JP2009183838A - Detoxification treatment method for member in transformer containing organic halogen compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method with which, from a transformer of a volume of ≥100 L (other than a pole transformer) charged with insulating oil comprising a trace amount of organic halogen compound, the insulating oil is extracted, thereafter, the organic halogen compound remaining in a member at the inside of the transformer can be easily and economically subjected to detoxification treatment in a short period of time before disassembling the transformer without by-producing harmful dioxins. <P>SOLUTION: From the transformer (other than a pole transformer) of a volume A of ≥100 L charged with insulating oil comprising the trace amount of organic halogen compound, the insulating oil is extracted, and, in the case, the volume B of the insulating oil remaining in the transformer satisfies 0.01<B/A≤0.2, a cleaning liquid composed of an isopropyl alcohol solution comprising alkali of 0.01 to 2.0 wt.% is filled into the transformer after the oil extraction in such a manner that 4≤C/B≤60 is satisfied, subsequently, and while circulating the cleaning liquid in a catalyst filling device, the liquid is circulated so as to perform cleaning, and further, while holding an alkali concentration, the organic halogen compound is decomposed so as to detoxify the internal member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transformer (excluding a pole transformer) having a capacity of 100 L or more in which an insulating oil containing a trace amount of an organic halogen compound is contained, and the transformer after removing the insulating oil is used as a transformer container. It is related with the method of detoxifying the internal member of a transformer, circulatingly cleaning with a washing | cleaning liquid before disassembling into an internal member.

  Among various organic halogen compounds, polychlorinated biphenyl (hereinafter abbreviated as PCB) is extremely harmful to living organisms including the human body. Therefore, it was designated as a specified chemical substance in 1973 and its manufacture, import, and use were prohibited. ing. However, after that, tens of thousands of tons of PCBs are left untreated without determining an appropriate disposal method.

In order to detoxify the transformer container and the internal member containing the insulating oil containing the organic halogen compound, the following methods are generally considered.
(1) Drain the contaminated insulating oil from the transformer, clean the transformer after it has been drained, disassemble it, separate it into a container (case) and internal members, and individually separate the residual PCB from the prescribed graduation standard value A method of cleaning until the condition is satisfied (conventional method, see flowchart of FIG. 6).
(2) A method of removing the contaminated insulating oil from the transformer, heating the whole of the transformer after the oil removal or vacuum heating, and evaporating and removing the PCB.
(3) A method of removing the contaminated insulating oil from the transformer, immersing the entire transformer in a washing tank without disassembling the drained transformer, and simultaneously washing the container (case) and the internal member.
(4) Drain the contaminated insulating oil from the transformer, do not disassemble the transformer after draining, put the cleaning solution into the transformer to exude the organic halogen compound, and simultaneously put the container (case) and the internal members together Method of cleaning (see flowchart in FIG. 7).

  However, since the transformer has a complicated internal structure, it is virtually impossible to extract all the insulating oil. Therefore, in the above method (1), after the transformer is first cleaned, the internal member must be taken out from the container while containing the PCB and disassembled, and careful work in a sealed space is required. Therefore, there is a problem that it takes work time and the burden on the worker is large.

  The method (2) has no problem as in the method (1) and has the advantage that the transformer can be disassembled. However, the method requires a large furnace such as a heating furnace or a vacuum heating chamber in which the entire container can be stored. In addition, the reaction requires heating at 260 to 600 ° C. by vacuum heating, and heating at 850 ° C. or more in the case of a heating furnace.

  The methods (3) and (4) have the advantage that the container (case) and the internal member are cleaned at the same time, so that there is no need for treatment of newly generated cleaning waste liquid, and the internal member is rendered harmless during dismantling. Therefore, there are few restrictions on work. However, the method (3) requires a washing tank that can immerse the entire transformer, and large-scale transformers with a capacity of 1000L or 10,000L (excluding pole transformers) require large washing equipment. I have to be. In the case of such a large transformer, moving to the washing tank itself requires a great amount of labor and requires careful work, so that the burden on the worker is large. For this reason, it is desirable that the transformer can be detoxified at the transformer store without moving the transformer as much as possible and without installing special equipment.

  For the above reasons, after extracting the insulating oil containing PCB, the internal parts of large transformers with a small amount of organic oil containing organic halogen compounds remain harmless at low cost and without using large-scale equipment. To achieve this, the method (4) is considered appropriate.

