Algae growth promotion device

Abstract

To provide algae growth promotion equipment in which trouble due to electrodes for electric stimulation to algae is suppressed, and furthermore which performs algae growth promotion by the electric stimulation.SOLUTION: A bioreactor 10 has a housing space 101 that houses liquid including prescribed algae. A vector potential coil of a vector potential coil device 1 is disposed in at least one of the housing space 101 and outside of the bioreactor 10. An electric power source device 2 allows an alternating current to pass through the vector potential coil, allows a vector potential corresponding to the alternating current to generate in the housing space 101, and applies an electric field generated on the basis of the vector potential, to liquid, thereby electrically stimulating the algae.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an apparatus for promoting the growth of algae.

Background Art

[0002] In recent years, algal biomass has attracted attention as a biomass resource. A liquid containing a predetermined alga is stored in a bioreactor, cultured and grown in the bioreactor, and lipids, proteins, polysaccharides, etc. such as fuels are extracted from the algae obtained by the growth.

[0003] In order to obtain a large amount of algae in a short time, various growth promotion methods have been proposed. In one growth promotion method, a pulsed current is applied from an electrode to a medium containing the microalga Aurantiochytrium to increase the biomass amount (see, for example, Non-Patent Document 1).

[0004] On the other hand, a vector potential generator that generates a vector potential by passing an electric current through a vector potential coil around a solenoid coil has been developed (see, for example, Patent Document 1). Also, a vector potential detector that detects a vector potential by utilizing the fact that a voltage is induced by a time-varying vector potential has been developed (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0006]

Non-Patent Document 1

[0007] In the above-described method for promoting algae growth, electrodes must be brought into contact with the liquid containing the algae in order to conduct an electric current through it. Therefore, (a) metal ions originating from the electrodes may leach into the liquid, potentially adversely affecting algal growth, and (b) the electrodes may corrode. Furthermore, using electrodes that do not cause these problems would increase the cost of the electrodes, which is undesirable.

[0008] The present invention has been made in view of the above, and aims to provide an algae growth promoting device that promotes the growth of algae by electrical stimulation while suppressing the occurrence of malfunctions caused by electrodes for electrical stimulation of algae. [Means for solving the problem]

[0009] The algae growth promoting device according to the present invention comprises a bioreactor having a containment space for containing a liquid containing a predetermined algae, and at least one of the containment space of the bioreactor and the outside of it. multiple A vector potential coil and, Those multiple The system includes a power supply that conducts alternating current through a vector potential coil, generates a vector potential corresponding to the alternating current in the containment space, and applies the electric field generated based on the vector potential to the liquid to provide electrical stimulation to the algae. The aforementioned vector potential coils are arranged along the axial direction of the bioreactor. Each of these vector potential coils is a solenoid coil extending along a curved coil axis, with an opening in the circumferential direction, and its coil axis does not make more than one turn. The aforementioned algae are photosynthetic algae, and the bioreactor transmits culture light from the outside into the containment space, with the aforementioned vector potential coils positioned on the outside of the bioreactor opposite to the side where the culture light enters the containment space. [Effects of the Invention]

[0010] According to the present invention, an algae growth promoting device is obtained that promotes the growth of algae by electrical stimulation while suppressing the occurrence of malfunctions caused by electrodes for electrical stimulation of algae. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a block diagram showing the configuration of the algae growth promoting device 10 according to an embodiment of the present invention. [Figure 2] Figure 2 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 1. [Figure 3] Figure 3 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 2. [Figure 4] Figure 4 shows an example of a vector potential coil device 1 in Embodiment 3. [Figure 5] Figure 5 shows an example (partial) of the vector potential coil device 1 in Embodiment 4. [Figure 6] Figure 6 shows an example of the bioreactor 10 and vector potential coil device 1 in Embodiment 5. [Figure 7] Figure 7 is a top view showing an example of a vector potential coil device 1 in Embodiment 6. [Figure 8] Figure 8 is a side view showing an example of a vector potential coil device 1 in Embodiment 6. [Figure 9] Figure 9 is a top view showing an example of a vector potential coil device 1 in Embodiment 7. [Figure 10] Figure 10 is a top view showing an example of a vector potential coil device 1 in Embodiment 8. [Figure 11] Figure 11 is a top view showing an example of a vector potential coil device 1 in Embodiment 9. [Figure 12] Figure 12 is a top view showing an example of a vector potential coil device 1 in Embodiment 10. [Figure 13] FIG. 13 is a top view showing an example of the vector potential coil device 1 in Embodiment 11. [Figure 14] FIG. 14 is a side view showing an example of the vector potential coil device 1 in Embodiment 12. [Figure 15] FIG. 15 is a top view showing an example of the vector potential coil device 1 in Embodiment 12. [Figure 16] FIG. 16 is a view showing an example of the bioreactor 10 and the vector potential coil device 1 in Embodiment 13. [Figure 17] FIG. 17 is a view showing an example of the bioreactor 10 and the vector potential coil device 1 in Embodiment 14.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0013] Embodiment 1.

