JP7808017B2 - Degassing device - Google Patents

Description

The present invention relates to a degassing device.

A variety of techniques have been known for removing dissolved gases from liquids. For example, Patent Documents 1 and 2 disclose a technique for removing carbon dioxide from water to be treated by spraying the water with dissolved carbon dioxide from a nozzle. Furthermore, Patent Documents 3 and 4 disclose a technique for removing exhaust gases from fish and shellfish contained in water for rearing fish and shellfish by blowing air or other gases into the water.

JP 2012-120993 A Japanese Unexamined Patent Publication No. 7-178387 Japanese Patent Application Publication No. 5-3735 Patent No. 6858996

However, the technology of spraying a liquid containing dissolved gas from a nozzle has the problem of nozzle clogging, which requires a lot of maintenance effort. Furthermore, the technology of blowing air or other gas into a liquid containing dissolved gas has the problem of dirt easily accumulating in the air blowing section of the aeration tube, which requires a lot of maintenance effort. One aspect of the present invention aims to realize a degassing device that reduces the amount of maintenance effort required.

To solve the above problem, a degassing device according to one aspect of the present invention comprises an outlet disposed above the liquid surface of a liquid stored in a liquid tank, which discharges the liquid containing dissolved gas from above the liquid surface, and an impact plate disposed between the outlet and the liquid surface, which impacts the liquid discharged from the outlet to cause the liquid to splash and then fall onto the liquid surface.

One aspect of the present invention makes it possible to realize a degassing device that reduces 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 degassing device]
1, a degassing apparatus 1 can be used to degas a liquid L2 stored in a liquid tank L1. The degassing apparatus 1 includes a discharge port 10 and an impingement plate 20. The degassing apparatus 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 from 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 freshwater. 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 also be used, for example, to degas dissolved gases other than carbon dioxide from liquid L2.

The outlets 10 are positioned above the liquid surface L3 of the liquid L2 and eject the liquid L2 containing dissolved gas from above the liquid surface. In the illustrated example, the degassing device 1 has multiple outlets 10. The degassing device 1 has, for example, 28 outlets 10, but the number of outlets provided by 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 positioned between the discharge port 10 and the liquid level 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 level L3. In the example shown in Figure 1, the degassing device 1 is equipped with two collision plates 20. However, the present invention is not limited to this, and the degassing device 1 may be equipped with one collision plate 20 or three or more collision plates 20.

With the above configuration, the liquid L2 ejected from the outlet 10 collides with the collision plate 20, causing it to splash, thereby increasing the contact area between the liquid L2 and the air and degassing the dissolved gas from the liquid L2. In this way, the degassing device 1 degasses the dissolved gas using the collision plate 20, so nozzle blockages, as with conventional devices, do not occur. Therefore, with the above configuration, a degassing device 1 can be realized that reduces the effort 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) of the carbon dioxide concentration (C1) in the liquid L2 when it reaches the liquid surface L3 after colliding with the collision plate 20 and scattering, to the carbon dioxide concentration (C2) in the liquid L2 when it is ejected from the ejection 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. This configuration can increase the efficiency of degassing dissolved gas from the liquid L2.

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

Alternatively, the collision plate 20 may be installed so that it is inclined relative to the liquid surface L3. In this configuration, solid impurities that accumulate on the collision plate 20 are more likely to fall to the liquid surface L3, thereby reducing the amount of solid impurities that accumulate on the collision plate 20.

Figure 2 is an exploded view showing an example of an installation mode of the collision plate 20. As shown in Figure 2, the collision plate 20 may be a perforated plate with multiple through-holes 21 formed therein. With this configuration, even if the liquid L2 contains solid impurities, at least some of the solid impurities can pass through the through-holes 21, thereby reducing the amount of solid impurities that accumulate on the collision plate 20. This reduces the frequency of cleaning the collision plate 20. Examples of solid impurities include animal droppings and leftover food.

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 effectively 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.

The diameter of the through-holes 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-holes 21, the more effectively the amount of solid impurities that accumulate on the collision plate can be reduced.

The diameter of the through-holes 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-holes 21, the more efficient the degassing of dissolved gases can be.

The collision plate 20 may be transparent or translucent. In this case, the degree of contamination on 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 a mesh 24. The collision plate 20 may be fixed to the mesh 24, for example, with a cable tie (not shown). If the collision plate 20 is a perforated plate, the mesh 24 preferably has a larger opening than the through-holes 21 formed in the collision plate 20. With the above configuration, the flow of the liquid L2 that passes through the through-holes 21 is less likely to stagnate, thereby preventing a decrease in the circulation efficiency of the liquid L2 due to the installation of the mesh 24. 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 ways.

Note that the collision plate 20 is not limited to a flat plate or a perforated plate with through holes 21. Since the purpose of the collision plate 20 is to repel and scatter the liquid L2 dropped from above, it need only be something that 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 rods arranged and connected together 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 rate of the pump 30 can be changed as appropriate depending on the capacity of the liquid tank L1, etc. Furthermore, if living organisms are being raised in the liquid tank L1, the discharge rate of the pump 30 may be changed depending on the number and weight of the living organisms being raised in the liquid tank L1.

