JPS58215520A - Leakage detector for lined vessel - Google Patents

Abstract

PURPOSE:To detect speedily leakage from a lined vessel and to prevent a leakage signal from outputting due to dewing, by providing a leakage detector which outputs the leakage signal by the contact of fluid and a dry air supplying device which supplies dry air where the leakage detector is installed. CONSTITUTION:Leaking water spreads between a lining plate 4 and a concrete body 2 and sticks immediately to the leakage detector 9 at a cracking installation part, and consequently the leakage detector 9 varies in resonance impedance greatly. A leakage monitoring device 12 detects the variation in resonance impedance of the leakage detector 9 through a connection line 11 to output a warning signal to, for example, a warning device. Then, an opening and closing valve 17 inserted into a vent pipe 14 is opened and a pressure reducing valve 16 is regulated to supply irreducible dry air which never causes dewing from a cylinder 15 to a conduit groove 5 arranged at the leakage detector 9 and a recessed part 8 formed in the concrete body 2 at all times, so no water due to dewing sticks to the leakage detector 9.

Description

[Detailed description of the invention] [Technical field of the invention] The present invention relates to a leak detection device for a lining tank.

[Technical Background of the Invention] Lined tanks with a metal lining made of, for example, stainless steel have been widely used in nuclear power-related facilities, general chemical plants, and the like.

For example, in nuclear power-related facilities, lined tanks are used to temporarily store radioactive waste water and guide it to the next process, the water purification system. Since it will be stored, careful consideration has been taken to prevent leakage.

In the unlikely event that a leak occurs, a leak detection device for the lining tank is provided to detect it.

In general, a lining tank is composed of a concrete frame, embedded hardware embedded in the concrete frame, and a lining plate that is welded to the concrete frame and lined with the embedded metal using the embedded metal as a backing. A water guide groove is formed in the embedded metal fitting, and a water guide pipe connected to the drain pot is connected to this water guide groove.

In a lining tank configured in this way, if a crack occurs in the lining plate for some reason and leakage occurs, the leaked water is collected in the water guide groove, passes through the water guide pipe, reaches the drain pot, and is placed in the drain pot. The leak detection device detects the occurrence of a leak.

[Problems with back garden technology] However, when detecting leaks using this method, there is generally a small gap between the lining board and the concrete body 1-11, and it is difficult for water to leak into this gap. As the water remains, the amount of leaked water that reaches the water channel is reduced by half, and since it takes a long time to travel from the water channel to the water pipe and reach the drain pot, the detection of the leak is delayed, and the leak must be left untreated during this time. There is a problem. In addition, generally the water stored in the lining tank is hot water, and since the lining plate that discharges this hot water cools down first, condensation occurs on the concrete frame side of the lining plate, and it takes time for the condensed water to reach the drain pot, causing the water to be stored. There was a problem in that it was not possible to distinguish between the leakage that occurred during the discharge and the condensation that occurred after the discharge.

[Object of the invention] The present invention has been made in response to such conventional circumstances,
It is an object of the present invention to provide a leakage detection device for a lining tank that can quickly detect leakage from the lining tank and that does not output a leakage signal due to dew condensation.

[Summary of the Invention] That is, the present invention provides a leak detector that is disposed between a concrete frame and a lining plate lined within the concrete frame and outputs a leak signal upon contact with a liquid, and a leak detector installation part. This is a leakage detection device for a lining tank, characterized by comprising a dry gas supply device for supplying dry gas to the lining tank.

[Embodiment of the Invention] The details of the present invention will be described below with reference to an embodiment shown in the drawings.

In FIG. 1, reference numeral 1 indicates a lining tank, and this lining tank 1 is made up of a concrete body 2, an embedded metal fitting 3 buried in the concrete frame 2, and a welded metal fitting 3 using the embedded metal fitting 3 as a backing. , and a lining plate 4 lined within a concrete frame 2.

As shown in FIG. 2, a water guide groove 5 is formed along the inner circumference of the embedded metal fitting 3, and this water guide groove 5 is connected to the lower part of the lining tank 1 by a water guide pipe 6 buried in the concrete frame 2. It is connected to the drain pot 7 provided therein. A large number of leak detectors 9 made of, for example, piezoelectric vibrators are disposed in the water guide groove 5 or in the recess 8 formed directly on the inner circumferential surface of the concrete frame 2. It is electrically connected to a leakage monitoring device 12 by a connecting wire 11 inserted into a conduit 10 buried in the leakage monitoring device 12 .

A vent pipe 14 of a dry gas supply device 13 for supplying dry gas such as dry nitrogen or dry air to the leak detector 9 is arranged in the leak groove 5 in which the leak detector 9 is arranged. The other end of the vent pipe 14 is connected to a cylinder 15 for storing dry gas, and a pressure reducing valve 16 and an on-off valve 17 are inserted into the vent pipe 14.

In the leak detection device for a lining tank configured as described above, a crack occurs in the lining plate 4, and leakage starts when the water level rises to the level of this crack, and the leaked water flows between the lining plate 4 and the concrete. It spreads between the building frame 2 and immediately adheres to the leak detector 9 located at the crack installation part,
As a result, the resonance symbiedance of the leakage detector 9 changes significantly. The leak monitoring device 12 detects a change in the resonant impedance of the leak detector 9 via the connection line 11, and outputs an alarm signal to, for example, an alarm device. This alarm allows a leak to be detected quickly, and the water stored in the lining tank 1 to be discharged quickly. Note that the leaked water is guided from the water guide groove 5 to the drain pot 7 through the water guide pipe 6.

In the leak detection device for a lining tank configured as described above, the on-off valve 17 inserted in the ventilation pipe 14 is opened, and the pressure reducing valve 16 is adjusted so that the water guide groove 5 in which the leak detector 9 is disposed and the concrete frame are opened. Since the minimum amount of dry gas is always supplied to the recess 8 formed in the cylinder 15 to prevent condensation from forming in the cylinder 15, water due to condensation does not adhere to the leak detector 9, and water due to condensation does not adhere to the leak detector 9. The generation of leakage signals is completely prevented.

[Advantageous Effects of the Invention 1] As described above, according to the lining tank leakage detection device of the present invention, leakage water can be detected quickly and reliably, and the water stored in the lining tank can be drained while the leakage is minimal. It is possible to prevent the surface of the concrete structure from being contaminated by leaked water, and to prevent leaked water from penetrating into the concrete structure. Further, leakage signals are no longer generated due to dew condensation, and situations such as plant shutdown due to misidentification can be completely prevented.

Furthermore, by arranging a large number of easy-to-install leak detectors made of piezoelectric vibrators, for example, the leak location can be limited to a narrow range, and the leak location can be easily found for repair.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing a leakage detection device for a lining tank according to an embodiment of the present invention, and FIG. 2 is an enlarged vertical sectional view showing the embedded metal installation part of FIG. 1. 2・・・・・・・・・・・・Concrete frame・4・・
・・・・・・・・・Lining plate 9・・・・・・・・・
...Leak detector 13... Dry gas supply device Patent attorney Satoshi Suyama - Figure 1, Figure z

Claims (1)

[Claims] (1) A leak detector that is installed between the concrete frame and the lining plate that lines the concrete frame and outputs a leak signal upon contact with liquid, and a dryer that supplies dry gas to the leak detector installation area. A leak detection device for a lining tank, comprising a gas supply device. (2) The leak detection device for a lining tank according to claim 1, wherein the leak detector is a piezoelectric vibrator.