JP3962407B2 - Liquid storage tank leak inspection device - Google Patents

Description

  The present invention relates to a leak inspection apparatus for inspecting the presence or absence of liquid leakage from a liquid storage tank installed in a gas station, a factory, or the like. In addition, in this application, "leakage" shall mean both the outflow of the storage liquid from a liquid storage tank, and the inflow of rain water, groundwater, etc. to a liquid storage tank.

  Since liquid storage tanks buried underground are used for a long time, holes or cracks occur due to corrosion of the partition wall, or the liquid stored inside flows out to the outside for other reasons, or Rainwater, groundwater, etc. may flow from the outside.

  Conventionally, an apparatus described in Patent Document 1 is known as an apparatus for inspecting the presence or absence of such leakage. In the leakage inspection apparatus described in Patent Document 1, a float that floats on a liquid surface and a swing balancer that can swing around a pivot are connected by a wire, and an indicator needle is provided on the pivot. That is, in the leak inspection apparatus described in Patent Document 1, when the float moves up and down due to liquid leakage, the pivot supporting the swing balancer rotates, and the indicator needle swings accordingly. Is recorded on the recording board and monitored to check for leaks.

  However, in the leakage inspection apparatus described in Patent Document 1, when the float moves up and down (liquid level fluctuation) due to liquid leakage is minute, the indicator needle also swings so that it is difficult to inspect for leakage. There was a problem. That is, as a measure of the presence or absence of leakage according to the US standard, it is determined that there is leakage when the change in liquid volume is 0.38 L / h or more, but when this is converted into fluctuation in the liquid level, for example, a tank of 10 kL In such a case, it is as small as about 0.05 mm, and it is difficult for the leak inspection apparatus described in Patent Document 1 to detect such a minute fluctuation in the liquid level.

  On the other hand, the applicant of the present application previously proposed a leak inspection apparatus in Japanese Patent Application No. 2004-67825 that improved the leak inspection apparatus described in Patent Document 1 and made it possible to detect minute fluctuations in the liquid level. . In this leakage inspection device, the length of the indicator needle is made longer than the length between the pivot fixing point and the wire fixing point in the swing balancer, thereby amplifying the vertical movement of the float and swinging the indicator needle. This is detected as a movement, and this is recorded on the rotary recording board at the notation portion at the tip of the indicator needle.

  However, these conventional leakage inspection apparatuses have the following problems.

  First, in a periodic inspection for inspecting the presence or absence of leakage in the liquid storage tank, in order to shorten the inspection time, the gas phase part and the liquid phase part are inspected simultaneously by applying pressure (positive pressure or negative pressure) to the gas phase part. Although none of the above-described leakage inspection devices have an airtight structure, pressure cannot be applied to the gas phase portion when a leakage inspection device that performs a leakage inspection of the liquid phase portion is attached. Therefore, the inspection of the gas phase portion and the liquid phase portion has to be performed separately, and there is a problem that the inspection time becomes long.

  Further, when a pressure (positive pressure or negative pressure) is applied to the gas phase portion for inspection of the gas phase portion, the internal pressure of the liquid storage tank changes, and as a result, the liquid in the liquid storage tank and the liquid storage tank itself are Since it expands or contracts, the zero point of the leakage inspection apparatus adjusted in the atmospheric pressure state (no pressure state) is shifted. Therefore, for the zero point readjustment, it is necessary to perform the troublesome work of measuring the zero point deviation amount under pressure and then returning to the atmospheric pressure state and adjusting for the zero point deviation amount. Met.

Further, in the leak inspection apparatus of Japanese Patent Application No. 2004-67825, the swinging movement of the pointing needle is amplified, but the force for swinging the pointing needle is small. There was also a problem that accurate measurement could not be performed because the swing of the indicator needle was smaller than the actual due to frictional resistance with the rotary recording disk.
No. 2-33238

The problem to be solved by the present invention is that a liquid storage tank capable of simultaneously performing a leak inspection of a gas phase portion and a liquid phase portion of a liquid storage tank and easily performing zero point adjustment from the outside . It is to provide a leakage inspection apparatus.

