KR20210147881A - Washing system for transformer and washing method using the same - Google Patents

Abstract

The present invention aims to efficiently clean a transformer polluted with polychlorobiphenyl by using a small amount of a cleanser. Provided is a cleaning system for cleaning a transformer, which at least comprises: a gasifying cleaning chamber, a heating apparatus, a cooler, a cleanser storage container accessed to the cooler, a liquid pump accessed to the cleanser storage container, a liquefying apparatus, and a pressure-reducing apparatus. By using the cleaning system, the transformer polluted with polychlorobiphenyl is disposed inside the gasifying cleaning chamber, and the cleanser is supplied into the gasifying cleaning chamber. The pressure inside the gasifying cleaning chamber is lowered to be lower than the atmospheric pressure, and the gasifying cleaning chamber is heated to gasify the cleanser. The transformer is cleaned by the gasified cleanser, and the gasified cleanser is liquefied by the cooler and the liquefying apparatus. The liquefied cleanser is temporarily stored in the cleanser storage container, and the temporarily stored cleanser is returned into the transformer placed in the gasifying cleaning chamber by using the liquid pump.

Description

Transformer cleaning system and cleaning method using the same

The present invention relates to a system for cleaning oil remaining in a transformer with a cleaning agent and a cleaning method of a transformer using the same.

Nowadays, environmental pollution is becoming a serious problem, and it is difficult to dispose of industrial waste as it is. In particular, industrial wastes containing hazardous substances need to be removed by washing or the like. For example, polychlorinated biphenyl has good electrical insulation and is well soluble in organic solvents and oils, so it has been widely used in transformers (transformers) of electrical equipment, insulating oil of capacitors, adhesives, waxes, lubricating oils, and the like. However, polychlorinated biphenyls are highly toxic to the living body, such as carcinogenicity, skin disorders, visceral disorders, and hormone abnormalities, and are easily accumulated in adipose tissue, so production is currently prohibited. Accordingly, wastes such as electrical equipment produced and used when the use of polychlorinated biphenyl is recognized requires removal of polychlorinated biphenyl by washing. However, the transformer, which is an electric device in which mineral oil containing polychlorinated biphenyl is used as an insulating oil, has a large amount of insulating oil used therein, and its internal structure is complicated, making it difficult to clean, and is stored without washing. It is known that transformers exist in large quantities. Among them, there are a large number of small transformers with a body weight of about 500 kilograms, and they are left unattended in large quantities because cleaning operation of contaminants is difficult.

Conventionally, cleaning of insulating oil containing polychlorinated biphenyl remaining in electrical equipment has been accomplished by placing the electrical equipment in a cleaning tank, immersing it in a cleaning solvent and washing it off. For example, in Patent Document 1, a first process of placing an object to be treated contaminated with PCB in a sealable cleaning container, evacuating the inside of the cleaning container, containing a hydrocarbon-based liquid cleaner, ultrasonic cleaning or shaking cleaning; The vacuum cleaning process method which repeats the 2nd process which removes a cleaning agent is proposed. Patent Document 2 discloses a cleaning system and a cleaning method that improve the disadvantages of the vacuum cleaning treatment method of Patent Document 1, respectively.

(Prior art literature)

(Patent Literature)

(Patent Document 1) Japanese Patent Laid-Open No. 2003-145069

(Patent Document 2) Japanese Patent Laid-Open No. 2017-189738

Conventionally, in a general cleaning operation, it was necessary to carry a transformer into a cleaning tank or a cleaning container. As disclosed in Patent Document 1, in the conventional cleaning operation, since a transformer must be immersed in a cleaning tank filled with a cleaning solvent, a large amount of cleaning solvent is required, and there is a problem in that the amount of waste liquid to be treated increases. Moreover, the container-shaped thing like a transformer could not fully clean the inside of a container. A transformer having a large amount of laminates disposed therein has a complicated internal structure, so it is difficult to dismantle it, and there is a problem in that cleaning stains are found after cleaning. On the other hand, a method of incineration without cleaning the small transformer may be considered, but incineration of the transformer is expensive and the treatment efficiency is low. The cleaning system and cleaning method of Patent Document 2 were innovative in terms of being able to solve these conventional problems. However, further improvement is needed to more efficiently clean the inside of a transformer having a complex structure.

The present invention provides a method in which waste liquid or exhaust is not generated as much as possible in the oil containing polychlorinated biphenyl in a plurality of transformers (hereinafter referred to as 'contaminated oil containing PCB, etc.' or simply 'contaminated oil') in a plurality of transformers. Disclosed are a cleaning system and a cleaning method using the same, which simultaneously remove with a small amount of cleaning agent and make a transformer in a disposable state.

One aspect of the present invention is a cleaning system for cleaning a transformer, comprising at least a vaporization cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device, ,

A transformer contaminated with polychlorinated biphenyl is placed inside the evaporative washing tank, a cleaning agent is supplied to the inside of the evaporative washing tank, the inside of the evaporative washing tank is set to a pressure lower than atmospheric pressure, and the evaporative washing tank is heated After vaporizing the cleaning agent and cleaning the transformer with the vaporized cleaning agent, the vaporized cleaning agent is liquefied by the cooler and the liquefaction device, and the liquefied cleaning agent is temporarily stored in the cleaning agent storage container, the It is the cleaning system for cleaning the transformer in a closed or semi-closed system, characterized in that the temporarily stored cleaning agent is directly refluxed into the transformer disposed inside the vaporization cleaning tank using the liquid feeding pump.

