JP4079877B2 - Microalgae culture apparatus and microalgae culture method - Google Patents

Description

<Technical field>
The present invention relates to a closed-type microalgae culture apparatus and a microalgae culture method for culturing microalgae that are photosynthetic organisms.
<Background technology>
Microalgae that are photosynthetic organisms are cultivated for aquaculture feed, etc., because they absorb carbon dioxide and produce useful components such as vitamins, amino acids, pigments, proteins, polysaccharides, and fatty acids by photosynthesis. . In addition, this type of microalgae is also used as a means for treating carbon dioxide, which is one of the causes of global warming, and recently, a culture apparatus for culturing this in large quantities has been studied.
By the way, the culture apparatus is for culturing microalgae in a culture solution, and the light necessary for photosynthesis mainly uses sunlight, and carbon dioxide is air or a mixed gas of carbon dioxide and air. Supply by blowing into.
Thus, in order to efficiently cultivate microalgae using solar energy efficiently in the culture device,
(1) Large amount of light received
(2) Thoroughly stir the culture solution, efficiently illuminate the microalgae, supply nutrients and carbon dioxide uniformly, and remove oxygen discharged from the microalgae
(3) Achieving agitation without stagnation of the culture solution, and reducing precipitation due to adhesion of microalgae to the wall and colonization.
Is required.
Conventionally, as a method for culturing microalgae, an open culture method using a culture pond, a raceway culture pond, or the like has been implemented. However, since this method does not allow sufficient agitation of the culture solution, light is only on the surface layer. Only microalgae that can be cultured under special conditions such as high pH and high salinity because the culture concentration is low, the culture concentration is low, and dust and dirt or airborne microorganisms cannot be prevented. There is a problem that the culture cannot be performed and the temperature of the culture solution is difficult to adjust.
Therefore, various types of closed-type culture devices for culturing microalgae in a culture vessel by putting visible light into the culture solution while injecting a gas containing carbon dioxide into the culture solution are proposed. Has been.
By the way, the capacity per installation area of the closed type culture apparatus is smaller than that of the open type culture method, and high concentration culture is required to increase high productivity.
However, in a closed type culture apparatus, light attenuates as it reaches from the light receiving wall side to the inside, so that algae that strikes the light and algae that do not strike are formed. Therefore, sufficient agitation of the culture solution in the apparatus is achieved. Without it, there is a problem that all algae cannot receive light fairly and high productivity cannot be achieved.
In a closed type culture device, microalgae adhere to the inner wall of the culture vessel, or microalgae form colonies in the culture vessel and precipitate, thereby blocking the transmission of light and significantly reducing the culture efficiency. There is a problem of doing. Furthermore, when microalgae settle in the culture vessel, it becomes a hotbed of bacteria, which also causes the culture solution to rot.
The present invention has been made in view of the above problems, and the intended treatment is that sufficient agitation of the culture solution can be realized to obtain high productivity, and adhesion of microalgae to the culture vessel wall surface and An object of the present invention is to provide a microalgae culture apparatus and a microalgae culture method that can prevent precipitation on the bottom surface of a culture vessel and maintain high culture efficiency over a long period of time.
<Disclosure of invention>
In order to achieve the above-mentioned object, the invention described in claim 1 includes a culture solution placed in a culture vessel having an opening at the top, and a gas containing carbon dioxide is blown into the culture solution while being visible. In the microalgae culture apparatus for cultivating microalgae in the culture vessel by making light incident, the culture vessel is formed into a double cylindrical shape consisting of a horizontally placed inner cylinder and an outer cylinder, and at least the outer cylinder is It is made of a transparent material that transmits visible light, and a gas blowing port for blowing a gas for forming a swirling flow of the culture solution into the culture vessel is opened at the lower part of the culture vessel.
The invention according to claim 2 is the invention according to claim 1, wherein the inner cylinder and the outer cylinder are constituted by a cylinder, an elliptic cylinder, or a long cylinder, and these inner cylinder and outer cylinder. Are arranged concentrically or eccentrically.
