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EP0452177A1 - Process and installation for the production of gaseous nitrogen and system for its provision - Google Patents

Process and installation for the production of gaseous nitrogen and system for its provision Download PDF

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Publication number
EP0452177A1
EP0452177A1 EP91400784A EP91400784A EP0452177A1 EP 0452177 A1 EP0452177 A1 EP 0452177A1 EP 91400784 A EP91400784 A EP 91400784A EP 91400784 A EP91400784 A EP 91400784A EP 0452177 A1 EP0452177 A1 EP 0452177A1
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EP
European Patent Office
Prior art keywords
flow
nitrogen
installation
liquid
column
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP91400784A
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German (de)
French (fr)
Other versions
EP0452177B1 (en
Inventor
François Liquid Air Corporation Darchis
François Venet
Jean-Louis Girault
Maurice Grenier
Patrick Jozon
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Application filed by Air Liquide SA, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Air Liquide SA
Publication of EP0452177A1 publication Critical patent/EP0452177A1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/044—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a single pressure main column system only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04012—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling
    • F25J3/04018—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of warm gaseous streams; details of intake or interstage cooling of main feed air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
    • F25J3/04054—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams of air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04812—Different modes, i.e. "runs" of operation
    • F25J3/04818—Start-up of the process
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04812—Different modes, i.e. "runs" of operation
    • F25J3/04824—Stopping of the process, e.g. defrosting or deriming; Back-up procedures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04812—Different modes, i.e. "runs" of operation
    • F25J3/04836—Variable air feed, i.e. "load" or product demand during specified periods, e.g. during periods with high respectively low power costs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/04951—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • F25J3/04951—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network
    • F25J3/04963—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network and inter-connecting equipment within or downstream of the fractionation unit(s)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2210/00—Processes characterised by the type or other details of the feed stream
    • F25J2210/42—Nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/02—Compressor intake arrangement, e.g. filtering or cooling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/40—One fluid being air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/42—One fluid being nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2270/00—Refrigeration techniques used
    • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
    • F25J2270/904—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration by liquid or gaseous cryogen in an open loop
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/60—Details about pipelines, i.e. network, for feed or product distribution
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/62—Details of storing a fluid in a tank
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S62/00—Refrigeration
    • Y10S62/912—External refrigeration system
    • Y10S62/913—Liquified gas

Definitions

  • the present invention relates to the production of nitrogen gas. It relates more particularly to the satisfaction of moderate needs (typically 100 to 1000 Nm3 / h) and variable nitrogen with high purity, that is to say typically containing less than 0.1% oxygen.
  • moderate needs typically 100 to 1000 Nm3 / h
  • variable nitrogen with high purity that is to say typically containing less than 0.1% oxygen.
  • the flow rates considered are mass flow rates.
  • High purity nitrogen is usually obtained cryogenically.
  • the construction of a traditional autonomous production unit represents a prohibitive investment, in the case of automated installations, and a more limited investment but high personnel costs in the opposite case, which always results in a high cost price of nitrogen.
  • a more economical solution consists in using an evaporator, that is to say a tank of liquid nitrogen of large capacity, for example of several tens of thousands of liters, from where the liquid nitrogen is withdrawn and vaporized.
  • This solution is not very satisfactory from an energy point of view, because the refrigerating energy contained in liquid nitrogen is lost, and, moreover, it requires the presence at a relatively short distance of a unit for producing liquid nitrogen, so that the cost of refueling the evaporator by tanker truck remains moderate.
  • the object of the invention is to provide a technique making it possible to produce variable and moderate quantities of nitrogen gas at reduced cost, at increased distances from a unit for producing liquid nitrogen.
  • the object of the invention is a process for the production of nitrogen gas with variable flow at means of an air distillation installation comprising an HPN type air distillation column adapted to produce a nominal flow rate of nitrogen gas and the head of which is connected to a source of liquid nitrogen, characterized in that a flow of liquid nitrogen at least equal to the nominal flow of nitrogen gas is introduced at the start of the installation, at the start of the installation, then the flow of liquid nitrogen is controlled over a small fraction of this nominal flow.
  • HPN air distillation column means a simple distillation column provided with an overhead condenser.
  • the air to be treated compressed under a pressure of the order of 6 to 12 bars, purified with water and CO2 and cooled near its dew point, is introduced at the base of the column.
  • the "rich liquid” (oxygen-enriched air) collected in the column tank is expanded and vaporized in the overhead condenser, then discharged as waste.
  • the nitrogen gas produced is withdrawn at the top of the column.
  • the subject of the invention is also an installation for the production of nitrogen gas with variable flow rate intended for the implementation of such a process.
  • This installation of the type comprising an air distillation column of the HPN type and a liquid nitrogen tank connected by a liquid pipe to the head of the column, is characterized in that said pipe is equipped with control means flow rates adapted on the one hand to let through a high flow of liquid at least equal to the nominal flow of nitrogen gas from the column, and on the other hand to regulate the flow of liquid to an average value equal to a small fraction of this nominal flow.
  • the nitrogen consumption C (Fig. 3 (a)) is constant and equal to the nominal flow DN, and the sensor 19 indicates a constant pressure P (Fig .3 (e)).
  • a line 20 fitted with an all-or-nothing regulation solenoid valve 21 a low average flow rate of liquid nitrogen, equal for example to about 5% of DN (Fig. 3 (b)), is introduced at the head of the column 10 and serves to maintain cold and also to increase the reflux rate of the column.
  • the exchanger 13 is inactive.
  • the incoming air, compressed by the compressor 14, precooled by the air cooler 15, purified in the apparatus 12 and cooled to the vicinity of its dew point in the exchange line 11, is introduced at the base of the column 10.
  • the rich liquid collected in the column tank is expanded in an expansion valve 22, vaporized in the head condenser 23 of the column, heated against the flow of air in the exchange line, then used to regenerate the device 12 before being evacuated via a line 24 as gas residual from the installation.
  • a start of icing may occur in the exchanger 13. This is detected by a temperature sensor 29 disposed on the nitrogen outlet of this exchanger and causes the valve to close. 25.
  • the time T is determined so as to ensure that, whatever the state, hot or cold, of the installation upon restarting, cooling and the correct charge of liquid at each level of the column are obtained.
  • the solenoid valve 30 thus closes at the instant t 7 indicated in FIG. 3.
  • the installation can very easily operate fully automatically despite a very inexpensive structure and means of automation.
  • a flow of nitrogen at least equal to the demand is vaporized in the column, which ensures both the necessary cold supply and the production of nitrogen gas required, and moreover prevents the incoming air to go up the column.
  • the nitrogen arriving in the capacity 18 immediately has the required purity.
  • the two solenoid valves 21 and 30 can be replaced by a single cryogenic valve with variable flow.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

