Internal irradiation bioreactor

Abstract

An internally illuminated bioreactor and related algae production method are disclosed that uses a self-contained submerged culture light assembly configured to manage heat generated by light-emitting elements, such as light-emitting diodes ("LEDs") on the submerged culture light. The bioreactor includes an outer shell and one or more submerged culture light irradiators disposed within the outer shell and arranged along the outer periphery of a hollow inner tube. The light-emitting elements and inner tube are themselves housed within a preferably transparent outer tube of the irradiator, which allows light generated by the light-emitting elements to pass to the algae culture in the culture tank. A thermal management system is provided to cool the irradiators using forced air that flows through the hollow inner tube from the top to the bottom, then out an outlet at the bottom of the inner tube, and is directed upward by the buoyancy of the heated air, i.e., without the use of a mechanical air conditioner. As the air moves upward between the light-emitting elements and the outer tube, it further carries heat away from the light-emitting elements. The heated air is finally exhausted from the top of the irradiator. Preferably, each light irradiation device further includes a cleaning system that allows the outer surface of the light irradiation device's outer barrel to be automatically cleaned, thereby preventing newly formed algae from accumulating on the light irradiation device and ensuring a continuous flow of light from the device into the algae culture throughout algae production.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 028,705, entitled "Internally Illuminated Bioreactor," filed May 22, 2020, the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates generally to systems and methods for biomass production and harvesting, and more particularly to bioreactor systems and related methods for enhancing the production and harvesting of algae. [Background technology]

[0003] Demand for algae products has increased in recent years to the point where algae is becoming an important component of the supply chains for human and animal foods, pharmaceuticals and nutritional supplements, and vitamins. The inclusion of these supply chains means more stringent quality control and approval requirements. Algae producers need high-quality algae and the ability to cultivate it on an industrial scale.

[0004] Various systems and methods have been employed in attempts to cultivate algae for such applications. For example, efforts have been made to cultivate algae in outdoor shallow ponds or raceways. However, such outdoor cultivation systems require an excessively large geographic footprint, resulting in extremely low production per unit area to meet industrial-scale requirements. To maximize land utilization, resource management and resource efficiency dictate the use of large bioreactors or tanks rather than ponds or raceways. There are several reasons for this. Outdoor cultivation is limited by the ability of sunlight to penetrate to the bottom of shallow ponds. Outdoor ponds and raceways are typically less than 76 centimeters deep, with sunlight penetrating only the top few centimeters. Areas suitable for large-scale outdoor cultivation of algae are limited to a very limited number of locations on Earth. Furthermore, contamination is a constant threat, and wind, rain, and storms can force producers to discard cultures or restart the cultivation process. Not only does weather affect growth, potentially reducing productivity, but the length of daylight hours alone similarly limits the amount of sunlight a culture can receive. These challenges have prevented outdoor growers from producing consistent, predictable supplies of the large, industrial-scale quantities needed to meet the growing global demand for algae products.

[0005] Efforts have also been made to cultivate algae in indoor bioreactors. For example, indoor bioreactor systems consist of a series of sealed, transparent tubes that wind their way through large-scale facilities and are illuminated by one or more external growth lights; these systems also suffer from being unable to meet industrial-scale requirements. The limitations of current illumination technology can prevent the use of large tanks. As a result, current larger bioreactors are typically illuminated externally, with the growth lights typically positioned along the exterior of the transparent bioreactor or tube. When bioreactors or tanks are illuminated externally, light cannot penetrate the denser cultures. This limits the size and width of the bioreactor because algae in the interior regions of the bioreactor, which have extremely large diameters, cannot receive sufficient light from the external light source. Furthermore, the bioreactor material can vary or limit the amount of light reaching the algae culture, thereby limiting the effective size of such bioreactors. Furthermore, known indoor bioreactors typically include one or more glass cylinders that expose the algae culture to one or more culture lights located outside the cylinders. This configuration limits their scale to well below the industrial-scale capacity needed to meet the growing demand for algae production. Furthermore, cleaning indoor bioreactors presents additional challenges, as the cleaning process typically requires periodic interruptions to production.

[0006] In other cases where attempts have been made to use internal irradiation in bioreactors, such efforts have met with limited success. Even the use of internal irradiation assemblies poses increased challenges because heat generated by the irradiators can adversely affect both the temperature of the irradiators (and thus their overall efficiency and durability) and the temperature of the culture, necessitating complex cooling systems for such internal irradiators that are also not suitable for industrial scale-up.

[0007] Additionally, while there have been efforts to apply algae cultivation processes to greenhouse gas reduction and carbon capture and utilization, current approaches to algae cultivation are not scalable or efficient for such applications. More specifically, current outdoor approaches to greenhouse gas reduction are often costly and ineffective. Introducing aqueous CO2 requires costly prior solid-liquid separation and liquefaction processes, while introducing gaseous CO2 requires sufficient cultivation depth / altitude to adequately deliver CO2 to the algae culture. Shallow ponds simply cannot provide this depth. Additionally, current indoor approaches cannot be scaled to support stable algae cultivation 24 hours a day, 7 days a week, 365 days a year to consume large amounts of CO2, typically requiring interruptions to production for cleaning.

[0008] Thus, there remains a need in the art for bioreactor systems and related methods that facilitate the production and harvest of algae, which are necessary to meet current and future global demand for algae products, and which can readily produce algae on an industrial scale that, among other things, maximizes algae production for a given spatial footprint, using systems and methods that are less complex and more easily implemented than known bioreactor systems and methods. Summary of the Invention [Problem to be solved by the invention]

[0009] Disclosed herein is an internally illuminated bioreactor and related algae production method that avoids one or more of the drawbacks of prior art algae production systems and methods. According to certain aspects of one embodiment, an internally illuminated bioreactor with built-in submersible culture lights is provided that efficiently and effectively manages heat generated by light emitting elements, such as light emitting diodes ("LEDs"), on the submersible culture lights and ensures that the heat generated by these light emitting elements does not adversely affect the surrounding algae culture or the light emitting elements themselves. [Means for solving the problem]

