JP2024069047A - Deaeration device - Google Patents

Abstract

An object of the present invention is to provide a degassing device that can reduce the labor required for maintenance.
[Solution] The degassing device (1) is positioned above the liquid level (L3) of a liquid (L2) stored in a liquid tank (L1) and is equipped with an outlet (10) that ejects liquid containing dissolved gas from above the liquid surface, and an impact plate (20) that collides the liquid ejected from the outlet with the liquid, scattering it and causing it to fall onto the liquid surface.
[Selected Figure] Figure 1

Description

The present invention relates to a degassing device.

Conventionally, various techniques are known as methods for removing dissolved gas from a liquid. For example, Patent Documents 1 and 2 disclose a technique for removing carbon dioxide from the water to be treated by spraying the water in which carbon dioxide is dissolved from a nozzle. Furthermore, Patent Documents 3 and 4 disclose a technique for removing exhaust gases from fish and shellfish contained in the water by blowing air or the like into the water in which the fish and shellfish are kept.

JP 2012-120993 A Japanese Patent Application Laid-Open No. 7-178387 Japanese Patent Application Laid-Open No. 5-3735 Patent No. 6858996

However, the technology of spraying a liquid containing dissolved gas from a nozzle has the problem that the nozzle is easily clogged, and the labor required for maintenance is large. In addition, the technology of blowing air or the like into a liquid containing dissolved gas has the problem that dirt is easily accumulated in the air blowing section of the air diffuser, etc., and the labor required for maintenance is large. One aspect of the present invention aims to realize a degassing device that can reduce the labor required for maintenance.

To solve the above problems, a degassing device according to one aspect of the present invention includes an outlet that is disposed above the liquid surface of the liquid stored in a liquid tank and that ejects the liquid containing dissolved gas from above the liquid surface, and an impact plate that is disposed between the outlet and the liquid surface and that causes the liquid ejected from the outlet to collide with the liquid, scattering the liquid and causing it to fall onto the liquid surface.

According to one aspect of the present invention, it is possible to realize a degassing device that can reduce the labor required for maintenance.

1 is a schematic front view showing a degassing device according to an embodiment of the present invention. FIG. 2 is an exploded view showing an example of an installation mode of an impingement plate of the degassing device shown in FIG. 1 .

One embodiment of the present invention will be described in detail below. Figure 1 is a schematic front view showing a degassing device 1 according to one embodiment of the present invention. In Figure 1, the direction from top to bottom represents the vertical direction VD.

[Configuration of the degassing device]
1, the degassing device 1 can be used to degas a liquid L2 stored in a liquid tank L1. The degassing device 1 includes a discharge port 10 and an impact plate 20. The degassing device 1 may further include a pump 30, and a pipe 40 may be connected to the pump 30. In the illustrated example, the discharge port 10 is formed as an outlet of the pipe 40 on the opposite side to the pump 30.

The liquid tank L1 may be an aquarium for raising living organisms, such as fish. In this case, the liquid L2 may be, for example, seawater or fresh water. When living organisms are raised in the liquid tank L1, the carbon dioxide concentration may increase in the liquid L2 stored in the liquid tank L1 due to the metabolism of the living organisms.

The degassing device 1 according to this embodiment is used, for example, to degas carbon dioxide contained in liquid L2. However, the present invention is not limited to this, and the degassing device 1 may be used, for example, to degas dissolved gases other than carbon dioxide from liquid L2.

The outlet 10 is disposed above the liquid surface L3 of the liquid L2, and discharges the liquid L2 containing dissolved gas from above the liquid surface. In the illustrated example, the degassing device 1 has a plurality of outlets 10. The degassing device 1 has, for example, 28 outlets 10, but the number of outlets provided in the degassing device 1 may be 27 or less, or 29 or more. The greater the number of outlets 10, the higher the degassing efficiency of the degassing device 1. However, the present invention is not limited to this, and the degassing device 1 may have only one outlet 10.

