JPH0769476B2 - Incineration ash volume reduction processing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for treating combustible miscellaneous solids generated from inside a nuclear power plant, and particularly suitable for solidification treatment / intermediate storage system in granulation treatment of incineration ash. The present invention relates to an incineration ash volume reduction treatment facility suitable for producing pellets.

[Conventional technology]

As a volume reduction process for combustible miscellaneous solids generated from a nuclear power plant, a method for granulating incinerated ash generated after incinerating the combustible miscellaneous solids is discussed in JP-A-60-69600.
However, the incineration ash discharged from the incinerator contains coarse-grained incineration ash and incombustibles (metals) due to differences in incineration operating conditions such as incinerator cleaning process and incineration of replacement parts during regular inspection work. Type) is mixed.

[Problems to be solved by the invention]

The above-mentioned prior art does not consider the selection process of the following incombustible substances contained in the incineration ash discharged from the bottom of the incinerator.

(1) Incineration equipment Incinerated ash generated during the furnace bottom cleaning process.

(2) Coarse particle size incineration ash generated during incineration of replacement parts generated during regular inspection work.

(3) Metallic stiffener, which is an incombustible substance that is mixed into the incinerated ash and discharged when the packing cardboard, etc. is incinerated.

(4) Nail, which is a non-combustible substance that is mixed and discharged in the incinerated ash when a wooden box or the like is incinerated.

(5) Fusner, etc., which is an incombustible substance that is mixed into the incinerated ash and discharged when clothes (work clothes, etc.) are incinerated.

When the incineration ash not suitable for granulation is treated, the following problems occur.

(1) When coarse-grained incineration ash is granulated, it is difficult to secure crushing strength and falling strength of pellets suitable for solidification treatment or intermediate storage system because pellets are formed with non-uniform particle diameters. is there.

(2) When the incineration ash mixed with metal is granulated, the crushing strength of the pellet suitable for the solidification treatment or the intermediate storage system, since the components mixed in the incineration ash will damage the granulator components and foreign matter will enter the pellet. ， It is difficult to secure drop strength.

It is an object of the present invention to provide an incineration ash volume reduction treatment facility capable of increasing the strength of a granulated body of incineration ash, preventing the transfer gas from being discharged to the outside, and simplifying the system configuration.

[Means for solving problems]

The features of the present invention to achieve the above-mentioned object are a combustible miscellaneous solid waste incinerator for incinerating combustible miscellaneous solid waste containing incombustibles generated from a radioactive material handling facility, and the inflammable miscellaneous solid waste incineration. A device for sorting the incineration ash generated in the device into a first incineration ash having a particle size smaller than a preset size and a second incineration ash having a particle size larger than the preset particle size, and an incinerator ash pulverizing device for pulverizing the second incinerator ash to a particle size not larger than the preset particle size. And a transfer gas supply port having a closed opening / closing damper having a large number of through holes, communicating with a lower area below the opening / closing damper, and communicating with an upper area above the opening / closing damper. A gas exhaust port is provided, and a passage for guiding the incinerated ash obtained by crushing by the first incinerated ash and the incinerated ash crusher is connected to the upper region, and an incinerated ash sorting device is selected from the transfer gas. Separate incineration ash And a granulating device that granulates the incinerated ash separated by the separating device, an incinerator using a transfer gas that connects the transfer gas discharge port, the separating device, and the transfer gas supply port in this order. An ash transfer device and means for discharging the incombustibles remaining on the open / close damper to the outside of the lower region when the open / close damper is provided in the incinerator ash sorting device are provided.

[Action]

Since the incinerated ash having a particle size larger than the set particle size is crushed to have the particle size not larger than the set particle size and the incombustibles are separated from the incinerated ash, the strength of the granulated body of the incinerated ash can be increased. A closed loop that connects the transfer gas outlet that communicates with the upper region of the incineration ash sorting device, the separation device, and the transfer gas supply port that communicates with the upper region of the incineration ash sorting device by the incineration ash transport device that uses the transport gas. Therefore, the transfer gas for transferring the incinerated ash containing the radioactive material does not flow out to the outside, and the safety is high.