[0014] FIG. 1 is a block diagram showing the configuration of an algae growth promoting device according to an embodiment of the present invention.

[0015] The algae growth promoting device shown in FIG. 1 includes a bioreactor 10, a vector potential coil device 1, a power supply device 2, and a controller 3.

[0016] The bioreactor 10 is a component having a containment space for containing a liquid containing a predetermined type of algae. In Embodiment 1, the bioreactor 10 is a pipe-shaped component. However, the bioreactor 10 may also be a container-shaped component, a raceway-type culture tank, etc. The predetermined type of algae mentioned above is an algae (here, a single-celled microalgae) that produces or takes up lipids, proteins, polysaccharides, etc., such as fuel, and may be photosynthetic or non-photosynthetic. For example, Aurantiochytrium, Botryococcus, Pseudocholcystis, Ikadamo, Nannochloropsis, etc., can be used as the predetermined type of algae. The liquid mentioned above is a conductive liquid culture medium (e.g., water containing electrolytes, salt water, brackish water, seawater, etc.) to which the above-mentioned algae are added. In this case, the bioreactor 10 is a non-metallic component (e.g., made of resin). Furthermore, if the bioreactor 10 is made of metal, for example, the parts that come into contact with the aforementioned liquid (such as the inner wall) may be covered with resin or the like to prevent the liquid from coming into contact with the metal.

[0017] When photosynthetic algae are used, the bioreactor 10 is made of (at least partially) light-transmitting material (e.g., a transparent resin material). When non-photosynthetic algae are used, the bioreactor 10 may be made of either light-transmitting or non-light-transmitting material (e.g., a metal material).

[0018] Figure 2 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 1.

[0019] For example, as shown in Figure 2, the vector potential coil device 1 includes a vector potential coil (hereinafter also referred to as a VP coil) 11 located in the housing space 101 of the bioreactor 10 and at least one of the outer sides (here, the outer side). In Embodiment 1, for example, as shown in Figure 2, the VP coil 11 is a solenoid coil that revolves along a helical coil axis. Here, the bioreactor 10 is a cylindrical member, and the VP coil 11 has a helical coil axis that revolves in a circular manner.

[0020] Furthermore, the power supply unit 2 generates an alternating current based on power from a commercial power source or a battery (primary or secondary battery), conducts this alternating current to the VP coil 11, generates a time-varying vector potential in the aforementioned containment space 101 corresponding to the alternating current, and applies the electric field generated based on this vector potential to the aforementioned liquid to provide electrical stimulation to the aforementioned algae and promote their growth. Specifically, if the aforementioned liquid is conductive, an alternating electric field is applied to the liquid, and an alternating current corresponding to the voltage of the electric field conducts through the liquid. As a result, both electrical stimulation from the electric field and electrical stimulation from the current are applied to the aforementioned algae. On the other hand, if the aforementioned liquid is not conductive, an alternating electric field is applied to the liquid, but the aforementioned alternating current does not conduct.

[0021] amplitude I m When an alternating current, which is a sine wave, is passed through the VP coil 11, an alternating voltage V2, as shown in the following equation, is generated in the containment space 101 in accordance with the time change of the vector potential generated by the alternating current, and an alternating current corresponding to that alternating voltage conducts through the liquid in the containment space 101.

[0022]

number

[0023] Here, μ0 is the vacuum permeability, n is the number of turns per unit length of the solenoid in the VP coil 11, N1 is the number of turns per unit length of the helical VP coil 11, S is the cross-sectional area of ​​the solenoid in the VP coil 11, ω is the angular frequency of the alternating current, a is the cross-sectional radius of the helical VP coil 11, L is the length of the VP coil 11 (distance between both ends), and t is time.

[0024] Furthermore, the controller 3 is a computer or the like that executes a control program, and controls the power supply 2 to conduct an alternating current of a predetermined frequency to the VP coil 11 at predetermined timings (such as constantly or at predetermined time intervals). For example, the controller 3 may conduct a pulse-like alternating current at a high frequency for a short time to the power supply 2.

