JP2015182046A - Pole-mount transformer treatment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning treatment of a pole-mount transformer using a PCB-containing insulating oil while preventing diffusion of PCB.SOLUTION: A process of reinforcing a seal is performed before a cleaning process.

Description

  The present invention relates to a column transformer processing method for cleaning a column transformer that contains PCB-containing insulating oil therein to reduce the PCB content of the column transformer.

PCB (polychlorinated biphenyl) has been used extensively in insulating oils for electrical equipment such as pole transformers because of its excellent electrical insulation properties. However, its use has been banned in recent years as its harmfulness has been recognized. ing.
Many of the electrical devices using the PCB are collected and stored in a special facility, and the detoxification process is sequentially performed in the facility.

Such a pole transformer is usually a bottomed cylindrical housing with an upper opening, a lid that closes the opening of the housing, a transformer element housed in the housing with PCB-containing insulating oil, It is comprised by the bushing etc. which become the electric current path | route of the said transformer element and the exterior, As a method for detoxifying this pole transformer, for example, a pole transformer as shown in the following patent document 1 is used. A method for separate dismantling is known.
In such a separate dismantling method, a cleaning process is usually performed to remove PCB from the dismantled product.

JP 2006-289288 A

  In the treatment as described above, for the purpose of preventing the PCB from diffusing around in the dismantling operation or the like, the insulating oil containing PCB is extracted from the pole transformer prior to dismantling, and further contains the PCB adhering to the inside. It may be preferable to wash away the insulating oil.

As a method for internally cleaning the transformer on the pillar, for example, an oil or an organic solvent having good compatibility with the PCB-containing insulating oil is used as a cleaning liquid, the cleaning liquid is supplied into the pillar transformer, and the PCB-containing insulating material is combined with the cleaning liquid. A method is conceivable in which oil is discharged from the transformer on the pillar.
In this case, it is considered that the PCB-containing insulating oil adheres inside the pole transformer at least at the level of the PCB-containing insulating oil before the start of processing.
Therefore, when the PCB-containing insulating oil is to be removed by washing as much as possible from the pillar transformer, the pillar transformer is filled with the cleaning liquid.

Although the necessary parts of the transformer on the pole are sealed with a sealing material made of rubber elastic body, etc., the sealing performance may be impaired due to aging deterioration of the sealing material, etc. There is a risk of leaking the PCB-containing insulating oil together with the cleaning liquid from the place.
If it does so, it may have the result of causing the spreading | diffusion of PCB rather.
The present invention has been made in view of such problems, and an object of the present invention is to provide a column transformer processing method capable of detoxifying the column transformer while preventing PCB diffusion.

  In order to solve the above-mentioned problems, the present invention supplies a cleaning liquid to the inside of a pole transformer in which insulating oil containing PCB is accommodated, and discharges the insulating oil together with the cleaning liquid from the pole transformer, thereby the pole transformer. A column-top transformer processing method for carrying out a cleaning process for reducing the PCB content of the substrate, wherein the column-top transformer has a bottomed cylindrical casing having an upper opening and a lid for closing the opening of the casing. An annular sealing material is interposed between the housing and the lid so as to surround the opening, and a lid opening step for opening the lid of the pole transformer, the opened lid and the annular A new annular sealing material is interposed between the sealing material or between the annular sealing material and the housing, and the lid is reattached to the housing to improve the sealing performance at the opening before the opening process. Reinforcement of seal to strengthen compared to Providing pole transformer processing method which comprises carrying out the bets before the washing step.

In the on-column transformer processing method of the present invention, the cleaning liquid is supplied to the inside of the on-column transformer to perform internal cleaning.
In addition, since the internal cleaning of the on-pillar transformer is performed after enhancing the sealing performance, leakage of the PCB-containing insulating oil during internal cleaning can be suppressed.
That is, according to the present invention, the pole transformer can be made harmless while suppressing the diffusion of PCB.

Schematic which shows a pole transformer. (A) The schematic perspective view of a rubber bushing, (b) The attachment figure to a lid | cover. (A) The schematic perspective view which showed a mode that a new cyclic | annular sealing material was installed, and (b) schematic plan view. (A) The schematic which showed the setting method of the washing | cleaning-liquid supply pipe | tube, (b) The principal part enlarged view. The schematic sectional drawing which showed a mode that a new cyclic | annular sealing material was installed. (A) The schematic side view which showed a mode that round rubber was arrange | positioned on a flange part, (b) The schematic top view which showed a mode that FIG. 6 (a) was seen from the block arrow "a" direction. (B) The schematic side view which showed a mode that board rubber was arrange | positioned in the flange part, (b) The schematic top view which showed the mode which looked at Fig.7 (a) from the block arrow "a" direction.