  By the way, the following various methods have been proposed for cleaning the transformer container after draining the insulating oil. However, a method for cleaning and detoxifying internal members of large transformers (excluding pole transformers) before disassembly has not been reported yet.

  For example, in Patent Document 1, a column transformer after draining insulating oil containing PCB is first washed with water by a water jet, and then disassembled and separated into a case and an internal member. Although the method of detoxifying the pole transformer case by washing with is disclosed, the internal member cannot be detoxified before disassembly by this method. Patent Document 2 discloses a method in which an internal member of a transformer is immersed in a cleaning liquid such as propanol so that the cleaning liquid enters the gap between the members, and the PCB attached to the gap is cleaned and removed. Even in this method, it is necessary to clean the member after disassembly.

  Patent Document 3 discloses a method in which contents are extracted from a transformer containing an organic chlorine compound, and then the inside of the transformer is circulated and cleaned using isopropyl alcohol. Basically, it is a method that requires cleaning of members exceeding a predetermined graduation standard value. Patent Document 4 discloses a method of circulating and cleaning the inside of the transformer after removing the PCB from the transformer. In this method, after circulating and cleaning, the internal member is disassembled and separated, and the internal member is vacuum heated. This is a method of performing separation treatment or solvent washing treatment.

  On the other hand, as a method of detoxifying the insulating oil containing a small amount of PCB that has entered the pole transformer, alkali and isopropyl alcohol are added to the pole transformer, and the mixture of insulating oil and isopropyl alcohol is filled with the catalyst. A method of decomposing PCB in oil by circulating it in a transformer while circulating it in a device has been disclosed (see Patent Document 5). In this method, PCB remaining in the internal member is leached and decomposed simultaneously with the oil decomposition treatment, but the leaching is very slow and is also affected by the PCB concentration in the circulating liquid. It is substantially difficult to judge that the internal member can also be rendered harmless simply because the PCB concentration in the liquid has become 0.5 ppm or less during the decomposition treatment.

Further disclosed is a method of detoxifying PCB in insulating paper by adding alkali and isopropyl alcohol to a transformer container and circulating the isopropyl alcohol solution in the transformer while circulating the catalyst filling device. (See Patent Document 6). It is disclosed that PCB contained in insulating paper and wood pieces diffuses and elutes into isopropyl alcohol with time, so that if it is decomposed, the PCB concentration can be reduced with time. No specific detoxification process conditions are disclosed.
Japanese Patent No. 377941 (Claim 1 etc.) JP 2003-24885 A (Claim 1, Claim 10, etc.) JP 2003-145122 A (Claim 1 etc.) JP2003-117517A (Claim 1 etc.) Japanese Patent No. 3626960 (Claim 1 etc.) Japanese Patent Laying-Open No. 2006-142278 (Claim 1, Claim 3, FIG. 1, etc.)

  The present invention has been made in view of the above problems, and after extracting the insulating oil from a transformer (excluding a pole transformer) having a capacity of 100 L or more containing an insulating oil containing a trace amount of an organic halogen compound. The organic halogen compounds remaining on the internal parts of the transformer are detoxified before disassembling the transformer into the container and the internal parts, easily and economically, and without producing harmful dioxins as a by-product. It is an object of the present invention to provide a detoxifying treatment method for an organic halogen compound-containing transformer internal member.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies on 100 L class, 1000 L class, and 10,000 L class transformers (excluding pole transformers). As a result, the shapes of these large transformers are almost similar regardless of capacity, so the amount of residual oil after extracting the insulating oil from the drain valve from the transformer containing contaminated insulating oil is The knowledge that it becomes 1 to 20% of the capacity of the original transformer regardless of the usage and capacity of the transformer. Then, a cleaning liquid composed of an alkali-containing isopropyl alcohol solution is put into the transformer, and then the inside of the transformer is circulated and cleaned without changing or adding the cleaning liquid while circulating this solution to the catalyst filling device. An attempt was made to clean the inner member until it was satisfied.