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 changed appropriately depending on the number of pumps 30 so as to satisfy the above total discharge amount.

Furthermore, when degassing carbon dioxide from 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 also be applied to applications 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 the outlet of an elbow pipe located at the end of the pipe 40 opposite the pump 30, facing 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 volume of liquid discharged from 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 when degassing dissolved gas contained in a liquid using the degassing device 1. First, when the pump 30 starts operating, 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.

Liquid L2 ejected from outlet 10 collides with collision plate 20, splashes, and then falls to liquid level L3. At this time, the splashed liquid L2 comes into contact with air, causing at least some of the dissolved gas contained in liquid L2 to be degassed. Liquid L2 that has fallen to liquid level L3 is collected in liquid tank L1 and then sucked back into pump 30. In this way, liquid L2 in liquid tank L1 passes through pump 30, piping 40, and outlet 10, collides with collision plate 20, and falls to liquid level L3, repeating this cycle. This allows the concentration of dissolved gas to be reduced while circulating liquid L2 in liquid tank L1.

As described above, the degassing device 1 uses the collision plate 20 to degas dissolved gases, so nozzle blockages, as in conventional devices, do not occur. Therefore, this embodiment makes it possible to realize a degassing device 1 that reduces the labor required for maintenance.

The degassing device 1 can also be suitably applied to, for example, fish farming, where animal droppings and leftover food may be generated in the liquid L2. This effect can also contribute to achieving Goal 14 of the United Nations' Sustainable Development Goals (SDGs), "Conserve and sustainably use the water below sea level," by preventing overfishing, for example.

The present invention is not limited to the above-described embodiments, 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 m ³ was prepared as the liquid tank L1, and was filled with seawater as the liquid L2.

Next, four transparent vinyl chloride plates measuring 600 mm wide, 1200 mm long, and 3 mm thick were prepared as collision plates 20, and 144 evenly spaced through holes 21 with a diameter of 7.0 mm were formed in each plate. Specifically, eight rows of through holes 21 were formed in the width direction and 18 rows in the length direction in each transparent vinyl chloride plate, with the distance between the centers of adjacent through holes 21 being 60 mm. 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.

The piping 40 was a vinyl chloride pipe with an inner diameter of 125 mm to 150 mm connected to the pump 30 as shown in Figure 1, and an elbow pipe with an inner diameter of 40 mm was connected to the opposite side of the vinyl 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. As shown in Figure 2, the collision plate 20 was attached to a stand 26 via a mesh 24.

Then, while operating the pump 30, mackerel were raised in the liquid tank L1. Note that the liquid tank L1 was equipped with separate piping connected to equipment for the following processes: (i) solid matter removal, (ii) nitrification (ammonia removal), and (iii) oxygen dissolution; the above processes (i) to (iii) were carried out 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 surface 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. The measurement results showed that the C1/C2 ratio was 53.1%, indicating good degassing efficiency.

Furthermore, when measured three days after starting circulation using the pump 30, the C1/C2 ratio was 42.2%, demonstrating 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: Biofrontier Net) was placed in a net, which was then placed in a basket and placed under each of the multiple discharge ports 10.

Immediately after circulation by pump 30 began, the carbon dioxide concentration (C1) in liquid L2 was measured when it reached the liquid level L3 after colliding with the gas-liquid contact filler and scattering, and the carbon dioxide concentration (C2) in liquid L2 when it was discharged from discharge port 10. The measurement results showed that the C1/C2 ratio was 46.0%, indicating good degassing efficiency.

However, three days after starting circulation using the pump 30, part of the gas-liquid contact filler became clogged with mackerel droppings and leftover food. Therefore, in Comparative Example 2, it was confirmed that frequent maintenance of the gas-liquid contact filler was necessary to prevent a decline in degassing efficiency.

〔summary〕
[1]
a discharge port disposed above the liquid surface of the liquid stored in the liquid tank, for discharging 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 device 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 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.

[4]
It has a plurality of outlets,
A degassing apparatus according to any one of [1] to [3], wherein when the capacity of the liquid tank is 100 ^m3 or more and 500 ^m3 or less, the total discharge amount of the liquid discharged from the plurality of discharge ports 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.

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 disposed above the liquid surface of a liquid stored in a liquid tank for raising fish , the discharge port discharging the liquid containing dissolved gas and excrement or residual food of the fish 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;
Equipped with
the collision plate is a perforated plate having a plurality of through holes formed therein;
A degassing device , wherein the ratio of the total opening area of the plurality of through holes to the area of the collision plate is 0.20% or more and 5.0% or less, and the diameter of the plurality of through holes is 2.0 mm or more and 12.0 mm or less . The collision plate is attached to a base via a mesh,
The degassing device according to claim 1 , wherein the mesh openings are larger than the plurality of through holes. A degassing device as described in 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. It has a plurality of outlets,
The degassing apparatus according to claim 1 or 2, wherein when the capacity of the liquid tank is 100 m ³ or more and 500 ^m 3 or less, the total discharge amount of the liquid discharged from the plurality of discharge ports per unit time is 100 m ³ /hour or more and 500 m ³ /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.