JPH04242586A - Internal pressure retaining device for container - Google Patents

Abstract

PURPOSE:To provide a device to retain internal pressure of a container in a specified range, which has a simple structure and can be provided at a low cost, has a high reliability and airtightness, and of which maintenance check-up is easy. CONSTITUTION:The title device is equipped with a pot 2 in which a sealing liquid is placed, and a partitioning member 5 which devides the inside of the pot 2 into a first chamber 3 and a second chamber 4. A communicating port 7 which communicates between the first chamber 3 and the second chamber 4 is provided under the liquid level of the sealing liquid 6. The first chamber 3 is communicated with a container T of which the internal pressure is retained, and the second chamber 4 is communicated with, e.g. atmosphere to keep a fixed pressure. When the internal pressure of the container T ascends, and the liquid level of the sealing liquid 6 in the first chamber 3 descends to the communicating port 7, the inside of the container T and the second chamber 4 are communicated, and the internal pressure of the container T is prevented from ascending. When the internal pressure of the container T descends, and the liquid level of the sealing liquid 6 of the second chamber descends to the communicating port, and inside of the container T and the second chamber are communicated, and the internal pressure of the container T is prevented from descending.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an internal pressure maintaining device for containers, and is suitable for maintaining the internal pressure of containers that store relatively high viscosity liquids such as chemical tanks or liquids that undergo chemical deterioration due to temperature. It is.

0002

[Prior Art] For example, in a chemical tank, the internal pressure of the tank may rise and cause an explosion, the internal pressure of the tank may fall below the outside pressure and cause the tank to collapse, or air may enter the tank and the quality of the stored liquid may deteriorate. It is necessary to prevent this.

[0003] Therefore, by supplying nitrogen or the like at a constant pressure into the tank, the internal pressure of the tank is kept constant and the liquid stored in the tank is sealed to prevent it from coming into contact with air.

[0004]However, supplying the stored liquid into the tank,
When the stored liquid is withdrawn, the liquid stored in the tank changes, and when the outside temperature changes, the stored liquid and stored liquid vapor expand and contract, causing the tank internal pressure to fluctuate. Resulting in.

[0005] Therefore, it has been conventional practice to maintain the internal pressure of the tank at a constant level by attaching a breather valve to the tank. The breather valve includes a valve seat and a valve body placed on the upper end of the valve seat, and the valve body moves up and down to open and close a contact portion with the valve seat. As a result, when the internal pressure of the tank changes, the valve body moves up and down, and the space between the valve body and the valve seat opens, allowing the inside of the tank to communicate with the atmosphere, and keeping the internal pressure of the tank constant.

[0006] Furthermore, a seal pot device 101 as shown in FIG. 8 is used to maintain the internal pressure of the tank T below a certain level. This seal pot device 101
is pot 104, this pot 104 and tank T
and a vent 106 that communicates the inside of the pot 104 with the atmosphere. Piping 105 communicates the tank T and the pot 104.
The lower end of the pot 104 side is located at a depth h from the liquid level of the sealing liquid 103 placed in the pot 104 .

According to the seal pot device 101,
When the internal pressure of the tank T increases and reaches a certain pressure corresponding to the water level h of the sealing liquid 103 with respect to the pipe 105,
The gas inside the tank T is blown out into the sealing liquid 103, and the inside of the tank T is communicated with the atmosphere via the vent 106. This prevents the internal pressure of the tank T from exceeding a certain pressure.

Furthermore, a seal pot device 110 as shown in FIG. 9 is used to maintain the internal pressure of the tank T within a certain range. This seal pot device 110
is equipped with a first pot 111 and a second pot 112 . The first pot 111 is connected to the tank T via a pipe 113. That is, piping 113
One end of the pipe 113 is connected to the tank T, and the other end of the pipe 113 is bifurcated, and one of the forked parts 114 is connected to the first pot 1.
11 , and the other forked portion 117 is connected to the second pot 112 . The lower end of one of the forked parts 114 connected to the first pot 111 is located h1 from the liquid level of the sealing liquid 115 placed in the first pot 111.
It is located at the depth of. Further, the first pot 111 is communicated with the atmosphere via a vent 116.