As a result, unexpectedly, if the transformer container is regarded as a reaction container and the amount of the cleaning liquid with respect to the residual oil is set to 4 to 60 times, it is only necessary to add the alkali timely without adding the cleaning liquid. It is possible to detoxify organohalogen compounds remaining in transformer internal members (iron cores, coils, insulating paper, wood chips, etc.) until the graduation standard is met. Even when a transformer is attached with a radiator, It was found that even if the radiator was removed, as long as the capacity of the radiator could be grasped, it was only necessary to fill the washing liquid accordingly.
In addition, by clarifying the amount of residual oil, it has been found that the time required for detoxification treatment can be accurately predicted and the amount of catalyst can be optimized, eliminating the need to use an expensive catalyst. The present invention has been completed.

That is, the present invention is as follows.
(1) Insulating oil remaining in a transformer after extracting the insulating oil from a transformer (excluding a pole transformer) containing an insulating oil containing a trace amount of an organic halogen compound and having a capacity A of 100 L or more In the case where the capacity B satisfies 0.01 <B / A ≦ 0.2,
The transformer after draining the insulating oil was filled with a cleaning liquid composed of an isopropyl alcohol solution containing 0.01 to 2.0% by weight of alkali so that the capacity C satisfies 4 ≦ C / B ≦ 60. rear,
While circulating the washing liquid in the transformer through the catalyst filling device and circulatingly washing in the transformer, while adding alkali so that the alkali concentration is kept in the range of 0.01 to 2.0% by weight, Decomposes organic halogen compounds remaining on internal members
A detoxifying treatment method for an organic halogen compound-containing transformer internal member.
(2) The harmless organic halogen compound-containing transformer internal member according to (1) above, wherein the transformer after draining the insulating oil has no radiator and 4 ≦ C / B ≦ 50 Processing method.
(3) The harmless organic halogen compound-containing transformer internal member according to (1) above, wherein the transformer after draining the insulating oil is provided with a radiator and 5 ≦ C / B ≦ 60. Processing method.
(4) The organic halogen according to (1) or (2) above, wherein the cleaning liquid in the transformer is discharged from the opening on the bottom side after the radiator is removed from the transformer and led to a catalyst filling device. Detoxification method for compound-containing transformer internal member.
(5) The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of (1) to (4), wherein the cleaning temperature is from room temperature to 60 ° C.
(6) The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of (1) to (5), wherein the alkali is at least one selected from NaOH and KOH.
(7) The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of (1) to (6), wherein the catalyst is a palladium-supported carbon compound.
(8) The organic halogen compound-containing transformer internal member according to any one of (1) to (7), wherein microwaves are irradiated to the cleaning liquid in the catalyst filling device when the organic halogen compound is decomposed. Detoxification treatment method.

According to the present invention, a troublesome pumping operation is unnecessary, and an organic halogen compound adhering or soaking into an internal member such as a coil or paper or a piece of wood is exuded and dissolved in an appropriate amount of a cleaning solution, and then alkalinated in a timely manner. In addition, since the cleaning liquid is circulated in the transformer while flowing through the catalyst filling device, the internal member can be rendered harmless by the simultaneous cleaning and decomposition of the organic halogen compound. Whether the transformer is attached to the radiator or the radiator is removed from the transformer, the amount of cleaning liquid in the transformer does not change substantially, making it easier to work with more options depending on the situation. .
Since the amount of residual oil is clear, the amount of residual organic halogen compound can be determined from the concentration of organic halogen compound in the residual oil and the amount of residual oil. For this reason, the time required for the detoxification treatment can be accurately predicted, and the amount of catalyst used for the decomposition can be optimized, so that the economy is greatly improved.

  It is not necessary to transport the transformer after draining the insulating oil to a detoxification treatment facility, and since large-scale equipment is not required and can be carried out under normal pressure, it can be cleaned at the site such as a factory or transformer storage. It is a detoxification process that is economical and safe.

  If washing is carried out at a temperature between normal temperature and 60 ° C., harmful dioxins are not by-produced during the treatment.

  If KOH or NaOH is used as the alkali and a metal-supported carbon compound is used as the decomposition catalyst, the organic halogen compound can be decomposed with high efficiency, so that the processing cost can be reduced.

  Decomposition can be facilitated by irradiating the cleaning liquid flowing through the catalyst layer with microwaves in the catalyst filling device.

  Hereinafter, the detoxification treatment method for an internal component of an organic halogen compound-containing transformer according to the present invention will be described in detail with reference to the drawings.