[0010] In a particularly preferred embodiment, the internally illuminated bioreactor comprises an outer shell and one or more submerged cultivation light irradiators disposed within the outer shell, directing light from the irradiators into an algae culture tank within the shell. The irradiators preferably include an arrangement of vertical light-emitting elements, such as LED chip assemblies, arranged along the outer periphery of a hollow inner tube to project light into the tank and promote algae growth therein. The light-emitting elements and inner tube are themselves housed within a preferably transparent outer tube of the light-irradiation element, which allows light generated by the light-emitting elements to pass through to the algae culture in the tank. To prevent heat generated by the light-emitting elements from adversely affecting the algae culture in the tank, a thermal management system is provided that effectively cools the light-irradiation elements while minimizing the need for a combined air conditioning system. More specifically, forced air is directed through the hollow inner tube from the top to the bottom and then discharged from the inner tube through one or more exhaust ports at the bottom of the inner tube. The air is heated as it moves through the interior of the inner tube, thereby carrying heat away from the light-emitting element attached to the outer surface of the inner tube. After being discharged through such lower outlet of the inner tube, the heated air moves upward between the light-emitting element of the light-emitting device and the outer tube due to its buoyancy, without the need for any additional mechanical air conditioning device. As the air moves upward between the light-emitting element and the outer tube, it further carries heat away from the light-emitting element. The heated air is finally discharged from the top of the light-emitting device. Preferably, each light-emitting device further includes a cleaning system that enables automatic cleaning of the outer surface of the outer tube of the light-emitting device, thereby preventing newly formed algae from accumulating on the light-emitting device and ensuring a continuous flow of light from the device into the algae culture throughout algae production.

[0011] According to a specific aspect of one embodiment of the present invention, there is provided an internally irradiated bioreactor comprising: an outer shell; a light irradiation device within the outer shell, the light irradiation device outer shell configured to pass light from the light irradiation device into a culture tank within the shell; a light irradiation device inner shell having a first flow path extending from an upper portion of the light irradiation device to a lower portion of the light irradiation device and at least one outlet from the first flow path adjacent to the lower portion of the light irradiation device; a light irradiation device including a plurality of light-emitting elements arranged along the outer periphery of the inner shell; and a forced air source in fluid communication with the first flow path and supplying forced air to the first flow path, wherein a second flow path is defined between the plurality of light-emitting elements and the light irradiation device outer shell, and the second flow path receives heated air from the at least one outlet and delivers the heated air from the at least one outlet to the upper portion of the light irradiation device by buoyancy of the heated air.

[0012] According to a further aspect of one embodiment of the present invention, there is provided an internally illuminated bioreactor comprising: an outer shell defining an algae culture tank therein; an illumination device within the algae culture tank, the illumination device further comprising a plurality of light-emitting elements arranged along the periphery of the illumination device, a first air flow path extending from an upper portion of the illumination device to a lower portion of the illumination device, and a second air flow path extending from the lower portion of the illumination device to the upper portion of the illumination device; and a forced air source in fluid communication with the first air flow path and supplying forced air to the first air flow path, wherein the illumination device is configured to deliver air from the first air flow path through the second air flow path from the illumination device to an outlet without the use of a mechanical air conditioning device due to the buoyancy of the air in the second air flow path.

[0013] Further aspects, features, and advantages of the present invention will become readily apparent from the following detailed description, which merely illustrates certain specific embodiments and implementations, including the best mode contemplated for carrying out the invention. The present invention is also capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. [Brief explanation of the drawings]

[0014] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized. The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings, in which like reference numerals refer to like elements.

[0015] [Figure 1] FIG. 1 is a front perspective view of an internally irradiated bioreactor according to certain aspects of one embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view showing the components of the bioreactor elements of FIG. 1 that form the algae culture vessel. [Figure 3] FIG. 2 is a front perspective view of a light irradiation device used in the bioreactor of FIG. 1. [Figure 4] FIG. 4 is an exploded view of the light irradiation device of FIG. [Figure 5] 4 is a top perspective cross-sectional view of the light irradiation device of FIG. 3. [Figure 6] 4 is an enlarged perspective view showing a lower part of the light irradiation device of FIG. 3. FIG. [Figure 7] FIG. 4 is an enlarged perspective view showing an upper portion of the light irradiation device of FIG. [Figure 8] FIG. 2 is an enlarged perspective view of a lid assembly for use in the bioreactor of FIG. 1. [Figure 9] FIG. 2 is an exploded view of a cleaning system used in the bioreactor of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention can be understood by reference to the following description and the accompanying drawings. These descriptions of embodiments set forth below for enabling embodiments of the present invention to be practiced are not intended to limit the preferred embodiments, but serve as particular examples thereof. Those skilled in the art will appreciate that they can readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent assemblies do not depart from the spirit and scope of the present invention in its broadest form.

[0017] For the sake of clarity and conciseness, descriptions of well-known functions and structures have been omitted. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, the use of the terms "a," "an," etc., does not denote a limitation of quantity, but rather denotes the presence of at least one of the referenced item.

[0018] The use of terms such as "first" and "second" does not imply a particular order, but rather is included to identify particular elements. Furthermore, the use of terms such as first, second, etc. does not imply an order of importance, but rather the use of terms such as first, second, etc. distinguishes one element from another. It will be further understood that, as used herein, the terms "comprise" and / or "comprising," or "include" and / or "including," specify the presence of stated features, regions, integers, steps, operations, elements, and / or components, but do not exclude the possibility of the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0019] Although some features may be described in connection with individual exemplary embodiments, the aspects need not be limited to that embodiment, as features from one or more exemplary embodiments may be combined with other features from one or more exemplary embodiments.

