JP2021000052A - Algae-culturing tank system and algae-culturing method - Google Patents

Abstract

To preferably culture algae in a water tank in which damage such as shear to algae in the tank is suppressed while stirring water in the water tank.SOLUTION: An algae-culturing tank system has: a circulation pipe 5 which sucks water and algae to be cultured in a tank 2 from a suction port 4 at an upper part of the tank 2 by a pump 6, and supplies water and algae into the tank 2 from a supply port 3 at a lower part of the tank 2; an air supply pump 7 which supplies air into the tank 2; and baffle plates 11 and 14 which are provided in the tank 2, and generate a turbulent flow against a swirling flow generated in the tank 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to an algae culture tank system and an algae culture method.

Conventionally, there is a technique disclosed in Patent Document 1 as a technique for culturing algae. In the technique described in Patent Document 1, seawater and nori seaweed can be introduced into the tank, and the seaweed algae can maintain the activity at the temperature of the seawater in the tank while stirring the mixture of seawater and seaweed. It is characterized by supplying cold air that can be adjusted to temperature into seawater to disperse the air. Further, as a stirring device for stirring seawater and seaweed raw algae, a stirring shaft is attached in the vertical direction to a rotating shaft driven by a motor, and the stirring shaft has a required length at three locations at equal intervals in the longitudinal direction. The one provided with the stirring blade of the above is disclosed. Each stirring blade is inclined so that the tip side is slightly lower than the horizontal direction, and is inclined in the direction of scooping up seawater in the rotation direction, which is a so-called stirring propeller structure.

Japanese Unexamined Patent Publication No. 2007-129972

However, in the technique disclosed in Patent Document 1, since the seawater in the storage tank is agitated by rotating the blades of the agitating means, the algae may be sheared and the algae may be damaged. .. Some algae may die if sheared too much.

The present invention has been made in view of this point, and when culturing algae in the aquarium tank, the algae are preferably algae by suppressing damage such as shearing to the algae in the tank while stirring the water in the aquarium tank. Is intended for culturing.

In order to achieve the above object, the present invention is an algae culture tank system for culturing algae in a tank having a cylindrical internal shape, in which water in the tank is sucked from an upper suction port in the tank to obtain the above. Air is supplied to the circulation pipe connected so as to supply water into the tank from the lower supply port in the tank, the pump provided in the circulation pipe, and the water circulating in the suction port-supply port-tank. It has an air supply means for supplying air and a resistor provided in the tank that generates turbulent flow against the water flow generated in the tank, and the supply port is provided along a tangential direction in the tank. It is characterized in that water is supplied into the tank from the above.

According to the present invention, water is supplied into the tank from the lower supply port in the tank along the tangential direction in the tank, and water in the tank is sucked from the upper suction port in the tank. Therefore, a swirling flow that gradually moves upward is generated in the tank. On the other hand, since the tank is provided with a resistor that generates turbulence against the water flow generated in the tank, turbulence is generated together with the swirling flow, and the water in the tank is the algae to be cultured. Stir with and disperse in the tank. Further, the air (oxygen) supplied by the air supply means for supplying air to the water circulating in the suction port-supply port-tank is also agitated and dispersed in the tank in the same manner. Therefore, since air (oxygen) is continuously supplied to the algae in the tank, the algae can be cultivated. Further, in the present invention, since the conventional diffusion propeller that rotates in the tank is not used, the algae are not damaged. Therefore, it is possible to preferably culture algae.

The air supply means may be an air supply mechanism that directly supplies air into the tank from below in the tank. A so-called conventionally known aeration mechanism or bubbling mechanism can be adopted as it is.

Further, the air supply means may use an air supply mechanism for supplying air into the circulation pipe. If air is mixed into the circulation pipe, the air required for algae can be mixed with water with less energy than the aeration mechanism and bubbling mechanism described above.

Furthermore, the air supply means may be an ejector provided in the circulation pipe. Even when the ejector is adopted in this way, the air required for algae can be mixed with water with less energy than the aeration mechanism and the bubbling mechanism described above. Examples of the ejector that can be adopted in the present invention include a water ejector that uses water as a driving fluid. That is, a nozzle is provided in a body having a diffuser in the discharge direction, and water from a pump is pumped toward the nozzle as a driving fluid to take in air from an air suction port provided in the body and use this as water. An ejector having a configuration in which the mixture is mixed with and supplied from the diffuser into the circulation pipe can be adopted.