Upon installation start-up there is introduced into the head of the column (10) a flow of liquid nitrogen at least equal to the rated flow of gaseous nitrogen. The flow of liquid nitrogen is then adjusted to a small fraction of this rated flow. …<??>Application to the production of gaseous nitrogen with a variable and moderate flow. …<IMAGE>…

Description

La présente invention est relative à la production d'azote gazeux. Elle concerne plus particulièrement la satisfaction de besoins modérés (typiquement 100 à 1000 Nm³/h) et variables en azote à pureté élevée, c'est à dire contenant typiquement moins de 0,1 % d'oxygène. Dans le présent mémoire, les débits considérés sont des débits massiques.The present invention relates to the production of nitrogen gas. It relates more particularly to the satisfaction of moderate needs (typically 100 to 1000 Nm³ / h) and variable nitrogen with high purity, that is to say typically containing less than 0.1% oxygen. In the present specification, the flow rates considered are mass flow rates.

L'azote à pureté élevée est habituellement obtenu par voie cryogénique. Pour les faibles consommations, la construction d'une unité de production autonome classique représente un investissement prohibitif, dans le cas d'installations automatisées, et un investissement plus limité mais des dépenses en personnel élevées dans le cas inverse, ce qui se traduit toujours par un prix de revient élevé de l'azote.High purity nitrogen is usually obtained cryogenically. For low consumption, the construction of a traditional autonomous production unit represents a prohibitive investment, in the case of automated installations, and a more limited investment but high personnel costs in the opposite case, which always results in a high cost price of nitrogen.

Une solution plus économique consiste à utiliser un évaporateur, c'est-à-dire un réservoir d'azote liquide de grande capacité, par exemple de plusieurs dizaines de milliers de litres, d'où l'azote liquide est soutiré et vaporisé. Cette solution est peu satisfaisante du point de vue énergétique, car l'énergie frigorifique contenue dans l'azote liquide est perdue, et, en outre, elle nécessite la présence à une distance relativement faible d'une unité de production d'azote liquide, pour que le coût du ravitaillement de l'évaporateur par camion-citerne reste modéré.A more economical solution consists in using an evaporator, that is to say a tank of liquid nitrogen of large capacity, for example of several tens of thousands of liters, from where the liquid nitrogen is withdrawn and vaporized. This solution is not very satisfactory from an energy point of view, because the refrigerating energy contained in liquid nitrogen is lost, and, moreover, it requires the presence at a relatively short distance of a unit for producing liquid nitrogen, so that the cost of refueling the evaporator by tanker truck remains moderate.

L'invention a pour but de fournir une technique permettant de produire des quantités variables et modérées d'azote gazeux à coût réduit, à des distances accrues d'une unité de production d'azote liquide.The object of the invention is to provide a technique making it possible to produce variable and moderate quantities of nitrogen gas at reduced cost, at increased distances from a unit for producing liquid nitrogen.

A cet effet, l'invention a pour but un procédé de production d'azote gazeux à débit variable au moyen d'une installation de distillation d'air comprenant une colonne de distillation d'air du type HPN adaptée pour produire un débit nominal d'azote gazeux et dont la tête est reliée à une source d'azote liquide, caractérisé par le fait que l'on introduit en tête de la colonne, dès le démarrage de l'installation, un débit d'azote liquide au moins égal au débit nominal d'azote gazeux, puis on régule le débit d'azote liquide suer une faible fraction de ce débit nominal.To this end, the object of the invention is a process for the production of nitrogen gas with variable flow at means of an air distillation installation comprising an HPN type air distillation column adapted to produce a nominal flow rate of nitrogen gas and the head of which is connected to a source of liquid nitrogen, characterized in that a flow of liquid nitrogen at least equal to the nominal flow of nitrogen gas is introduced at the start of the installation, at the start of the installation, then the flow of liquid nitrogen is controlled over a small fraction of this nominal flow.

