Patent Publication Number: US-2023151315-A1

Title: Compound algae culture apparatus

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims the benefit of priority to Taiwan Patent Application No. 110213640, filed on Nov. 18, 2021. The entire content of the above identified application is incorporated herein by reference. 
     Some references, which may include patents, patent applications and various publications, may be cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference. 
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to a compound algae culture apparatus, and more particularly to a compound algae culture apparatus that combines an enclosed photobioreactor and a growth regulating tank and being suitable for usages such as mass culturing. 
     BACKGROUND OF THE DISCLOSURE 
     Algae can effectively utilize light energy, carbon dioxide, water and inorganic salts to synthesize proteins, fats, carbohydrates and bioactive substances having high additional values. Due to having high efficiency in converting and utilizing light as nutrients, the algae shows stronger growth potential than advanced plants, such that algae cultivation is generally regarded as having significant importance. 
     Conventionally, a large-scale industrial production of algae mostly uses an open pond. However, this manner of production takes up too much space, has an unstable yield, and incurs high costs. Moreover, the open pond is easily polluted, light received by the algae is uneven, and a light energy utilization rate is not high. Due to different growth environments, growth conditions of the algae cannot be easily controlled, thereby resulting in death of the algae in a large scale and a low culture efficiency. In order to overcome the shortcomings of the open pond, the industry has developed an enclosed type photobioreactor culturing technology. In this type of culturing technology, the algae is cultivated in an enclosed light-transmitting pipe reactor or an enclosed reactor tank, and light is provided to the enclosed reactor or the enclosed reactor tank through an artificial light source or a natural light source, so that the algae can carry out photosynthesis and grow in an enclosed environment. Such an enclosed type culture apparatus (which utilizes photosynthesis) can save space, but has problems of being expensive and having difficulty in controlling the growth conditions. Further, an enclosed system is prone to problems such as dead algae and blockage. More importantly, the reactor or the reaction tank has a limited capacity, which can result in a low yield, high cultivation costs, difficulty in controlling the quality of the algae, and an inability to cultivate multiple types of algae at the same time. 
     Based on the above reasons, a conventional algae culture system has certain disadvantages. Therefore, how to redesign the algae culture system through an automatic control of an intelligent system and achieve an improvement via redesigning various factors and structures, so as to overcome the abovementioned deficiencies, has become one of the important issues to be addressed in the relevant industry. 
     SUMMARY OF THE DISCLOSURE 
     In response to the above-referenced technical inadequacies, the present disclosure provides a compound algae culture apparatus to overcome problems of a conventional algae culture apparatus. The conventional algae culture apparatus takes up space, is high in costs, and has difficulty in controlling growth conditions, such that the conventional algae culture apparatus is unfit for an industrial production. 
     In one aspect, the present disclosure provides a compound algae culture apparatus. The compound algae culture apparatus includes a photobioreactor module, a growth regulating module, and an automatic harvesting device. The photobioreactor module includes at least one photobioreactor unit. The at least one photobioreactor unit includes a light-transmitting coiled pipe, and the light-transmitting coiled pipe has a fluid inlet end and a fluid outlet end. The growth regulating module includes at least one growth tank unit. The at least one growth tank unit has a tank body. The tank body has a growth tank inlet and a growth tank outlet, and a plurality of partitions are disposed in the tank body to divide an inside of that tank body for formation of a curved flow channel. A volume of the at least one growth tank unit is configured to be larger than a volume of the at least one photobioreactor unit, and a residence time of a culture fluid in the at least one growth tank unit is not less than a residence time of the culture fluid in the at least one photobioreactor unit. The automatic harvesting device is connected to the growth tank outlet of the at least one growth tank unit. The automatic harvesting device is used for harvesting a portion of algae in the culture fluid. The culture fluid for culturing the algae enters the growth regulating module after carrying out photosynthesis in the photobioreactor module, the culture fluid passes through the automatic harvesting device after passing through the growth regulating module, and the culture fluid re-enters the photobioreactor module after the portion of the algae in the culture fluid is harvested by the automatic harvesting device. 
     Therefore, in the compound algae culture apparatus provided by the present disclosure, a photobioreactor unit of a pipeline type is combined with a growth tank unit that has a capacity several times greater than a capacity of the photobioreactor unit. Since the photobioreactor unit of a pipeline type has a strong photosynthesis reaction, and the growth tank has a large capacity and allows the growth of the algae to be regulated, a yield and a quality of the algae can be improved. 
     These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments may be better understood by reference to the following description and the accompanying drawings, in which: 
         FIG.  1    is a schematic diagram of a compound algae culture apparatus according to a first embodiment of the present disclosure; 
         FIG.  2    is a schematic cross-sectional diagram showing configurations of an oxygen discharge cylinder and a fluid inlet port of an oxygen discharge device according to the first embodiment of the present disclosure; 
         FIG.  3    is a block diagram of a compound algae culture apparatus according to a second embodiment of the present disclosure; 
         FIG.  4    is a schematic diagram of a photobioreactor unit according to the second embodiment of the present disclosure; 
         FIG.  5    is a schematic diagram of a growth tank unit according to the second embodiment of the present disclosure; 
         FIG.  6    is a block diagram showing a connection relationship of a control module and each component in the compound algae culture apparatus according to the present disclosure; and 
         FIG.  7    is a schematic diagram showing the photobioreactor unit and the growth tank unit in the compound algae culture apparatus of the present disclosure being connected to an external circulation device for a mixed culture of algae. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     The present disclosure is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Like numbers in the drawings indicate like components throughout the views. As used in the description herein and throughout the claims that follow, unless the context clearly dictates otherwise, the meaning of “a”, “an”, and “the” includes plural reference, and the meaning of “in” includes “in” and “on”. Titles or subtitles can be used herein for the convenience of a reader, which shall have no influence on the scope of the present disclosure. 