  Another object is to provide a liquid storage tank leakage inspection device capable of reliably recording minute fluctuations in the liquid level.

The present invention includes a float that floats on a liquid surface, a wire that supports a float at a lower end, a midway fixed to a pivot, and a swingable arrangement around the axis of the pivot, and one end of the wire In a liquid storage tank leakage inspection apparatus, comprising: a swing balancer that is fixed and has a weight attached to the other end; and an indicator needle that has one end attached to the pivot and swings in conjunction with the pivoting of the pivot. A portion that communicates with the valve has an airtight structure, a zero point adjustment mechanism that moves the pivot up and down is provided to be operable from the outside, and the tip of the indicator needle is visible from the outside .

In the present invention, the rotary recording plate for recording the locus of contact with indicating section notation portion attached to the tip of the indicator needle can Rukoto provided intermittently cutout hole along the direction of rotation.

  Further, in the present invention, the length of the indicator needle is preferably longer than the length between the pivot fixing point and the wire fixing point in the swing balancer, and more preferably the indicator needle length is the swing balancer. The length between the fixed point of the pivot and the fixed point of the wire is 5 times or more.

  In the present invention, since the portion communicating with the liquid storage tank has an airtight structure, it is possible to apply pressure to the gas phase portion of the liquid storage tank with the leakage inspection device attached. Can be performed at the same time, and the inspection time can be shortened.

Further, according to the present invention, the notation portion is positioned in the cutout hole by intermittently providing cutout holes along the rotation direction on the rotary recording disk that records the locus of the notation portion attached to the indicator needle. When it is, there is no friction with the rotary recording disk. Thus, even variations in the liquid level fine reliably swing indicator needle, Ru can be reliably recorded in the portion other than the cutout hole of the rotary recording plate by indicating section that locus.

Furthermore, by providing an adjustment mechanism for moving the pivot of the swing balancer from the outside, the zero point adjustment can be easily performed from the outside, and the working time for the zero point adjustment can be shortened. In addition, the zero point adjustment can be performed more easily and accurately by making the tip of the indicating needle, the notation portion, and the rotary recording board inside the apparatus visible from the outside.

  In addition, by making the length of the indicator needle longer than the length between the pivot fixed point and the wire fixed point in the swing balancer, the vertical movement of the float is amplified and appears as the swing of the indicator needle. Therefore, it is possible to detect minute fluctuations in the liquid level due to the leakage of the liquid, and it is possible to perform a highly accurate leakage inspection.

  Hereinafter, embodiments of the present invention will be described by way of examples in which the present invention is applied as a leak inspection device for an underground tank of a gas station.

  FIG. 1 is a schematic configuration diagram of a gas station to which a leakage inspection apparatus of the present invention is applied. An underground tank A is embedded in the gas station, and a manhole B is provided above it. A main body case 1 of the leakage inspection apparatus C is installed above the manhole B, and the main body case 1 and the underground tank A are connected by a communication pipe D.

  FIG. 2 is a front view showing a main part of the leakage inspection apparatus C, and FIG. 3 is a side view thereof.

  The main body case 1 of the leakage inspection apparatus C includes a storage portion 1a and a lid portion 1b, and has an airtight structure by tightening the lid portion 1b to the storage portion 1a with a tightening bolt via a packing 1c. As a result, pressure (positive pressure or negative pressure) can be applied to the gas phase portion of the underground tank A with the leak inspection device C attached, and the liquid phase portion and the gas phase portion can be inspected at the same time. It has become. In the present embodiment, the lid 1b is formed of a transparent or translucent member such as an acrylic plate so that the inside of the main body case 1 can be seen.

  A pivot support member 2 is disposed in the main body case 1, and a pivot 3 is rotatably supported by the pivot support member 2. An adjustment screw 4 is screwed onto the pivot support member 2 as an adjustment mechanism for moving the pivot 3. The adjustment screw 4 is attached to the main body case 1 via an airtight seal material 5 and can be operated from outside the main body case 1. The lower portion of the adjustment screw 4 is supported by a support portion 6 fixed to the main body case 1 so as not to move up and down, and the pivot support member 2 is attached around the adjustment screw 4 so as not to rotate. By rotating the screw 4, the pivot support member 2 moves up and down, and the pivot 3 also moves up and down.

