Abstract: A microwave refining and melting furnace for the treatment of dissolved or solid products includes a first waveguide traversed by a microwave beam generated by a generator coupled to a first end of the first waveguide. The first waveguide is provided with a material supply orifice located at an upper part thereof close to a first end of the first waveguide. The first waveguide has at a lower part thereof, close to a second end, an overflow lock of variable height making it possible to define a retention volume for the materials, which have been progressively melted by a continuous flow along the lower wall of the first waveguide, from the reception point thereof in the first guide. A second waveguide is connected to the first waveguide for refining the materials.

Abstract: Apparatus for the intensive, controlled production of microorganisms by photosynthesis.This apparatus comprises at least one photobioreactor (6) to be placed on an expanse of water (8), which has first group of flexible tubes (38), which are transparent to light and in which circulates the culture medium and a second group of inflatable tubes (62), disposed and maintained beneath the first group by means of detachable Y-shaped interpolated members (70), which are regularly spaced. At least one two-column carbonator (12) connected to the photobioreactor intake (43) for charging the liquid medium with the CO.sub.2 necessary for photosynthesis is provided. Two degassing means (36) connected to the two ends of the photobioreactor are provided for eliminating the oxygen produced by the microorganisms from the liquid medium. There is at least one expansion tank (2) connected to the photobioreactor (6) for reducing possible volume variations in the photobioreactor (6).