Description

APPARATUS AND METHOD AND FOR TREATMENT OF

WASTE INSULATING OIL

Technical Field

[1] The present invention relates to a method of decomposing and treating waste insulating oil containing poly chlorinated biphenyl (PCBs) without harm from an environmental point of view and a treatment apparatus for decontaminating waste insulating oil containing PCBs, that is, persistent organic pollutants at the storage place. Background Art

[2] Polychlorinated biphenyl has been used for multi-purposes such as insulating oil, heating medium, lubricating oil, and plastic and are therefore of very high utility value. Further, polychlorinated biphenyl has been used in various uses since it is nonflammable, no concern about heat denaturation and very stable chemically and also has an excellent insulating or electrical characteristic.

[3] Polychlorinated biphenyl is basically a compound in which hydrogen combined at ten hydrogen atom positions of biphenyl (C6H5-C6H5) is substituted with 1 to 10 chlorine atoms and may have 242 kinds of isomers theoretically, but about 100 kinds of them are used actually. Polychlorinated biphenyl is not decomposed by heat, insoluble in water and excellent in the electrical insulating property and has therefore been used for electric products such as a transformer and a condenser.

[4] Polychlorinated biphenyl is induced in the sewage disposal plant without change after use, causing environmental destruction and a change in ecosystem. This polychlorinated biphenyl had been used without special measures from an environmental viewpoint and been found as gradually serious pollutants. Thus, the production and use of polychlorinated biphenyl was stopped worldwide including Japan since 1976. However, a million ton of polychlorinated biphenyl had already been discharged all over the world and the amount of polychlorinated biphenyl that should be wasted and disposed has reached two million tones. It has been known that Korea has a great quantity of polychlorinated biphenyl that should be disposed. Accordingly, there is an urgent need for an efficient decomposition method.

[5] In accordance with US Environment Protection Agency (EPA), it has been reported that there are 90 or more kinds of technologies that can treat polychlorinated biphenyl. It has been known that technologies for treating harmful chemicals such as polychlorinated biphenyl largely include a biochemical treatment technology, a physical-chemical treatment technology, a thermal treatment technology, a treatment

technology by irradiating an e-beam and so on.

[6] Biochemical treatment using enzyme, etc., which is effective in the polychlorinated biphenyl treatment, this treatment method is advantageous in that it is applicable to various media polluted with polychlorinated biphenyl and has a minimum persistent pollutants created, but is disadvantageous in that it requires a long treatment time and has the treatment efficiency greatly influenced by the polychlorinated biphenyl concentration.

[7] The thermal treatment technology is advantageous in that it has a fast treatment speed and a small volume of treated waste, but is disadvantageous in that it is limited to the application to liquid-gaseous media and requires relatively high expenses and an additional treatment of persistent pollutants created after treatment. Further, in the case in which products including polychlorinated biphenyl are incinerated using general methods, it has been reported that poly cyclic aromatic hydrocarbons and so on, which include dioxin having toxicity stronger than polychlorinated biphenyl, are created as byproducts. Accordingly, this incineration method has limits to a safe treatment of waste insulating oil including polychlorinated biphenyl. In particular, as it is known that noxious dioxin, etc. are created and discharged by this incineration method, products including polychlorinated biphenyl are usually exported overseas and treated and stored for a long period of time due to a strong opposition of residents who live in an area where an incineration plant is installed. In the case in which products including polychlorinated biphenyl are stored for a long period of time, polychlorinated biphenyl is discharged from waste containing polychlorinated biphenyl into the environment, which increases a danger of pollution in surrounding environments.

[8] A decomposition method using ultraviolet rays is disadvantageous in that it has low decomposition efficiency. A chemical decomposition method using an oxidant can decompose polychlorinated biphenyl in several hours, but is problematic in corrosion of an apparatus material due to use of the oxidant. A supercritical oxidization decomposition method has a problem that energy consumption is excessively great.