In another aspect of the present invention, at least a vaporization cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device are included. A method for cleaning a transformer contaminated with polychlorinated biphenyl in a closed or semi-closed system using the system, comprising the following steps:

disposing the transformer inside the evaporative washing tank,

Supplying a cleaning agent to the inside of the evaporative cleaning tank,

to a pressure lower than atmospheric pressure inside the vaporization washing tank,

Heating the evaporative washing tank to raise the temperature inside the evaporative washing tub to above the boiling point of the washing agent to vaporize the washing agent inside the evaporating washing tub;

cleaning the transformer with the vaporized cleaning agent,

The vaporized cleaning agent is liquefied by the cooler and the liquefaction device, the liquefied cleaning agent is temporarily stored in the cleaning agent storage container, and the temporarily stored cleaning agent is placed inside the vaporized cleaning tank using the liquid feeding pump refluxing the inside of the transformer

It is a method of cleaning the transformer, including.

In the method of cleaning a transformer, it is preferable to further include a step of liquefying the vaporized cleaning agent and discharging the liquefied cleaning agent to the outside of the vaporized cleaning tank.

By using the system of this embodiment, it is possible to simultaneously clean a plurality of transformers contaminated with polychlorinated biphenyls present in large quantities. The cleaning method of a transformer contaminated with a PCB etc. using the system of this embodiment makes it possible to directly clean the inside of a small transformer in which a drain valve or the like cannot be installed, and does not require a large space for cleaning operation, and Efficient cleaning that is a substantially closed system with a small amount of cleaning agent usage is attained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining the washing|cleaning system which concerns on one Embodiment of this invention.
2 is a schematic diagram illustrating a cleaning system according to the prior art.

A transformer, which is an object to be cleaned using the system according to the embodiment, is an electric power device that converts a voltage of AC power, and has a plurality of magnetically coupled coils as main components. Transformers include oil-immersed transformers, molded transformers, and gas transformers depending on the type of insulator. In this specification, in particular, oil-immersed transformers using oil as an insulator are referred to. Oil-immersed transformers include large equipment with an oil capacity of tens of thousands to hundreds of thousands of liters, medium-sized equipment with hundreds to thousands of liters of oil, and small equipment with a capacity of several hundred liters or less. In the past, polychlorinated biphenyls were used in the insulating oil of oil-injected transformers, and transformers with polychlorinated biphenyls remain in large quantities without being treated. As such, it is difficult to dispose of, so the remaining transformer is the object of cleaning in this form. The system according to the embodiment is used particularly advantageously for cleaning of small transformers, in which a drain valve or the like cannot be directly installed.

Polychlorinated biphenyl (hereinafter referred to as "PCB"), which is an object to be removed using the system of the present embodiment, is a generic term for 209 types of isomers that differ in the number and position of chlorine present in a molecule, and a specific one I am not referring to compounds.

The system of the present embodiment includes at least a vaporization cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device. The evaporative cleaning tank is a container for installing a transformer cleaning using the system therein. The evaporative washing tank is mainly composed of a container portion capable of accommodating a plurality of transformers, and a partition portion for installing the transformers. The container part is a solution part of a vaporization washing tank, and a partition part is a plate-shaped member for arrange|positioning a transformer. The container portion is formed of a metal or plastic material capable of withstanding a depressurization operation. It is preferable that the partition is a grid type, and wood, wire mesh, grating, etc. may be used. The container unit has a volume capable of arranging at least a plurality of small transformers having an oil capacity of several hundred liters (for example, five or more) or medium-sized transformers having a capacity of several hundred to several thousand liters. By using the evaporative cleaning tank having such dimensions, it becomes possible to simultaneously clean a plurality of small transformers. As described above, the partition part is a plate-shaped member such as wood, wire mesh, or grating having a grid shape, and the inside of the evaporative cleaning tank can be divided into a transformer accommodating part and a cleaning agent introduction part. On the other hand, the evaporative cleaning tank needs to be made of a material having durability against the cleaning agent. It is preferable that the evaporative cleaning tank is formed of a metal or plastic material. A liquid storage container for storing the detergent may be installed inside the vaporized washing tank, and the detergent may be placed there. Here, the cleaning agent is preferably one capable of dissolving or at least dispersing the contaminant oil remaining in the transformer and having a lower boiling point than the contaminant oil. As such a cleaning agent, a hydrocarbon-based solvent, a halogen-based solvent, or the like can be used. For example, an alkane, alkene, cycloalkane or cycloalkene solvent having 8 to 15 carbon atoms (especially an alkane or alkene solvent having 11 to 13 carbon atoms) or a halogen solvent having 1 to 12 carbon atoms can be used. have. Specifically, Aquasolvent G71 (Aqua Chemical Co., Ltd.), HC-370 (Toso Co., Ltd.), MD-250 (Musa Technochemical Co., Ltd.), Linpar12 (Sasol Limited), MACSOL-P (NSI Corporation), etc. can use the commercially available solvent which has dodecane as a main component. In other cases, it is also possible to use water, a water-based solvent, alcohol, or the like.

As the heating device, any heating device capable of heating at least a part of the evaporative cleaning tank may be used. For example, a means for directly or indirectly heating the inside of the evaporative cleaning tank container part, such as a ribbon heater, a steam heater, an oil bus, an electric heater, an electromagnetic heater, is mentioned. The heating device may be installed inside the vaporization washing tank or outside the vaporization washing tank.