     The terms used herein generally have their ordinary meanings in the art. In the case of conflict, the present document, including any definitions given herein, will prevail. The same thing can be expressed in more than one way. Alternative language and synonyms can be used for any term(s) discussed herein, and no special significance is to be placed upon whether a term is elaborated or discussed herein. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms is illustrative only, and in no way limits the scope and meaning of the present disclosure or of any exemplified term. Likewise, the present disclosure is not limited to various embodiments given herein. Numbering terms such as “first”, “second” or “third” can be used to describe various components, signals or the like, which are for distinguishing one component/signal from another one only, and are not intended to, nor should be construed to impose any substantive limitations on the components, signals or the like. 
     First Embodiment 
     Referring to  FIG.  1    and  FIG.  2   , an embodiment of the present disclosure provides a compound algae culture apparatus. The compound algae culture apparatus includes a photobioreactor module  1 , a growth regulating module  2 , an automatic harvesting device  57 , and an oxygen discharge device  80 . The photobioreactor module  1  includes at least one photobioreactor unit  10 , and the growth regulating module  2  includes at least one growth tank unit  20 . The at least one photobioreactor unit  10  includes a light-transmitting coiled pipe  11 , the light-transmitting coiled pipe  11  has a fluid inlet end  111  and a fluid outlet end  112 , and the light-transmitting coiled pipe  11  is made of a transparent pipe (e.g., a glass pipe or an acrylic pipe). A culture fluid for culturing algae can enter the light-transmitting coiled pipe  11  from the fluid inlet end  111  and pass through the light-transmitting coiled pipe  11  at a steady flow rate. 
     A replenishment port  113  can also be disposed on an upper end of the light-transmitting coiled pipe  11 , and the replenishment port  113  is provided for an operator to add a new culture fluid or nutrients required for culturing the algae, or to inject carbon dioxide into the light-transmitting coiled pipe  11 . The photobioreactor unit  10  can also include multiple fill light devices  13 . The fill light devices  13  can be dimmable LED lighting devices, and can generate lights of different wavelengths according to the requirements for cultivating different algae species, so as to improve photosynthesis of the algae. 
     The at least one growth tank unit  20  is connected to the fluid outlet end  112  of the photobioreactor unit  10 , and the growth tank unit  20  has a tank body  21 . In this embodiment, the tank body  21  is a rectangular tank body. The tank body  21  of the at least one growth tank unit  20  has a growth tank inlet  211  and a growth tank outlet  212 , and a plurality of partitions  213  that are arranged in a staggered manner are disposed in each tank body  21 , so that an internal space of the tank body  21  is divided by the plurality of partitions  213  for formation of a curved flow channel  214 . In this way, a flow distance of the culture fluid inside the tank body  21  is increased, and a flow time is prolonged. 
     Particularly, in the present disclosure, a volume of the tank body  21  of the at least one growth tank unit  20  is arranged to be larger than a volume of the at least one photobioreactor unit  10 , and a residence time of the culture fluid in the at least one growth tank unit  20  is not less than a residence time of the culture fluid in the at least one photobioreactor unit  10 . In one exemplary embodiment of the present disclosure, the volume of the tank body  21  is arranged to be several times larger than the volume of the photobioreactor unit  10 , so that an amount of the culture fluid that can be contained in the growth tank unit  20  is several times greater than an amount of the culture fluid that can be contained in the photobioreactor unit  10 . Accordingly, a production capacity and a production efficiency can be effectively enhanced. 
     When the culture fluid enters the tank body  21 , the culture fluid can pass through the growth tank unit  20  at a slow flow rate, so that a temperature of the culture fluid can be gradually reduced, and an intensity of the photosynthesis can be reduced or stopped. Therefore, the algae has sufficient time to recover from damages of rapid growth and cell division (which are caused by the photosynthesis), and to digest nutrients obtained in the previous photosynthesis process, such that the algae is grown to a certain size before further division. 
     The automatic harvesting device  57  is connected to the growth tank outlet  212  of the growth tank unit  20 . A harvesting pipe  571  is disposed on the growth tank outlet  212  of the growth tank unit  20 , and a harvesting control valve  5711  is disposed on the harvesting pipe  571 . The culture fluid discharged from the harvesting pipe  571  can pass through the automatic harvesting device  57 , and a portion of the algae in the culture fluid can be harvested through the automatic harvesting device  57 . In this embodiment, the automatic harvesting device  57  includes a filter assembly  572  and a culture fluid holding tank  573 , and the culture fluid enters the culture fluid holding tank  573  after passing through the filter assembly  572 . The filter assembly  572  has pores of appropriate sizes, so that the algae in the culture fluid having a diameter larger than a diameter of the pores of the filter assembly  572  can be blocked by the filter assembly  572 . 