[9] The chemical treatment technology is disadvantageous in that it requires an additional treatment of persistent pollutants created after treatment in the same manner as the thermal treatment technology, but is advantageous in that it has a fast treatment speed, can be applied to various media polluted with polychlorinated biphenyl, enables the treatment of a high-concentration polychlorinated biphenyl, and can be utilized as a recuperative technology. Chemical decomposition reactions of commercialized polychlorinated biphenyl include a sodium metal dispersing method (the northern island of Japan), a dechlorination decomposition method (Toyota, Japan), an alkaline-catalyzed decomposition method (US, Japan, Australia), a catalytic hydro-dechlorination reaction method (Osaka of Japan), a dechlorination decomposition method (Kyushu of

Japan, Canada), a water heat oxidization decomposition method (Tokyo of Japan), an organic metal alkaline decomposition method (Japan), a chemical extraction decomposition method (Japan), a supercritical oxidization method (US, Japan) and so on.

[10] Further, Japanese Unexamined Patent Application Publication No. 1999-316798 discloses a method of treating polychlorinated biphenyl contained in insulating oil by adding ethyl alcohol, ethylene glycol, and an alkaline hydroxide to the insulating oil containing polychlorinated biphenyl and irradiating ultraviolet rays to the polychlorinated biphenyl for dechlorination. Japanese Unexamined Patent Application Publication No. 2001-29942 discloses a method of treating polychlorinated biphenyl containing insulating oil using titanium oxide as a photocatalyst.

[11] There is a method of disposing polychlorinated biphenyl included in insulating oil by irradiating an e-beam. This method is disadvantageous in that it requires an expensive installation apparatus and must treat chlorine molecules again because there is a possibility that chlorine molecules may remain in insulating oil.

[12] In the treatment process of a Japan company using the sodium metal dispersing method as a chemical dechlorination decomposition reaction, a large building of about 24000m in plottage is used in order to treat about 0.5 ton of insulating oil including polychlorinated biphenyl a day. Insulating oil is extracted from a transformer as a pre- treatment process, and a vacuum heating segregation process is performed in order to remove polychlorinated biphenyl, attached to the transformer, from the transformer. The transformer is crushed, a process of cleaning transformer members is carried out, and a process of treating polychlorinated biphenyl by applying sodium metal to the insulating oil in a reaction furnace is then carried out. This method is disadvantageous in that it requires a factory with a large plottage because the pre-treatment process is complicated.

[13] Further, in the process of performing the sodium dispersing method in the reaction furnace, a contact probability between a dechlorination reagent and polychlorinated biphenyl molecules is increased by dispersing heat. Thus, an attempt is made to increase a reaction probability between the reagent molecules and the polychlorinated biphenyl molecules by raising temperature. For this reason, problems arise because lots of energy is consumed in the reaction furnace and treatment expenses rise since a high reaction temperature (160 to 170 degrees Celsius) is maintained. Disclosure of Invention Technical Problem

[14] The present invention has been made to remove the problems in the treatment process of the conventional sodium metal dispersing method and provides a new process of a polychlorinated biphenyl chemical decomposition treatment method.

[15] In the conventional sodium metal dispersing method using a chemical dechlorination reaction, a solvent cleaning apparatus and a vacuum heating segregation equipment treatment process are required in order to remove poly chlorinated biphenyl remaining in the transformer, etc. However, an object of the present invention is to provide a treatment method and apparatus for rapidly disposing polychlorinated biphenyl within waste insulating oil containing polychlorinated biphenyl without the above treatment processes and decomposing polychlorinated biphenyl remaining in members (a container, iron core kinds, paper or wood kinds, etc.) within a transformer. Further, the present invention provides a movable type treatment apparatus that can be used in an area of a degree that it can be installed on even a vehicle by using a simplified treatment process without a large treatment factory plottage.

[16] Further, in the conventional process of performing the sodium dispersing method in the reaction furnace, a contact probability between a dechlorination reagent and molecules of polychlorinated biphenyl is enhanced through thermal dispersion in order to improve a reaction probability between the dechlorination reagent and the polychlorinated biphenyl molecules by raising temperature. Accordingly, a high reaction temperature (160 to 170 degrees Celsius) has to be maintained as possible. Consequently, there are problems in that lots of energy is consumed in the reaction furnace and the expenses at the time of treatment are increased. The present invention has improved the above problems and provides a method of sufficiently generating a desired reaction even at a low temperature of about 130 degrees Celsius by increasing the contact probability between the dechlorination reagent components and the polychlorinated biphenyl molecules within waste insulating oil through not only thermal dispersion, but also physical dispersion.