  The middle of the swing balancer 7 is fixed to the pivot 3. A midway of a wire 9 for hanging the float 8 is fixed to one end of the swing balancer 7 by a fixing mechanism 10, and a weight 11 is attached to the other end. A float 8 that floats on the liquid level in the underground tank A is connected to the lower end of the wire 9. When the float 8 is floating, the swing balancer 7 keeps an equilibrium state. The relationship between the buoyancy and the gravity of the weight 11 is adjusted. The upper end of the wire 9 is wound around the rotary roll 12.

  One end (base end) of an indicator needle 13 is fixed to the pivot 3, and a notation portion 14 made of a pen or the like is attached to the tip of the indicator needle 13. The notation unit 14 abuts on the rotary recording board 15 rotated by a mechanical mechanism such as a spring that does not use electricity, and records the locus on the rotary recording board 15.

  As shown in FIG. 2, the rotary recording board 15 has cutout holes 15a intermittently provided at equal intervals along the rotation direction, and is indicated by the other parts (between the cutout holes 15a). The locus of the part 14 is recorded. In this embodiment, the rotary recording board 15 is rotated so as to rotate once in one hour, and the locus of the notation unit 14 is recorded at a frequency of once every five minutes.

  Here, the length L1 of the indicating needle 13 is longer than the length L2 between the fixing point of the pivot 3 and the fixing point (fixing mechanism 10) of the wire 9 in the swing balancer 7.

  FIG. 4 is a cross-sectional view showing a fixing mechanism 10 that fixes a wire to the swing balancer 7.

  In this fixing mechanism 10, the swing balancer 7 is composed of two wall plates 7a and 7b that hold the swing balancer 7 at a constant interval, and is sandwiched between a cylindrical body 10a and an insertable insertion body 10b in the cylindrical body 10a. A mechanism is provided. The cylindrical body 10a and the insertion body 10b are urged away from each other by a spring 10c. Wire insertion holes 10d and 10d 'are provided in the overlapping portions, and the wire 9 is inserted into these wire insertion holes 10d and 10d'. . Since the cylindrical body 10a and the insertion body 10b are urged away from each other, the wire insertion holes 10d and 10d 'are urged in alternate directions, and the wire 9 is fixed.

  When such a fixing mechanism 10 is adopted, the fixing of the wire 9 and the swing balancer 7 is quickly released by pressing both end surfaces of the cylinder 10a and the insert 10b, and the initial liquid level in the underground tank A The wire 9 can be easily moved up and down according to the level.

  Next, the operation of the leakage inspection apparatus C will be described.

  When there is no change in the liquid level in the underground tank A, the balance of the swing balancer 7 is maintained as described above, and the indicator needle 13 does not swing. Record the same circular trajectory on 15.

  When the liquid level in the underground tank A moves up and down due to leakage, the swing balancer 7 swings by the up and down movement of the float 8 and the pivot 3 rotates. The indicator needle 13 swings in conjunction with the rotation of the pivot 3, and a different locus is recorded on the rotary recording board 15 by the notation unit 14. As a result, leakage can be detected.

  At this time, in this embodiment, since the rotary recording board 15 is provided with the cutout holes 15a intermittently along the rotation direction, the rotary recording board is located when the notation portion 14 is located in the cutout hole 15a. No friction with 15 occurs. Therefore, even if the fluctuation of the liquid level is very small, the indicator needle 14 is reliably swung, and the locus thereof can be reliably recorded by the notation portion 15 in a portion other than the cutout hole 15a of the rotary recording board 15. Instead of providing a cut-out hole in the rotary recording board 15, the surface of the rotary recording board 15 is treated with, for example, a low-friction coating material so that the coefficient of friction is low enough to allow the notation 14 to slide freely. Produces the same effect.