Dans le présent mémoire, on entend par "colonne de distillation d'air du type HPN" une simple colonne de distillation munie d'un condenseur de tête. Dans une telle colonne, l'air à traiter, comprimé sous une pression de l'ordre de 6 à 12 bars, épuré en eau et en CO₂ et refroidi au voisinage de son point de rosée, est introduit à la base de la colonne. Le "liquide riche" (air enrichi en oxygène) recueilli en cuve de colonne est détendu et vaporisé dans le condenseur de tête, puis évacué en tant que résiduaire. L'azote gazeux produit est soutiré en tête de colonne.In the present specification, the term "HPN air distillation column" means a simple distillation column provided with an overhead condenser. In such a column, the air to be treated, compressed under a pressure of the order of 6 to 12 bars, purified with water and CO₂ and cooled near its dew point, is introduced at the base of the column. The "rich liquid" (oxygen-enriched air) collected in the column tank is expanded and vaporized in the overhead condenser, then discharged as waste. The nitrogen gas produced is withdrawn at the top of the column.

Suivant des caractéristiques avantageuses de l'invention :

  • on introduit ledit débit nominal pendant un temps au moins égal à une durée prédéterminée et suffisant pour garantir un niveau prédéterminé de liquide réfrigérant dans le condenseur de tête de la colonne ;
  • pour produire un débit d'azote gazeux supérieur au débit nominal, on vaporise à l'extérieur de la colonne un débit d'appoint d'azote liquide provenant de ladite source ;
  • au moins une partie du débit d'appoint est vaporisé par échange de chaleur avec l'air entrant, en amont de l'entrée de cet air dans le compresseur de l'installation.
According to advantageous features of the invention:
  • said nominal flow rate is introduced for a time at least equal to a predetermined duration and sufficient to guarantee a predetermined level of coolant in the head condenser of the column;
  • to produce a flow of nitrogen gas greater than the nominal flow, an additional flow of liquid nitrogen from said source is sprayed outside the column;
  • at least part of the makeup flow is vaporized by heat exchange with the incoming air, upstream of the entry of this air into the installation compressor.

L'invention a également pour objet une installation de production d'azote gazeux à débit variable destinée à la mise en oeuvre d'un tel procédé. Cette installation, du type comprenant une colonne de distillation d'air du type HPN et un réservoir d'azote liquide relié par une conduite de liquide à la tête de la colonne, est caractérisée en ce que ladite conduite est équipée de moyens de commande de débit adaptés d'une part pour laisser passer un fort débit de liquide au moins égal au débit nominal d'azote gazeux de la colonne, et d'autre part pour réguler le débit de liquide sur une valeur moyenne égale à une faible fraction de ce débit nominal.The subject of the invention is also an installation for the production of nitrogen gas with variable flow rate intended for the implementation of such a process. This installation, of the type comprising an air distillation column of the HPN type and a liquid nitrogen tank connected by a liquid pipe to the head of the column, is characterized in that said pipe is equipped with control means flow rates adapted on the one hand to let through a high flow of liquid at least equal to the nominal flow of nitrogen gas from the column, and on the other hand to regulate the flow of liquid to an average value equal to a small fraction of this nominal flow.

L'invention a encore pour objet un système de fourniture d'azote gazeux à de multiples utilisateurs, ce système comprenant :

  • une unité de production d'azote liquide ;
  • au moins un camion-citerne ;
  • dans un premier rayon autour de l'unité de production, une série d'évaporateurs d'azote liquide pouvant être ravitaillés par le camion-citerne ; et
  • entre le premier rayon et un second rayon supérieur au premier, une série d'installations telles que définies ci-dessus, les réservoirs de ces installations pouvant être ravitaillés par le camion-citerne.
Another subject of the invention is a system for supplying nitrogen gas to multiple users, this system comprising:
  • a liquid nitrogen production unit;
  • at least one tank truck;
  • in a first radius around the production unit, a series of liquid nitrogen evaporators that can be supplied by the tanker; and
  • between the first radius and a second radius greater than the first, a series of installations as defined above, the tanks of these installations being able to be supplied by the tank truck.

Un exemple de mise en oeuvre de l'invention va maintenant être décrit en regard des dessins annexés, sur lesquels :

  • la Fig. 1 illustre schématiquement un système de production d'azote gazeux conforme à l'invention ;
  • la Fig. 2 représente schématiquement une installation conforme à l'invention ; et
  • la Fig. 3 est un diagramme illustrant le procédé suivant l'invention.
An example of implementation of the invention will now be described with reference to the accompanying drawings, in which:
  • Fig. 1 schematically illustrates a nitrogen gas production system conforming to the invention;
  • Fig. 2 schematically represents an installation according to the invention; and
  • Fig. 3 is a diagram illustrating the process according to the invention.