The cleaning agent recovery container is a container for recovering the contaminated cleaning agent generated after cleaning the contaminated transformer using the system of the present embodiment, and can be connected to the cleaning system of the embodiment. As described above, since hydrocarbon-based solvents, halogen-based solvents, etc. can be used as the cleaning agent, it is preferable that the cleaning agent recovery container also has durability capable of storing these solvents.

The cooler is connected to the evaporative cleaning tank. The cooler is for cooling and condensing the cleaning agent vaporized in the vaporization cleaning tank, and refluxing it into the vaporization cleaning tank as a liquid again. Any type of cooler may be used as long as it can cool and condense the vaporized cleaning agent, but, for example, a reflux condenser may be used. A chiller may be installed in the cooler to assist cooling of the vaporized detergent, or the temperature of the liquid detergent refluxed into the vaporized cleaning tank may be adjusted.

The detergent reservoir is connected to the cooler. The detergent storage container is a container for temporarily storing (storing) the liquid detergent vaporized in the vaporization cleaning tank and condensed with a cooler. The vaporized cleaning agent flows into the cooler from the vaporized cleaning tank, and the cleaning agent cooled by the cooler is at least temporarily stored in the cleaning agent storage container. The stored cleaning agent is refluxed into the evaporative cleaning tank using a liquid feeding pump described below.

The liquid feeding pump is connected to the detergent storage container. The liquid feeding pump refluxes the liquid detergent temporarily stored in the detergent storage container to the vaporized cleaning tank. The cleaning agent refluxed to the evaporative washing tank by the liquid feed pump is refluxed into the evaporative washing tank. In this case, the cleaning agent may be refluxed directly into the transformer disposed inside the vaporization cleaning tank by using a liquid feeding pump.

The liquefaction apparatus is for capturing and separating the vaporized detergent that has not been fully cooled by the cooler described above. In order to operate the present system in a closed or semi-closed system in which the discharge of the organic cleaning agent to the outside is reduced as much as possible, it is highly desirable to provide a liquefaction device. Any type of liquefaction apparatus may be used as long as it is capable of capturing and separating the vaporized cleaning agent, but, for example, a demister or a heat exchanger may be used. In addition, an activated carbon tower may be additionally installed in order to finally and completely capture the detergent etc. which have not been completely captured by the liquefaction apparatus. A chiller may be installed in the cooler to aid in cooling the vaporized detergent or to adjust the temperature of the liquid detergent.

The pressure reducing device is for depressurizing the entire system. By depressurizing the whole system with a pressure reducing device, the temperature at which the cleaning agent is vaporized can be lowered. Any type of pressure reducing device may be used as long as it can depressurize the entire system, but for example, a vacuum pump may be used. The pressure reducing device may be provided with a device for adjusting the degree of pressure reduction in the system (that is, the pressure in the system), for example, pressure detecting means.

The system of the embodiment includes these devices, piping for connecting these devices, and an appropriate number of on-off valves, and these can be arranged in the receiving means. As the storage means, it is possible to use a container capable of arranging each device at a predetermined position, such as a storage rack or storage container. By arranging each device compactly in the housing means in this way, the entire system can be made portable. If the system composed of these devices is loaded on a moving means such as one vehicle, the entire system can be moved to the site even if the place where the contaminated transformer is stored is far away. As the storage means for accommodating the respective devices, a decomposable one may be used. In this way, the entire system can be properly disassembled and loaded in various shapes on a moving means, and the system can be properly assembled at a place where the contaminated transformer is stored.

Next, a method of cleaning a transformer contaminated with a contained contaminated oil such as a PCB using the cleaning system of the present embodiment will be described. The cleaning method of this embodiment includes at least a vaporization cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device. A cleaning system for cleaning a transformer. This is a method to clean a transformer contaminated with polychlorinated biphenyl using The cleaning method according to this embodiment includes the following steps: placing a transformer inside the evaporative cleaning tank, supplying a cleaning agent to the inside of the evaporating cleaning tank, setting the inside of the evaporating cleaning tank to a pressure lower than atmospheric pressure, heating the evaporative cleaning tank, The inside of the evaporative cleaning tank is heated to above the boiling point of the cleaning agent, the cleaning agent is vaporized inside the evaporative cleaning tank, the transformer is cleaned with the vaporized cleaning agent, the vaporized cleaning agent is liquefied by a cooler and a liquefaction device, and the liquefied cleaning agent is Temporarily storing the cleaning agent storage container, and refluxing the temporarily stored cleaning agent to the inside of the transformer disposed inside the evaporative cleaning tank using a liquid feeding pump. The cleaning method of the present embodiment is based on washing off the contaminated oil in the transformer with a cleaning agent. It is known that, in a transformer having an iron core having a structure in which a plurality of iron plates are stacked, contaminant oil remains between the stacked iron plates and the iron plates, and it is very difficult to completely clean the residual oil. First, by supplying a cleaning agent to the inside of the evaporative cleaning tank and heating the evaporative cleaning tank to vaporize the cleaning agent supplied to the inside, the contaminated oil present inside the transformer arranged inside the evaporative cleaning tank is dissolved or dispersed in the cleaning agent . Here, vaporization generally refers to a phenomenon in which a liquid is transformed into a gas, and is a concept including evaporating on the surface of the liquid and boiling within the liquid. When a liquid detergent is supplied to the inside of the evaporative cleaning tank or the inside of the transformer and then heated, first, evaporation occurs on the surface of the cleaning agent. When the temperature inside the evaporative cleaning tank or inside the transformer rises and immediately reaches the boiling point of the cleaning agent, boiling occurs inside the cleaning agent, and the cleaning agent is completely vaporized. The vaporized cleaning agent diffuses into the space inside the vaporized cleaning tank, reaches the inside of the arranged transformer, and contacts the components inside the transformer.