[17] The objects of the present invention are not limited to the above-mentioned objects and other objects that have not been mentioned above will become evident to those skilled in the art from the following description. Technical Solution

[18] To accomplish the above objects, an apparatus and method for treating waste insulating oil including polychlorinated biphenyl in accordance with the present invention includes a controller for controlling an overall operation of the treatment apparatus, a reaction container in which the waste insulating oil including polychlorinated biphenyl chemically reacts to sodium metal, that is, a reagent, a high-speed motor, a rotary shaft, and stirring vanes for generating eddy flow in the waste insulating oil including the reagent within the reaction container, a temperature control heating unit for generating a reaction between the waste insulating oil and the reagent within the reaction container, a temperature sensor for sensing a temperature of the

waste insulating oil within the reaction container, a level sensor for sensing a level of the waste insulating oil, and inflow and outflow pumps and a hose for introducing and draining the waste insulating oil to the reaction container and a transformer.

[19] To accomplish the above objects, an apparatus for treating waste insulating oil in accordance with an embodiment of the present invention includes a reaction container in which waste insulating oil containing polychlorinated biphenyl chemically reacts to a dechlorination reagent, a reagent supply unit for supplying the dechlorination reagent to the reaction container, a stirring vane provided within the reaction container and generating eddy flow in the waste insulating oil, and a heating unit provided within the reaction container and heating the waste insulating oil.

[20] To accomplish the above objects, a method of treating waste insulating oil in accordance with another embodiment of the present invention includes a pre-treatment tank for heating waste insulating oil extracted from waste, a reaction container in which the waste insulating oil heated in the pre-treatment tank chemically reacts to a dechlorination reagent, and a drain pump for draining the waste insulating oil of a high temperature, which has completed the chemical reaction in the reaction container, to the waste from which the waste insulating oil has been extracted.

[21] To accomplish the above objects, an apparatus for treating waste insulating oil in accordance with still another embodiment of the present invention includes an auxiliary container for accommodating waste and having waste insulating oil chemically react to a dechlorination reagent, stirring vanes provided within the auxiliary container and generating eddy flow in the waste insulating oil, and a heating unit provided within the auxiliary container and heating the waste insulating oil.

[22] To accomplish the above objects, a method of treating waste insulating oil in accordance with an embodiment of the present invention includes (a) introducing waste insulating oil within waste to a reaction container, (b) heating the waste insulating oil introduced to the reaction container, (c) dispersing a dechlorination reagent in the heated waste insulating oil, and (d) stirring and heating the waste insulating oil so that the waste insulating oil and the dechlorination reagent react to each other.

[23] The details of other embodiments are included in the detailed description and drawings.

Advantageous Effects

[24] The apparatus and method for treating waste insulating oil according to the present invention have one or more of the following advantages. [25] First, the conventional sodium metal dispersing method using a chemical dechlorination reaction required the solvent cleaning apparatus and the vacuum heating

segregation apparatus treatment process in the transformer, etc. The treatment apparatus and method of the present invention is advantageous in that it can decontaminate polychlorinated biphenyl remaining in members within a transformer without the conventional solvent cleaning apparatus and vacuum heating segregation apparatus treatment process in such a way that polychlorinated biphenyl is dissoluted by electrically heating a transformer iron core and a core in order to rapidly dispose the polychlorinated biphenyl through a chemical reaction between the polychlorinated biphenyl and sodium metal atoms within insulating oil. Further, the conventional treatment method and apparatus for decomposing polychlorinated biphenyl within members of a transformer (a container, iron core kinds, paper or wood kinds, etc.) must clean the transformer members through crushing. However, the treatment method and apparatus of the present invention is advantageous in that an additional expensive crushing apparatus is not necessary since polychlorinated biphenyl is rapidly disposed through a chemical reaction with sodium metal atoms within insulating oil by electrically heating the transformer iron core and the core so as to dissolute the polychlorinated biphenyl. Accordingly, through this treatment process, a movable type treatment apparatus, which can treat polychlorinated biphenyl within insulating oil even at an area of a degree that the apparatus can be installed on even a vehicle without a large treatment factory plottage, can be provided. Accordingly, the present invention is advantageous in that it can decontaminate polychlorinated biphenyl cheaply and conveniently.

