PCT application of Nexgen Algae, titled PHOTOBIOREACTOR SYSTEM AND METHOD
Reference D2, JP 2009 195163 to CCS Inc., disclosed photobioreactors connected in series, situated vertically one above the other.
Reference D1, JP 2012 191894 to Ihi Corp., was also cited.
In terms of aperture size for aeration, the specification noted:
 In some embodiments, the plurality of aeration apertures are, independently, each of a diameter in the range of about 0.005 centimeters to about 0.1 centimeters, and preferably about 0.01 centimeters to about 0.05 centimeters, e.g., when used for an algal density of about 0.5% by dry weight. In turn, the end-to-end spacing between adjacent aeration apertures is independently, and preferably, between about 0.01 centimeters to about 1 centimeter, and more preferably between about 0.05 centimeters to about 0.1 centimeter. For instance, a standard photobioreactor of the type described herein (e.g., on the order of 0.5 meters to about 10 meters in overall length, or more preferably on the order of about 1 meter to about 2 meters in length) can have between about 100 and about 1000, more preferably between about 200 and about 800, and even more preferably between about 300 and about 600 aeration apertures per photobioreactor. The apertures can be of any suitable combination of numbers, diameters, spacing and orientation.
Separately, TRANS ALGAE CORPORATION reported in PCT/US2013/050031 :
In the present invention, the material of a microalgal culturing tank (1) is constituted of polyethylene, endowed with flexibility, and formed so as to be substantially a truncated cone. This substantially truncated-cone comprises a disk-shaped bottom surface section (2) and a side surface section (3), the side surface section (3) being configured with a substantially parallel-surface left surface section (6), right surface section (5), front partial cylinder section (8), and rear partial cylinder section (9). To transport a large number of tanks (1) prior to construction, the tanks can be overlapped due to the tanks being a substantially truncated-cone shape, and as a result, the cargo volume can be greatly reduced while a large number of tanks can be shipped at the same time. Upon erection at a microalgal culturing site, a pair of tanks (70) can maintain an upright position which is stable with respect to wind and vibration by bringing the adjacent tanks into surface-contact with each other with the left surface section (6) and the right surface section (5) of the tanks being abutted together. After the tanks (1) have been filled with microalgae and water and installed, because the tank material is polyethylene, solar light and heat rays thereof penetrate into the interior of the tanks, thereby making it possible to accelerate growth of the microalgae.