JPH1038770A - Waste liquid sampling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform correct sampling of waste liquid while preventing outflow thereof by sustaining the suction height of waste liquid in a pumping tube at a constant level. SOLUTION: A negative pressure is brought in a sampling pot 33 by means of a pumping pressure regulator 36 disposed in the way of a pressure regulation pipe 34 coupling between the upper part of the sampling pot 33 and the upper part of a waste liquid storage tank 29. When waste liquid 25 is sucked into a pumping tube 32 passing through the sampling pot 33, an opening regulator 42 controls the opening of a pressure regulation valve 38 for feeding the pumping pressure regulator 36 with working compression air 35 such that the differential pressure between the inlet side of the pressure regulation pipe 34 to the pumping pressure regulator 36 and the bottom part of the waste liquid storage tank 29 will be kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a waste liquid sampling apparatus. More specifically, the present invention relates to a waste liquid sampling device that enables a correct sampling to be performed by keeping a suction height of a waste liquid in a pumping pipe constant, and prevents a waste liquid from going outside. Things.

[0002]

2. Description of the Related Art In a nuclear power plant or the like, a waste liquid sampling device is provided in a waste liquid storage tank in order to check the components of the generated radioactive waste liquid.

The waste liquid sampling apparatus is, for example, shown in FIG.
It is as shown in.

That is, a waste liquid supply port 2 for supplying a waste liquid 1 such as a radioactive waste liquid generated in a nuclear power plant or the like, and a gas 3 such as air stored in an upper portion are discharged to a gas processing device (not shown). A waste liquid storage tank 5 having a vent port 4 to be obtained is provided.

[0005] A pumping pipe 8 having a suction port 6 and a discharge port 7 at the bottom of the waste liquid storage tank 5 and circulated through the outside of the waste liquid storage tank 5 is provided. A sampling pot 9 is provided.

[0006] A pressure adjusting pipe 10 is connected between the upper part of the sampling pot 9 and the upper part of the waste liquid storage tank 5, and compressed air 11 is blown into the pressure adjusting pipe 10 so that the pressure in the sampling pot 9 is reduced. A pumping pressure adjusting device 12 such as an air jet device capable of adjusting the pressure is provided, and a pressure adjusting valve 14 is provided in the middle of an air pipe 13 for sending the compressed air 11 to the pumping pressure adjusting device 12. The opening of the pressure adjusting valve 14 is adjusted by an opening adjusting signal 16 from a pressure controller 15 configured to detect the pressure on the inlet side of the fluid pressure adjusting device 12, so that the inside of the sampling pot 9 has a constant negative pressure. So that it can be adjusted.

On the other hand, at a position near the suction port 6 of the pumping tube 8,
A pump 18 such as an air lift pump driven by the compressed air 17 to circulate the waste liquid 1 in the pumping pipe 8 is provided, and sampling is performed in the middle of an air pipe 19 for sending the compressed air 17 to the pump 18 such as an air lift pump. Valve 2
0 is provided.

In the figure, reference numeral 21 denotes a liquid level of the waste liquid storage tank 5;
Is the suction height in the pumping tube 8, and 23 is the sampling pot 9.
Sampling needle for sampling inserted into 2
Reference numeral 4 denotes a liquid level meter which detects the pressure at the bottom and the pressure at the top of the waste liquid storage tank 5 and measures the liquid level 21 from the pressure difference between the two.

The operation according to the above configuration is as follows.

That is, a waste liquid 1 such as a radioactive waste liquid generated in a nuclear power plant or the like is supplied into a waste liquid storage tank 5 through a waste liquid supply port 2.

The pressure of the pressure adjusting pipe 10 connected between the upper part of the sampling pot 9 and the upper part of the waste liquid storage tank 5 at the inlet side of the liquid pressure adjusting device 12 is detected by a pressure controller 15, 15 sends an opening adjustment signal 16 to the pressure controller 15 so that the inside of the sampling pot 9 of the pressure adjustment pipe 10 has a constant negative pressure, and the pressure controller 15 receives the opening adjustment signal 16 from the pressure controller 15. The opening degree is adjusted, and the compressed air 11 of the air pipe 13 is blown into the pressure adjusting pipe 10 from the liquid pressure adjusting apparatus 12 such as an air jet device. By the blowing of the compressed air 11, the inlet side of the liquid pressure adjusting device 12 of the pressure adjusting pipe 10 is sucked.

Then, the inside of the sampling pot 9 becomes negative pressure, so that the waste liquid 1 is sucked into the pumping pipe 8 according to the pressure difference between the pressure inside the sampling pot 9 and the pressure inside the waste liquid storage tank 5. That is, the liquid level of the waste liquid 1 becomes the suction height 22 according to the above-mentioned differential pressure.