[0025] Next, we will explain the operation of the algae growth promotion device described above.

[0026] Controller 3 controls a fluid control device (such as a pump or valve) not shown to introduce the liquid containing the aforementioned algae into the pipe-shaped bioreactor 10, and then controls the power supply unit 2 to supply alternating current to the VP coil 11.

[0027] At that time, the power supply unit 2 generates an alternating current with a predetermined waveform (amplitude and frequency) at a predetermined timing and supplies it to the VP coil 11.

[0028] A magnetic field is generated along the coil axis by the current flowing through the VP coil 11, and a vector potential is generated parallel to this current. The strength of the vector potential in the direction of the curve of the VP coil 11 (i.e., the containment space 101) is greater than the vector potential in the direction of the curve of the VP coil 11.

[0029] Then, in the containment space 101, the vector potential alters, and as described above, an alternating voltage is generated in accordance with its temporal change. An alternating current corresponding to this alternating voltage is conducted to the liquid in the containment space 101, and an electrical stimulus is applied to the algae in the containment space 101. This promotes the growth of the algae in the containment space 101.

[0030] After a predetermined time has elapsed, the controller 3 controls a fluid control device (such as a pump or valve) (not shown) to discharge the liquid containing the grown algae from the bioreactor 10. Then, using existing methods, biomass resources such as lipids, proteins, and polysaccharides are extracted from the grown algae in the discharged liquid.

[0031] As described above, according to the above embodiment, the bioreactor 10 has a containment space 101 that contains a liquid containing a predetermined algae. The VP coil 11 is located in at least one of the containment space 101 and the outside of the bioreactor 10. The power supply unit 2 conducts an alternating current to the VP coil 11, generates a vector potential corresponding to the alternating current in the containment space 101, and applies an electric field generated based on the vector potential to the liquid to provide electrical stimulation to the algae.

[0032] This allows electrical stimulation to be applied to algae without contacting the liquid containing the algae with electrodes. Therefore, it is possible to promote the growth of algae through electrical stimulation while suppressing the occurrence of problems caused by electrodes used for electrical stimulation of algae.

[0033] Embodiment 2.

[0034] Figure 3 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 2.

[0035] In Embodiment 2, for example, as shown in Figure 3, the bioreactor 10 is a container-shaped member. Here, the bioreactor 10 is a cylindrical container. The bioreactor 10 shown in Figure 3 includes a pipe 10a for introducing the liquid to which the algae have been added, a pipe 10b for discharging the liquid to which the algae have been added, a stirring device 10c (stirring blades, motor, etc.), and a sensor 10d such as a temperature sensor.

[0036] In Embodiment 2, the above-mentioned liquid is stored in the bioreactor 10, and a VP coil 11 similar to that in Embodiment 1 is positioned outside the position (height) where the above-mentioned liquid is stored.

[0037] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 2 are the same as those of any of the other embodiments, so their description will be omitted.

[0038] Embodiment 3.

[0039] Figure 4 shows an example of a vector potential coil device 1 in Embodiment 3.

[0040] In Embodiment 3, for example, as shown in Figure 4, the vector potential coil device 1 further includes a ferromagnetic member 11A that extends along the coil axis within the solenoid coil constituting the VP coil 11, in addition to the VP coil 11.

[0041] This ferromagnetic member 11A is made of a conductive material such as permalloy. One end of the VP coil 11 and one end 11A1 (first connection point) of the ferromagnetic member 11A are electrically connected to each other, and the power supply device 2 applies a voltage to the other end of the VP coil 11 and the other end 11A2 (second connection point) of the ferromagnetic member 11A to conduct alternating current through the VP coil 11.

[0042] In this way, the ferromagnetic member 11A becomes the path for the alternating current described above, and two terminals are arranged on either end of the VP coil 11. As a result, the wiring from the power supply unit 2 to the VP coil 11 and the ferromagnetic member 11A is simplified, and the area enclosed by the path through which the current flows is relatively small, thereby suppressing unwanted magnetic fields generated by the current flowing through this wiring.

[0043] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 3 are the same as those of any of the other embodiments, so their description will be omitted.

[0044] Embodiment 4.

[0045] Figure 5 shows an example (partial) of the vector potential coil device 1 in Embodiment 4.