Le système de fourniture d'azote gazeux représenté à la Fig. 1 comprend essentiellement :

  • une unité 1 de production d'azote liquide;
  • dans un rayon R1 autour de cette unité, un certain nombre d'évaporateurs d'azote liquide 2, constitués chacun d'un stockage d'azote liquide 3 de grande capacité équipé d'une conduite de soutirage de liquide 4 reliée à une conduite d'utilisation 5 via un vaporiseur 6, par exemple du type atmosphérique. De tels évaporateurs sont bien connus dans la technique ;
  • entre le rayon Rl et un rayon R2 > R1 autour de l'unité 1, un certain nombre d'installations 7 telles que celles de la Fig. 2, chacune de ces installations comprenant un réservoir d'azote liquide 8 ;
  • au moins un camion-citerne 9, et généralement une flottille de tels camions, adapté pour ravitailler en azote liquide produit par l'unité 1 les évaporateurs 2 et les réservoirs 8 des installations 7 ; et éventuellement
  • un système de télétransmission (non représenté) reliant chaque évaporateur 2 et chaque installation 7 à l'unité 1 pour assurer la gestion des livraisons d'azote liquide par le ou les camions-citernes.
The nitrogen gas supply system shown in FIG. 1 essentially includes:
  • a unit 1 for producing liquid nitrogen;
  • in a radius R1 around this unit, a number of liquid nitrogen evaporators 2, each consisting of a large capacity liquid nitrogen storage 3 equipped with a liquid withdrawal line 4 connected to a line d use 5 via a vaporizer 6, for example of the atmospheric type. Such evaporators are well known in the art;
  • between the radius R1 and a radius R2> R1 around the unit 1, a certain number of installations 7 such as those of FIG. 2, each of these installations comprising a liquid nitrogen tank 8;
  • at least one tank truck 9, and generally a fleet of such trucks, suitable for supplying liquid nitrogen produced by the unit 1 the evaporators 2 and the tanks 8 of the installations 7; and eventually
  • a remote transmission system (not shown) connecting each evaporator 2 and each installation 7 to unit 1 to manage the delivery of liquid nitrogen by the tank truck (s).

L'installation 7 représentée à la Fig. 2 comprend essentiellement :

  • le réservoir 8 précité ;
  • une boîte froide 9 contenant d'une part une colonne de distillation d'air 10 du type HPN (High Purity Nitrogen), d'autre part une ligne d'échange thermique 11 ;
  • un appareil 12 d'épuration d'air par adsorption ;
  • un échangeur de chaleur auxiliaire 13 ;
  • un compresseur d'air 14 ; et
  • un aéroréfrigérant 15.
The installation 7 shown in FIG. 2 essentially includes:
  • the aforementioned reservoir 8;
  • a cold box 9 containing on the one hand an air distillation column 10 of the HPN (High Purity Nitrogen) type, on the other hand a heat exchange line 11;
  • an apparatus 12 for purifying air by adsorption;
  • an auxiliary heat exchanger 13;
  • an air compressor 14; and
  • an air cooler 15.

Le fonctionnement de l'installation 7 va maintenant être décrit en regard des Fig. 2 et 3. Sur le diagramme de la Fig. 3, on a porté en abscisses le temps t, et en ordonnées plusieurs paramètres, dont la signification apparaîtra dans la suite.The operation of the installation 7 will now be described with reference to FIGS. 2 and 3. In the diagram of FIG. 3, the time t is plotted on the abscissa and several parameters are plotted on the ordinate, the meaning of which will appear below.

On s'intéresse d'abord au fonctionnement nominal de l'installation, c'est-à-dire à un régime permanent où la colonne 10 produit via la conduite de soutirage 16, piquée en tête de colonne, un débit d'azote gazeux constant égal au débit nominal DN pour lequel la colonne est conçue. La conduite 16 débouche dans une conduite d'utilisation 17 équipée d'une capacité tampon 18 et, en aval de celle-ci, d'un capteur de pression 19.We are first interested in the nominal operation of the installation, that is to say in a steady state where the column 10 produces via the draw-off line 16, tapped at the head of the column, a flow of nitrogen gas constant equal to the nominal flow DN for which the column is designed. Line 16 opens into a use line 17 equipped with a buffer capacity 18 and, downstream of this, a pressure sensor 19.

Dans ce fonctionnement (correspondant à t < t0 sur la Fig.3), la consommation d'azote C (Fig.3(a)) est constante et égale au débit nominal DN, et le capteur 19 indique une pression constante P (Fig.3 (e)). Via une conduite 20 équipée d'une électrovanne 21 de régulation en tout ou rien, un débit moyen faible d'azote liquide, égal par exemple à environ 5 % de DN (Fig.3(b)), est introduit en tête de la colonne 10 et sert à assurer le maintien en froid et également à augmenter le taux de reflux de la colonne. L'échangeur 13 est inactif. L'air entrant, comprimé par le compresseur 14, prérefroidi par l'aéroréfrigérant 15, épuré dans l'appareil 12 et refroidi jusqu'au voisinage de son point de rosée dans la ligne d'échange 11, est introduit à la base de la colonne 10. Le liquide riche recueilli en cuve de colonne est détendu dans une vanne de détente 22, vaporisé dans le condenseur de tête 23 de la colonne, réchauffé à contre-courant de l'air dans la ligne d'échange, puis utilisé pour régénérer l'appareil 12 avant d'être évacué via une conduite 24 en tant que gaz résiduaire de l'installation.In this operation (corresponding to t <t0 in Fig. 3), the nitrogen consumption C (Fig. 3 (a)) is constant and equal to the nominal flow DN, and the sensor 19 indicates a constant pressure P (Fig .3 (e)). Via a line 20 fitted with an all-or-nothing regulation solenoid valve 21, a low average flow rate of liquid nitrogen, equal for example to about 5% of DN (Fig. 3 (b)), is introduced at the head of the column 10 and serves to maintain cold and also to increase the reflux rate of the column. The exchanger 13 is inactive. The incoming air, compressed by the compressor 14, precooled by the air cooler 15, purified in the apparatus 12 and cooled to the vicinity of its dew point in the exchange line 11, is introduced at the base of the column 10. The rich liquid collected in the column tank is expanded in an expansion valve 22, vaporized in the head condenser 23 of the column, heated against the flow of air in the exchange line, then used to regenerate the device 12 before being evacuated via a line 24 as gas residual from the installation.

