Abstract: During the recycling operation, the carrier gas is subjected to a pre-purification prior to the conventional purification, the flow rate and the pressure of the carrier gas being maintained at strictly constant values at the inlet of the chromatographic unit. The method is primarily applicable to low-pressure gas chromatography and permits finer separations as well as higher productivity than atmospheric-pressure chromatography.

Abstract: An electrolysis apparatus formed by a stack of cells which are held together by two end-plates connected by tie-rods, wherein a system comprising two kinds of elements provides, firstly, electrical insulation between pairs of adjoining rings and secondly a seal to prevent the electrolyte from escaping to the exterior. Such an apparatus further comprises a system of ducts formed by stacks of bushes which are assembled to form a piping, wherein said bushes are sealed to the diaphragm and bears against adjoining bushes via a joint which is contact with an electrode, the bushes forming the infeed ducts being perced with one or more small diameter passages, the bushes forming the outlet ducts being perced with passages which cause a much smaller pressure loss.

Abstract: A quick-start electrolysis apparatus which is started up by means of an electrical supply circuit comprising regulating means for increasing the current intensity flowing through the apparatus in an exponential fashion as a function of time so that the ratio between the volume of gas and the volume of electrolyte is maintained constant.

Abstract: The invention relates to an apparatus for the electrolysis of water which operates under pressure and can be started up without injecting nitrogen. A set of valves arranged in the electrolyte circulation circuit upstream and downstream of the stack of electrolytic cells isolates the stack from the remainder of the apparatus when the apparatus has finished operations, with the result that a specific pressure is maintained within the cells until the apparatus is next started up.