[0046] In Embodiment 4, as shown in Figure 5, for example, the VP coil 11 comprises an inner solenoid coil 11-1 and an outer solenoid coil 11-2, each extending along the same coil axis and having different coil diameters. One end of the inner solenoid coil 11-1 and one end of the outer solenoid coil 11-2 are electrically connected to each other. The inner solenoid coil 11-1 and the outer solenoid coil 11-2 each function as a single VP coil. Therefore, the VP coil 11 of Embodiment 4 is electrically configured as two VP coils connected in series in phase. The power supply unit 2 applies voltage to the other end of the inner solenoid coil 11-1 and the other end of the outer solenoid coil 11-2 to conduct alternating current through the vector potential coil. As a result, the vector potential from the inner solenoid coil 11-1 and the vector potential from the outer solenoid coil 11-2 are generated in the same direction.

[0047] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 4 are the same as those of any of the other embodiments, so their description will be omitted.

[0048] Embodiment 5.

[0049] Figure 6 shows an example of the bioreactor 10 and vector potential coil device 1 in Embodiment 5.

[0050] In Embodiment 5, for example as shown in Figure 6, the vector potential coil device 1 (such as a VP coil 11) is placed in the housing space 101 of the bioreactor 10. Within the internal space of the VP coil, an electric field generated based on the aforementioned vector potential is applied to the aforementioned liquid. Furthermore, if the aforementioned liquid is conductive, for example as shown in Figure 6, an alternating current I(t) conducts circumferentially between the internal space of the VP coil 11 and the outside of the VP coil 11. Note that, here, the same vector potential coil device 1 as in Embodiment 3 is placed in the housing space 101, but the same vector potential coil device 1 as in other embodiments may also be placed in the housing space 101.

[0051] When the vector potential coil device 1 is placed in the containment space 101 of the bioreactor 10, the vector potential coil device 1 (VP coil 11 and ferromagnetic member 11A, etc.) is covered to prevent the conductors of the VP coil 11 (i.e., metal parts) from coming into contact with the liquid in the containment space 101. In addition, the power supply unit 2 and controller 3 are located outside the bioreactor 10, and the wiring from the power supply unit 2 to the VP coil 11 is laid through the walls of the bioreactor 10 to prevent liquid leakage from the bioreactor 10.

[0052] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 5 are the same as those of any of the other embodiments, so their description will be omitted.

[0053] Embodiment 6.

[0054] Figure 7 is a top view showing an example of the vector potential coil device 1 in Embodiment 6. Figure 8 is a side view showing an example of the vector potential coil device 1 in Embodiment 6.

[0055] In the algae growth promoting device according to Embodiment 6, the algae are photosynthetic algae, and the bioreactor 10 transmits external culture light into the containment space 101.

[0056] In Embodiment 6, for example, as shown in Figures 7 and 8, the VP coil 12 is located both inside and outside the containment space 101 of the bioreactor 10. Specifically, the VP coil 12 is located outside the bioreactor 10, on the side opposite to the side where culture light is incident into the containment space 101.

[0057] Furthermore, in Embodiment 6, the VP coil 12 is a solenoid coil that extends along a curved coil axis and has an opening in the circumferential direction. In other words, the coil axis of the VP coil 12 does not extend more than one full turn. Since the VP coil 12 is not present in the opening, the VP coil 12 does not obstruct the incidence of culture light (sunlight, artificial light, etc.) into the containment space 101.

[0058] For example, the coil axis of the VP coil 12 is arc-shaped, and the angle (central angle) from one end to the other of the VP coil 12 (its coil axis) as viewed from the center of the circle containing the coil axis (i.e., the arc) (here, the central axis of the housing space 101) is less than 360 degrees. This forms the aforementioned opening. For example, the central angle may be 180 degrees, or less than 180 degrees. However, a larger central angle is preferable because the intensity of the vector potential in the direction of the curve increases as the central angle increases. This central angle is any angle greater than 0 degrees and less than 360 degrees, and furthermore, (a) it may be any angle greater than 0 degrees and less than or equal to 180 degrees, (b) it may be any angle greater than 0 degrees and less than or equal to 90 degrees, (c) it may be any angle greater than 0 degrees and less than or equal to 45 degrees, or (d) it may be any angle greater than 0.5 degrees and less than 360 degrees, furthermore, (e) it may be any angle greater than 0.5 degrees and less than or equal to 180 degrees, (f) it may be any angle greater than 0.5 degrees and less than or equal to 90 degrees, (e) it may be any angle greater than 0.5 degrees and less than or equal to 45 degrees, (f) it may be any angle greater than 0.5 degrees and less than or equal to 25 degrees, or (g) it may be 2 degrees or more It may be any angle less than 360 degrees, and furthermore, (h) any angle between 2 degrees and 180 degrees, (i) any angle between 2 degrees and 90 degrees, (j) any angle between 2 degrees and 45 degrees, (k) any angle between 2 degrees and 25 degrees, or (l) any angle between 5 degrees and less than 360 degrees, furthermore, (m) any angle between 5 degrees and 180 degrees, (n) any angle between 5 degrees and 90 degrees, (o) any angle between 5 degrees and 45 degrees, or (p) any angle between 5 degrees and 25 degrees.