     In particular, the automatic harvesting device  57  of the present disclosure only harvests a certain percentage of the algae in the culture fluid during a harvesting procedure, so that the algae is partially retained in the culture fluid that passes through the automatic harvesting device  57 . In addition, a concentration of the algae retained in the culture fluid can be adjusted by controlling the harvesting percentage of the algae, so as to create environmental conditions suitable for the growth of the algae. In this way, the productivity and algae production quality of the compound algae culture apparatus of the present disclosure can be increased. 
     The automatic harvesting device  57  further includes an outlet pipe  574 , which is connected to an outlet of the culture fluid holding tank  573 . The outlet pipe  574  is connected to a pressurized transfer device  575 , which is a pressurized pump, and an outlet end of the pressurized transfer device  575  is connected to an oxygen discharge cylinder inlet pipe  811  of the oxygen discharge device  80 . Through the pressurized transfer device  575 , the culture fluid discharged from the automatic harvesting device  57  can be transported into the oxygen discharge device  80 , so that excessive oxygen of the culture fluid is discharged from the oxygen discharge device  80  to reduce an oxygen content of the culture fluid. 
     In this embodiment, the oxygen discharge device  80  includes an oxygen discharge cylinder  81 , and a liquid collection cylinder  82  connected to a bottom of the oxygen discharge cylinder  81 . The oxygen discharge cylinder  81  is cylindrical-shaped. The oxygen discharge cylinder  81  includes an oxygen discharge pipe  84  arranged at a center of the oxygen discharge cylinder  81 , and a hollow pipe  85  sleeved onto an outer side of the oxygen discharge pipe  84 . The liquid collection cylinder  82  is connected to the bottom of the oxygen discharge cylinder  81 , and a diameter of a junction between the oxygen discharge cylinder  81  and the liquid collection cylinder  82  is decreased to form a connecting neck between the oxygen discharge cylinder  81  and the liquid collection cylinder  82 . A lower end of the oxygen discharge pipe  84  passes through the connecting neck and extends into an upper part of the liquid collecting cylinder  82 , and an expansion section  841  is formed at the lower end of the oxygen discharge pipe  84 . 
     A diameter of the hollow pipe  85  is larger than that of the oxygen discharge pipe  84 , a lower end of the hollow pipe  85  extends to a location near a lower end that is inside the oxygen discharge cylinder  81 , and an upper section of the oxygen discharge pipe  84  is fitted into an inside of the hollow pipe  85 . An upper end of the hollow pipe  85  extends outside of an upper end of the oxygen discharge cylinder  81 , and the upper end of the hollow pipe  85  is connected to a gas extracting device  88  through an air suction pipe  812 . 
     A fluid inlet port  83  is formed on one side of the oxygen discharge cylinder  81 , and the fluid inlet port  83  is connected to the oxygen discharge cylinder inlet pipe  811 , so that the culture fluid can enter the fluid inlet port  83  through the oxygen discharge cylinder inlet pipe  811  and be delivered into the oxygen discharge cylinder  81  through the fluid inlet port  83 . A height of the fluid inlet port  83  is configured to be higher than heights of openings of the lower end of the oxygen discharge pipe  84  and a lower end of the hollow pipe  85 , so that the culture fluid sprayed from the fluid inlet port  83  is not suctioned into the hollow pipe  85  and the oxygen discharge pipe  84 . 
     As shown in  FIG.  2   , in this embodiment, a diameter of the fluid inlet port  83  that is connected to one end of the oxygen discharge cylinder  81  is decreased, so that the fluid inlet port  83  is formed into a nozzle. Further, a central axis of the fluid inlet port  83  is parallel to a tangential direction of a circumferential section of the oxygen discharge cylinder  81 , or an included angle of less than 90 degrees is formed therebetween. Therefore, a flow rate of the culture fluid that enters the oxygen discharge cylinder  81  is accelerated, and after the culture fluid contacts an inner wall of the oxygen discharge cylinder  81 , the culture fluid can flow in a spiral manner along the inner wall of the oxygen discharge cylinder  81  to the liquid collection cylinder  82  below the oxygen discharge cylinder  81 . 
     When the culture fluid is in a process of flowing from the oxygen discharge cylinder  81  into the liquid collection cylinder  82 , gas contained in the culture fluid can be discharged into the oxygen discharge cylinder  81  and the liquid collection cylinder  82 , and then be pumped out by the oxygen discharge pipe  84  and the hollow pipe  85 . Furthermore, in this process, dead algae in the culture fluid is separated from the culture fluid, extracted by vacuum suction generated by the gas extracting device  88 , and discharged into a collection container  882  through a discharge pipe  881 . Through the above configuration, an amount of the dead algae in the culture fluid can be decreased, thereby preventing the dead algae from sticking to a flow channel of the overall pipeline or the tank body  21  and causing blockage. Further, algae products produced in this manner do not have an unpleasant odor generated by the dead algae. Instead, the algae products are imbued with the aroma of natural algae, so that the purpose of improving product quality is achieved. 
