JP4694793B2 - Tank structure - Google Patents

Description

  The present invention relates to a tank structure including a cleaning liquid ejecting unit and a cleaning method thereof, and more particularly to a tank structure capable of cleaning the inside of a tank to which a liquid containing harmful substances adheres and a method of cleaning the inside of the tank by the tank structure.

  A casing (container) of an electric device such as a transformer is filled with insulating oil for the purpose of electric insulation. Conventionally, insulating oil containing PCB (polychlorinated biphenyl) has been widely used for the purpose of improving characteristics such as electrical insulation. However, as is well known, PCBs have been pointed out to have environmental pollution and harm to the human body, and there are laws and regulations prohibiting the new manufacture and installation of electrical equipment that uses insulating oil containing PCBs. It was.

  And when renewing or discarding the electrical equipment filled with the PCB-containing insulating oil that has existed before the legal regulations, the PCB-containing insulating oil that has been filled is required to be rendered harmless. On the other hand, for electrical equipment that has been in use without being renewed or discarded at the moment, when conducting internal inspections or remodeling work, the insulating oil containing the filled PCB must be removed once and the inside of the safe tank. Sampling work for temporary storage is performed.

  For example, in order to extract insulation oil containing PCB filled in a transformer, connect a drain pipe to a drain pipe with an open / close valve provided near the bottom of the transformer, and connect the tip of the drain pipe to an oil tank. Communicate within. The drain pipe is equipped with a pump, filter and moisture remover, and the insulating oil filled in the transformer flows out to the drain pipe by opening the on-off valve and operating the pump, and insulated by the filter and moisture remover Remove dust and water contained in the oil and temporarily store it in the oil tank. After the internal inspection and remodeling work of the transformer is completed, the insulating oil temporarily stored in the oil tank is returned to the transformer.

  Insulating oil containing PCB adheres inside the exhaust pipe, pump, filter, moisture remover, and oil tank after the sampling work. However, in many cases, these devices are construction devices that are repeatedly used during sampling, and are transported to another construction site in a form separated from each other, for example. Therefore, it is necessary to reduce PCB, which is a harmful substance, to a regulated value (for example, 0.5 ppm or less), and the attached insulating oil must be removed by some means.

  Since the discharge pipe, pump, filter, moisture remover and the like have a relatively small internal volume, the attached insulating oil can be easily removed simply by circulating the cleaning liquid. However, the oil tank has a size of about 2m wide, 4m wide, and 2.5m high, and its internal volume is very large. Therefore, the cleaning liquid circulation system requires a large amount of cleaning liquid and is contaminated with harmful substances. This is not practical because a large amount of cleaning liquid is generated. Therefore, conventionally, the insulating oil containing PCB adhering to the inside of the oil tank is removed by a manual wiping operation.

  However, the manual wiping operation is a method in which an operator wearing protective clothing enters an oil tank and wipes it with a large amount of waste. The work efficiency is low and the safety is not perfect. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a new tank structure and a tank cleaning method for solving such problems in removing a liquid containing harmful substances adhering to a conventional tank. .

The tank structure of the present invention that solves the above problems includes a tank (1) comprising a side wall (2) surrounding the four circumferences, a top wall (3) and a bottom wall (4)
A plurality of lateral distribution pipes (8) provided in parallel near the pair of opposite side walls (2) and the top wall (3);
A plurality of vertical distribution pipes (9) that communicate with each of the horizontal distribution pipes (8) so as to extend downward, and are provided in parallel in proximity to the other pair of opposing side walls (2);
A plurality of contact distribution pipe (10) provided in parallel close to the side wall (2) which communicate with, and to the other pair opposite the horizontally between said horizontal distribution pipe (8),
Each of the distribution pipes (8), (9), and (10) is provided with a plurality of injection nozzles (12) capable of injecting the cleaning liquid at regular intervals on the side wall adjacent to them or the inner surface on the side closer to the top wall. And
One end of the horizontal distribution pipe (8) arranged at the upper part penetrates the side wall (2) in a liquid-tight manner and is led out of the tank (1) and connected to the cleaning liquid supply means (20). And a discharge part (13) penetrating liquid-tightly is provided on the side wall (2) of the tank bottom.