Here, a structure in which the vaporized cleaning agent cleans the contaminant oil remaining inside the transformer is described. It is very difficult to clean an object having a structure in which a plurality of plates are stacked, such as a winding disposed inside a transformer, as it is. However, according to Quasi two-dimensional boiling under reduced pressure (Proceedings of the First Pacific Thermal Engineering Conference, PRTEC, March 13-17, 2016) by Matsumoto et al., under reduced pressure, the vaporized solvent penetrates into the gaps in the laminate and , a phenomenon in which the solvent in the gap is replaced while repeating condensation and turning can be seen. When the vaporized solvent is brought into contact with the laminate while adjusting the pressure inside the sealed container, the vaporized detergent enters the gaps in the laminate and dissolves or disperses the contaminant oil present in the gap, causing condensation and Dolby It is assumed to be replaced with a new cleaner while repeating. The present embodiment is a method of cleaning even the gap portion of the laminate by contacting the vaporized cleaning agent with the inside of the transformer contaminated with the contaminated oil, paying attention to this point of view. In particular, in the method of this embodiment, the inside of a transformer can be especially efficiently cleaned by periodically changing the pressure inside the vaporization washing tank in a substantially sealed state. For example, if the pressure inside the evaporative cleaning tank is lowered (for example, about 2 kilopascals or less) and the temperature is raised, all of the cleaning agent is vaporized and penetrates into the interior of the evaporative cleaning tank and the fine internal structure of the transformer. After washing continuously in this state, if the pressure inside the vaporized washing tank is increased (for example, to about 30 kilopascals), the vaporized detergent is condensed and the volume is rapidly reduced. On the other hand, when the liquid detergent is sprayed on the fine internal structure of the transformer in conjunction with increasing the pressure inside the vaporized washing tank, the vaporized detergent is condensed and the liquid detergent is attracted to the portion with a reduced volume at once. This phenomenon is the above-mentioned 'a phenomenon in which the vaporized solvent enters the gap portion of the laminate under reduced pressure, and the solvent in the gap portion is replaced while repeating condensation and bumping'. In this way, the vaporized cleaning agent and the liquid cleaning agent are replaced by the complicated structure (the gap between the laminates, etc.) inside the transformer, and cleaning proceeds. In addition, in this embodiment, there is no need for a special apparatus for vaporizing a cleaning agent, and the cleaning agent inside a vaporization washing tank is directly vaporized using a heating device. Therefore, an extensive space is not required for implementation of the present embodiment.

Next, with reference to FIG. 1, the washing|cleaning method of this embodiment is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining typically the washing|cleaning method of this embodiment. In FIG. 1, reference numeral 1 denotes a vaporization cleaning tank, reference numeral 32 a detergent storage container, reference numeral 4 a heating device, and reference numeral 101 a container part. The transformer 10 is a so-called oil-immersed transformer, and is a transformer using oil as an insulator. The transformer 10 is mainly composed of an iron core 11, a winding 12, an insulating material 13 (ie oil, not shown), a tap change device 14 and an insulating oil chamber 15, Components of other transformers made of paper, wood, ceramics, etc. are not shown. In this figure, the transformer 10 is a small device having an oil capacity of several hundred liters or less.

The transformer 10 contaminated with the contaminated oil containing PCB, etc. is installed on the partition plate 102 installed inside the evaporative cleaning tank 1 . Although it differs depending on the volume of the container part 101 of the vaporization washing tank 1, the contaminated transformer 10 can arrange|position a plurality, such as five or more, for example. The cleaning agent is supplied to the liquid storage container 31 installed in the lower part (lower part of the partition plate 102) inside the vaporization cleaning tank 1 . As the cleaning agent, a liquid capable of dissolving or at least dispersing the contaminated oil remaining inside the transformer 10 and having a lower boiling point than the contaminated oil is preferable. As such a cleaning agent, a hydrocarbon-based solvent or a halogen-based solvent can be used. For example, an alkane, alkene, cycloalkane or cycloalkene solvent having 8 to 15 carbon atoms (especially an alkane or alkene solvent having 11 to 13 carbon atoms) or a halogen solvent having 1 to 12 carbon atoms can be used. have. Specifically, Aquasolvent G71 (Aqua Chemical Co., Ltd.), HC-370 (Toso Co., Ltd.), MD-250 (Musa Technochemical Co., Ltd.), Linpar12 (Sasol Limited), MACSOL-P (NSI Corporation), etc. can use the commercially available solvent which has dodecane as a main component. In other cases, it is also possible to use water, a water-based solvent, alcohol, or the like.