The invention according to claim 3 is characterized in that the culture solution is put into a culture vessel having an opening at the top, and visible light is incident while blowing a gas containing carbon dioxide into the culture solution. In the microalgae culture method for culturing microalgae in a culture vessel, the inner cylinder and the outer cylinder placed concentrically are formed into a double cylinder shape, and at least the outer cylinder is made of a transparent material that transmits visible light. A gas inlet opening in the lower part of the culture vessel is arranged on either the left or right of the vertical plane passing through the central axis of the inner cylinder and the outer cylinder, and the gas is blown from the gas inlet into the culture container. A swirling flow of the culture solution is formed.
The invention according to claim 4 is characterized in that the culture solution is put into a culture vessel having an opening at the top, and a visible ray is incident while blowing a gas containing carbon dioxide into the culture solution. In the microalgae cultivation method for culturing microalgae in a culture vessel, the inner cylinder and the outer cylinder, which are eccentrically placed horizontally, are formed into a double cylinder shape, and at least the outer cylinder is made of a transparent material that transmits visible light. The gas blowing port that opens at the lower part of the culture vessel is arranged on either the left or right side of the vertical plane that passes through the central axis of the inner cylinder, and the gas is blown from the gas blowing port so that the culture solution is introduced into the culture vessel. The swirl flow is formed.
The invention according to claim 5 is the invention according to claim 3 or 4, wherein the gas inlets are arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder of the culture vessel. In addition, the swirling direction of the culture solution in the culture vessel is alternately switched by alternately switching both gas blowing ports every predetermined time.
The invention according to claim 6 is the invention according to claim 3 or 4, wherein a plurality of gas injection ports are arranged in the longitudinal direction of the culture vessel, and A swirling flow of the culture solution that changes along the longitudinal direction of the culture vessel is formed in the culture vessel by sequentially blowing gas from the gas blowing port with a predetermined time difference.
The invention according to claim 7 is the invention according to claim 3 or 4, wherein the plurality of gas injection ports pass through the central axis of the inner cylinder along the longitudinal direction of the culture vessel. It arrange | positions alternately at right and left of a vertical surface, and forms the swirl | vortex flow of the culture solution from which a direction differs in a longitudinal direction alternately in a culture container by blowing in gas from each gas blowing port.
The invention according to claim 8 is the invention according to any one of claims 3 to 7, wherein water of temperature-controlled water is sprayed on the outer surface of the outer cylinder of the culture vessel, and the outer side of the outer cylinder. The temperature of the culture solution is controlled by passing the temperature-controlled water through the water passage formed in the above or the temperature-controlled water flowing into the inner cylinder.
Therefore, according to the invention described in claim 1, since the gas blowing port for blowing the gas for forming the swirling flow of the culture solution into the culture vessel is opened at the lower part in the culture vessel, The swirling flow forms a swirling flow of the culture solution in the culture vessel, and the culture solution is sufficiently agitated so that all the microalgae can receive light evenly, thereby achieving high productivity. . Also, the curved surface of the outer cylinder is caused by the mixed-phase turbulent flow during passage of bubbles in the culture solution, the turbulent boundary layer on the wall surface, and the geltler vortex caused by the flow of the culture solution along the curved wall of the double cylindrical culture vessel. A vortex is generated from the wall to the curved wall of the inner cylinder and from the curved wall of the inner cylinder to the curved wall of the outer cylinder, and the vortex stirs well without stagnation of the culture solution. There is no deposit or colony formation and precipitation, light transmission is not blocked by the microalgae, and the microalgae can efficiently and uniformly cultivate the microalgae to receive light efficiently, High culture efficiency can be maintained over a long period of time. Furthermore, since the culture vessel is composed of an inner cylinder and an outer cylinder with high pressure resistance, the plate thickness can be kept small, and the weight and cost of the apparatus can be reduced.
According to the invention described in claim 2, the culture vessel can be easily configured by arranging the inner cylinder and the outer cylinder made of a cylinder, an elliptic cylinder, or a long cylinder concentrically or eccentrically.