[0059] The vector potential generated by the current flowing through the VP coil 12 weakens as you move away from the current. However, as mentioned above, the VP coil 12 (or its coil axis) is curved, so in the direction of the curve (or the center of curvature in the case of a circular arc), the vector potentials generated by the currents at each position in the VP coil 12 overlap, resulting in a greater strength.

[0060] Furthermore, the algae growth promoting device according to Embodiment 6 further includes a reflective layer 21 between the bioreactor 10 and the VP coil 12 that reflects culture light into the containment space 101. This increases the amount of culture light irradiated onto the algae in the liquid. For example, the reflective layer 21 is provided over all or part of the angular range of the central angle described above. For example, the reflective layer 21 is a metal film formed on the surface of the bioreactor 10 by aluminum vapor deposition or the like, and is a component with a shape substantially identical to the surface of the bioreactor 10. Even if the reflective layer 21 is a metal film, the vector potential is not shielded by the metal, so a vector potential is generated in the containment space 101 by the alternating current of the VP coil 12.

[0061] Furthermore, the algae growth promoting device according to Embodiment 6 is equipped with a plurality of identical VP coils 12. These VP coils 12 are arranged along the axial direction of the pipe-shaped bioreactor 10.

[0062] The power supply unit 2 conducts alternating current through multiple VP coils 12, generating a vector potential corresponding to the alternating current in the containment space 101. The alternating current corresponding to the voltage generated based on the vector potential is then conducted through the liquid in the containment space 101, providing electrical stimulation to the algae in the liquid. The VP coils 12 are electrically connected to each other in series or parallel, and each generates a vector potential in the same direction at any given time.

[0063] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 6 are the same as those of any of the other embodiments, so their description will be omitted.

[0064] Embodiment 7.

[0065] Figure 9 is a top view showing an example of a vector potential coil device 1 in Embodiment 7.

[0066] In Embodiment 7, for example as shown in Figure 9, the vector potential coil device 1 further includes a ferromagnetic member 12A extending along the coil axis within the solenoid coil, which is the VP coil 12. The ferromagnetic member 12A is formed of a conductive material such as permalloy. One end of the VP coil 12 and one end 12A1 (first connection point) of the ferromagnetic member 12A are electrically connected to each other. The power supply device 2 applies a voltage to the other end of the VP coil 12 and the other end 12A2 (second connection point) of the ferromagnetic member 12A to conduct an alternating current through the VP coil 12.

[0067] As the vector potential is amplified according to the effective permeability of the ferromagnetic member 12A, the intensity of the vector potential increases in the inward direction of the curvature (or at the center of curvature in the case of an arc).

[0068] Since the coil axis of the VP coil 12 does not make more than one turn, the distance between the two ends of the VP coil 12 is large. However, the ferromagnetic material 12A acts as the current path, and two terminals are located on either end of the VP coil 12. This simplifies the installation of wiring from the power supply unit 2 to the VP coil 12 and the ferromagnetic material 12A. Furthermore, the area enclosed by the current path is relatively small, suppressing unwanted magnetic fields generated by the current flowing through this wiring.

[0069] The other configurations and operations of the algae growth promoting device according to Embodiment 7 are the same as those of Embodiment 6, so their description will be omitted.

[0070] Embodiment 8.

[0071] Figure 10 is a top view showing an example of a vector potential coil device 1 in Embodiment 8.

[0072] In Embodiment 8, for example as shown in Figure 10, the vector potential coil device 1 further includes a ferromagnetic member 12B extending along the coil axis within the solenoid coil as the VP coil 12. The ferromagnetic member 12B is conductive, and one end of the VP coil 12 and the connection point 12B1 of the ferromagnetic member 12B (a location on the one end side of the VP coil 12, the first connection point) are electrically connected to each other. The power supply device 2 applies a voltage to the other end of the VP coil 12 and the connection point 12B2 of the ferromagnetic member 12B (a location on the other end side of the VP coil 12, the second connection point) to conduct an alternating current through the VP coil 12.