In the present invention, transformers having a capacity A of 100 L or more (excluding pole transformers) are targeted. 1 and 2 are diagrams for explaining an embodiment of the detoxification processing method of the present invention. FIG. 1 is a schematic view showing an embodiment in which circulation cleaning is performed with a radiator attached to a transformer. FIG. 2 is a schematic view showing an embodiment in which the circulation cleaning is performed with the radiator removed from the transformer, and the cleaning liquid in the transformer is discharged from the bottom-side hole 2 formed when the radiator is removed, and the catalyst filling device. To introduce.
DESCRIPTION OF SYMBOLS 1 is a transformer, 2 is an opening using the hole formed after removing a radiator, 3 is the member which obstruct | occluded the hole formed after removing a radiator, 4 is a radiator, 6 is a microwave apparatus, 7 is a catalyst filling apparatus , 8 is a return tank. Reference numeral 10 denotes a cleaning liquid storage tank. Alkaline, which is previously dissolved in an appropriate amount of isopropyl alcohol by stirring, is added to the storage tank 10 containing isopropyl alcohol. A cleaning liquid made of isopropyl alcohol to which alkali is added is introduced from the storage tank 10 into the transformer 1 through a pipe.

  Separately from the circulation line for circulating the catalyst filling device, the cleaning liquid in the transformer is circulated through the pump 11. By installing this pump 11, the cleaning liquid can be circulated even in a large transformer having a capacity of 100 L or more, so that the leaching / dissolution of the organic halogen compound from the internal member is promoted and the processing time is shortened. is there.

  The insulating oil contained in the transformer before detoxification treatment is an insulating oil containing a trace amount of an organic halogen compound (content: 1 ppm to 10,000 ppm, preferably 1 ppm to 500 ppm).

  Examples of the organic halogen compound contained in the insulating oil include PCBs and dioxins, and the kind thereof is not particularly limited. Examples of commercially available PCBs include KC-200 (main component: biphenyl dichloride), KC-300 (main component: biphenyl trichloride), KC-400 (main component: biphenyl tetrachloride) manufactured by Kaneka Chemical Co., Ltd. KC-500 (main component: biphenyl bichloride), KC-600 (main component: biphenyl bichloride), Arrochlor 1254 (54% Chlorine) manufactured by Mitsubishi Monsite Corporation, and the like.

  FIG. 3 is an explanatory diagram illustrating a configuration example of a transformer having a capacity of 1000 L (excluding a pole transformer). The transformer 1 (outer dimension: about 65 cm × 85 cm × 190 cm) is provided with a radiator 4, and the radiator 4 is connected to the transformer (connected or welded with a flange) at two upper and lower portions 2 and 3. The distance from connection point 3 to the upper end of the transformer is about 20 cm. In the transformer container, iron plates 12 and 15 and an iron frame 13 are installed, in which an internal member (coil) 14 having a volume of about 130 to 200 L is installed, and in the coil, insulating paper (not shown), There is a piece of wood. There is a drain valve 17 at the bottom of the transformer. Although only one radiator 4 is shown in FIG. 3, each radiator is attached to each of the four side surfaces of the transformer by a flange, and the total volume of the four radiators is 240 L in total.

  FIG. 4 is a diagram illustrating a state where the radiator is removed from the transformer of FIG. 3.

  FIG. 5 is an explanatory diagram for explaining a configuration example of a transformer having a capacity of 10,000 L (excluding a pole transformer). In the container of the transformer 21 (outside dimension: about 1600 cm × 5500 cm × 2000 cm) Three internal members (coils) 24 similar to a 1000 L class transformer are installed, and insulating paper and wood pieces (not shown) are present in the coils. A radiator 26 is connected to both sides. There is a drain valve 27 at the bottom of the transformer.

  The transformer 1 and the transformer 21 having different capacities have a configuration in which the shape of the internal member (coil) is substantially the same (similar) and the number of internal members (coils) is different. Therefore, the capacity | capacitance of the transformer 21 is large by the part which has a large bottom area. Since the residual oil amount B remaining in the transformer after draining the insulating oil is proportional to the bottom area and the wall area of the transformer, even if the capacity of the transformer is different, the ratio of the residual oil amount B to the transformer capacity A ( B / A) is a substantially constant value.

  Similarly, the residual oil amount B remaining in the transformer after draining the insulating oil is proportional to the bottom area of the transformer, so that even if the capacity of the transformer is different, the capacity of the cleaning liquid filled in the transformer after draining the insulating oil If the ratio of C to the residual oil amount B (C / B) is equal, the cleaning liquid is filled to the height of almost the same ratio.

