Process and installation for the production of oxygen and/or nitrogen under pressure at variable flow rate

Abstract

Process and installation for the production of a variable flow rate of at least one principal constituent of air under pressure, of the type in which the constituent is withdrawn in liquid phase from an air distillation apparatus (12), tills liquid is brought to a vaporization pressure, and the liquid is vaporized under this vaporization pressure by heat exchange (in 9; 25) with a calorigenic fluid under pressure. The flow rate of the product constituent is adjusted by modifying the flow rate of the liquid to be vaporized and the vaporization pressure. The vaporization pressure is intermediate the withdrawal pressure and the production pressure, and the gas resulting from the vaporization is compressed to the production pressure (in 20). The modification is effected so as to permit the compressor (20) of the resulting gas to follow its characteristic curve (1), and, to effect this modification, the liquid to be vaporized is throttled in a variable manner (in 18), or the liquid to be vaporized is pumped by a variable speed pump, or the liquid to be vaporized is pumped (in 17) by a constant speed pump, and a variable flow of it is returned (in 24)to the distillation apparatus (12), the rest of the liquid being vaporized.

Dependencies are inferred from the claim text.