[26] Second, the existing sodium metal dispersing method increases a contact probability between a dechlorination reagent and molecules of polyvinyl chloride through thermal dispersion in view of process. Accordingly, a reaction probability between reagent molecules and the polychlorinated biphenyl molecules must be enhanced by raising temperature. To this end, a high reaction temperature (160 to 170 degrees Celsius) has to be maintained as possible. This results in problems that lots of energy is consumed in the reaction furnace and the expenses at the time of treatment are increased. The present invention has improved the above problems and is advantageous in that it can sufficiently generate a rapid reaction even at a low reaction temperature of about 130 degrees Celsius by increasing the contact probability between the dechlorination reagent components and the polychlorinated biphenyl molecules within waste insulating oil through not only thermal dispersion, but also physical dispersion.

[27] Third, the conventional sodium metal dispersing method is problematic in that it consumes lots of energy in a reaction furnace and increases the expenses at the time of treatment since a high reaction temperature (160 to 170 degrees Celsius) is maintained. The present invention has improved the above problem and is advantageous in that it can decontaminate polychlorinated biphenyl within insulating oil economically by suf-

ficiently generating a desired chemical reaction even at a low reaction temperature of about 130 degrees Celsius by increasing the contact probability between the dechlorination reagent components and the polychlorinated biphenyl molecules within waste insulating oil through not only thermal dispersion, but also physical dispersion.

[28] Fourth, a stirring vane is installed between a heater pipe bundle having a plurality of heater pipes, and the stirring vane is rotated at high speed. Accordingly, the present invention is advantageous in that it can accelerate physical dispersion of insulating oil and sodium and can directly transfer heat of the heater pipe bundle to insulating oil rapidly.

[29] Fifth, insulating oil is dehydrated and preheated in the pre-treatment tank and polychlorinated biphenyl remaining in transformer members is treated in the post-treatment tank, while treating the insulating oil in the reaction container. Accordingly, the present invention is advantageous in that it can increase the treatment efficiency of insulating oil.

[30] Sixth, polychlorinated biphenyl remaining in transformer members is treated additionally by directly injecting insulating oil of a high temperature, which has been treated in the reaction container and has sodium dispersed therein, to the transformer. Accordingly, the present invention is advantageous in that it can improve the treatment efficiency.

[31] The advantages of the present invention are not limited to the above advantages and other advantages that have not been mentioned above will become evident to those skilled in the art from the claims. Brief Description of the Drawings

[32] Fig. 1 shows the construction of an apparatus for treating waste insulating oil in accordance with an embodiment of the present invention;

[33] Fig. 2 is a view showing that the waste insulating oil treatment apparatus in accordance with an embodiment of the present invention is mounted in a vehicle;

[34] Fig. 3 shows the construction of an apparatus for treating waste insulating oil in accordance with another embodiment of the present invention;

[35] Fig. 4 shows the construction of an apparatus for treating waste insulating oil in accordance with still another embodiment of the present invention; and

[36] Fig. 5 shows the construction of an apparatus for treating waste insulating oil in accordance with further another embodiment of the present invention. Best Mode for Carrying Out the Invention

[37] Merits and characteristics of the invention, and methods for accomplishing them will become more apparent from the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the disclosed

embodiments, but may be implemented in various manners. The embodiments are provided to complete the disclosure of the present invention and to allow those having ordinary skill in the art to understand the scope of the present invention. The present invention is defined by the category of the claims. The same reference numbers will be used throughout the drawings to refer to the same or like parts.

[38] Hereinafter, the present invention is described in connection with embodiments of the present invention with reference to the drawings for illustrating the apparatus and method for treating waste insulating oil. It is hereinafter described that waste including waste insulating oil include a transformer as an example, but can include a condenser, a cutout, a circuit breaker and so on as well as the transformer according to an embodiment.

[39] FIG. 1 shows the construction of an apparatus for treating waste insulating oil in accordance with an embodiment of the present invention.

[40] A motor 10 rotates a rotary shaft 90. The rotary shaft 90 is provided within a reaction container 15 and is rotatably coupled to the motor 10. A stirring vane 100 is provided in the rotary shaft 90 and rotated therewith, and therefore distributes and rotates waste insulating oil and a dechlorination reagent of the reaction container 15 physically and mutually, thereby increasing a physical contact probability between the waste insulating oil and the dechlorination reagent and accelerating a reaction thereof. A level sensor 20 senses whether the waste insulating oil, which will be treated in the reaction container 15, has reached the highest level.

[41] A heating unit 30 heats the waste insulating oil within the reaction container 15 up to a reaction temperature. A temperature sensor 40 senses a reaction temperature within the reaction container 15. A controller 50 controls the entire operation of the waste insulating oil treatment apparatus. A power source unit 60 supplies power source to the waste insulating oil treatment apparatus.