Hereinafter, preferred embodiments of the present invention will be described (based on the accompanying drawings).
First, a pole transformer that is detoxified by the pole transformer processing method of the present embodiment will be described with reference to FIG.

FIG. 1 is a schematic front view showing the structure of a pole transformer. As shown in the figure, a pole transformer 100 according to this embodiment includes a bottomed cylindrical casing 110 having an upper opening, And a lid 120 that closes the opening 111 of the housing 110.
The columnar transformer 100 of this embodiment further includes a clamp 130 for fixing the lid 120 to the housing 110.
The clamps 130 are arranged at substantially equal intervals in the direction of circling the opening 111. In the present embodiment, the clamps 130 are provided at a total of four locations every 90 degrees.
Further, the pole transformer 100 accommodates a transformer element 140 configured by using a coil and a core material and a PCB-containing insulating oil A inside the casing 110.
Furthermore, the pole transformer 100 includes a bushing 150 for making an electrical connection to the transformer element 140 from the outside.

The casing 110 includes a vertical cylindrical side wall portion 112 and a bottom wall portion 113 that closes the side wall portion 112 at its lower end, and the opening 111 is defined by the upper end of the side wall portion 112.
That is, the housing 110 of the present embodiment has an opening 111 having a circular shape in plan view.
The casing 110 is provided with a flange portion 114 that extends horizontally outward from the upper end of the side wall portion 112 and has an outer edge that is circular with a diameter larger than that of the opening 111. .
The flange portion 114 in the present embodiment is formed so that the shape in plan view is an annular shape and the width in the system direction is substantially constant in the circumferential direction.
Further, the casing 110 in this embodiment has a circular opening 115 (side wall opening 115) slightly above the center in the height direction of the side wall 112, and the bushing is formed in the opening 115. 150 is inserted.

The lid 120 includes a disc-shaped lid body 121 that is slightly larger than the circle defined by the outer edge of the flange portion 114, and a hanging wall portion 122 that hangs down from the outer periphery of the lid body 121, and the hanging wall The cover body 121 is externally fitted to the housing 110 such that the lower surface of the lid body 121 inside the portion 122 faces the flange portion 114.
In the pole transformer 100, an annular sealing material 160 having a slightly narrower width than the flange portion 114 of the housing 110 is interposed between the flange portion 114 and the lid main body 121.

The bushing 150 has a round bar shape as a whole, with one end in the longitudinal direction being thick enough to be inserted into the side wall opening 115 and the other end being thicker than the side wall opening 115.
That is, the bushing 150 is provided with a stepped portion 151 at an intermediate position from one end side to the other end side in the longitudinal direction. The large-diameter portion 153 has a large thickness.
The bushing 150 is provided in the pole transformer 100 such that the small diameter portion 152 is disposed in the internal space of the columnar transformer 100 and the large diameter portion 153 is disposed in the external space.
That is, the pole transformer 100 is provided with the bushing 150 in such a manner that a step 151 is brought into contact with the periphery of the side wall opening 115, and an inner diameter is provided between the step 151 and the side wall 112. An annular sealing material 170 having substantially the same diameter as the side wall opening 115 is interposed.

In the pole transformer 100, the transformer-containing element 140 is completely immersed, and the PCB-containing insulating oil A is accommodated therein.
Therefore, after removing the PCB-containing insulating oil A, the pole-mounted transformer 100 normally has at least the PCB-containing insulating oil A adhered to the inner surface of the casing until the level of the PCB-containing insulating oil A before extraction. doing.
Therefore, when the column transformer 100 is internally cleaned, the cleaning liquid is preferably supplied into the column transformer above the liquid level, and the column transformer is preferably filled with the cleaning liquid.

  As described above, the columnar transformer 100 according to the present embodiment is configured such that the gap between the flange portion 114 of the housing 110 and the lid main body 121 is sealed by the annular seal material 160 as a seal portion for sealing the internal space from the outside. 1 seal portion, and a second seal portion in which the space between the bushing 150 and the side wall portion 112 of the housing 110 is sealed by an annular seal material 170.

Here, the annular seal members 160 and 170 in the first seal part and the second seal part normally exhibit sealing properties by their elastic restoring force, but are on the pillars collected for detoxification treatment. In many transformers, the sealing material is also hardened and deformed so that sufficient sealing performance cannot be exhibited.
Therefore, for example, even if the abutting force between the lid 120 and the housing 110 is increased by tightening the clamp 130 or the like, the abutting force is not sufficiently reached between the clamps, and the pillar transformer is filled with the cleaning liquid. Then, the PCB may leak together with the cleaning liquid at any location.

