JP2006129900A - Method and device for detoxification treatment of pcb-containing oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detoxify PCB-containing oil safely and effectively under the condition of normal temperature and normal pressure with a small environmental load for facilitating the detoxification treatment of the PCB-containing oil with a simple process and a simple device for the detoxification treatment, without much cost for construction or operation of treatment equipment, without using a catalyst or a chemical whose handling is difficult, and without requiring high-temperature treatment. <P>SOLUTION: In the detoxification treatment method, PCB contained in the PCB (perchlorobiphenyls)-containing oil is converted to a harmless substance by atomizing, liquidizing or vaporizing the PCB-containing oil in a detoxification treatment reaction part A1, and letting the atomized, liquidized or vaporized PCB-containing oil flow into a silent discharge space in which a silent discharge system 3 is operated. In other words, PCB is converted to the harmless substance utilizing the oxidation/reduction power generated by the application and desorption of electrons in the silent discharge space. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a detoxification treatment method for oil containing the well-known chemical substance PCB (polychlorinated biphenyls = polychlorinated biphenyls), and a PCB-containing oil detoxification treatment device for carrying out the detoxification treatment method. The present invention relates to a method for detoxifying oil containing PCB by superimposing oil spraying technology and silent discharge (dielectric barrier discharge) technology, and an apparatus for detoxifying PCB-containing oil by the method.

PCB is a generic name for isomeric substances having a biphenyl skeleton structure in which two benzene rings are connected, and any one of ten hydrogen atoms arranged around the skeleton is substituted with chlorine (Cl). Because of its high boiling point, it is difficult to thermally decompose, is chemically stable, and has high insulation and high lipophilicity, it has been used as an electrical insulation oil for electrical equipment such as transformers and capacitors in Japan. There were times when it was used in a wide range of applications, as an additive for copying paper, or as a heat medium or lubricating oil. However, because the harmful effects of PCBs on the human body became clear, the production of PCBs was completely discontinued in 1972, and there was a history of high-temperature incineration of the remaining PCB-containing oil. The remaining PCB-containing oil has been continuously stored in a sealed state. However, due to concerns over the leakage of PCB-containing oil that has been continuously stored due to aging of storage facilities over time, the “Special Measures Law on Promotion of Proper Treatment of Polychlorinated Biphenyl Waste” was enforced in 2001. Since then, the PCB detoxification process has become obligatory within 15 years, and it has become an urgent need to deal with the detoxification process for PCB-containing oil currently stored.