[42] A drain pump 70 drains the waste insulating oil of a high temperature, which exists in the reaction container 15, to a transformer 160. An inflow pump 80 introduces the waste insulating oil within the transformer 160 to the reaction container 15.

[43] A reagent supply unit 110 supplies a dechlorination reagent to the reaction container

15. An inflow/outflow hose 120 is coupled between the reaction container 15 and the transformer 160 and has the waste insulating oil pass therethrough. The inflow/outflow hose 120 is made of material, which can withstand up to a high temperature of 200 degrees Celsius such that the waste insulating oil of a high temperature can pass through the inflow/outflow hose 120. A transformer level sensor 130 is attached to the end of the inflow/outflow hose 120 and senses a level of the waste insulating oil within the transformer 160. A transformer temperature sensor 140 senses a temperature of the waste insulating oil within the transformer 160. A nozzle 150 is a nozzle through

which the waste insulating oil is input to or output from the transformer 160.

[44] Fig. 2 is a view showing that the waste insulating oil treatment apparatus in accordance with an embodiment of the present invention is mounted in a vehicle.

[45] A vehicle 200 has mounted therein the waste insulating oil treatment apparatus in accordance with an embodiment of the present invention. A control console 210 is a control panel for operating the waste insulating oil treatment apparatus and is controlled by an operator. A controller 220 is an electronic controller for controlling the waste insulating oil treatment apparatus of the present invention. A container 230 accommodates the waste insulating oil treatment apparatus and protects the apparatus. A reaction container 240 performs a reaction treatment on polychlorinated biphenyl within waste insulating oil. An inflow/outflow hose 250 drains or introduces the waste insulating oil to or from a transformer 260. The transformer 260 is waste in which waste insulating oil containing polychlorinated biphenyl has been used.

[46] Fig. 3 shows the construction of an apparatus for treating waste insulating oil in accordance with another embodiment of the present invention.

[47] Waste insulating oil containing polychlorinated biphenyl chemically reacts to a dechlorination reagent in a reaction container 310. The reaction container 310 is a space in which waste insulating oil is introduced and a dechlorination reagent is supplied from a reagent supply unit 320 and a chemical reaction occurs between the waste insulating oil and the dechlorination reagent. The reaction container 310 has a stirring vane 330 and a heating unit 340 equipped therein.

[48] The reagent supply unit 320 supplies the dechlorination reagent to the reaction container 310. The reagent supply unit 320 stores the dechlorination reagent and supplies the dechlorination reagent when the waste insulating oil is introduced to the reaction container 310. The dechlorination reagent can include a variety of reagents, and sodium metal is preferably used.

[49] The stirring vane 330 is provided within the reaction container 310 and generates eddy flow in the waste insulating oil. A plurality of the stirring vanes 330 is preferably provided and they have their center preferably coupled by a rotary shaft 350. When the rotary shaft 350 is rotated by a driver 360, the stirring vanes 330 are rotated to thereby accelerate physical dispersion of the waste insulating oil and the dechlorination reagent. It is preferred that a heating unit 340 be provided between the plurality of stirring vanes 330.

[50] The heating unit 340 is provided within the reaction container 310 and heats the waste insulating oil. The heating unit 340 is preferably provided between the plurality of stirring vanes 330. The heating unit 340 can be implemented in various ways and is preferably implemented as a bundle having a plurality of heater pipes. The heating unit 340 preferably heats the waste insulating oil at a temperature of about 130 degrees

Celsius.

[51] The above waste insulating oil treatment apparatus can be implemented in such a way to be mounted in a vehicle, as shown in Fig. 2.

[52] Fig. 4 shows the construction of an apparatus for treating waste insulating oil in accordance with still another embodiment of the present invention.

[53] A pre-treatment tank 401 heats waste insulating oil extracted from a transformer 402.

The pre-treatment tank 401 stores the waste insulating oil introduced from the transformer 402 via an inflow pump 403. Pre-treatment tank stirring vanes 404, which are rotated, and a pre-treatment tank heating unit 405, which are provided between the pre-treatment tank stirring vanes, are preferably provided within the pre-treatment tank 401. The pre-treatment tank heating unit 405 heats the waste insulating oil at a temperature of about 100 degrees Celsius and removes moisture from the waste insulating oil. Further, the pre-treatment tank heating unit 405 preheats the waste insulating oil, thus shortening a treatment time. The waste insulating oil heated in the pre-treatment tank 401 is transferred to a reaction container 407 by a first feed pump 406.