Therefore, in the present embodiment, the seal strengthening step is performed before the internal cleaning of the pole transformer is performed as described below.
Hereinafter, a method for internally cleaning the column transformer will be described.
Specifically, the on-column transformer processing method of the present embodiment can be implemented by the following steps (a) to (e).

(A) Lid opening process First, the fixing of the casing 110 and the lid 120 by the clamp 130 is released, the lid 120 is removed, and the internal state of the pole transformer 100 and the state of the annular seal material 160 are confirmed.
The annular sealing material 160 is usually attached to either the lid side or the housing side (on the flange portion) when the lid is opened, and in many cases, the whole is attached to the lid side. ing.
As will be described later, in this embodiment, a new annular sealing material is interposed between the annular sealing material 160 and the lid 120 or between the annular sealing material 160 and the housing 110 (flange portion 114). Therefore, in this process, the position where the new annular sealing material is interposed is determined.
That is, when the annular sealing material 160 is attached to the lid side, the new annular sealing material is placed at the old annular sealing material so that the new annular sealing material can be easily inserted. It is determined between the material 160 and the flange portion 114.
Further, when the annular sealing material 160 adheres to the flange portion when the lid is opened, a new annular sealing material interposition position is determined between the old annular sealing material 160 and the lid 120.

(B) Cleaning Liquid Supply Port Formation Step Next, a through hole (cleaning liquid supply port) for supplying the cleaning liquid into the columnar transformer is formed in the lid 120 or the housing 110.
The opening shape of the through hole is not particularly limited, but the opening shape is preferably circular in that it can be easily formed by a drill, a hole saw or the like.
Further, when the through hole is formed by a drill or a hole saw, it is preferable to carry out a deburring operation around the through hole separately.
At this time, if chips or the like are mixed in the PCB-containing insulating oil A, the chips are later discharged in the step of discharging the PCB-containing insulating oil A to the outside of the column transformer or the step of cleaning the inside of the column transformer. There is a possibility that it may be adversely affected if mixed into piping or pumps for transporting PCB-containing insulating oil or cleaning oil.
Therefore, it is preferable to form the cleaning liquid supply port for the removed lid 120.

The cleaning liquid supply port may be used as a cleaning liquid discharge port for discharging the cleaning liquid supplied to the inside.
That is, in the present embodiment, since the cleaning liquid supply port and the cleaning liquid discharge port can be used together, the lid 120 may be provided with only one through hole.
However, if the cleaning liquid supply port and the cleaning liquid discharge port are used in common, there is a risk of many restrictions in the cleaning operation.
Therefore, in the present embodiment, it is preferable to provide two or more through holes in the lid 120 so that the cleaning liquid supply port and the cleaning liquid discharge port are formed by separate through holes.

(C) Seal strengthening process Since the cleaning liquid supply port and the cleaning liquid discharge port provided in the above process are not equipped with any member that exhibits sealing performance, the annular sealing materials 160 and 170 have sufficient sealing performance. Even when this is achieved, the cleaning liquid may leak from the cleaning liquid supply port and the cleaning liquid discharge port when the column top transformer is filled with the cleaning liquid.
Accordingly, in the seal strengthening step, a sealing material such as a rubber bushing is attached to the cleaning liquid supply port and the cleaning liquid discharge port, and the third seal portion is supplied to the cleaning liquid after the opening 111 and the side wall opening 115. It is preferable to form it at the mouth or the cleaning liquid outlet.

As the rubber bushing for sealing the third seal portion, for example, the one shown in FIG. 2 can be employed.
FIG. 2 is a schematic perspective view of the rubber bushing 200 and a mounting view schematically showing how the rubber bushing 200 is mounted in the cleaning liquid supply port 125 provided in the lid 120.
As shown in this figure, the rubber bushing 200 of the present embodiment has a flat cylindrical shape and has a through hole 201 that penetrates along the central axis, and a circumferential groove 202 that circulates around the axis on the outer periphery. Have.
The circumferential groove 202 is for locking the rubber bushing 200 to the opening edge of the cleaning liquid supply port 125 when the rubber bushing 200 is inserted into the cleaning liquid supply port 125 as shown in the figure.
Therefore, in the rubber bushing 200 of the present embodiment, the outer diameter at the portion where the circumferential groove 202 is formed is substantially the same as or slightly larger than the diameter of the cleaning liquid supply port 125, and the other part is the cleaning liquid supply port. The diameter is much larger than the diameter of 125.
Further, the through hole 201 of the rubber bushing 200 is for inserting a tube through which the cleaning liquid is circulated as described later.