[0020] In accordance with certain aspects of an embodiment of the present invention, and with particular reference to FIGS. 1 and 2 , an internally illuminated bioreactor (generally designated 100) is provided that incorporates a submerged culture light illumination device 200 that efficiently and effectively manages heat generated by light emitting elements, such as light emitting diodes ("LEDs"), on the submerged culture light and ensures that the heat generated by these light emitting elements does not adversely affect the surrounding algae culture. In one exemplary configuration, the bioreactor 100 includes an outer shell 102 formed from a lightweight material capable of supporting the desired dimensions and volume of the bioreactor 100, such as, but not limited to, polyethylene, HDPE, PTFE, or other plastics, fiberglass, stainless steel, carbon steel, borosilicate glass, ceramic, and similarly constructed materials. In certain exemplary configurations, the material of the outer shell 102 is formed from a food-grade plastic or other material capable of meeting food-grade material approval requirements. In certain exemplary configurations, the shell 102 may optionally be configured with a reflective inner surface that can reflect light emitted from the internal culture light irradiator back onto the algae culture contained within the shell 102. A substantially sealed aquarium lid 104 may be attached to the open top of the shell 102 to provide a sealed internal culture vessel 106 that minimizes evaporation and contamination and preferably provides for tightly controlled culture environments. The lid 104 similarly includes ports or openings that allow various elements of the bioreactor to pass through the culture vessel 106, including a central opening for receiving the submersible culture light irradiator 200, one or more openings for receiving one or more drives for the automatic cleaning system 300 (shown particularly in FIG. 9 and described in more detail below), and preferably one or more additional openings for one or more of nutrient addition, inlet air and CO2 lines, water addition, or aeration. The lower portion of the inner culture vessel 106 may be provided with one or more spargers 105, which may receive air and / or CO 2 from outside the bioreactor 100.The spargers 105 may be arranged in several ways, such as a linear array positioned at various locations beneath the culture vessel 106, or as a ring or other configuration surrounding or attached to the submersible culture illumination device 200, as would be readily apparent to one skilled in the art as best suited to the particular configuration of the bioreactor 100, and in one particular configuration may include an impeller or similar configuration to further assist in moving the sparging gas through the culture vessel 106. A drain (not shown) may also be provided at the base of the shell 102 to allow for sampling and / or harvesting of the culture from the culture vessel 106 and draining of the bioreactor 100. An automatic control system is also preferably provided, which (as described in more detail below) provides complete monitoring and control of the bioreactor 100, preferably remotely.

[0021] In one exemplary embodiment, as shown in FIGS. 3 and 4 (FIG. 3 shows the submersible culture light irradiation device 200 assembled and FIG. 4 shows the device in an exploded view), and in the enlarged perspective cross-sectional view of FIG. 5, the submersible culture light irradiation device 200 includes a preferably circular metallic inner tube 202, which in certain configurations is formed from aluminum (to provide excellent thermal conductivity and a cost-effective, lightweight assembly). The inner tube 202 forms the core of the submersible culture light irradiation device 200, providing structural, strength, and heat dissipation properties, as well as a conduit (including the interior space of the hollow, circular aluminum inner tube 202) that allows forced air to reach the lower portion of the inner tube 202. Attached to the outer surface of the tube 202 are a plurality of metal heat dissipation strips 204, again preferably formed from aluminum, each of which has one or more LED chip assemblies 208 attached to its outer surface. The heat dissipation strips 204 extend upward from the bottom of the inner tube 202 and typically terminate at a point on the inner tube 202 that is below the top surface of the culture in the culture vessel 106. In one exemplary configuration, five heat dissipation strips 204 are attached to the outer surface of the tube 202 in a symmetrical pattern, although other numbers of heat dissipation strips 204 may be provided to suit the particular configuration of a given embodiment. Each heat dissipation strip 204 contacts its outer surface of the tube 202 to ensure effective heat transfer between the inner tube 202 and the heat dissipation strip 204. As a non-limiting example, a portion of the outer surface of the tube 202 may be formed with a flat area to receive one of the heat dissipation strips 204, each having a flat rear surface. Alternatively, the rear surface of each strip 204 may have a shallow channel formed therein along the center of the rear of each strip 204 to similarly increase the surface area of ​​contact between each heat dissipation strip 204 and the inner tube 202. This increased contact surface area between the inner tube 202 and the planar heat dissipation strips 204 allows more heat to be removed more quickly from the LED phosphors located in front of each heat dissipation strip 204, thereby keeping the inner tube 202 and heat dissipation strips 204 comfortably within their normal operating temperature range.5, each heat dissipation strip 204 is preferably positioned relative to the inner tube 202 such that, upon discharge from an opening near the bottom of the submersible light irradiation device 200 (as described in more detail below), forced air travels along at least a portion of the top, sides, and bottom of each heat dissipation strip 204. Those skilled in the art will recognize that, based on the particular implementation of the bioreactor 100, the material composition and thickness can be readily adjusted by one skilled in the art to achieve a particular desired heat transfer therebetween.

[0022] The heat dissipation strip 204 may be attached to the inner tube 202 via fasteners such as screws or bolts, or may be welded or adhesively bonded to the inner tube 202. In one particular configuration, the heat dissipation strip 204 may be bonded to the inner tube 202 with a thermally conductive epoxy or silicone compound. Such compounds are typically synthetic resins reinforced with metal or inorganic filler materials. The use of such optimized thermally conductive materials can increase the utilization efficiency of the submersible culture light and reduce the energy required to keep the culture light operating at a desired temperature. Such epoxy resins and compounds may exhibit certain advantages over screws, bolts, or welds, such as one or more of: (i) providing higher thermal conductivity and improved heat removal; (ii) establishing a larger (and more effective) contact area between the heat dissipation strip 204 and the inner tube 202; (iii) providing improved resistance to shock and vibration; (iv) providing better thermal stability; or (v) providing superior mechanical strength. Such epoxies and compounds allow for spacing between the inner tube 202 and the heat dissipation strip 204, providing additional options beyond screws, bolts, or welding. Varying the spacing can vary the airflow moving through the space between the inner tube 202 and the heat dissipation strip 204.

[0023] As mentioned above, a row of LED chips 208 (or phosphors) is disposed along the length of the heat dissipation strip 204. While the exemplary embodiments described herein utilize LED chips 208, among others, those skilled in the art will recognize that other high-intensity light-emitting elements, both existing and developed in the future, may be employed in place of the LED chips 208 disclosed herein, so long as such light-emitting elements can be linearly arranged on the heat dissipation strip 204, as described herein. In the exemplary configurations described herein, the LED chips 208 are preferably customizable in several ways, including, but not limited to, intensity, color, and temperature, to maximize the growth of specific strains of algae. Preferably, at least one row of LED chips 208 is provided on each heat dissipation strip 204 (although these may optionally be provided in multiple rows and / or columns, with different or equal numbers on each heat dissipation strip 204), such that the LED chips 208 provide a 360° illumination range within the bioreactor 100, with each strip of LED chips 208 exhibiting a diffusion angle of approximately 180°. Preferably, the LED chips 208 may be dimmed via an automatic controller to optimize the light intensity of the LED chips 208 relative to the current density of the culture in the bioreactor 100, as detected using an in-culture sensor, as described in more detail below.