[54] The waste insulating oil, which has been heated in the pre-treatment tank 401 and delivered therefrom, chemically reacts to a dechlorination reagent in the reaction container 407. A reagent supply unit 408, stirring vanes 409, and a heating unit 410 can be provided within the reaction container 407, as shown in Fig. 1 or 3. The waste insulating oil of a high temperature whose chemical reaction has been completed in the reaction container 407 is transferred to a post- treatment tank 412 by a second feed pump 411.

[55] The post-treatment tank 412 stores the waste insulating oil of a high temperature, which has been feed from the reaction container 407 by the second feed pump 411. The waste insulating oil of a high temperature, which has been stored in the post- treatment tank 412, is directly drained to an empty transformer 414 from which waste insulating oil has been extracted through a drain pump 413.

[56] The drain pump 413 drains the waste insulating oil of a high temperature, which has been stored in the post- treatment tank 412, to the empty transformer 414 from which waste insulating oil has been extracted. The drain pump 413 drains the waste insulating oil of a high temperature to the empty transformer 414 so that poly chlorinated biphenyl remaining in the empty transformer 414 is treated.

[57] The above waste insulating oil treatment apparatus can be mounted in a vehicle as a movable type, as shown in Fig. 2.

[58] Fig. 5 shows the construction of an apparatus for treating waste insulating oil in accordance with further another embodiment of the present invention.

[59] An auxiliary container 510 accommodates a transformer 520. Waste insulating oil

chemically reacts to a dechlorination reagent in the auxiliary container 510. The auxiliary container 510 accommodates the transformer 520 and treats poly chlorinated biphenyl remaining in the transformer through waste insulating oil stored in the auxiliary container. An auxiliary stirring vane 530 and an auxiliary heating unit 540 are preferably provided within the auxiliary container 510. It is also preferred that a temperature sensor 550 be provided within the auxiliary container 510 and sense a temperature of the waste insulating oil. According to an embodiment, in the case in which waste insulating oil is directly filled in the transformer 520 without the auxiliary container 510, the auxiliary stirring vane 530, the auxiliary heating unit 540, the temperature sensor 550 or the like may be provided within the transformer.

[60] A power source unit 560 supplies AC power to the primary coil of the transformer

520, and a short circuit 570 shorts the secondary coil of the transformer. When the power source unit 560 supplies power source to the primary coil and the short circuit 570 shorts the secondary coil, a core 580 within the transformer is heated. When the core 580 within the transformer is heated, poly chlorinated biphenyl remaining in a coil, insulating paper, etc. within the core is dissoluted as waste insulating oil and chemically reacts to a dechlorination reagent.

[61] The power source unit 560 may also supply DC power to the primary and secondary coils of the transformer 520. In this case, the short circuit 570 is omitted.

[62] In the present embodiment, it has been described that the auxiliary container 510 is used. However, after waste insulating oil is drained to the transformer 520 without the auxiliary container, persistent polychlorinated biphenyl may be treated by supplying AC power the primary coil and shorting the secondary coil or persistent polychlorinated biphenyl may be treated by supplying DC power to the primary coil and the secondary coil.

[63] The above-mentioned waste insulating oil treatment apparatus can be independently constructed and implemented and may be constructed and implemented as a part of the waste insulating oil treatment apparatus shown in Fig. 1 or 4.

[64] Further, the above-mentioned waste insulating oil treatment apparatus may be mounted in a vehicle as a movable type, as shown in Fig. 2.

[65] An operation of the waste insulating oil treatment apparatus constructed as above in accordance with the present invention is described below.

[66] Referring to Fig. 1, when power source is supplied to a power source unit 60, the controller 50 resets the waste insulating oil treatment apparatus of the present invention and receives a reset state of the waste insulating oil treatment apparatus from each sensor.

[67] In the case in which the waste insulating oil treatment apparatus has been actuated, the controller 50 resets each part of the waste insulating oil treatment apparatus. The

controller 50 turns off power source to the heating unit 30 and stops the operation of the driver 10, the inflow pump 80, and the drain pump 70. The controller 50 checks a temperature of the reaction container 15 through the temperature sensor 40, determines whether waste insulating oil is contained in the reaction container through the level sensor 20, and displays a current state on a control console 55 attached to the controller 50.

