JPS6128796Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a tank system that needs to isolate the stored liquid from moisture in the atmosphere. It relates to an overflow device that has the function of automatically discharging water to the outside and normally shutting off outside air.

For example, when storing a hygroscopic liquid such as concentrated sulfuric acid in a tank open to the atmosphere, the concentration of the stored liquid may change due to absorption of moisture from the atmosphere.
In addition, lines that are open to the atmosphere should be equipped with dehumidifiers that have dehumidifying and sealing functions, or lines that are not normally used should be equipped with a dehumidifying device that has a dehumidifying function and a sealing function. A shutoff valve is installed and closed except when necessary. The system around these tanks and the structure of the dehumidifier will be explained using FIGS. 1, 2, and 3, taking the case of concentrated sulfuric acid as an example.

The concentrated sulfuric acid intermediate storage tank 1 receives supply from a large capacity storage tank through sulfuric acid supply pipes 101 and 103 by a sulfuric acid supply pump 102. A sulfuric acid transfer pump 112 supplies sulfuric acid to a consumer through sulfuric acid transfer pipes 111 and 113.
The intermediate storage tank 1 is equipped with a level switch,
This is a system that automatically fills the tank depending on the liquid level in the tank. That is, when the liquid level in the tank decreases and reaches the set low level, the level switch low 121 operates and the above-mentioned filling pump 10
2 to start automatically. Next, due to the rise in the liquid level,
When the high level is reached, the level switch height 122 is operated to automatically stop the sulfuric acid supply pump 102 as well.

The intermediate storage tank 1 includes a sulfuric acid supply pump 102.
Alternatively, as the freeboard volume inside the tank changes due to changes in the liquid level due to the operation of the sulfuric acid transfer pump 112, the intake and exhaust pipe 2 for intake and exhaust of air changes.
is provided. In this intermediate storage tank 1,
A dehumidifying device 5 is provided to prevent moisture from being brought into the atmosphere during suction and exhaustion, and to prevent moisture from entering due to contact with outside air when the liquid level is fixed. Furthermore, the tank has an overflow pipe 3, which should normally be provided in case of an abnormal rise in the liquid level. Although this line is open to the drain treatment device in the tank equipment, it is necessary to take quality control measures similar to the intake and exhaust pipes, and a shutoff valve 4 that is normally closed is provided. However, in the case of a system that automatically fills the intermediate storage tank 1 and transfers it for consumption, it is difficult to open and close the cut-off valve 4 when necessary to prevent an abnormal rise in the liquid level.
Very difficult.

Therefore, as shown in FIG. 2, the dehumidifier 5 installed in the intake/exhaust pipe 2 is shared and connected to the inlet of the dehumidifier 5 of the intake/exhaust pipe 2 to remove moisture from the overflow pipe 3. It has also been considered to prevent infiltration and to leave the overflow line open without closing it.

An example of the structure of this dehumidifying device 5 is as shown in FIG. 3, in which a desiccant 11 and a seal oil 14 are installed. Therefore, when the freeboard pressure becomes negative, the inside of the desiccant holding tube 12 also becomes negative via the intake and exhaust pipes 2 and 10. The lower end of the desiccant holding tube 12 has a liquid level adjusted so that it reaches below the liquid level of the seal oil 14 in the seal box 13 during static operation, and is normally isolated from the outside air by the seal oil 14.

As described above, when the inside of the desiccant holding tube 12 is under negative pressure, the liquid level of the seal oil 14 inside the desiccant holding tube 12 rises, and the liquid level on the outside air side decreases. Here, when the liquid level on the outside air side drops to a point other than the lower end of the desiccant holding pipe 12, outside air starts to be sucked into the desiccant holding pipe 12, and moisture is contained in the intermediate storage tank 1 through the intake/exhaust pipe 2. Air flows in. Conversely, when exhausting air from the intermediate storage tank 1, as the liquid level in the tank rises, the freeboard air pushes down the seal oil level in the desiccant holding tube 12, the seal is broken, and it is discharged to the outside air side. .

As in FIG. 2, the overflow pipe 3 is connected to the intake and exhaust pipes. In this case, when the liquid level in the intermediate storage tank 1 rises abnormally, sulfuric acid flows out into the overflow pipe 3 and flows into the dehumidification device 5 via the intake and exhaust pipe 2. This overflow fluid flows into the seal box 13 via the desiccant holding tube 12 in the dehumidifier 5. However, this has the disadvantage that sulfuric acid flows into the desiccant 11 and seal oil 14 in the dehumidifying device 5, making it unusable and impairing the dehumidifying function, which is the original purpose.

The purpose of this invention is to automatically drain the overflow fluid to the outside only in the event of an overflow to the overflow line of a tank that needs to isolate the stored liquid from moisture in the atmosphere. By having the function of blocking
This prevents the liquid level in the tank from rising abnormally.

The present invention connects an overflow line to a dehumidifying device installed in the intake and exhaust line of the tank to prevent an abnormal rise in the tank liquid level. In order to eliminate contact between this overflow line and the sealant, a shrinkable membrane such as butyl rubber is installed, which usually
The sealant's own weight pushes the membrane and closes the overflow line, and in the event of an overflow, the overflow fluid settles due to the difference in specific gravity between the overflow fluid and seal oil, which is used to discharge the fluid to the outside. It is something.