     The liquid collection cylinder  82  is connected to the bottom of the oxygen discharge cylinder  81  for accommodating the culture fluid flowing down from the oxygen discharge cylinder  81 , and a side exhaust port  821  is disposed on one side of the upper part of the liquid collection cylinder  82 . A bottom of the liquid collection cylinder  82  is connected to a bottom of the buffer tank  86  through a connection pipe  87 , so that the culture fluid in the liquid collection cylinder  82  flows into the buffer tank  86  through the connecting pipe  87 . The buffer tank  86  serves as a buffer space for the culture fluid to enter the photobioreactor unit  10 . The culture fluid flown from the oxygen discharge device  80  first enters the buffer tank  86 , and then enters the photobioreactor unit  10  from the buffer tank  86 , so that the algae in the culture fluid once again carries out the photosynthesis. 
     Second Embodiment 
     Referring to  FIG.  3    to  FIG.  7   , a second embodiment of the present disclosure provides a compound algae culture apparatus  100 . It should be noted that technical details of this embodiment are similar to those of the first embodiment, and the similarities therebetween will not be reiterated herein. 
     The compound algae culture apparatus  100  of this embodiment includes: a photobioreactor module  1 , a growth regulating module  2 , a circulation transfer module  3 , a circulation pipeline module  4 , a growth monitoring and regulating module  5 , and a control module  6 . 
     As shown in  FIG.  4   , the photobioreactor module  1  includes a plurality of photobioreactor units  10 . In this embodiment, each of the photobioreactor units  10  includes: a light-transmitting coiled pipe  11 , a growth monitoring sub-module  12 , a fill light device  13 , a shading device  14 , a photobioreactor temperature control device  15 , a first inlet bypass connector  16 , and a first outlet bypass connector  17 . 
     As shown in  FIG.  4   , the light-transmitting coiled pipe  11  can further have a pressure control valve  114  disposed thereon, so that a pressure of the culture fluid of each of the photobioreactor units  10  can be regulated to be suitable for the growth of the algae. In this embodiment, the growth monitoring sub-module  12  of each of the photobioreactor units  10  includes an illuminance sensor  121 , a temperature sensor  122 , a pressure sensor  123 , a gas concentration sensor  124 , and a nutrient concentration sensor  125 , so as to monitor growth condition parameters of each of the photobioreactor units  10 . The growth condition parameters can include a light intensity, a temperature, a pressure, an oxygen or carbon dioxide concentration, and a nutrient concentration. 
     As shown in  FIG.  4   , the shading device  14  of the photobioreactor unit  10  is a sunshade arranged above the light-transmitting coiled pipe  11 . An intensity of light that is received by the light-transmitting coiled pipe  11  can be controlled by an opening degree of the shading device  14 . 
     As shown in  FIG.  4   , in this embodiment, the photobioreactor temperature control device  15  includes: an inlet heat exchanger  151  disposed at the fluid inlet end  111  of the photobioreactor unit  10 , an inlet heater  152  disposed at an inlet of the light-transmitting coiled pipe  11 , or pipeline heaters  153  disposed at suitable locations of the light-transmitting coiled pipe  11 . The photobioreactor temperature control device  15  can be used in cooperation with a water sprinkler and other types of cooling devices to control the temperature of the culture fluid in each of the photobioreactor units  10 . The temperature of the culture fluid in each of the photobioreactor units  10  can be adjusted to a temperature suitable for algae growth. 
     As shown in  FIG.  3   , the first inlet bypass connector  16  and the first outlet bypass connector  17  of each of the photobioreactor units  10  are disposed at the fluid inlet end  111  and the fluid outlet end  112  of the light-transmitting coiled pipe  11 , respectively. Therefore, when one of the photobioreactor units  10  is to be cleaned or used for a mixed culture of another species of algae, the first inlet bypass connector  16  and the first outlet bypass connector  17  can be connected to pipelines of an external circulation device  7  that is used for cleaning pipelines of the photobioreactor units  10  or performing the mixed culture. 
     As shown in  FIG.  3    and  FIG.  5   , in this embodiment, the growth regulating module  2  includes a plurality of growth tank units  20  that correspond to the plurality of photobioreactor units  10 . The growth tank units  20  of the growth regulating module  2  are connected to the plurality of photobioreactor units  10  of the photobioreactor module  1  through the circulation pipeline module  4 . Furthermore, the culture fluid can be circulated between the plurality of photobioreactor units  10  and the plurality of growth tank units  20  under the control of the circulation transfer module  3  and the circulation pipeline module  4 . 
     As shown in  FIG.  5   , each of the growth tank units  20  includes a tank body  21 , a growth tank light source device  22 , a growth tank gas replenishment device  23 , a growth tank temperature control device  24 , a fluid agitating device  25 , a second inlet bypass connector  26 , and a second outlet bypass connector  27 . The tank body  21  of each of the growth tank units  20  has a growth tank inlet  211  and a growth tank outlet  212 , and the culture fluid enters the tank body  21  through the growth tank inlet  211  and exits through the growth tank outlet  212 . A plurality of partitions  213  that are arranged in a staggered manner are disposed in the tank body  21 , so that an internal space of the tank body  21  is separated by the plurality of partitions  213  to form a curved flow channel  214 . 