[68] The controller 50 controls the transformer temperature sensor 140 and the transformer level sensor 130, which are attached to the nozzle 150 disposed within the transformer 160, to sense a temperature and level of the waste insulating oil contained in the transformer and controls the control console 55 to display the results. In the state where the supply of electric power to a connecting wire 180, which is connected from the controller 50 to a core 170 of the transformer 160, is blocked, the waste insulating oil treatment apparatus is fully reset and then in an operation standby state.

[69] When the nozzle 150 is mounted in the inlet of the transformer 160 in which waste insulating oil including polychlorinated biphenyl is contained after the reset operation is completed, the transformer level sensor 130 and the transformer temperature sensor 140 is impregnated in the waste insulating oil within the transformer 160. When an operation button of the control console 55 is pressed, the controller 50 starts an operation in which the waste insulating oil treatment apparatus treats the waste insulating oil including polychlorinated biphenyl. The controller 50 drives the inflow pump 80 to introduce the waste insulating oil within the transformer 160 to the reaction container 15 through the nozzle 150 and the inflow/outflow hose 120. The introduced waste insulating oil reaches the highest level of the reaction container 15 so that the air does not remain at an inner upper portion of the reaction container 15.

[70] The level sensor 20 senses whether the waste insulating oil has reached the highest level of the reaction container 15. When the controller 50 receives the highest level signal sensed by the level sensor 20, the controller 50 stops the operation of the inflow pump 80. The reagent supply unit 110 supplies a predetermined amount of sodium metal to the reaction container 15. The controller 50 supplies electric power to the heating unit 30 in order to raise a temperature of the waste insulating oil within the reaction container 15. The controller 50 controls the temperature sensor 40 to continuously sense a temperature of the waste insulating oil within the reaction container 15. When the temperature of the waste insulating oil is 100 degrees Celsius or less, the controller 50 slowly rotates the driver 10 at a low speed of a first step such that the waste insulating oil within the reaction container 15 has a uniform temperature in each part. When the temperature of the waste insulating oil within the reaction container 15 becomes 100 degrees Celsius or higher, sodium metal begins slowly being dispersed in the waste insulating oil.

[71] At this time, a chemical reaction occurs between chlorine atoms of polychlorinated biphenyl within the waste insulating oil and sodium metal atoms. A reaction equation is as follows.

[72] Ar . Cl + Na (metal) = Ar + NaCl

[73] Polychlorinated biphenyl, which is dispersed in the waste insulating oil to a small amount (several tens of PPM), and sodium metal are randomly moved by thermal dispersion, encounter each other, and then decomposed into harmless NaCl through a reaction between the chlorine atoms of polychlorinated biphenyl and the sodium metal atoms.

[74] When the temperature of the reaction container 15 ranges from 110 to 145 degrees

Celsius, the controller 50 rotates the driver 10 at high speed for a specific period of time in order to forcedly generate a strong eddy flow in the waste insulating oil by means of the stirring vanes, which are attached to the rotary shaft, as well as thermal dispersion, thereby maximizing a probability that sodium metal may encounter polychlorinated biphenyl and accelerating a chemical reaction. The driver 10 is driven for a specific period of time. Therefore, the rotary shaft 90, which is rotatably coupled to the driver, and the stirring vanes 100, which are attached to the rotary shaft and rotated within the waste insulating oil, and form a strong eddy flow in the waste insulating oil make polychlorinated biphenyl molecules of the waste insulating oil sufficiently react to sodium metal atoms, thereby changing them to sodium chloride. Consequently, the waste insulating oil from which the toxicity of polychlorinated biphenyl has been removed becomes harmless.

[75] Next, the controller 50 controls the drain pump 70 to drain the waste insulating oil of a high temperature from which polychlorinated biphenyl within the reaction container has been chemically treated to be harmless to the transformer 160. Here, the controller 50 checks whether the waste insulating oil, which has been drained through the transformer level sensor 130 attached to the nozzle 150, reaches the highest level of the transformer 160. If the waste insulating oil has reached the highest level, the controller 50 immediately stops the operation of the drain pump 70.

