Abstract: A carbon dioxide snow nozzle for in particular rendering a molten metal inert. The nozzle comprises a supply pipe supplying liquid carbon dioxide under pressure for connection to a source of liquid carbon dioxide under pressure, a T-shaped element having one end connected to the pipe and the other two ends connected to liquid carbon dioxide conveying line which each have and to a controlled valve the outlets of the valves being interconnected by a V-shaped connecting element which opens onto a pipe for discharging the snow.

Abstract: The installation comprises three units separated from one another: a grinding mill (1) fed with pieces of dry ice, a metering device (3) having an extracting spring-screw (13), and a propelling device (5) mounted in a vehicle gas conduit (4). The assembly is maintained under an atmosphere of CO.sub.2 by a cover (6). Application in the cleaning of surfaces in the nuclear industry.

Abstract: The process valorizes food by-products by a reverse osmosis. The pH is temporarily lowered by the injection of carbon dioxide in the medium containing the food by-product before its pre-concentration by reverse osmosis, preferably in the medium to be treated under low or moderate pressure, at a point at which the velocity of circulation of the liquid medium increases. System for introducing carbon dioxide between the low-moderate pressure pump 4 and the high pressure pump 8 at the entrance of the conical device 7. Application in the pre-concentration by reverse osmosis of food by-products, and in particular the lactoserum.