Abstract: A thermally insulated enclosure (1) containing a bath (20) of liquid nitrogen. The enclosure contains a case (3) of flat shape provided with a thermal insulation (4) whose performance is lower than that (2) of the enclosure (1) and comprising, on one hand, supports (17) for supporting straws in a horizontal plane, and, on the other hand, a heater (8) for heating the lower wall (7) and/or the cover (6) of the case. Application in the freezing of animal or human embryos.

Abstract: The invention relates to the freezing of biological products contained in straws and more particularly to the initiation of the crystallization phase. A series of straws is disposed in such manner that the straws are arranged in parallel side-by-side relation and a crystallization bar (10) is mounted by springs (20) on two arms (11 and 12) connected to a rotary shaft (13). The arms shift the bar between a waiting position in a receiver-cradle (16) which is deeply cooled by a pipe (17-18) and an operative position in which is bears against the straws. Application in the freezing of blood cells, human and animal sperm, fragments of biological tissues and embryos, etc.

Abstract: A freezing device for biological products comprises an impeller arranged at the top of a sleeve located above a basin of liquid nitrogen. The impeller causes a rising flow of nitrogen vapors within the sleeve and a descending flow outside it, the impeller and sleeve being arranged within a casing. When cooling is completed, the sleeve is lowered into the basin of liquid nitrogen. The invention is applied to the freezing of biological products stored in tubes, ampoules, phials, or straws arranged at the base of the sleeve.

Abstract: The present invention relates to a method of and an installation for the treatment of a material oxidizable by a biochemical process, in which at least one oxygenation process is applied to a mixture comprising water, the oxidizable material and a biomass, this oxygenation process comprising at least the three following operations:(1) In an oxygenation zone substantially isolated from the ambient air, establishing a biochemical oxidation system comprising firstly a liquid mass of the mixture to be treated, limited by the lower portion of the oxygenation zone, and secondly a gaseous atmosphere comprising oxygen, surmounting the liquid mass and limited by the upper portion of the oxygenation zone;(2) Circulating in the oxygenation zone by means of a mechanical oxygenation device, one of the constituents of the biochemical oxidation system, namely the portion of the liquid mass and the portion of the gaseous atmosphere, each limited by the portion of the oxygenation zone, in contact with each other;(3) Supplying