     As shown in  FIG.  5   , the growth tank light source device  22  of each of the growth tank units  20  is disposed above the tank body  21  to regulate a light intensity of light received by the culture fluid in the growth tank unit  20 . The growth tank gas replenishment device  23  can be disposed in the tank body  21  and includes a gas conduit, and the growth tank gas replenishment device  23  is connected to a gas pump  533 , so that the gas pump  533  fills gas (e.g., carbon dioxide or oxygen) into the growth tank gas replenishment device  23 . Then, the gas is injected into the culture fluid in the tank body  21  through air holes of the growth tank gas replenishment device  23 . The growth tank temperature control device  24  can be a heater, a heat exchanger, or other temperature control devices disposed in the tank body  21  for regulating the temperature of the culture fluid in the tank body  21 . In one exemplary embodiment of the present disclosure, multiple ones of the growth tank temperature control device  24  are disposed at different locations within the tank body  21  for controlling the temperature of the culture fluid at the different locations within the tank body  21 . Furthermore, in the tank body  21 , the fluid agitating device  25  agitates and drives a water flow to prevent the algae from settling on a tank bottom and resulting in a reduced growth rate. The fluid agitating device  25  can be a motor-driven propeller, or an agitator, a waterwheel, a pump, a wave maker, or other types of devices that can be used to increase a flow rate of the culture fluid or create the water flow. The fluid agitating device  25  is used to form a water flow for which the culture fluid inside the tank body  21  flows from the growth tank inlet  211  of the tank body  21  toward the growth tank outlet  212 , thereby allowing the culture fluid inside the tank body  21  to be maintained in a flowing state. Therefore, the algae in the culture fluid can be prevented from precipitating or sticking to an inner side wall of the tank body  21 , and a situation in which the culture fluid does not flow sufficiently (which can cause the algae in the culture fluid to be in contact with the growth tank temperature control device  24  for too long such that the algae is overheated and becomes the dead algae, or sticks to the growth tank temperature control device  24 ) can be avoided. 
     As shown in  FIG.  5   , in the present disclosure, the growth tank temperature control devices  24  can be disposed at locations adjacent to a position above the growth tank gas replenishment device  23 , so that gas bubbles formed in the culture fluid through the growth tank gas replenishment device  23  can allow the culture fluid around each of the growth tank temperature control devices  24  to flow more completely. Furthermore, in the embodiment shown in  FIG.  3   , although the fluid agitating device  25  is only shown to be disposed at the growth tank inlet  211  of the tank body  21 , the present disclosure is not limited thereto. In other embodiments of the present disclosure not shown in the figures, one fluid agitating device  25  can be disposed in the rear of each of the growth tank temperature control devices  24 , such that a better flow agitating effect can be achieved. Therefore, precipitation of the algae in the culture fluid can be avoided, and the situation in which the algae in the culture fluid becomes dead algae due to being in contact with the growth tank temperature control device  24  for too long can also be prevented. Moreover, contact between carbon dioxide and the algae in the culture liquid can be increased, and the algae can receive sufficient illuminance. 
     As shown in  FIG.  5   , the second inlet bypass connector  26  and the second outlet bypass connector  27  of each of the growth tank units  20  are connected to the growth tank inlet  211  and the growth tank outlet  212  of the tank body  21 , respectively. Therefore, when each of the growth tank units  20  is to be cleaned or temporarily used for a mixed culture of another species of algae (as shown in  FIG.  5   ), the second inlet bypass connector  26  and the second outlet bypass connector  27  can be connected to the pipelines of the external circulation device  7  that is used for cleaning pipelines of the growth tank units  20  or performing the mixed culture. 
     In addition, as shown in  FIG.  3    and  FIG.  5   , each of the growth tank units  20  can also have a nutrient supply bottle  215  disposed thereon. The nutrient supply bottle  215  is connected to a gas distribution pipe  534 , and the nutrient supply bottle  215  can be controlled by air pressure to transport supplemental materials into the growth tank unit  20 , or to sample the culture fluid from the growth tank unit  20  for nutrient replenishment, gas addition, sample investigation, etc. When the growth tank unit  20  is used for a mixed culture of different species of algae, each of the growth tank units  20  can have a dedicated nutrient supply bottle  215  for replenishing dedicated nutrition and gas, so as to ensure that the growth tank unit  20  is not contaminated. 
     In addition, as shown in  FIG.  5   , the growth regulating module  2  can further include a growth tank feeding device  59  that is simultaneously connected to the plurality of growth tank units  20  through the pipelines. The growth tank feeding device  59  can be used to uniformly replenish supplements (such as gas and nutrients) for each of the growth tank units  20 , and can be used to store nutrients or supplements required for cultivating different algae species. 
     As shown in  FIG.  3   , the circulation transfer module  3  is connected to the photobioreactor module  1  and the growth regulating module  2  through the circulation pipeline module  4 , so that the circulation transfer module  3  can be used to transport the culture fluid. Through the connection of the circulation pipeline module  4 , the culture fluid is allowed to flow in the plurality of photobioreactor units  10  of the photobioreactor module  1  and the plurality of growth tank units  20  of the growth regulating module  2 . 