On supposera qu'à l'instant t0, la consommation (ou demande) d'azote gazeux commence à augmenter (Fig.3(a)). La pression en 19 diminue (Fig.3(e)), ce qui déclenche l'ouverture d'une vanne 25 prévue dans une conduite 26 qui relie le fond du réservoir 8 au bout froid de l'échangeur 13. Un débit DVl d'azote (Fig.3(c)) est ainsi vaporisé en refroidissant à contre-courant l'air entrant jusqu'à une température modérée, par exemple de l'ordre de - 20°C, puis cet azote gazeux est conduit dans la capacité 18. Par suite, le compresseur aspire un débit massique accru d'air, et la production DD (débit distillé) de la colonne augmente (Fig.3(d)). Simultanément, le débit d'azote liquide admis par la conduite 20 augmente quelque peu (Fig.3(b)), pour maintenir constant le niveau de liquide riche dans le condenseur 23.We will assume that at time t 0, the consumption (or demand) of nitrogen gas begins to increase (Fig. 3 (a)). The pressure at 19 decreases (Fig. 3 (e)), which triggers the opening of a valve 25 provided in a pipe 26 which connects the bottom of the tank 8 to the cold end of the exchanger 13. A flow rate DV l nitrogen (Fig. 3 (c)) is thus vaporized by cooling the incoming air against the current to a moderate temperature, for example of the order of - 20 ° C, then this nitrogen gas is led into capacity 18. As a result, the compressor draws in an increased mass flow of air, and the production DD (distilled flow) of the column increases (Fig. 3 (d)). Simultaneously, the flow of liquid nitrogen admitted through line 20 increases somewhat (Fig. 3 (b)), to keep the level of rich liquid in the condenser 23 constant.

Si, de t1 à t2, la consommation continue d'augmenter (Fig.3(a)), une vaporisation supplémentaire d'azote liquide (Fig.3(c)) s'effectue dans un vaporiseur auxiliaire 27, par ouverture d'une vanne 28, sans modifier le débit produit par distillation (Fig.3(d)), puis cet azote gazeux est conduit également dans la capacité 18. Cette ouverture de la vanne 28 se produit lorsque la pression atteint une valeur basse P1 (Fig.3(e)). Le débit total vaporisé DV2, somme des débits vaporisés dans l'échangeur 13 et dans le vaporiseur 27, correspond à l'appoint d'azote nécessaire pour satisfaire la demande. Cette vaporisation d'azote liquide ramène la pression en 19 à la valeur nominale P (Fig.3(e)).If, from t 1 to t 2, the consumption continues to increase (Fig. 3 (a)), an additional vaporization of liquid nitrogen (Fig. 3 (c)) takes place in an auxiliary vaporizer 27, by opening of a valve 28, without modifying the flow rate produced by distillation (Fig. 3 (d)), then this nitrogen gas is also led into the capacity 18. This opening of the valve 28 occurs when the pressure reaches a value low P1 (Fig. 3 (e)). The total vaporized flow rate DV2, the sum of the flow rates vaporized in the exchanger 13 and in the vaporizer 27, corresponds to the addition of nitrogen necessary to satisfy the demand. This vaporization of liquid nitrogen reduces the pressure at 19 to the nominal value P (Fig. 3 (e)).

Il est à noter qu'après un certain temps, un début de givrage peut se produire dans l'échangeur 13. Ceci est détecté par un capteur de température 29 disposé sur la sortie d'azote de cet échangeur et provoque la fermeture de la vanne 25.It should be noted that after a certain time, a start of icing may occur in the exchanger 13. This is detected by a temperature sensor 29 disposed on the nitrogen outlet of this exchanger and causes the valve to close. 25.

Lorsque, après une phase de stabilisation (de t2 à t3), la consommation baisse, la pression en 19 monte, ce qui déclenche l'arrêt de la vaporisation d'azote (fermeture des vannes 25 et 28), puis, quand la pression atteint une valeur haute P2, l'arrêt de l'installation, notamment du compresseur 14 (instant t4).When, after a stabilization phase (from t 2 to t 3), the consumption decreases, the pressure at 19 rises, which triggers the stopping of the nitrogen vaporization (closing of the valves 25 and 28), then, when the pressure reaches a high value P2, stopping the installation, in particular of the compressor 14 (instant t 4).