An embodiment of the invention is shown in FIG. 4, and an overflow device is shown in FIG. In FIG. 4, the overflow pipe 3 shown in FIGS. 1 and 2 is connected to a dehumidifier, and an overflow outlet pipe is installed from the dehumidifier.

The intermediate storage tank 1 includes a sulfuric acid supply pump 102.
The sulfuric acid is supplied from a large-capacity tank and pumped into the tank. Further, sulfuric acid is supplied from the intermediate storage tank 1 to the consumer by a sulfuric acid transfer pump 112. This operation is automatically performed by the level switches 121 and 122 of the intermediate storage tank 1, and an abnormal rise in the liquid level in the tank is considered. During this abnormal rise, the liquid in the intermediate storage tank 1 is guided to the overflow device 6 through the overflow pipe 3.

The overflow device 6 is a device that includes the dehumidification device 5 with the function of an overflow line. Normally, seal oil 14
Due to its own weight, the contractible butyl rubber membrane 21 is pushed against the wall of the seal box 13, closing the overflow fluid inlet 20 and the overflow fluid outlet 22, and blocking the outside air.
At the time of overflow, the overflow fluid flows into the overflow device 6 through the overflow fluid inlet 20 and is pushed into the butyl rubber membrane 21 which has a contractility to prevent contact with seal oil. Here, if the overflow fluid is sulfuric acid and the sealant is oil, the specific gravity of sulfuric acid is 13.4, whereas the seal oil is lighter at 0.85 to 0.97. Overflow fluid outlet 22 installed at the bottom
The water is discharged from the overflow outlet pipe 7 into the drainage pit. After discharge, the seal oil's own weight isolates it from the outside air, as in normal times.

According to the embodiment of the present invention, in response to an abnormal rise in the liquid level in the intermediate storage tank 1, the overflow line is normally closed, and only when an overflow occurs, the overflow fluid is automatically discharged to the outside. A shutoff valve is installed in the overflow line so that there is no need to open or close the valve at the time of overflow, and the function of the dehumidifier 5 is not impaired.

Taking sulfuric acid as an example, FIG. 6 shows a case where a sulfuric acid dilution tank 131 is installed at the consumption point of the intermediate storage tank 1. The sulfuric acid dilution tank 131 is a tank open to the atmosphere, and is filled with dilution water from a dilution water pipe 134. Thereafter, the sulfuric acid transfer pump 112 is operated by the level switch 132, and sulfuric acid is charged therein.
When the concentration in the sulfuric acid dilution tank 131 reaches the specified value,
The concentration meter 133 stops the operation of the sulfuric acid transfer pump 112 and keeps the concentration in the sulfuric acid dilution tank 131 constant. Here, the intermediate storage tank 1 that supplies sulfuric acid to the sulfuric acid dilution tank 131 is usually equipped with the overflow device 6 of the present invention. The overflow fluid that has passed through the overflow device 6 is led into the sulfuric acid dilution tank 131 via the overflow outlet pipe 7.

This not only reduces the need for wastewater treatment such as neutralization by discharging sulfuric acid to the outside, but also reduces the risk of discharging chemicals to the outside.

According to the present invention, the tank is installed in the overflow line of a tank that needs to be separated from the stored liquid and moisture in the atmosphere, the overflow is automatically performed, and normally, by being separated from the outside air, Not only does it not impair its function as a dehumidifying device, but it also eliminates the need to operate a shutoff valve in the event of an overflow.

[Brief explanation of drawings]

Figure 1 is a system diagram in which a shutoff valve is installed in the overflow line in a tank system that requires isolation from outside air.
Figure 2 is a system diagram of the overflow line connected to the intake and exhaust pipes in a tank system that requires isolation from outside air.
Figure 3 is a structural diagram of the dehumidification device, Figure 4 is a system diagram of an overflow device installed in the overflow line in a tank system that requires isolation from outside air, and Figure 5 is a structural diagram of the overflow device. , FIG. 6 is a system diagram in which a dilution tank is installed at the consumption site in a tank system that requires isolation from outside air. 1... Intermediate storage tank, 2... Intake and exhaust pipe, 3...
... Overflow pipe, 102 ... Sulfuric acid supply pump, 112 ...
... Sulfuric acid transfer pump, 5 ... Dehumidification device, 6 ... Overflow device, 11 ... Desiccant, 14 ... Seal oil, 21
...Butyl rubber membrane, 131...Sulfuric acid dilution tank.

Claims (1)

[Scope of utility model registration request] In an overflow device that drains liquid above a specified liquid level from a tank for storing liquid through an overflow pipe, an intake and exhaust pipe that communicates the inside of the storage tank with the atmosphere;
A dehumidification device installed in the intake and exhaust pipe, which removes moisture from the atmosphere when air is taken in and exhausted, and seals the intake and exhaust pipe with a seal oil having a specific gravity smaller than that of the liquid in a static state when air is not taken in and exhausted. A shrinkable membrane provided in the dehumidification device distinguishes the side where seal oil is present and the side where no seal oil is present, and the overflow pipe is connected to this side where seal oil is not present. The weight of the oil pushes the shrinkable membrane against the inner wall of the dehumidifier on the side where no seal oil is present, closing the overflow line.
An overflow device characterized in that, at the time of overflow, the liquid having a specific gravity greater than that of the seal oil separates the contractile membrane from the inner recess and opens the overflow line.