Algae culture apparatus

Abstract

To provide an algae culture apparatus capable of enhancing freedom in placement of a culture tank and allowing low-cost algae cultivation.SOLUTION: An algae culture apparatus 1 comprises: a plurality of culture tanks 10 for culturing algae 3 in a culture solution 2; and an algae transfer device 20 that connects the plurality of culture tanks 10 and sequentially transfers the algae 3 from an upstream culture tank 10 to a downstream culture tank 10. The algae transfer device 20 separates algae 3 equal to or smaller than a specific size and the culture solution 2, and transfers the algae 3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an algae cultivation apparatus. [Background technology]

[0002] Patent Document 1 below discloses a multistage continuous seaweed cultivation device. This multistage continuous cultivation device is equipped with multistage cultivation tanks that store cultivation seawater and in which the installation level of each cultivation tank from the first tank to the final cultivation tank is lowered in stages, and transfer pipes with on-off valves that connect the bottom of each cultivation tank to the subsequent cultivation tank. Seaweed is transferred between the previous and subsequent cultivation tanks by opening and closing the valves of the transfer pipes that connect them, utilizing the natural flow of cultivation seawater due to gravity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5698158 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional technology, the culture solution (seawater for culture) is allowed to flow down along with the algae, so the design must take into account the installation height of the culture tank, which limits the flexibility of the culture tank installation. Furthermore, when the culture solution is allowed to flow down by gravity, there is an advantage in that no electricity costs are incurred in transferring it from the upstream to the downstream tank, but as the culture solution in the upstream tank gradually decreases, it is necessary to pump up the culture solution using a pump or the like, which ultimately makes it unavoidable to incur electricity costs.

[0005] An object of the present invention is to provide an algae culture apparatus that allows for improved flexibility in the installation of culture tanks and enables algae to be cultured at low cost. [Means for solving the problem]

[0006] In order to solve the above problems, an algae culture device according to a first aspect of the present invention comprises a plurality of culture tanks for cultivating algae in a culture solution, and an algae transfer device that connects the plurality of culture tanks and sequentially transfers the algae from the upstream culture tank to the downstream culture tank, and the algae transfer device separates the algae that are below a certain size from the culture solution and transfers the algae.

[0007] The algae culture apparatus according to the second aspect of the present invention may be the algae culture apparatus according to the first aspect of the present invention, wherein the algae transfer device comprises a conveyor belt having openings of the specified size.

[0008] An algae culture apparatus according to a third aspect of the present invention is an algae culture apparatus according to the second aspect of the present invention, wherein the conveyor belt provided in the upstream culture tank may have a smaller mesh size than the conveyor belt provided in the downstream culture tank.

[0009] An algae culture apparatus according to a fourth aspect of the present invention is an algae culture apparatus according to the second or third aspect of the present invention, wherein the conveyor belt may be formed with protrusions for scooping up the algae from the culture solution.

[0010] An algae culture apparatus according to a fifth aspect of the present invention may be an algae culture apparatus according to any of the first to fourth aspects of the present invention, further comprising a concentration measuring device that measures the concentration of the algae, and a control device that drives the algae transfer device based on the measurement results of the concentration measuring device.

[0011] An algae culture apparatus according to a sixth aspect of the present invention may be an algae culture apparatus according to the fifth aspect of the present invention, further comprising a light source that irradiates light onto the culture solution, and the concentration measuring device measures the concentration of the algae based on the intensity of the light that has passed through the culture solution.

[0012] The algae culture apparatus according to the seventh aspect of the present invention may be an algae culture apparatus according to any one of the first to sixth aspects of the present invention, further comprising an agitation device for agitating the culture medium and suspending the algae in the culture medium.