According to claim 3 of the present invention, there is provided a culture vessel which is formed into a double cylinder shape by an inner cylinder and an outer cylinder placed concentrically, and at least the outer cylinder is made of a transparent material that transmits visible light. A gas blowing port that opens in the lower part is disposed on either the left or right of the vertical plane that passes through the central axis of the inner cylinder and the outer cylinder, and the culture solution is blown into the culture vessel by blowing the gas from the gas blowing port. In order to form a swirling flow, sufficient agitation of the culture solution is facilitated, and all the microalgae can receive light fairly, thereby achieving high productivity. In addition, turbulent multiphase flow during the passage of bubbles in the culture solution, turbulent boundary layer on the wall surface and geltler vortex caused by the flow of the culture solution along the curved wall of the double cylindrical culture vessel The vortex from the curved wall of the outer cylinder to the curved wall of the inner cylinder and the curved wall of the inner cylinder to the curved wall of the outer cylinder is easily generated, and the culture solution is sufficiently stirred without stagnation by this vortex. The microalgae do not adhere to the wall of the culture vessel or form a colony and settle, the light transmission is not blocked by the microalgae, and the microalgae receive the microalgae in order to receive light efficiently and uniformly. Culture can be performed efficiently, and high culture efficiency can be maintained over a long period of time.
According to the fourth aspect of the present invention, there is provided a culture vessel formed of a double cylinder having an inner cylinder and an outer cylinder that are eccentrically placed horizontally, and at least the outer cylinder is made of a transparent material that transmits visible light. A gas blowing port that opens in the lower part is arranged on either the left or right of the vertical plane passing through the central axis of the inner cylinder, and the swirling flow of the culture solution is formed in the culture vessel by blowing the gas from the gas blowing port. Therefore, sufficient agitation of the culture solution is facilitated, and all microalgae can receive light fairly, thereby achieving high productivity. In addition, turbulent multiphase flow during the passage of bubbles in the culture solution, turbulent boundary layer on the wall surface and geltler vortex caused by the flow of the culture solution along the curved wall of the double cylindrical culture vessel The vortex from the curved wall of the outer cylinder to the curved wall of the inner cylinder and the curved wall of the inner cylinder to the curved wall of the outer cylinder is easily generated, and the culture solution is sufficiently stirred without stagnation by this vortex. The microalgae do not adhere to the wall of the culture vessel or form a colony and settle, the light transmission is not blocked by the microalgae, and the microalgae receive the microalgae in order to receive light efficiently and uniformly. Culture can be performed efficiently, and high culture efficiency can be maintained over a long period of time.
According to the invention described in claim 5, the gas injection ports are arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder of the culture vessel, and the two gas injection ports are alternately switched every predetermined time. Thus, the culture solution can be stirred more efficiently by alternately switching the swirling direction of the culture solution in the culture vessel.
The invention according to claim 6, that is, culturing by arranging a plurality of gas injection ports in the longitudinal direction of the culture vessel and sequentially injecting gas from the gas injection port on one end side of the culture vessel with a predetermined time difference. By forming a swirling flow of the culture solution that changes along the longitudinal direction of the culture vessel in the vessel, sufficient agitation of the culture solution can be realized to obtain high productivity, and cultivation of microalgae can be achieved. High culture efficiency can be maintained over a long period of time by preventing adhesion to the vessel wall surface and precipitation on the bottom surface of the culture vessel.
The invention according to claim 7, that is, a plurality of gas injection ports are alternately arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder along the longitudinal direction of the culture vessel, and from each gas injection port By blowing gas, a swirling flow of the culture solution whose direction is alternately different in the longitudinal direction can be formed in the culture vessel, so that sufficient agitation of the culture solution can be realized and high productivity can be obtained. High culture efficiency can be maintained over a long period of time by preventing adhesion of algae to the culture vessel wall surface and precipitation on the bottom surface of the culture vessel.
According to the invention described in claim 8, since the temperature of the culture solution can be controlled by sprinkling or passing the temperature-controlled water to the culture vessel, the culture solution is kept at a suitable temperature throughout the year regardless of the season. In particular, adverse effects on algae growth due to excessive heating of the culture solution in summer can be effectively eliminated.
<Best Mode for Carrying Out the Invention>
Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a perspective view of the microalgae culture apparatus according to the present invention, FIG. 2 is a cutaway front view of the microalgae culture apparatus (fracture sectional view in the direction of arrow A in FIG. 1), and FIG. 4 is a sectional view taken along line BB in FIG.
A microalgae culture apparatus 1 according to the present invention is configured by horizontally placing a culture vessel 2 having an outer shape in a drum shape on a support base 3.
