JPH04102599A - Liquid transferring device - Google Patents

Abstract

PURPOSE:To greatly reduce troublesomeness in maintenance and supervising by placing a suction tank in a position higher than that of a receiving tank, and by providing a depressurizing device which depressurizes the inside of the suction tank for sucking of liquid in a liquid storage tank up to the suction tank. CONSTITUTION:With a vacuum pump 5 started with a three-way valve 11 driven and a depressurizing pipe 10 communicated with the vacuum pump 5, liquid 3 in a liquid storage tank 1 is sucked up through a suction pipe 6 as the pressure inside a suction tank 4 decreases, and is stored in the suction tank 4. At this time, the liquid inside a trap pipe 8 is sucked, flowing backward, toward the suction tank 4. However, continuous reverse flow of the liquid from a receiving tank 2 to the suction tank 4 does not occur because the height H3 of the trap pipe 8 is bigger than the range of lift H1 of the suction pipe 6, and balance is attained when liquid head pressure is produced in accordance with the degree of depressurization inside the suction tank 4. As the inside of the trap pipe 8 is sufficiently filled with the liquid stored in a lower tank 9, water seal in the trap pipe 8 is kept without the fear of becoming defective.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Field of Industrial Application) The present invention relates to a liquid transfer device, and in particular, it does not require movable equipment such as pumps or control valves in the wetted parts, making it extremely easy to maintain and manage. The present invention relates to an easy liquid transfer device.

(Prior Art) Many waste liquids discharged from chemical factories and nuclear power-related facilities are highly toxic and corrosive, and when processing them, it is necessary to be careful in handling the transfer. In particular, it is necessary to reduce radiation exposure as much as possible with respect to radioactive liquid waste discharged from nuclear-related facilities, and waste liquid treatment equipment is installed in a controlled area separated from general work areas.
In addition, they are often installed in locations where it is difficult to easily carry out maintenance and management work.

Such waste liquid treatment equipment also requires a transfer device to transfer the liquid from a low place to a high place, and conventionally, this transfer device has been equipped with a pump inside the piping system that distributes the liquid, as in the case of a normal chemical plant. It is composed of movable equipment such as a control valve and a control valve.

(Problem to be solved by the invention) However, in conventional transfer devices, movable equipment such as pumps and control valves come into direct contact with highly corrosive and toxic liquids, resulting in corrosion, damage, and performance deterioration of movable parts. However, it is necessary to periodically stop the device for maintenance inspection and parts replacement, which has the disadvantage that maintenance work requires a great deal of effort and time.

In particular, in transfer equipment that handles radioactive waste liquid, the radiation exposure of workers increases and the risk of direct contact with the waste liquid is high.
Some kind of countermeasure was desired.

The present invention has been made to solve the above-mentioned problems, and it is possible to simplify the configuration of the device without using equipment with moving parts in wetted parts, and to significantly reduce maintenance work. The purpose of the present invention is to provide a liquid transfer device that provides a liquid transfer device.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a liquid transfer device that transfers liquid from a liquid storage tank located at a low location to a receiving tank located at a high location. The present invention is characterized in that a tank is arranged and a pressure reducing device is provided for reducing the pressure of the suction tank and sucking the liquid in the liquid storage tank into the suction tank.

(Function) In the liquid transfer device having the above configuration, the pressure inside the suction tank is reduced by the pressure reducing device, so that the liquid stored in the liquid storage tank is sucked up into the suction tank.

The sucked up liquid is transferred to the head between the suction tank and the receiving tank (
Wave crest) difference causes the water to be transferred into the receiving tank by gravity.

As described above, according to the liquid transfer device of the present invention, it is possible to move from a low place to a high place by adjusting the pressure in the suction tank without disposing movable equipment such as a pump or a control valve in the liquid contact part of the liquid transfer path. liquid can be transferred to. Therefore, there is no damage or deterioration of the moving parts, and maintenance and inspection of the equipment is easy.
The device can be operated continuously for long periods of time.

Particularly in equipment that handles radioactive liquids, the radiation exposure of maintenance workers can be significantly reduced as maintenance and inspection time is shortened.

(Example) Next, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of a liquid transfer device according to the present invention.

That is, the liquid transfer device according to this embodiment is a liquid transfer device that transfers liquid 3 from a liquid storage tank 1 located at a low location to a receiving tank 2 located at a high location, in which a suction tank 4 is located at a higher location than the receiving tank 2. At the same time, a vacuum pump 5 is provided as a pressure reducing device that reduces the pressure of the suction tank 4 and sucks the liquid 3 in the liquid storage tank 1 into the suction tank 4.