[0013] An algae culture apparatus according to an eighth aspect of the present invention is an algae culture apparatus according to any one of the first to seventh aspects of the present invention, wherein the multiple culture tanks are formed by dividing the interior of a single tank. [Effects of the Invention]

[0014] According to the above aspect of the present invention, the flexibility in installing the culture tank can be improved, and algae can be cultured at low cost. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view of an algae culture apparatus according to a first embodiment of the present invention. [Figure 2] 1 is a side view of an algae culture apparatus according to a first embodiment of the present invention. [Figure 3] FIG. 4 is a plan view of an algae culture apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an algae culture apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. First, an overview of the embodiment of the present invention will be described, and then details of each embodiment of the present invention will be described.

[0017] 〔overview〕 Algae cultivation on land is widely practiced, but low-cost cultivation is essential for all types of algae. The main costs incurred in algae cultivation are electricity and water. Various types of tanks have been devised for cultivation, but a common method is to pass the algae through multiple tanks with different conditions in stages to cultivate them under optimal conditions depending on their growth. When using multiple tanks, the method of transferring the algae from tank to tank becomes an issue. Typically, the algae are transferred together with the water using a pump, but since not only the algae but also the water is transferred, electricity costs are incurred for the transfer pump. The concentration of algae in the water in the cultivation tank is generally at most about 2% of the total. Therefore, transferring the algae together with the water transfers 50 times the weight compared to transferring only the algae.

[0018] The above-mentioned Patent Document 1 proposes a method in which multiple water tanks are installed in a stepped configuration and water is transferred by gravity. This method has the advantage of not incurring electricity costs when transferring water from top to bottom. However, the design must take into account the installation height of the water tanks, which limits the flexibility of installation of the water tanks. Furthermore, if water that has fallen to the bottom is to be reused, electricity costs for raising the water to the top again are unavoidable. Furthermore, if the water is not reused but discarded, there is a problem of the cost of newly adding water.

[0019] Furthermore, the water-in-water transfer method simply transfers all the algae in the tank along with the water, and does not allow for adjustment or classification based on the algae's growth size. Generally, macroalgae are cultivated starting at a few millimeters or less and harvested when they reach a size of several tens of millimeters or more. However, optimal cultivation conditions for macroalgae often vary depending on their size. Because algae are living organisms, their growth rates vary even under the same conditions. Even when algae of the same size are supplied and cultivated in the same tank, they grow along a uniform distribution from a median value, and they do not all reach a perfectly uniform size. Therefore, the water-in-water method has the problem of algae, including those that are not fully grown, being sent to the next tank after a certain period of time, resulting in deviation from optimal conditions. Furthermore, the water-in-water method involves intermittent transfer over time, which necessitates operational control, such as the addition of water after transfer. Automating these controls requires the installation of necessary equipment, such as automatic valves, pumps, and level gauges, and the establishment of control methods. Manual transfer operations incur labor costs for starting and starting pumps and checking the transfer.

[0020] In an embodiment of the present invention, in an algae transfer device in which multiple culture tanks are connected in series and algae are transferred sequentially to downstream tanks, algae below a certain size are separated from the culture solution before transfer. This reduces the transfer weight and allows only algae that have grown to a certain size to be selectively transferred to the downstream tank. Therefore, the culture tanks can be maintained at appropriate culture conditions according to the growth size of the algae, allowing the transfer and cultivation of algae at low cost.

[0021] [First embodiment] Fig. 1 is a plan view of an algae culture apparatus 1 according to a first embodiment of the present invention, Fig. 2 is a side view of the algae culture apparatus 1 according to the first embodiment of the present invention. As shown in these figures, the algae culture apparatus 1 includes a culture tank 10, an algae transfer device 20, and a recovery and dewatering tank 30.

[0022] In the following description, an XYZ Cartesian coordinate system is set, and the positional relationship of each component is sometimes described with reference to this XYZ Cartesian coordinate system. The X-axis direction is a first horizontal direction. The Y-axis direction is a second horizontal direction that is perpendicular to the first horizontal direction. The Z-axis direction is a vertical direction that is perpendicular to the first and second horizontal directions.

[0023] The culture tank 10 holds the culture solution 2, and the algae 3 is cultivated in the culture solution 2. The culture solution 2 is seawater if the algae 3 is seaweed such as wakame seaweed or kombu seaweed, but it may also be freshwater depending on the type of algae 3. The culture solution in the culture tank 10 is monitored to maintain an appropriate water quality corresponding to the size of the algae 3 present, and necessary components are replenished and unnecessary substances are removed. Unnecessary substances can be removed using common methods such as adsorption, biological treatment, filtration, and the promotion of various decomposition reactions.

[0024] The algae culture apparatus 1 is equipped with multiple culture tanks 10 (culture tanks 10A to 10C). Installing too many culture tanks 10 increases the number of algae transfer devices 20 (described below) attached to the culture tanks 10, which increases costs, so it is preferable to install between two and ten culture tanks 10. As shown in FIG. 2, the multiple culture tanks 10 are installed at the same height, but they can be installed at any height. As shown in FIG. 1, the multiple culture tanks 10 have different volumes corresponding to the growth of the algae 3, but they may also have the same volume. Although the multiple culture tanks 10 are formed in a rectangular shape in a plan view, they may be circular, polygonal, or a combination of circular and polygonal shapes as long as the culture solution 2 does not stagnate.

[0025] The algae transfer device 20 connects multiple culture tanks 10 and sequentially transfers algae 3 from the upstream culture tank 10 to the downstream culture tank 10. As shown in FIG. 1 , the algae transfer device 20 is installed across the culture tanks 10 in a plan view. The algae transfer device 20 connects multiple culture tanks 10 arranged in series in the X-axis direction, alternately in the Y-axis direction. Specifically, an algae supply device 11 is installed on the +Y side of the most upstream culture tank 10A. The algae transfer device 20A installed in the culture tank 10A connects the -Y sides of the culture tank 10A and the culture tank 10B. The algae transfer device 20B installed in the culture tank 10B connects the +Y sides of the culture tank 10B and the culture tank 10C. The algae transfer device 20C installed in the culture tank 10C connects the -Y side of the culture tank 10C to the recovery and dewatering tank 30.

[0026] The algae transfer device 20 is equipped with a conveyor belt 21 that separates the algae 3 below a specific size from the culture solution 2 and transfers the algae 3. The conveyor belt 21 has openings of a specific size. For example, if the conveyor belt 21 is a mesh belt or a perforated belt, the size of the openings can be determined by the size of the openings. The openings of the conveyor belt 21 can be set arbitrarily to match the size of the algae 3 to be transferred, but if they are too fine, problems such as clogging of the openings are likely to occur. Therefore, the openings of the conveyor belt 21 are preferably within the range of 5 mm to 50 mm, and should be selected appropriately depending on the type of algae 3 to be cultured.

[0027] The size of the algae 3 before cultivation can be any size, but if the size is too small, it becomes difficult to classify the algae 3. For this reason, it is preferable to start cultivation by introducing algae 3 of about 3 mm to 5 mm from the algae supply device 11. In this case, it is preferable to use a conveyor belt 21a with openings the size of the algae 3 to be introduced (5 mm or less) for the algae transfer device 20A provided in the most upstream cultivation tank 10A. This allows algae 3 larger than the size of the introduced algae 3 to be classified.

[0028] Furthermore, the size at which the algae 3 are most efficiently harvested varies depending on the type of algae 3, but it is generally considered preferable to harvest at 30 mm to 100 mm. For this reason, it is preferable to use a conveyor belt 21c with mesh openings of 30 mm or more for the algae transfer device 20C provided in the most downstream culture tank 10C. It is also preferable to use a conveyor belt 21b with mesh openings greater than 5 mm and smaller than 30 mm for the algae transfer device 20B provided in the intermediate culture tank 10B. In other words, the conveyor belt 21 provided in the upstream culture tank 10 has smaller mesh openings than the conveyor belt 21 provided in the downstream culture tank 10. It is to be noted that when transferring the algae 3, the size at which the algae 3 should be transferred to the next tank depends on the type of algae 3, and therefore the optimal value must be considered for each tank.

[0029] The size of the algae 3 being transported can be adjusted by adjusting the mesh size of the conveyor belt 21. Adjusting the mesh size of the conveyor belt 21 can be easily achieved by replacing the belt. By determining the optimal cultivation conditions for each size of algae 3 in advance and transferring the algae 3 to the next tank when the optimal size is reached, the algae 3 can be cultivated efficiently. Similarly, the final harvest of the algae 3 can be adjusted by setting an arbitrary mesh size, and harvesting at a uniform size is preferable because it reduces variation in quality control. It is preferable to determine the harvest size after thorough economic considerations, but because these classification sizes can be easily changed by adjusting the mesh size of the conveyor belt 21, they may also be optimized based on operational experience after the algae cultivation device 1 is installed.

[0030] As shown in FIG. 2, one end of the conveyor belt 21 is placed in the liquid in the upstream culture tank 10 (e.g., culture tank 10A), and the other end of the conveyor belt 21 is placed above the liquid surface in the downstream culture tank (e.g., culture tank 10B). The conveyor belt 21 has protrusions formed thereon that scoop up the algae 3 from the culture solution 2. The protrusions may be plate-shaped or pin-shaped. This allows the algae 3 to be efficiently scooped up from the culture solution 2. However, if the culture tanks 10 are spaced far apart, the algae transfer device 20 will become larger, so it is preferable to place the culture tanks 10 adjacent to each other or within a range of several meters.

[0031] The transport capacity of the algae 3 is determined by the width and rotation speed (transport speed) of the conveyor belt 21, but rotating it too fast can shorten the life of the device. Furthermore, if the conveyor belt 21 is too wide, it becomes difficult to manufacture and install the conveyor belt 21. Therefore, the conveyor belt 21 should be designed to have a width and rotation speed that make it easy to manufacture, and if even more transport capacity is required, an algae transport device 20 may be installed in parallel. When using seawater as the culture solution 2, it is preferable to use, as much as possible, resin-based conveyor belts 21 and their peripheral parts that do not rust.

[0032] As shown in Figure 2, the culture tank 10 is equipped with a light source 12 that irradiates the culture solution 2 with light. The light source 12 is generally located at the top of the culture tank 10 and irradiates the algae 3 with the light necessary for culturing the algae 3. The light source 12 can be sunlight or artificial light, such as an LED, that is optimal for the algae 3 being cultured. When irradiating light from above, if the culture tank 10 is too deep, the light will be absorbed by the algae 3 in the middle and will not reach the bottom of the culture tank 10, slowing the growth rate of the algae 3 at the bottom. Therefore, it is recommended to adjust the depth of the culture tank 10 or install submerged light sources in the culture tank 10 to supplement the light. When installing submerged light sources, it is recommended to compare the benefits of increased cultivation rate with the electricity costs required for the light sources and install the necessary number of light sources with appropriate intensity in appropriate locations. While the culture tank 10 can be operated under any depth, if it is too deep, light will not reach the bottom of the culture tank 10, and if it is too shallow, it will be difficult to install and operate the conveyor belt 21. Therefore, the depth of the culture tank 10 (the water level of the culture solution 2) is preferably within the range of 0.5 m to 5 m.

[0033] As shown in FIG. 2, the culture tank 10 is equipped with an agitator 13 that agitates the culture solution 2 and suspends the algae 3 in the culture solution 2. The agitator 13 blows air into the bottom of the culture tank 10 to agitate the culture solution 2. It is preferable to blow air using a general blower at an optimal flow rate and bubble diameter for the algae 3. It is also advisable to determine the location and amount of air to be blown in so as to prevent stagnation of the culture solution 2.

[0034] The agitator 13 may agitate the culture solution 2 by moving the water using an agitator blade or a pump installed in the culture tank 10. The agitation of the culture solution 2 may be performed by blowing in air and moving the water, either alone or in combination. When combining the two methods, electricity costs are required, so it is advisable to compare the resulting effect of promoting the cultivation of the algae 3 with the electricity costs required for agitation and then determine the agitation method and intensity.

[0035] To reduce electricity costs, it is preferable that the algae transfer device 20 be operated continuously with variable speed control or ON-OFF control. Therefore, the algae culture device 1 is equipped with a concentration measuring device 40 that measures the concentration of the algae 3, and a control device 41 that drives the algae transfer device 20 based on the measurement results of the concentration measuring device 40. As shown in Figure 2, when light is irradiated from above the culture tank 10, it is preferable to install the concentration measuring device 40 at the bottom of the culture tank 10 and measure the concentration of the algae 3 by detecting the intensity of light transmitted through the culture solution 2.

[0036] That is, when light is irradiated from above the culture tank 10, as the algae 3 grow and the concentration of the algae 3 increases, the proportion of light from above that is absorbed by the algae 3 increases, and the amount of light that reaches the bottom of the culture tank 10 becomes weaker. For this reason, a concentration measuring device 40 equipped with a photosensor may be provided at the bottom of the culture tank 10, and the algae transfer device 20 may be controlled at a variable speed or ON-OFF by a control device 41 so that the amount of light that reaches the bottom is within a certain range. This allows the amount of algae 3 transferred by the algae transfer device 20 to be adjusted, and the algae 3 in the culture tank 10 to have a constant concentration.

[0037] For example, if the amount of light reaching the bottom of the culture tank 10 weakens, this means that the concentration of algae 3 has increased, so it is recommended to increase the amount of algae 3 being transferred from the culture tank 10 by increasing the operating speed of the algae transfer device 20 or starting the algae transfer device 20 if it is stopped. Conversely, if a lot of light reaches the bottom of the culture tank 10, this means that the proportion of light from above that is absorbed by the algae 3 has decreased, so in this case, it is recommended to reduce the amount of algae 3 being transferred from the culture tank 10 by slowing down the operating speed of the algae transfer device 20 or stopping the algae transfer device 20. Note that any common optical sensor that can be used underwater can be used as the concentration measuring device 40. Furthermore, if an underwater light source is provided in the culture tank 10 in addition to irradiating light from above, it is recommended to measure the light intensity at the part of the culture tank 10 farthest from the light source. Light intensity is often expressed in units of lux, but since sunlight on a typical sunny day is about 50,000 lux, any light sensor that can detect light at the bottom of the culture tank 10 with an intensity in the range of 50,000 lux to 100 lux will suffice.

[0038] With the algae transfer device 20 configured as described above, small, ungrown algae 3 and the culture solution 2 pass through the openings in the conveyor belt 21 and remain in the culture tank 10, while algae 3 that have grown to a certain size are transferred to the downstream culture tank 10. This method of transferring only the algae 3 eliminates the need to consider the natural flow of the culture solution 2, improving the flexibility of installation of the culture tank 10. Furthermore, with the method of transferring only the algae 3, the transfer weight is approximately 1 / 50 of the method of transferring the algae 3 together with the water, allowing the algae 3 to be transferred at low cost. Furthermore, because only the algae 3 that have grown to a specific size can be selectively transferred to the downstream tank, the culture tank 10 can be maintained at appropriate culture conditions according to the growth size of the algae 3, promoting the growth of the algae 3.

[0039] At the outlet side of the algae transfer device 20, clogging of the conveyor belt 21 and adhesion of the algae 3 may be prevented by spraying water onto the conveyor belt 21 to wash the algae 3. Furthermore, in the algae transfer device 20C provided in the most downstream culture tank 10C, fresh water may be sprayed onto the algae 3 on the conveyor belt 21c to wash them, thereby eliminating the need for a subsequent washing step. The algae 3 thus obtained are introduced into the recovery and dehydration tank 30 and dehydrated. The recovery and dehydration tank 30 may be equipped with a mixer that crushes the introduced algae 3, uniforms the size, and discharges the crushed algae 3. Thus, according to this embodiment, the process from introducing the algae 3 to harvesting can be carried out continuously, eliminating the need for labor for transportation and enabling low-cost operation up to dehydration.