  Since the tank structure of the present invention is configured to wash harmful substances adhering to the inside of the tank with a cleaning liquid sprayed from a plurality of spray nozzles installed two-dimensionally, the tank itself has a cleaning function. Yes. And when cleaning using this tank structure, harmful substances attached to the side walls of the tank and the inner surface of the top wall can be efficiently cleaned with a small amount of cleaning liquid due to the spraying force (impact force) of the cleaning liquid, and further dropped after spraying When the cleaning liquid is discharged from the bottom of the tank to the outside, the inner surface of the bottom can be washed away intensively. Therefore, the inside of the tank can be cleaned with high efficiency without using a large amount of cleaning liquid as in the prior art, and the construction time and construction cost can be significantly reduced. In addition, the amount of cleaning liquid containing harmful substances is reduced.

Further, a plurality of horizontal distribution pipes 8 are provided in parallel near the pair of side walls 2 and the top wall 3 in the tank, and the vertical distribution pipe 9 is extended downward from each of the horizontal distribution pipes 8 to The side distribution pipes 8 are provided in parallel in the vicinity of the pair of side walls 2 and communicated by a plurality of connecting distribution pipes 10 in parallel in the vicinity of the other pair of opposing side walls 2. The pipes 8, 9, and 10 are provided with a large number of spray nozzles 12 that can spray the cleaning liquid at regular intervals on the inner wall on the side wall close to them or on the near side of the top wall. can do.
Moreover, each distribution pipe is provided all in close proximity to the side wall or top wall and, since having a large number of injection nozzles 12 at a constant interval can be washed each distributor pipe itself by the cleaning liquid reflected on the wall surface or the like.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view of a tank structure of the present invention and a diagram showing a cleaning liquid supply means for supplying a cleaning liquid thereto, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. is there. In these drawings, a tank 1 has side walls 2, a top wall 3, and a bottom (bottom wall) 4 that surround four circumferences made of a metal plate such as a steel plate, and an operator is placed on the top wall 3 and / or the side wall 2. An opening (not shown) with an open / close lid such as a manhole is provided. And the tank 1 is supported by the several support stand 6 temporarily installed on the foundation 5 of the oil extraction construction site.

Inside the tank 1, a cleaning liquid ejecting means 7 composed of a metal pipe such as a steel pipe is installed. The cleaning liquid ejecting means 7 is supported by welding or stretching between a pair of left and right side walls 2 in FIGS. 1 and 2, or a plurality of (in this example, nine) horizontal distribution pipes 8 and each horizontal pipe 8 A plurality (6 in this example) of vertical distribution pipes 9 communicating so as to extend vertically downward from the distribution pipe 8 and a plurality of (16 in this example) communicating horizontally between the horizontal distribution pipes 8. The communication distribution pipe 10 is configured. Each pipe is disposed close to the inner surface of the tank. As shown in FIG. 2, the end portion of the horizontal distribution pipe 8 arranged at the upper center communicates with the introduction portion 11 formed of a short pipe penetrating the side wall 2 in a liquid-tight manner. The on-off valve 11a is attached to.

  The cleaning liquid ejecting means 7 can be either manufactured in advance and arranged in the tank 1 or assembled in the tank 1. In the former case, the cleaning liquid injection means 7 manufactured integrally is arranged in the tank 1 in the middle of assembly, and both ends of each side pipe 8 are fixed to the side walls 2 by welding or the like and supported. In the latter case, a connecting part such as a screw type or a flange type is formed in the communicating part of each distribution pipe constituting the cleaning liquid ejecting means 7, and these parts drop into the tank 1 from the opening, The horizontal distribution pipe 8 is supported in the tank 1 and then the connecting portions are connected to each other.

  When the latter assembling method is adopted, a part of each side pipe 8 in the axial direction has a short tube structure that can be expanded and contracted, and the short pipe structure part is extended and locked in that state. The pipe 8 can be detachably supported in a form of stretching on the side wall. If the cleaning liquid ejecting means 7 is configured to be detachable from the tank 1 as described above, there is an advantage that a normal tank can be easily modified to the tank structure of the present invention.

