JP4295565B2 - How to recover hazardous insulating oil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for recovering harmful insulating oil from a workpiece to which harmful insulating oil such as PCB is attached.
[0002]
[Prior art]
PCB (polychlorinated biphenyl) has been used in many applications such as electrical insulating oil and pressure sensitive paper by utilizing its stability, heat resistance, and insulation properties. It has become clear that it has a high toxicity and is chronically toxic. Its production and use have been discontinued, and manufacturing and importing are prohibited in principle.
[0003]
However, a stable decomposition method for waste PCB oil has not yet been established. The same applies to the processing method for containers and PCB contaminants.
[0004]
For this reason, at present, waste PCB oil and electrical equipment including the same are stored by business operators.
[0005]
However, from the viewpoint of PCB leakage due to accidents associated with long-term storage and the increase in the amount of storage due to the storage of PCB-used equipment that has been used so far, early establishment of PCB pollutant treatment methods is required. ing.
[0006]
Development of chemical treatment methods such as high-temperature incineration at 1100 ° C or higher and catalytic hydrodechlorination (Pd / C method) has been promoted for stable decomposition of waste PCB oil itself. It is said that waste PCB oil can be decomposed and made harmless to a safe level by processing based on these methods.
[0007]
On the other hand, for a method of recovering PCB from electrical equipment filled with PCB oil, a container after draining PCB oil, or secondary contaminants to which PCB has adhered, for example, in the case of a transformer, from within the transformer A method of evaporating and collecting PCB attached to a transformer by vacuum heating after extracting the PCB is known (for example, see Patent Document 1).
[0008]
[Patent Document 1]
JP-A-9-192534 (page 2-4, FIG. 1)
[0009]
[Problems to be solved by the invention]
By the way, when vacuum heating treatment is performed on electrical equipment such as a transformer, containers after draining PCB oil, or secondary contaminants to which PCBs have adhered, these coatings are preliminarily used to prevent the PCB vapor from scattering. It is necessary to store the processed material in a sealed container.
[0010]
In that case, it is conceivable to put an object to be processed in a container, seal the container lid with a molded packing or the like, and seal it with bolts. However, there is a possibility that the sealing surface may be damaged or deformed in repeated use. Moreover, it takes time to attach and detach the bolts to open and close the container lid. In addition, it is necessary to periodically replace the packing and the like, and the working time becomes long. Further, the exchanged packing has a problem that it becomes a secondary contaminant.
[0011]
The present invention has been made to solve such a problem, and it is easy to open and close and seal the lid of a processing container containing a processing object contaminated with a hazardous substance such as PCB. An object of the present invention is to provide a method for recovering harmful insulating oil that can reduce the work time of pretreatment work.
[0012]
[Means for Solving the Problems]
In order to solve such a problem, the method for recovering harmful insulating oil according to the present invention stores a workpiece to which harmful insulating oil such as PCB is attached in a processing container , and receives a seal on the outside of the container main body of the processing container. Is provided over the entire circumference of the container body, and an annular plate provided over the entire circumference of the lid is immersed in the seal liquid accommodated in the seal receiver, so that the gap between the container body and the lid is sealed with the seal liquid. Thereafter, the object to be processed is housed in a vacuum heating furnace together with the processing container and heated under vacuum, and the sealing liquid is evaporated prior to evaporation / recovery of the harmful insulating oil to release the sealing of the processing container. In the method for recovering harmful insulating oil, oil having a vapor pressure lower than that of harmful insulating oil is applied to the sealing liquid, and the upper end of the sealing liquid receiver has a structure higher than the upper end of the container body. Toss It is intended.
[0013]
The sealing liquid, it is desirable to impregnate the impregnation cushion material such as ceramic fiber.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 are schematic configuration diagrams of a PCB recovery process according to the present invention.
[0015]
As shown in FIGS. 1 to 3, the PCB recovery processing step according to the present invention is composed of three processing steps: a pre-processing step A, a vacuum heating processing step B, and a post-processing step C.
[0016]
First, in the preprocessing step A, after unloading the transformer 3 from the transport vehicle 2 at the loading / unloading place 1, the transformer 3 is temporarily stored in the preprocessing storage warehouse 4.