The second pot 112 is communicated with the tank T by connecting the other bifurcated portion 117 of the pipe 113 as described above. Further, a sealing liquid 118 is placed in the second pot 112, and this sealing liquid 118
A nitrogen supply pipe 119 is inserted into. This nitrogen supply pipe 119 is connected to a check valve 120 from a nitrogen source (not shown).
Nitrogen is supplied at a constant pressure via the The lower end of this nitrogen supply pipe 119 is located at a distance of h2 from the liquid level of the sealing liquid 118.
It is located at the depth of.

According to the seal pot device 110,
When the internal pressure of the tank T increases and reaches a certain pressure corresponding to the water level h1 of the sealing liquid 115 with respect to the piping 113 in the first pot 111, the gas inside the tank T blows out into the sealing liquid 115, and the inside of the tank T will communicate with the atmosphere via vent 116. This prevents the internal pressure of the tank T from exceeding a certain level.

[0011] Also, the internal pressure of the tank T decreases, and the sealing liquid 1 to the supply pipe 119 in the second pot 112 decreases.
When the pressure reaches a constant pressure corresponding to the water level h2 of 18, the nitrogen supplied from the supply pipe 119 is blown into the sealing liquid 118, and is supplied to the inside of the tank T via the pipe 113. This prevents the internal pressure of the tank T from dropping below a certain level. In addition, each pot 1
Water level gauges 121, 122 are attached to 11, 112.

0012

SUMMARY OF THE INVENTION In conventional breather valves, the vapor of the liquid stored in the tank sometimes condenses and accumulates on the valve seat. In addition, in the case of chemical tanks, the stored liquid may be supplied into the tank through a pipe, and at that time, nitrogen or the like is blown into the pipe to prevent the stored liquid from remaining in the pipe. Liquid may squirt out. In such cases, the ejected liquid becomes mist and may accumulate on the valve seat.

When the stored liquid in the tank accumulates on the valve seat in this way, the viscosity of the stored liquid creates a bonding force between the valve seat and the valve body, which causes the valve body to operate in order to keep the internal pressure of the tank constant. There was a problem in that the pressure rose and the valve could no longer function as a breather valve. In particular, in the case of chemicals whose freezing point is above room temperature, the area around the breather valve is heated to prevent them from coagulating, but such heating can chemically alter the liquid through polymerization and increase its viscosity. In such cases, the degree of adhesion between the valve seat and the valve body becomes large, resulting in a lack of reliability.

Further, according to the conventional seal pot device 101 shown in FIG. 8, although it is possible to prevent the internal pressure of the tank T from exceeding a certain pressure, the tank In some cases, it may not be possible to prevent the internal pressure of T from becoming lower than a certain pressure, and the internal pressure of the tank becomes negative and the tank collapses, or the sealing liquid 103 flows backward through the piping 105 and enters the tank T. There is a problem.

Conventional seal pot device 110 shown in FIG.
In this case, the internal pressure of the tank T can be maintained within a certain range, but two pots, the first pot 111 and the second pot 112 , and a large number of piping are required, which increases the size of the device and increases the cost. Furthermore, it is necessary to manage the sealing liquid level for each individual pot, which requires time and effort for maintenance and inspection.

SUMMARY OF THE INVENTION An object of the present invention is to provide an internal pressure maintaining device for a container that can effectively solve the problems of the prior art described above with a simple structure.

[0017]

[Means for Solving the Problems] The present invention is characterized by a device for maintaining the internal pressure of a container within a certain range,
It is equipped with a pot for storing sealing liquid, and a partition member for partitioning the inside of the pot into a first chamber and a second chamber, and a communication port that communicates the first chamber with the second chamber is for storing sealing liquid to be placed in the pot. The first chamber is in communication with the inside of the container, and the second chamber is maintained at a constant pressure.

[0018] It is preferable that a notch is formed at the lower end of the partition member, and this notch constitutes the upper part of the communication port.

[0019] It is preferable that the mounting position of the partition member is adjustable so that the volume ratio of the first chamber and the second chamber can be changed.

[0020]

[Function] According to the structure of the present invention, when the internal pressure of the container increases, the internal pressure of the first chamber of the pot communicated with this container increases, so that the sealing liquid in the first chamber passes through the communication port. The liquid flows into the second chamber, and the level of the sealing liquid in the first chamber falls while the level of the sealing liquid in the second chamber rises. When the internal pressure of the container exceeds a certain level, the liquid level of the sealing liquid in the first chamber drops to the position of the communication port, and the gas inside the first chamber blows out into the sealing liquid in the second chamber. The interior will communicate with the second chamber of the pot. Then, the second pot
Since the chamber is maintained at a constant pressure, the internal pressure of the container is prevented from rising above the constant pressure.