The suction tank 4 and the liquid storage tank 1 are connected by a suction pipe 6, and the lower end of the suction pipe 6 is immersed in the liquid 3. The lower end nozzle 7 of the suction tank 4 and the receiving tank 2 are connected by a U-shaped trap pipe 8, and near the lower end of the trap pipe 8, there is a lower part where a sufficient amount of liquid can be stored to fill the trap pipe 8. A tank 9 is provided.

The end of the trap pipe 8 on the receiving tank 2 side is arranged to be open above the liquid level, and this structure prevents the liquid from flowing back from the receiving tank 2 to the suction tank 4 side.

In addition, in order to prevent liquid from flowing back through the trap pipe 8 from the receiving tank 2 side to the suction tank 4 side when the pressure inside the suction tank 4 is reduced by the vacuum pump 5, the height H3 of the trap pipe 8 is
is set larger than the lift height H) in the suction pipe 6.

In addition, a three-way valve 11 is installed in the pressure reducing pipe 10 that connects the suction tank 4 and the vacuum pump 5, and a pressure transmitter 12 is installed in the upper part of the suction tank 4 to detect and transmit the pressure inside the suction tank 4. An ultrasonic liquid level gauge 13 for measuring the liquid level inside the suction tank 4 is also provided. Furthermore, the pressure transmitter 12
A regulator 14 is provided that adjusts the opening direction of the three-way valve 11 based on the pressure signal from the ultrasonic liquid level gauge 13 and the liquid level signal from the ultrasonic liquid level gauge 13 .

When transferring the liquid 3 in the liquid storage tank 1 to the receiving tank 2, a step of sucking up the liquid 3 into the suction tank 4 is first performed.

That is, when the vacuum pump 5 is started with the three-way valve 11 driven and the pressure reducing pipe 10 communicated with the vacuum pump 5, as the pressure in the suction tank 4 is reduced, the liquid in the liquid storage tank 1 passes through the suction pipe 6. Liquid 3 is sucked up and stored in suction tank 4. At this time, the liquid in the trap pipe 8 is also sucked back to the suction tank 4 side, but since the height H3 of the trap pipe 8 is larger than the lifting height H1 of the suction pipe 6, the liquid in the trap pipe 8 is drawn from the receiving tank 2 side to the suction tank 4 side. The liquid does not continuously flow back, and is balanced when a liquid head pressure corresponding to the degree of vacuum in the suction tank 4 is generated. Further, since the liquid stored in the lower tank 9 sufficiently fills the trap pipe 8, there is no fear that the water seal in the trap pipe 8 will break.

The rise in the liquid level in the suction tank 4 is detected by the ultrasonic liquid level gauge 13. When a predetermined amount of liquid is stored in the suction bow tank 4, the three-way valve 11 is rotated by the regulator 14 so as to communicate with the atmosphere side, and the reduced pressure state in the suction tank 4 is released.

As a result, the liquid contained in the suction tank 4 passes through the trap pipe 8 and is discharged in the direction of the receiving tank 2.

This dispensing is done between the liquid level in the suction tank 4 and the trap pipe 8.
The head pressure (liquid head pressure) corresponding to the height difference (H + h - H3) with the open end of the head is caused by gravity flow.

Here, in order to suck up the liquid 3 from the liquid storage tank 1 through the suction pipe 6 into the suction tank 4 without causing the water seal to break in the trap pipe 8, the pressure inside the suction tank 4 must be
1 must be set within the range of formula (1) below.

P2-pH,>Pl>P3-pH2...(1)
Here, P2 is the pressure acting on the liquid level of the liquid storage tank 1, P3 is the pressure acting on the liquid level of the receiving tank 2, ρ is the specific gravity of the liquid, Hl is the lift of the suction pipe 6, and H2 is the lowest part of the trap pipe 8. This is the height from the bottom nozzle 7 of the suction tank 4 to the bottom nozzle 7 of the suction tank 4.

Further, while the pressure inside the suction tank 4 is maintained at P, the flow rate q1 of the liquid 3 discharged from the discharge nozzle 15 of the suction pipe 6 is expressed by the following equation (2).

l (2) Here, 1 is the flow coefficient of the discharge nozzle 15 and the suction pipe 6 as a whole, a is the liquid passage cross-sectional area of the discharge nozzle 15, and g is the weight acceleration.