[0017]
The transformers 3 stored in the preprocessing storage warehouse 4 are sequentially taken out to the preprocessing handling area 5 and the PCB is deoiled. That is, as shown in FIG. 4, after removing the eyebolt 6 and the cover 7 from the transformer 3 taken out from the pretreatment storage warehouse 4, the insulating oil PCB is extracted by an oil extraction means 8 such as a pump. Thereafter, the primary insulator 9, the lead wire 10, and the core fixing bolt 11 are removed.
[0018]
Thereafter, the core 14 lifted from the casing 13 by the transfer means 12 such as an overhead crane is transported to the residual liquid removal area D as shown in FIG. 5, and the residual liquid (PCB) is removed. The core 14 from which the residual liquid (PCB) has been removed is again lifted by the transfer means 12 and stored in the processing container 15 as shown in FIG.
[0019]
The processing container 15 includes a container body 16, a container lid 17, and a seal liquid receiver 18. The container body 16 is formed in, for example, a rectangular shape, and a seal liquid receiver 18 is attached to the entire outside thereof. A seal liquid 19 such as water or oil that can be processed in a facility for decomposing or separating PCB is accommodated in the seal liquid receiver 18. An annular plate 20 that is immersed in the sealing liquid 19 is attached over the entire circumference of the rectangular container lid 17. A handle 22 is attached to the upper surface of the container lid 17.
[0020]
Here, a liquid having a vapor pressure lower than that of PCB is used as the sealing liquid. The reason is that the PCB partial pressure in the processing container is reduced, and the amount of PCB evaporation can be suppressed.
[0021]
Moreover, the said processing container 15 may be a rectangular shape, a cylindrical shape, etc., and is not concerned with the shape.
[0022]
Further, in order to prevent the sealing liquid 19 from overflowing outside the sealing liquid receiver 18 due to vibration during conveyance, the end 18a of the sealing liquid receiver 18 is structured higher than the upper end 16a of the container body 16, or There is a method in which the sealing liquid 19 is impregnated in an impregnated cushion material such as ceramic fiber.
[0023]
Next, the vacuum heat treatment step B has a carry-in station 23, a vacuum heat separation facility 24, and a carry-out station 25, and is carried into the carry-in station 23 in the vacuum heat treatment step from the pretreatment handling area 5 in the pretreatment step. The core 14 is housed in the vacuum heating furnace 26 together with the processing container 15 and subjected to vacuum heat treatment.
[0024]
As shown in FIG. 6, the vacuum heating and separation facility 24 includes a vacuum heating furnace 26, a PCB recovery facility 27, and an exhaust treatment facility 28.
[0025]
The inside of the vacuum heating furnace 26 is heated to 250 to 650 ° C. by the heater 29, while being held at 0.01 to 100 mbar by the vacuum pumps 33 and 34.
[0026]
The PCB recovery equipment 27 has an oil shower equipment 31, a cooling condenser 32, vacuum pumps 33 and 34, and an atmospheric pressure cooling condenser 35. The oil shower equipment 31, the cooling condenser 32, and the atmospheric pressure cooling condenser 35 are respectively collected. A tank 36 is provided. The oil shower facility 31 collects PCB by ejecting oil a in the tank 37 from the nozzle 38 into the tank 37. A circulation line 40 and a heat exchanger 41 are provided in a conduit 39 for supplying the oil a in the tank 37 to the nozzle 38.
[0027]
The PCB recovered in each recovery tank 36 passes through the pipe 42 and is rendered harmless at a chemical decomposition treatment facility (not shown). On the other hand, the exhaust treatment facility 28 is provided with an activated carbon filter 43.
[0028]
Now, when the core 14 is carried into the vacuum heating furnace 26 together with the processing container 15 and heated to a predetermined temperature (250 to 650 ° C.) under vacuum (0.01 to 100 mbar), first, the sealing of the processing container 15 is performed. The sealing liquid 19 accommodated in the liquid receiver 18 evaporates, and the sealing of the processing container 15 is released as shown in FIG.
