JPS5828559B2 - RI waste incinerator exhaust gas treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an RI waste incinerator exhaust gas treatment device.

Due to the nature of incinerators for waste containing RI (radioactive substances), it is desirable to generate as little residue as possible after treatment, and discharge of RI outside the system must be almost completely prevented.

The conventional methods for treating RI waste incinerator exhaust gas can be roughly divided into three methods shown in FIGS. 1 and 2.

The system shown in FIG. 1 uses a high-temperature filter device whose furnace material is a packed bed of porous ceramics or asbestos to remove dust from exhaust gas.

That is, according to this, by passing the exhaust gas from the incinerator 1 through the high temperature filter device 2, unburned carbon, tar, etc. in the exhaust gas are collected by the furnace material, and these are incinerated on the surface of the material, Next, the exhaust gas discharged from the high-temperature filter device 2 is diluted and cooled through an air dilution device 3, and then released into the atmosphere through a purification filter device 4.

However, the porous ceramics used as the furnace material of the high-temperature filter device 2 is susceptible to heat and mechanical shock, and the asbestos layer is particularly vulnerable to mechanical shock, and it is difficult to form a uniform packed layer, resulting in poor dust removal performance. is not constant.

In addition, it has disadvantages such as the need to handle asbestos, which causes silicosis.

Furthermore, when the furnace materials are replaced when their performance has deteriorated, the furnace materials themselves generate new waste as pollutants, which greatly reduces the effectiveness of ash volume reduction.

The system shown in FIG. 2 uses an electrostatic precipitator to remove dust from exhaust gas.

That is, the exhaust gas from the incinerator 5 is first lowered to a predetermined temperature by a heat exchanger tube type cooling device 6, and then guided to an electrostatic precipitator 7, and the dust-removed exhaust gas is then passed through an air diluter 8 to be diluted. It is further discharged into the atmosphere through a purification filter device 9.

According to this, although it does not have the drawbacks of the one shown in Fig. 1, the electrostatic precipitator 7 is larger than other devices, so the area occupied by the entire processing device is very large, and the processing system is not completely airtight. Difficult to hold in place.

As described above, each of the conventional methods has its own drawbacks.

The present invention has been made to eliminate the drawbacks of the conventional device described above, and an embodiment thereof will be described below with reference to FIG.

10 is an incinerator, and 11 is a cooling device.

The cooling device 11 has a supply air heat transfer pipe 13 communicating with the outlet of the supply air fan 12, and the air flowing through the supply air heat transfer pipe 13 and the exhaust gas G1 sent through the exhaust gas pipe 14 of the incinerator 10. Heat exchange is performed between the

A valve 1 is interposed in the supply air heat transfer pipe 13.

15 is a primary filter device, and a cooling device 11 is connected to the primary filter device 15 through an exhaust gas introduction pipe 16.
A high temperature exhaust gas G2 of 400 to 600° C. is introduced.

Graphite is used as the furnace material 17 of the primary filter device 15.

Reference numeral 18 denotes an air dilution device, in which the exhaust gas G3 from which dust has been removed by the primary filter device 15 is mixed with the air sent from the fan 19 and diluted.

20 is a secondary filter device, which purifies the exhaust gas from the dilution device 18 by removing dust.

After exiting the secondary filter device 20, the exhaust gas is released into the atmosphere.

Reference numeral 21 denotes a bypass passage for the supply air heat transfer pipe 13, which is provided between the population side of the supply air heat transfer pipe 13 and the middle of the exhaust gas introduction pipe 16, and has a valve 2 at its inlet.
has.

According to the above, the high-temperature exhaust gas G2 exiting the cooling device 11 is subjected to dust removal in the primary filter device 15 whose furnace material 17 is graphite.

Graphite can withstand heat and mechanical shock well, and when replacing furnace materials due to performance deterioration, if used graphite is thrown into an incinerator, the graphite will be completely incinerated and only the collected dust will become ash. Remains in the hearth.

This eliminates the generation of new waste from the furnace material itself.

In addition, some unburned carbon, tar, etc. may adhere to the inner wall of the cooling device 11 or the wall of the supply air heat exchanger tube 13, but in that case, close the valve v1 to stop the air supply into the supply air heat exchanger tube 13. Then, the inside of the cooling device 11 is heated to 600 to 900° C. by the exhaust gas itself from the incinerator 10 (decoking operation).

This heating incinerates and removes the unburned carbon, tar, and the like.

During this time, the valve V2 of the bypass pipe 21 is opened, air is supplied into the exhaust gas introduction pipe 16 through the bypass pipe 21, mixed with high-temperature exhaust gas from the cooling device 11, and the temperature is set to 400 to 600°C. It is introduced into the filter device 15.

As is clear from the above description, according to the present invention, since graphite is used as the furnace material of the filter device that removes dust from the exhaust gas emitted from the cooling device, it is not only resistant to heat and mechanical shock, but also easy to handle. Instead, the used graphite can be completely incinerated, so no new waste is generated by the furnace material itself.

In addition, the decoking operation can easily remove unburned carbon and cool that have partially adhered to the inside of the cooling system, and during this time, by mixing air into the exhaust gas through the bypass passage, a constant amount of air is constantly supplied to the filter system. Temperature exhaust gas can be introduced.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams of a conventional device, and FIG. 3 is an explanatory diagram of an embodiment of the present invention. 10... Incinerator, 11... Cooling device,
12...Air supply 7 am, 13...Air supply heat transfer tube, 15...Primary filter device, 16...
...Exhaust gas introduction pipe, 17...Furnace material, 21.
...Bypass pipe, G2...High temperature exhaust gas.

Claims (1)

[Claims] IRI waste incinerator exhaust gas cooling device and a filter device for removing dust from the exhaust gas emitted from the cooling device, the furnace material of the filter device is made of graphite, and the inlet of the air supply heat transfer pipe to the cooling device is provided. A bypass pipe for the supply air heat transfer pipe is provided between the side and the exhaust gas introduction pipe to the filter device, and a valve is provided at the entrance of the supply air heat transfer pipe and the bypass pipe, respectively. RI waste incinerator exhaust gas treatment equipment.