     As shown in  FIG.  3   , in this embodiment, the circulation transfer module  3  includes a main circulation pump  31  and auxiliary pumps  32  that are scattered and disposed at different locations of the circulation pipeline module  4 . The main circulation pump  31  is disposed on a pipeline of the circulation pipeline module  4  between the photobioreactor module  1  and the growth regulating module  2 , and is used to pressurize the culture fluid into the pipeline of the circulation pipeline module  4 , so as to provide the pressure required for the culture fluid to flow in the circulation pipeline module  4 . 
     As shown in  FIG.  3   , the circulation pipeline module  4  is used to connect the circulation transfer module  3 , the plurality of photobioreactor units  10  of the photobioreactor module  1 , and the plurality of growth tank units  20  of the growth regulating module  2 . In this embodiment, the circulation pipeline module  4  includes: a main pump outlet pipe  41 , a main pump inlet pipe  42 , a first inlet main pipe  43 , a plurality of first inlet connection pipes  431  connected to the first inlet main pipe  43 , a first outlet main pipe  44 , a plurality of first outlet connection pipes  441  connected to the first outlet main pipe  44 , a second inlet main pipe  45 , a plurality of second inlet connection pipes  451  connected to the second inlet main pipe  45 , a second outlet main pipe  46 , a plurality of second outlet connection pipes  461  connected to the second outlet main pipe  46 , and a connection pipeline  47 . 
     As shown in  FIG.  3   , the main pump outlet pipe  41  is connected to an outlet end  311  of the main circulation pump  31 , and the main pump inlet pipe  42  is connected to an inlet end  312  of the main circulation pump  31 . Furthermore, the main pump outlet pipe  41  has a main pump inlet control valve  411  disposed thereon, and the main pump inlet pipe  42  has a main pump inlet control valve  421  disposed thereon. The main pump outlet pipe  41  is connected to the first inlet main pipe  43 , the first inlet main pipe  43  is connected to the fluid inlet ends  111  of the plurality of photobioreactor units  10  through the plurality of first inlet connection pipes  431 , and the first outlet main pipe  44  is connected to the fluid outlet ends  112  of the plurality of photobioreactor units  10  through the plurality of first outlet connection pipes  441 , so that the plurality of photobioreactor units  10  are connected in parallel between the first inlet main pipe  43  and the first outlet main pipe  44 . 
     As shown in  FIG.  3   , an outlet end of the first outlet main pipe  44  is connected to an inlet end of the main pump inlet pipe  42  and an inlet end of the second inlet main pipe  45 . The second inlet main pipe  45  is connected to the growth tank inlets  211  of the plurality of growth tank units  20  through the plurality of second inlet connection pipes  451 , and the second outlet main pipe  46  is connected to the growth tank outlets  212  of the plurality of growth tank units  20  through the plurality of second outlet connection pipes  461 . Therefore, the plurality of growth tank units  20  are connected in parallel between the second inlet main pipe  45  and the second outlet main pipe  46 . One end of the second outlet main pipe  46  away from the plurality of growth tank units  20  is connected to the main pump inlet pipe  42  at a location between the main pump inlet control valve  421  and the inlet end  312  of the main circulation pump  31 . 
     As shown in  FIG.  3   , each of the first inlet connection pipes  431  has a first inlet control valve  4311  disposed thereon, and each of the first outlet connection pipes  441  has a first outlet control valve  4411  disposed thereon. Furthermore, each of the second inlet connection pipes  451  has a second inlet control valve  4511  disposed thereon, and each second outlet connection  461  has a second outlet control valve  4611  disposed thereon. When the first inlet control valve  4311  and the first outlet control valve  4411  corresponding to any one of the photobioreactor units  10  are closed, the culture fluid cannot pass through the photobioreactor unit  10 , such that the photobioreactor unit  10  is in a closed state. Similarly, when the second outlet control valve  4611  and the second inlet control valve  4511  corresponding to any one of the growth tank units  20  are closed, the culture fluid cannot pass through the growth tank unit  20 , such that the growth tank unit  20  is in a closed state. 
     As shown in  FIG.  3   , the first inlet control valve  4311  of each of the photobioreactor units  10  is disposed on a location of the first inlet connection pipe  431  (that corresponds to each of the photobioreactor units  10 ) between the first inlet bypass connector  16  and the first inlet main pipe  43 , and the first outlet control valve  4411  of each of the photobioreactor units  10  is disposed on a location of the first outlet connection pipe  441  (that corresponds to each of the photobioreactor units  10 ) between the first outlet bypass connector  17  and the first outlet main pipe  44 . Similarly, the second inlet control valve  4511  of each of the growth tank units  20  is disposed on a location of the second inlet connection  451  (that corresponds to each of the growth tank units  20 ) between the second inlet bypass connector  26  and the second inlet main pipe  45 , and the second outlet control valve  4611  of each of the growth tank units  20  is disposed on a location of the second outlet connection  461  (that corresponds to each of the growth tank units  20 ) between the second outlet bypass connector  27  and the second outlet main pipe  46 . 
