Aerobic-cultivation tank

An aerobic-cultivation tank of vertical type comprising:

• a closed outer tank structure of cylindrical shape;
• a cylindrical, open ended inner wall secured concentrically to the inner wall surface of said tank structure, the ends of said inner wall terminating short of the ends of said tank structure;
• an internal cooling jacket defined concentrically between the inner wall surface of said tank structure and the outer wall surface of said cylindrical inner wall and having a cylindrical closed space therebetween for accommodating a coolant;
• a plurality of fluid downcast pipes passed vertically through said space and being open at upper and lower ends above and below, respectively, said space and opening into upper and lower interior parts of the tank structure;
• means for passing the coolant through said space;
• and
• means for supplying fluid media into the tank structure and into said cylindrical inner wall;
• whereby when the fluid media are supplied into said inner wall to a level above the upper end thereof, the fluid media overflow said inner wall and descend through said pipes, while being cooled, into a lower interior part of the tank, while a portion of said fluid media in contact with the inner surface of the cooling jacket is also cooled and descends, the fluid media body as a whole thereby undergoing a natural circulatory flow due to convection.