Process and apparatus for the production of gaseous nitrogen and system for supplying corresponding nitrogen
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorsFrancois Darchis, Francois Venet, Jean-Louis Girault, Maurice Grenier, Patrick Jozon
Life of this patent
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Abstract
As soon as the apparatus is started, a flow of liquid nitrogen which is at least equal to the nominal flow of gaseous nitrogen is introduced in the head portion of the column, then the flow of liquid nitrogen is adjusted to a small fraction of this nominal flow. Application to the production of a flow of gaseous nitrogen which is variable and moderate.
Claims13
A method of producing gaseous nitrogen at variable flow rates by means of air distillation using an HPN air-separation column for producing gaseous nitrogen product and having a head portion and a bottom portion which is fed with compressed air, and wherein liquid nitrogen storage means supplies a flow of liquid nitrogen to the head of the column, and wherein a nominal flow of liquid nitrogen from the storage means is supplied to the head of the column after the column rouses a nominal flow of gaseous nitrogen;
- the improvement comprising sensing the pressure of said gaseous nitrogen product, and selectively modulating the flow of liquid nitrogen supplied from the storage means to the head of the column in a range above said nominal flow of liquid nitrogen in dependence on the sensed pressure, to accommodate variations in the demand for gaseous nitrogen.
Apparatus for the production of gaseous nitrogen at variable flow rates by means of air distillation, comprising an HPN air-separation column for producing gaseous nitrogen product and having a head portion and a bottom portion which is fed with compressed air, and liquid nitrogen storage means supplying a flow of liquid nitrogen to the head of the column, and means to supply a nominal flow of liquid nitrogen from the storage means to the head o the column after the column produces a nominal flow of gaseous nitrogen;
- the improvement comprising means for sensing the pressure of said gaseous nitrogen product, and means for selectively modulating the flow of liquid nitrogen supplied from the storage means to the head of the column in a range above said nominal flow of liquid nitrogen in dependence on the sensed pressure, to accommodate variations in the demand for gaseous nitrogen.
Apparatus for the production of gaseous nitrogen at variable flow rates, comprising:
- an air distillation column having a head portion with a gaseous nitrogen outlet discharging into a product line, a liquid nitrogen inlet, and a bottom portion with a feed air inlet;
- a pressure sensor in the product line, furnishing a pressure signal;
- air feeding means for feeding air to the feed air inlet via a feed air line including a compressor;
- a liquid nitrogen storage means having an outlet, and
- a first liquid nitrogen line between the outlet of the storage means and the liquid nitrogen inlet of the column and including flow control means responsive to the pressure signal.
A network for in situ supply of gaseous nitrogen to at least two remote users, comprising:
- a central unit for the production of large quantities of liquid nitrogen;
- at least one tank truck for remote dispatch of liquid nitrogen produced at the central unit;
- within a first radius around the central unit, at least a vaporizing unit for vaporizing liquid nitrogen, having a liquid nitrogen tank for supplying gaseous nitrogen to a first user;
- within a range between the first radius and a second radius greater than the first radius, at least an apparatus for the production of aseous nitrogen at variable flow rates, for supplying gaseous nitrogen to a second user, the latter apparatus comprising:
- an air distillation column having a head portion with a gaseous nitrogen outlet discharging into a product line, a liquid nitrogen inlet, and a bottom portion with a feed air inlet;
- a pressure sensor in the product line, furnishing a pressure signal;
- air feeding means for feeding air to the feed air inlet via a feed air line including a compressor;
- a liquid nitrogen storage means having an outlet, and
- a first liquid nitrogen line between the outlet of the storage means nd the liquid nitrogen inlet of the column and including flow control means responsive to said pressure signal,
- whereby the liquid nitrogen tank of the vaporizing unit and the liquid nitrogen storage means of the apparatus are periodically refilled from the central unit by the tank truck with liquid nitrogen.
Dependencies are inferred from the claim text.