Various PCB detoxification methods have been proposed in the past, and these methods can be broadly classified into the following five types.
That is,
[A] Thermal decomposition method by high-temperature incineration The PCB is decomposed into carbon dioxide, water, inorganic salts and incineration ash by spraying PCB in a high-temperature furnace at 1200 to 1400 ° C. As shown in Japanese Patent Application Publication No. 2004-132558 (Patent Document 1), a PCB solution in which PCB is dissolved in a solvent and water are mixed to produce an emulsion, which is electrolyzed with water using a hydrogen / oxygen gas generating means. A type in which PCB is burned at 1400 ° C. or higher by a hydrogen gas burner by supplying the generated hydrogen gas and oxygen gas in a separated state and spraying the emulsion into a combustion chamber in which the hydrogen gas is burned with oxygen gas. Proposed.
[B] Chemical dechlorination and decomposition method Alkaline agents and carbon-based catalysts are mixed with PCB and heated to 300 to 350 ° C in a nitrogen atmosphere under normal pressure to cause chemical reaction, thereby replacing chlorine in PCB with hydrogen. Thus, a substance other than PCB is converted into a harmless biphenyl compound, inorganic salt and water after the treatment. For example, as disclosed in Japanese Patent Application Laid-Open No. 2003-135621 (Patent Document 2), gelation is achieved by mixing and stirring PCB and chlorine compound with silicone and toluene, and mixing and stirring an alkali agent catalyst. It has been proposed to initiate an exothermic reaction at 40 to 120 ° C. to dechlorinate PCB.
[C] Hydrothermal oxidative decomposition method In the hydrothermal oxidative decomposition method, so-called supercritical water (usually supercritical water at 650 ° C. or higher and 250 atmospheric pressure or higher) in a state exceeding 374 ° C. and 218 atm. 380 ° C using supercritical water oxidation method that decomposes PCB into carbon dioxide gas, water and hydrochloric acid by using strong oxidizing power, and hot water in which oxygen and sodium carbonate are added to water just before supercritical There is a hydrothermal decomposition method in which PCB is oxidized and decomposed at 270 atm. For example, as disclosed in Japanese Patent Application Laid-Open No. 2003-175327 (Patent Document 3), a pre-reactor and a post-reactor for decomposing a halogenated organic compound in a supplied processing solution under a high temperature and high pressure environment are provided. A hydrothermal oxidative decomposition apparatus is also proposed which supplies the processing liquid in the former stage reactor to the inside of the latter stage reactor.
[D] Photolysis method A PCB is dechlorinated by irradiating the PCB with ultraviolet rays having a wavelength of 250 to 300 nm, and a trace amount of residual PCB is decomposed by a noble metal catalyst or a microorganism. As shown in the publication (Patent Document 4), an excimer light emitting part having an internal electrode, a metal container that is disposed outside the excimer light emitting part and fills a liquid containing an organic compound, and between the internal electrode and the metal container Excimer light that generates an organic compound-containing liquid filled between the excimer light emitting part and the metal container from the excimer light emitting part using an organic substance decomposing apparatus equipped with a power source that generates a dielectric barrier discharge by applying a voltage to Have been proposed to decompose into carbon dioxide or water.
[E] Reductive thermochemical decomposition method As a reductive thermochemical decomposition method, PCB is finally converted into hydrochloric acid and methane by a reduction reaction in which PCB is heated under normal pressure in a pure hydrogen atmosphere and dechlorinated and decomposed without using a catalyst. Gas phase hydrogen reduction method that decomposes into carbon monoxide, carbon dioxide, hydrogen and a few lower hydrocarbons, neutralizes hydrochloric acid and discharges it outside the system to make it harmless, or blowing PCB waste into an iron melting bath The PCB is decomposed once to the atomic level, and then the pressure, temperature, and oxygen supply rate are adjusted to control the chemical composition of the product. PCB is decomposed and rendered harmless in the plasma (decomposed and detoxified by reacting PCB containing oil and oxygen using a direct current plasma jet) A plasma melting method or the like is known in which incineration ash or incineration fly ash left by thermal incineration is melted and solidified using thermal energy of plasma to make it slag and detoxify. For example, as disclosed in Japanese Patent Application Laid-Open No. 2003-19434 (Patent Document 5), soil contaminated with PCB is spirally moved by a cyclone and supplied to the plasma processing vessel, and the cyclone or the plasma processing vessel is supplied. There has been proposed a method for detoxifying a PCB by chemically reacting with an activated plasma of a processing gas introduced from the gas inlet.
Japanese Patent Laid-Open No. 2004-132558 Japanese Patent Laid-Open No. 2003-135621 Japanese Patent Laid-Open No. 2003-175327 Japanese Patent Laid-Open No. 11-319816 Japanese Patent Laid-Open No. 2003-19434

However, any of the conventional PCB detoxification processing methods as described above has a great difficulty in practical use. That is, in the pyrolysis method by high temperature incineration, it is difficult to manage the processing furnace for incineration at high temperature, and there are problems that undecomposed PCB remains in the incineration ash, and dioxins that are more toxic than PCB at low processing temperature. The chemical dechlorination and decomposition method requires a strong alkali agent for effective dechlorination, and the strong alkali agent is generally difficult to handle. NaOH, KOH, Na , K is difficult to handle in order. In addition, chemical dechlorination decomposition method, hydrothermal oxidative decomposition method, photodecomposition method and reductive thermal chemical decomposition method all require large-scale equipment, which may increase plant construction costs and equipment operation costs. This is a major difficulty in practical use, and is also regarded as a problem in terms of processing costs when a large amount of oil containing PCB is harmlessly processed.

  In view of the above-described practical difficulties of various conventional PCB detoxification treatment techniques, the present invention provides a simple detoxification treatment process and treatment apparatus for promoting detoxification treatment of PCB-containing oil. Therefore, the construction cost and the operation cost of the processing equipment are not bulky, and it does not require a high temperature treatment such as the plasma melting method described above without using a strong alkali agent or a special catalyst / chemical that is difficult to handle. A highly practical PCB-containing oil detoxification method that can safely and effectively detoxify PCB-containing oil under normal pressure, and a practicality for implementing the detoxification treatment method. An object of the present invention is to realize a detoxifying device for high PCB-containing oil.