Furthermore, when the internal pressure of the container decreases, the sealing liquid in the second chamber flows into the first chamber through the communication port, and as the level of the sealing liquid in the first chamber rises, the sealing liquid in the second chamber also increases. The liquid level drops. When the internal pressure of the container drops below a certain level,
The liquid level in the second chamber drops to the position of the communication port, and the gas inside the second chamber is blown out into the sealing liquid in the first chamber, so that the inside of the container communicates with the second chamber of the pot. Then, since the second chamber of the pot is maintained at a constant pressure, the internal pressure of the container is prevented from dropping below a constant level.

Furthermore, when the gas in one chamber in the pot blows out into the seal liquid in the other chamber, if a large amount of gas blows out all at once, the surface of the seal liquid in the other chamber bubbles violently, creating mist. However, there is a risk that this mist may enter the container or scatter outside the pot. Therefore, by configuring the upper part of the communication port with a notch formed at the lower end of the partition member, the horizontal width of the communication port that communicates the first chamber and the second chamber is reduced at the upper end, and a large amount of gas can be released at once. is prevented from blowing out into the sealing liquid, and mist can be prevented from being generated due to violent bubbling on the surface of the sealing liquid.

Furthermore, since the set value of the holding pressure of the container is determined by the volume ratio of the first chamber and the second chamber, by changing the mounting position of the partition wall and changing the volume ratio of both chambers, The set value of the internal pressure can be changed and adjusted.

[0024]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The internal pressure maintaining device 1 shown in FIGS. 1 to 4 is as follows:
For example, it is used to maintain the internal pressure of a container such as a chemical tank T within a certain range. This internal pressure holding device 1 includes a pot 2 and a first chamber 3 that connects the inside of this pot 2.
and a partition member 5 that partitions the chamber into a second chamber and a second chamber. In this embodiment, the pot 2 has a rectangular parallelepiped shape. The shape of the pot 2 is not particularly limited, and may be cylindrical, for example. Further, the material of the pot 2 is not particularly limited, and it can be manufactured using metal, vinyl chloride, plastic, or the like. In order to facilitate internal inspection, it is preferable to use transparent hard vinyl chloride, for example.

A sealing liquid 6 is placed in the pot 2 . The type of this sealing liquid 6 is not particularly limited, and may be water, for example.Also, if mixing with the liquid in the tank T is undesirable, it may be the same as the liquid in the tank T. . Furthermore, if the freezing point of the liquid in the tank T is high, the mist that enters the first chamber 3 of the pot 2 may solidify and form a solid layer covering the sealing liquid 6. . To prevent this, pot 2
It is best to keep it above a certain temperature by covering it with a heating jacket, for example. At this time, in order to prevent the sealing liquid 6 from evaporating, it is preferable to add to the sealing liquid 6 a substance that has a low freezing point, is insoluble in water, and is liquid even at room temperature, such as liquid paraffin.

A communication port 7 communicating the first chamber 3 and the second chamber 4 is provided below the level of the sealing liquid 6. In this embodiment, the partition member 5 has a rectangular plate shape, and its upper end is joined to the inner surface of the upper wall of the pot 2, and its side ends are joined to the inner surface of the side wall of the pot 2. A communication port 7 is provided between the lower end of the partition member 5 and the upper surface of the bottom wall of the pot 2.

[0028] The first chamber 3 of the pot 2 is connected to the piping 8.
It is communicated with the inside of the tank T via. Further, the second chamber 4 of the pot 2 is maintained at atmospheric pressure by being communicated with the atmosphere through a vent 9. Note that the pipe 8 is connected to the pot 2 through a flange 10 and to the tank T through a flange 11. Also,
The vent 9 is connected to the pot 2 via a flange 12.