  Each distribution pipe is provided with a large number of injection nozzles 12 protruding at predetermined intervals, and the high-pressure cleaning liquid supplied into the distribution pipes is supplied from each injection nozzle 12 to the inside of the tank 1 (the inner surface of the side wall 2 and the inner surface of the top wall 3). ) Can be injected towards. On the other hand, the side wall 2 having the same height as the bottom portion 4 of the tank 1 is provided with a discharge portion 13 formed of a short pipe penetrating liquid-tightly, and an opening / closing valve 13 a is attached to the distal end portion of the discharge portion 13.

  As shown in FIG. 1, the cleaning liquid supply means 20 is communicated with the cleaning liquid ejecting means 7. The cleaning liquid supply means 20 is for supplying a high pressure generator 21 for supplying a high pressure cleaning liquid to the cleaning liquid injection means 7, a recovery pump 22 for recovering the cleaning liquid from the tank 1, and supplying the recovered cleaning liquid and the replenished cleaning liquid to the high pressure generator 21. A buffer tank 23, a flexible tube 24 such as a hose communicating therewith, and an open / close valve 25 provided on each flexible tube 24. The high-pressure generator 21 can be constituted by, for example, a high-pressure pump, and the high-pressure pump is provided with a pressure adjusting means for adjusting the discharge pressure.

  Next, a method for cleaning a liquid containing harmful substances adhering to the inside of the tank 1 will be described. For example, when the liquid adhered to the inside of the tank 1 is an insulating oil containing PCB which is a harmful substance, as described above, the cleaning method of the present invention includes a liquid having affinity with the insulating oil, that is, the same quality PCB. Use no new insulating oil as cleaning liquid. (The following description explains the case where the PCB-containing insulating oil adhering to the inside of the tank 1 is washed.)

  Before describing the cleaning method, first, a process of attaching insulating oil containing PCB to the inside of the tank 1 will be described. As described above, the tank 1 temporarily stores insulating oil containing PCB filled in electrical equipment such as a transformer. An electrical device 30 shown in FIG. 1 is filled with an insulating oil 32 containing PCB inside a casing 31, and an opening / closing valve 34 is attached to the tip of a drain pipe 33 provided near the bottom of the casing 31.

  When extracting the insulating oil from the electrical device 30, a drain system is connected to the drain pipe 33. The discharge system includes a filter 36, a moisture remover 37, a flexible discharge pipe 35 provided with a reversible rotary discharge pump 38, and a bypass on-off valve 39. One end of the discharge pipe 35 is connected to the on-off valve 34, and the other end is connected to the on-off valve 13 a attached to the discharge unit 13 of the tank 1. (At that time, the flexible tube 24 is removed from the on-off valve 13a.)

  When the on-off valve 34 and the on-off valve 13 a are opened and the discharge pump 38 is operated, the insulating oil 32 filled in the electric device 30 is temporarily stored in the tank 1 through the discharge pipe 35. At that time, solid content such as dust contained in the insulating oil 32 is removed by the filter 36, and moisture is removed by the moisture remover 37. In addition, this tank 1 shall be temporarily installed on the site as a reusable construction oil tank.

  When the temporary accommodation is completed, the on-off valves 34 and 13a are closed, and the discharge pump 38 is stopped. When the internal inspection and repair work of the electric device 30 is completed, the on-off valve 34, the on-off valve 13a, and the on-off valve 39 are opened, and the insulating oil 32 temporarily stored in the tank 1 is rotated by reversely rotating the discharge pump. To recover. And after collection | recovery of the insulating oil 32 to the electric equipment 30, the on-off valve 34 and the on-off valve 13a are closed again.

  In order to clean the tank 1 to which the insulating oil 32 containing PCB is adhered by the temporary housing, fresh insulating oil is stored as a cleaning liquid in the buffer tank 23, and the on-off valves 11a, 13a, 25 are opened. When the high-pressure generator 21 is operated, the cleaning liquid in the buffer tank 23 is sucked in by the high-pressure generator 21 and supplied as high-pressure liquid to the horizontal distribution pipe 8 disposed in the upper center of the cleaning liquid ejecting means 7.