[0029]
As described above, when the sealing of the processing container 15 is released, the PCB vapor obtained by evaporating the PCB remaining in the core 14 is transferred between the sealing liquid receiver 18 and the annular plate 20 provided around the container lid 17. It flows out of the gap and is recovered by the PCB recovery facility 27.
[0030]
As shown in FIG. 3, the core 14 from which the PCB has been removed by the vacuum heating / separation facility 24 is unloaded together with the processing container 15 to the unloading / shipping place 44 in the post-processing step C via the unloading station 25, and then post-processed. It is stored in the storage warehouse 45. Thereafter, the core 14 from which the PCB has been removed is taken out from the processing container 15, and then disassembled, reduced, and pulverized by the disassembling device 47, the volume reducing device 48, and the pulverizing device 49 at the post-processing site 46, and then the packaging container 50 and packed in a pre-shipment storage warehouse 51. Thereafter, it is shipped by a transport vehicle (not shown) and reused.
[0031]
Here, a part of the core 14 from which the PCB is removed is sampled, and the presence or absence of the PCB is analyzed in the analysis chamber 53. On the other hand, the used processing container 15 is returned to the preprocessing handling area 5 of the preprocessing step and reused.
[0032]
In the above description, the case where the transformer core 14 is subjected to vacuum heat treatment has been described. However, the transformer casing 13 can also be subjected to vacuum heat treatment in the same manner as the core 14. The transformer casing 13 may be subjected to a solvent cleaning treatment if desired.
[0033]
【The invention's effect】
As described above, according to the present invention, the object to be treated to which harmful insulating oil such as PCB is attached is stored in a processing container, and then the gap between the main body of the processing container and the lid is sealed with a sealing liquid. In order to release the sealing of the processing container by storing the processing object together with the processing container in a vacuum heating furnace and heating it under vacuum to evaporate the sealing liquid prior to evaporation / recovery of the harmful insulating oil. It is easy to open and close and seal the lid of a processing container that accommodates an object to be processed contaminated with a hazardous substance such as PCB.
[0034]
Accordingly, it is possible to shorten the time for preprocessing work such as opening / closing the lid of the processing container and sealing work, and to improve the work efficiency of the preprocessing work. In addition, effects such as a reduction in the contact degree of PCB contaminants by workers, reduction of PCB contamination of the apparatus, and reduction of contamination of the work environment can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a pretreatment step in a hazardous insulating oil recovery method of the present invention.
FIG. 2 is a schematic configuration diagram of a vacuum heat treatment step in the hazardous insulating oil recovery method of the present invention.
FIG. 3 is a schematic configuration diagram of a post-processing step in the hazardous insulating oil recovery method of the present invention.
FIG. 4 is an explanatory diagram of oil removal and separation work in a pretreatment process.
FIG. 5 is an explanatory diagram of a residual liquid removing operation in a pretreatment process.
FIG. 6 is a cross-sectional view of a processing container.
FIG. 7 is a schematic configuration diagram of vacuum heating separation equipment.
FIG. 8 is an explanatory view of a processing container in which the sealing liquid is evaporated and the sealing is released.
[Explanation of symbols]
14 To-be-processed object 15 to which harmful insulating oil such as PCB is attached 15 Processing container 16 Main body of processing container 17 Lid 19 Seal liquid 26 Vacuum heating furnace

Claims (2)

A processing object to which a harmful insulating oil such as PCB is attached is stored in a processing container, and a seal receiver is provided on the outer periphery of the container main body of the processing container over the entire circumference of the container main body, and a sealing liquid stored in the seal receiver. An annular plate provided over the entire circumference of the lid is immersed in the container, and the gap between the container body and the lid is sealed with a sealing liquid, and then the object to be treated is placed in a vacuum heating furnace together with the processing container. In the method for recovering harmful insulating oil, the sealing liquid is evaporated and the sealing liquid is released before the harmful insulating oil is evaporated and recovered, and the sealing liquid has a vapor pressure higher than that of the harmful insulating oil. A method for recovering harmful insulating oil, characterized in that low oils are applied and the upper end of the seal liquid receiver is structured higher than the upper end of the container body . The method for recovering harmful insulating oil according to claim 1 , wherein the sealing liquid is impregnated in an impregnated cushion material such as ceramic fiber .

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