The collision plate 20 is disposed between the discharge port 10 and the liquid surface L3, and causes the liquid L2 discharged from the discharge port 10 to collide with the collision plate 20, scattering the liquid L2 and causing it to fall to the liquid surface L3. In the example of FIG. 1, the degassing device 1 includes two collision plates 20. However, the present invention is not limited to this, and the degassing device 1 may include one collision plate 20 or three or more collision plates 20.

According to the above configuration, the liquid L2 discharged from the discharge port 10 is caused to collide with the collision plate 20 and splash, thereby increasing the contact area between the liquid L2 and the air, and dissolving the gas from the liquid L2. In this way, the degassing device 1 uses the collision plate 20 to degas the dissolved gas, so that no nozzle blockage occurs as in the conventional case. Therefore, according to the above configuration, a degassing device 1 can be realized that can reduce the labor required for maintenance.

As shown in FIG. 1, the distance d1 in the vertical direction VD between the discharge port 10 and the upper surface of the collision plate 20 may be equal to or greater than the distance d2 in the vertical direction VD between the lower surface of the collision plate 20 and the liquid level L3. In the above configuration, by relatively increasing the distance d1 between the discharge port 10 and the collision plate 20, the collision speed of the liquid L2 discharged from the discharge port 10 when it collides with the collision plate 20 increases, making it easier for the liquid L2 to scatter. Therefore, with the above configuration, the degassing efficiency of dissolved gas can be improved.

The ratio (C1/C2) between the carbon dioxide concentration (C1) in the liquid L2 when it reaches the liquid level L3 after colliding with the collision plate 20 and scattering, and the carbon dioxide concentration (C2) in the liquid L2 when it is discharged from the discharge port 10 may be within a predetermined range. For example, the ratio C1/C2 may be 80% or less, preferably 70% or less, and more preferably 60% or less. With the above configuration, the efficiency of degassing dissolved gas from the liquid L2 can be increased.

The collision plate 20 may be installed in a substantially horizontal direction, that is, parallel to the liquid surface L3. In such a configuration, the liquid L2 is more likely to scatter after colliding with the collision plate 20, and the contact area between the liquid L2 and the air is increased, thereby improving the efficiency of degassing the dissolved gas.

Alternatively, the collision plate 20 may be installed so as to be inclined with respect to the liquid surface L3. In such a configuration, solid impurities that accumulate on the collision plate 20 are more likely to fall to the liquid surface L3, so the amount of solid impurities that accumulate on the collision plate 20 can be reduced.

Figure 2 is an exploded view showing an example of the installation mode of the collision plate 20. As shown in Figure 2, the collision plate 20 may be a porous plate in which a plurality of through holes 21 are formed. With the above configuration, even if the liquid L2 contains solid impurities, at least a portion of the solid impurities can pass through the through holes 21, so the amount of solid impurities that accumulate on the collision plate 20 can be reduced. Therefore, the frequency of cleaning the collision plate 20 can be reduced. Examples of solid impurities include excrement and leftover food of living organisms.

The ratio of the total opening area of the multiple through holes 21 to the area of the collision plate 20 (hereinafter abbreviated as "opening area ratio") may be, for example, 0.20% or more, preferably 0.40% or more, and more preferably 0.60% or more. The higher the opening area ratio, the more the amount of solid impurities that accumulate on the collision plate 20 can be reduced.

The opening area ratio may be, for example, 5.0% or less, preferably 3.0% or less, and more preferably 1.0% or less. The lower the opening area ratio, the higher the degassing efficiency of dissolved gases can be.

The diameter of the through hole 21 may be, for example, 2.0 mm or more, preferably 4.0 mm or more, and more preferably 6.0 mm or more. The larger the diameter of the through hole 21, the more the amount of solid impurities that accumulate on the collision plate can be reduced.

