten metal discharge control unit for controlling power supply of the induction coil and gas supply of the nitrogen gas nozzle unit.

In the present invention, by applying the nitrogen gas cooling structure to the molten metal discharging device, it is possible to open and close the molten metal by the method of solidifying or melting the molten metal without using a separate molten metal discharge path opening and closing device, The treatment operation time can be greatly increased and the mechanical device for opening and closing the molten metal discharge path can be omitted, which is advantageous for maintenance, and an excellent economic effect can be obtained.

1 is a vertical sectional view of a molten metal discharging apparatus according to an embodiment of the present invention.
2 is a partial vertical cross-sectional view of a molten metal discharge apparatus according to an embodiment of the present invention.
3 is a cross-sectional view of a melting furnace including a molten metal discharge apparatus according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the drawings.

Plasma ceramic melting furnaces, plasma low temperature melting furnaces, plasma arc melting furnaces, induction heating low temperature melting furnaces, induction heating high temperature melting furnaces, electrode heating ceramic melting furnaces, and electric melting furnaces are examples of facilities for melting hazardous wastes, particularly radioactive wastes, into vitrification or sludge.

3 is a cross-sectional view of a melting furnace according to an embodiment of the present invention. (The molten metal discharging device 100 of the present invention) is located at the bottom or the bottom of the melting furnace. Generally, in a facility where molten waste is melted and sludgeized, harmful waste is put into the upper part of the melting furnace, and the molten metal is placed in the lower part of the melting furnace by gravity. Therefore, most of the molten metal discharging apparatus using the lower discharge method is located in the lower portion of the melting furnace, and is sometimes formed at the lower side of the side wall. The bottom portion of the melting furnace may be a flat shape as shown in the drawing, and a sloped shape may be used to smooth the discharge of the molten metal.

FIG. 1 is a vertical sectional view of a device for discharging a molten metal according to an embodiment of the present invention, and FIG. 2 is a partial vertical sectional view. The molten metal discharging device 100 according to the present invention has a molten metal discharging path and the molten metal discharging path includes a molten metal outlet discharging path inlet portion 110 and a molten metal discharging path discharging portion 120 as shown in the figure. In general, the molten metal in the melting furnace is discharged by gravity through the molten metal discharge path to the outside of the melting furnace.

The apparatus for discharging molten metal (100) according to the present invention includes a molten metal discharge block (130) formed with a molten metal discharge path. The molten metal discharge block 130 is preferably formed of a metal so as to facilitate heat transfer and withstand high temperatures, and it is more preferable to use inconel. The molten metal discharging block may include at least a part of the discharging device body 160. The discharging device body 160 may have a hollow interior and include a nitrogen supply pipe 141 and an induction coil 153 Mold < / RTI > The discharge device body 160 is preferably formed of a refractory material for facilitating heat dissipation from the outside.

The discharge device body 160 may be formed in a tapered shape. In order to facilitate maintenance, the discharge device body 160 is formed in a tapered shape outside the cylindrical body. When assembled to the bottom plate of the melting furnace, So as to have a convenient structure which is easy to remove downward. Most of the material of the discharging device is made of metal and caster, and the total weight of the discharging device is considerable. Therefore, it is preferable that the cylindrical outer shape of the discharging device is tapered.

The apparatus for discharging molten metal (100) in the present invention includes an induction coil part (153) which is a heating device for keeping the molten metal in a liquid state for smooth discharge of molten metal. The induction coil is located on the outer periphery of the tubular discharge path of the molten metal and is coil-shaped. When power is supplied to the induction coil 153, the metal located inside the coil is heated by the electromagnetic induction method. When the power is supplied to the induction coil 153, the molten metal discharging path of the metallic material is heated, and the molten metal discharging path maintains a high temperature inside the molten metal discharging path, so that the molten metal in the melting furnace maintains a liquid state and can be smoothly discharged to the outside of the melting furnace. In order to smoothly discharge the molten metal, it is preferable that the lower portion of the molten metal discharge path has a tapered shape 170 and the horizontal cross section gradually increases as it goes downward. In the case of a tapered shape, the discharge resistance due to the inner wall tension of the molten metal discharge path is reduced. In order to prevent the residual molten metal from adhering to the lower part of the molten metal discharge port and to prevent the temperature of the molten metal discharging path from lowering, the thermal influence by the induction coil is designed in a taper shape close to the induction coil so that a constant temperature is maintained at the end of the discharge pipe. It is possible to prevent the fixture from adhering to the inclined surface.

Since the induction coil 153 is located adjacent to the high temperature molten metal, it can be easily deteriorated by the high temperature. In order to prevent this, the induction coil 153 may be located in a separate cooling coil for the induction coil. Inside the cooling tube, a cooling fluid (such as cooling water) for cooling the induction coil 153 is circulated. The induction coil further includes an induction coil and a cooling water inlet portion 151 and an induction coil and a cooling water outlet portion 153 so that the cooling fluid can be drawn from the outside.

3 is a cross-sectional view of a melting furnace 10 including a molten metal discharge apparatus according to an embodiment of the present invention. The upper end of the molten metal discharge block 130 has a tapered shape with an inclined surface 131 through which molten non-melted and non-melted non-metallic materials are prevented from entering the molten metal discharge path .

