JPH068975Y2 - Melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a melting furnace, and more particularly to improvement of an off-gas discharge pipe of the melting furnace.

“Prior Art” Generally, in a melting furnace, a material to be melted is placed between electrodes facing each other in a melting tank, and it is used that the material to be melted or the melted material has conductivity. Then, a current is passed between the electrodes to generate resistance heat, thereby promoting the dissolution of the material to be dissolved.

An example of the substance to be melted is glass used for solidifying high-level radioactive waste (waste liquid). An example of the solidification processing plant will be described with reference to FIG. 2. In the melting furnace main body 3 housed in the airtight chamber 2 of the cell 1, waste such as radioactive waste liquid and a glass material to be dissolved are Is sent to dissolve, and these molten mixtures are filled in a container prepared elsewhere to be solidified by cooling,
In addition, a series of solidification treatments such as air pollution monitoring for leak inspection are implemented.

Then, the off gas generated in the melting furnace main body when the waste and the substance to be melted are charged is sucked and discharged by the off gas discharge pipe 4 and the off gas suction and discharge system 5 using a blower or the like. ing.

By the way, in such a melting furnace, the melting furnace main body 3
When off-gas is discharged from the off-gas exhaust pipe 4, pressure loss or the like occurs, so that particles or the like in the mist mixed in the off-gas easily adhere to the inner surface of the off-gas exhaust pipe 4 to solidify, and the solidified product There is a problem in that the resistance of the flow path increases as the amount of P increases.

Therefore, conventionally, the vicinity of the opening of the offgas discharge pipe 4 is
As shown in FIG. 3, it is considered that a double pipe structure including an outer pipe 6 and an inner pipe 7 is formed, and an air curtain is formed along the inner surface of the inner pipe 7 to prevent adhesion. The air curtain supplies pressurized air from a nozzle 10 to an outer pipe 6 from a compressed air supply system 8 outside the cell 1 through a cell penetrating portion 9 to connect an outer pipe 6 and an inner pipe 7. Along the inner surface of the inner pipe 7 from the annular slit 11 of the inner pipe 7 via the annular gap K of
In order to form the slits 11, the inner pipe 7 has a divided structure, and the support plates are arranged at intervals of 90 degrees in the circumferential direction, for example. By attaching 12 by welding, connection in the length direction and setting of the slit width and the like are performed.

[Problems to be Solved by the Invention] However, in such a conventional melting furnace, when pressurized air is supplied from the nozzle 10 to the annular gap K, the pressurized air flows through the inner tube 7 to cause fluid resistance. Therefore, the flow rate increases on the side of the nozzle 10 and decreases on the side opposite to the nozzle 10, resulting in unevenness in the circumferential direction, and therefore a difference in the flow rate in the circumferential direction of the slit 11, resulting in There is a problem that the air curtain is not formed uniformly over the entire inner surface of the inner tube 7.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to average the flow velocity of pressurized air over the entire circumference in the annular gap of the offgas discharge pipe, and thus to reduce the air curtain. It is to provide a melting furnace that can be formed uniformly.

[Means for Solving the Problem] In order to achieve the above-mentioned object, the melting furnace of the present invention has an outer pipe having a nozzle for supplying pressurized air, in which an off gas is passed and an air curtain forming slit is provided. An inner pipe is provided, and an off-gas discharge pipe is provided on the outer surface of the inner pipe, the baffle plate being located in the pipe between the nozzle and the slit to narrow the annular gap between the outer pipe and the inner pipe. It is a feature.

[Operation] In the melting furnace of the present invention, since the annular space is narrowed between the nozzle and the slit by the baffle plate, the pressurized air supplied from the nozzle to the annular space passes through this narrow portion. In addition, the flow velocity is averaged in the circumferential direction. Therefore, the flow velocity of the jet flow from the slit thereafter is averaged over the entire circumference, and as a result, a uniform air curtain is formed over the entire circumference of the inner surface of the inner pipe.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same components as those in FIGS. 2 and 3 are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 20 is a baffle plate, and the baffle plate 20 is provided on the outer surface (outer surface) of the inner pipe 7 between the nozzle 10 and the slit 11 closest to the nozzle and the outer surface and the outer pipe 6. It is formed in an annular shape so as to narrow the annular gap K with the inner surface.

In the melting furnace configured as described above, when the pressurized air supplied from the nozzle 10 to the annular gap K passes through the portion narrowed by the baffle plate 20, its flow velocity is averaged in the circumferential direction. To be done. Therefore, the flow velocity of the jet flow from the slit 11 thereafter can be averaged over the entire circumference, and as a result, a uniform air curtain can be formed over the entire circumference of the inner surface of the inner pipe 7. .

[Advantage of Invention] As described above, in the melting furnace of the present invention, the annular space between the outer pipe and the inner pipe is located on the outer surface of the inner pipe and is located between the nozzle and the slit. Since the baffle plate is provided, the flow velocity of the pressurized air supplied from the nozzle to the annular space is averaged in the circumferential direction when passing through the portion narrowed by the baffle plate. Therefore, the flow velocity of the jet flow from the slit thereafter can be averaged over the entire circumference, and as a result, a uniform air curtain can be formed over the entire circumference of the inner surface of the inner pipe. Play.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the melting furnace of the present invention, FIG. 2 is a sectional view showing the concept of a solidification treatment plant incorporating the melting furnace, and FIG. 3 is a chain line III in FIG. It is an expanded sectional view of a part. 4 ... Off-gas discharge pipe, 6 ... Outer pipe, 7 ... Inner pipe, K ... Annular space, 10 ... Nozzle, 11 ... Slit, 20 ... Baffle plate.

Claims (1)

[Scope of utility model registration request] 1. An inner pipe having a slit for forming an air curtain and an off gas passing through the outer pipe having a nozzle for supplying pressurized air, the nozzle and the slit being provided on the outer surface of the inner pipe. And an off-gas discharge pipe provided with a baffle plate located between the outer pipe and the inner pipe to narrow an annular gap between the outer pipe and the inner pipe.