(Draining insulation oil)
As a method of extracting insulating oil from a transformer, generally, a method of discharging from a drain valve (another name: draining the oil outlet), a method of pumping out by a pump (another name: upper pumping), an overturning method (another name: tilting) Drainage). Since it is difficult to tilt and drain oil with a large transformer, and the pumping method makes the work complicated, the method of discharging from the drain valve (17 in FIG. 3, 27 in FIG. 5) is the most common. . In the present invention, a method of discharging from the drain valve, and further, a method of additionally using a method in which the transformer is inclined obliquely with the drain valve facing downward so that the drain valve discharges as much as possible. Is suitable.

  In the case of transformers other than pole transformers, the internal structure is not as complex as pole transformers, but oil that has penetrated into the gaps of internal parts and oil that has penetrated into insulating paper and wood pieces even after draining insulation oil is completely removed. Therefore, when the capacity B of the residual oil remaining in the transformer after extraction is expressed as a ratio (B / A) to the capacity A of the transformer, in the discharge method from the drain valve, usually 0.01 <B / A ≦ 0.2. The reason why B / A exceeds 0.01 in the discharge method from the drain valve is because the attachment position of the drain valve is structurally several cm above the bottom surface of the transformer. In addition, if B / A exceeds 0.2, the amount of residual oil becomes too large, and there is a possibility that the internal member cannot be rendered harmless by filling the cleaning liquid once. However, in the discharge method from the drain valve, Usually, the position of the drain valve is unlikely to be higher than 20% of the height of the device from the bottom of the device, and therefore does not exceed 0.2. However, depending on the extraction method of the insulating oil, the ratio (B / A) of the residual oil amount B to the transformer capacity A can be set to 0.01 <B / A ≦ 0.05. If the amount is small, a relatively large amount of cleaning liquid can be filled, which is preferable for shortening the processing time. The capacity B of the residual oil can be obtained as a difference between the amount of the contaminated insulating oil that has entered the transformer and the amount of the extracted insulating oil. By the way, in most cases, the liquid level of the residual oil is lower than the bottom side attachment portion of the radiator.

(Filling with cleaning solution)
After draining insulation oil, 0.01 to 2.0% by weight of alkali is contained in the transformer whose residual oil amount is 1 to 20% (preferably 1 to 5%) of the original transformer capacity. The cleaning liquid composed of the isopropyl alcohol solution is filled so that the volume C of the cleaning liquid satisfies 4 ≦ C / B ≦ 60. At this stage, residual oil (capacity B) and cleaning liquid (capacity C) are contained in the transformer (or transformer + radiator). When the addition ratio (C / B) of the cleaning liquid is less than 4, the internal member is not completely immersed in the cleaning liquid, and thus the internal member that does not come into contact with the cleaning liquid may not be rendered harmless. Moreover, when the addition ratio (C / B) of a washing | cleaning liquid exceeds 60, it cannot accommodate in the container of a transformer and will overflow.

  As shown in FIG. 1, in the case where the cleaning liquid is circulated and cleaned with a radiator, as much cleaning liquid as is required to enter the transformer is required, so that the capacity C of the cleaning liquid is 5 ≦ C / B ≦. 60 is preferably filled, and more preferably 20 ≦ C / B ≦ 60.

  As shown in FIG. 2, when the cleaning liquid is circulated and cleaned without a radiator, an extra cleaning liquid is required as long as the cleaning liquid enters the radiator, so the capacity C of the cleaning liquid is 4 ≦ C / B ≦. 50 is preferably filled, and more preferably 10 ≦ C / B ≦ 50.

  Isopropyl alcohol is used as the solvent constituting the cleaning liquid. This isopropyl alcohol serves as a solvent for dissolving the organic halogen compound and serves as a hydrogen donor during the decomposition of the organic halogen compound.

  The alkali constituting the cleaning liquid is preferably KOH or NaOH from the viewpoint of high dehalogenation efficiency and excellent cost and handling properties. An alkali is used individually or in combination of 2 or more types. Alkali serves as a neutralizing agent that neutralizes chlorine released by the decomposition of the organic halogen compound. Therefore, even if the amount of the neutralizing agent is too large, it is inferior in economic efficiency, and if it is too small, the reaction rate decreases. .