[0024] The submersible culture light irradiation device 200 further includes a transparent outer tube 210 ( FIG. 1 ) that houses the inner tube 202 and the heat dissipation strip 204. As best shown in FIGS. 6 and 7 , metal disks 206(a) and 206(b) are preferably attached to the upper and lower ends of the inner tube 202, respectively. These metal disks 206(a) and 206(b) are preferably made of the same metal, such as aluminum, as the inner tube 202 to further promote heat dissipation. The disks 206(a) and 206(b) also function to center and optimally position the inner tube 202 and the heat dissipation strip 204 within the transparent outer tube 210. More specifically, as shown in FIG. 1 , the inner diameter of the transparent outer tube 210 is preferably slightly larger than the diameter of the disks 206 at the top and bottom of the inner tube 202 to ensure stability of the submersible culture light irradiation device 200 while housed within the outer tube 210 during use. Additionally, the disks 206(a) and 206(b) are preferably sized relative to the inner tube 202 to reduce the distance between the inner tube 202 and the heat dissipation strip 204 attached to the inner tube 202 and the interior of the transparent outer tube 210. In one exemplary configuration, the LEDs on the heat dissipation strip 204 may be positioned between 1.25 cm and 5 cm from the interior of the transparent outer tube 210 where the individual submersible culture light irradiation devices 200 are located, although other distances may be employed depending on the overall size of the bioreactor 100.

[0025] The upper disk 206(a) preferably includes a centrally drilled through-hole into which a barb or other inlet 207 is attached for attachment to a source of compressed air, which is then forced through the upper disk 206(a) and into the top of the inner tube 202. Additionally, the upper disk 206(a) preferably includes one or more openings 216, such as openings along the outer edge of the upper disk 206(a), configured to allow heated air within the transparent tube 210 to escape from the underwater light irradiation device 200. The openings 216 in the upper disk 206(a) are configured and positioned to maximize the flow of air vented from the transparent tube 210. The openings 216 are preferably cut into the upper disk 206(a) and extend inward from the edge of the upper disk 206(a). Optionally, in certain configurations, the lower disk 206(b) may be encased in or within a lower outer layer of cushioning material, which in one exemplary configuration comprises neoprene or rubber, to provide a cushion or shock absorber between the submerged culture light irradiation device 200 and the lower interior of the outer shell 102 of the bioreactor 100, thereby keeping the aluminum of the culture light irradiation device 200 spaced apart from and out of direct contact with the outer shell 102.

[0026] The transparent outer sleeve 210 of the culture light irradiation device 200 is preferably sealed at its bottom end and open at its top end, which extends beyond the top lid 104 of the bioreactor 100 to provide access to the LEDs, heat dissipation strip 402, and other elements of the culture light irradiation device 200 when maintenance is required. The transparent outer sleeve 210 is preferably secured to the lid 104 of the bioreactor 100 by a connection scheme that allows it to be removed for maintenance. While many such connection schemes can be adopted and configured by those skilled in the art for a particular configuration, one exemplary connection scheme, by way of non-limiting example and as shown in FIG. 8 , may include a flange collar ring 108 and one or more cotter pins 110 aligned vertically through the flange collar ring 108, which can hold the transparent outer sleeve 210 securely in place against the buoyancy of the submersible culture light irradiation device 200 and against turbulent flow within the bioreactor 100. In one particular exemplary embodiment, the flange collar ring 108 extends beyond the lid 104 of the bioreactor 100 by a distance determined by the exterior dimensions of the bioreactor 100. For example, a bioreactor 100 having a height of 10 feet will require a smaller flange collar ring 108 than a bioreactor 100 having a height of 25 feet or more. The dimensions of the flange collar ring 108 are relative to the dimensions of the bioreactor, and therefore relative to the dimensions of the submersible culture light irradiation device 200. Cotter pins 110 can pass through the entire flange collar ring 108 and through the transparent outer sleeve 210 to further secure the submersible culture light irradiation device 200 in place within the bioreactor 100.

[0027] The transparent outer cylinder 210 is preferably made of glass, acrylic, or a similarly constructed material. One or more transparent outer cylinders 210 with sealed submersible light irradiation devices 200 may optionally be provided within a single bioreactor 100, with each outer cylinder 210 vertically positioned within the bioreactor 100 so that it extends close to the floor of the bioreactor and at a distance from the other transparent outer cylinders 210, so that the entire algae culture receives approximately the same amount of irradiation from the submersible light irradiation devices 200. Thus, a single bioreactor 100 may include multiple submersible culture light irradiation devices 200 depending on its size, with the number of such culture light irradiation devices 200 determined by the ease of penetration of the submersible culture light irradiation devices 200 into the algae culture, preferably to a depth of at least 15 cm measured from the transparent outer cylinder 210.

[0028] 1-9, the bioreactor 100 includes an automatic cleaning system 300 configured to maintain the exterior surface of the transparent outer casing 210 free of debris and algae growth, thereby enabling the bioreactor 100 to operate as continuously as possible. The automatic cleaning system 300 also automatically moves up and down along the transparent outer casing 210, scraping the outer casing 210 to prevent the algae culture from adhering to and clumping on the transparent outer casing 210. In one exemplary configuration, the automatic cleaning system 300 includes a motor 302, such as an electric motor, that drives a linear actuator 304 that is connected to a cleaning device, such as a wash ring 306. The motor 302 and linear actuator 304 may be attached to the lid 104 of the bioreactor 100 such that the linear actuator 304 extends through the lid 104 and along the entire length of the transparent outer casing 210. Linear actuator 304 (which may include, by way of non-limiting example, a worm gear, a belt-driven linear actuator, or other linear actuator assembly readily apparent to one of ordinary skill in the art) is attached at its upper end to motor 302 and at its lower end to a support bracket (not shown) mounted inside bioreactor 100, which maintains linear actuator 304, and thus attached washing ring 306, in close proximity to transparent outer casing 210. Washing ring 306 may be formed, by way of non-limiting example, from PVC or a similar material and may include an internal brushing surface, such as a section of hook-and-loop fastening material, attached to the internal surface of washing ring 306 that contacts and preferably surrounds the external surface of transparent outer casing 210. As motor 302 powers washing ring 306 as it moves up and down the length of transparent outer casing 210, the internal brushing surface of washing ring 306 moves along the external surface of transparent outer casing 210, thereby removing any accumulated algae or other material from transparent outer casing 210. The automatic cleaning system 300 may be driven by a timer that allows cleaning to be scheduled at desired intervals depending on the culture regime and other factors that affect the susceptibility of the algae culture to adhere to the cylinder surface.Although not separately shown in the figures, one skilled in the art will readily recognize that the automatic cleaning system 300 may include other elements, such as conventional linear drive guide bars and limit switches, that reverse the direction of movement of the cleaning ring 306 (controlled by the motor 302) when the cleaning ring 306 reaches designated points near the top and bottom of the sheath 210, and that these other elements could be readily configured by one skilled in the art for a given exemplary configuration. Similarly, one skilled in the art will recognize that other actuators for the cleaning ring 306 may be provided to move the cleaning ring 306 back and forth along the length of the sheath 210 of the light irradiation device 200 without departing from the spirit and scope of the present invention. Furthermore, cleaners other than a complete ring surrounding the sheath 210 may similarly be employed without departing from the spirit and scope of the present invention.