     Therefore, as shown in  FIG.  7   , when any of the photobioreactor unit  10  or the growth tank unit  20  is to be cleaned or used for a mixed culture of different species of algae, the first inlet control valve  4311  and the first outlet control valve  4411  of the photobioreactor unit  10  can be closed, and the second inlet control valve  4511  and the second outlet control valve  4611  of the growth tank unit  20  can closed, so as to prevent cleaning water or the culture fluid for the mixed culture of other species of algae from entering into the circulation pipeline module  4  and causing contamination of the culture fluid in the circulation pipeline module  4  and other components of the compound algae culture apparatus. 
     As shown in  FIG.  3   , the circulation pipeline module  4  can further control a circulation path of the culture fluid through the connection pipeline  47  and a plurality of flow control valves. The connection pipeline  47  is connected to one end of the first inlet main pipe  43  and one end of the first outlet main pipe  44  that are adjacent to the main circulation pump  31 , and two connection pipeline control valves  471  are disposed at two ends of the connection pipeline  47 , respectively. Furthermore, a first flow control valve  432  is disposed on a location of the first inlet main pipe  43  between the connection pipeline  47  and one of the first inlet connection pipes  431  that is most adjacent to the main circulation pump  31 . A second flow control valve  442  is disposed on a location of the first outlet main pipe  44  between the connection pipeline  47  and one of the first outlet connection pipes  441  that is most adjacent to the main circulation pump  31 . A third flow control valve  443  is disposed on a location of the first outlet main pipe  44  between the connection pipeline  47  and the main pump inlet pipe  42 . A fourth flow control valve  452  is disposed on a location of the second inlet main pipe  45  between the main pump inlet pipe  42  and one of the second inlet connection pipes  451  that is most adjacent to the main circulation pump  31 . A fifth flow control valve  462  is disposed on a location of the second outlet main pipe  46  between the main pump inlet pipe  42  and one of the second outlet connection pipes  461  that is most adjacent to the main circulation pump  31 . 
     As shown in  FIG.  3   , through the growth monitoring and regulating module  5 , the compound algae culture apparatus  100  can monitor the culture of the algae, control growth conditions of the algae, replenish the gas, nutrients, or algae seedlings required for algae growth according to requirements, monitor a growth status of the algae, and timely harvest the algae. In this embodiment, the growth monitoring and regulating module  5  includes: a monitoring module  51 , a main circulation temperature control device  52 , a feeding device  54 , a gas replenishment device  53 , an algae replenishment device  55 , an algae growth monitoring device  56 , the automatic harvesting device  57 , and the oxygen discharge device  80 . 
     As shown in  FIG.  3   , the monitoring module  51  is a sensor module that includes various types of sensors (e.g., a temperature sensor, a pressure sensor, a nutrient concentration sensor, a pH sensor, a carbon dioxide concentration sensor, and an oxygen concentration sensor). The monitoring module  51  is used to monitor a water temperature, a pH value, a content of dissolved oxygen, a nutrient concentration, a turbidity, a carbon dioxide concentration, an oxygen concentration, and other parameters of the culture fluid for algae cultivation. In this embodiment, the monitoring module  51  is connected to the main pump inlet pipe  42  and the main pump outlet pipe  41  through bypass pipes  511  and  512 , and bypass control valves  5111  and  5121  are respectively disposed on the bypass pipes  511  and  512  to control a flow amount of the culture fluid that passes through the monitoring module  51  via the bypass pipes  511  and  512 . In addition, the monitoring module  51  is connected to a drain valve  513  for sampling the culture fluid for inspection and analysis. 
     As shown in  FIG.  3   , the main circulation temperature control device  52  can be a heat exchanger, a heater, or a cooler. In this embodiment, the main circulation temperature control device  52  is connected between the first outlet main pipe  44  and the second inlet main pipe  45  via bypass pipes  521  and  522 , and bypass control valves  5211  and  5221  are disposed on the bypass pipes  521  and  522 , respectively. Furthermore, in this embodiment, the third flow control valve  443  is disposed between the bypass pipe  521  and the bypass pipe  522 . As such, when the third flow control valve  443  is closed and the bypass control valves  5211  and  5222  are opened, the culture fluid can flow through the main circulation temperature control device  52 , so that the temperature of the culture fluid can be adjusted. 
     As shown in  FIG.  3   , the feeding device  54  is connected to the main pump inlet pipe  42  through a supply pipe  541 , and the supply pipe  541  has a supply control valve  5411  disposed thereon. The feeding device  54  can be used to replenish the nutrients in the culture fluid, add chemicals to adjust the pH value of the culture fluid, or replenish nutrients required for the growth of other species of algae. The gas replenishment device  53  is connected to the main pump inlet pipe  42  through a gas replenishment pipe  531 , and the gas replenishment pipe  531  has a gas control valve  5311  disposed thereon. In this embodiment, the gas replenishment device  53  also includes a second gas replenishment pipe  532 , and the second gas replenishment pipe  532  is connected to a gas pump  533 . Through the gas distribution pipe  534 , the gas pump  533  is further connected to the growth tank gas replenishment devices  23  of the growth tank units  20  of the growth regulating module  2 . The gas replenishment device  53  can be used to provide carbon dioxide or oxygen, so that the carbon dioxide or oxygen can be replenished when the carbon dioxide or oxygen concentration in the culture fluid is insufficient. 