  In order to achieve the above-mentioned problems / objects, the present invention is to atomize, drop, or vaporize a PCB-containing oil, and perform the silent discharge operation on the atomized, drop-formed, or vaporized PCB-containing oil. In the silent discharge space, the PCB in the PCB-containing oil is converted into a harmless substance. That is, the present invention is based on the principle of converting PCB into a harmless substance by utilizing the redox power generated by the electron donation and desorption in the silent discharge space.

  In addition, by supplying PCB-containing oil with an inert gas to the spray nozzle and supplying the inert gas separately to the spray nozzle, the PCB-containing oil is atomized, dropletized or vaporized and ejected from the spray nozzle. The PCB-containing oil that has been ejected is circulated through the silent discharge space formed between the silent discharge barriers of a plurality of dielectrics each having a discharge electrode plate mounted on one side, thereby detoxifying first. PCBs still remaining in the finished oil are converted into harmless substances.

  In addition, the PCB-containing oil in which the PCB remains even after being detoxified through circulation in the silent discharge space is recovered, and the recovered PCB-containing oil is atomized, dropletized, or vaporized again. The PCB-containing oil converted into droplets or vaporized is circulated in the silent discharge space during the silent discharge operation, thereby converting the PCB remaining in the PCB-containing oil into a harmless substance.

  On the other hand, as a detoxification treatment device for PCB-containing oil, a means for atomizing, dropletizing or evaporating PCB-containing oil and a silent discharge system through which the atomized, dropletized or vaporized PCB-containing oil circulates And a detoxification processing apparatus having a power supply for supplying silent discharge energy to the silent discharge system as a main part.

  Also, a spray nozzle that atomizes, drops or vaporizes PCB-containing oil by supplying PCB-containing oil and inert gas, and silent discharge of a plurality of dielectrics each having a discharge electrode plate mounted on one side Silent discharge where PCBs containing oil that is atomized, dropletized, or vaporized circulates in the silent discharge space formed between the silent discharge barriers facing each other by arranging the barriers in parallel with each other A PCB-containing oil detoxification treatment apparatus comprising a reactor having a system and a power supply for supplying silent discharge energy to the silent discharge system is constituted.

  Furthermore, as a silent discharge system that can be accommodated in the reactor, a plurality of dielectric silent discharge barriers each having a discharge electrode plate mounted on one side thereof are arranged in parallel with a space therebetween, and the silent discharge barriers facing each other are arranged. A silent discharge space is formed between them, and two electrode groups are formed by alternately selecting discharge electrode plates in parallel with the silent discharge barrier, one of which is the ground electrode, and the other electrode The group shall be connected to the power output terminal.

  According to the PCB-containing oil detoxification treatment method and the detoxification treatment apparatus according to the present invention, a silent discharge comprising a spray nozzle for atomizing, dropletizing, or vaporizing PCB-containing oil, and a dielectric barrier is provided. The detoxification process is performed by combining the systems, the process of the detoxification process is very simple, the construction cost and the use cost of the detoxification treatment apparatus can be kept low, the environmental cost is small, safe and It is a detoxification treatment technology that can be implemented effectively. Further, the reaction in the detoxification treatment according to the present invention does not require a high-temperature treatment as seen in the plasma melting method described above, and is extremely easy to handle at room temperature and normal pressure, and does not require a special catalyst or chemical. There is no generation of residue. Further, the treated oil can be used as a fuel. Further, since the detoxification process according to the present invention is a gas-liquid mixing process, there is an effect that the fly ash generated during high-temperature incineration as in the prior art and the landfill problem of solidified incineration ash do not occur. Therefore, it is a practical effect as a method for quickly discarding the remaining PCB within a limited time while considering the environment.