According to the internal pressure holding device 1, the tank T
When the internal pressure of the pot 2 is equal to the atmospheric pressure, the liquid level of the sealing liquid 6 in the pot 2 is equal in the first chamber 3 and the second chamber 4, as shown in FIG. From this state, tank T
As the internal pressure increases, the level of the sealing liquid 6 in the first chamber 3 falls and the level of the sealing liquid 6 in the second chamber 4 rises, as shown in FIG. When the internal pressure of the tank T exceeds a certain level, the level of the sealing liquid 6 in the first chamber 3 drops to the position of the communication port 7. Then, the gas in the first chamber 3 blows out into the seal liquid 6 in the second chamber 4, becomes bubbles, rises in the seal liquid 6 in the second chamber, and reaches the second chamber 4. This allows the inside of the tank T to communicate with the atmosphere, and prevents the pressure inside the tank T from rising above a certain level.

Next, when the internal pressure of the tank T becomes negative, the level of the sealing liquid 6 in the second chamber 4 decreases and the level of the sealing liquid 6 in the first chamber 3 decreases as shown in FIG. Rise. Then, when the internal pressure of the tank 2 becomes below a certain level, the liquid level of the sealing liquid 6 in the second chamber 4 drops to the position of the communication port 7. Then,
The gas in the second chamber 4 blows out into the seal liquid 6 in the first chamber 3, becomes bubbles, rises in the seal liquid 6 in the first chamber, and reaches the inside of the first chamber 3. This allows the inside of the tank T to communicate with the atmosphere, and prevents the pressure inside the tank T from dropping below a certain level.

A specific example of setting the volume ratio of the first chamber 3 and the second chamber 4 and the liquid level of the sealing liquid 6 in the internal pressure holding device 1 will be shown below.

In FIG. 1, the dimension of the pot 2 in the direction perpendicular to the plane of the paper is taken as a unit length, and the cross-sectional area of the first chamber 3 is given as Dmm2.
, the cross-sectional area of the second chamber 4 is dmm2. Further, the sealing liquid 6 is water.

Furthermore, when the internal pressure of the tank T is at atmospheric pressure, the depth from the liquid level of the sealing liquid 6 in the first chamber 3 to the communication port 7 is Hmm, and the depth from the liquid level of the sealing liquid 6 in the second chamber 4 to the communication port 7 is Hmm. The depth to the mouth is hmm. Also, when the liquid level of the sealing liquid 6 in the second chamber 4 falls to the communication port 7,
The liquid level rising distance of sealing liquid 6 is am, and the first chamber 3 is
The distance by which the liquid level of the sealing liquid 6 in the second chamber 4 rises when the liquid level of the sealing liquid 6 in the second chamber 4 falls to the communication port 7 is defined as bmm. Further, let x be the sum of a and H, and y be the sum of b and h. Then, the upper limit of the internal pressure of tank T is 500 mmH2O,
The lower limit is set to -150 mmH2O. As a result, the following formula is established.

h+b=(hd+HD)/d ■ H+a=(HD+hd)/D ■ H=h
■h+b=y=500 ■H+a=
x=150 ■Dx=dy
■

[0035] ■
From the formula, d=0.3 D
■

According to this formula (■), the first chamber 3 and the second chamber 4
The volume ratio of is determined. From ■■■■ formula or ■■■■ formula, H=h=115mm
■

The amount of sealing liquid 6 to be put into pot 2 is determined from this equation (2). That is, the volume ratio of the first chamber 3 and the second chamber 4 and the amount of the sealing liquid 6 are determined according to the range in which the internal pressure of the tank T is maintained. In this case, when using something other than water as the sealing liquid, the amount of the sealing liquid is increased or decreased depending on the specific gravity.

Note that the present invention is not limited to the above embodiments.

For example, in the above embodiment, the second chamber is communicated with the atmosphere, but the second chamber only needs to be maintained at a constant pressure, and nitrogen at a constant pressure may be supplied to the second chamber. In this case, for example, a pipe for supplying nitrogen at a constant pressure is connected to the second chamber, a check valve is provided in the middle of the pipe to prevent nitrogen from flowing back, and a check valve is installed between the check valve and the second chamber. A relief valve is provided to prevent the pressure in the second chamber from exceeding a certain level.

The capacity of the pot 2 may be determined depending on the capacity of the tank T, the amount of gas inserted into the tank T, and other uses.

The internal pressure maintaining device according to the present invention can also be used to maintain the internal pressure of containers other than chemical tanks within a certain range.