[0073] Furthermore, the ferromagnetic member 12B is curved outward (in the direction of the outward curve) from the connection points 12B1 and 12B2, and the ferromagnetic member 12B forms a closed magnetic path via the gap G. The gap G prevents current from conducting in the outer part of the curve of the VP coil 12.

[0074] Furthermore, in order to minimize the effects of magnetic flux leakage and the reduction in permeability due to bending, it is preferable that the transition portion between the inner and outer parts of the ferromagnetic member 12B be a continuously smooth curve without any sharp bends. In addition, the ferromagnetic member 11B may be formed by connecting multiple members.

[0075] The other configurations and operations of the algae growth promoting device according to Embodiment 8 are the same as those of Embodiment 6, so their description will be omitted.

[0076] Embodiment 9.

[0077] Figure 11 is a top view showing an example of a vector potential coil device 1 in Embodiment 9.

[0078] In Embodiment 9, for example, as shown in Figure 11, the VP coil 12 comprises an inner solenoid coil 12-1 and an outer solenoid coil 12-2, each extending along the same coil axis and having different coil diameters. One end of the inner solenoid coil 12-1 and one end of the outer solenoid coil 12-2 are electrically connected to each other. The power supply unit 2 applies voltage to the other end of the inner solenoid coil 12-1 and the other end of the outer solenoid coil 12-2 to conduct alternating current through the VP coil 12.

[0079] The inner solenoid coil 12-1 and the outer solenoid coil 12-2 each function as a single VP coil. Therefore, electrically, the VP coil 12 of Embodiment 9 is configured as two VP coils connected in series in phase. The power supply unit 2 applies voltage to the other end of the inner solenoid coil 12-1 and the other end of the outer solenoid coil 12-2 to conduct alternating current through the vector potential coil. As a result, the vector potential from the inner solenoid coil 12-1 and the vector potential from the outer solenoid coil 12-2 are generated in the same direction.

[0080] The other configurations and operations of the algae growth promoting device according to Embodiment 9 are the same as those of Embodiment 6, so their description will be omitted.

[0081] Embodiment 10.

[0082] Figure 12 is a top view showing an example of a vector potential coil device 1 in Embodiment 10.

[0083] In Embodiment 10, for example as shown in Figure 12, the vector potential coil device 1 further includes a ferromagnetic member 12C extending along the coil axes of the inner solenoid coil 12-1 and the outer solenoid coil 12-2, which constitute the VP coil 12. The ferromagnetic member 12C is not electrically connected to the inner solenoid coil 12-1 and the outer solenoid coil 12-2.

[0084] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 10 are the same as those of Embodiment 9, so their description will be omitted.

[0085] Embodiment 11.

[0086] Figure 13 is a top view showing an example of a vector potential coil device 1 in Embodiment 11.

[0087] In Embodiment 11, for example as shown in Figure 13, the vector potential coil device 1 includes a ferromagnetic member 12D extending along the coil axis of the inner solenoid coil 12-1 and the outer solenoid coil 12-2, which are VP coils 12.

[0088] Furthermore, the ferromagnetic member 12D extends outward from both ends of the VP coil 12 in a curved manner, forming a closed magnetic path. Note that the ferromagnetic member 12D is not electrically connected to the inner solenoid coil 12-1 and the outer solenoid coil 12-2. The ferromagnetic member 12D does not need to be conductive, and no gap is provided. In Embodiment 11, the alternating current conducts through the inner solenoid coil 12-1 and the outer solenoid coil 12-2 but not through the ferromagnetic member 12D, so the ferromagnetic member 12D does not require conductivity or a gap.

[0089] The other configurations and operations of the algae growth promoting device according to Embodiment 11 are the same as those of Embodiment 9, so their description will be omitted.

[0090] Embodiment 12.

[0091] Figure 14 is a side view showing an example of the vector potential coil device 1 in Embodiment 12. Figure 15 is a top view showing an example of the vector potential coil device 1 in Embodiment 12.

[0092] The algae growth promoting device according to Embodiment 12 comprises a plurality of identical VP coils 13, as shown in Figures 14 and 15, for example. In Embodiment 12, each VP coil 13 is an identical solenoid coil with a linear coil axis. These VP coils 13 are arranged along the circumferential direction of the pipe-shaped bioreactor 10.

[0093] The power supply unit 2 conducts alternating current through multiple VP coils 13, generating a vector potential corresponding to the alternating current in the containment space 101. The alternating current corresponding to the voltage generated based on the vector potential is then conducted through the liquid in the containment space 101, providing electrical stimulation to the algae in the liquid. The VP coils 13 are electrically connected to each other in series or parallel, and each generates a vector potential in the same direction at any given time.