[0029] As described above, proper heat management in the submersible culture light irradiation device 200 is essential to ensure heat management of the algae culture, but it has significantly hindered effective algae cultivation in industrial-scale bioreactors. Therefore, a sustainable and economically viable cooling process for the submersible culture light irradiation device 200 is crucial to the success of the entire bioreactor system, especially on an industrial scale. If the heat transferred by the LEDs on the heat dissipation strip 204 is not properly managed and dissipated, it can affect the surrounding algae culture and potentially render the culture light inoperable or significantly shorten its lifespan. Proper heat management and dissipation, i.e., heat must be rapidly removed from the bioreactor in order to successfully operate an industrial-scale production system.

[0030] To address these thermal management challenges, the bioreactor 100 includes a thermal management system that provides cooling for the submersible light irradiation device 200. Using such a thermal management system, the operating environment of the bioreactor 100 can be optimized by regulating airflow to accelerate heat dissipation and by creating a controlled pressure differential between the inside and outside of the inner cylinder 202. With particular reference to FIGS. 1, 6, and 7, the upper disk 206(a) of the inner cylinder 202 includes an inlet 207, preferably located at the center of the upper disk 206(a), providing a cooling fluid inlet to the interior of the inner cylinder 202. As used herein, the term "fluid" encompasses flowable media and, therefore, includes gas, more specifically air, as the flowing "fluid" cooling medium used in accordance with certain aspects of the present invention. In a particularly preferred embodiment, the inlet 207 is in fluid communication with a source of compressed air that can be pumped into the upper portion of the inner cylinder 202. Exhaust ports 214 may be provided along the outer periphery of the inner barrel 202 adjacent its lower portion, specifically immediately above the lower circular disk 206(b). In this configuration, compressed air is forced through the inlet 207 and cools the interior of the inner barrel 202 as it travels downward through the vertical length of the inner barrel 202. The air exits the inner barrel 202 through the outlet 214 at the bottom of the inner barrel 202 and then travels upward through the space between the interior of the transparent outer barrel 210 and the outer surface of the inner barrel 202. As it travels through this space, the cooling air flows upward along the outer surface of the inner barrel 202 and, as best shown in FIGS. 1 and 5, over and under at least the sides of the heat dissipation strips 204, thereby cooling the LED chips 208 before being exhausted through the openings 216 in the upper disk 206(a). Those skilled in the art will recognize that the opening 216 in the top disk 206(a) may take a variety of forms, so long as it allows exhaust cooling air to escape from the light irradiation device 200. In certain configurations, the transparent outer barrel 210 may optionally include a removable top lid 211 that also includes an air exhaust port 211(a) at its upper end.

[0031] The flow rate of the compressed or forced air pumped into the underwater lighting device 200 varies depending on the lighting requirements of the user, the length and quantity of light emitting elements provided, and the desired temperature of the algae culture. As described in more detail below, the flow rate of the compressed air may be adjusted to maintain the desired temperature of the LED chips 208, and to maintain the desired temperature within the transparent outer casing 210 and the algae culture itself.

[0032] To maintain such a desired temperature, the airflow velocity or rate (cfm or m) is increased as the light intensity of the submersible culture light irradiation device 200 increases. 3 The light intensity (measured in kJ / s) may be increased as the density of the algae culture increases to maintain the most effective cultivation environment within the cultivation vessel 106. This increase in light intensity also increases the temperature of the submersible cultivation light irradiation device 200 (measured at the surface of the LED light strip and in the air / space between the outer surface of the inner tube 202 and the outer tube 210 that houses it). Therefore, as the light intensity increases, the airflow rate similarly increases to re-equilibrate the temperature around the submersible cultivation light irradiation device 200. In certain configurations, the air may optionally be cooled using standard cooling techniques to further assist in removing heat from the light irradiation device 200. As described in more detail below, such adjustments may be performed using sensors and automatic controllers.

[0033] Although the LED chips 208 operate very efficiently, they still generate heat and transfer it via thermal radiation through their substrate and open space. Therefore, the bioreactor 100 configuration described herein uses airflow to dissipate heat within the inner tube 202 and minimizes radiative heat transfer, i.e., thermal radiation, within the transparent outer tube 210. By adjusting the airflow in this manner, any heat generated by the LED chips 208 can be properly managed and dissipated to the extent that the heat does not adversely affect the desired temperature of the surrounding culture.

[0034] Furthermore, the thermal management system configured as described herein generates a pressure difference within the submersible culture light irradiation device 200, which assists in highly efficient air movement within the submersible culture light irradiation device 200 without the need for a fan or similar device. Air, more preferably compressed air, is forced into the interior of the inner tube 202, moves downward through the inner tube 202, and is then forced out of the inner tube 202 through the outlet 214 at the bottom of the inner tube 202. As the volume and pressure increase within the closed space inside the inner tube 202, the internal air heated by the LED chips 208 is forced out. Pressure and other forces then force the heated air out of the transparent outer barrel 210, such as through air outlet 211(a) at the top of the transparent barrel 210 (or simply through the open top end of the transparent barrel 210), and upward through the transparent outer barrel 210 (i.e., movement between the interior of the transparent barrel 210 and the inner barrel 202 / heat dissipation strip 204 / light emitting element 208). The pressure may be monitored and controlled via an automatic controller, as described in more detail below.

