Culture system

Abstract

To provide a culture system that can prevent a decrease in culture efficiency.SOLUTION: A culture system 1 includes: a culture tank 24a that houses a culture solution C for culturing photosynthetic microorganisms P; a discharge pipe 51 extending in a Z-axis direction and disposed to be vertically movable in the Z-axis direction, where the discharge pipe 51 is provided with an opening 56 at its lower end, and discharges the culture solution C through the opening 56; and a flexible communication pipe 53a for interconnecting the culture tank 24a and the discharge pipe 51.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a culture system. [Background technology]

[0002] In recent years, photosynthetic microorganisms that grow by photosynthesis have been attracting attention. Algae, a type of photosynthetic microorganism, are minute phytoplankton that grow by repeated cell division in a nutrient-containing liquid. Algae grow quickly and are easy to cultivate, so there are high hopes for their effective use as an organic resource that can be used in various industries. For example, algae are used as a raw material for food, medicines, adsorbents, and oils.

[0003] As a technique for culturing such photosynthetic microorganisms, an algae culture system for culturing microalgae is described in Patent Document 1. This algae culture system includes a culture tank filled with a culture solution in which microalgae are suspended, a pump for transporting the culture solution to a dissolving section, and a dissolving section for supplying carbon dioxide to the culture solution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-65331 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the algae culture system described in Patent Document 1, the culture solution in the culture tank is sent from the culture tank to the dissolving section by a pump, so there is a risk that the algae will be cut by being caught in the pump impeller, resulting in a decrease in the culture efficiency.

[0006] The present disclosure describes a culture system that can suppress a decrease in culture efficiency. [Means for solving the problem]

[0007] A culture system according to one aspect of the present disclosure comprises a first culture tank containing a culture solution for culturing photosynthetic microorganisms, a discharge pipe extending in a vertical direction and capable of being raised and lowered in the vertical direction, the discharge pipe having a first opening at a lower end thereof and discharging the culture solution from the first opening, and a first flexible communication pipe communicating between the first culture tank and the discharge pipe. Effect of the Invention

[0008] According to each aspect and embodiment of the present disclosure, a decrease in culture efficiency can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a schematic diagram of a culture system according to one embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the culture section shown in FIG. [Diagram 3] FIG. 3 is a schematic diagram of the culture apparatus shown in FIG. [Figure 4] FIG. 4 is a flowchart showing the operation of a culture system according to one embodiment. [Diagram 5] FIG. 5 is a flowchart showing in detail the preparation process shown in FIG. [Figure 6] FIG. 6 is a diagram for explaining the discharge of the culture medium. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated descriptions are omitted. An XYZ coordinate system may be shown in each drawing. The Y-axis direction is a direction intersecting (e.g., perpendicular to) the X-axis direction and the Z-axis direction. The Z-axis direction is a direction intersecting (e.g., perpendicular to) the X-axis direction and the Y-axis direction. In this specification, "equal" does not necessarily mean strictly equal, but includes differences within a predetermined range as long as the effects of the present invention are achieved.

[0011] Fig. 1 is a diagram illustrating a schematic diagram of a culture system 1 according to one embodiment. The culture system 1 illustrated in Fig. 1 is a system for culturing photosynthetic microorganisms P. The culture system 1 is a closed culture system. The culture system 1 causes the photosynthetic microorganisms P to perform photosynthesis using sunlight, thereby cultivating the photosynthetic microorganisms P. The culture system 1 includes a culture unit 2, a discharge unit 3, a circulation unit 4, and a control unit 5.

[0012] In this embodiment, the photosynthetic microorganism P is algae. Algae are microscopic phytoplankton that grow by performing photosynthesis in a culture solution and repeating cell division. Examples of such algae include green algae (Chlorella, Chlamydomonas, Haematococcus, Botryococcus, and Dunaliella), Treboxia algae (Parachlorella), Prasinophyte, Cyanobacteria (Spirulina, Arthrostrata, Synechococcus, Synechocystis, and Nostoc), Haptophyte (Pleurochrysis), Diatom (Chaetoceros), Nannochloropsis, and Euglena. For example, Spirulina is a microscopic algae with a length of 500 μm to 600 μm, and can be a raw material for foods containing abundant nutrients. The type of photosynthetic microorganism P is not particularly limited.

[0013] The culture unit 2 will be described in detail with reference to Fig. 2 and Fig. 3. Fig. 2 is a diagram that shows a schematic representation of the culture unit 2 shown in Fig. 1. Fig. 3 is a diagram that shows a schematic representation of the culture device 23 shown in Fig. 2. The culture unit 2 is a portion that cultures photosynthetic microorganisms P. The culture unit 2 is placed outdoors so that the photosynthetic microorganisms P can perform photosynthesis. As shown in Fig. 2, the culture unit 2 includes supports 21, a beam 22, and a culture device 23.

[0014] The support 21 extends in the Z-axis direction (up-down direction). In this embodiment, the culture unit 2 includes a pair of support columns 21. The pair of support columns 21 are spaced apart from each other in the X-axis direction. The beam 22 extends in the X-axis direction. The beam 22 is spanned between the pair of support columns 21. The beam 22 is a member for supporting the culture device 23. In this embodiment, the culture unit 2 includes a plurality of beams 22 (three, for example). A beam 22 is provided for each culture device 23. The plurality of beams 22 are spaced apart from each other in the Z-axis direction. The distance between one beam 22 and another beam 22 adjacent to the one beam 22 in the Z-axis direction is longer than the length in the Z-axis direction of the culture tank 24 (described later). An example of a material for the support columns 21 and the beams 22 is metal.

[0015] The culture device 23 is a device for culturing photosynthetic microorganisms P. In this embodiment, the culture unit 2 includes a plurality of (for example, three) culture devices 23. The culture unit 2 may include only one culture device 23. Each culture device 23 is attached to a beam 22 corresponding to the culture device 23. As a result, the plurality of culture devices 23 are arranged in the Z-axis direction. As shown in FIG. 2, the culture device 23 includes a culture tank 24.

[0016] The culture tank 24 contains a culture solution C for culturing the photosynthetic microorganisms P. The culture tank 24 contains the culture solution C containing the photosynthetic microorganisms P in a closed manner. The culture tank 24 has a bag-like shape extending in the X-axis direction. The culture tank 24 is made of, for example, a light-transmitting resin sheet. As the light-transmitting resin sheet, for example, a transparent sheet made of polyethylene, nylon, urethane, or the like is used.

[0017] The culture tanks 24 are attached to the beam 22. The culture tanks 24 are suspended from the beam 22. In this embodiment, the culture unit 2 includes three culture tanks 24 arranged in the Z-axis direction. As shown in Fig. 3, the culture tanks 24 include an attachment portion 25 for attaching the culture tanks 24 to the beam 22, a main body portion 26 that defines a space for culturing the photosynthetic microorganisms P, and an upper wall portion 27 that extends in the X-axis direction and separates the attachment portion 25 and the main body portion 26 in the Z-axis direction.

[0018] The attachment portion 25 is located at the upper end of the culture tank 24, and is located above the upper wall portion 27. In this embodiment, the attachment portion 25 extends in the X-axis direction and has a cylindrical shape with both ends in the X-axis direction being open (see FIG. 2). The beam 22 is inserted into the cylindrical attachment portion 25. The upper wall portion 27 is formed, for example, by welding together the walls of the culture tank 24 facing each other in the Y-axis direction.