When this rubber bushing 200 is attached to the cleaning liquid supply port 125, the elastic restoring force of the rubber bushing 200 outward in the radial direction affects the sealing performance with the lid 120.
Here, the shape of the opening edge of the cleaning liquid supply port 125 is not necessarily matched with the shape of the rubber bushing 200.
Accordingly, it is preferable that the rubber bushing 200 is filled with grease or the like in the circumferential groove 202 in order to exhibit the sealing performance by another mechanism in addition to the sealing performance by the elastic restoring force.
As this grease, those having a small “consistency” (JIS K2220) to some extent (“consistency number” being large) are preferable, and those having a “consistency” of about 200 to 300 are preferable.
The grease used for reinforcing the seal of the rubber bushing 200 is preferably oil resistant, and vacuum grease or the like is preferably used.
As for the cleaning liquid discharge port, it is preferable to attach a rubber bushing similarly to the cleaning liquid supply port 125 and to reinforce the seal with vacuum grease or the like.

The lid 120 fitted with the rubber bushing 200 as described above is fixed to the housing 110 again for the internal cleaning of the pole transformer 100.
However, in the present embodiment, it is preferable to enhance the sealing performance between the housing 110 and the lid 120 (first seal portion) before the lid 120 is fixed to the housing 110.
Regarding the sealability of this portion, since the annular sealing material 160 usually has largely lost its function, it is conceivable to replace the annular sealing material 160 with a new one.
However, when the annular sealing material 160 is fixed to the lid 120 or the flange portion 114 of the housing 110, it may take a lot of trouble to remove the old annular sealing material 160.
Therefore, with respect to the seal reinforcement of this portion, for example, as shown in FIG. 3, an annular seal member 180 different from the old annular seal member 160 is provided between the old annular seal member 160 and the flange portion 114, or the old annular seal member. It can be implemented by newly inserting between the material 160 and the lid 120 and increasing the number of fixing points by the clamp 130.
The new annular sealing material 180 does not need to have the same shape and thickness in plan view as the old annular sealing material 160, and as shown in FIG. The shape is not particularly limited as long as the hatched area in the middle is a ring surrounding the upper opening of the housing 110.
However, as the new annular sealing material 180, it is preferable to adopt a material having a lower elastic modulus than the old annular sealing material 160.
More specifically, the new annular sealing material 180 is preferably made of a material having easy deformability such as a rubber foam.

Between the new annular seal material 180 and the old annular seal material 160, for example, grease or the like, similar to the technique used for enhancing the sealing performance of the third seal portion between the rubber bushing 200 and the lid 120, etc. It is possible to improve the sealing performance by applying the coating.
Further, even when the old annular sealing material 160 is fixed to the lid 120 or the flange portion 114, a gap may be formed between them. Alternatively, a liquid adhesive having a low viscosity and a high penetrating power may be infiltrated and solidified between the annular sealing material 160 and the flange portion 114 to further enhance the sealing performance.
Examples of the liquid adhesive having excellent permeability include an instantaneous adhesive mainly composed of cyanoacrylate and an anaerobic adhesive.

The shape of the new annular sealing material 180 is particularly suitable if it can secure an annular surface contact region surrounding the upper opening of the housing 110 with the existing annular sealing material 160 as described above. Although not limited thereto, there is a large difference in shape between the mating material (for example, the existing annular seal material 160 and the flange portion 114 of the housing 110) that comes into contact with the new annular seal material 180 when it is set. When it has, there exists a possibility that the positioning for making the said surface contact area | region may become difficult.
Therefore, it is preferable that the new annular sealing material 180 has a shape substantially the same as that of the old annular sealing material 160 or the flange portion 114.

Further, it is preferable that the new annular sealing material 180 secures a contact area as large as possible with the existing annular sealing material 160.
Therefore, it is preferable that the new annular sealing material 180 has a shape that covers the entire upper surface of the flange portion 114 when the existing annular sealing material 160 is attached to the lid 120.
That is, as shown in FIG. 5, the new annular sealing material 180 has an inner diameter (D1) slightly smaller than the diameter (D2) of the opening edge of the housing 110 (for example, −2 mm to −5 mm in diameter). It is preferable that
Thus, by setting the inner diameter of the new annular sealing material 180 to be slightly smaller than the opening edge, when the lid 120 is closed again after the installation of the new annular sealing material 180, the annular sealing material 180 is unexpectedly expected. Even if the positional deviation occurs, the effect of ensuring a sufficient contact area with the flange portion can be exhibited.
On the other hand, when the new annular sealing material 180 has such a large outer diameter that it protrudes outward from the outer edge of the flange portion 114, the protruding portion interferes with the hanging wall portion 122 of the lid 120. On the contrary, there is a possibility that the sealing performance is impaired.
Therefore, it is preferable that the new annular sealing material 180 has an outer diameter that is the same as or slightly smaller than the outer diameter of the flange portion 114 (for example, ± 0 mm to −5 mm in diameter).
In this way, by setting the inner diameter of the new annular sealing material 180 to be equal to the outer peripheral diameter of the flange portion 114, when the lid 120 is closed again after the installation of the new annular sealing material 180, the annular sealing material 180 is temporarily expected. Even if a misalignment occurs, the outer edge portion of the annular seal member 180 can be brought into contact with the inner surface of the hanging wall portion 122 of the lid quickly and the effect of preventing any further misalignment can be exhibited.