The diameter of the through hole 21 may be, for example, 12 mm or less, preferably 10 mm or less, and more preferably 8.0 mm or less. The smaller the diameter of the through hole 21, the higher the degassing efficiency of the dissolved gas can be.

The collision plate 20 may be transparent or translucent. In this case, the state of contamination of the upper and lower surfaces of the collision plate 20 can be visually confirmed. The material of the collision plate 20 may be, for example, transparent polyvinyl chloride or polycarbonate.

The collision plate 20 may be attached to the stand 26 via the mesh 24. The collision plate 20 may be fixed to the mesh 24, for example, by a cable tie (not shown). When the collision plate 20 is a porous plate, it is preferable that the mesh of the mesh 24 is larger than the through-holes 21 formed in the collision plate 20. According to the above configuration, the flow of the liquid L2 passing through the through-holes 21 is less likely to stagnate, so that the decrease in the circulation efficiency of the liquid L2 due to the installation of the mesh 24 can be suppressed. Note that the installation mode of the collision plate 20 according to the present invention is not limited to the example shown in FIG. 2, and the collision plate 20 may be installed in other installation modes.

The collision plate 20 is not limited to a flat plate or a porous plate having through holes 21. Since the purpose of the collision plate 20 is to repel and scatter the liquid L2 dropped from above, it is sufficient if it can repel the liquid L2. The collision plate 20 may be, for example, an uneven plate, a corrugated plate, or a curved plate. Alternatively, the collision plate 20 may be, for example, a number of round or square bars arranged and connected in a plate shape.

As shown in FIG. 1, the pump 30 is a device that sends the liquid L2 stored in the liquid tank L1 to the discharge port 10. A known pump can be used as the pump 30. In the example of FIG. 1, the degassing device 1 includes one pump 30, but the present invention is not limited to this, and the degassing device 1 may include two or more pumps 30.

The discharge volume of the pump 30 can be changed as appropriate depending on the capacity of the liquid tank L1, etc. In addition, when living organisms are raised in the liquid tank L1, the discharge volume of the pump 30 may be changed depending on the number of living organisms raised in the liquid tank L1 and the weight of the living organisms.

For example, when the capacity of the liquid tank L1 is 100 ^m3 or more and 500 ^m3 or less, the total discharge amount per unit time of the liquid L2 discharged from the multiple discharge ports 10 may be 100 ^m3 /hour or more and 500 ^m3 /hour or less. With the above configuration, the liquid L2 in the liquid tank L1 is circulated while the dissolved gas is efficiently degassed by the collision plate 20. The discharge amount per pump 30 may be appropriately changed according to the number of pumps 30 so as to satisfy the above total discharge amount.

When carbon dioxide is degassed from the liquid L2, the amount of carbon dioxide degassed per unit time may be 50 kg/hour or more and 250 kg/hour or less. With the above configuration, the degassing device 1 can be suitably applied to, for example, fish farming. However, the present invention is not limited to this, and the degassing device 1 may be applied to purposes other than fish farming.

The pipe 40 is connected to the pump 30. A known pipe can be used as the pipe 40. The outlet 10 may be formed, for example, as an outlet of an elbow pipe located at the end of the pipe 40 opposite the pump 30, so as to face downward in the vertical direction VD. In this case, a valve (not shown) may be provided on the pump 30 side of the elbow pipe. With the above configuration, the number of outlets 10 that discharge the liquid L2 can be easily changed. Therefore, even if the total discharge amount of the liquid discharged from the multiple outlets 10 is small, the liquid pressure of the liquid L2 discharged from each outlet 10 can be increased, and the degassing efficiency of dissolved gas can be improved.

[Operation of the degassing device]
The following describes the operation of degassing dissolved gas contained in liquid using the degassing device 1. First, when the pump 30 starts to operate, the pump 30 sucks in the liquid L2 stored in the liquid tank L1 and sends it into the pipe 40. The liquid L2 sent into the pipe 40 by the pump 30 moves through the pipe 40 and is discharged from the discharge port 10.