[0040] As explained above, the algae culture device 1 according to this embodiment includes a plurality of culture tanks 10 for culturing algae 3 in a culture solution 2, and an algae transfer device 20 that connects the plurality of culture tanks 10 and sequentially transfers the algae 3 from the upstream culture tank 10 to the downstream culture tank 10, and the algae transfer device 20 separates the algae 3 below a certain size from the culture solution 2 and transfers the algae 3. This configuration improves the flexibility in installing the culture tanks 10 and enables the algae 3 to be cultured at low cost.

[0041] Furthermore, in this embodiment, the algae transfer device 20 includes a conveyor belt 21 with openings of a specific size. With this configuration, the conveyor belt 21 has appropriate openings, allowing small, ungrown algae 3 to pass through the openings and remain in the culture tank 10, while algae 3 that have grown to a certain size can be preferentially transferred to a downstream tank.

[0042] Furthermore, in this embodiment, the conveyor belt 21 provided in the upstream culture tank 10 among the multiple culture tanks 10 has smaller mesh sizes than the conveyor belt 21 provided in the downstream culture tank 10. Specifically, the algae transfer device 20A provided in the most upstream culture tank 10A has a conveyor belt 21a with mesh sizes of 5 mm or less, and the algae transfer device 20C provided in the most downstream culture tank 10C among the multiple culture tanks 10 has a conveyor belt 21c with mesh sizes of 30 mm or more. With this configuration, algae 3 can be cultured starting from a small size that is easy to classify, and can be harvested at a large size that is suitable for harvesting.

[0043] Furthermore, in this embodiment, the conveyor belt 21 is formed with protrusions that scoop up the algae 3 from the culture solution 2. With this configuration, the algae 3 can be efficiently scooped up from the culture solution 2.

[0044] This embodiment also includes a concentration measuring device 40 that measures the concentration of the algae 3, and a control device 41 that drives the algae transfer device 20 based on the measurement results of the concentration measuring device 40. With this configuration, the amount of algae 3 transferred by the algae transfer device 20 can be adjusted so that the concentration of the algae 3 in the culture tank 10 is constant.

[0045] Furthermore, this embodiment includes a light source 12 that irradiates light onto the culture solution 2, and the concentration measuring device 40 measures the concentration of the algae 3 based on the intensity of light that has passed through the culture solution 2. With this configuration, the concentration of the algae 3 can be measured using the light source 12 that irradiates light necessary for culturing the algae 3.

[0046] This embodiment also includes an agitator 13 that agitates the culture solution 2 and suspends the algae 3 in the culture solution 2. With this configuration, the culture solution 2 can be agitated to promote the cultivation of the algae 3.

[0047] Second Embodiment Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0048] FIG. 3 is a plan view of an algae culture apparatus 1 according to a second embodiment of the present invention. As shown in FIG. 3, the multiple culture vessels 10 of the second embodiment are formed by partitioning the inside of a single vessel 100.

[0049] Specifically, the interior of the tank 100 is partitioned by a plurality of partition members 101. The algae transfer device 20 is arranged so as to straddle the partition members 101. This configuration allows for the same functionality as in the first embodiment. The method shown in FIG. 3 has the advantage that the algae transfer device 20 can be made smaller and less expensive because a plurality of culture tanks 10 are adjacent to each other. It is preferable that the shape of the tank 100 is rectangular or circular in plan view, as this reduces manufacturing costs. Conversely, shapes with acute angles are not preferable for the shape of the tank 100, as they tend to become areas where the culture solution 2 and algae stagnate.

[0050] A water quality control device 50 is connected to the tank 100. The water quality control device 50 is connected to the culture tank 10A via a first flow path 51 provided with a first valve 51a. The water quality control device 50 is also connected to the culture tank 10B via a second flow path 52 provided with a second valve 52a. The water quality control device 50 is also connected to the culture tank 10C via a third flow path 53 provided with a third valve 53a. In the algae culture apparatus 1, the culture solution 2 in the culture tank 10 remains in the culture tank 10 without moving, so the water quality control device 50 replaces the necessary amount of culture solution 2 as needed, sterilizes the culture solution 2, and so on. The water quality control device 50 also replenishes any decrease in the culture solution 2.

[0051] In this way, the culture solution 2 in each culture tank 10 is monitored to maintain an appropriate water quality for the size of the algae 3 present, and necessary components are replenished and unnecessary components are removed. In this algae culture device 1, the culture solution 2 is not moved when the algae 3 are transferred, so water quality can be maintained by treating only the minimum amount of culture solution 2 necessary to maintain water quality. Furthermore, if there is a difference in the target water quality between the upstream and downstream culture tanks 10, water quality detection and adjustment are generally performed for each culture tank 10. However, if the difference in target water quality is small, the water quality of each culture tank 10 can be detected and adjusted simultaneously. In this case, water quality detectors and adjustment equipment can be shared, reducing costs. Furthermore, when designing the algae culture device 1, it is recommended to first determine the optimal water quality for the size of the algae 3, determine the number of culture tanks 10 required, and then determine the amount of component replenishment and water volume required for each tank.

[0052] While the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0053] For example, in the above embodiment, the algae transfer device 20 is exemplified as having a configuration including a conveyor belt 21 with openings of a specific size, but other configurations are also possible as long as they can separate the algae 3 below the specific size from the culture solution 2 and transfer the algae 3. For example, a configuration may be used in which a screen with slits of a specific width is formed to separate the algae 3 below the specific size from the culture solution 2, and claws that move along the slits scoop up and transfer the algae 3 above the specific size. [Explanation of symbols]

[0054] 1 Algae culture device 2 Culture solution 3 Algae 10 Culture tank 10A culture tank 10B Culture tank 10C culture tank 11 Algae feeding device 12 light source 13 Mixing device 20 Algae transfer device 20A algae transfer device 20B Algae transfer device 20C algae transfer device 21 Conveyor Belt 21a Conveyor Belt 21b Conveyor Belt 21c Conveyor Belt 30 Recovery and dewatering tank 40 Concentration measuring device 41 Control device 50 Water quality control equipment 51 First Channel 51a First valve 52 Second Channel 52a Second valve 53 Third Channel 53a Third valve 100 tanks 101 Partition member

Claims

1. a plurality of culture tanks for culturing algae in a culture solution; an algae transfer device that connects the plurality of culture tanks and sequentially transfers the algae from the upstream culture tank to the downstream culture tank; The algae transfer device separates the algae of a certain size or less from the culture solution and transfers the algae. Algae culture device.

2. The algae transfer device includes a conveyor belt having openings of the specific size formed therein. The algae culture apparatus according to claim 1 .

3. Among the plurality of culture tanks, the conveyor belt provided in the upstream culture tank has a smaller mesh size than the conveyor belt provided in the downstream culture tank. The algae culture apparatus according to claim 2 .

4. The conveyor belt is formed with protrusions that scoop up the algae from the culture solution. The algae culture apparatus according to claim 2 or 3.

5. a concentration measuring device for measuring the concentration of the algae; A control device that drives the algae transfer device based on the measurement results of the concentration measurement device. The algae culture apparatus according to any one of claims 1 to 3.

6. a light source that irradiates the culture solution with light, the concentration measuring device measures the concentration of the algae based on the intensity of the light transmitted through the culture solution. The algae culture apparatus according to claim 5.

7. An agitation device is provided that agitates the culture solution and suspends the algae in the culture solution. The algae culture apparatus according to any one of claims 1 to 3.

8. The plurality of culture tanks are formed by partitioning the inside of a single tank. The algae culture apparatus according to any one of claims 1 to 3.

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