As shown in FIGS. 2 to 3, the culture vessel 2 has a double-cylindrical inner cylinder 4 and an outer cylinder 5 that are concentrically placed horizontally by ring-shaped side walls 6 and 7. It is configured to be closed. That is, side walls 6 and 7 are respectively incorporated in the left and right ends of the inner cylinder 4 and the outer cylinder 5 placed concentrically, and a plurality of (6 in the example shown) are formed in the outer peripheral edges of the side walls 6 and 7. The culture vessel 2 whose outer shape forms a drum shape by passing a long bolt 8 horizontally through a circular hole (not shown) (see FIG. 1) and tightening a nut 9 screwed into the end of each bolt 8. Is assembled. In the present embodiment, the long bolt 8 is arranged outside the outer cylinder 5, but it may be arranged inside the inner cylinder 4. Moreover, you may employ | adopt the structure which attaches each side wall 6 and 7 each independently with a short volt | bolt and a nut screwed together. Further, a spacer may be interposed between the inner cylinder 4 and the outer cylinder 5 in order to prevent the inner cylinder 4 and the outer cylinder 5 from being bent. In this case, it is desirable to form a hole in the spacer.
On the other hand, arc-shaped fixing brackets 10 (see FIGS. 1 and 2) along the outer shape of the side walls 6 and 7 are provided on the left and right upper portions of the support base 3 having a frame shape. Are fixedly supported horizontally on the support base 3 by being fastened to the fixing bracket 10 by the two bolts 8 and nuts 9 screwed into the two bolts 8 on the left and right side walls 6, 7. .
Thus, the culture solution 11 is injected into the space surrounded by the inner cylinder 4 and the outer cylinder 5 and the side walls 6 and 7 formed in the culture vessel 2, and the liquid level is above the inner cylinder 4. It is kept higher than the end face. The left and right ends of the inner cylinder 4 and the outer cylinder 5 are connected to both side walls 6 and 7 via seal members (not shown), and the culture medium 11 leaks out of the culture vessel 2 by the sealing action of the seal members. It is prevented.
Here, the inner cylinder 4 and the outer cylinder 5 and both side walls 6 and 7 constituting the culture vessel 2 are made of a transparent material that transmits sunlight (visible light). In this embodiment, acrylic is used as the transparent material. Resin is used. As the transparent material, any material can be used as long as it is excellent in light transmittance and has high weather resistance and high ultraviolet resistance. For example, resin such as polycarbonate, polypropylene, polyethylene, polyvinyl chloride, glass, etc. Can be selected. In the present embodiment, the inner cylinder 4 and the outer cylinder 5 and the side walls 6 and 7 are made of a transparent member. However, in order to achieve the object of the present invention, at least the outer cylinder 5 is made of a transparent member. It should be.
As shown in FIGS. 2 to 4, a circular drain hole 5 a (see FIG. 4) is formed in the center lower portion in the width direction on the side close to one side wall 6 of the outer cylinder 5 of the culture vessel 2. A drain pipe 12 is inserted into and connected to the drain hole 5a. A drain valve 13 is provided in the middle of the drain pipe 12. By opening the drain valve 13, the culture solution 11 in the culture vessel 2 can be discharged to the outside.
Furthermore, the lower part of the outer cylinder 5 of the culture vessel 2 (specifically, as shown in FIG. 4, a horizontal plane F passing through the central axes of the inner cylinder 4 and the outer cylinder 5). _H A vertical plane F that is lower and passes through the same central axis _V A circular gas inlet 5b (see FIG. 3 and FIG. 4) is bored at three locations in the length direction of either one of the left and right sides.
A gas introduction pipe 14 is horizontally extended below the culture vessel 2 in the length direction, and three branch pipes 15 branched from the gas introduction pipe 14 and extending toward the culture vessel 2 side are provided. Each of the gas blowing ports 5b formed in the lower portion of the outer cylinder 5 of the culture vessel 2 is inserted and bound. Although not shown, the gas introduction pipe 14 is connected to a gas supply source such as a compressor that supplies air or a mixed gas of carbon dioxide and air.
On the other hand, a cylindrical gas discharge tube 16 is attached to the top of the culture vessel 2 (outer tube), and a gas discharge opening 17 that opens into the culture vessel 2 is formed inside thereof. An inverted dish-shaped cap 18 that opens downward is attached to the upper portion of the gas discharge cylinder 16, and the gas discharge opening 17 is covered with the cap 18, whereby the culture solution 11 in the culture vessel 2 is covered. It is possible to prevent contamination of dust, dirt or airborne microorganisms in the air. A similar effect can be obtained by providing a filter in the gas discharge opening 17 instead of the cap 18.
In addition, temperature control water introduction pipes 19 extend horizontally in parallel to the length direction on the left and right sides of the gas discharge cylinder 16 at the top of the culture vessel 2, and these temperature control water The introduction pipe 19 is inserted and supported by a pair of left and right support brackets 20 attached to the upper portions of the left and right side walls 6 and 7. As shown in FIG. 3, a plurality of water spouts 19a are formed in the lower portion of each temperature adjustment water introduction pipe 19, and the temperature adjustment water introduction pipe 19 is a temperature adjustment water (not shown) such as a cooling water pump. Connected to the supply source.
Next, the effect | action of the micro algae culture apparatus 1 which has the above structure is demonstrated.
The microalgae culture apparatus 1 is installed outdoors, and the microalgae to be cultured and the culture solution 11 are placed in the culture vessel 2, and a gas supply source (not shown) is driven to provide a gas containing carbon dioxide (air or carbon dioxide and When a gas mixture with air is passed through the gas introduction pipe 14, the gas is supplied from the three branch pipes 15 into the culture vessel 2.
The gas supplied into the culture vessel 2 becomes bubbles from the three bottom portions of the culture vessel 2 as shown in FIG. 4 and rises in the culture vessel 2, and in the process, carbon dioxide is supplied to the microalgae in the culture solution 11. Supply. As the gas bubbles rise, a flow of the culture solution 11 swirling in the same direction (counterclockwise in FIG. 4) is formed in the culture vessel 2 as indicated by an arrow in FIG.
Further, since the sunlight passes through the outer cylinder 5 and the side walls 6 and 7 made of a transparent member and enters the culture vessel 2, the microalgae in the culture vessel 2 are vitamins, amino acids, pigments, proteins by photosynthesis. In addition to producing useful components such as polysaccharides and fatty acids, carbon dioxide that contributes to global warming is absorbed. The oxygen generated by the photosynthetic action is discharged into the atmosphere through the gas discharge opening 17 formed at the top of the culture vessel 2 and the gap between the gas discharge tube 16 and the cap 18. In the present embodiment, an artificial light source can be installed in the center of the inner cylinder 4 of the culture vessel 2, and the microalgae can be continuously photosynthesised day and night. Is promoted.
Then, if necessary, if the temperature adjustment water supply source is driven and the temperature adjustment water (cooling water) flows through the temperature adjustment water introduction pipe 19, the temperature adjustment water is plurally provided in the temperature adjustment water introduction pipe 19. In order to control the temperature of the culture solution 11 in the culture vessel 2 by cooling it or the like, the temperature of the culture solution 11 is controlled throughout the year regardless of the season. In particular, adverse effects on algae growth due to excessive heating of the culture solution 11 in summer can be effectively eliminated. In the present embodiment, a configuration is adopted in which the temperature of the culture solution 11 is controlled by sprinkling temperature-controlled water on the outer surface of the outer cylinder 5 of the culture vessel 2, but not shown in the figure formed outside the outer cylinder 11. The same effect can be obtained by similarly controlling the temperature of the culture solution 11 by passing the temperature-controlled water through the water passage or the temperature-controlled water through the inner cylinder 4.
In the above, in the microalgae culture apparatus 1 according to the present embodiment, the swirl flow of the culture solution 11 is formed in the culture vessel 2 by blowing gas, so that the culture solution 11 is sufficiently agitated and all The microalgae can receive light fairly, thereby achieving high productivity.
In addition, the mixed-phase turbulent flow during the passage of bubbles in the culture solution 11, the turbulent boundary layer on the wall surface, and the Gertler vortex caused by the flow of the culture solution 11 along the curved wall of the culture vessel 2 having a double cylindrical shape A vortex is generated from the curved wall of the cylinder 5 toward the curved wall of the inner cylinder 4 and from the curved wall of the inner cylinder 4 to the curved wall of the outer cylinder 5, and the culture solution 11 is sufficiently agitated by this vortex without being retained, The microalgae is not attached to the wall of the culture vessel 2 or forming a colony, and the microalgae are not blocked by the microalgae, and the microalgae receive light efficiently and uniformly. Can be efficiently cultured, and high culture efficiency can be maintained over a long period of time.