An extremely excellent embodiment of the PCB-containing oil detoxification method according to the present invention is the above-described method, wherein the PCB-containing oil is supplied to the spray nozzle with nitrogen gas and simultaneously the nitrogen gas is supplied to the spray nozzle separately. The PCB-containing oil is atomized, dropletized or vaporized and ejected from the spray nozzle, and the ejected PCB-containing oil is spaced by a plurality of dielectric silent discharge barriers each having a discharge electrode plate mounted thereon. A high voltage is applied between two electrode groups in which a silent discharge space is formed between the silent discharge barriers facing each other and the discharge electrode plates of the silent discharge barriers are alternately selected. The PCB in the PCB-containing oil is converted into a harmless substance by circulating in the silent discharge space of the silent discharge system where the silent discharge is generated, and further, the silent The treated oil that has been detoxified through circulation in the electric space is recovered and atomized, dropletized, or vaporized again, and the atomized, dropletized, or vaporized PCB-containing oil is again silenced. It is a detoxification treatment method for PCB-containing oil, which circulates in a silent discharge space during discharge operation and converts PCB still remaining in the treated oil into harmless substances.

  An extremely excellent embodiment of the PCB-containing oil detoxification processing apparatus according to the present invention includes a pressure vessel that stores a PCB-containing oil that requires detoxification processing, and supplies the PCB-containing oil to atomize, dropletize, or steam. A nitrogen gas cylinder filled with nitrogen gas for atomization, a spray nozzle for atomizing, dropletizing, or vaporizing the PCB-containing oil, and an atomized, dropletized, or vaporized PCB-containing oil Reactor incorporating a silent discharge system that circulates, a power source that supplies silent discharge energy to the silent discharge system, a recovery container that recovers treated oil detoxified in the reactor, and a process recovered in the recovery container Means for returning the finished oil to a pressure vessel for storing the PCB-containing oil, and the silent discharge system includes a plurality of dielectric silent discharge barriers each having a discharge electrode plate mounted on one side as spacers. A silent discharge space is formed in which the atomized, dropletized, or vaporized PCB-containing oil flows between the silent discharge barriers that are arranged side by side with a space therebetween and discharge of each silent discharge barrier. The electrode plates are alternately selected and formed into two electrode groups, one electrode group of which is a ground electrode and the other electrode group is an electrode connected to the output terminal of the power source, the pressure vessel and the The nitrogen gas cylinder is communicated with a pipe via a liquid-side pressure reducing valve, the PCB-containing oil in the pressure vessel and the spray nozzle of the reactor are communicated with a pipe via a liquid flow rate adjustment valve, and This is a PCB-containing oil detoxifying device in which a nitrogen gas cylinder and the spray nozzle are communicated with each other via a gas side pressure reducing valve.

  Embodiments of a PCB-containing oil detoxification treatment method and a PCB-containing oil detoxification treatment apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a PCB-containing oil detoxification treatment apparatus according to the present invention, FIG. 2 is a perspective view of a silent discharge system of the detoxification treatment apparatus, and FIG. 3 is a cross-sectional view taken along line SS ′ in FIG. It is sectional drawing of a silent discharge system. FIG. 4 is a graph showing a change in the residual concentration of PCB with respect to the number of discharge treatments, which is the result of the detoxification treatment method for PCB-containing oil according to the present invention.

  As shown in FIG. 1, a PCB-containing oil detoxification treatment apparatus shown as an embodiment of the present invention includes a detoxification treatment reaction part A1 which is the heart of the apparatus, and a PCB-containing oil in the detoxification treatment reaction part A1. PCB-containing oil supply unit A2 for supplying detoxification, high-voltage power supply unit A3 for supplying silent discharge energy to the detoxification treatment reaction unit A1, and treated oil for recovering the detoxified oil in the detoxification treatment reaction unit A1 It consists of a collection unit A4.