As the resistor, an obstacle plate provided on the inner wall of the tank and projecting inside the tank can be exemplified. Of course, the plate is not limited to the baffle plate, and any protrusion or projecting piece may be used as long as it projects into the tank and generates turbulent flow against the water flow generated in the tank. Further, these may be fixed in the tank by welding or the like, but may be formed by deforming the tank inward. The number and arrangement of resistors can be appropriately adopted according to the properties of the algae cultivated in the tank.

The resistor may be provided between the supply port and the suction port in the height direction of the tank. By arranging in this way, a swirling flow can be efficiently generated by the water supplied from the supply port.

It may be configured to have a heat exchanger that exchanges heat between the water flowing through the circulation pipe and an external heat medium. When culturing algae in a tank, there is an optimum temperature. In addition, the temperature of the water in the tank may fluctuate depending on the progress of culture. Therefore, suitable culture can be realized by always setting the temperature of the water supplied to the tank by the heat exchanger to an appropriate temperature.

According to another viewpoint, the present invention is an algae culturing method for culturing algae in a tank, in which water in the tank is sucked by a pump from an upper suction port in the tank to lower the tank. Water is returned to the tank from the supply port of the above, air is mixed in the water circulating through the suction port-supply port-tank, and when the water is returned from the supply port, a swirling flow is made into the tank. It is characterized in that the supply direction is set so as to generate the above-mentioned, and the turbulent flow is generated against the swirling flow by the resistor arranged in the tank.

In such a case, the flow rate of water sucked from the tank and returned to the tank may be changed according to the state of the algae in the tank, for example, the growth state and the ups and downs state. This makes it possible to prevent the uneven distribution of algae in the tank and effectively realize the culture of algae.

Furthermore, the supply angle in the height direction of the water supplied from the supply port into the tank may be changed depending on the state of the algae in the tank. Also by such a method, it is possible to prevent uneven distribution of algae in the tank and effectively realize the culture of algae. Further, it is more effective when used in combination with the above-mentioned change in water flow rate.

According to the present invention, when culturing algae in the aquarium, it is possible to preferably cultivate the algae while stirring the water in the aquarium and suppressing damage to the algae in the aquarium.

It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on 1st Embodiment. It is a plane explanatory view of the algae culture tank system of FIG. It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on the 2nd Embodiment. It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on 3rd Embodiment. It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on 4th Embodiment. It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on 5th Embodiment. It is a plane explanatory view which shows typically the structure of the algae culture tank system which concerns on 6th Embodiment. It is a front explanatory view which shows typically the structure of the algae culture tank system which concerns on 7th Embodiment.

Hereinafter, the algae culture tank system according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted.

FIG. 1 shows an outline of the configuration of the algae culture tank system 1 according to the first embodiment, and the tank 2 having a cylindrical inside is for storing water for culturing algae. A supply port 3 is provided below the tank 2, and a suction port 4 is provided above the tank 2, more specifically, at a position lower than the water surface of the stored water.

A circulation pipe 5 is connected between the supply port 3 and the suction port 4 on the outside of the tank 2. The circulation pipe 5 has a supply pipe 5a connected to the supply port 3 and a suction pipe 5b connected to the suction port 4. A pump 6 is provided in the circulation pipe 5. In this embodiment, the pump 6 is provided in the supply pipe 5a. With such a configuration, the water in the tank 2 circulates through the suction port 4-circulation pipe 5-supply port 3-tank 2.

In this algae culture tank system 1, the algae to be cultivated are cultivated in the tank 2, but the suction port 4 itself is not particularly provided with a filter or the like for collecting the algae. Therefore, the algae in the tank 2 circulate in the suction port 4-circulation pipe 5-supply port 3-tank 2 together with the circulating water. Therefore, in the present embodiment, the volume of water within a certain space volume is changed by reciprocating motion or rotational motion to apply energy so that the algae are not sheared or crushed when passing through the pump 6. , A positive displacement pump is adopted.

At the bottom of the tank 2, an air introduction port 8 for supplying air from an air supply pump 7 as an air supply means is provided. Further, a discharge port 9 for discharging the air in the tank 2 is provided in the upper part of the tank 2.

As shown in FIG. 2, the supply pipe 5a connected to the supply port 3 of the tank 2 is connected in the tangential direction in the tank 2. As a result, the water supplied from the supply port 3 into the tank 2 generates a swirling flow in the tank 2. In the present embodiment, the suction pipe 5b connected to the suction port 4 is also connected in the tangential direction in the tank 2. This makes it possible to more effectively generate a swirling flow in the tank 2.

Further, as shown in FIGS. 1 and 2, in the present embodiment, as a resistor for generating turbulent flow against the swirling flow described above, baffle plates 11 to 14 are provided in the vertical direction of the inner wall of the tank 2. It is provided. The baffle plates 11 to 14 have a shape protruding toward the center of the tank 2, and are provided at intervals of 90 degrees in a plan view. Further, the upper end portions of the baffle plates 11 to 14 are set to be located below the suction port 4.

The algae culture tank system 1 according to the first embodiment has the above configuration, and the algae to be cultivated are mixed in the water in the tank 2. Then, when the pump 6 is operated, the water in the tank 2 is sucked together with the algae from the suction port 4, passes through the circulation pipe 5, and is returned to the tank 2 from the supply port 3 of the tank 2. At this time, since the supply pipe 5a connected to the supply port 3 is along the tangential direction in the tank 2 as shown in FIG. 2, a swirling flow is generated in the tank 2, and the swirling flow is generated. It will gradually rise.

However, since the obstruction plates 11 to 14 which are resistors for generating turbulent flow against the swirling flow are provided in the tank 2, turbulent flow is generated together with the swirling flow. Therefore, the water and algae in the tank 2 are agitated and dispersed in the tank 2. Since the air from the air supply pump 7 is supplied to the bottom of the tank 2, the air becomes bubbles and is mixed into the swirling flow and the turbulent flow, and is agitated in the same manner as algae into the tank 2. scatter. Therefore, air (oxygen) can be effectively and continuously supplied to the algae in the tank 2, and the algae can be suitably cultured.

Further, in the algae culture tank system 1 according to the embodiment, since the algae are not stirred by the conventional stirring propeller, the algae are not sheared or damaged when being stirred in the tank 2. Further, as for the pump 6, since a positive displacement pump is used, the algae are not crushed or damaged in this respect as well.

Furthermore, the energy of the pump 6 can be reduced as compared with the case of stirring by rotating the stirring propeller in the tank as in the conventional case. And only the baffle plates 11 to 14 are provided in the tank 2, and the structure is not particularly complicated. Therefore, daily cleaning and maintenance of the tank is easy. Moreover, since general pipes 5 and pumps 6 can be used, they can be replaced even if they deteriorate over time, for example. Therefore, the algae culture tank system 1 according to the embodiment can keep the life cycle cost lower than the conventional one.

In the above embodiment, the baffle plates 11 to 14 are all of the same shape and the same height and the same height. However, for example, the heights of the baffle plates are in this order from the baffle plate 11 to the baffle plates 12, 13 and 14. It may be configured to be high. As a result, the resistance to the water flow gradually increases, and it is possible to prevent excessive turbulence. Further, by enlarging the baffle plate 12 close to the suction port 4, the amount of algae sucked from the suction port 4 can be reduced. From this point of view, the amount of algae sucked from the suction port 4 can be similarly reduced by providing the baffle plate 12 so as to be close to the suction port 4.

By the way, focusing on the functional aspect of the tank for culturing algae, the circulation flow rate of the pump 6 is adjusted in terms of the oxygen transfer capacity coefficient (kLa), that is, the agitation property for the purpose of supplying oxygen to organisms into the tank. Therefore, if the swirling flow velocity equivalent to that of the stirring propeller is exhibited, the equivalent stirring performance can be easily realized. In such a case, for example, if the rotation speed of the pump 6 is controlled by using an inverter, the power required for water circulation can be significantly reduced. Therefore, it is clear that the required power can be significantly reduced by circulating a part of the water in the tank 2 as in the embodiment, rather than stirring all the water in the tank 2 by the stirring propeller.

By the way, when culturing algae in a tank, there is an optimum temperature for culturing algae. In general, the temperature of water in the tank may rise depending on the progress of culture. Therefore, it has been devised to keep the temperature of the water in the tank constant. Conventionally, in general microbial culture, a method of heating and cooling by forming a tank into a double structure and flowing hot water or cold water through the gap between the double walls is often adopted. However, such a method complicates the structure of the tank.

The second embodiment described below solves such a problem. FIG. 3 shows an outline of the configuration of the algae culture tank system 1 according to the second embodiment. The algae culture tank system 1 according to the second embodiment is the water flowing through the circulation pipe 5 in the circulation pipe 5 with respect to the algae culture tank system 1 according to the first embodiment shown in FIG. A heat exchanger 21 for exchanging heat between the heat exchanger and the heat medium supplied from the outside is provided. That is, the heat exchanger 21 exchanges heat between a heat medium (for example, cold water or hot water) supplied from the outside through the pipe 22 and water flowing through the circulation pipe 5.

As described above, since the water flowing through the circulation pipe 5 also contains algae in the tank 2, the structure that does not damage the algae when passing through the heat exchanger 21, that is, the internal flow path is complicated. Not a heat exchanger is preferred. For example, spiral heat exchangers and shell-and-tube heat exchangers are suitable. Further, in the algae culture tank system 1 according to the second embodiment, the heat insulating material 23 is provided on the outside of the tank 2. As the heat insulating material, a general commercially available material can be used.

According to the algae culture tank system 1 according to the second embodiment having the above configuration, it is easy to maintain the water in the tank 2 at a predetermined temperature by heat exchange by the heat exchanger 21, and further heat insulation. Since the outer surface of the tank 2 is covered with the material 23, heat conduction with the outside is also suppressed, and it is easy to maintain a predetermined temperature at this point as well. Moreover, the running cost required for these can be kept low. Moreover, the structure of the tank 2 itself remains simple, and the heat exchanger 21 only needs to be installed in the circulation pipe 5, so that the construction is easy. When the structure of the tank becomes complicated, the algae are clogged and the circulation is obstructed or cleaning becomes difficult. However, according to this configuration, the algae can be grown suitably.

Next, a third embodiment will be described. FIG. 4 shows an outline of the configuration of the algae culture tank system 1 according to the third embodiment, and in the third embodiment, it was adopted in the first embodiment shown in FIG. Instead of supplying air into the tank 2 from the bottom of the tank 2 as an air supply means by an air supply pump 7, an air supply pipe 31 is connected to a suction pipe 5b in the circulation pipe 5, and the pipe 31 is connected. Is provided with an air supply pump 32.

According to the algae culture tank system 1 according to the third embodiment having such a configuration, the power required for the air supply pump 32 can be suppressed as compared with the above-mentioned first embodiment. That is, when air is supplied from the bottom of the tank 2 into the tank by an air supply pump 7 such as a compressor, it is necessary to supply air against the water pressure as the height of the tank, that is, the depth of the water becomes deeper. , The required power increases. On the other hand, as shown in FIG. 4, if air is supplied to the suction pipe 5b located at a height close to the water surface of the tank 2, the required power can be reduced. Therefore, the algae culture tank system 1 according to the third embodiment can reduce the running cost as compared with the algae culture tank system 1 according to the first embodiment, and the rating of the air supply pump 32 is the first. It can be smaller than the algae culture tank system 1 according to the embodiment of. In this case, the amount of air supplied by the air supply pump 32 and the amount of water circulated by the pump 6 can be adjusted to be appropriate. That is, the air supply and the water circulation can be controlled under different conditions. For example, the air supply amount is adjusted according to the degree of algae growth, and the amount of water required to circulate the algae in the tank is supplied. It is possible to perform control such as

Next, the fourth embodiment will be described with reference to FIG. The algae culture tank system 1 according to the fourth embodiment employs an ejector 41 as an air supply means. That is, the supply pipe 5a in the circulation pipe 5 has a configuration in which the ejector 41 is provided on the downstream side of the pump 6.

According to the algae culture tank system 1 according to the fourth embodiment having such a configuration, since the ejector 41 is adopted as the air supply means, it is possible to further reduce the power required for supplying air. Is. That is, since the ejector 41 creates a contraction in the supply pipe 5a, the outside air can be pushed into the water in the supply pipe 5a without the need for power, so that the ejector 41 circulates without the need for a compressor or an air pump. Air can be supplied to the water in the tank 2.

That is, as described above, when a water ejector whose driving fluid is water is used as the ejector 41, water from the pump 6 is pumped toward a nozzle (not shown) in the body and passed through the nozzle. When the air is discharged from the diffuser 41a, air can be taken in from the air suction port 41b and mixed when the air is discharged from the diffuser 41a to the supply pipe 5a. Therefore, it is possible to supply air to the water in the circulating tank 2 without the need for a special compressor or air pump. When the ejector 41 is adopted, if algae enter the ejector 41, the algae may be clogged or the algae itself may be damaged. Therefore, it is desirable to suppress the algae flowing in from the suction port 4.

Next, a fifth embodiment will be described. FIG. 6 shows an outline of the configuration of the algae culture tank system 1 according to the fifth embodiment, and in the third embodiment, it was adopted in the first embodiment shown in FIG. As shown in FIG. 6, the lengths of the baffle plates 11 to 14 in the height direction are set to be located between the supply port 3 and the suction port 4. That is, the baffle plates 11 to 14 as resistors are provided between the supply port 3 and the suction port 4. In other words, the supply port 3 is provided with a region in the horizontal direction that does not form a baffle plate.

According to the algae culture tank system 1 according to the fifth embodiment having such a configuration, the water supplied from the supply port 3 along the tangential direction in the tank 2 is located at the lower part of the baffle plates 11-14. Since there is no collision, the water supplied into the tank 2 initially flows smoothly along the inner circumference of the tank 2, so that a swirling flow is likely to occur, and even if the water is sucked from the suction port 4, it interferes. The plates 11-14 do not block the water flow. Therefore, a swirling flow can be efficiently generated in the tank 2. Further, since water does not hit only one of the baffle plates 11 to 14, the baffle plates 11 to 14 can be formed evenly.

Further, from the viewpoint that the flow of water supplied from the supply port 3 is not obstructed at the initial stage of supply, as in the sixth embodiment shown in FIG. 7, the water flow first collides with the obstacle. The board may not be provided. That is, the example shown in FIG. 7 has a configuration in which the obstruction plate 11 is removed from the algae culture tank system 1 according to the first embodiment shown in FIG. As described above, the baffle plates as resistors do not have to be evenly arranged in the tank 2 at equal intervals, and may be any one that generates turbulent flow against the swirling flow.

By the way, the algae in the tank are not always evenly dispersed in the tank 2 while stirring, for example, when they sink to the bottom in the tank 2 or float near the water surface in the tank 2. There is. For example, in the early stage of culture, it tends to sink to the bottom in the tank 2, and in the final stage of culture, it may float near the water surface in the tank 2. In such a case, the rotation speed of the pump 6 may be changed accordingly to change the amount of circulating water. That is, if the rotation speed of the pump is controlled and the flow rate is adjusted according to the dispersed state of these algae, it is possible to appropriately respond according to the ups and downs of the algae, the agitation of the algae is improved, and the culture is performed. It is possible to reduce the required power while maintaining an appropriate stirring property at the final stage.

Further, instead of or in conjunction with such flow rate adjustment, the supply angle of the water supplied from the supply port 3 may be changed in the vertical direction. FIG. 8 shows an outline of the configuration of the algae culture tank system 1 according to the seventh embodiment, in which the vertical supply angle of the water supplied from the supply port 3 can be changed.

The algae culture tank system 1 according to the seventh embodiment can switch the supply port 3 in the algae culture tank system 1 according to the first embodiment shown in FIG. 1 as shown in FIG. It is composed of three supply ports 3a, 3b, and 3c. That is, in the seventh embodiment, the supply pipe 5a is branched into three on the downstream side of the pump 6, the branched pipes are arranged in the vertical direction in the tank 2, and each branched pipe and the tank 2 are arranged. The supply ports formed in the connecting portion are the upward supply port 3a, the horizontal supply port 3b, and the downward supply port 3c, respectively.

Corresponding valves V1, V2, and V3 are provided in each pipe branched from the supply pipe 5a, and water from the supply pipe 5a is upwardly supplied to the supply port 3a and the horizontal supply port by switching the valves V1 to V3. By switching to 3b and the downward supply port 3c, it is possible to supply in each of the upward, horizontal, and downward directions from below in the tank 2.

Further, as in the algae culture tank system 1 according to the seventh embodiment, the height positions of the lower ends of the baffle plates 11 to 14 may be changed.

According to the algae culture tank system 1 according to the seventh embodiment having the above configuration, when the algae are sunk to the bottom in the tank 2 as in the initial stage of culture, the tank is connected from the downward supply port 3c. Water is supplied downward in 2 and, for example, when algae are floating near the water surface in tank 2 as in the final stage of culture, water is supplied upward in tank 2 from the upward supply port 3a, and other In the case of, the water can be horizontally supplied into the tank 2 from the horizontal supply port 3b. Therefore, it is possible to form an appropriate water flow according to the ups and downs of algae in the tank 2.

In such a case, for example, the power of the pump 6 may be suppressed when the algae are floating near the water surface in the tank 2, and the power of the pump 6 may be increased when the algae are submerged in the bottom of the tank 2. By controlling in this way, it is possible to minimize the power of the pump 6 required in each case and reduce the energy required to operate the system.

The algae culture tank system 1 according to each of the above embodiments is suitable for culturing algae, which requires less air (oxygen) than microorganisms, but the present invention is particularly as described above. It is useful for culturing algae cultivated in a closed tank 2 as a whole except for the discharge port 9. Among them, it is suitable for culturing algae that do not perform photosynthesis, such as Aurantiochytrium.
The inner shape of the tank is expressed as a substantially cylindrical shape, but includes an elliptical shape. It also includes a cylindrical shape that has been deformed to maintain a smooth inner surface. For example, those having irregularities on the inside are also referred to as substantially cylindrical in the present specification.

Further, the tank used in the algae culture tank system according to the present embodiment is designed so that the inside of the tank is stirred by a water stream regardless of the stirring propeller structure. For example, mixing of chemicals, foodstuffs and equipment It may be applied to various uses such as cleaning of.

The present invention is useful for culturing algae.

1 Algae culture tank system 2 Tank 3 Supply port 4 Suction port 5 Circulation pipe 5a Supply pipe 5b Suction pipe 6 Pump 7, 32 Air supply pump 8 Air inlet 9 Discharge port 11-14 Baffle plate 21 Heat exchanger 22, 31 piping 23 Insulation 41 Ejector

Claims (10)

An algae culture tank system that cultivates algae in a tank with a cylindrical inside.
A circulation pipe connected so as to suck water in the tank from the upper suction port in the tank and supply water into the tank from the lower supply port in the tank.
The pump provided in the circulation pipe and
An air supply means for supplying air to the water circulating in the suction port-supply port-tank, and
It has a resistor provided in the tank and generates turbulent flow against the water flow generated in the tank.
An algae culture tank system, characterized in that water is supplied into the tank from the supply port along a tangential direction in the tank. The algae culture tank system according to claim 1, wherein the air supply means is an air supply mechanism that directly supplies air into the tank from below in the tank. The algae culture tank system according to claim 1, wherein the air supply means is an air supply mechanism that supplies air into the circulation pipe. The algae culture tank system according to claim 1, wherein the air supply means is an ejector provided in the circulation pipe. The algae culture tank system according to any one of claims 1 to 4, wherein the resistor is a baffle plate provided on the inner wall of the tank and projecting inside the tank. The algae culture tank according to any one of claims 1 to 5, wherein the resistor is provided between the supply port and the suction port in the height direction of the tank. system. The algae culture tank system according to any one of claims 1 to 6, further comprising a heat exchanger that exchanges heat between the water flowing through the circulation pipe and an external heat medium. This is an algae culture method for culturing algae in a tank.
The water in the tank is sucked by a pump from the upper suction port in the tank, and the water is returned to the tank from the lower supply port in the tank.
Air is mixed into the water circulating in the suction port-supply port-tank.
When returning water from the supply port, the supply direction is set so as to generate a swirling flow in the tank, and a resistor arranged in the tank generates a turbulent flow against the swirling flow. A method for culturing algae, which is characterized by the above. The algae culturing method according to claim 8, wherein the flow rate of water sucked from the tank and returned to the tank is changed depending on the state of the algae in the tank. The algae according to any one of claims 8 or 9, wherein the supply angle in the height direction of the water supplied from the supply port into the tank is changed depending on the state of the algae in the tank. Culture method.

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