The liquid L2 discharged from the discharge port 10 collides with the collision plate 20, scatters, and then falls to the liquid level L3. At this time, the scattered liquid L2 comes into contact with the air, and at least a portion of the dissolved gas contained in the liquid L2 is degassed. The liquid L2 that has fallen to the liquid level L3 is collected in the liquid tank L1 and is sucked back into the pump 30. In this way, the liquid L2 in the liquid tank L1 repeats the cycle of passing through the pump 30, the piping 40, and the discharge port 10, colliding with the collision plate 20, and falling to the liquid level L3. This allows the concentration of dissolved gas to be reduced while circulating the liquid L2 in the liquid tank L1.

As described above, the degassing device 1 uses the collision plate 20 to degas the dissolved gas, so there is no nozzle blockage as in the conventional case. Therefore, according to this embodiment, it is possible to realize a degassing device 1 that can reduce the labor required for maintenance.

The degassing device 1 can also be suitably applied to, for example, fish farming, where the liquid L2 may contain animal droppings and leftover food. This effect contributes to the achievement of Goal 14 of the United Nations' Sustainable Development Goals (SDGs), "Conserve and sustainably use the oceans and seas," by preventing overfishing, for example.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention.

〔Example〕
An embodiment of the present invention will be described below. Note that the degassing device 1 described in this embodiment is merely an example and does not limit the degassing device according to one aspect of the present invention.

Example 1
First, a water tank having a diameter of 15 m, a height of 2 m, and a capacity of 300 ^m3 was prepared as the liquid tank L1, and was filled with seawater as the liquid L2.

Next, four transparent polyvinyl chloride plates with a width of 600 mm, a length of 1200 mm, and a thickness of 3 mm were prepared as collision plates 20, and 144 through holes 21 with a diameter of 7.0 mm were formed in each plate so that they were evenly spaced. Specifically, eight rows of through holes 21 were formed in the width direction and 18 rows in the length direction so that the distance between the centers of adjacent through holes 21 was 60 mm in each transparent polyvinyl chloride plate. The opening area ratio was calculated to be 0.77%.

As the pump 30, a circulation pump capable of operating at a discharge rate of 300 m ³ /hour was prepared.

As shown in Figure 1, a polyvinyl chloride pipe with an inner diameter of 125 mm to 150 mm was connected to the pump 30 as the piping 40, and an elbow pipe with an inner diameter of 40 mm was connected to the opposite side of the polyvinyl chloride pipe from the pump 30. The discharge port 10 was configured to face downward in the vertical direction VD as the outlet of the elbow pipe.

The collision plate 20 was installed so that the distance d1 between the discharge port 10 and the collision plate 20 in the vertical direction VD was 1.1 m, and the distance d2 between the collision plate 20 and the liquid surface L3 in the vertical direction VD was 0.6 m. The collision plate 20 was attached to the top of the stand 26 via the mesh 24, as shown in Figure 2.

Then, while operating the pump 30, the mackerel were raised in the liquid tank L1. Note that the liquid tank L1 was provided with separate piping connected to equipment for performing each of the processes (i) solid matter removal, (ii) nitrification (ammonia removal), and (iii) oxygen dissolution, and each of the above processes (i) to (iii) was performed outside the liquid tank L1.

Immediately after the pump 30 started operation, the carbon dioxide concentration (C1) in the liquid L2 when it reached the liquid level L3 after colliding with the collision plate 20 and scattering, and the carbon dioxide concentration (C2) in the liquid L2 when it was discharged from the discharge port 10 were measured. As a result of the measurement, the ratio of C1/C2 was 53.1%, indicating good degassing efficiency.

When measured three days after starting circulation by the pump 30, the C1/C2 ratio was 42.2%, indicating that the degassing device 1 of Example 1 maintained good degassing efficiency for a long period of time.