The detoxification treatment reaction part A1 comprises a container-like reactor 1, and in the reactor 1, a spray nozzle 2 for atomizing, dropping or vaporizing the supplied PCB-containing oil into the reactor 1 and silent. A silent discharge system 3 for generating a discharge (dielectric barrier discharge) is provided. Reference numeral 4 denotes a lower funnel that receives the treated oil detoxified in the reactor 1, and 5 denotes a lead-out pipe that guides the treated oil received by the lower funnel 4 to the treated oil recovery section A4. The structure of the silent discharge system 3, as shown in FIGS. 2 and 3, is 8 sheets of length 200 mm × width 100 mm × thickness 3 mm in which a discharge electrode plate 31 of a stainless steel plate having a thickness of 0.1 mm is attached on one side. Glass plates (for example, trade name: TEMPAX) 32 are integrated in a parallel state while maintaining a silent discharge space 33 with a gap length of 2 mm. The glass plate 32 serves as a silent discharge barrier of the silent discharge system 3, and in order to form a silent discharge space 33 with a gap length of 2 mm between the glass plates 32 facing each other, the glass plate 32 extends along the long sides facing each other. Seven chamber silent discharge spaces 33 are formed by interposing glass epoxy spacers 2 having a thickness of 2 mm between glass plates 32 facing each other. Further, the discharge electrode plates 31 arranged in parallel with the glass plate (silent discharge barrier) 32 are alternately and sequentially selected to form two electrode groups 31a and 31b, which belong to one of the electrode groups 31a. The discharge electrode plate 31 is a ground electrode, and the discharge electrode plate 31 belonging to the other electrode group 31 b is connected to the high voltage output terminal 16 a of the high voltage power transformer 16. A high voltage of commercial frequency AC 10 kV is applied between the discharge electrode plate 31 belonging to the electrode group 31a and the discharge electrode plate 31 belonging to the other electrode group 31b from the high voltage power transformer of the high voltage power supply unit A3. As a result, silent discharge (dielectric barrier discharge) is generated and maintained in the silent discharge space 33 of the silent discharge system 3 at room temperature and normal pressure.

The PCB-containing oil supply unit A2 includes a stainless steel pressure vessel 7 that stores PCB-containing oil 6 that requires detoxification, and a nitrogen gas cylinder 8 that contains nitrogen gas that is an inexpensive inert gas. The nitrogen gas cylinder 8 and the spray nozzle 2 of the reactor 1 communicate with each other through a pipe 10 via a gas side pressure reducing valve 9, and the nitrogen gas cylinder 8 and the pressure vessel 7 are connected via a liquid side pressure reducing valve 11. The pipe 12 communicates with the PCB-containing oil 6 in the pressure vessel 7 and the spray nozzle 2 of the reactor 1 through the pressure regulation valve 13 and the liquid flow rate regulation valve 14 through the pipe 15. is there. The pipes 10, 12, and 15 are chemically stable Teflon (registered trademark) pipes. The high-pressure nitrogen gas stored in the nitrogen gas cylinder 8 is supplied by pumping the PCB-containing oil 6 in the pressure vessel 7 to the spray nozzle 2 of the reactor 1 and atomizing, dropletizing, or vaporizing with the spray nozzle 2. It functions to spray toward the silent discharge system 3 inside. That is, the nitrogen gas supplied from the nitrogen gas cylinder 8 is sent to the spray nozzle 2 attached to the upper part of the reactor 1 through the gas side pressure reducing valve 9 and the pipe 10 and simultaneously through the liquid side pressure reducing valve 11 to the PCB. It is also sent to the pressure vessel 7 filled with the containing oil 6. Then, the PCB-containing oil 6 pressurized with nitrogen gas in the pressure vessel 7 is sent to the spray nozzle 2 through the liquid flow rate adjusting valve 14 and the pipe 15. The pressure and flow ratio of the gas (nitrogen gas) flowing through the pipe 10 and the liquid (PCB-containing oil 6) flowing through the pipe 15 are the gas side pressure reducing valve 9, the liquid side pressure reducing valve 11, the pressure adjusting valve 13, and the liquid flow rate adjusting valve. The PCB-containing oil 6 is sprayed toward the silent discharge space 33 of the silent discharge system 3 installed in the reactor 1 after being mixed with nitrogen gas by the spray nozzle 2. . Then, the PCB-containing oil 6 sprayed from the spray nozzle 2 flows into the silent discharge space 33 of the silent discharge system 3 where the silent discharge continues as shown by the arrow M in FIG. In the process of passing through the space 33, chlorine of the PCB component in the oil is removed and detoxified.