[0019] The main body 26 is located below the upper wall 27. The main body 26 includes a bottom 28, a side wall 29, a partition wall 30, and a bulkhead 31. The bottom 28 is a wall that constitutes the lower end of the main body 26. The bottom 28 is provided with an outlet 26a for discharging the culture solution C in the culture tank 24. In this embodiment, the outlet 26a is not provided with a valve. The side wall 29 is a wall that connects the upper wall 27 and the bottom 28. The side wall 29 is provided with a supply port 26b (see FIG. 2) for supplying the culture solution C into the culture tank 24.

[0020] The partition walls 30 divide the inside of the main body 26 of the culture tank 24 into a plurality of cells L. In this embodiment, the main body 26 includes a plurality of partition walls 30. Each partition wall 30 extends in the Z-axis direction inside the main body 26. The plurality of partition walls 30 are provided at intervals from each other in the X-axis direction. The partition walls 30 are formed, for example, by welding side wall portions 29 facing each other in the Y-axis direction. The partition walls 30 may be formed, for example, by heat sealing.

[0021] In this embodiment, an air vent slit 30a is formed between the upper end of each partition wall 30 and the upper wall portion 27. A water vent slit 30b is formed between the lower end of each partition wall 30 and the bottom portion 28. The cells L communicate with each other via the slits 30a and 30b. The liquid levels of the culture solution C in each cell L are equal to each other.

[0022] In this embodiment, the main body 26 includes a plurality of partition walls 31. Two partition walls 31 are provided in each cell L. The partition walls 31 extend in the Z-axis direction inside the main body 26. The lower end of the partition wall 31 is located above the bottom 28. A lower communication port 31a is provided between the lower end of the partition wall 31 and the bottom 28. The upper end of the partition wall 31 is located below the upper wall portion 27. An upper communication port 31b is provided between the upper end of the partition wall 31 and the upper wall portion 27. The partition wall 31 is formed, for example, by welding the side wall portions 29 facing each other in the Y-axis direction. The partition wall 31 may be formed, for example, by heat sealing.

[0023] In each cell L, two partition walls 31 divide the cell L into an air diffusion chamber 32 and a pair of culture chambers 33. The air diffusion chamber 32 is provided between the two partition walls 31 provided in the cell L. Gas is supplied to the air diffusion chamber 32 through an air diffusion hole 34 provided in the bottom 28. The air diffusion hole 34 is provided for each air diffusion chamber 32. The air diffusion hole 34 is provided below the corresponding air diffusion chamber 32. A spout for discharging gas is attached to each air diffusion hole 34. By supplying gas to the air diffusion chamber 32, an upward flow of the culture solution C is formed in the air diffusion chamber 32. The culture chamber 33 is a portion for culturing photosynthetic microorganisms P. The culture chamber 33 is formed between the partition wall 30 and the partition wall 31 that divide the cell L. The pair of culture chambers 33 sandwich the air diffusion chamber 32 in the X-axis direction.

[0024] The air diffusion chamber 32 and the culture chamber 33 extend in the Z-axis direction along the partition wall 31. The air diffusion chamber 32 and the culture chamber 33 communicate with each other below the partition wall 31 via a lower communication port 31a. The air diffusion chamber 32 and the culture chamber 33 communicate with each other above the partition wall 31 via an upper communication port 31b. The air diffusion chamber 32 and the culture chamber 33 provide a flow path for the culture solution C circulating within the main body 26 of the culture tank 24.

[0025] In this embodiment, the culture tank 24 further includes an air vent pipe 35 for venting air from inside the main body portion 26. The air vent pipe 35 is inserted through the upper wall portion 27. The air vent pipe 35 connects the inside and outside of the main body portion 26 with each other.

[0026] The culture device 23 further includes an air diffuser 41 and a temperature sensor 42. The air diffuser 41 is a device that supplies gas to the air diffusion chamber 32. The air diffuser 41 includes a blower 43 and a pipe 44. The pipe 44 is connected to the air diffusion hole 34 via the above-mentioned spout. The blower 43 supplies gas to the air diffusion chamber 32 via the pipe 44. The gas supplied by the blower 43 is, for example, air. The blower 43 supplies gas from the air diffusion hole 34 to the air diffusion chamber 32. The blower 43 may supply exhaust gas containing carbon dioxide to the air diffusion chamber 32 in order to promote photosynthesis of the photosynthetic microorganism P.

[0027] The temperature sensor 42 measures the temperature of the culture solution C in the culture tank 24. In this embodiment, the temperature sensor 42 is provided inside the main body 26. The temperature sensor 42 is capable of communicating with the control unit 5 via wired or wireless communication. The temperature sensor 42 transmits the measured value of the temperature of the culture solution C to the control unit 5.

[0028] When culturing photosynthetic microorganisms P using the culture device 23, first, culture solution C is supplied into the culture tank 24 from outside the culture tank 24. At this time, the culture solution C is supplied so that the liquid level of the culture solution C in the culture chamber 33 is a predetermined distance above the upper end of the partition wall 31. The culture solution C may be supplied so that the liquid level of the culture solution C in the culture chamber 33 is below the upper end of the partition wall 31. Next, gas is supplied from the blower 43 to the culture solution C in the multiple air diffusion chambers 32 via the multiple air diffusion holes 34.

[0029] When gas is supplied into the plurality of air diffusion chambers 32 through the plurality of air diffusion holes 34, an upward flow is formed in the culture solution C in the air diffusion chamber 32 of each cell L due to the air lift effect, and the liquid level of the culture solution C in the air diffusion chamber 32 rises. The culture solution C in the air diffusion chamber 32 that has exceeded the height of the upper end of the partition wall 31 flows into a pair of culture chambers 33 through the upper communication port 31b. The culture solution C that has flowed into the pair of culture chambers 33 forms a downward flow in the culture solution C in the pair of culture chambers 33 toward the bottom 28.

[0030] The culture solution C that moves downward within the pair of culture chambers 33 and reaches the bottom 28 is returned to the air diffusion chamber 32 through the lower communication port 31a. In this manner, in each cell L, the culture solution C in the culture tank 24 circulates between the air diffusion chamber 32 and the pair of culture chambers 33.

[0031] Hereinafter, for the sake of convenience, the uppermost culture tank 24 among the three culture tanks 24 arranged in the Z-axis direction may be referred to as the culture tank 24a (first culture tank), and the bottom 28 included in the culture tank 24a may be referred to as the bottom 28a (first bottom). The culture tank 24 adjacent to the culture tank 24a in the Z-axis direction and located below the culture tank 24a may be referred to as the culture tank 24b (second culture tank), and the bottom 28 included in the culture tank 24b may be referred to as the bottom 28b (second bottom). Among the three culture tanks 24 arranged in the Z-axis direction, the lowermost culture tank 24 may be referred to as the culture tank 24c, and the bottom 28 included in the culture tank 24c may be referred to as the bottom 28c. When it is not necessary to distinguish between the culture tanks 24, they will be simply referred to as the culture tanks 24, and when it is not necessary to distinguish between the bottoms 28, they will be simply referred to as the bottoms 28.

[0032] In this embodiment, the culture tanks 24 are arranged at equal intervals in the Z-axis direction. The culture tanks 24 have the same shape. The distance in the Z-axis direction between the bottoms 28a and 28b is equal to the distance in the Z-axis direction between the bottoms 28b and 28c.