The cleaning agent is introduced and the pressure reducing device (vacuum pump 81) is operated to depressurize the inside of the evaporative cleaning tank 1 to a pressure lower than atmospheric pressure. The vaporization washing tank 1 is heated by the heating device 4 provided at the bottom and/or surrounding part of the vaporization washing|cleaning tank 1 with the pressure reducing device in operation. As the heating device 4, any heating mechanism capable of heating at least a part of the vaporization cleaning tank 1 can be used. As a heating apparatus, a means for heating the vaporization washing tank 1 directly or indirectly, such as a ribbon heater, a steam heater, an oil bus, an electric heater, an electromagnetic heater, etc. is mentioned, for example. In FIG. 1, the heating device 4 is provided in the lower inner side of the vaporization washing tank 1 and the peripheral part. When the vaporization cleaning tank 1 is heated using the heating device 4 , the temperature inside the container portion 101 rises, and vaporization of the cleaning agent inside the liquid storage container 31 starts. The vaporized cleaning agent is diffused throughout the interior of the vaporized cleaning tank 1 , and is also diffused inside the arranged transformer 10 . What is necessary is just to perform heating by the heating device 4 to the temperature at which a cleaning agent is vaporized (evaporated). However, preferably, the inside of the evaporative cleaning tank 1 is heated so that the temperature at which the cleaning agent boils, ie, the boiling point of the cleaning agent or more, becomes higher. The vaporized cleaner diffused throughout the vaporized cleaning tank 1 comes into contact with the inner wall of the transformer 10 or the surface of the component parts of the transformer 10 and condensed, and the contamination remaining inside the transformer 10 with high affinity with the cleaner Dissolved or dispersed in oil-batch detergents. As described above, inside the transformer 10, various components such as the iron core 11, the winding 12, and the tap changer 14 are arranged so that the structure is very complicated. spread evenly to When the vaporized cleaner comes into contact with the inside of the transformer 10 and the components, the vaporized cleaner is condensed to dissolve or disperse the contaminated oil in the part. The part where the dissolution or dispersion of the contaminated oil by the vaporized detergent occurs is heated by the heat of condensation. Thereby, a temperature distribution arises in the part which is in contact with the vaporized cleaning agent in the transformer 10, and the part which does not. Then, the supplied vaporized cleaning agent tends to be condensed in the portion where cleaning is not yet performed or the temperature is low. In this way, it is possible to uniformly clean the inside of the transformer 10 . In this way, the cleaning agent supplied to the inside of the transformer 10 dissolves or disperses the contaminated oil remaining inside the transformer 10 . The vaporized detergent is discharged from the vaporized washing tank 1 and flows into the cooler 51 . In the cooler 51 , the vaporized detergent is cooled with the help of the chiller 61 in some cases, and the liquefied detergent is stored in the detergent storage container 32 . On the other hand, when an opening (not shown) is installed at the bottom of the arranged transformer 10, the cleaning agent in which the contaminant oil remaining inside the transformer 10 is dissolved or dispersed is discharged to the outside of the transformer 10 through the opening, and the grid It passes through the mold partition plate 102 and stays in the liquid storage container 31 .

Here, the amount of the cleaning agent supplied to the inside of the evaporative cleaning tank 1 may be changed according to the total amount of the capacity of the transformer to be cleaned. For example, if 20% or less, particularly 10% or less of the cleaning agent of the total amount of the evaporative cleaning tank 1 is supplied, the evaporative cleaning agent can be diffused throughout the inside of the evaporative cleaning tank 1 and the transformer 10, It is possible to completely dissolve or disperse the contaminated oil present in the transformer 10 . In some cases, it is also possible to clean all the contaminated oil inside the transformer 10 only by supplying a cleaning agent of 5% or less of the total amount of the capacity of the vaporization cleaning tank 1 . For example, if the volume of the evaporative washing tank 1 is 10,000 liters, 500 liters of, in some cases, less than 400 liters of cleaning agent may be supplied into the evaporative washing tank 1 . In addition, heating by the heating device 4 may be performed to the extent that the cleaning agent supplied in the vaporization cleaning tank 1 reaches the temperature at which it vaporizes, Preferably it may be performed to such an extent that it reaches the boiling point of a cleaning agent. Although it varies depending on the internal pressure of the vaporization washing tank 1, when washing is performed by maintaining the internal pressure of the vaporization washing tank 1 at a pressure lower than atmospheric pressure, in general, the inside of the vaporization washing tank 1 is 50° C. to 250° C., preferably What is necessary is just to heat so that it may become a temperature in the range of 100 degreeC - 200 degreeC.

In this way, when the pressure reducing device is provided in the system of the embodiment, the cleaning agent can be vaporized at a relatively low temperature. Since the inside of the system is made at a lower pressure than the outside, the cleaning agent does not leak to the outside, and it is possible to prevent the cleaning agent from being ignited. As the pressure reducing device, any one may be used as long as it can depressurize the inside of the evaporative washing tank 1, for example, connected to either the evaporative washing tank 1 or the cleaning agent flow path through a pressure reducing flow path. You can use a vacuum pump. In FIG. 1, the aspect which provided the vacuum pump 81 is shown. For example, when dodecane is used as the cleaning agent, the cleaning agent can be vaporized when the temperature in the transformer is set to about 200°C by using a pressure reducing device to adjust the system pressure to about 0 to 70 kPa. In addition, the on/off valves (201, 202, 203, 204 in the drawing) for opening and closing the flow passages are installed in the cleaning agent flow path and the pressure reducing flow path, and by opening and closing the on/off valve, the pressure in the evaporative cleaning tank 1 is reduced Alternatively, the condensed cleaning agent can be refluxed directly to the transformer. Although not shown, a line for introducing and discharging the cleaning agent is also provided.

Although not shown, pressure detection means for detecting the pressure in the vaporization washing tank 1 may be provided. Thereby, it can be confirmed in advance whether the inside of the transformer 10 is pressure-reduced. Moreover, based on the information detected by the pressure detection means, it is also possible to control the on-off valve and adjust the pressure in the vaporization washing tank 1 . By using the pressure detecting means, for example, the pressure in the evaporative cleaning tank 1 can be lowered to about 2 kilopascals, and almost all of the cleaning agent can be vaporized to perform cleaning of the transformer 10 . Next, when the pressure in the vaporized cleaning tank 1 is raised to about 30 kilopascals, a part of the vaporized cleaning agent is rapidly liquefied, and the volume of the cleaning agent is rapidly reduced. On the other hand, the vaporized cleaning agent is liquefied by the cooler 51 and the liquefaction apparatus (for example, a demister) 7 . The liquid detergent is temporarily stored in the detergent storage container (32). The liquid detergent temporarily stored in the detergent storage container 32 is refluxed by spraying it into the transformer 10 through the pipe using the liquid feed pump 83 . Then, the vaporized detergent is rapidly liquefied, and the liquid detergent sprayed to the location where the volume has been reduced is sucked in at once, and the vaporized detergent and the liquid detergent are exchanged. By this phenomenon, the cleaning agent reaches the complex structure inside the transformer 10 , and it is possible to completely clean the inside of the transformer 10 . In addition, by directly spraying the liquid detergent temporarily stored in the cleaning agent storage container 32 into the transformer 10, the cleaned cleaning agent (contaminated cleaning agent) that does not fall easily from the components inside the transformer 10 and is easy to remain. ) is physically washed down, and the effect of dropping it to the lower part of the evaporative washing tank (1) can also be expected. As described above, by periodically changing the pressure in the vaporization cleaning tank 1 by using the pressure detecting means as needed, the liquid cleaning agent remaining in the cleaning agent storage container 32 is refluxed into the transformer from time to time, so that the inside of the transformer is more efficiently can be cleaned.

Although not shown, an inert gas supply tank capable of supplying an inert gas such as nitrogen or rare gas, an inert gas supply passage connecting the gas supply tank and the vaporization cleaning tank 1, and the inert gas supply passage are opened and closed You may install an on/off valve for inert gas for this purpose. With these facilities, when the pressure detecting means detects an abnormal pressure, the heating by the heating device 4 can be stopped, and the inert gas can be supplied into the vaporization cleaning tank 1 . That is, in an emergency, by supplying an inert gas into the vaporization cleaning tank 1, the system in a heated state can be shifted to a safe state. Moreover, by supplying an inert gas to the inside of a vaporization washing tank using these facilities, the pressure inside a vaporization washing tank can also be raised rapidly.

The cleaning method of the embodiment can be performed in a closed system or a semi-closed system for a predetermined period of time. After the cleaning operation is finished, heating by the heating device 4 is stopped, and the vaporization cleaning tank 1 is cooled. Although the means for cooling the vaporization cleaning tank 1 itself is not shown in FIG. 1 , if a cooling means is provided in the vaporization cleaning tank 1 , the heated vaporization cleaning tank 1 can be cooled quickly. When the temperature inside the vaporization cleaning tank 1 decreases, the cleaning agent contaminated by cleaning and the vaporized cleaning agent are liquefied and remain together at the bottom of the vaporization cleaning tank 1 . The cleaning agent remaining at the bottom of the vaporized cleaning tank 1 is discharged to a cleaning agent recovery container (not shown) to recover it. In this way, the oil contaminated with the PCB or the like can be discharged from the evaporative cleaning tank 1 . The collected contaminated cleaning agent can be disposed of, for example, by incineration or the like at a treatment facility that has received certification for detoxification treatment in each country. In addition, the cooling of the vaporization washing tank 1 is started while the pressure inside the vaporization washing tank 1 is kept low to some extent, the temperature inside the vaporization washing tank 1 is lowered, and the temperature is completely returned to room temperature. While discharging the liquefied cleaning agent as described above to a cleaning agent recovery container (not shown) before coming, the cleaning agent attached to the inside of the transformer 10 disposed inside the vaporized cleaning tank 1 may be dried.

After the cleaning operation of the transformer 10 described above, the vaporization cleaning tank 1 is opened to take out each transformer, and each of these transformers can be disassembled and classified by component parts. For example, if the transformer 10 is classified by component parts, it can be largely classified into an iron core 11 , a winding 12 , a tap changer device 14 , and an insulating oil chamber 15 . The iron core 11 includes a wound iron core in which a plurality of silicon steel strips are laminated or a hematite core in which a plurality of silicon steel strips are joined, and it is preferable to disassemble the respective silicon steel strips. In addition, as the winding 12, copper wire, formal flat copper wire, ground flat copper wire, electrodeposited flat copper wire, cross conductor, copper strip, etc. are used. For example, when a ground wire flat copper wire is used as the winding 12, a flat wire It is preferable to further dismantle the copper wire part and the winding part, and when a cross conductor is used, it is preferable to further disassemble it with a flat copper wire and an external insulator. Similarly, the tap changer device 14 is disassembled so as to be a minimum unit of components such as a tab plate and a tap changer. In this way, disassembling the transformer and classifying it by component means disassembling it until it becomes the smallest unit that forms the component or the smallest possible unit. In this specification, the word component includes the meaning of a component of a minimum unit obtained by further disassembling components of a transformer.

With respect to at least some of the components obtained by dismantling the cleaned transformer as described above, an inspection for measuring the remaining amount of the PCB or the like may be performed. The inspection may be performed on at least some of the components obtained by dismantling the cleaned transformer, but in particular, it is preferable to perform the inspection on the iron core or winding in which the PCB, etc., among the components, is easy to remain and is difficult to come into contact with the cleaning agent. The remaining amount of PCB in the component can be measured, for example, by the method prescribed in the 'Waste Treatment and Cleaning Act'. In the case where the remaining PCB or the like is not detected in the component, the component obtained by dismantling can be reused or discarded as it is.

Conversely, when the PCB or the like is detected in a part of the component by inspection, it is preferable to re-clean the component by spraying a cleaning agent on the component. When a PCB or the like is detected in some of the components, the cleaning agent may be sprayed only on the detected components, and the cleaning agent may be sprayed on all of the components obtained by disassembly to perform re-cleaning. The detergent sprayed in the re-cleaning process is a hydrocarbon-based solvent or a halogen-based solvent that can be used for cleaning. For example, an alkane, alkene, cycloalkane or cycloalkene solvent having 8 to 15 carbon atoms (especially an alkane or alkene solvent having 11 to 13 carbon atoms) or a halogen solvent having 1 to 12 carbon atoms can be used. have. Specifically, hydrocarbon solvents such as Aqua Solvent G71 (Aqua Chemical Co., Ltd.), HC-370 (Toso Co., Ltd.), MD-250 (Musashi Techno Chemical Co., Ltd.), Linpar12 (Sasol Limited), MACSOL-P (NSI Co., Ltd.) A commercially available solvent containing dodecane as a main component can be used. In other cases, it is also possible to use water, a water-based solvent, alcohol, or the like. It is particularly preferable to use the same cleaning agent as the cleaning agent used in the cleaning step also in the re-cleaning step. After the re-cleaning process, the re-cleaned components may be re-inspected to see if PCBs or the like are detected. In this way, by repeating the inspection process and the re-cleaning process several times as needed, it is possible to obtain a component that has completely washed the PCB and the like. The various components that have been thoroughly cleaned of the PCB can be recycled or disposed of as waste.

Additionally, an implementation of the cleaning method of an embodiment is described with reference to FIG. 1 . As shown in FIG. 1 in the transformer 10 with the inside of the contaminated flow path containing PCB, etc. contaminated, the coolers 51 and 52 and the chillers 61 and 62, the demister 7, the vacuum pump 81, the drain separator ( 82), the liquid feed pump 83, the detergent storage container 32, and the activated carbon tower 9 are respectively connected. The cleaning agent is introduced into the liquid storage container 31 disposed on the lower inner side of the vaporized cleaning tank 1 . The vaporization cleaning tank 1 is closed, the on/off valves 202 and 203 are opened, and the on/off valves 201 and 204 are closed to operate the vacuum pump 81 to depressurize the inside of the vaporization cleaning tank 1 . At this time, the exhaust of the vacuum pump 81 is discharged to the outside of the system through the on/off valve 203 and the activated carbon tower 9 . In this state, the heating device 4 is operated. At this time, the vacuum pump 81 is also operated. The cleaning agent introduced into the evaporative cleaning tank 1 starts to evaporate, and immediately when the temperature inside the evaporative cleaning tank 1 reaches more than the boiling point of the cleaning agent, the evaporative cleaning agent diffuses into the evaporative cleaning tank 1 . At this time, when the operation is stable, the on-off valve 204 is opened and the on-off valve 203 is closed to further liquefy the exhaust of the vacuum pump 81 by the cooler 52 to the vaporization cleaning tank 1 . By returning the exhaust gas to the outside of the system, the system can be closed. A cooler 51 is connected to the vaporized cleaning tank 1 , and the vaporized cleaning agent discharged to the outside of the vaporized cleaning tank 1 returns to a liquid by the cooler 51 , and temporarily stays in the cleaning agent storage container 32 . The vaporized cleaning agent that has not been liquefied by the cooler (51) becomes a liquid by the demister (7). By continuing heating and depressurization as it is, the vaporized cleaning agent penetrates to between the components of the transformer 10 disposed inside the vaporized cleaning tank 1, and is replaced while repeating condensation and turning, and dissolving or dispersing the contaminated oil containing PCBs, etc. make it Preferably, here, by slightly weakening the operation of the vacuum pump 81 and optionally supplying an inert gas to the inside of the evaporative washing tub 1, the pressure in the evaporative washing tub 1 is increased, and at the same time the on-off valve 202 is opened, and by operating the liquid feeding pump 83, the liquid detergent remaining in the detergent storage container 32 is sprayed into the transformer 10 disposed in the evaporative cleaning tank 1 through the pipe. Since the vaporized cleaning agent is liquefied at once due to the fluctuation of the pressure inside the vaporized cleaning tank 1 and the liquid cleaning agent sprayed to the location having a reduced volume is sucked, the cleaned cleaning agent and the normal cleaning agent are exchanged instantaneously. At this time, the cleaning agent that has been cleaned is physically washed down by the sprayed liquid cleaning agent and is dropped to the lower part of the evaporative cleaning tank 1 . Thereafter, the liquid feeding pump 83 is stopped, the on/off valve 202 is closed to restore the operation of the vacuum pump 81 to its original state, and the cleaning operation is continued again. In this way, the liquid detergent remaining in the detergent storage container 32 is transferred to the inside of the transformer 10 while periodically changing the pressure in the vaporized washing tank 1 by refluxing the vaporized detergent for a predetermined time into the vaporized washing tank 1 The inside of the transformer 10 is cleaned while spraying. At this time, the on-off valve 201 is opened and the on-off valve 202 is closed so that the liquid detergent remaining in the detergent storage container 32 is returned directly to the vaporization cleaning tank 1 without spraying it into the transformer 10 . By doing so, it is also possible to adjust the timing and amount of injection into the transformer 10 . After the cleaning operation is finished, the heating device 4 and the vacuum pump 81 are stopped, and the vaporization cleaning tank 1 is cooled. The washing-completed detergent and the liquid detergent in which the vaporized detergent liquefied fall and remain in the vaporized washing tank 1 bottom. When the temperature inside the vaporized cleaning tank (1) is lowered and the vaporized cleaning agent is liquefied, the on/off valves (201, 203) are opened to vaporize and wash the contaminated cleaning agent remaining in the liquid storage container (31) under the vaporized cleaning tank (1). It is discharged and recovered to the outside of the purification tank (1) (not shown). At this time, the inert gas may be flushed into the evaporative cleaning tank 1 from a tank for supplying an inert gas (not shown), and the cleaning agent may be pushed out of the evaporative cleaning tank 1 . In addition, in some cases, the liquefied detergent is discharged to the outside of the vaporization washing tank 1 in a state where the internal temperature of the vaporization washing tank 1 has not gone down. On the other hand, an inert gas can be supplied into the evaporative cleaning tank 1 from an inert gas supply tank (not shown), and the cleaning liquid remaining inside the transformer 10 can be dried. If the cleaning operation according to the embodiment of the present invention is normally performed once, it is possible to completely clean the transformer 10 contaminated with the contaminated oil containing PCB, etc. disposed inside the vaporization cleaning tank 1 . The cleaning operation according to the embodiment of the present invention may be repeated a plurality of times as necessary to completely clean the transformer contaminated with the contaminated oil containing PCB, etc. disposed inside the vaporization cleaning tank 1 .