  And about the extension of the clamp in this 1st seal | sticker part, it is preferable to make a clamp fixing | fixed part equal in the circumferential direction, for example, the clamp fixing | fixed part before sealing reinforcement | strengthening is the opening 111 as mentioned above. In the case where there are four places every 90 degrees in the direction of turning around, it is preferable that these are six places every 60 degrees or eight places every 45 degrees.

About the 2nd seal part between the said bushing 150 and the side wall part 112 of the housing | casing 110, it is difficult to insert a new annular sealing material like said 1st seal part.
Therefore, the first seal portion is exemplified between the annular seal material 170 and the side wall portion 112 and / or between the annular seal material 170 and the bushing 150 (stepped portion 151). Thus, it is preferable to enhance the sealing property by penetrating and solidifying a liquid adhesive (for example, instantaneous adhesive) having excellent permeability.

(D) Cleaning liquid supply pipe installation process After reinforcing the seal as described above, a cleaning liquid supply pipe 300 having a thickness that fits the through hole 201 of the rubber bushing 200 is prepared to form a cleaning liquid supply path. This is inserted through the through hole 201 of the rubber bushing 200 attached to the cleaning liquid supply port 125 as shown in FIG.
The position at which the cleaning liquid supply pipe 300 is set at this time is not particularly limited. However, from the viewpoint of cleaning properties in the pole transformer, the supply point of the cleaning liquid is the case 110. It is preferable to set it at a position close to the bottom wall portion 113.
Accordingly, it is preferable to employ a cleaning liquid supply pipe 300 that is longer than the length from the lid 120 to the bottom wall 113.
Further, the cleaning liquid discharge pipe 400 can also be attached to the lid 120 via the rubber bushing 200 at the cleaning liquid discharge port 126 and set at a predetermined position of the pole transformer 100.

  Note that the pillar transformer 100 of this embodiment can be cleaned internally after the PCB-containing insulating oil A is drained through the cleaning liquid supply pipe 300 or the like, for example.

(E) Cleaning Step When cleaning the columnar transformer 100, the cleaning liquid is supplied into the columnar transformer 100 through the cleaning liquid supply pipe 300, and the PCB-containing insulating oil is supplied through the cleaning liquid discharge pipe 400 together with the cleaning liquid. A method of discharging from the pole transformer 100 can be employed.
At this time, the supply / discharge of the cleaning liquid may be performed continuously or batchwise.
That is, in the cleaning process in the present embodiment, the cleaning liquid may be discharged from the columnar transformer in parallel while supplying the cleaning liquid into the columnar transformer. Instead of such a continuous method, for example, The column-top transformer is filled with a cleaning solution for a certain period of time, and the PCB-containing insulating oil that has entered the narrow space during this period is extracted with the cleaning solution. After the PCB-containing insulating oil is sufficiently extracted, the cleaning solution is discharged. It is possible to employ such a batch method.
In the case of this batch type method, it is possible to perform cleaning for a plurality of cycles for one columnar transformer, with cleaning liquid being supplied, leaving for a predetermined time and discharging the cleaning liquid as one cycle.

Further, when the cleaning process is performed on the plurality of transformers on the pillar, the cleaning liquid can be cascaded.
That is, in the case of the batch type, the cleaning liquid after being left in the first column-top transformer for a predetermined time is transferred to the second column-top transformer and used for the first cleaning of the second column-top transformer. The first column-top transformer is filled with new cleaning liquid, and after a predetermined time has passed, the cleaning liquid from the second column-top transformer is transferred to the third column-top transformer, The cleaning liquid discharged from the first columnar transformer may be supplied again to the eye column transformer so that the used cleaning liquid is sequentially used.
In the case of a continuous type, the cleaning liquid discharge pipe 400 of the first columnar transformer is connected to the cleaning liquid supply pipe 300 of the second columnar transformer, and the cleaning liquid of the second columnar transformer is connected. The discharge liquid 400 is connected to the cleaning liquid supply pipe 300 of the third pillar transformer, and the cleaning liquid supplied to the first pillar transformer is the second pillar transformer, the third pillar transformer, etc. It is only necessary to flow down in order.