[0033] The discharge unit 3 discharges the culture solution C from the culture unit 2. As shown in FIG. 1, the discharge unit 3 includes a discharge pipe 51, a drive unit 52, and a communication pipe 53. The discharge pipe 51 is a pipe for discharging the culture solution C in the culture tank 24. In this embodiment, the discharge pipe 51 discharges the culture solution C to a receiving tank 61 (described later). The discharge pipe 51 extends in the Z-axis direction. The discharge pipe 51 is provided spaced apart from the multiple culture tanks 24 in the X-axis direction, and communicates with each culture tank 24 via a communication pipe 53. The discharge pipe 51 is provided so as to be able to rise and fall in the Z-axis direction. By rising and falling in the Z-axis direction, the discharge pipe 51 moves relatively in the Z-axis direction with respect to each culture tank 24.

[0034] The discharge pipe 51 includes a main body portion 54 and an extension portion 55. The main body portion 54 is a portion extending in the Z-axis direction. The main body portion 54 includes an opening portion 56 (first opening portion) provided at a lower end portion of the main body portion 54. The main body portion 54 has a cylindrical shape with both ends in the Z-axis direction being open. A communicating pipe 53 is connected to the main body portion 54. The main body portion 54 discharges the culture solution C, which has flowed into the main body portion 54 from the culture tank 24 via the communicating pipe 53, from the opening portion 56 to the outside of the discharge pipe 51.

[0035] The extension portion 55 is a portion extending from the upper end of the main body portion 54. The extension portion 55 has an inverted U-shape when viewed from the Y-axis direction. The extension portion 55 is curved to describe an upwardly convex arc. The extension portion 55 includes an opening 57 (second opening) provided on the opposite side of the discharge pipe 51 from the opening 56. In other words, the opening 56 is provided at the tip of the extension portion 55. The opening 57 faces downward. Air outside the discharge pipe 51 can flow into the inside of the discharge pipe 51 through the opening 57.

[0036] The driving unit 52 is a device (actuator) that raises and lowers the discharge pipe 51. The driving unit 52 supports the discharge pipe 51 so that it can be raised and lowered. In this embodiment, the driving unit 52 is attached to the support pillar 21, out of the pair of supports 21, that is closer to the discharge pipe 51. The driving unit 52 raises and lowers the discharge pipe 51 based on a command from the control unit 5. The driving unit 52 is, for example, an air cylinder. In this case, the driving unit 52 may include a compressor that is a power source for the air cylinder. The driving unit 52 may be a hydraulic cylinder or an electric cylinder.

[0037] The communication pipe 53 communicates the culture tank 24 with the discharge pipe 51. The communication pipe 53 is a pipe for discharging the culture solution C containing the photosynthetic microorganisms P from the culture tank 24. The communication pipe 53 is flexible. The communication pipe 53 includes one end 58 connected to the discharge port 26a provided at the bottom 28 of the culture tank 24 and the other end 59 connected to the main body 54 of the discharge pipe 51. For example, when the culture solution C is discharged from the culture tank 24, the culture solution C in the culture tank 24 flows to the discharge pipe 51 through the communication pipe 53. The communication pipe 53 is not provided with a pump for sending the culture solution C in the culture tank 24 to the outside of the culture tank 24, for example.

[0038] In this embodiment, the discharge section 3 includes the same number of communicating pipes 53 as the culture device 23. Hereinafter, for convenience of explanation, the communicating pipe 53 that communicates the culture tank 24a and the discharge pipe 51 may be referred to as the communicating pipe 53a (first communicating pipe), the communicating pipe 53 that communicates the culture tank 24b and the discharge pipe 51 may be referred to as the communicating pipe 53b (second communicating pipe), and the communicating pipe 53 that communicates the culture tank 24c and the discharge pipe 51 may be referred to as the communicating pipe 53c. One end 58 of the communicating pipe 53a may be referred to as the one end 58a (first end), and the other end 59 of the communicating pipe 53a may be referred to as the other end 59a (second end). One end 58 of the communicating pipe 53b may be referred to as the one end 58b (third end), and the other end 59 of the communicating pipe 53b may be referred to as the other end 59b (fourth end). One end 58 of the communicating pipe 53c may be referred to as one end 58c, and the other end 59 of the communicating pipe 53c may be referred to as the other end 59c.

[0039] The distance D1 between one end 58a and one end 58b in the Z-axis direction is equal to the distance H1 between the other end 59a and the other end 59b in the Z-axis direction. The distance D2 between one end 58b and one end 58c in the Z-axis direction is equal to the distance H2 between the other end 59b and the other end 59c in the Z-axis direction. Note that the distance D1 is the same as the distance between the bottom portion 28a and the bottom portion 28b in the Z-axis direction, and the distance D2 is the same as the distance between the bottom portion 28b and the bottom portion 28c in the Z-axis direction. In this embodiment, the distance D1 is equal to the distance D2, and the distance H1 is equal to the distance H2, but the distance D1 may be different from the distance D2, and the distance H1 may be different from the distance H2.

[0040] The circulation unit 4 supplies the culture solution C discharged by the discharge unit 3 to the culture unit 2. The circulation unit 4 includes a receiving tank 61, a liquid level gauge 62 (liquid volume measuring unit), a pH meter 63, a concentration meter 64, a supply pipe 65, a pump 66 (supply unit), a branch pipe 67, a water distribution pipe 68, and a return pipe 69.

[0041] The receiving tank 61 stores the culture solution C discharged from the opening 56 of the discharge pipe 51. In this embodiment, the receiving tank 61 is provided below the discharge pipe 51. The receiving tank 61 may be connected to the opening 56 of the discharge pipe 51 via, for example, piping. In this case, the location of the receiving tank 61 is not particularly limited. The capacity of the receiving tank 61 is larger than the total amount of culture solution C supplied to all of the culture tanks 24 included in the culture unit 2. The receiving tank 61 has, for example, a rectangular parallelepiped shape.

[0042] The level gauge 62 measures the level of the culture solution C stored in the receiving tank 61. For example, a guide pulse type or ultrasonic type level gauge is used as the level gauge 62. The level gauge 62 is provided in the receiving tank 61 so as to be able to measure the level of the culture solution C in the receiving tank 61. The level gauge 62 is capable of communicating with the control unit 5 by wire or wirelessly. The level gauge 62 transmits the measurement value of the level of the culture solution C to the control unit 5.

[0043] The pH meter 63 measures the pH value of the culture solution C stored in the receiving tank 61. The pH meter 63 is provided in the receiving tank 61 so as to be able to measure the pH value of the culture solution C in the receiving tank 61. The pH meter 63 is capable of communicating with the control unit 5 via a wire or wirelessly. The pH meter 63 transmits the measured pH value of the culture solution C to the control unit 5.

[0044] The concentration meter 64 measures the concentration of the culture solution C stored in the receiving tank 61. The concentration meter 64 is provided in the receiving tank 61 so as to be able to measure the concentration of the culture solution C in the receiving tank 61. The concentration meter 64 measures, for example, the SS (Suspended Solids) concentration of the culture solution C as the concentration of the culture solution C. The concentration meter 64 is capable of communicating with the control unit 5 via a wired or wireless connection. The concentration meter 64 transmits the measured value of the concentration of the culture solution C to the control unit 5.