In the present invention, cooling nitrogen gas is used as a method for solidifying the molten metal in the molten metal discharging apparatus 100 to stop discharging. The nitrogen gas for cooling in the present invention means liquid nitrogen or a nitrogen gas at a low temperature equivalent thereto. Nitrogen has a boiling point of 196 ° C at 1 atmosphere and is extremely cold. When the cooling nitrogen is used to supply the molten metal to the outside of the tubular molten metal discharge path, the molten metal inside the molten metal discharge path is cooled and solidified. The molten metal discharge path is closed by the solidified molten metal, and the molten metal discharge is stopped.

A nitrogen gas nozzle 143 is formed in the center of the molten metal discharge block 130 toward the molten metal discharge path so as to uniformly supply the cooling nitrogen to the molten metal discharge path and cool it quickly. It is preferable that the nitrogen gas nozzle is supplied with the nitrogen gas distributed from the nitrogen supply header 142 and the nitrogen supply header 142 is formed with two or more nozzles. The plurality of nozzles may be formed uniformly or irregularly, and may be selected according to the size of the molten metal discharge path and the type of discharge material. A nitrogen supply pipe 141 for supplying nitrogen to the nitrogen supply header 142 is also included.

In order to maintain the solidified state of the molten metal in the molten metal discharge path, the supply of nitrogen gas for cooling can be basically maintained. However, after the solidification, the cooling fluid flowing in the induction coil part 153 is used to cool the molten metal, It is possible to maintain the state. At this time, the power supply to the induction coil is cut off.

In addition, it is preferable to automate the heating and cooling so that the discharge of the molten metal from the molten metal is facilitated through the molten metal discharging path, and the molten metal is discharged intermittently smoothly. To this end, the molten metal discharging device 100 may include a sensor unit such as a temperature sensor, and may include a molten metal discharge control unit for controlling the supply of the induction coil and the nitrogen for cooling according to the cooling and heating conditions.

A method for discharging a molten metal in a molten metal discharging device having a cooling structure to achieve the object of the present invention is as follows.

In the melting furnace, the glass components for the waste and the molten metal may be melted together, and if the molten metal exceeds a certain volume in the melting furnace, the discharge is required. If power is supplied to the induction coil included in the device for discharging the molten metal, the molten metal discharge path is heated by the induction current. This step is the exhaust path heating step. The solidified waste in the molten metal discharge path is heated by an induction current, and when heated above the melting temperature, it is melted into a liquid phase and discharged to the bottom by gravity. The molten metal in the melting furnace is discharged to the outside through the molten metal discharging device 100 by the opened molten metal discharging pass, and this step is the discharging step. In order to stop discharging the molten metal, the molten metal in the molten metal discharge path is solidified through cooling. This step is the discharge stop phase. Cooling can be accelerated by using nitrogen for cooling to cool the molten metal in the cooling step. When the molten metal in the molten metal discharge path is solidified through the cooling step, the cooling water can be supplied to the induction coil part 153 to maintain the low temperature state. This step is the discharge stop maintenance step.

By repeating the heating step, the discharging step and the discharging stopping step as described above, the discharging and stopping of the molten metal can be repeatedly performed, thereby enabling the discharging of the molten metal intermittently.

The molten metal of the hazardous waste can be easily discharged by the molten metal discharging device and the molten metal discharging method as described above, and the intermittent discharging is facilitated, and the waste treating time of the melting furnace can be greatly increased, which is very efficient and economical.

The above-described embodiments are illustrative of the present invention, and the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (8)

As a molten metal discharging device for a melting furnace,
A discharge device body;
A molten metal discharge block located at least in a part of the body part;
A molten metal discharge path formed in at least a part of the molten metal discharge block so as to discharge molten metal in the molten metal to the outside of the molten metal;
A nitrogen gas nozzle unit configured to supply nitrogen gas supplied from the outside of the molten metal discharge device into the molten metal discharge path;
An induction coil positioned at an outer side of the molten metal discharge block for heating the molten metal in the molten metal discharge path;
Wherein the molten metal discharging path has a nitrogen cooling structure that facilitates opening and closing of the molten metal discharging path. The method of claim 1,
Wherein at least a part of the lower portion of the molten metal discharge path has a tapered shape so that the horizontal cross section of the molten metal discharge path increases as the molten metal discharge path descends to the lower end portion. The method of claim 1,
Wherein at least a portion of the induction coil is located in the discharge device body. The method of claim 1,
Further comprising an induction coil cooling pipe for cooling the induction coil. The method of claim 1,
Wherein the nitrogen gas nozzle unit comprises two or more nitrogen gas nozzles and a nitrogen supply header for distributing nitrogen gas to the nitrogen gas nozzles. The method of claim 1,
And at least a part of the upper portion of the molten metal discharge block is positioned so as to protrude to a bottom portion of the melting furnace. The method of claim 6,
Wherein the protruding portion of the upper portion of the molten metal discharge block has a tapered shape so as to have a larger sectional area from the upper portion to the lower portion. The method of claim 1,
Further comprising a molten metal discharge control section for controlling power supply of the induction coil and gas supply of the nitrogen gas nozzle section.

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