Lorsque la consommation d'azote gazeux reprend (instant t5), la pression baisse, et lorsqu'elle atteint la valeur nominale P1 (instant t6), une électrovanne de démarrage 30, montée en by-pass de l'électrovanne 21 et normalement fermée, s'ouvre. Cette électrovanne 30 est adaptée pour, en position ouverte, laisser passer un débit d'azote liquide au moins égal au débit nominal DN. Sa fermeture a lieu lorsque deux conditions sont remplies :

  • (a) un temps prédeterminé T s'est écoulé depuis son ouverture ; et
  • (b) le niveau du liquide riche dans le condenseur 23 est au moins égal à une valeur prédéterminée.
When the consumption of nitrogen gas resumes (instant t 5), the pressure drops, and when it reaches the nominal value P1 (instant t 6), a starting solenoid valve 30, mounted in by-pass of the solenoid valve 21 and normally closed, opens. This solenoid valve 30 is suitable for, in the open position, allowing a flow of liquid nitrogen at least equal to the nominal flow DN to pass. It closes when two conditions are met:
  • (a) a predetermined time T has elapsed since its opening; and
  • (b) the level of the rich liquid in the condenser 23 is at least equal to a predetermined value.

Le temps T est déterminé de façon à assurer que, quel que soit l'état, chaud ou froid, de l'intallation au moment du redémarrage, la mise en froid et la charge correcte de liquide à chaque niveau de la colonne sont obtenus. On peut par exemple choisir un temps T de l'ordre de 2 minutes.The time T is determined so as to ensure that, whatever the state, hot or cold, of the installation upon restarting, cooling and the correct charge of liquid at each level of the column are obtained. We can for example choose a time T of the order of 2 minutes.

L'électrovanne 30 se ferme ainsi à l'instant t7 indiqué sur la Fig. 3.The solenoid valve 30 thus closes at the instant t 7 indicated in FIG. 3.

On a également représenté à la Fig. 3 des instant t8 < t7 et t9 > t7 pour lesquels, respectivement, la consommation C augmente au delà de la valeur nominale puis se stabilise, les mêmes phénomènes que décrits ci-dessus se reproduisant alors automatiquement (vaporisation d'azote et variations de la pression et du débit d'azote produit par la colonne).Also shown in FIG. 3 of the instant t 8 < t 7 and t 9> t 7 for which, respectively, the consumption C increases beyond the nominal value then stabilizes, the same phenomena as described above then reproducing automatically (vaporization of nitrogen and variations in pressure and nitrogen flow produced by the column).

On voit donc que l'installation peut très facilement fonctionner de façon entièrement automatique malgré une structure et des moyens d'automatisation très peu coûteux. En particulier, dès le démarrage, un débit d'azote au moins égal à la demande est vaporisé dans la colonne, ce qui assure à la fois l'apport de froid nécessaire et la production d'azote gazeux demandée, et de plus empêche l'air entrant de monter dans la colonne. Par suite, l'azote arrivant dans la capacité 18 a immédiatement la pureté requise.It can therefore be seen that the installation can very easily operate fully automatically despite a very inexpensive structure and means of automation. In particular, from the start, a flow of nitrogen at least equal to the demand is vaporized in the column, which ensures both the necessary cold supply and the production of nitrogen gas required, and moreover prevents the incoming air to go up the column. As a result, the nitrogen arriving in the capacity 18 immediately has the required purity.

En variante, les deux électrovannes 21 et 30 peuvent être remplacées par une vanne cryogénique unique à débit variable.Alternatively, the two solenoid valves 21 and 30 can be replaced by a single cryogenic valve with variable flow.

On remarque que l'installation n'a besoin, pour fonctionner, que d'un branchement électrique, ce qui a été symbolisé sur la Fig. 1.It is noted that the installation only needs to have an electrical connection to operate, which has been symbolized in FIG. 1.

Claims (9)