It has a closed open / close damper having a large number of through holes, a transfer gas supply port communicating with a lower region below the open / close damper is provided, and a transfer gas discharge port communicating with an upper region above the open / close damper is provided. Since the incineration ash sorting device is provided and the passage for guiding the incineration ash obtained by crushing by the first incineration ash and the incineration ash crushing device is connected to the upper region, the incineration ash and the incombustibles are separated. Since the transfer gas for transferring the incinerated ash can be used, the system configuration can be simplified.

〔Example〕

The present invention has been made by conducting the following studies.

Coarse-grained incineration ash can be sorted by a vibrating sieve using a sieve. However, the maximum volume reduction cannot be achieved by selecting coarse particle size incinerated ash with a sieve or the like, filling the drum can, and treating only the uniform particle size incinerated ash here, so this cannot be adopted. Therefore, an incinerator pressure crusher is installed downstream of the switching damper in order to process the coarse particle size incinerated ash contained in the incinerated ash to a particle size that satisfies the granulation processing conditions (particle size 5 mm or less).

As for the selection of metals, it is possible to consider the selection using a sieve, but since it is a sieve (metallic mesh), it is not possible to completely select the metal, so this cannot be adopted. In addition, electromagnetic iron removal utilizing the characteristics of metal is conceivable, but this cannot be adopted because the magnetism of the metal is lost by the incineration process. Therefore, the sorting process is performed by utilizing the difference in specific gravity between the incinerated ash and the metal, which is one of the methods of utilizing the characteristics of the metal. That is, the sorting process is performed by utilizing the fact that the incineration ash mixed with metal is supplied with air at a constant flow rate and a flow rate to flow only the incineration ash having a low specific gravity.

The particle size of incinerated ash generated from the incinerator can be predicted to some extent depending on the operating conditions of the incinerator.

Therefore, since the incineration ash generated during the cleaning process of the incinerator is the total particle size, for example, it is supplied to the incinerator ash crusher using a switching damper and is sized in the incinerator ash particle size range where it can be granulated. . On the other hand, the particle size of the incinerated ash generated during normal operation of the incinerator has a particle size range that can be granulated, so the load on the crusher can be reduced by supplying it to the incinerator ash sorting device using a switching damper. Reduce.

Regarding the supply of incinerated ash to the incinerator ash sorter, a rotary valve is used to supply a fixed amount to prevent complete incineration ash fluidization in the fluidized bed and blockage in the incinerator ash transfer pipe.

In order to completely separate the incinerated ash from the metal in the fluidized bed, by making the fluidized bed a vertical cylinder and supplying air from the lower part and setting the suction nozzle to the upper part, what is sucked from the nozzle is by the supply air. It is only the incinerated ash that fluidizes, and the mixed metals are not transferred to the granulator system.

As described above, a smooth incineration ash granulation process can be performed by sizing the incineration ash particle size range that can be granulated and selecting the metal using the fluidized bed.

An embodiment of the present invention will be described below with reference to FIG. Combustible miscellaneous solids generated from the nuclear power plant are incinerated in the incinerator 1. The incinerator ash discharged from the ceramic filter 2 for removing the incinerator ash contained in the bottom of the incinerator 1 and the smoke is supplied to the incinerator ash crushing device.

The changeover damper 3 receives the incineration ash in the incineration ash crushing device. Here, since the properties of the incineration ash discharged from the incinerator 1 and the ceramic filter 2 can be predicted,
By switching the dampers in advance, the coarse-grained incinerated ash is supplied to the incinerated ash pulverizer 4 to be sized within a grain size range in which granulation is possible. In addition, incinerator ash with a range of particle size that can be granulated does not pass through the incinerator ash crusher, but goes directly to the incinerator ash classifier with a rotary valve
Quantitative supply by 14.

The incineration ash supplied in a fixed amount from the rotary valve 13 or 14 is subjected to a metal sorting process by an air flow using an incinerator ash sorter 5 which is an incinerator ash sorter.