  The cleaning liquid supplied to the horizontal distribution pipe 8 is supplied to all distribution pipes through the vertical distribution pipe 9 and the connection distribution pipe 10 from there. The cleaning liquid for each distribution pipe is sprayed toward the inner surface of the side wall 2 of the tank 1 and the inner surface of the top wall 3 from the plurality of spray nozzles 12 provided on them, and the insulating oil adhering to these inner surfaces is separated by the spraying force of the cleaning liquid. It is mixed with the cleaning liquid and falls to the bottom 4. At this time, a part of the cleaning liquid reflected on the inner surface of the tank hits the outer periphery of the pipe and cleans the pipe itself. When the recovery pump 22 is started when the cleaning liquid dropped on the bottom 4 stays to some extent, the cleaning liquid staying on the bottom 4 flows toward the side wall 2 and is recovered from there through the discharge section 13 to the buffer tank 23. At that time, the inner surface of the bottom portion 4 is efficiently cleaned by a washing action by the flow of the cleaning liquid.

  The cleaning liquid collected in the buffer tank 23 is mixed with the cleaning liquid stored in the buffer tank 23, and circulates inside the tank 1 through the high pressure generator 21 as a new cleaning liquid. When the internal cleaning of the tank 1 is completed, the operation of the high pressure generator 21 is stopped and the supply of the cleaning liquid to the tank 1 is stopped. Next, when there is no cleaning liquid remaining in the bottom 4 of the tank 1, the recovery pump 22 is stopped, then the cleaning liquid supply means 20 is disconnected from the tank 1, and the on-off valve 11 a and the on-off valve 13 a are closed. As a result, the tank 1 and the cleaning liquid supply means 20 are separated.

  The tank structure of the present invention can be used as a tank for temporarily storing a liquid containing harmful substances such as PCB-containing insulating oil, and can be used for cleaning the liquid adhering to the inside. The cleaning method of the present invention can be used for cleaning the adhered liquid.

The front sectional view of the tank structure of the present invention and the figure which shows the washing | cleaning liquid supply means which supplies a washing | cleaning liquid to it. AA sectional drawing of FIG. BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tank 2 Side wall 3 Top wall 4 Bottom part 5 Foundation 6 Support stand 7 Cleaning liquid injection means 8 Horizontal distribution pipe 9 Vertical distribution pipe 10 Connection distribution pipe

DESCRIPTION OF SYMBOLS 11 Introduction part 11a On-off valve 12 Injection nozzle 13 Discharge part 13a On-off valve 20 Cleaning liquid supply means 21 High pressure generator 22 Recovery pump 23 Buffer tank 24 Flexible pipe 25 On-off valve 30 Electric equipment

31 Casing 32 Insulating oil 33 Drain pipe 34 Open / close valve 35 Discharge pipe 36 Filter 37 Water remover 38 Discharge pump 39 Open / close valve

Claims (1)

A tank (1) consisting of a side wall (2), a top wall (3) and a bottom wall (4) surrounding the four circumferences;
A plurality of lateral distribution pipes (8) provided in parallel near the pair of opposite side walls (2) and the top wall (3);
A plurality of vertical distribution pipes (9) that communicate with each of the horizontal distribution pipes (8) so as to extend downward, and are provided in parallel in proximity to the other pair of opposing side walls (2);
A plurality of contact distribution pipe (10) provided in parallel close to the side wall (2) which communicate with, and to the other pair opposite the horizontally between said horizontal distribution pipe (8),
Each of the distribution pipes (8), (9), and (10) is provided with a plurality of injection nozzles (12) capable of injecting the cleaning liquid at regular intervals on the side wall adjacent to them or the inner surface on the side closer to the top wall. And
One end of the horizontal distribution pipe (8) arranged at the upper part penetrates the side wall (2) in a liquid-tight manner and is led out of the tank (1) and connected to the cleaning liquid supply means (20). The tank structure is characterized in that a discharge part (13) penetrating liquid-tightly is provided in the side wall (2) of the tank bottom part.

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