Procédé de production d'azote gazeux à débit variable au moyen d'une installation de distillation d'air (7) comprenant une colonne (10) de distillation d'air du type HPN adaptée pour produire un débit nominal (DN) d'azote gazeux et dont la tête est reliée à une source d'azote liquide (8), caractérisé en ce qu'on introduit en tête de la colonne, dès le démarrage de l'installation, un débit d'azote liquide au moins égal au débit nominal (DN) d'azote gazeux, puis on régule le débit d'azote liquide sur une faible fraction de ce débit nominal.Method for producing nitrogen gas with variable flow rate by means of an air distillation installation (7) comprising an air distillation column (10) of the HPN type suitable for producing a nominal flow rate (DN) of nitrogen gaseous and the head of which is connected to a source of liquid nitrogen (8), characterized in that, at the start of the installation, a flow of liquid nitrogen at least equal to the flow is introduced at the start of the installation nominal (DN) of nitrogen gas, then regulate the flow of liquid nitrogen over a small fraction of this nominal flow. Procédé suivant la revendication 1, caractérisé en ce qu'on introduit ledit débit nominal (DN) pendant un temps au moins égal à une durée prédéterminée et suffisant pour garantir un niveau prédéterminé de liquide réfrigérant dans le condenseur de tête (23) de la colonne (10).Method according to Claim 1, characterized in that the said nominal flow (DN) is introduced for a time at least equal to a predetermined duration and sufficient to guarantee a predetermined level of coolant in the head condenser (23) of the column (10). Procédé suivant la revendication 1 ou 2, caractérisé en ce que pour produire un débit d'azote gazeux supérieur au débit nominal (DN), on vaporise à l'extérieur de la colonne un débit d'appoint d'azote liquide provenant de ladite source (8).Process according to claim 1 or 2, characterized in that to produce a flow of nitrogen gas greater than the nominal flow (DN), an additional flow of liquid nitrogen from said source is vaporized outside the column. (8). Procédé suivant la revendication 3, caractérisé en ce qu'au moins une partie du débit d'appoint est vaporisé par échange de chaleur avec l'air entrant, en amont de l'entrée de cet air dans le compresseur (14) de l'installation.Method according to claim 3, characterized in that at least part of the make-up flow is vaporized by heat exchange with the incoming air, upstream of the entry of this air into the compressor (14) of the installation. Installation de production d'azote gazeux à débit variable, du type comprenant une colonne de distillation d'air (10) du type HPN et un réservoir d'azote liquide (8) relié par une conduite de liquide (20) à la tête de la colonne, caractérisée en ce que ladite conduite (20) est équipée de moyens de commande de débit (21, 30) adaptés d'une part pour laisser passer un fort débit de liquide au moins égal au débit nominal (DN) d'azote gazeux de la colonne, et d'autre part pour réguler le débit de liquide sur une valeur moyenne égale à une faible fraction de ce débit nominal.Installation for the production of gaseous nitrogen with variable flow rate, of the type comprising an air distillation column (10) of the HPN type and a liquid nitrogen tank (8) connected by a liquid line (20) to the head of the column, characterized in that said pipe (20) is equipped with control means flow (21, 30) adapted on the one hand to allow a high flow of liquid at least equal to the nominal flow (DN) of nitrogen gas from the column, and on the other hand to regulate the flow of liquid on a average value equal to a small fraction of this nominal flow. Installation suivant la revendication 5, caractérisée en ce que lesdits moyens de commande de débit comprennent, en parallèle, d'une part une première électrovanne (30) adaptée pour laisser passer, en position ouverte, ledit fort débit de liquide, et d'autre part une seconde électrovanne (21) adaptée pour laisser passer, en position ouverte, un débit de liquide nettement plus faible.Installation according to claim 5, characterized in that said flow control means comprise, in parallel, on the one hand a first solenoid valve (30) adapted to allow said high liquid flow to pass, in the open position, and on the other hand share a second solenoid valve (21) adapted to let through, in the open position, a significantly lower liquid flow rate. Installation suivant la revendication 5 ou 6, caractérisée en ce qu'elle comprend une conduite de vaporisation d'azote d'appoint reliant le fond du réservoir (8) à une conduite de production (17) de l'installation via un vaporiseur (13, 27).Installation according to claim 5 or 6, characterized in that it comprises an additional nitrogen vaporization line connecting the bottom of the tank (8) to a production line (17) of the installation via a vaporizer (13 , 27). Installation suivant la revendication 7, caractérisée en ce que le vaporiseur comprend un échangeur de chaleur (13) traversé d'une part par l'azote à vaporiser, d'autre part par l'air entrant, avant l'entrée de celui-ci dans le compresseur (14) de l'installation.Installation according to claim 7, characterized in that the vaporizer comprises a heat exchanger (13) traversed on the one hand by the nitrogen to be vaporized, on the other hand by the incoming air, before the entry thereof in the compressor (14) of the installation. Système de fourniture d'azote gazeux à de multiples utilisateurs, caractérisé en ce qu'il comprend : - une unité (1) de production d'azote liquide ; - au moins un camion-citerne (9) ; - dans un premier rayon (R1) autour de l'unité de production, une série d'évaporateurs d'azote liquide (2) pouvant être ravitaillés par le camion-citerne ; et - entre le premier rayon (R1) et un second rayon (R2) supérieur au premier, une série d'installations (7) conformes à l'une quelconque des revendications 5 à 8, les réservoirs (8) de ces installations pouvant être ravitaillés par le camion-citerne. System for supplying nitrogen gas to multiple users, characterized in that it comprises: - a unit (1) for producing liquid nitrogen; - at least one tank truck (9); - in a first radius (R1) around the production unit, a series of liquid nitrogen evaporators (2) which can be supplied by the tanker ; and - Between the first radius (R1) and a second radius (R2) greater than the first, a series of installations (7) according to any one of Claims 5 to 8, the tanks (8) of these installations being able to be refueled by the tanker.
EP91400784A 1990-04-10 1991-03-22 Process and installation for the production of gaseous nitrogen and system for its provision Expired - Lifetime EP0452177B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9004566A FR2660741A1 (en) 1990-04-10 1990-04-10 PROCESS AND PLANT FOR GENERATING GASEOUS NITROGEN AND CORRESPONDING NITROGEN SUPPLY SYSTEM THEREFOR.
FR9004566 1990-04-10

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EP0452177A1 true EP0452177A1 (en) 1991-10-16
EP0452177B1 EP0452177B1 (en) 1995-04-19