[0094] Multiple VP coils 13 are arranged (in this case, at equal angular intervals) within an angular range of a predetermined central angle θ from the center of the containment space 101. At the intermediate position between two VP coils 13, the vector potentials of the two VP coils 13 cancel each other out, so this central angle θ is, for example, any angle less than 180 degrees.

[0095] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 12 are the same as those of any of the other embodiments, so their description will be omitted.

[0096] Embodiment 13.

[0097] Figure 16 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 13.

[0098] In Embodiment 13, for example, as shown in Figure 16, the VP coil 11 is positioned outside the bioreactor 10 (main fluid channel). Furthermore, the bioreactor 10 includes a secondary fluid channel 10A that connects the upstream and downstream sides of the VP coil 11's position, separate from the main fluid channel. Therefore, the alternating current generated by the VP coil 11 conducts through the liquid in the secondary fluid channel 10A, providing electrical stimulation to the algae. In other words, the alternating current I(t) is conducted circulatingly through the liquids in the main and secondary fluid channels.

[0099] Furthermore, as shown in Figure 16, for example, a non-metallic (e.g., made of resin) porous filter 10B may be provided in the sub-liquid channel 10A. In that case, the porous filter 10B will not allow the algae to pass through, but it will allow the liquid to pass through. Therefore, even with the porous filter 10B, the AC current I(t) will conduct through the sub-liquid channel 10A. Alternatively, a similar VP coil 11 may be installed in the sub-liquid channel 10A. In that case, the VP coil 11 in the sub-liquid channel 10A will be installed so as to generate an AC current with the same direction as the AC current I(t) generated by the VP coil 11 in the main liquid channel.

[0100] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 13 are the same as those of any of the other embodiments, so their description will be omitted.

[0101] Embodiment 14.

[0102] Figure 17 shows an example of a bioreactor 10 and a vector potential coil device 1 in Embodiment 14.

[0103] In Embodiment 14, as shown in Figure 17 for example, the bioreactor 10 comprises a culture tank 41, a circulation pipe 42 connected to the culture tank 41 for circulating liquid, and a pump 43 provided in the circulation pipe 42, with the VP coil 11 installed in the circulation pipe 42. In Embodiment 14, the pump 43 circulates the aforementioned liquid through the culture tank 41 and the circulation pipe 42 at a predetermined flow rate (flow rate), and the VP coil 11 provides the aforementioned electrical stimulation to the algae in the liquid within the circulation pipe 42. In this embodiment, the parts of the pump 43 that come into contact with the aforementioned liquid are covered with resin or other materials, or non-metallic materials such as resin are used to prevent the liquid from coming into contact with metal.

[0104] Here, the aforementioned liquid is conductive, conductivity is ensured from the liquid in the intake port to the liquid in the outlet port of the pump 43, and when the aforementioned liquid is contained in the culture tank 41 such that the liquid level in the culture tank 41 is above a predetermined reference liquid level, the aforementioned alternating current conducts through the liquid in the culture tank 41 and the circulation piping 42, as well as the pump 43. Here, the reference liquid level is set to the height of the outlet port 42a of the circulation piping 42.

[0105] Even if the liquid level in the culture tank 41 is below a predetermined standard liquid level, if the liquid is circulating at a sufficient flow rate, the liquid discharged from the outlet 42a will continue to flow up to the liquid level in the culture tank 41. In this case, the aforementioned alternating current will conduct through the liquid in the culture tank 41 and the circulation piping 42, as well as the pump 43. However, if the liquid is not circulating at a sufficient flow rate, the liquid discharged from the outlet 42a will fall in droplet form to the liquid level in the culture tank 41. In this case, the aforementioned alternating current will not conduct through the liquid in the culture tank 41 and the circulation piping 42, nor through the pump 43. In this case, although the aforementioned alternating current does not conduct, the aforementioned electric field is applied to the circulating liquid. Therefore, the liquid level in the culture tank 41 and the circulation flow rate of the liquid by the pump 43 may be adjusted to select whether or not the aforementioned alternating current conducts.

[0106] Furthermore, the other configurations and operations of the algae growth promoting device according to Embodiment 14 are the same as those of any of the other embodiments, so their description will be omitted.

[0107] Furthermore, various changes and modifications to the embodiments described above will be obvious to those skilled in the art. Such changes and modifications may be made without deviating from the spirit and scope of the subject matter and without diminishing the intended advantages. In other words, such changes and modifications are intended to be included in the claims.