Further, in the above embodiment, the first chamber 3 and the second chamber 4
The width in the horizontal direction of the communication port 7 that communicates between the By doing so, the horizontal width of the communication port 7 may be made shorter on the upper side. As a result, the liquid level of the sealing liquid 6 is lowered to the position of the communication port 7, and when the gas in one chamber is blown into the sealing liquid 6 in the other chamber, a large amount of gas is not blown in all at once. Generation of mist due to violent bubbling of the surface of the sealing liquid 6 is reduced, and intrusion of the sealing liquid into the tank T and scattering of the sealing liquid to the outside of the pot 2 are prevented. The shape of this notch 13 is not particularly limited, and may be, for example, a rectangle as shown in FIG. 5, a triangle as shown in FIG. 6, or a semicircle as shown in FIG.

Further, the shape of the communication port 7 is not limited to the rectangular shape as in the above embodiment, but may be circular, for example.

In addition, in order to prevent the mist generated inside the pot 2 from entering the tank T, a demister is installed above the surface of the sealing liquid 6 to prevent entrainment, as shown by the imaginary line in FIG. 14 may be provided. Furthermore, in order to prevent the mist from scattering to the outside of the pot 2, a demister 14 may also be provided in the second chamber.

Furthermore, the tank T by the internal pressure holding devices 1 and 2
The range in which the internal pressure of the partition member 5 is maintained is determined by the volume ratio between the first chamber 3 and the second chamber 4 and the amount of sealing liquid. For example, the partition member 5 may be attached to the pot 2 via a rail so as to be movable in the left-right direction in FIG.

[0046]

[Effects of the Invention] According to the present invention, the internal pressure of the container is maintained within a certain range by utilizing the fact that the liquid level of the sealing liquid in the pot fluctuates depending on the internal pressure of the container. It operates more reliably and accurately than those that maintain pressure through operation, and is highly airtight. Moreover, since the internal pressure of the container can be maintained within a certain range with a simple structure using a single pot, the device can be downsized and manufacturing costs can be reduced. Also,
Maintenance and inspection such as sealing liquid level management becomes easier.

Furthermore, by forming the upper part of the communication port with a notch formed at the lower end of the partition member, it is possible to prevent mist from being generated due to violent foaming of the sealing liquid surface, and to prevent the sealing liquid from entering the container. This can prevent scattering to the outside of the pot.

[0048] Furthermore, by changing the mounting position of the partition member and making the volume ratio of the first chamber and the second chamber in the pot different, the set value of the internal pressure holding range of the container can be easily changed. be able to.

[Brief explanation of the drawing]

[Fig. 1] An explanatory diagram showing the state of the internal pressure holding device according to the embodiment of the present invention when the internal pressure of the tank is atmospheric pressure.

[Figure 2]
An explanatory diagram showing the state of the internal pressure holding device according to the embodiment of the present invention when the internal pressure of the tank rises from atmospheric pressure

[Fig. 3] An explanatory diagram showing the state of the internal pressure holding device according to the embodiment of the present invention when the tank internal pressure is negative pressure.

[Fig. 4] A perspective view of an internal pressure holding device according to an embodiment of the present invention.

[Fig. 5] A sectional view showing a modification of the notch of the partition member according to the embodiment of the present invention.

[Fig. 6] A sectional view showing a modification of the notch of the partition member according to the embodiment of the present invention.

[Fig. 7] A sectional view showing a modification of the notch of the partition member according to the embodiment of the present invention.

[Fig. 8] Explanatory diagram of a seal pot device according to a conventional example

[
Figure 9: Explanatory diagram of a conventional seal pot device

[Explanation of symbols]

1 Internal pressure holding device T Tank (container) 3 First room 4 2nd room 5 Partition member 6 Seal liquid 7 Communication port

Claims (3)

[Claims] 1. A device for maintaining the internal pressure of a container within a certain range, comprising: a pot containing a sealing liquid; and a partition member that partitions the inside of the pot into a first chamber and a second chamber; A communication port communicating the chamber and the second chamber is provided below the liquid level of the sealing liquid placed in the pot, the first chamber communicates with the inside of the container, and the second chamber is kept at a constant pressure. A device for maintaining internal pressure of a container. 2. The internal pressure maintaining device for a container according to claim 1, wherein a notch is formed at the lower end of the partition member, and this notch constitutes an upper part of the communication port. 3. The container according to claim 1 or 2, wherein the mounting position of the partition member can be changed and adjusted so that the volume ratio of the first chamber and the second chamber can be changed. Internal pressure holding device.