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US (1) US5157927A (en)
EP (1) EP0452177B1 (en)
JP (1) JP3231799B2 (en)
AU (1) AU642991B2 (en)
CA (1) CA2039939A1 (en)
DE (1) DE69108973T2 (en)
ES (1) ES2071246T3 (en)
FR (1) FR2660741A1 (en)
ZA (1) ZA912591B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997041400A1 (en) * 1996-04-30 1997-11-06 Linde Aktiengesellschaft Process for starting an installation for low temperature air decomposition and installation for low temperature air decomposition
WO2006003138A1 (en) 2004-06-29 2006-01-12 L'air Liquide Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the emergency back-up supply of a gas under pressure
WO2007074276A2 (en) 2005-12-20 2007-07-05 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Air separating device by means of cryogenic distillation
FR2903483A1 (en) * 2006-07-04 2008-01-11 Air Liquide METHOD AND APPARATUS FOR AIR SEPARATION BY CRYOGENIC DISTILLATION
US7444834B2 (en) 2003-04-02 2008-11-04 L'air Liquide, Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the provision of gas under pressure
US7870759B2 (en) 2003-05-28 2011-01-18 L'air Liquide, Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and arrangement for the backup supply of a pressurized gas through cryogenic liquid vaporization
FR3119225A1 (en) 2021-01-27 2022-07-29 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the emergency supply of a gas

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5233839A (en) * 1991-03-13 1993-08-10 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process for operating a heat exchanger
FR2694383B1 (en) * 1992-07-29 1994-09-16 Air Liquide Production and installation of nitrogen gas production with several different purities.
FR2696821B1 (en) * 1992-10-09 1994-11-10 Air Liquide Process and installation for producing ultra-pure nitrogen under pressure.
FR2697620B1 (en) * 1992-10-30 1994-12-23 Air Liquide Process and installation for the production of nitrogen gas with variable flow.
JP3447437B2 (en) * 1995-07-26 2003-09-16 日本エア・リキード株式会社 High-purity nitrogen gas production equipment
FR2862746B1 (en) * 2003-11-25 2007-01-19 Air Liquide METHOD AND INSTALLATION OF AIR SEPARATION BY CRYOGENIC DISTILLATION
FR2906878A1 (en) * 2007-01-09 2008-04-11 Air Liquide Nitrogen supplying method, involves sending liquid nitrogen towards separating apparatus for partially maintaining cooling of apparatus, during operating period, and conveying liquid nitrogen flow to vaporizer during another period
FR2913104B1 (en) * 2007-02-28 2009-11-27 Air Liquide PROCESS AND APPARATUS FOR SUPPLYING NITROGEN.
CN106016794B (en) * 2016-05-20 2019-02-19 上海优华系统集成技术股份有限公司 A system and method for recycling waste heat of aromatic hydrocarbon plant
JP7385800B1 (en) * 2023-03-29 2023-11-24 レール・リキード－ソシエテ・アノニム・プール・レテュード・エ・レクスプロワタシオン・デ・プロセデ・ジョルジュ・クロード Heat exchanger control system and method for low temperature equipment, and air separation device equipped with the system

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FR2225705A1 (en) * 1973-04-13 1974-11-08 Cryoplants Ltd
EP0190355A1 (en) * 1984-07-13 1986-08-13 Daidousanso Co., Ltd. Apparatus for producing high-purity nitrogen gas

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JPS6124968A (en) * 1984-07-13 1986-02-03 大同酸素株式会社 Production unit for high-purity nitrogen gas
JPS61190277A (en) * 1985-02-16 1986-08-23 大同酸素株式会社 High-purity nitrogen and oxygen gas production unit

Patent Citations (2)

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Publication number Priority date Publication date Assignee Title
FR2225705A1 (en) * 1973-04-13 1974-11-08 Cryoplants Ltd
EP0190355A1 (en) * 1984-07-13 1986-08-13 Daidousanso Co., Ltd. Apparatus for producing high-purity nitrogen gas

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997041400A1 (en) * 1996-04-30 1997-11-06 Linde Aktiengesellschaft Process for starting an installation for low temperature air decomposition and installation for low temperature air decomposition
US7444834B2 (en) 2003-04-02 2008-11-04 L'air Liquide, Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the provision of gas under pressure
US7870759B2 (en) 2003-05-28 2011-01-18 L'air Liquide, Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and arrangement for the backup supply of a pressurized gas through cryogenic liquid vaporization
WO2006003138A1 (en) 2004-06-29 2006-01-12 L'air Liquide Societe Anonyme A Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the emergency back-up supply of a gas under pressure
WO2007074276A2 (en) 2005-12-20 2007-07-05 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Air separating device by means of cryogenic distillation
FR2903483A1 (en) * 2006-07-04 2008-01-11 Air Liquide METHOD AND APPARATUS FOR AIR SEPARATION BY CRYOGENIC DISTILLATION
WO2008003585A3 (en) * 2006-07-04 2009-01-15 Air Liquide Air separation process and apparatus using cryogenic distillation
FR3119225A1 (en) 2021-01-27 2022-07-29 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Method and installation for the emergency supply of a gas

Also Published As

Publication number Publication date
DE69108973D1 (en) 1995-05-24
ZA912591B (en) 1992-01-29
JP3231799B2 (en) 2001-11-26
FR2660741A1 (en) 1991-10-11
FR2660741B1 (en) 1995-04-28
US5157927A (en) 1992-10-27
AU642991B2 (en) 1993-11-04
ES2071246T3 (en) 1995-06-16
EP0452177B1 (en) 1995-04-19
AU7418191A (en) 1991-10-17
DE69108973T2 (en) 1995-08-31
JPH0587446A (en) 1993-04-06
CA2039939A1 (en) 1991-10-11

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