In addition, as a washing | cleaning liquid utilized in this washing | cleaning process, insulating oil, petroleum naphtha, liquid paraffin etc. are mentioned, for example.
A sodium dispersion in which metal sodium particles are dispersed in an insulating oil or the like can also be used as the cleaning oil.

In the present embodiment, the PCB is leaked from the seal portion together with the cleaning liquid because the seal strengthening step is performed to enhance the surging properties of the first to third seal portions before such a cleaning step is performed. Can be suppressed.
Moreover, it becomes easy to employ | adopt the thing which is easy to osmose | permeate to a detail as a washing | cleaning liquid because sealing property is strengthened.
And the time which the washing | cleaning of a column top transformer requires can be shortened by employ | adopting the washing | cleaning liquid excellent in such permeability.
Note that the cleaning process of this embodiment does not necessarily require that the pole transformer is cleaned to a level that passes the graduation determination.

Although no further detailed description will be given here, the method for processing a pole transformer of the present invention is not limited to the above example.
In addition, even matters that are not exemplified above can be adopted in the present invention as long as they are conventionally known in the method of processing a pole transformer, as long as the significance of the present invention is not significantly impaired.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

(First verification)
Using several transformers on the same type of pillar transformers with similar production times and conditions, we evaluated how much the seal reinforcement differs depending on the adhesive used.
In the evaluation, four types of commercially available adhesives “adhesive A” to “adhesive D” shown below were used.
(1) Adhesive A
Instant adhesive mainly composed of cyanoacrylate, which has the lowest viscosity (excellent in permeability) among the four adhesives.
(2) Adhesive B
For repairing epoxy resin adhesives and tanks.
(3) Adhesive C
A hot melt adhesive mainly composed of an ethylene-vinyl acetate copolymer.
(4) Adhesive D
Silicone adhesive for general caulking.

First, the lid of the pole transformer was opened, and the state of the annular sealing material interposed between the lid and the flange portion of the housing was confirmed.
At this time, it was confirmed that the annular sealing material was attached to the lid in all the transformers on the pillar.
Therefore, a new annular sealing material is interposed between the originally mounted annular transformer and the flange portion of the housing, and the lid is closed as before, and the sealing performance of the sealing portion between the lid and the housing is restored. Strengthened.
Next, when “adhesive A” to “adhesive D” were applied from the outside of the seal part at the bushing insertion point, the penetration of the “adhesive A” into the seal part was confirmed. ”,“ Adhesive C ”, and“ Adhesive D ”were not able to be confirmed to be penetrable into the seal portion simply by applying from the outside.
In addition, about "adhesive C", it applied using a glue gun, but when the temperature of the glue gun was set to a high temperature in order to reduce the viscosity of the adhesive, dripping due to gravity was severe and a problem occurred in workability. .

When 10 minutes have passed after applying “Adhesive A”, air is supplied to the interior of the pole transformer applied with “Adhesive A” by a compressor to set the internal pressure to 0.05 MPa (gauge pressure), and then the compressor is stopped. The change in internal pressure was observed with a pressure gauge.
It was confirmed that the internal pressure of 0.05 MPa (gauge pressure) was maintained for 30 minutes or more after the compressor was stopped in the pillar transformer applied with the “adhesive A”.
In addition, the soap solution test examined the presence or absence of internal air leakage at the adhesive application location and the seal between the lid and the case. Air leak could not be confirmed.

When 10 minutes have passed after applying “Adhesive B”, air is supplied to the interior of the pole transformer applied with “Adhesive B” by a compressor to set the internal pressure to 0.05 MPa (gauge pressure), and then the compressor is stopped. The change in internal pressure was observed with a pressure gauge.
In the column transformer with this “Adhesive B” applied, the internal pressure dropped to 0.048 MPa (gauge pressure) after the compressor was stopped, and no air leak was observed between the lid and the case in the soapy water test. Air leakage from the bushing insertion point was confirmed.
The pressure of the transformer on the column to which this “adhesive B” was applied was once released, and “adhesive B” was applied to the bushing insertion point.
When the same test was performed again after securing the curing time of 10 minutes, air leaks were confirmed at a portion different from the previous time at the bushing insertion portion.
When the pressure of the transformer on the column to which the “adhesive B” was re-applied was released again, the “adhesive B” was applied once again to the bushing insertion point, and the same test was performed while ensuring a curing time of 10 minutes. As a result, an air leak was confirmed in another part of the bushing insertion part.