[0035] Additionally, airflow turbulence within the inner tube 202 is minimized by providing a relatively smooth surface within the inner tube 202, preferably with a constant cross-sectional area throughout the entire length of the tube. As a result, air moves rapidly through the inner tube 202 from the upper return inlet toward and through the outlet 214 located at the bottom of the inner tube 202. After exiting the inner tube 202 through the lower outlet 214, the heated air is forced by thermal buoyancy toward the top of the transparent outer tube 210, passing over, under, and around the heat dissipation strips 204 attached to the outer surface of the inner tube 202. Thus, the presence of the heat dissipation strips 204 increases flow path turbulence on the outer surface of the inner tube 202. Alternatively, the cross-sectional area of ​​the inner tube 202 may optionally decrease as the airflow moves downward through the inner tube 202. As the cross-sectional area of ​​the inner cylinder 202 decreases, the fluid flow accelerates, allowing for more rapid evacuation and cooling of the inner cylinder 202 and the entire submersible culture light irradiation device 200. This configuration may be particularly preferable in configurations of bioreactors 100 with longer overall lengths, such as those employing submersible culture light irradiation devices 200 with lengths of 6 meters or more, which may be used in larger bioreactors.

[0036] While the foregoing description specifically includes configurations in which compressed air is delivered to the interior of the inner barrel 202, in other exemplary configurations of the bioreactor 100 that are relatively small (e.g., 1000-1500 liters total volume, by way of example), fewer light emitting elements 208 may generate less heat and, therefore, require less cooling. In such configurations, as described above, a fan or similarly configured forced air source may be provided to force air into the interior of the inner barrel 202 and generate the cooling airflow described above. Also, in such smaller configurations, the top disk 206(a) may optionally be omitted entirely.

[0037] The compressed air and / or forced air supplied to the submersible culture light irradiation device 200 is preferably dry air with minimal humidity, since it is used to cool a series of electronic components within the submersible culture light irradiation device 200. The air supplied to the submersible culture light irradiation device 200 is preferably dried at its supply source, but alternatively, an in-line filter and drain can be used to dry the air before it is sent to the submersible culture light irradiation device 200.

[0038] According to a further aspect of an exemplary embodiment of the present invention, after a desired amount of algae has been produced in the bioreactor 100, the algae can be drained and then harvested from the bottom of the bioreactor 100. This allows gravity to perform most of the work of delivering the algae culture to the drain of the bioreactor 100. If the bioreactor 100 has a generally conical bottom, the drain is preferably located at the bottom of the cone. If the bioreactor 100 has a flat exterior bottom, the drain is preferably located at the bottom of the side of the outer shell 102 of the bioreactor 100, or a sloped, raised bottom or the like may be provided inside the bioreactor 100 to allow the settled algae to naturally migrate toward the drain. In either case, both of these drain locations provide a solution for locating the drain in the lowest energy location within the bioreactor 100. A pump is not required to drain a bioreactor 100 configured as described above, although a pump can optionally be used to speed up the drainage process.

[0039] A controller may be provided to automatically regulate the operation of the bioreactor 100, for example, via an interface incorporating off-the-shelf sensors and a software operating system. More specifically, as described in more detail below, the culture environment within the bioreactor 100 may be automatically regulated by monitoring and maintaining tight control over certain key variables known to affect algae production, including culture temperature, light intensity, pH, flow rate, nutrient levels, and air / gas flow. Data tracked by individual sensors within the bioreactor 100 may be collected and sent to a central dashboard for analysis, and may be integrated with data from other bioreactor sensors to ensure preprogrammed settings are maintained throughout the bioreactor. All such data is preferably displayed remotely, such as via an internet connection. Additionally, controls may be enabled or disabled remotely. Finally, the bioreactor 100 may be equipped with alarms that can be heard and / or intercepted remotely, for example, via a cell phone, tablet, or computer.

[0040] The controller may receive data from a temperature sensor positioned to monitor the temperature of the LED chip 208. The LED chip temperature sensor may be mounted adjacent to the LED chip 208 on an LED substrate, which is attached to the planar heat dissipation strip 204, to provide the controller with the real-time operating temperature of the LED chip 208. The controller may also receive data from a temperature sensor positioned to monitor the temperature of the algae culture (in the water). The temperature of the algae culture may be monitored with a temperature sensor to ensure that the culture maintains a desired temperature, or remains within a certain small temperature range. Each strain of algae grows most effectively at a certain optimum temperature or within a certain optimum temperature range, and the controller may be configured to adjust other elements of the bioreactor (as described further below) to ensure that such optimum temperature or temperature range is maintained. A fail-safe switch in communication with the LED chip temperature sensor and, optionally, the algae culture temperature sensor may be provided to ensure the submersible culture light irradiation device 200 turns off if the LED substrate temperature exceeds, by way of non-limiting example, 75°C, further protecting the LED chip 208 and associated electronics in the event of a failure in the airflow supply. The automated system may also be configured to send an alarm to a pre-set phone, tablet, computer, or other remote device to alert a technician or other individual that the LED substrate temperature has exceeded 75°C, and may also trigger an alarm if the temperature reaches a pre-set value below 75°C. Additionally, one or more temperature sensors may be provided in the air / space between the LED chip and the interior of the transparent outer casing 210 to ensure that the air in direct contact with the transparent outer casing 210 (which air is in turn in direct contact with the algae culture) is maintained within a desired temperature range.

[0041] Preferably, an automated system is configured to control three key elements in the algae culture environment that affect culture temperature: the temperature of the light irradiation device, the airflow rate to the sparger, and the ambient air temperature. More specifically, with respect to the temperature of the light irradiation device, the controller may vary the airflow rate to the device to cool or heat the device 200, thereby cooling or heating the algae culture to a specific desired temperature. Similarly, with respect to the airflow to the sparger at the bottom of the culture vessel 106, the controller may directly monitor the temperature of the algae culture and automatically adjust the airflow to the sparger, thus delivering gas or air directly to the algae culture as a secondary means of influencing culture temperature. Furthermore, with respect to the ambient air temperature, the controller may adjust the ambient room temperature through a connection to a room heating or cooling system as yet another means of cooling or heating the algae culture in the bioreactor 100.