  The high-voltage power supply unit A3 includes a high-voltage power supply transformer 16, and a high-voltage side output terminal 16a of the high-voltage power supply transformer 16 has an electrode group 31b disposed on the glass plate (silent discharge barrier) 32 of the silent discharge system 3. Is connected to the discharge electrode 31 belonging to. A high voltage of commercial frequency AC of 10 kV is applied between the discharge electrode plate 31 belonging to the electrode group 31a and the discharge electrode plate 31 belonging to the other electrode group 31b. Reference numeral 17 denotes a voltmeter attached to the high voltage power transformer 16, and 18 denotes an ammeter attached to the high voltage power transformer 16.

The treated oil recovery section A4 is composed of a collection container 20, a mist trap 21, a hexane trap 22, and an activated carbon trap 23 connected in series, and the treated oil detoxified in the reactor 1 is in the lower funnel 4. It is received, condensed and liquefied, guided to the collection container 20 and accumulated. Further, the nitrogen gas containing the oil mist discharged from the collection container 20 is released into the atmosphere after the oil mist is removed and purified through the mist trap 21, the hexane trap 22, and the activated carbon trap 23. Further, the treated oil recovered in the recovery container 20 is returned to the pressure container 7 of the PCB-containing oil supply unit A2, and the detoxification process cycle described above is repeatedly executed, whereby the detoxification process of the PCB-containing oil is effectively performed. Can be increased.

  In addition to the above examples, the PCB-containing oil could be rendered harmless without any problems even if various conditions such as the size of the glass and electrodes constituting the reactor and the silent discharge system, the supply gas flow rate, and the gas pressure were changed. . Further, in the above embodiment, nitrogen gas is used to supply the PCB-containing oil 6 to the reactor 1 and spray it into the reactor 1, but argon gas or argon / nitrogen mixed gas may be used instead of nitrogen gas. Similar results were obtained. Moreover, in the said Example, although the glass plate was employ | adopted as a dielectric barrier which forms the silent discharge space 33, even if it replaced the glass plate with the insulating ceramic plate, the substantially same result was obtained. Therefore, it is considered that the silent silent discharge barrier may be a dense material having high electrical insulation. Moreover, even if the high voltage applied to the silent discharge space 33 is a pulse wave voltage, the PCB-containing oil can be rendered harmless without any problem.

  Further, using the PCB-containing oil detoxifying apparatus according to the present invention shown in FIG. 1, the flow rate ratio between the PCB-containing oil supplied to the reactor 1 and the nitrogen gas is adjusted under the processing conditions shown in Table 1 below. Adjust the spray nozzle pattern to match the inlet shape of the silent discharge space, and perform silent discharge processing as fine oil mist or droplets so that the PCB-containing oil cannot be visually recognized. The treated oil recovered in the treated oil recovery unit A4 is returned to the pressure vessel 7 and reprocessed, and the reprocessing procedure is repeated 6 times to discharge the initial PCB-containing oil state before detoxification. When the number of times of discharge processing was set to 0, and the discharge processing times of the first time, the third time, and the sixth time were completed, the residual PCB concentration in the processed oil recovered by the processed oil recovery unit A4 was measured. Remaining PC The change in B concentration was as shown in FIG. That is, FIG. 4 shows the change in the PCB residual concentration with respect to the number of discharge treatments, and shows the effect that the PCB residual concentration after the sixth discharge treatment is substantially halved with respect to the initial PCB residual concentration of 26 ppm. In the above embodiment, the discharge treatment process is performed in one step and the repetition treatment is performed six times. However, it is more effective to further increase the number of repetition treatments by making the discharge treatment step a multi-stage treatment.

Table 1

PCBs have many isomers depending on the number and position of chlorine substitution, and their toxicity varies greatly. Therefore, it is important to efficiently dechlorinate and detoxify. In this invention, oil containing PCB is atomized, dropletized or vaporized and sprayed, and the chlorine-containing oil is released from the sprayed PCB-containing oil by silent discharge energy, thereby detoxifying the PCB-containing oil. However, since the current during silent discharge is very small due to the presence of a dielectric barrier such as a glass plate, the operating cost of the apparatus is low and the reliability of long-time operation is high. In addition, since the voltage applied to the silent discharge system may be about 10 kV, it can be used even with a normal neon transformer, so that it is extremely economical in terms of the device price. Furthermore, the detoxification reaction can be performed at normal temperature and pressure, and no special catalyst or chemical is required. Therefore, the detoxification method and equipment are extremely easy to handle, and no residue is generated by the detoxification process. . Therefore, the practical effect of the present invention is extremely great.