When sampling the waste liquid 1, the sampling valve 20 is opened for a predetermined time.

Then, the compressed air 17 is sent to a pump 18 such as an air lift pump through an air pipe 19, and the pump 18 is driven for a certain period of time.
The waste liquid 1 is circulated inside.

As a result, the waste liquid 1 inside the sampling pot 9 provided in the middle of the pumping pipe 8 is replaced by the waste liquid 1 circulated through the pumping pipe 8, and the components of the waste liquid 1 inside the sampling pot 9 are stored in the waste liquid storage tank. 5 is equal to the component of the waste liquid 1.

In this manner, the waste liquid 1 in the sampling pot 9 is sampled by the sampling needle 23 when the component becomes equal to the component in the waste liquid storage tank 5.

[0017]

However, the above-mentioned conventional waste liquid sampling apparatus has the following problems.

That is, the liquid level 21 of the waste liquid 1 in the waste liquid storage tank 5 is controlled by controlling the pressure inside the sampling pot 9 to be a constant negative pressure by the liquid pressure adjusting device 12 such as an air jet device. If it changes, the suction height 22 of the waste liquid 1 in the pumping pipe 8 will change.

Then, when the pump 18 is driven for a certain period of time, the amount of circulation of the waste liquid 1 in the pumping pipe 8 changes. If the amount of circulation is small, the waste liquid 1 inside the sampling pot 9 can be sufficiently replaced. And sampling may not be performed correctly.

If the circulating amount of the waste liquid 1 in the pumping pipe 8 when the pump 18 is driven for a certain time is large, the waste liquid 1 in the sampling pot 9 flows into the pressure adjusting pipe 10 side,
There is a possibility that the mist is converted into a mist by the liquid pressure adjusting device 12 such as an air jet device and the liquid is discharged from the waste liquid storage tank 5 through the vent 4.

The present invention has been made in view of the above-mentioned circumstances, so that the suction height of the waste liquid in the pumping tube is kept constant, thereby enabling correct sampling and preventing the waste liquid from going outside. It is an object of the present invention to provide a waste liquid sampling device capable of performing the above.

[0022]

According to the present invention, a waste liquid storage tank 29 is provided.
A pumping pipe 32 having a suction port 30 and a discharge port 31 at the bottom thereof and extending upward and outside the waste liquid storage tank 29 in which the waste liquid 25 is circulated by a pump 44 is provided. A pressure adjusting pipe provided with a pumping pressure adjusting device capable of adjusting the pressure in the sampling pot by blowing compressed air between the upper portion of the sampling pot and the waste liquid storage tank. 34, and the compressed air 35
Differential pressure gauge provided with a pressure adjusting valve 38 in the middle of an air pipe 37 for sending pressure to detect the pressure difference between the pressure of the pressure adjusting pipe 34 at the inlet side of the liquid pressure adjusting device 36 and the pressure at the bottom of the waste liquid storage tank 29. 39, an opening adjustment signal 41 is sent to the pressure adjustment valve 38 based on the differential pressure signal 40 from the differential pressure gauge 39, and the opening of the pressure adjustment valve 38 is adjusted so that the differential pressure becomes constant. The present invention relates to a waste liquid sampling device, which is provided with an opening degree controller 42 to be controlled.

According to the above means, the following effects can be obtained.

The differential pressure between the pressure at the inlet side of the liquid pressure adjusting device 36 of the pressure adjusting tube 34 connected between the upper part of the sampling pot 33 and the upper part of the waste liquid storage tank 29 and the pressure at the bottom of the waste liquid storage tank 29 is measured. 39, based on a differential pressure signal 40 from the differential pressure gauge 39, the opening degree controller 42 sends an opening degree adjusting signal 41 to the pressure adjusting valve 38 so that the differential pressure becomes constant. The compressed air 35 of the air pipe 37 is blown into the pressure adjusting pipe 34 from the liquid pressure adjusting device 36. By the blowing of the compressed air 35, the inlet side of the liquid pressure adjusting device 36 of the pressure adjusting pipe 34 is sucked.

Then, since the inside of the sampling pot 33 becomes negative pressure, the pumping pipe 32 is set in accordance with the pressure difference between the pressure inside the sampling pot 33 and the pressure inside the waste liquid storage tank 29.
The waste liquid 25 is sucked into the inside, and the liquid level of the waste liquid 25 becomes the suction height 48 according to the above-mentioned differential pressure.

Further, in the present invention, since the above-mentioned differential pressure is controlled to be constant, the suction height 48 of the waste liquid 25 in the pumping pipe 32 changes with the change of the liquid level 47 in the waste liquid storage tank 29. Regardless, it will always be kept constant.