[0042] The controller may further monitor one or more humidity sensors positioned to detect the amount of moisture in the air supplied to the submersible light irradiation device 200. If the detected amount of moisture exceeds a predetermined level, the controller may automatically shut down the submersible culture light irradiation device 200 and may send an alarm to the above-mentioned pre-set devices to alert them to the increasing moisture content and allow them to investigate.

[0043] The controller may further monitor the density of the culture within the bioreactor 100 via submersible light intensity sensors located throughout the bioreactor. The controller can monitor the density and light intensity readings and control the light intensity of the submersible culture light irradiator 200 to generate an optimal level of light intensity through the culture depending on the desired settings.

[0044] Additionally, the controller can monitor the pH of the algae culture in the bioreactor 100 via a submersible sensor and control the pH by injecting CO2 into the culture until the appropriate pH value is reached and maintained. In an exemplary configuration, the controller can be configured to maintain any desired pH value, such as a pH value in the range of 9-10 to promote high growth, or possibly a pH value in the range of 5-7 to reduce greenhouse gases on an industrial scale. The controller can further send an alarm to the aforementioned pre-configured device to alert it if the pH exceeds or falls below a predetermined threshold level.

[0045] Furthermore, the controller may monitor the conductivity and oxidation-reduction potential ("ORP") of the culture and may control and / or add nutrients in appropriate amounts, either by slow drip or batch delivery. The controller may further send alarms to the above-mentioned preset devices to alert them if there is a malfunction in the nutrient delivery system.

[0046] Furthermore, the controller can direct the air regulator to inject more air and / or CO2 finely into the culture at the bottom of the bioreactor through the sparger to control the movement of the algae culture within the cultivation vessel 106. This continuous movement of the culture within the cultivation vessel 106 can be important to the growth of the entire culture because it ensures equal exposure of the entire algae culture to the light emitted by the submersible cultivation light irradiator 200 and also reduces algae buildup on the transparent outer casing 210 of the submersible cultivation light irradiator 200 and on the exterior walls of the cultivation vessel 106, which could reduce the effectiveness of the device.

[0047] The controller may further communicate with an algae culture density sensor to automatically drive a harvesting mechanism in the drain of the bioreactor 100. The density sensor reading may indicate that maximum algae growth has been reached, and before the growth rate of the mature culture has stabilized and plateaued, the drain of the bioreactor 100 may be activated and opened to release a predetermined amount of culture from the culture vessel 106. A pipe attached to the drain preferably delivers the harvested culture to a harvesting point, where it may be processed. Once a certain amount of culture has been released from the bioreactor, the controller may add an equal amount of fresh, treated water (up to the required limit) to the bioreactor 100 from the top. Optionally, the controller may manage either batch harvesting at a specified time, or reaching a planned algae production volume, or continuing harvesting, or both. Similarly, the controller may add the appropriate amount of nutrients depending on the amount of water added and the time elapsed since the last nutrient input. The controller may also send an alarm to the above-mentioned preset devices to alert them if a malfunction occurs during the harvesting process.

[0048] Finally, the controller can drive the automatic cleaning system 300 to move the cleaning ring 306 up and down within the transparent outer tube 210. The automatic cleaning system 300 can be driven to do so periodically, or the automatic cleaning system 300 can be automatically activated when the light intensity sensor reading falls below a predetermined threshold level. The settings for the automatic cleaning system 300 can vary depending on the algae strain being cultivated within the bioreactor 100. Some strains may require frequent cleaning, while others may require little or no cleaning at all. The role of the automatic cleaning system 300 described herein is to keep the bioreactor running continuously for as long as possible. The controller can also send alarms to the pre-configured devices mentioned above to alert them if a malfunction occurs during the cleaning process.

[0049] When using a bioreactor configured as described above for algae production, it may be preferable to prepare the water for culturing the algae in the culture tank 106. Generally, there are various methods for appropriately preparing the water used to start and maintain a bioreactor. Some producers may treat the water with bleach or ozone or another cleaning agent before planting. Using reverse osmosis water is another method that may be employed, and does not pose the risk of killing the algae, as bleach does if not properly diluted. The water preparation method selected by a producer is likely to have a great deal to do with what is most convenient and cost-effective for their particular location. However, a bioreactor configured according to the foregoing disclosure can be installed in any location and therefore does not impose a particular water preparation method on the user of the bioreactor. Rather, a bioreactor configured according to the foregoing disclosure can employ any water preparation method, and all prepared water is optionally injected into the bioreactor 100 through a dedicated port in the lid 104 of the bioreactor 100.

[0050] Bioreactors configured in accordance with the foregoing disclosure may offer several improvements over prior art systems and methods for producing algae. For example, bioreactors configured as described above can provide complete and uniform light penetration throughout large-diameter bioreactors and tanks (e.g., those having diameters greater than one meter). The ability to properly illuminate tanks or bioreactors internally allows for the use of larger tanks than previously considered, such as in systems that may utilize sunlight or culture lights located outside the bioreactor. Furthermore, the use of large, internally illuminated tanks or bioreactors can optimize the footprint of indoor or outdoor cultivation facilities, particularly when considering both cubic feet and square feet, and can help minimize the footprint relative to production capacity. These factors allow producers to truly maximize the productivity of the available footprint, thereby providing a key efficiency factor that may be required for cost-effective scaling up indoor cultivation at industrial levels. Thus, a bioreactor constructed according to the foregoing disclosure may be scaled to any dimension and may be installed and operated virtually anywhere in any external environment and may fit into any available footprint.

[0051] Furthermore, a bioreactor configured as described above can provide an appropriate amount of light to a large-scale culture, ensuring that the culture does not overheat due to the generated heat energy. More specifically, the thermal management system allows the submersible light-irradiation device 200 to fully penetrate the liquid culture without transferring heat to the culture, and maintains the submersible light-irradiation device at an optimal operating temperature while maintaining durability and reducing the likelihood of overheating. Furthermore, a bioreactor configured as described above can substantially prevent the accumulation of algal detritus on the transparent outer casing 210 surrounding the submersible light-irradiation device 200, which would otherwise tend to reduce light intensity, and can avoid the need to periodically interrupt algal production to clean the interior of the bioreactor.