Only the incinerated ash is sucked from the incinerated ash sorter 5 by the suction blower 11 and transferred by the incinerated ash transfer pipe 6. Here, one of the features is that the material is made of ceramic in consideration of wear of the bend portion of the transfer pipe. The transferred incineration ash is collected by the incineration ash cyclone 7 and the incineration ash bag filter 8 in the incineration ash collection system in the suction transfer device, cut out from each rotary valve 15 and 16 and supplied to the incineration ash measuring hopper 10. The suction line from the incineration ash bag filter is provided with an incineration ash HEPA filter 9 to remove the contained dust. The suction line from the incineration ash HEPA filter 9 is connected to the incineration ash sorter via the incineration ash suction blower 11. As described above, the incineration ash sorting device and the incineration ash suction transfer device are configured in a closed loop. In addition, a forced exhaust line is installed in the incineration ash suction blower 11 discharge line to control the negative pressure inside the system to prevent the incineration ash from scattering inside the building (exhaust treatment is shared with existing granulator exhaust treatment equipment). . Negative pressure control is
The pressure inside the system is detected by the discharge part of the incineration ash blower 11 and the pressure adjusting valve 18 is controlled. Regarding the flow rate, the incinerator ash suction blower 11
Control and do 19.

The incineration ash that is cut out from the incineration ash collection system rotary valves 15 and 16 is granulated by the incineration ash metering hopper 10 in one batch processing amount, then cut out by the rotary valve 17 and supplied to the tablet pellet type granulator 12. Granulate.

Next, the structure and function of the incineration ash crusher 4 and the incineration ash sorter 5 which are the application parts of the present invention will be described.

The structure of the incineration ash crusher 4 is shown in FIG. The coarse-grained incineration ash supplied from the switching damper can be granulated with the rotation of the rotor 20 composed of six hexagonal rods 21 and the punching plate (hole diameter 4 mm considering the granulation treatment condition of 5 mm or less). The size is adjusted to the range.

Next, the metal classification method and suction method in the incineration ash sorter 5 will be described with reference to FIG. This is to select the mixed metal in the incinerated ash according to the difference in specific gravity. As shown in FIG. 3, the incinerated ash (mixed with metal) having a granulable particle size is constantly (continuously) supplied to the fluidized bed 23 of the incinerator ash sorter by a rotary valve.

The incinerator ash sorter and the incinerator ash suction / transfer device are configured as a closed loop, and the discharge line of the suction blower is connected to the incinerator hopper 26 of the incinerator ash sorter, and air is sucked into the fluidized bed through the perforated plate damper 25. Only the incineration ash is fluidized by the air sucked here (minimum fluidization flow rate 1 m / s or more), and only the incineration ash is suction-transferred from the suction nozzle 24 installed above the fluidized bed. Granulation treatment 1 The supply of incinerated ash to the fluidized bed is stopped when the transfer of batch is completed. Also, granulation processing 1
After moving the batch, the perforated plate damper 25 is opened to set the metal accumulated in the fluidized bed in advance.
Discharge to 27.

Regarding the example of the incineration ash collection system in the incineration ash suction transfer device, the configurations of the incineration ash cyclone and the incineration ash bag filter were raised, but the equipment configuration shown in Fig. 4 is also possible depending on the incineration ash transfer distance (transfer Distance <25m). That is, only the incinerated ash is sucked from the incinerated ash sorter, the incinerated ash transfer pipe 6 is connected to the incinerated ash weighing and collecting device 30, and the incinerated ash bag filter 9, the incinerated ash suction blower 11 and the incinerated ash classification device are configured in a closed loop. To do. Thereby, the incinerated ash sucked and transferred from the incinerated ash sorting device is transferred to the incinerated ash weighing and collecting device 30 having both the collecting and weighing functions. The bag filter 28 incorporated therein collects the incineration ash when the amount of the first batch process of the granulation process reaches 1 and the damper 29 is opened to supply the collected incineration ash to the granulator.