  The detoxification treatment of PCB-containing oil that is currently stored continuously is a major and urgent issue in the industry. The detoxification treatment method for PCB-containing oil and the detoxification treatment apparatus according to the present invention are It is thought that it can be used greatly to remove negative heritage.

The block diagram of the detoxification processing apparatus of PCB containing oil which concerns on this invention. The perspective view of the silent discharge system of the same detoxification processing apparatus. Sectional drawing of the silent discharge system cut | disconnected by the S-S 'line | wire of FIG. The PCB residual density change figure with respect to the frequency | count of the discharge process in the detoxification processing method of the PCB containing oil which concerns on this invention.

Explanation of symbols

A1: Detoxification treatment reaction part
A2: PCB-containing oil supply section
A3: High voltage power supply (power supply)
A4: Treated oil recovery part 1: Reactor 2: Spray nozzle 3: Silent discharge system 4: Lower load 5: Outlet pipe 6: PCB containing oil 7: Pressure vessel 8: Nitrogen gas cylinder 9: Gas side pressure reducing valves 10, 12, 15: Pipe 11: Liquid side pressure reducing valve 13: Pressure adjusting valve 14: Liquid flow rate adjusting valve 16: High voltage power transformer (power source)
16a: High voltage output terminal (power output terminal)
17: Voltmeter 18: Ammeter 20: Collection vessel 21: Mist trap 22: Hexane trap 23: Activated carbon trap 31: Electrode plate 31a, 31b for discharge: Electrode group 32: Glass plate (dielectric silent discharge barrier)
33: Silent discharge space 34: Spacer

Claims (6)

  The PCB-containing oil is atomized, dropletized, or vaporized, and the atomized, dropletized, or vaporized PCB-containing oil is circulated in the silent discharge space during the silent discharge operation. A method for detoxifying PCB-containing oil, characterized in that the PCB contained therein is converted into a harmless substance.   By supplying the PCB-containing oil with the inert gas to the spray nozzle and supplying the inert gas to the spray nozzle separately, the PCB-containing oil is atomized, dropletized or vaporized and ejected from the spray nozzle. The squirted PCB-containing oil is circulated in the silent discharge space formed between the dielectric silent discharge barriers that are mounted on one side and the discharge electrode plates are arranged opposite to each other. A method for detoxifying a PCB-containing oil, which comprises converting PCB in the PCB-containing oil into a harmless substance.   After circulating through the silent discharge space and detoxified, the PCB-containing oil in which the PCB still remains is recovered, and the recovered PCB-containing oil is atomized or dropletized or vaporized again. 2. The PCB-containing oil is converted into a harmless substance by flowing the droplet- or vaporized PCB-containing oil in a silent discharge space during silent discharge operation. The method for detoxifying PCB-containing oil according to claim 2.   Means for atomizing, dropletizing, or vaporizing PCB-containing oil, silent discharge system through which the atomized, dropletized, or vaporized PCB-containing oil flows, and supplying silent discharge energy to the silent discharge system A PCB-containing oil detoxification processing apparatus comprising a power supply unit that performs the above-described operation.   A spray nozzle for atomizing, dropletizing, or vaporizing the PCB-containing oil by supplying PCB-containing oil and an inert gas, and a plurality of dielectric silent discharge barriers each having a discharge electrode plate mounted on one side A silent discharge system in which a silent discharge space is formed between the silent discharge barriers arranged side by side with a space therebetween, and the atomized, dropletized, or vaporized PCB-containing oil circulates in the silent discharge space A PCB-containing oil detoxification treatment apparatus comprising: a reactor having a power source for supplying silent discharge energy to the silent discharge system. The silent discharge system that fits in the reactor is composed of a plurality of dielectric silent discharge barriers, each having a discharge electrode plate mounted on one side, spaced in parallel via a spacer, and between the silent discharge barriers facing each other. A silent discharge space is formed, and the discharge electrode plates in parallel with the silent discharge barrier are alternately selected and formed into two electrode groups, with one electrode group serving as a ground electrode, 6. The PCB-containing oil detoxifying device according to claim 4 or 5, wherein the electrode group is an electrode connected to a power output terminal.

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