[0108] For example, in any of the embodiments 1 to 14 described above, the bioreactor 10 may be a raceway-type culture tank, in which case the VP coils 11, 12, 13 described above are arranged in the containment space (the space in which the liquid containing algae is contained), or the VP coils 11, 12, 13 are arranged on the bottom and / or outside the sides of the culture tank.

[0109] Furthermore, the bioreactor 10 in any of the embodiments 1 to 14 described above is not limited to those exemplified, and may take any of the various forms, such as a pipe-shaped bioreactor, a container-shaped bioreactor, or a raceway-type bioreactor.

[0110] Furthermore, in embodiments 4, 9 to 11 described above, the VP coil 12 has a two-layer structure in the radial direction, consisting of an inner solenoid coil 12-1 and an outer solenoid coil 12-2. However, the number of layers may be four or more, as long as the number of layers is even. In that case, one end of a solenoid coil 12-i is connected to the solenoid coil 12-(i+1) of the next layer so that all the solenoid coils 12-i of each layer are electrically connected in series.

[0111] Furthermore, in embodiments 1 to 14 described above, the VP coils 11, 12, and 13 are arranged only in the containment space 101 of the bioreactor 10 and on the outside, but the VP coil 11 may be arranged in both the containment space 101 and on the outside of the bioreactor 10.

[0112] Furthermore, in embodiments 1 to 4 and 6 to 14 described above, instead of the vector potential coil device 1 (VP coils 11, 12, 13) being located outside the bioreactor 10, the vector potential coil device 1 may be located in the housing space 101 of the bioreactor 10.

[0113] In any of the embodiments 1 to 14 described above, if the liquid to which the algae are added is conductive, an alternating current is applied to the algae as an electrical stimulus in addition to the alternating electric field generated by the vector potential as described above. If the liquid to which the algae are added is not conductive, an alternating electric field generated by the vector potential is applied to the algae as an electrical stimulus even if no current flows through the liquid. [Industrial applicability]

[0114] The present invention can be applied, for example, to promoting the growth of algae. [Explanation of symbols]

[0115] 1. Vector potential coil device 2 Power supply 3 Controllers 10 Bioreactors 10A auxiliary liquid path 11,12,13 Vector potential coil 11-1, 12-1 Inner solenoid coil 11-2, 12-2 Outer solenoid coil 11A,11B,12A,12B,12C,12D Ferromagnetic materials 21 Reflective layer 41 Culture tank 42 Circulation piping 43 pumps 101 Containment Space

Claims

1. A bioreactor having a containment space for containing a liquid containing a specified type of algae, A plurality of vector potential coils are arranged in at least one of the containment space and the outside of the bioreactor, A power supply device that conducts alternating current through the plurality of vector potential coils, generates a vector potential corresponding to the alternating current in the containment space, and applies the electric field generated based on the vector potential to the liquid to provide electrical stimulation to the algae, Equipped with, The plurality of vector potential coils are arranged along the axial direction of the bioreactor, Each of the aforementioned vector potential coils is a solenoid coil extending along a curved coil axis, having an opening in the circumferential direction, and the coil axis does not make more than one full turn. The aforementioned algae are photosynthetic algae, The bioreactor transmits external culture light into the containment space. The plurality of vector potential coils are positioned outside the bioreactor on the side opposite to the side where the culture light is incident into the containment space. An algae growth promoting device characterized by the following.

2. The solenoid coil further comprises a ferromagnetic member extending along the coil axis, The ferromagnetic member has conductivity, One end of the vector potential coil and the first connection point of the ferromagnetic member are electrically connected to each other. The power supply device applies a voltage to the other end of the vector potential coil and the second connection point of the ferromagnetic member to conduct current through the vector potential coil. The algae growth promoting device according to claim 1, characterized by the following:

3. The vector potential coil comprises an inner solenoid coil and an outer solenoid coil, each extending along the same coil axis. One end of the inner solenoid coil and one end of the outer solenoid coil are electrically connected to each other. The power supply device applies a voltage to the other end of the inner solenoid coil and the other end of the outer solenoid coil to conduct current in the vector potential coil. The algae growth promoting device according to claim 1, characterized by the following:

4. The algae growth promoting apparatus according to claim 1, further comprising a reflective layer that reflects the culture light between the bioreactor and the vector potential coil, wherein the reflective layer has a metal film.

5. The aforementioned liquid is electrically conductive, The power supply device provides electrical stimulation to the algae by conducting an alternating current corresponding to the voltage generated based on the vector potential through the liquid. The algae growth promoting device according to claim 1, characterized by the following:

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