According to the present embodiment described above, it is possible to select the incineration ash having a particle size capable of being granulated and further to secure the pellet strength suitable for the intermediate storage system.

According to the present embodiment, since it is possible to perform the sizing process within the range of the particle size of the incineration ash for which the coarse particle size can be granulated and to select the metal mixed with the incinerated ash, the following effects can be obtained.

1) Effect on the number of drums generated Fig. 5 shows the effect of reducing the number of drums generated. From Fig. 5, assuming that the number of drums generated when combustible miscellaneous solids generated from a nuclear power plant are directly filled in the drums is 100%,
After incineration, it is 2.5% when filled in a drum (1/40 compared to when filled directly in a drum). In addition, the number of drums generated is 1.7% by granulating the incinerated ash generated after incineration (1/6 compared to when directly filling drums).
0).

2) Effects on granulation treatment a) Significant reduction of damage potential of granulator by selecting metal mixed with incinerated ash.

b) By combining the incineration ash crushing device, the incineration ash sorting device, and the granulating device, it is possible to secure the pellet strength suitable for the solidification process and the intermediate storage system.

The table shows the effect on pellet strength.

According to the present embodiment, it is possible to reduce the volume of waste liquid and combustible miscellaneous solids generated from a nuclear power plant in the same facility (unification treatment).

According to the present invention, it is possible to increase the strength of the granules of incinerated ash, prevent the transfer gas from being discharged to the outside, and simplify the system configuration.

[Brief description of drawings]

FIG. 1 is a schematic flow sheet of an embodiment of the present invention, FIG. 2 is a schematic explanatory view of an incinerator ash crusher, FIG. 3 is a functional explanatory diagram of an incinerator ash sorter, and FIG. 4 is an incinerated ash collection system. FIG. 5 is an explanatory diagram of an embodiment, and FIG. 5 is an explanatory diagram of the incineration ash volume reduction processing effect. 1 ... Incinerator, 2 ... Ceramic filter, 3 ... Switching damper, 4 ... Incinerator ash crusher, 5 ... Incinerator ash sorter, 6
…… Incineration ash transfer pipe, 7 …… Incineration ash cyclone, 8 …… Incineration ash bag filter, 9 …… Incineration ash HEPA filter, 10 ……
Incinerator ash metering hopper, 11 …… Incinerator ash suction blower, 12 …… Granulator, 13 to 17 …… Rotary valve, 18,19 …… Pressure adjusting valve, 20 …… Rotor, 21 …… Hexagonal bar, 22… … Punching plate, 23 …… Fluidized bed, 24 …… Suction nozzle, 25 …… Perforated plate damper, 26 …… Incombustible material discharge hopper, 27 …… Drum can, 28 …… Bag filter, 29 …… Damper, 30 …… Incineration Ash measuring and collecting device.

Claims (1)

[Claims] 1. A combustible miscellaneous solid waste incinerator for incinerating combustible miscellaneous solid waste containing incombustibles generated from a radioactive material handling facility, and incinerator ash generated at the combustible miscellaneous solid waste incinerator. A first incineration ash having a particle size not larger than a set particle size and a second incinerated ash having a particle size larger than the set particle size, an incinerator ash crushing device crushing the second incinerated ash to have a particle size not larger than the set particle size, and a large number of through holes. A transfer gas supply port communicating with a lower region below the open / close damper, and a transfer gas discharge port communicating with an upper region above the open / close damper. And a device for separating the incinerated ash from the transfer gas, and an incinerator ash sorting device in which a passage for guiding the incinerated ash obtained by crushing by the first incinerated ash and the incinerated ash crushing device is connected to the upper region And with the separation device A granulating device for granulating separated incinerated ash, an incinerator ash transfer device using a transfer gas that connects the transfer gas discharge port, the separation device, and the transfer gas supply port in this order, and the incineration An incineration ash volume reduction treatment facility, comprising: means for discharging the incombustibles remaining on the open / close damper to the outside of the lower region when the open / close damper is provided in the ash sorting device. .