  The amount of alkali is stoichiometrically determined from the amount of residual oil B in the pole transformer and the concentration of the organic halogen compound in the residual oil to determine the amount of the organic halogen compound in the transformer. However, it is considered that 1.0 to 1.5 times the equivalent of isopropyl alcohol should be contained in the isopropyl alcohol, but in reality, the concentration is too low to cause the reaction to proceed. Therefore, in consideration of the knowledge obtained by processing the low-concentration PCB-mixed oil and the fact that the residual oil is diluted 70 to 170 times as the reaction liquid in the container processing, the alkali during the container processing is 1 to 1 of the residual oil amount. 20% by weight is preferably added. The alkali concentration in the cleaning liquid when so prepared is usually 0.01 to 2.0% by weight. When the alkali concentration is less than 0.01% by weight, the reaction rate decreases, and when it exceeds 2.0% by weight, the reaction rate does not increase and reaches a peak. Considering economic efficiency, post-treatment of the cleaning liquid, etc., the more preferable alkali concentration is 0.01 to 1.5% by weight, and the most preferable alkali concentration is 0.02 to 0.5% by weight.

The following (Table 1) shows an example of the composition of the cleaning liquid when a predetermined amount of cleaning liquid is filled with respect to the oil amount and capacity of the transformer and the residual oil amount. From Table 1, when the amount of residual oil is within a certain range, it is possible to immerse the internal member in the cleaning liquid if the cleaning liquid is filled within the certain amount range, and the alkali concentration ( It can be seen that the alkali concentration is substantially equal to the alkali concentration in the whole liquid), which is also within the range of 0.01 to 2.0% by weight.
On the other hand, if the amount of cleaning liquid is too small relative to the residual oil, the upper part of the coil of the internal member cannot be immersed in the cleaning liquid (No. 1). If the amount of cleaning liquid is too large, the cleaning liquid can be removed from the transformer container. May overflow (No.6, 7).

(Circulation cleaning)
Next, the cleaning liquid in the transformer is circulated and cleaned in the transformer while being passed through the catalyst filling device, and alkali is added at an appropriate time so that the alkali concentration is maintained in the range of 0.01 to 2.0% by weight. Prior to the circulation cleaning, the cleaning liquid may be circulated in the transformer for several days in advance by the pump 11 to elute the PCB in the internal member. When the cleaning liquid filled in the transformer starts to circulate through the pump 5 to circulate and wash the catalyst filling device, it also enters the radiator 4 (only when there is a radiator), piping and the catalyst filling device 7. The amount of cleaning liquid in the pole transformer is reduced. At this time, it is most preferable to adjust the amount of the cleaning liquid so that the height is slightly lower than the upper connection portion 2 of the radiator in view of the economy of the cleaning liquid and detoxification of the internal members (see FIG. 3). ). For the same reason, in the case of a transformer with a capacity of 10,000 L (excluding a pole transformer), as shown in FIG. Most preferably, it is filled.

  After adjusting the amount of the cleaning liquid in the transformer, as shown in FIG. 1 or FIG. 2, the cleaning liquid in the pole transformer is passed through the pump 5 and the catalyst filling device 7 installed in the microwave device 6. To supply. Although not shown in part in the catalyst filling device 7 shown in FIGS. 1 and 2, a catalyst packed layer filled with a catalyst capable of decomposing an organic halogen compound is formed. As shown by the arrows in the figure, the cleaning liquid is introduced into the catalyst filling device 7 via the pump 5 and the supply line, and the introduced cleaning liquid flows through the catalyst packed bed and then temporarily returns to the return tank 8 via the recovery line. Here, after the gas in the cleaning liquid is discharged, it is returned to the transformer 1 through the pump 9.

  The catalyst filled in the catalyst filling device is not limited as long as it can accelerate the dehalogenation reaction of an organic halogen compound (particularly PCB). However, an inorganic catalyst has a long catalyst life and is in the presence of an alkali compound. However, since it is stable, it is preferable to an organic catalyst. As the inorganic catalyst, composite metal oxides, carbon crystal compounds, metal-supported carbon compounds, metal-supported oxides, metal-supported composite metal oxides, metal oxides, and the like are preferably used from the viewpoint of increasing dehalogenation efficiency. Among these, from the viewpoint of high stability in an alkaline atmosphere, a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, and a metal-supported composite oxide are preferable, and a metal-supported carbon compound is particularly preferable. These catalysts can be used alone or in any combination of two or more, and a regenerated catalyst may be used.