When 20 minutes have passed after applying “Adhesive C”, air is supplied to the inside of the pole transformer applied with “Adhesive C” by a compressor to set the internal pressure to 0.05 MPa (gauge pressure), and then the compressor is stopped. The change in internal pressure was observed with a pressure gauge.
In the pillar transformer applied with the “adhesive C”, the internal pressure dropped to 0.045 MPa (gauge pressure) when about 30 minutes passed after the compressor was stopped.
The soap water test confirmed that this decrease in internal pressure was not caused by an air leak at the seal portion between the lid and the housing.
However, as described above, “adhesive C” has a problem of dripping and is difficult to work.

After ensuring the 1-day curing time after applying "Adhesive D", the same evaluation as before was performed.
As a result, severe air leaks were observed at the bushing insertion points to the extent that the internal pressure of the pole transformer was increased to 0.05 MPa (gauge pressure). After waiting, the “adhesive D” was applied again to the bushing insertion point, and the newly applied “adhesive D” was cured over another day.
After that, although the same evaluation was performed, there was no appearance that the air leak at the bushing insertion point was improved, and no further study was performed.
In this case, it was confirmed by a soapy water test that no air leak occurred in the sealing portion between the lid and the casing.

  As described above, in all the tests, it was confirmed that the sealing performance between the lid and the casing was enhanced by introducing a new annular sealing material.

(Second verification)
Three types of on-column transformers shown in Table 1 below were prepared, in which the annular seal material between the lid and the casing had deteriorated over time.

(2.1 Checking the initial state)
First, when the lid of the three types of pole transformers was opened, the annular seal material between the lid and the casing was attached to the lid, and a dent was found at the location where the flange portion of the casing was in contact. It was a situation where cracks were seen on the surface.
In addition, with respect to the “# 1” pole transformer, a part of the flange portion is distorted, and at the distorted portion, the top surface of the flange undulates vertically with a few millimeters of commas.
The lids of these three types of pole transformers were closed without any new sealing material, and air was supplied to the inside by a compressor, and the internal pressure was raised to 0.05 MPa (gauge pressure). A severe air leak was confirmed.

Thereafter, the lid was opened again, and a silicone sealant was applied to the existing annular sealing material, and then the lid was closed again to increase the internal pressure to 0.05 MPa (gauge pressure).
Here, air leakage was improved in the “# 5” pole transformer, but no improvement was observed in the “# 1” and “# 3” pole transformers.

(2.2 Effect of cord seal material)
"# 3" pillar transformer is narrower than the flange formation width, longer than the circumferential length of the flange portion, the cross-section of the cord rubber (round rubber), and wider than the flange formation width, A long plate-like rubber (plate rubber) slightly shorter than the circumference of the flange portion was prepared.

As shown in FIG. 6, the round rubber 180 x is disposed on the flange portion 114 of the “# 3” pole transformer.
And this round rubber 180x was arrange | positioned so that it might circulate around the opening of a housing | casing, and it was arrange | positioned on the flange part 114 so that the extra length part 180x1 might wrap radially inside and outside.
When the wrap portion of this round rubber 180x was brought into close contact, a silicone sealant was applied, a lid was attached, and the internal pressure of the pole transformer was increased as before, the air leak was not improved.

  In addition, as shown in FIG. 7, the rubber plate 180y is arranged so as to be wound around the outside of the flange portion 114, and the flange portion exposed portion 114x between both ends in the longitudinal direction is filled with clay or the like. When the same test was conducted, the air leak was not improved.

(2.3 Effect of annular seal material and clamp enhancement effect)
An annular sealing material having a planar shape similar to the upper surface shape of the flange portion was cut out from each of the 8 mm thick nitrile rubber plate and the 8 mm thick and 5 mm thick foamed nitrile rubber plate (closed cell property).
In addition, about each annular seal, the abbreviation shown in following Table 2 may be used below.

  First, when “NBR8” was interposed between the existing annular seal material of the “# 1” pole transformer and the flange, the lid was closed again and the internal pressure was adjusted to 0.05 MPa (gauge pressure). Air leakage from the strained part of the part was observed, and the internal air leakage could not be completely prevented.

Next, “NBR (F) 8” is interposed between the existing annular sealing material of the “# 3” pole transformer and the flange portion, the lid is closed again, and the internal pressure is set to 0.052 MPa (gauge pressure). As a result, it was found that no pressure drop was observed for 15 minutes and air leakage could be prevented.
Thereafter, a leak test was performed by continuously increasing the internal pressure to 0.07 MPa (gauge pressure), but no pressure drop was observed for 15 minutes.
Therefore, the internal pressure was further increased to 0.082 MPa (gauge pressure), but no pressure drop was observed for 10 minutes.
Then, when the internal pressure was continuously increased to 0.1 MPa (gauge pressure), the internal pressure began to gradually decrease, and when the compressor was stopped and observed, 0.091 MPa (gauge pressure) and 131 minutes were observed after 11 minutes. Later, the pressure decreased to 0.071 MPa (gauge pressure).