[0052] Similarly, the bioreactor configured as described above can provide an optimal culture environment for algae by automatically controlling and / or adjusting five major factors that affect algae cultivation: light intensity / spectrum, pH, temperature, nutrients, and air / culture medium flow.

[0053] While preferred embodiments and certain modifications of the concepts underlying the present invention have now been fully described, various other embodiments and certain variations and modifications of the embodiments shown and described herein will readily occur to those skilled in the art who are familiar with the concepts underlying the present invention. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein.

Claims

1. The outer shell and A light irradiation device within the outer shell, A light irradiation device outer cylinder configured to pass light from the light irradiation device into a culture tank in the outer shell; a light irradiation device inner cylinder housed in the light irradiation device outer cylinder, the light irradiation device inner cylinder having a first flow path extending in an internal space from an upper portion to a lower portion thereof, and at least one outlet from the first flow path adjacent to the lower portion thereof; a light irradiation device including a plurality of light emitting elements arranged along the outer periphery of the inner cylinder of the light irradiation device; a forced air source in fluid communication with the first flow path and forcing air into the first flow path; a second flow path is defined between the plurality of light-emitting elements and the inside of the light irradiation device outer cylinder, and the second flow path receives the heated air that has passed through the first flow path and is discharged from the at least one outlet, and delivers the heated air from the at least one outlet to an upper portion of the light irradiation device by buoyancy of the heated air; Internally irradiated bioreactor.

2. 2. The internal irradiation bioreactor of claim 1, wherein the light irradiation device is further configured to deliver the warmed air from the at least one outlet to an upper portion of the light irradiation device without the use of a mechanical air conditioning device.

3. 10. The internal irradiation bioreactor of claim 1, further comprising a movable cleaning device in contact with an exterior surface of the light irradiation device sheath, and a motor in driving engagement with the cleaning device and configured to move the cleaning device along a vertical length of the light irradiation device sheath.

4. 4. The internal irradiated bioreactor of claim 3, wherein the cleaning device further comprises a ring movably mounted on a linear drive, the linear drive engaging the motor.

5. 5. The internal irradiation bioreactor of claim 4, wherein the ring further comprises a brushing surface on an inner circumference of the ring, the brushing surface contacting an outer surface of the light irradiation device outer cylinder.

6. 2. The internal irradiation type bioreactor according to claim 1, wherein the light irradiation device further includes a plurality of heat dissipation strips attached to the outer surface of the light irradiation device inner tube, and the light emitting element is attached to the outer surface of each of the heat dissipation strips.

7. 7. The internal irradiation type bioreactor of claim 6, wherein each of the heat dissipation strips further includes a flat strip, the central portion of the back surface of each of the flat strips being attached to the outer surface of the light irradiation device inner tube, and the edge portion of each of the back surfaces of each of the flat strips being positioned away from the outer surface of the light irradiation device inner tube.

8. 10. The internal irradiated bioreactor of claim 1, wherein the forced air source further comprises a compressed air source that forcibly delivers air to the first flow path without the use of a mechanical air conditioning device.

9. 9. The internal irradiation bioreactor of claim 8, wherein the light irradiation device inner tube has an upper disk that sealingly engages an upper end of the light irradiation device inner tube and a compressed air inlet that extends through the upper disk.

10. 10. The internal irradiation type bioreactor according to claim 9, wherein the diameter of the upper disk is larger than the diameter of the inner cylinder of the light irradiation device.

11. 11. The internally irradiated bioreactor of claim 10, wherein the top disk has at least one heated air outlet extending therethrough and in fluid communication with the second flow path and an air outlet of the light irradiator sheath.

12. 10. The internally irradiated bioreactor of claim 1, wherein the forced air source further comprises a fan configured to direct air through the first flow path.

13. an outer shell defining an algae culture tank therein; a light irradiation device in the algae culture tank, the light irradiation device further comprising: a light irradiation device outer cylinder configured to transmit light; a light irradiation device inner cylinder disposed inside the light irradiation device outer cylinder; a plurality of light emitting elements disposed along the outer periphery of the light irradiation device inner cylinder; a first air flow path extending into an internal space from an upper portion of the light irradiation device inner cylinder to a lower portion of the light irradiation device inner cylinder; at least one lower outlet from the first air flow path adjacent to the lower portion of the light irradiation device inner cylinder; and a second air flow path extending from the lower portion of the light irradiation device to the upper portion of the light irradiation device between the plurality of light emitting elements and the inside of the light irradiation device outer cylinder; a forced air source in fluid communication with the first flow path and forcing air into the first flow path; the light irradiation device is configured to deliver air from the first flow path through the second air flow path via the at least one lower exhaust outlet and from the light irradiation device to the exhaust outlet by buoyancy of the air in the second air flow path without the use of a mechanical air conditioning device. Internally irradiated bioreactor.

14. 14. The internal irradiation bioreactor of claim 13, further comprising a movable cleaning device in contact with an exterior surface of the light irradiation device, and a motor in driving engagement with the cleaning device and configured to move the cleaning device along a vertical length of the light irradiation device.

15. 14. The internally irradiated bioreactor of claim 13, wherein the light irradiation device further includes a plurality of heat dissipation strips attached to the outer surface of the hollow light irradiation device inner cylinder, and the light-emitting element is attached to the outer surface of each of the heat dissipation strips.

16. 16. The internal irradiation bioreactor of claim 15, wherein each of the heat dissipation strips further includes a flat strip, the central portion of the back surface of each of the flat strips is attached to the outer surface of the light irradiation device inner tube, and the edge portion of the back surface of each of the flat strips is positioned away from the outer surface of the light irradiation device inner tube.

17. 14. The internal irradiated bioreactor of claim 13, wherein the forced air source further comprises a compressed air source that forcibly delivers air to the first flow path.

18. 18. The internal irradiation bioreactor of claim 17, wherein the light irradiation device further comprises a hollow light irradiation device inner barrel having an upper disk sealingly engaging an upper end of the light irradiation device inner barrel and a compressed air inlet extending through the upper disk.

19. 20. The internally irradiated bioreactor of claim 18, wherein the top disk has at least one heated air outlet extending therethrough and in fluid communication with the second flow path and an air outlet of the light irradiation device.

20. 14. The internally irradiated bioreactor of claim 13, wherein the forced air source further comprises a fan configured to direct air through the first flow path.

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