If the microalgae adhere to the wall surface of the culture vessel 2 or form a colony and precipitate, it is not preferable because the light reception of the microalgae is hindered. However, according to the microalgae culture device 1, different types of mixed-phase turbulence and turbulence Since the boundary layer and the Gertler vortex (described in detail below) are generated, vortices and disturbances are generated between the inner cylinder 4 and the outer cylinder 5, and light transmission is not blocked by the microalgae.
Multiphase turbulence: turbulence caused by bubbles moving in the liquid phase
Turbulent boundary layer: When the flow passes near the wall surface, the Reynolds number, which is a parameter representing the similarity side of the flow, becomes high (the flow above the wall surface becomes faster or the distance at which the flow contacts the wall surface) The boundary layer, which is a slow layer formed near the wall surface, becomes turbulent. This turbulent layer is called a turbulent boundary layer.
Geltler vortex: When there is a flow in parallel with the curvature of the concave surface, the Reynolds number, which is a parameter representing the similarity law of the flow, increases (the flow above the wall becomes faster or the distance that the flow contacts the wall becomes longer) This produces a rotating vortex perpendicular to the flow. This rotating vortex is called the Gertler vortex.
Furthermore, since the culture vessel 2 is composed of the inner cylinder 4 and the outer cylinder 5 having a high pressure resistance, the thickness of the culture apparatus 1 can be reduced and the culture apparatus 1 can be reduced in weight and cost.
Moreover, in this Embodiment, the culture container 2 can be comprised easily by arrange | positioning the inner cylinder 4 and the outer cylinder 5 which consist of a cylinder concentrically.
In the culture vessel 2 in which the inner cylinder 4 and the outer cylinder 5 are arranged concentrically, a horizontal plane F passing through the central axis of the inner cylinder 4 and the outer cylinder 5 through the gas blowing port 5b. _H A vertical plane F that is lower and passes through the same central axis _V Therefore, it is possible to easily form a flow of the culture solution 11 rotating in one direction in the culture vessel 2 and to easily generate a multiphase turbulent flow, a turbulent boundary layer, and a geltler vortex. In addition, as shown in FIG. _V If it is formed on the opposite side, the flow of the culture solution 11 swirling in the opposite direction to the present embodiment (clockwise in FIG. 5) can be formed. In addition, although not shown, if gas inlets are formed on the left and right sides of the vertical plane passing through the central axis of the inner and outer cylinders, and the two inlets are alternately switched every predetermined time, the culture solution in the culture vessel The swirl direction can be switched alternately, and the culture solution can be stirred more efficiently. Furthermore, you may make it change the turning direction of the culture solution 11 partly or transiently partially in the longitudinal direction of the culture vessel 2. A plurality of gas injection ports 5b are arranged in the longitudinal direction of the culture vessel 2, and a culture vessel of the culture solution 11 is introduced into the culture vessel 2 by sequentially injecting gas from the gas injection ports 5b on one end side of the culture vessel 2 with a predetermined time difference. You may form the swirl | vortex flow which changes along 2 longitudinal directions. A plurality of gas blowing ports 5b are alternately arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder along the longitudinal direction of the culture vessel 2, and the gas is blown from each gas blowing port 5b to enter the culture vessel 2 However, a swirl flow of the culture solution 11 may be alternately formed in the longitudinal direction.
By the way, in this embodiment, the inner tube 4 and the outer tube 5 made of a cylinder are arranged concentrically to constitute the culture vessel 2. However, as shown in FIG. 6, the inner tube 4 and the outer tube 5 made of a cylinder. The culture vessel 2 may be configured by arranging the gas outlets eccentrically, and in this case, the gas blowing port 4a is passed through the central axis of the inner cylinder 4 as shown in the horizontal plane F. _H A vertical plane F that is lower and passes through the same central axis _V Can be easily formed in the culture vessel 2 to swirl the culture medium 11 in the same direction (counterclockwise in the illustrated example), and mixed phase turbulence, turbulent boundary layer, Gerdler vortices are easy to generate.
Further, as shown in FIG. 7, an inner cylinder 4 ′ and an outer cylinder 5 ′ made of an elliptic cylinder are concentrically arranged to constitute a culture vessel 2 ′, or an inner cylinder made of a long cylinder as shown in FIG. The culture vessel 2 ″ may be configured by concentrically arranging 4 ″ and the outer cylinder 5 ″. In these cases, the gas inlets 4a ′ and 5b ″ are connected to the inner cylinder 4 ′ and 4 ″ and the outer cylinder 5 respectively. Horizontal plane F passing through the central axis of ', 5 " _H A vertical plane F that is lower and passes through the same central axis _V The flow of the culture solution 11 swirling in the same direction (counterclockwise in the illustrated example) can be formed in the culture vessels 2 ′ and 2 ″. In addition, the culture vessel may be configured by arranging the inner cylinder and the outer cylinder made of an elliptical cylinder or a long cylinder in an eccentric manner. In these cases, the gas inlet is located below the horizontal plane passing through the central axis of the inner cylinder. In addition, the flow of the culture solution swirling in the same direction can be formed in the culture vessel by arranging it on either the left or right side of the vertical plane passing through the same central axis.
Here, FIG. 9 shows an example of actual production equipment using the microalgae culture apparatus 1 according to the present embodiment. In the actual production equipment, a plurality of microalgae culture apparatuses 1 are arranged in a row as shown in the figure. Those connected continuously are arranged over several rows. In this case, each gas introduction pipe 14 and each two temperature-controlled water introduction pipes 19 are shared for each culture apparatus 1 in each row.
Next, the result of the culture experiment performed using the microalgae culture apparatus according to the present invention will be described.
Cultivation experiments were performed over 13 days using Chlorococcum litorale as a microalgae. In this case, the sunshine duration is 10 hours / day, and the photon amount in the south and middle is 800 μmol / m. ² / S, daytime average photon amount 340 μmol / m ² The culture result was an average growth rate of 0.15 g dry weight / liter / day. Also, no microalgae adhered to the culture vessel wall during the culture period.
In another culture experiment, as a result of culturing Spirulina platensis as a microalgae, the conventional culture pond system has a culture concentration of 0.3 to 0.5 g / liter and a daily productivity of 0.1. The microalgae culture apparatus according to the present invention has a good result of a culture concentration of 10 to 20 g / liter and a productivity per day of 2.8 to 7.0 g / liter, whereas it is ˜0.2 g / liter. It was.
<Industrial applicability>
As is clear from the above description, according to the present invention, a culture solution is placed in a culture vessel having an opening at the top, and visible light is incident while blowing a gas containing carbon dioxide into the culture solution. In the microalgae culturing apparatus for culturing microalgae in the culture vessel, the culture vessel is formed into a double cylinder composed of an inner cylinder and an outer cylinder placed horizontally, and at least the outer cylinder transmits visible light. Since the swirl flow of the culture solution is formed in the culture vessel by blowing the gas, it is possible to achieve sufficient productivity by realizing sufficient stirring of the culture solution, It is possible to obtain an effect that high culture efficiency can be maintained over a long period of time by preventing adhesion of microalgae to the culture vessel wall surface and precipitation on the bottom surface of the culture vessel.
Further, according to the present invention, a culture solution is placed in a culture vessel having an opening at the top, and a visible ray is incident on the culture solution by injecting a gas containing carbon dioxide into the culture solution. In a microalgae culture method for culturing microalgae, a culture vessel formed of a transparent material that transmits at least visible light, which is formed into a double cylinder shape with an inner cylinder and an outer cylinder placed concentrically The gas inlet opening at the lower part of the gas cylinder is arranged on either the left or right side of the vertical plane passing through the central axis of the inner cylinder and the outer cylinder, and the gas is blown from the gas inlet, or eccentrically placed horizontally. The gas injection port that opens at the bottom of the culture vessel formed of a transparent material that transmits visible light is formed at least by the inner cylinder and the outer cylinder. Arranged on either the left or right side of the vertical plane In addition, since the swirling flow of the culture solution is formed in the culture vessel by blowing the gas from the gas blowing port, sufficient agitation of the culture solution can be easily realized and high productivity can be obtained. It is possible to obtain an effect that high culture efficiency can be maintained over a long period of time by preventing algae from adhering to the culture vessel wall surface and precipitation on the bottom surface of the culture vessel.
[Brief description of the drawings]
FIG. 1 is a perspective view of a microalgae culture apparatus according to the present invention.
FIG. 2 is a cutaway front view (fracture sectional view in the direction of arrow A in FIG. 1) of the microalgae culture apparatus according to the present invention.
FIG. 3 is a side sectional view of the microalgae culture apparatus according to the present invention.
4 is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a cross-sectional view showing another embodiment of the culture vessel of the microalgae culture apparatus according to the present invention.
FIG. 6 is a cross-sectional view showing another embodiment of the culture vessel of the microalgae culture apparatus according to the present invention.
FIG. 7 is a cross-sectional view showing another embodiment of the culture vessel of the microalgae culture apparatus according to the present invention.
FIG. 8 is a cross-sectional view showing another embodiment of the culture vessel of the microalgae culture apparatus according to the present invention.
FIG. 9 is a perspective view showing an example of actual production equipment using the microalgae culture apparatus according to the present invention.
In the figure, reference numeral 1 is a microalgae culture apparatus, 2,2 ', 2 "are culture vessels, 4,4', 4" are inner cylinders, 4a, 4a 'are gas inlets, 5,5,5, "Is an outer cylinder, 5b, 5b" is a gas inlet, 6 and 7 are side walls, 11 is a culture solution, 14 is a gas introduction pipe, 17 is a gas discharge opening, 18 is a cap, 19 is a temperature-controlled water introduction pipe It is.

Claims (8)

Microalgae culture for culturing microalgae in the culture vessel by putting visible light into the culture broth while blowing a gas containing carbon dioxide into the culture solution having an opening at the top In the device
The culture vessel is formed into a double cylindrical shape composed of a horizontally placed inner cylinder and an outer cylinder, and at least the outer cylinder is made of a transparent material that transmits visible light, and the swirling flow of the culture solution is put into the culture container. A microalgae culture apparatus characterized in that a gas inlet for injecting a gas for forming a gas is opened in the lower part of the culture vessel.   The microalgae according to claim 1, wherein the inner cylinder and the outer cylinder are constituted by a cylinder, an elliptic cylinder, or a long cylinder, and the inner cylinder and the outer cylinder are arranged concentrically or eccentrically. Culture device. Microalgae culture for culturing microalgae in the culture vessel by putting visible light into the culture broth while blowing a gas containing carbon dioxide into the culture solution having an opening at the top In the method
A gas blowing port that opens in the lower part of the culture vessel formed of a transparent material that is formed of a transparent material that allows visible light to pass through is formed into a double cylindrical shape by an inner cylinder and an outer cylinder that are concentrically placed, A fine arrangement characterized in that it is arranged on either the left or right side of the vertical plane passing through the central axis of the cylinder and the outer cylinder, and the swirling flow of the culture solution is formed in the culture vessel by blowing the gas from the gas blowing port. Algal culture method. Microalgae culture for culturing microalgae in the culture vessel by putting visible light into the culture broth while blowing a gas containing carbon dioxide into the culture solution having an opening at the top In the method
A gas injection port that opens at the bottom of a culture vessel formed of a transparent material that is formed of a transparent material that transmits visible light is formed into a double cylinder shape with an inner cylinder and an outer cylinder that are eccentrically placed horizontally. A method for culturing microalgae, which is arranged on either the left or right side of a vertical plane passing through the central axis of a cylinder and forms a swirling flow of the culture solution in a culture vessel by blowing the gas from the gas blowing port .   The gas blowing ports are arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder of the culture vessel, and the swirl directions of the culture medium in the culture vessel are alternately switched by alternately switching both gas blowing ports every predetermined time. The method for culturing microalgae according to claim 3 or 4, wherein switching is performed.   A plurality of gas injection ports are arranged in the longitudinal direction of the culture vessel, and gas is sequentially blown from the gas injection port on one end side of the culture vessel with a predetermined time difference in the culture vessel in the longitudinal direction of the culture vessel. The microalgae culture method according to claim 3 or 4, wherein a swirling flow that changes along the flow path is formed.   A plurality of gas inlets are alternately arranged on the left and right of the vertical plane passing through the central axis of the inner cylinder along the longitudinal direction of the culture vessel, and the direction is longitudinal in the culture vessel by blowing gas from each gas inlet 5. The method of culturing microalgae according to claim 3 or 4, wherein swirl flows of different culture solutions are alternately formed.   Sprinkling of temperature-controlled water to the outer surface of the outer cylinder of the culture vessel, passing temperature-controlled water to a water passage formed outside the outer cylinder, or passing temperature-controlled water into the inner cylinder The method for culturing microalgae according to any one of claims 3 to 7, wherein the temperature is controlled.

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