2 is a system according to the prior art described in Patent Document 2. In FIG. 2, reference numeral 1 denotes a evaporative cleaning tank, 33 a cleaning agent recovery container, 4 a heating device, 51 and 52 a cooler, 61 and 62 a chiller, 7 a demister, 81 a vacuum pump, 82 a drain separator, 9 an active It is a carbon tower, and 201, 202, 203, and 204 are opening/closing valves for opening and closing the flow passages installed in the cleaning agent flow path and the pressure reducing flow path. By opening and closing these opening/closing valves, the pressure of the system can be adjusted, and the cleaning agent can be introduced and discharged. Alternatively, in FIG. 2 , two transformers 10 , which are objects to be cleaned, are disposed in the evaporative cleaning tank 1 .

1 evaporative washing tank
101 container
102 partition plate
10 transformer
11 iron core
12 winding
14 tap changer
15 Insulation loss
20 system container
31 liquid reservoir
32 detergent storage container
33 detergent recovery container
4 heating device
51, 52 cooler
61, 62 chillers
7 Demister
81 vacuum pump
82 drain separator
83 liquid feed pump
9 Activated Carbon Tower
201, 202, 203, 204 on/off valve

Claims (3)

A cleaning system for cleaning a transformer, comprising at least a vaporization cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device,
A transformer contaminated with polychlorinated biphenyl is placed inside the evaporative washing tank, a cleaning agent is supplied to the inside of the evaporative washing tank, the inside of the evaporative washing tank is set to a pressure lower than atmospheric pressure, and the evaporative washing tank is heated After vaporizing the cleaning agent and cleaning the transformer with the vaporized cleaning agent, the vaporized cleaning agent is liquefied by the cooler and the liquefaction device, and the liquefied cleaning agent is temporarily stored in the cleaning agent storage container, and the The cleaning system for cleaning the transformer in a closed or semi-closed system, characterized in that the temporarily stored cleaning agent is refluxed into the transformer disposed inside the vaporization cleaning tank using the liquid feeding pump. Polychlorinated biphenyl using a cleaning system for cleaning a transformer, including at least a vaporized cleaning tank, a heating device, a cooler, a cleaning agent storage container connected to the cooler, a liquid feeding pump connected to the cleaning agent storage container, a liquefaction device, and a pressure reducing device A method for cleaning a contaminated transformer in a closed or semi-closed system, comprising the following steps:
disposing the transformer inside the evaporative washing tank,
Supplying a cleaning agent to the inside of the evaporative cleaning tank,
to a pressure lower than atmospheric pressure inside the vaporization washing tank,
Heating the evaporative washing tank to raise the temperature inside the evaporative washing tub to above the boiling point of the detergent to vaporize the washing agent inside the evaporative washing tub;
cleaning the transformer with the vaporized cleaning agent,
The vaporized cleaning agent is liquefied by the cooler and the liquefaction device, the liquefied cleaning agent is temporarily stored in the cleaning agent storage container, and the temporarily stored cleaning agent is placed inside the vaporized cleaning tank using the liquid feeding pump A method of cleaning the transformer, comprising refluxing into the transformed transformer. 3. The method of claim 2,
The method of cleaning a transformer, further comprising the step of liquefying the vaporized cleaning agent and discharging the liquefied cleaning agent to the outside of the vaporized cleaning tank.

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