<Comparative Example 1>
Degassing was carried out in the same manner as in Example 1, except that instead of the collision plate 20 in Example 1, a gas-liquid contact filler (manufactured by Kansai Kako Co., Ltd., product name: Bio Frontier Net) was placed in a net, which was then placed in a basket, and each basket was placed under the multiple discharge ports 10.

Immediately after starting circulation by the pump 30, the carbon dioxide concentration (C1) in the liquid L2 when it collides with the gas-liquid contact filler and is scattered, and then reaches the liquid level L3, and the carbon dioxide concentration (C2) in the liquid L2 when it is discharged from the discharge port 10 were measured. As a result of the measurement, the ratio of C1/C2 was 46.0%, indicating good degassing efficiency.

However, three days after starting circulation by pump 30, part of the gas-liquid contact filler became clogged with mackerel feces and residual food. For this reason, in Comparative Example 2, it was confirmed that frequent maintenance of the gas-liquid contact filler was necessary to prevent a decrease in degassing efficiency.

〔summary〕
[1]
a discharge port that is disposed above a liquid surface of the liquid stored in the liquid tank and that discharges the liquid containing dissolved gas from above the liquid surface;
a collision plate disposed between the discharge port and the liquid surface, which causes the liquid discharged from the discharge port to collide with the collision plate, causing the liquid to scatter and then drop onto the liquid surface;
A degassing device comprising:

[2]
The degassing apparatus according to [1], wherein the collision plate is a perforated plate having a plurality of through holes formed therein.

[3]
The degassing device according to [1] or [2], wherein a vertical distance between the discharge port and the collision plate is equal to or greater than a vertical distance between the collision plate and the liquid surface.

[4]
Equipped with a plurality of discharge ports,
A degassing apparatus as described in any one of [1] to [3], wherein when the capacity of the liquid tank is 100 ^m3 or more and ⁵⁰⁰ m3 or less, a total discharge amount of the liquid discharged from the multiple discharge outlets per unit time is 100 ^m3 /hour or more and 500 ^m3 /hour or less.

[5]
the dissolved gas is carbon dioxide;
The degassing apparatus according to any one of [1] to [4], wherein the amount of carbon dioxide degassed from the liquid per unit time is 50 kg/hour or more and 250 kg/hour or less.

REFERENCE SIGNS LIST 1 Degassing device 10 Discharge port 20 Collision plate 24 Mesh 26 Stand 30 Pump 40 Pipe d1 Distance between discharge port and collision plate in the vertical direction d2 Distance between collision plate and liquid surface in the vertical direction L1 Liquid tank L2 Liquid L3 Liquid surface

Claims (5)

a discharge port that is disposed above a liquid surface of the liquid stored in the liquid tank and that discharges the liquid containing dissolved gas from above the liquid surface;
a collision plate disposed between the discharge port and the liquid surface, which causes the liquid discharged from the discharge port to collide with the collision plate, causing the liquid to scatter and then drop onto the liquid surface;
A degassing device comprising: The degassing device according to claim 1, wherein the collision plate is a perforated plate having a plurality of through holes formed therein. The degassing device according to claim 1 or 2, wherein the vertical distance between the discharge port and the collision plate is equal to or greater than the vertical distance between the collision plate and the liquid surface. Equipped with a plurality of discharge ports,
3. The degassing apparatus according to claim 1 or 2, wherein when the capacity of the liquid tank is 100 ^m3 or more and 500 ^m3 or less, a total discharge amount of the liquid discharged from the multiple discharge ports per unit time is 100 ^m3 /hour or more and 500 ^m3 /hour or less. the dissolved gas is carbon dioxide;
5. The degassing apparatus according to claim 4, wherein the amount of carbon dioxide degassed from the liquid per unit time is 50 kg/hour or more and 250 kg/hour or less.

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