When the liquid 3 flowing in from the discharge nozzle 15 reaches a predetermined level, the liquid level is detected by the ultrasonic level gauge 13 and the level detection signal is transmitted to the regulator 14. The regulator 14 sends a rotation command to the three-way valve 11, and the three-way valve 11 operates to communicate with the atmosphere, so the reduced pressure in the suction tank 4 is released and Pl becomes equal to atmospheric pressure. At this time, if both the liquid storage tank 1 and the receiving tank 2 are tanks open to the atmosphere,
P,=P2=P3.

Therefore, the flow rate q2 of the liquid flowing out from the open end of the trap pipe 8 on the receiving tank 2 side is given by the following equation (3).

[Margin below]

(3) Here, 2 is the flow coefficient of the entire trap pipe 8, b is the liquid passage cross-sectional area at the lower end nozzle 7, h is the height from the lower end nozzle 7 of the suction tank 4 to the liquid level, H3 is the height from the lowest part of the trap pipe 8 to the open end on the receiving tank 2 side.

When the liquid level in the suction tank 4 drops to the lower end nozzle 7, the vacuum pump 5 is started again to lower the pressure in the tank to Pl shown by equation (1), and the liquid is removed from the liquid storage tank 1. Return to the process of sucking up and frying.

Here, the maximum set liquid level (h ) aX in the suction tank 4 is determined by the structure of the suction tank 4. Since the liquid capacity at this highest set liquid level h is constant fiaK, the total amount of liquid transferred can also be calculated by measuring the number of times the above-mentioned suction step is performed.

The pressure transmitter 12 confirms that the pressure in the suction tank 4 is within the range of predetermined operating conditions, and also sends an abnormality signal to the regulator 14 when a pressure abnormality occurs, and closes the three-way valve 11 to the atmosphere. It also has a function of rotating the suction tank 4 toward the communication side, returning the pressure in the suction tank 4 to atmospheric pressure, and stopping the transfer device.

When the liquid transfer operation is completed and the pressure in the suction tank 4 is returned to atmospheric or environmental pressure, the liquid level in the trap pipe 8 drops to the same level as the open end on the receiving tank 2 side and becomes balanced. Since liquid remains in the U-shaped trap pipe 8 and the lower tank 9, the space between the receiving tank 2 and the suction tank 4 is always kept in a water-sealed state.

As described above, according to the liquid transfer device according to the present embodiment, by adjusting the pressure inside the suction tank 4, the liquid 3 can be transferred from the liquid storage tank 1 located at a low location to the receiving tank 2 located at a high location. It can be transported efficiently.

In particular, in the device of this embodiment, there is no need to provide movable devices such as pumps and control valves in the liquid contact parts, and the device configuration is extremely simplified. Therefore, operation and maintenance of the device is extremely easy, and continuous operation can be continued for a long period of time.

In this embodiment, a lower tank 9 is provided at the bottom of the trap pipe 8, so that even if the liquid in the trap pipe 8 is sucked up by the reduced pressure in the suction tank 4, the trap pipe 8 will not break the water seal. Be careful not to wake up the lower tank 9.
The structure is such that more liquid is replenished into the tube.

However, by making the length of the trap tube sufficiently long and increasing the amount of liquid held within the tube,
The lower tank can also be omitted.

On the other hand, the trap pipe can be made shorter by interposing a check valve in the middle of the trap pipe.

〔Effect of the invention〕

As explained above, according to the liquid transfer device according to the present invention, it is possible to move the liquid from a low point to a high point by adjusting the pressure inside the suction tank without disposing movable equipment such as a pump or a control valve on the liquid contact part of the liquid transfer path. liquid can be transferred to the location. Therefore, the movable parts are not damaged or deteriorated, maintenance and inspection of the device is easy, and the device can be operated continuously over a long period of time.

Particularly in equipment that handles radioactive liquids, the radiation exposure of maintenance workers can be significantly reduced as maintenance and inspection time is shortened.

2...Pressure transmitter, 13...Ultrasonic liquid level gauge, 14.
... Regulator, 15... Discharge nozzle.

8 applicant agent Hatano long

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a liquid transfer device according to the present invention.

Claims (1)

[Claims] In a liquid transfer device that transfers liquid from a liquid storage tank located at a low location to a receiving tank located at a high location, a suction tank is located at a higher location than the receiving tank, and the suction tank is depressurized to remove the liquid in the liquid storage tank. A liquid transfer device characterized in that a pressure reducing device for suction is provided in a suction tank.