[0045] The supply pipe 65 is a pipe for supplying the culture solution C stored in the receiving tank 61 to the culture tank 24. One end of the supply pipe 65 is connected to the receiving tank 61. The other end of the supply pipe 65 is connected to a water distribution pipe 68.

[0046] The pump 66 supplies the culture solution C stored in the receiving tank 61 to the culture tank 24. In this embodiment, the pump 66 is provided in the supply pipe 65. When the pump 66 is driven, the culture solution C stored in the receiving tank 61 flows into the culture tank 24 via the supply pipe 65, the water distribution pipe 68, and the branch pipe 67. The pump 66 starts or stops the supply of the culture solution C based on a command from the control unit 5.

[0047] The water dividing pipe 68 branches the culture solution C supplied from the receiving tank 61 via the supply pipe 65 into each branch pipe 67. The water dividing pipe 68 is provided above the culture tank 24a.

[0048] The branch pipe 67 is a pipe that connects the water distribution pipe 68 and the culture tank 24. In this embodiment, the circulation unit 4 includes the same number of branch pipes 67 as the culture devices 23. One end of each branch pipe 67 is connected to the water distribution pipe 68. The other end of each branch pipe 67 is connected to the supply port 26b (see FIG. 2) of each culture tank 24. The diameter of the branch pipe 67 is smaller than the diameter of the supply pipe 65. The diameter of the branch pipe 67 is, for example, 10 mm.

[0049] The lengths of the multiple branch pipes 67 are different from one another. The length of the branch pipe 67 connected to the culture tank 24a is shorter than the length of the branch pipe 67 connected to the culture tank 24b. The length of the branch pipe 67 connected to the culture tank 24b is shorter than the length of the branch pipe 67 connected to the culture tank 24c.

[0050] The return pipe 69 is a pipe for returning a portion of the culture solution C supplied from the receiving tank 61 by the pump 66 back to the receiving tank 61. More specifically, the return pipe 69 returns the culture solution C supplied from the receiving tank 61 via the supply pipe 65 that has not been supplied to the culture tank 24 back to the receiving tank 61. One end of the return pipe 69 is connected to the water distribution pipe 68. The other end of the return pipe 69 is connected to the receiving tank 61.

[0051] In this embodiment, a valve 69a is provided in the return pipe 69. The valve 69a adjusts the amount of culture solution C returned to the receiving tank 61 via the return pipe 69. By operating the valve 69a, the amount of culture solution C supplied to the culture tank 24 can be adjusted.

[0052] The control unit 5 is a controller that performs overall control of the culture system 1. The control unit 5 is configured as a computer including, for example, a processor such as a CPU (Central Processing Unit), memories such as a RAM (Random Access Memory) and a ROM (Read Only Memory), input devices such as a touch panel, a mouse, and a keyboard, output devices such as a display, and a communication device such as a network card. The functions of the control unit 5 are realized by operating each piece of hardware under the control of the processor based on a computer program stored in the memory.

[0053] The control unit 5 controls each unit of the culture system 1. For example, the control unit 5 controls the drive unit 52. The control unit 5 drives the drive unit 52 to raise and lower the discharge pipe 51, which is supported by the drive unit 52 so that it can be raised and lowered. The control unit 5 adjusts the height of the discharge pipe 51 by controlling the drive amount of the drive unit 52. The control unit 5 supplies the culture solution C to each culture tank 24 by controlling the drive unit 52 and the pump 66, and discharges the culture solution C from each culture tank 24 by controlling the drive unit 52. The supply and discharge of the culture solution C will be described in detail later.

[0054] The control unit 5 checks the state of the culture solution C based on the measured values ​​obtained from the temperature sensor 42, the pH meter 63, and the concentration meter 64.

[0055] The control unit 5 controls the blower 43. The control unit 5 drives the blower 43 to supply gas to the air diffusion chamber 32 via a pipe 44.

[0056] Next, the operation of the culture system 1 will be described with reference to FIG. 1 and FIG. 4 to FIG. 6. FIG. 4 is a flowchart showing the operation of the culture system 1 according to one embodiment. FIG. 5 is a flowchart showing in detail the preparation process shown in FIG. 4. FIG. 6 is a diagram for explaining the discharge of the culture solution C. Before the culture system 1 is operated, the discharge pipe 51 is located at the discharge height. The discharge height is the height of the discharge pipe 51 for discharging all of the culture solution C from all of the culture tanks 24 included in the culture unit 2. In this embodiment, the discharge height is set so that the other end 59 of each communication pipe 53 is located below the bottom 28 of the culture tank 24 to which the communication pipe 53 is connected. The discharge height is set in advance, for example.

[0057] Before the culture system 1 is operated, each culture tank 24 does not contain the culture solution C. The receiving tank 61 stores an amount of culture solution C that is greater than the total predetermined capacity of all the culture tanks 24 included in the culture unit 2. The predetermined capacity is the amount of culture solution C contained in the culture tank 24 when the culture system 1 starts culturing the photosynthetic microorganism P. In this embodiment, the predetermined capacity is the amount of culture solution C that causes the liquid level of the culture solution C in the culture tank 24 to be a predetermined distance above the upper end of the partition wall 31. The predetermined capacity may also be the amount of culture solution C that causes the liquid level of the culture solution C in the culture tank 24 to be lower than the upper end of the partition wall 31.

[0058] 4 is started when a start condition is satisfied. For example, the start condition is satisfied when the control unit 5 receives a command to start culturing the photosynthetic microorganisms P. The command may be transmitted to the control unit 5 by, for example, a user of the culture system 1 via a device provided outside the culture system 1 (hereinafter referred to as an "external device"). The start condition may be satisfied when a preset start time is reached.

[0059] First, the control unit 5 performs a preparation process for the culture tank 24 (step S1). In the preparation process for the culture tank 24, as shown in FIG. 5, the control unit 5 controls the drive unit 52 to move the discharge pipe 51 to the supply height (predetermined height) (step S11). The supply height is the height of the discharge pipe 51 for storing a predetermined amount of culture solution C in all the culture tanks 24 included in the culture unit 2, and is, for example, the height of the discharge pipe 51 shown in FIG. 1. Specifically, the supply height is set so that the other end 59 of each communication pipe 53 is at the same height as the liquid level of the culture solution C at the start of the culture of the photosynthetic microorganism P in the culture tank 24 to which the communication pipe 53 is connected. In this embodiment, the supply height is set so that the other end 59 of each communication pipe 53 is located above the upper end of the partition wall 31 in the culture tank 24 to which the communication pipe 53 is connected by the above-mentioned predetermined distance. The supply height is, for example, set in advance. The supply height may be set so that the other end 59 of each communicating pipe 53 is located below the upper end of the partition wall 31 in the culture tank 24 to which the communicating pipe 53 is connected. In step S11, the control unit 5 raises the discharge pipe 51 and moves the discharge pipe 51 to the supply height.

[0060] Next, the control unit 5 drives the pump 66 to start supplying the culture solution C (step S12). In step S12, the control unit 5 drives the pump 66 to supply the culture solution C stored in the receiving tank 61 to each culture tank 24 via the supply pipe 65, the water distribution pipe 68, and the branch pipe 67.

[0061] Next, the control unit 5 judges whether a predetermined time has elapsed since the start of the supply of the culture solution C and the liquid amount in the receiving tank 61 is equal to or less than the predetermined liquid amount (step S13). The predetermined liquid amount is a threshold value for judging whether a predetermined capacity of the culture solution C is accommodated in all the culture tanks 24 included in the culture unit 2. For example, the predetermined liquid amount is set to a remaining amount obtained by subtracting the total of the predetermined capacity of all the culture tanks 24 included in the culture unit 2 from the liquid amount of the culture solution C stored in the receiving tank 61 before the culture system 1 is operated. The predetermined liquid amount may be set to a value slightly smaller than the remaining amount so that the preparation process of the culture tank 24 in step S1 can be completed. The predetermined liquid amount may be set to a value slightly larger than the remaining amount so that the liquid levels of all the culture tanks 24 included in the culture unit 2 are approximately the same. The predetermined time is, for example, 4 minutes to 6 minutes. For example, a time at which the amount of the culture solution C supplied by the pump 66 becomes larger than the total of the predetermined capacity of all the culture tanks 24 may be adopted as the predetermined time.

[0062] In step S13, the control unit 5 acquires a measurement value of the liquid level of the culture solution C stored in the receiving tank 61, measured by the liquid level gauge 62. Then, the control unit 5 calculates the amount of the culture solution C stored in the receiving tank 61 based on the acquired measurement value of the liquid level. More specifically, the control unit 5 calculates the product of the bottom area of ​​the receiving tank 61 and the acquired liquid level as the amount of the culture solution C stored in the receiving tank 61.

[0063] In step S13, if it is determined that a predetermined time has not elapsed since the start of the supply of the culture solution C, or if it is determined that the amount of liquid in the receiving tank 61 is greater than the predetermined amount of liquid (step S13: NO), it is considered that not all of the culture tanks 24 included in the culture unit 2 contain the predetermined amount of culture solution C. In this case, the control unit 5 starts the supply of the culture solution C again and repeats steps S12 and S13. On the other hand, in step S13, if it is determined that a predetermined time has elapsed since the start of the supply of the culture solution C and that the amount of liquid in the receiving tank 61 is equal to or less than the predetermined amount of liquid (step S13: YES), it is considered that all of the culture tanks 24 included in the culture unit 2 contain the predetermined amount of culture solution C, as shown in FIG. 1. Therefore, the control unit 5 stops the supply of the culture solution C by stopping the pump 66 (step S14), and ends the preparation process for the culture tanks 24 in step S1.

[0064] When the culture solution C is supplied to the culture tank 24 in an amount exceeding the predetermined capacity of the culture tank 24, the culture solution C in an amount exceeding the predetermined capacity of the culture tank 24 flows to the discharge pipe 51 via the communication pipe 53 due to the action of the hydraulic head pressure. The culture solution C that has flowed to the discharge pipe 51 is discharged from the opening 56 of the discharge pipe 51 to the receiving tank 61 and is supplied again to the culture tank 24 by the pump 66.

[0065] Next, the control unit 5 cultures the photosynthetic microorganisms P (step S2). In step S2, the control unit 5 drives the blower 43 to supply gas to the air diffusion chamber 32 via the pipe 44. As a result, in each cell L, the culture solution C circulates between the air diffusion chamber 32 and the pair of culture chambers 33, and the culture solution C in the culture tank 24 is stirred. In this state, the culture tank 24 receives light, causing the photosynthetic microorganisms P contained in the culture solution C to perform photosynthesis.

[0066] Next, the control unit 5 determines whether or not the measurement timing has arrived (step S3). The measurement timing is, for example, a point in time when a preset cycle time has elapsed since the start of the culture. If it is determined that the measurement timing has not arrived (step S3: NO), the control unit 5 repeats steps S2 and S3 until the measurement timing arrives. On the other hand, if it is determined in step S3 that the measurement timing has arrived (step S3: YES), the control unit 5 checks the state of the culture solution C in the culture tank 24 (step S4).

[0067] In step S4, the control unit 5 discharges a preset amount of the culture solution C from each culture tank 24 to the receiving tank 61. Specifically, as shown in FIG. 6, the control unit 5 drives the drive unit 52 to lower the discharge pipe 51 from the supply height to the measurement height. The measurement height is preset according to the amount of the culture solution C to be withdrawn. As a result, the height of the other end 59 of each communication pipe 53 becomes lower than the liquid level of the culture solution C in the culture tank 24 to which the communication pipe 53 is connected. Then, due to the action of the head pressure, the culture solution C in the culture tank 24 flows into the discharge pipe 51 through the communication pipe 53 until the liquid level of the culture solution C in the culture tank 24 becomes equal to the height of the other end 59 of the communication pipe 53 connected to the culture tank 24. The culture solution C that has flowed into the discharge pipe 51 falls according to gravity and is discharged from the opening 56 of the discharge pipe 51 into the receiving tank 61.

[0068] In addition, the control unit 5 may determine whether or not the withdrawn amount of culture solution C has been discharged from all of the culture tanks 24 included in the culture unit 2 based on the measured liquid level height of the culture solution C stored in the receiving tank 61 measured by the liquid level gauge 62.

[0069] Then, the control unit 5 acquires the measured pH value of the culture solution C measured by the pH meter 63 and the measured concentration of the culture solution C measured by the concentration meter 64. Then, the control unit 5 judges whether or not the measured pH value is within an allowable pH range. The lower and upper thresholds of the allowable pH range are set in advance, for example, and can be changed as appropriate. If it is judged that the measured pH value is outside the allowable pH range, the control unit 5 transmits abnormality information indicating that the culture solution C is abnormal to the above-mentioned external device.

[0070] Similarly, the control unit 5 judges whether the measured value of the concentration is within the allowable range of the concentration. The lower and upper thresholds of the allowable range of the concentration are, for example, set in advance and can be changed as appropriate. If it is judged that the measured value of the concentration is outside the allowable range of the concentration, the control unit 5 transmits abnormality information indicating that the culture solution C is abnormal to the above-mentioned external device. Then, upon receiving the abnormality information, the external device notifies the user of the culture system 1 that the culture solution C is abnormal.

[0071] Next, the control unit 5 judges whether or not the end condition is satisfied (step S5). In step S5, the control unit 5 judges that the end condition is satisfied when, for example, a command instructing to end the cultivation of the photosynthetic microorganism P is received. The command may be transmitted to the control unit 5 via an external device at any timing (for example, during maintenance) by, for example, a user of the cultivation system 1. In step S5, if it is judged that the end condition is not satisfied (step S5: NO), the control unit 5 repeats steps S1 to S5 until the end condition is satisfied. Note that, in step S1 from the second time onwards, the predetermined time may be a time when the amount of the culture solution C supplied by the pump 66 becomes greater than the total amount of the culture solution C extracted from all the culture tanks 24 in step S4.

[0072] On the other hand, when it is determined in step S5 that the termination condition is satisfied (step S5: YES), the control unit 5 recovers the culture solution C from each culture tank 24 (step S6). In step S6, the control unit 5 discharges the entire amount of the culture solution C contained in each culture tank 24 from each culture tank 24 to the receiving tank 61. Specifically, the control unit 5 drives the drive unit 52 to lower the discharge pipe 51 to the discharge height. As described above, the discharge height is set so that the other end 59 of each communication pipe 53 is located lower than the bottom 28 of the culture tank 24 to which the communication pipe 53 is connected. Therefore, due to the action of the head pressure, the culture solution C in the culture tank 24 flows into the discharge pipe 51 through the communication pipe 53 until all of the culture solution C in the culture tank 24 is discharged. The culture solution C that has flowed into the discharge pipe 51 falls according to gravity and is collected into the receiving tank 61 from the opening 56 of the discharge pipe 51.

[0073] In addition, the control unit 5 may determine whether or not all of the culture solution C has been discharged from all of the culture tanks 24 included in the culture unit 2 based on the measurement value of the liquid level height of the culture solution C stored in the receiving tank 61 measured by the liquid level gauge 62.

[0074] With the above, the series of operations shown in FIG. 4 is completed.

[0075] In step S4, the control unit 5 may check the state of the culture solution C based on the measured value of the temperature of the culture solution C acquired from the temperature sensor 42. For example, the control unit 5 determines whether or not the measured value of the temperature acquired is within an allowable temperature range. The lower and upper thresholds of the allowable temperature range are, for example, set in advance and can be changed as appropriate. If it is determined that the measured value of the temperature is outside the allowable temperature range, the control unit 5 transmits abnormality information indicating that the culture solution C is abnormal to the above-mentioned external device. The check of the state of the culture solution C based on the measured value of the temperature of the culture solution C may be performed at a timing different from step S4.

[0076] In FIG. 4, step S5 is performed after step S4, but step S5 may be performed at any timing.

[0077] In the above-described culture system 1, when the discharge pipe 51 moves downward and the height of the other end 59 of the communicating pipe 53 becomes lower than the liquid level of the culture solution C in the culture tank 24 to which the communicating pipe 53 is connected, the culture solution C flows into the discharge pipe 51 through the communicating pipe 53 due to the action of the hydraulic head pressure. The culture solution C that has flowed into the discharge pipe 51 is discharged from an opening 56 provided at the lower end of the discharge pipe 51. Therefore, since the culture solution C can be discharged from the culture tank 24 without using a device such as a pump, it is possible to prevent the photosynthetic microorganisms P from being cut off by being caught in the impeller of the pump when the culture solution C is discharged. As a result, a decrease in the culture efficiency of the photosynthetic microorganisms P can be suppressed.

[0078] More specifically, the culture system 1 includes a plurality of culture tanks 24 and a flexible communication pipe 53 that communicates each culture tank 24 with the discharge pipe 51. According to this configuration, since the photosynthetic microorganisms P are cultured in the plurality of culture tanks 24, the photosynthetic microorganisms P can be efficiently cultured. Since each culture tank 24 and the discharge pipe 51 communicate with each other via the communication pipe 53, the culture solution C can be discharged from all the culture tanks 24 simply by moving the discharge pipe 51 downward. Therefore, the culture solution C can be efficiently discharged from all the culture tanks 24 without using a device such as a pump. In the culture system 1, since it is not necessary to provide a valve or the like at the discharge port 26a of each culture tank 24, the configuration of the culture system 1 can be simplified.

[0079] In the culture system 1, one end 58 of each communicating pipe 53 is connected to the bottom 28 of the culture tank 24 corresponding to the communicating pipe 53. Therefore, by moving the discharge pipe 51 downward, it is possible to discharge all of the culture solution C in each culture tank 24. Therefore, by appropriately setting the supply height, it is possible to adjust the amount of the culture solution C in each culture tank 24 to a desired amount.

[0080] In the culture system 1, the culture tank 24a, the culture tank 24b, and the culture tank 24c are arranged in that order in the Z-axis direction. When the discharge pipe 51 moves downward, the liquid level in the culture tank 24a drops to the height of the other end 59a, the liquid level in the culture tank 24b drops to the height of the other end 59b, and the liquid level in the culture tank 24c drops to the height of the other end 59c. Here, since the distance D1 is equal to the distance H1 and the distance D2 is equal to the distance H2, the liquid level heights of the three culture tanks 24 can be made equal to each other. Since the three culture tanks 24 have the same shape and size, the amount of the culture solution C in all the culture tanks 24 can be made equal to each other.

[0081] For example, when the amount of culture solution C extracted from each culture tank 24 is discharged and then each culture tank 24 is replenished with culture solution C, the concentrations of the culture solution C in all culture tanks 24 can be made equal to each other. Therefore, the light receiving efficiency becomes uniform in all culture tanks 24, and the growth conditions of the photosynthetic microorganisms P can be made equal to each other in all culture tanks 24. As a result, the photosynthetic microorganisms P can be stably cultured.

[0082] For example, in the case where the end opposite to the lower end of the discharge pipe 51 is blocked, when the culture solution C flows from the communicating pipe 53 into the discharge pipe 51, negative pressure may be generated in the space between the connecting port of the communicating pipe 53 in the discharge pipe 51 and the end. In this case, the culture solution C is less likely to flow through the discharge pipe 51, and the discharge efficiency of the culture solution C may decrease. On the other hand, in the culture system 1, the discharge pipe 51 has an opening 57 provided on the opposite side to the opening 56, so that the possibility of negative pressure being generated in the space by air outside the discharge pipe 51 entering the space through the opening 57 can be reduced. As a result, the culture solution C can be efficiently discharged. For example, when a siphon phenomenon occurs, there is a possibility that an unintended amount of the culture solution C is discharged in some of the culture tanks 24. On the other hand, in the culture system 1, the discharge pipe 51 has an opening 57, so that the possibility of the siphon phenomenon occurring can be reduced. Therefore, the possibility of an unintended amount of the culture solution C being discharged in some of the culture tanks 24 can be reduced.

[0083] In the culture system 1, the opening 57 faces downward, so that the possibility of foreign matter such as raindrops entering the inside of the discharge pipe 51 through the opening 57 can be reduced.

[0084] In the culture system 1, the control unit 5 restarts the supply of the culture solution C when a predetermined time has elapsed since the start of the supply of the culture solution C and the condition that the amount of liquid in the receiving tank 61 is equal to or less than the predetermined amount of liquid is not satisfied. According to this configuration, the culture solution C can be accommodated in each culture tank 24 up to the height of the connection position (other end 59) between the discharge pipe 51 and the communicating pipe 53 connected to the culture tank 24. For example, when the culture solution C is accommodated in each culture tank 24 up to the height of the connection position between the discharge pipe 51 and the communicating pipe 53 with the discharge pipe 51 positioned at the supply height, the amount of the culture solution C remaining in the receiving tank 61 can be set as the predetermined amount of liquid, so that a predetermined amount of the culture solution C can be accommodated in each culture tank 24.

[0085] In the culture system 1, when the measured value of the temperature of the culture solution C is determined to be outside the allowable temperature range, when the measured value of the pH value of the culture solution C is determined to be outside the allowable pH range, or when the measured value of the concentration of the culture solution C is determined to be outside the allowable concentration range, the control unit 5 transmits abnormality information indicating that the culture solution C is abnormal to the above-mentioned external device. According to this configuration, the user of the culture system 1 can sense the abnormality of the culture system 1 via the above-mentioned external device, and appropriate culture management and rapid response to the abnormality can be realized.

[0086] In the culture system 1, the circulation unit 4 includes branch pipes 67 in the same number as the culture devices 23. The branch pipes 67 are connected to a water distribution pipe 68 provided above the culture tank 24a. When the culture solution C in the receiving tank 61 is supplied to each culture tank 24, the culture solution C is raised above the culture tank 24a and then supplied to each culture tank 24 through each branch pipe 67. The smaller the diameter of the branch pipe 67, the higher the discharge pressure of the culture solution C. The diameter of the branch pipe 67 is set to a level at which a discharge pressure that can ignore the influence of the siphon effect can be obtained. Therefore, even if the lengths of the multiple branch pipes 67 are different from each other, the culture solution C can be evenly supplied to each culture tank 24 with almost no influence of the siphon effect.

[0087] The culture system according to the present disclosure is not limited to the above embodiment.

[0088] The control unit 5 may be capable of changing the type of gas supplied to the air diffusion chamber 32 by the blower 43. For example, the blower 43 may be capable of supplying air or carbon dioxide to the air diffusion chamber 32. In this case, when it is determined that the pH value transmitted from the pH meter 63 is greater than the upper limit threshold of the allowable range of the pH value, the control unit 5 may drive the blower 43 to supply carbon dioxide to the air diffusion chamber 32.

[0089] The culture system 1 may be configured to recover the photosynthetic microorganisms P contained in the culture solution C stored in the receiving tank 61. In this case, for example, the culture system 1 further includes a pipe for discharging the culture solution C stored in the receiving tank 61 to the outside of the receiving tank 61, and a pump provided in the pipe. In this configuration, when it is determined that the measured value of the concentration transmitted from the concentration meter 64 is greater than the upper threshold of the allowable range of the concentration, the control unit 5 may drive the pump to discharge the culture solution C stored in the receiving tank 61 to the outside of the receiving tank 61 through the pipe. Furthermore, the culture solution C discharged to the outside of the receiving tank 61 may be filtered to recover the photosynthetic microorganisms P. The recovered photosynthetic microorganisms P may be dehydrated and dried, for example, outside the culture system 1. The dried photosynthetic microorganisms P may be packaged and shipped as a product, for example.

[0090] When it is determined that the measured value of the concentration transmitted from the concentration meter 64 is greater than the upper threshold of the allowable range of the concentration, the control unit 5 may discharge the amount of the culture solution C calculated based on the measured value of the concentration from the culture tank 24. In this case, the control unit 5 calculates the concentration of the culture solution C in the culture tank 24, for example, on the assumption that the culture solution C not containing the photosynthetic microorganism P is supplied to the culture tank 24 in the same amount as the discharge amount of the culture solution C to the culture solution C remaining in the culture tank 24 after the culture solution C is discharged. Then, the control unit 5 calculates the discharge amount of the culture solution C such that the calculated concentration of the culture solution C falls within the allowable range of the concentration. Then, the control unit 5 adjusts the height of the discharge pipe 51 by controlling the drive amount of the drive unit 52 so that the culture solution C is discharged from the culture tank 24 by the calculated discharge amount.

[0091] At the timing when the culture solution C flows from the culture tank 24 to the discharge pipe 51 through the communicating pipe 53, the control unit 5 may drive the drive unit 52 to raise the discharge pipe 51, thereby stopping the discharge of the culture solution C. When the control unit 5 raises the discharge pipe 51, the height of the other end 59 of the communicating pipe 53 becomes higher than the liquid level of the culture solution C in the culture tank 24 to which the communicating pipe 53 is connected. Then, the culture solution C in the culture tank 24 stops flowing to the discharge pipe 51, and the discharge of the culture solution C is stopped.

[0092] In the above embodiment, the receiving tank 61 stores a sufficient amount of culture solution C, but the amount of culture solution C stored in the receiving tank 61 may be changed as appropriate. In this case, after performing step S11 and before performing step S12, the control unit 5 may determine whether the amount of culture solution C stored in the receiving tank 61 is equal to or greater than a set amount. The set amount is, for example, the total of the predetermined capacity of all the culture tanks 24 included in the culture unit 2. For example, in step S13, the control unit 5 may obtain the amount of culture solution C in the receiving tank 61 by a method similar to the method for measuring the amount of culture solution C in the receiving tank 61, and determine whether the obtained amount is equal to or greater than the set amount.

[0093] In this case, the culture system 1 may further include a spare medium tank (not shown) for storing the culture solution C, and a pump (not shown) for supplying the culture solution C from the spare medium tank to the receiving tank 61. For example, when it is determined that the amount of the culture solution C stored in the receiving tank 61 is equal to or greater than a set amount, the control unit 5 executes step S12. When it is determined that the amount of the culture solution C stored in the receiving tank 61 is less than the set amount, the control unit 5 drives the pump to supply the shortage of culture solution C from the spare medium tank to the receiving tank 61.

[0094] In the above embodiment, one end 58 of the communicating pipe 53 is connected to the bottom 28 of the culture tank 24. However, one end 58 of the communicating pipe 53 may be connected to the side wall 29 of the culture tank 24.

[0095] In the above embodiment, the multiple culture vessels 24 are arranged in the Z-axis direction, but they may be arranged in a direction different from the Z-axis direction.

[0096] In the above embodiment, the distance D1 is equal to the distance H1, but the distance D1 may be different from the distance H1. In the above embodiment, the distance D2 is equal to the distance H2, but the distance D2 may be different from the distance H2.

[0097] For example, when the inner diameter of the discharge pipe 51 is sufficiently large relative to the flow rate of the culture solution C discharged from the culture tank 24, even if the end opposite the lower end of the discharge pipe 51 is closed, negative pressure is unlikely to be generated in the space between the connection port of the communicating pipe 53 in the discharge pipe 51 and the end. In such a case, the discharge pipe 51 does not need to include the opening 57.

[0098] The opening 57 does not have to face downward, but may face to the side or upward. A filter may be provided in the opening 57 to prevent entry of foreign matter.

[0099] In the above embodiment, the control unit 5 calculates the volume of the culture solution C stored in the receiving tank 61 based on the measurement value of the liquid level obtained from the liquid level gauge 62, and determines whether the calculated volume is equal to or less than a predetermined volume. However, the control unit 5 may also determine whether the measurement value of the liquid level height obtained from the liquid level gauge 62 is equal to or less than a predetermined liquid level.

[0100] Finally, an overview of the embodiments of the present disclosure will be described.

[0101] (Clause 1) A first culture tank containing a culture solution for culturing photosynthetic microorganisms; a discharge pipe extending in a vertical direction and movable up and down in the vertical direction, the discharge pipe having a first opening at a lower end thereof, the discharge pipe discharging the culture medium from the first opening; A first communication pipe that communicates the first culture tank and the discharge pipe and has flexibility; Equipped with Culture system.

[0102] In this culture system, when the discharge pipe moves downward and the height of the connection position between the discharge pipe and the first communicating pipe becomes lower than the liquid level of the culture liquid in the culture tank, the culture liquid flows into the discharge pipe via the first communicating pipe, for example, due to the action of hydraulic head pressure. The culture liquid that has flowed into the discharge pipe is discharged from a first opening provided at the lower end of the discharge pipe. Therefore, the culture liquid can be discharged from the culture tank without using a device such as a pump, and a decrease in the culture efficiency of photosynthetic microorganisms can be suppressed.

[0103] (Clause 2) The first culture tank has a bottom, The first communication pipe is A first end connected to the bottom; and a second end connected to the exhaust pipe. 2. A culture system according to clause 1.

[0104] According to this configuration, since the first end of the first communicating pipe is connected to the bottom of the first culture tank, the culture medium in the first culture tank can be entirely discharged by moving the discharge pipe downward. Therefore, the amount of culture medium in the culture tank can be adjusted to a desired amount.

[0105] (Clause 3) A second culture tank containing the culture solution for culturing the photosynthetic microorganism; Further comprising a second communicating pipe that communicates the second culture tank and the discharge pipe and has flexibility; 2. A culture system according to clause 1.

[0106] According to this configuration, the culture system includes a second culture tank in addition to the first culture tank, so that photosynthetic microorganisms can be cultured efficiently. Since the second culture tank and the discharge pipe are connected to each other via the second communication pipe, the culture medium can be discharged from both the first culture tank and the second culture tank simply by moving the discharge pipe downward. Therefore, even when culturing photosynthetic microorganisms using the second culture tank in addition to the first culture tank, the culture medium can be discharged from both culture tanks without using a device such as a pump.

[0107] (Clause 4) The first culture tank has a first bottom, The first communication pipe is a first end connected to the first bottom; and a second end connected to the exhaust pipe. The second culture tank has a second bottom, The second communication pipe is a third end connected to the second bottom; a fourth end connected to the exhaust pipe; The first culture tank and the second culture tank are arranged in the vertical direction, The distance between the first end and the third end is equal to the distance between the second end and the fourth end. 4. A culture system according to clause 3.

[0108] When the discharge pipe moves downward, the liquid level in the first culture tank drops to the height of the second end, and the liquid level in the second culture tank drops to the height of the fourth end. Here, since the distance between the first end and the third end is equal to the distance between the second end and the fourth end, the liquid levels in the first culture tank and the second culture tank can be made equal to each other.

[0109] (Clause 5) The exhaust pipe is a main body portion including the first opening, extending in the vertical direction, and connected to the first communicating pipe; The second opening is provided on the opposite side to the first opening, and an extension portion extends from an upper end of the main body portion. A culture system according to any one of claims 1 to 4.

[0110] For example, if the end opposite to the lower end of the discharge pipe is closed, when the culture fluid flows from the first communicating pipe into the discharge pipe, negative pressure may be generated in the space between the connection port of the first communicating pipe and the end of the discharge pipe. In this case, the culture fluid may not flow easily through the discharge pipe, and the efficiency of discharging the culture fluid may decrease. Since the discharge pipe has a second opening provided on the opposite side to the first opening, it is possible to reduce the possibility that negative pressure will be generated in the space by air outside the discharge pipe entering the space through the second opening. As a result, the culture fluid can be efficiently discharged.

[0111] (Clause 6) The second opening faces downward. 6. The culture system according to clause 5.

[0112] According to this configuration, since the second opening faces downward, it is possible to reduce the possibility that foreign matter such as raindrops will enter the inside of the exhaust pipe through the second opening.

[0113] (Clause 7) A receiving tank that stores the culture solution discharged from the first opening of the discharge pipe; A liquid volume measuring unit that measures the volume of the culture liquid stored in the receiving tank; A supply unit that supplies the culture solution stored in the receiving tank to the first culture tank; A drive unit that raises and lowers the discharge pipe; A control unit that controls the supply unit and the drive unit, The control unit is By controlling the drive unit, the discharge pipe is moved to a predetermined height; With the discharge pipe positioned at the predetermined height, the supply unit is controlled to start supplying the culture medium; determining whether or not a condition is satisfied that a predetermined time has elapsed since the start of the supply of the culture medium and that the amount of the medium is equal to or less than a predetermined amount of the medium; If it is determined that the condition is not satisfied, restarting the supply of the culture medium; If it is determined that the condition is satisfied, the supply of the culture medium is stopped. A culture system according to any one of clauses 1 to 6.

[0114] According to this configuration, the culture medium is supplied to the first culture tank, and it is determined whether or not a condition is satisfied that a predetermined time has elapsed since the start of the supply of the culture medium and the liquid volume is equal to or less than a predetermined liquid volume. If it is determined that the above condition is not satisfied, the supply of the culture medium is started again. The first culture tank can contain the culture medium up to the height of the connection position between the discharge pipe and the first communicating pipe. For example, when the discharge pipe is located at a predetermined height and the culture medium is contained in the first culture tank up to the height of the connection position between the discharge pipe and the first communicating pipe, the liquid volume of the culture medium remaining in the receiving tank can be set as the predetermined liquid volume, so that the culture medium can be contained in the first culture tank up to the height of the connection position between the discharge pipe and the first communicating pipe. [Explanation of symbols]

[0115] 1...cultivation system, 5...control section, 24a...culture tank (first culture tank), 24b...culture tank (second culture tank), 28a...bottom (first bottom), 28b...bottom (second bottom), 51...discharge pipe, 52...drive section, 53a...communicating pipe (first communicating pipe), 53b...communicating pipe (second communicating pipe), 54...main body section, 55...extension section, 56...opening (first opening), 57...opening (second opening), 58a...one end (first end), 58b...one end (third end), 59a...other end (second end), 59b...other end (fourth end), 61...receiving tank, 62...liquid level meter (liquid volume measuring section), 66...pump (supply section), C...culture liquid, D1, D2, H1, H2...distance, P...photosynthetic microorganism.

Claims

1. A first culture tank containing a culture solution for culturing photosynthetic microorganisms; a discharge pipe extending in a vertical direction and movable up and down in the vertical direction, the discharge pipe having a first opening at a lower end thereof, the discharge pipe discharging the culture medium from the first opening; A first communication pipe that communicates the first culture tank and the discharge pipe and has flexibility; Equipped with Culture system.

2. The first culture tank has a bottom, The first communication pipe is a first end connected to the bottom; and a second end connected to the exhaust pipe. The culture system according to claim 1 .

3. A second culture tank containing the culture solution for culturing the photosynthetic microorganism; Further comprising a second communicating pipe that communicates the second culture tank and the discharge pipe and has flexibility; The culture system according to claim 1 .

4. The first culture tank has a first bottom, The first communication pipe is a first end connected to the first bottom; and a second end connected to the exhaust pipe. The second culture tank has a second bottom, The second communication pipe is a third end connected to the second bottom; a fourth end connected to the exhaust pipe; The first culture tank and the second culture tank are arranged in the vertical direction, The distance between the first end and the third end is equal to the distance between the second end and the fourth end. The culture system according to claim 3 .

5. The exhaust pipe is a main body portion including the first opening, extending in the vertical direction, and connected to the first communicating pipe; a second opening provided on the opposite side to the first opening; and an extension extending from an upper end of the main body. The culture system according to any one of claims 1 to 4.

6. The second opening faces downward. The culture system according to claim 5 .

7. A receiving tank that stores the culture solution discharged from the first opening of the discharge pipe; A liquid volume measuring unit that measures the volume of the culture liquid stored in the receiving tank; A supply unit that supplies the culture solution stored in the receiving tank to the first culture tank; A drive unit that raises and lowers the discharge pipe; A control unit that controls the supply unit and the drive unit, The control unit is By controlling the drive unit, the discharge pipe is moved to a predetermined height; With the discharge pipe positioned at the predetermined height, the supply unit is controlled to start supplying the culture medium; determining whether or not a condition is satisfied that a predetermined time has elapsed since the start of the supply of the culture medium and that the amount of the medium is equal to or less than a predetermined amount of the medium; If it is determined that the condition is not satisfied, restarting the supply of the culture medium; If it is determined that the condition is satisfied, the supply of the culture medium is stopped. The culture system according to any one of claims 1 to 4.

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