When sampling the waste liquid 25, the pump 44 is driven for a certain period of time, and the pump 44 circulates the waste liquid 25 in the pumping pipe 32.

As a result, the waste liquid 25 inside the sampling pot 33 provided in the middle of the pumping pipe 32 is replaced by the waste liquid 25 circulated through the pumping pipe 32, and the components of the waste liquid 25 inside the sampling pot 33 are stored in the waste liquid storage tank. It becomes equal to the component of the waste liquid 25 in 29.

In this way, when the components in the waste liquid storage tank 29 become equal to each other, the waste liquid 2 in the sampling pot 33 is removed.
5 is to be sampled.

As described above, according to the present invention, the pressure difference between the pressure inside the sampling pot 33 and the pressure inside the waste liquid storage tank 29 is controlled by the liquid pressure adjusting device 36 so as to be always constant. Liquid level 4 of waste liquid 25 in storage tank 29
7, the suction height 48 of the waste liquid 25 in the pumping pipe 32
Will not change.

As a result, the circulating amount of the waste liquid 25 in the liquid pumping pipe 32 when the pump 44 is driven for a certain time is kept constant, and the waste liquid 25 in the sampling pot 33 cannot be sufficiently replaced. Is prevented from being performed.

Further, the circulation amount of the waste liquid 25 in the liquid pumping pipe 32 when the pump 44 is driven for a certain period of time does not become too large.
5 flows into the pressure adjusting pipe 34 side, is converted into mist by the pumping pressure adjusting device 36 such as an air jet device, and is prevented from flowing out of the waste liquid storage tank 29 through the vent port 28.

[0033]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

A waste liquid supply port 26 for supplying a waste liquid 25 such as a radioactive waste liquid generated in a nuclear power plant or the like, and a gas 27 such as air stored in an upper portion thereof can be discharged to a gas processing device (not shown). A waste liquid storage tank 29 having a bent port 28 is provided.

A pumping tube 32 having a suction port 30 and a discharge port 31 at the bottom of the waste liquid storage tank 29 and circulating through the outside of the waste liquid storage tank 29 is provided. A sampling pot 33 is provided.

Then, a pressure adjusting pipe 34 is connected between the upper part of the sampling pot 33 and the upper part of the waste liquid storage tank 29,
A pumping pressure adjusting device 36 such as an air jet device capable of adjusting the pressure in the sampling pot 33 by blowing compressed air 35 is provided in the pressure adjusting pipe 34.

A pressure regulating valve 38 is provided in the middle of an air pipe 37 for sending compressed air 35 to the liquid pressure adjusting device 36, and the pressure of the pressure adjusting tube 34 on the side of the liquid pressure adjusting device 36 and the waste liquid storage tank 29 are provided. Differential pressure gauge 3 for detecting the differential pressure from the pressure at the bottom
9, an opening degree adjustment signal 41 is sent to the pressure adjustment valve 38 based on the differential pressure signal 40 from the differential pressure gauge 39, and the pressure adjustment valve 3
An opening controller 42 is provided for controlling the opening of the opening 8 so that the differential pressure is constant.

On the other hand, a pump 44 such as an air lift pump driven by the compressed air 43 to circulate the waste liquid 25 in the pumping pipe 32 is provided at a position near the suction port 30 of the pumping pipe 32. Pumps 4 such as pumps
A sampling valve 46 is provided in the middle of an air pipe 45 for sending the compressed air 43 to 4.

In the figure, reference numeral 47 denotes the liquid level of the waste liquid storage tank 29;
8 is a suction height in the pumping tube 32, 49 is a sampling needle inserted into the sampling pot 33 for sampling, 50 is a pressure detecting device for detecting the pressure at the bottom and the pressure at the top of the waste liquid storage tank 29, and This is a liquid level meter that measures the liquid level 47.

Although the pressure at the bottom of the waste liquid storage tank 29 by the differential pressure gauge 39 is measured by using the liquid level gauge 50, the pressure may be separately measured.

Next, the operation will be described.

A waste liquid 25 such as a radioactive waste liquid generated in a nuclear power plant or the like is supplied into a waste liquid storage tank 29 through a waste liquid supply port 26.

Then, a pressure adjusting pipe 34 connected between the upper part of the sampling pot 33 and the upper part of the waste liquid storage tank 29.
The differential pressure gauge 39 detects the differential pressure between the pressure at the inlet side of the pumping pressure adjusting device 36 and the pressure at the bottom of the waste liquid storage tank 29, and based on the differential pressure signal 40 from the differential pressure gauge 39, The opening degree adjustment signal 41 is sent to the adjustment valve 38 so that the differential pressure is constant, the opening degree of the pressure adjustment valve 38 is adjusted, and the compressed air 35 of the air pipe 37 is adjusted to the pumping pressure of an air jet device or the like. The air is blown from the device 36 into the pressure adjusting tube 34. By the blowing of the compressed air 35, the inlet side of the liquid pressure adjusting device 36 of the pressure adjusting pipe 34 is sucked.