After this test, the “# 3” pole transformer was left for 12 days with “NBR (F) 8” attached.
Then, the lid was opened, “NBR (F) 8” was removed, and the state was confirmed. As a result, indentations were found on the surface of “NBR (F) 8”.
When “NBR (F) 8” in the state where the indentation is formed is mounted on the pillar transformer of “# 3” again and a leak test is performed, the internal pressure is reduced even at 0.052 MPa (gauge pressure). The result was seen.

In “# 3”, the lid and the flange portion are fixed by clamps at four locations in the circumferential direction (every 90 degrees). However, four vises are separately prepared, and the vise is provided between the clamps. The lid and the flange portion were fixed by the above, and the lid and the flange portion were fixed at a total of 8 locations.
Then, even when “NBR (F) 8” having indentations was used, it was confirmed that the leak stopped and the pressure of 0.051 MPa (gauge pressure) could be maintained for 16 minutes.

Next, “NBR (F) 8” newly produced for the “# 1” pole transformer was mounted on the “# 1” pole transformer.
In addition, the mounting location was between the bringe part and the existing annular seal material.
And the air leak test was conducted as before.
This “# 1” pole transformer has clamps attached to four locations every 90 degrees, as in “# 3”. However, the above-mentioned “NBR8” is used only with this attached clamp. Although the air leak was less than that of the previous example, the internal pressure test of 0.05 MPa (gauge pressure) could not completely prevent the air leak.
On the other hand, it was confirmed that the air leak was suppressed when the number of fixing points between the lid and the flange portion was increased by using a vice in the same manner as in the study in “# 3”.

  Furthermore, when "NBF (F) 5" was mounted on the pole transformer of "# 5" and the air leak test was conducted as before, the four clamps attached could not completely stop the air leak. However, in the same manner as in the verifications of “# 1” and “# 3”, four fixing points were added and the lid and the flange portion were fixed every 45 degrees in the circumferential direction, and 0.05 MPa (gauge pressure) was obtained. It was confirmed that the pressure could be maintained for 15 minutes, and subsequently a pressure of 0.071 MPa (gauge pressure) could be maintained for 30 minutes.

From the above results, the introduction of a new annular seal material is more reliable than the case where a new annular seal material is not introduced or a cord-like seal material is used as a new seal material. We were able to confirm that
Even when a new annular seal material is used, an internal pressure test of 0.05 MPa (gauge pressure) can be performed by using an annular seal material made of rubber foam or using a new annular seal material after increasing the number of clamps. It was confirmed from the above examination that it can be passed more reliably.
From the above, it can be seen that it is effective to prevent PCB diffusion from the pillar-shaped transformer by interposing a new annular sealing material between the lid and the housing before cleaning the pillar-shaped transformer. .

100: transformer on pole, 110: housing, 111: opening, 112: side wall, 113: bottom wall, 114: flange, 120: lid, 130: clamp, 140: transformer, 150: bushing, 160 : Annular sealing material, 170: annular sealing material, A: insulating oil containing PCB

Claims (2)

A cleaning process is performed to reduce the PCB content of the on-column transformer by supplying a cleaning solution to the inside of the on-column transformer containing the insulating oil containing PCB and discharging the insulating oil together with the cleaning liquid from the on-column transformer. A transformer treatment method on a pillar,
The pole transformer has a bottomed cylindrical casing having an upper opening and a lid that closes the opening of the casing, and an annular seal is provided between the casing and the lid so as to surround the opening. The material is interposed,
An opening step of opening the lid of the pole transformer;
A new annular sealing material is interposed between the opened lid and the annular sealing material or between the annular sealing material and the housing, and the lid is reattached to the housing to reattach the opening. A seal strengthening step for strengthening the sealing performance as compared with that before the opening step;
Is carried out before the cleaning step.   The casing has a cylindrical side wall part defining the opening by an upper end, and a flange part extending outward in the horizontal direction from the upper end of the side wall part, and the on-pillar transformer includes the flange part and The annular sealing material is interposed between the lid and the lid and the flange portion are clamped at a plurality of locations, and the lid is fixed to the housing. 2. The on-post transformer processing method according to claim 1, wherein the number of clamps is increased when the lid is attached than before the lid opening step.

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