  The metal-supported carbon compound may be a carbon compound supporting a metal, and the amount of the metal supported is 0.1 to 20 wt%, more preferably 0.1 to 10 wt% with respect to the total amount of the catalyst. Examples of the supported metal include iron, silver, platinum, ruthenium, palladium, rhodium, and the like. From the viewpoint of increasing the dehalogenation efficiency, palladium, ruthenium, and platinum are preferable, and palladium is particularly preferable. Specific examples of the metal-supported carbon compound include Pd / C (palladium-supported carbon compound), Ru / C (ruthenium-supported carbon compound), and Pt / C (platinum-supported carbon compound). A catalyst in which a metal is supported on a resin such as polyethylene can be used as long as it is stable in the presence of an alkali compound.

  The shape of the catalyst may be granular or honeycomb. In the case of granular, it is necessary to fix the upper and lower sides of the column with a mesh or the like, and the particle diameter in that case is preferably 75 μm to 10 mm. When it exceeds 10 mm, the specific surface area is insufficient, and when it is less than 75 μm, the mesh is clogged and the differential pressure becomes high. More preferably, it is 150 μm to 5 mm. The catalyst particles should have the same particle size as possible.

  The circulating cleaning is preferably performed continuously for a predetermined time in a state where the cleaning liquid is circulated while flowing through the catalyst filling device, but may be performed intermittently. Meanwhile, the progress of the reaction can be confirmed by appropriately measuring the concentration of the organic halogen compound in the cleaning solution. The circulation cleaning is performed until the organic halogen compounds remaining in the internal members satisfy predetermined graduation standards. The liquid temperature during washing is preferably from room temperature to 60 ° C. This is because the decomposition time of organic halides is slow at room temperature or lower, so that the treatment time becomes longer, and when it exceeds 60 ° C., by-products and dioxins are easily generated.

  The circulating cleaning is preferably performed continuously for a predetermined time in a state where the cleaning liquid is circulated while flowing through the catalyst filling device, but may be performed intermittently. Meanwhile, the progress of the reaction can be confirmed by appropriately measuring the concentration of the organic halogen compound in the cleaning solution. The circulation cleaning is performed until the organic halogen compounds remaining in the internal members satisfy predetermined graduation standards. The liquid temperature during washing is preferably from room temperature to 60 ° C. This is because the decomposition time of organic halides is slow at room temperature or lower, so that the treatment time becomes longer, and when it exceeds 60 ° C., by-products and dioxins are easily generated.

  Further, in the detoxification method of the present invention, after measuring the alkali concentration in the cleaning solution at an appropriate time, for example, at intervals of 1 to 24 hours, an alkali is additionally added as necessary, and the alkali maintains a predetermined concentration. Like that. This is because the alkali is gradually consumed with the decomposition of the organic halogen compound, and therefore, when the alkali concentration is lowered, the decomposition rate of the organic halogen compound is reduced, and a rapid treatment cannot be performed. Since the alkali concentration in the cleaning liquid and the alkali concentration in the liquid are substantially equal (see Table 1), the measurement of the alkali concentration in the cleaning liquid can be changed by measuring the alkali concentration in the liquid. Although there is no limitation in the measuring method of alkali concentration, it can obtain | require by titration using normal hydrochloric acid, for example. The alkali concentration is always in the range of 0.01 to 2.0% by weight, more preferably in the range of 0.01 to 1.0% by weight, particularly preferably 0 in consideration of dechlorination efficiency and economy. It is good to keep in the range of 0.02 to 0.5% by weight.

  When the cleaning liquid is circulated through the catalyst filling device, the decomposition of the organic halogen compound can be promoted by irradiating the cleaning liquid with microwaves using the microwave irradiation device 10 in the catalyst filling device. The microwave may be irradiated continuously or intermittently. In this case, the output and frequency of the microwave can be determined as appropriate according to the cleaning conditions to be set. However, the microwave having a frequency of 1 to 300 GHz can be irradiated in the range of 10 W to 20 kW while being electrically controlled. preferable. Also in this case, the liquid temperature at the time of washing is preferably from room temperature to 60 ° C.

  By circulating the organohalogen compound remaining in the internal member until the graduation standard is satisfied by the above method, the internal member can be rendered harmless.