Then, the pressure inside the sampling pot 33 becomes negative, so that the pumping pipe 32 is operated in accordance with the pressure difference between the pressure inside the sampling pot 33 and the pressure inside the waste liquid storage tank 29.
The waste liquid 25 is sucked into the inside, and the liquid level of the waste liquid 25 becomes the suction height 48 according to the above-mentioned differential pressure.

In addition, in the present invention, since the above-mentioned differential pressure is controlled to be constant, the suction height 48 of the waste liquid 25 in the pumping pipe 32 changes according to the change of the liquid level 47 in the waste liquid storage tank 29. Regardless, it will always be kept constant.

When sampling the waste liquid 25, the sampling valve 46 is opened for a predetermined time.

Then, the compressed air 43 is sent to a pump 44 such as an air lift pump via an air pipe 45, and the pump 44 is driven for a certain period of time.
A waste liquid 25 is circulated through the inside of the tank.

As a result, the waste liquid 25 inside the sampling pot 33 provided in the middle of the pumping pipe 32 is replaced by the waste liquid 25 circulated through the pumping pipe 32, and the components of the waste liquid 25 inside the sampling pot 33 are stored in the waste liquid storage tank. It becomes equal to the component of the waste liquid 25 in 29.

When the components in the waste liquid storage tank 29 become equal to the components in the waste liquid storage tank 29, the waste liquid
5 is sampled by the sampling needle 49.

As described above, according to the present invention, the pressure difference between the pressure inside the sampling pot 33 and the pressure inside the waste liquid storage tank 29 is controlled by the pumping pressure adjusting device 36 such as an air jet device so as to be always constant. Waste tank 2
Even if the liquid level 47 of the waste liquid 25 in the pipe 9 changes, the suction height 48 of the waste liquid 25 in the pumping pipe 32 does not change.

As a result, the circulating amount of the waste liquid 25 in the liquid pumping pipe 32 when the pump 44 is driven for a predetermined time is kept constant, and the waste liquid 25 in the sampling pot 33 cannot be sufficiently replaced. Is prevented from being performed.

Further, the circulation amount of the waste liquid 25 in the liquid pumping pipe 32 when the pump 44 is driven for a certain period of time is not excessively increased.
5 flows into the pressure adjusting pipe 34 side, is converted into mist by the pumping pressure adjusting device 36 such as an air jet device, and is prevented from flowing out of the waste liquid storage tank 29 through the vent port 28.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0055]

As described above, according to the waste liquid sampling apparatus of the present invention, it is possible to perform a correct sampling while keeping the suction height of the waste liquid in the liquid pumping pipe constant, and to reduce the waste liquid. An excellent effect that it can be prevented from going outside can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of an example of an embodiment of the present invention.

FIG. 2 is a schematic system diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 25 waste liquid 29 waste liquid storage tank 30 suction port 31 discharge port 32 pumping pipe 33 sampling pot 34 pressure control pipe 35 compressed air 36 pumping pressure control device 37 air pipe 38 pressure control valve 39 differential pressure gauge 40 differential pressure signal 41 opening degree control signal 42 Opening controller 44 Pump

Claims (1)

[Claims] An inlet (3) is provided at the bottom of a waste liquid storage tank (29).
0) and a discharge port (31), and a waste liquid storage tank (29) in which the waste liquid (25) is circulated by a pump (44).
And a pumping pipe (32) extending upward and outside of the pump.
A sampling pot (33) is provided at the uppermost position of 2),
Upper part of sampling pot (33) and waste liquid storage tank (29)
A pressure adjusting pipe (34) provided with a pumping pressure adjusting device (36) capable of adjusting the pressure in the sampling pot (33) by blowing compressed air (35), A pressure adjusting valve (38) is provided in the middle of an air pipe (37) for sending compressed air (35) to the pumping pressure adjusting device (36), and the pressure adjusting pipe (34) is inserted into the pumping pressure adjusting device (36). Pressure gauge (39) for detecting the pressure difference between the pressure on the side and the pressure at the bottom of the waste liquid storage tank (29), and a pressure regulating valve (40) based on the pressure difference signal (40) from the pressure difference gauge (39). An opening controller (42) for sending an opening adjustment signal (41) to the pressure adjusting valve (38) to adjust the opening of the pressure adjusting valve (38) so that the differential pressure is constant. Characteristic waste fluid sampling device.