  In the present embodiment, the length L1 of the indicating needle 13 is longer than the length L2 between the pivot 3 fixing point and the wire 9 fixing point (fixing mechanism 10) in the swing balancer 7. 13 The amplitude of the swing of the tip is amplified by the vertical movement of the wire 9 fixing point (fixing mechanism 10) of the swing balancer 7 caused by the vertical movement of the float 8. Therefore, a minute change in the liquid level due to a liquid leakage of about 0.38 L / h can also be detected. In the embodiment, L1 is longer than L2, but in order to reliably detect liquid leakage of about 0.38 L / h, it is preferable to set L1 to 5 times or more than L2.

  Next, a zero point adjustment method of the leakage inspection apparatus C will be described.

  The zero point adjustment of the leakage inspection apparatus C is performed by operating the adjustment screw 4 and moving the pivot support member 2 and the pivot 3 up and down as described above. When the pivot 3 moves up and down, one end side of the swing balancer 7 is fixed to the wire 9, so that the swing balancer 7 tilts around the pivot 9 and the pivot 3 rotates. The indicator needle 13 swings in conjunction with the rotation of the pivot 3. In this way, by operating the adjustment screw 4 from the outside to move the pivot 3 up and down, the swinging amount of the indicating needle 13 is adjusted to adjust the zero point.

  Here, as described above, the lid portion 1b of the main body case 1 is formed of a transparent or translucent member so that the inside of the main body case 1 can be visually checked. The adjustment can be performed while visually confirming the section 14 and the rotary recording board 15, and the zero point adjustment operation can be performed easily and accurately.

  In the embodiment, the entire lid portion 1b is formed of a transparent or translucent member. However, a part of the lid portion 1b is formed of a transparent or translucent member so that at least the notation portion 14 and the rotary recording board 15 are external. It can also be made visible.

  The present invention can be applied as a leakage inspection apparatus that inspects leakage of liquid from any liquid storage tank installed in a gas station, a factory, or the like.

It is a schematic block diagram of the gas station to which the leakage inspection apparatus of this invention is applied. It is a front view which shows the principal part of the leakage inspection apparatus of this invention. It is a side view which shows the principal part of the leakage inspection apparatus of this invention. It is sectional drawing which shows the fixing mechanism which fixes a wire to a swing balancer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body case 1a Storage part 1b Cover part 1c Packing 1d Tightening bolt 2 Pivot support member 3 Pivot 4 Adjustment screw 5 Airtight seal material 6 Support part 7 Swing balancer 7a, 7b Wall board 8 Float 9 Wire 10 Fixing mechanism 10a Cylindrical body 10b Insertion Body 10c Spring 10d, 10d 'Wire insertion hole 11 Weight 12 Rotating roll 13 Pointer 14 Marking part 15 Rotating recording board 15a Cutout hole A Underground tank B Manhole C Leakage inspection device D Communication pipe

Claims (4)

A float floating on the liquid surface;
A wire for hanging a float at the lower end;
A swing balancer that is fixed midway to the pivot and is arranged so as to be swingable around the axis of the pivot, and having one end fixed to the wire and a weight attached to the other end,
In the liquid storage tank leakage inspection apparatus having one end attached to the pivot and an indicator needle that swings in conjunction with the pivot of the pivot,
The part communicating with the liquid storage tank has an airtight structure ,
A zero point adjustment mechanism that moves the pivot up and down is provided so that it can be operated from the outside.
A liquid storage tank leakage inspection device characterized in that the tip of the indicator needle is visible from the outside . Further comprising a signage unit attached to the tip of the finger示針, a rotary recording plate for recording the trajectory of the indicating section abuts the indicating section,
The liquid storage tank leakage inspection device according to claim 1, wherein the rotary recording disk is provided with cutout holes intermittently along a rotation direction thereof. 3. The liquid storage tank leakage inspection device according to claim 1, wherein a length of the indicator needle is longer than a length between a pivot fixing point and a wire fixing point in the swing balancer . 4. The liquid storage tank leakage inspection device according to claim 3, wherein a length of the indicator needle is five times or more a length between a pivot fixing point and a wire fixing point in the swing balancer .

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