  After completion of the cleaning process, the cleaning liquid is drawn up from the transformer by a pump, and as shown in the flowchart of FIG. 6, the transformer is dried and then disassembled into an iron container (case) and an internal member. The disassembled container (case) is disassembled into containers (cases) and insulators, etc. The internal members are disassembled into iron cores and coils (copper wires), and the coils are crushed and then disassembled into copper and paper / wood. To do. It is confirmed by analysis whether each disassembled member satisfies a predetermined graduation standard value for each member. Thereafter, the member is recycled.

  According to the detoxification treatment method of the present invention, the internal member can be detoxified before dismantling the transformer, but after the detoxification treatment of the internal member of the transformer, If the value is not satisfied, further cleaning may be performed using a conventionally known cleaning method.

  Moreover, when performing the detoxification process according to the present invention, there is a risk that the inner upper portion of the transformer container where there is no internal member may be insufficiently cleaned. You may use together.

  The method for detoxifying an organic halogen compound-containing transformer internal member of the present invention is useful as a treatment method for detoxifying an internal member of a large transformer (excluding a pole transformer) containing PCB.

It is the schematic which shows one Embodiment of the detoxification processing method of the organic halogen compound containing transformer internal member which concerns on this invention. It is the schematic which shows one Embodiment of the detoxification processing method of the organic halogen compound containing transformer internal member which concerns on this invention. It is explanatory drawing which shows the structural example of a 1000L class transformer (except for a pole top transformer). It is explanatory drawing which shows the structural example which removed the radiator from the 1000L class transformer (except pole transformer). It is explanatory drawing which shows the structural example of a 10,000 L class transformer (except a pole top transformer). It is a flowchart which shows the process example of a pole transformer by the detoxification processing method of the organic halogen compound containing transformer internal member of this invention. It is a flowchart which shows the process example of the pole transformer by the detoxification processing method of the conventional organic halogen compound containing transformer internal member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transformer 2,3 Radiator connection location 4 Radiator 5 Pump 6 Microwave apparatus 7 Catalyst filling apparatus 8 Return tank 9 Pump 10 Cleaning liquid storage tank 11 Pump 12 Iron plate 13 Iron frame 14 Internal member (coil)
15 Iron plate 16 Cleaning liquid 17 Drain valve 21 Transformer 24 Internal member (coil)
25 Liquid level of cleaning liquid 26 Radiator 27 Drain valve

Claims (8)

The capacity B of the insulating oil remaining in the transformer after extracting the insulating oil from the transformer (excluding the pole transformer) containing the insulating oil containing a trace amount of the organic halogen compound and having a capacity A of 100 L or more is , 0.01 <B / A ≦ 0.2,
The transformer after draining the insulating oil was filled with a cleaning liquid composed of an isopropyl alcohol solution containing 0.01 to 2.0% by weight of alkali so that the capacity C satisfies 4 ≦ C / B ≦ 60. rear,
While circulating the washing liquid in the transformer through the catalyst filling device and circulatingly washing in the transformer, while adding alkali so that the alkali concentration is kept in the range of 0.01 to 2.0% by weight, Decomposes organic halogen compounds remaining on internal members
A detoxifying treatment method for an organic halogen compound-containing transformer internal member.   2. The method for detoxifying an internal component of an organic halogen compound-containing transformer according to claim 1, wherein the transformer after draining the insulating oil has no radiator and 4 ≦ C / B ≦ 50.   2. The method for detoxifying an internal component of an organic halogen compound-containing transformer according to claim 1, wherein the transformer after draining the insulating oil is provided with a radiator and 5 ≦ C / B ≦ 60.   The organic halogen compound-containing transformer internal member according to claim 1 or 2, wherein the cleaning liquid in the transformer is discharged from the opening on the bottom side after the radiator is removed from the transformer and led to a catalyst filling device. Detoxification treatment method.   The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of claims 1 to 4, wherein the cleaning temperature is from room temperature to 60 ° C.   The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of claims 1 to 5, wherein the alkali is at least one selected from NaOH and KOH.   The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of claims 1 to 6, wherein the catalyst is a palladium-supported carbon compound.   The method for detoxifying an organic halogen compound-containing transformer internal member according to any one of claims 1 to 7, wherein, when the organic halogen compound is decomposed, the cleaning liquid in the catalyst filling device is irradiated with microwaves.