[76] Next, the controller 50 waits for a specific period of time and transfers heat of the waste insulating oil to the core 170 of the transformer 160 so that polychlorinated biphenyl infiltrated into non-impregnating members (a container, iron core kinds) and impregnating member (paper or wood kinds) within the core are dissoluted as the waste insulating oil within the transformer 160. Here, the chlorine atoms of polychlorinated biphenyl within the dissoluted members chemically react to sodium metal remaining in the waste insulating oil and thereby become harmless as sodium chloride.

[77] The controller 50 then dissolutes polychlorinated biphenyl, which has been infiltrated into the impregnating members, more strongly by applying electric power to the core

170 of the transformer 160 through the connecting wire 180 for a specific period of time. Preferably, AC power may be applied to the primary coil of the transformer 160 and the secondary coil is shorted, or DC power may be applied to the primary coil and the secondary coil. Polychlorinated biphenyl remaining in the impregnating and non- impregnating members of the inner container, the iron core, and the core within the transformer 160 is electrically heated and dissoluted, so that polychlorinated biphenyl chemically reacts to sodium metal remaining in the waste insulating oil and thus becomes harmless.

[78] Through the above treatment operation, chlorine atoms of polychlorinated biphenyl included in the waste insulating oil chemically reacts to sodium metal, has its toxicity removed and thus becomes harmless. In order to fully dissolute polychlorinated biphenyl remaining in the impregnating and non-impregnating members within the transformer 160 through a chemical reaction, the above treatment operation can be repeatedly performed 2 to 3 times.

[79] Further, the waste insulating oil of a high temperature immediately after the treatment remains contained in the transformer 160 so that polychlorinated biphenyl, which may have remained in the impregnating members within the transformer core 170, is dissoluted, continuously reacts to sodium metal remaining in the waste insulating oil, and thus becomes harmless. Next, a button to complete the operation of the control console 55 is pressed and the nozzle 150 is removed from the transformer. A transformer to be treated is input to waste insulating oil and the above harmless treatment process is then performed.

[80] Referring to Fig. 4, waste insulating oil within the transformer 402 is introduced to the pre-treatment tank 401 through the inflow pump 403. After the waste insulating oil is introduced to the pre-treatment tank 401, the pre-treatment tank stirring vanes 404 are rotated, and the heating unit 405 heats the waste insulating oil at a temperature of about 100 degrees Celsius in order to remove moisture from the waste insulating oil and preheat the waste insulating oil.

[81] The waste insulating oil from which moisture has been removed and that has been preheated is transferred to the reaction container 407 by the first feed pump 406. After the waste insulating oil is transferred to the reaction container 407, waste insulating oil of another transformer 415 is introduced to the pre-treatment tank 401 through the inflow pump 403.

[82] The waste insulating oil transferred to the reaction container 407 is treated as described above. Here, the waste insulating oil of the transformer 415, which has been introduced to the pre-treatment tank 401, is dehydrated and preheated. The waste insulating oil of a high temperature, which has been treated in the reaction container 407, is transferred to the post- treatment tank 412 through the second feed pump 411.

After the waste insulating oil is transferred to the post- treatment tank 412, the waste insulating oil of the transformer 415, which has been dehydrated and preheated in the pre-treatment tank 401, is transferred to the reaction container 407 through the first feed pump 406.

[83] The waste insulating oil of a high temperature, which has been transferred to the post- treatment tank 412, is immediately drained to the empty transformer 414 from which the waste insulating oil has been extracted through the drain pump 413. After the waste insulating oil of a high temperature is drained to the empty transformer 414, poly chlorinated biphenyl remaining in the empty transformer 414 is treated as described above. After the waste insulating oil of the post-treatment tank 412 is fully drained, the waste insulating oil of the transformer 415, which has completed a reaction in the reaction container 407, is transferred to the post- treatment tank 412 through the second feed pump 411. The waste insulating oil of a high temperature, which has been transferred to the post- treatment tank 412, is immediately drained to another empty transformer 416 from which waste insulating oil has been extracted through the drain pump 413.

[84] It will be understood that a person skilled in the art can implement the technical constructions of the present invention in various forms without departing from the technical spirit or indispensable characteristics of the present invention. Therefore, the above-described embodiments should be construed to be illustrative and limitative from all aspects. Further, the scope of the present invention is defined by the appended claims rather than the above detailed description. Thus, the present invention should be construed to cover all modifications or variations induced from the meaning and range of the appended claims and their equivalents.

[85]

[86]