     As shown in  FIG.  3   , the algae replenishment device  55  is connected to the supply pipe  541  through an algae supply pipe  551 , and an algae supply control valve  5511  is disposed on the algae supply pipe  551  for controlling the algae supply pipe  551  to be opened or closed. The algae replenishment device  55  is used to replenish the algae seedlings or the algae that is cultivated into the culture fluid, so as to adjust a density of the algae in the culture fluid. The algae growth monitoring device  56  is disposed between the main pump outlet pipe  41  and the first inlet main pipe  43 . The algae growth monitoring device  56  can monitor the growth status of the algae (which includes information such as the density of the algae, a color of the algae, and a growth size of the algae) in the culture fluid through optical means. The automatic harvesting device  57  is connected between the main pump outlet pipe  41  and the first inlet main pipe  43  through the harvesting pipe  571 . The automatic harvesting device  57  can work in conjunction with the algae growth monitoring device  56 . When the algae growth monitoring device  56  detects that the density and the growth size of the algae in the culture fluid meet harvesting conditions, the automatic harvesting device  57  can begin harvesting the algae. 
     As shown in  FIG.  3   , in this embodiment, the oxygen discharge device  80  is disposed on the main pump inlet pipe  42 . After the culture fluid passes through the photobioreactor module  1  and the growth regulating module  2  but before the culture fluid is recirculated to the inlet end  312  of the main circulation pump  31 , the culture fluid can first enter the oxygen discharge device  80 , so that the excessive oxygen and the dead algae in the culture fluid are removed. 
     As shown in  FIG.  6   , the compound algae culture apparatus  100  of the present disclosure further includes the control module  6 . In this embodiment, the control module  6  is coupled to the photobioreactor module  1 , the growth regulating module  2 , the circulation transfer module  3 , the circulation pipeline module  4 , and the growth monitoring and regulating module  5 . The control module  6  can be a central control computer or an information device capable of remote control, and remote controlling in the present disclosure can also be achieved by using the Internet and applications on a smartphone. The control module  6  can be used to receive parameters or monitoring data detected by the aforementioned sensors, and to control the various control valves of the circulation pipeline module  4  and various sub-modules or devices of the monitoring module  51 . In this way, an operation of the compound algae culture apparatus  100  can be controlled, thereby achieving purposes of monitoring the growth conditions of the algae, automatically replenishing or adjusting parameters of the growth conditions of the algae, and automatically harvesting the algae. 
     Reference is made to  FIG.  7   , which shows a use mode in which the compound algae culture apparatus  100  of the present disclosure uses some of the photobioreactor units  10  and the growth tank units  20  for a mixed culture. In this embodiment, the first inlet control valve  4311  and the first outlet control valve  4411  corresponding to one of the photobioreactor units  10  are closed, and the second inlet control valve  4511  and the second outlet control valve  4611  corresponding to one of the growth tank units  20  are closed. Then, the external circulation device  7  is connected between the first inlet bypass connector  16  and the first outlet bypass connector  17  of the photobioreactor units  10  and the second inlet bypass connector  26  and the second outlet bypass connector  27  of the growth tank unit  20 , which allows the culture fluid to circulate and flow between the photobioreactor unit  10  and the growth tank unit  20  without flowing into the circulation pipeline module  4  (so as to prevent contamination of the culture fluid of the compound algae culture apparatus  100 ). 
     In more detail, the external circulation device  7  includes: a plurality of external hoses  71 , an external circulation pump  72 , an external temperature control device  73 , an external gas replenishment device  74 , and an external feeding device  75 . The plurality of external hoses  71  are connected between the first outlet bypass connector  17  of the photobioreactor unit  10  and the second inlet bypass connector  26  of the growth tank unit  20 , and between the second outlet bypass connector  27  and the first inlet bypass connector  16 . The external circulation pump  72 , the external temperature control device  73 , the external gas replenishment device  74 , and the external feeding device  75  are all connected to the plurality of external hoses  71 , so that the culture fluid can be circulated between the photobioreactor unit  10  and the growth tank unit  20  through the external circulation pump  72 . 
     Beneficial Effects of the Embodiments 
     One of the beneficial effects of the present disclosure is that, by virtue of “a photobioreactor unit of a pipeline type being combined with a growth tank unit that has a capacity several times greater than a capacity of the photobioreactor unit,” the photobioreactor unit of a pipeline type has a strong photosynthesis reaction, and the growth tank has a large capacity and allows the growth of the algae to be regulated, thereby a yield and a quality of the algae can be improved. 
     Another beneficial effect of the present disclosure is that, the compound algae culture apparatus of the present disclosure can be connected to the photobioreactor module, the growth regulating module, and the circulation transfer module through the circulation pipeline module. Hence, the compound algae culture apparatus of the present disclosure meets the requirements of an industrial mass production due to having the flexibility of easily increasing the production capacity. In addition, a set of main circulation pumps can work in cooperation with the circulation pipeline module to circulate the culture fluid between different photobioreactor units and different growth tank units. In this way, centralized control can be achieved, the structure can be simplified, and production costs can be reduced. 
     The foregoing description of the exemplary embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. 
     The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope.