[go: up one dir, main page]

EP0768503B1 - Triple column air separation process - Google Patents

Triple column air separation process Download PDF

Info

Publication number
EP0768503B1
EP0768503B1 EP96116124A EP96116124A EP0768503B1 EP 0768503 B1 EP0768503 B1 EP 0768503B1 EP 96116124 A EP96116124 A EP 96116124A EP 96116124 A EP96116124 A EP 96116124A EP 0768503 B1 EP0768503 B1 EP 0768503B1
Authority
EP
European Patent Office
Prior art keywords
pressure
pressure column
column
medium
low
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.)
Expired - Lifetime
Application number
EP96116124A
Other languages
German (de)
French (fr)
Other versions
EP0768503A3 (en
EP0768503A2 (en
Inventor
Jürgen Dipl.-Phys. Voit
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.)
Linde GmbH
Original Assignee
Linde GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Linde GmbH filed Critical Linde GmbH
Publication of EP0768503A2 publication Critical patent/EP0768503A2/en
Publication of EP0768503A3 publication Critical patent/EP0768503A3/en
Application granted granted Critical
Publication of EP0768503B1 publication Critical patent/EP0768503B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
    • F25J3/04303—Lachmann expansion, i.e. expanded into oxygen producing or low pressure column
    • 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
    • F25J3/04436—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 at least a triple pressure main column system
    • F25J3/04448—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 at least a triple pressure main column system in a double column flowsheet with an intermediate pressure column
    • 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
    • F25J3/04872—Vertical layout of cold equipments within in the cold box, e.g. columns, heat exchangers etc.
    • F25J3/04878—Side by side arrangement of multiple vessels in a main column system, wherein the vessels are normally mounted one upon the other or forming different sections of the same column
    • 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
    • Y10S62/90—Triple column
    • 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
    • Y10S62/939—Partial feed stream expansion, air

Definitions

  • the invention relates to a method for the low-temperature separation of air in one Triple column system consisting of a high pressure column, a medium pressure column and a low pressure column, with the steps listed in claim 1 (a) to (i).
  • a triple column system has at least three columns for nitrogen-oxygen separation on.
  • the term includes systems and processes that serve as additional pillars Nitrogen-oxygen separation and / or for the extraction of others Have air components such as noble gases, for example a crude argon column.
  • Triple column process of the type mentioned above is known from DE-A-2903089, The entire feed air is compressed to a first pressure, which is above the Medium pressure column pressure, and some without further pressure changing Measures fed into the medium pressure column, to another part on one second pressure further compressed and introduced into the high pressure column. The rest of compressed service air is relieved of work and into the low pressure column introduced. However, this process does not work optimally in terms of energy.
  • the invention is therefore based on the object of a method of the beginning specified type with particularly high efficiency.
  • This object is achieved in that the first pressure is lower than that Operating pressure of the medium pressure column and that the second part of the feed air from the first pressure is compressed to a third pressure that is at least equal to that Operating pressure of the medium pressure column, but is lower than the second pressure.
  • the total amount of feed air is therefore only at a relatively low pressure compressed, which is lower than the pressure prevailing in the medium pressure column.
  • the in the first air section to be introduced must be in a further one Compressors are compressed correspondingly higher; the part of the feed air that anyway directly under the low pressure column working at lower pressure is fed in, but does not even need to the high pressure of the High pressure column to be brought.
  • the cooling needs of the System is relatively small, for example, because a small part of the products are liquid is obtained or it is a pure gas system, results in particularly low energy consumption.
  • relaxation is preferably between the first pressure and the Pressure of the medium pressure column.
  • the third part of the air should relax during work gained energy or a part thereof for the compression of the third air part be used.
  • the post-compressor is preferably used exclusively for this internally generated mechanical energy is driven so that it does not come from the outside energy consumed.
  • Post-compressor and expansion machine are for example mechanically coupled via a common shaft.
  • the high pressure column can be relatively low operated low pressure, which is preferably 4.8 bar or less. This results in a particularly low effort when compressing the feed air.
  • the low pressure column is preferably under the lowest possible pressure operated. This is determined by the fact that the top product of the low pressure column - if necessary after passing through one or more heat exchangers - under im substantial atmospheric pressure can be removed from the process; if this top product as regeneration gas in a cleaning device (e.g. one Molecular sieve system) is used, the pressure of the low pressure column must also enable their operation.
  • a cleaning device e.g. one Molecular sieve system
  • part of the first oxygen-enriched bottom fraction is introduced from the high pressure column into the medium pressure column. It becomes a part of the bottom product from the high pressure column, and thus one larger amount of nitrogen-enriched fraction at the top of the medium pressure column won, which is available as return liquid in the low pressure column. This further improves rectification in the low pressure column.
  • the bottom fraction from the high pressure column is preferably at an intermediate point introduced into the medium pressure column, that is at a point that has at least one practical or theoretical floor above the sump of the medium pressure column and in particular at least one practical or theoretical floor above the point where the second air part is fed into the medium pressure column.
  • the invention also relates to a device for the low temperature decomposition of Air according to claim 8.
  • Nitrogen will be produced if there is an additional one at the top of the low pressure column Ordinary pure nitrogen section is arranged.
  • Argon production is also possible if the low pressure column in a known manner (see for example EP-B-377117) an argon rectification is connected downstream. Likewise, other noble gases are generated in a known manner.
  • Feed air 1 is compressed in a main air compressor 2 to a first pressure.
  • the compressed feed air 3 is in a first partial flow 101, a second partial flow 201 and a third partial stream 301 divided.
  • the first partial flow to a second pressure and the second partial flow to one brought between the first and the second pressure third pressure.
  • there the first partial flow and the second partial flow are initially together (4) in Compressor 5 to the third pressure and then the first partial flow 101 alone further compressed in the compressor 102 to the second pressure.
  • you can the first and the second partial stream can also be compressed independently of one another.
  • the third partial stream, the Relaxation machine 305 or the post-compressor 302 fed will be branched downstream of one of the compressors 5 or 102.
  • the cooling capacity achieved with this can increase the pressure when relaxing increased and / or the amount of air blown directly into the low pressure column be reduced.
  • the first partial flow 103 under the second pressure and that under the third Second partial flow 201 under pressure is counteracted in a main heat exchanger 6
  • the high pressure column 7 is under operated at a pressure of 4.5 to 5.5 bar, preferably 4.6 to 4.8 bar
  • Medium pressure column 8 is under 2.5 to 3.5 bar, preferably 2.8 to 3.0 bar.
  • the first pressure (in line 3 behind the main air compressor 2) is significantly lower as the high pressure column pressure; the difference is at least 2.5 bar, preferably 3.0 to 3.2 bar.
  • the second pressure is slightly above that High pressure column pressure (for example about 0.1 bar above the pressure at the Feeding point in the high pressure column) to the pressure drop in the main heat exchanger 6 and equalize in lines 103 and 104.
  • the third pressure is analogous to this (downstream of the compressor 5) slightly above the pressure of the medium pressure column the introduction of the second partial flow 201, 202 into the medium pressure column 8 guarantee.
  • the third partial flow 301 is optionally in a post-compressor 302 on a fourth pressure, which is between the first pressure and the operating pressure the medium pressure column can be, for example, 1.5 to 2.5 bar higher than that first print is.
  • the fourth pressure is correspondingly higher means for example higher than the pressure of the medium pressure column or even higher than the pressure of the high pressure column; in this case it can be up to 8 bar or more
  • Via line 303 it goes to the main heat exchanger 6 and from it cold end from further (304) to the relaxation machine 305.
  • the work-performing relaxed air 306 is introduced into the low-pressure column 9 at medium height.
  • each compressor 2, 5, 102, 302 in indirect heat exchange cooled with cooling water, as by the aftercoolers shown in the drawing is indicated.
  • a first nitrogen-enriched precipitate Head fraction as head gas and a first oxygen-enriched fraction as Sump liquid is in a first condenser-evaporator 11 condensed and in part 12 in the high pressure column and in another part 13 - if necessary after subcooling in counterflow 14 - via line 15 in the Low pressure column 9 throttled (16), the operating pressure 1.1 to 1.5 bar, preferably 1.2 to 1.4 bar.
  • Part of the condensed nitrogen enriched Fraction 13 from the high pressure column can via the optional line 17 to the top of the Medium pressure column 8 are performed.
  • the bottom liquid of the high pressure column is over Line 18 also into the low pressure column 9 after optional subcooling (14) relaxed (19, 20).
  • the feed point is above that of the work-performing relaxed air 306.
  • the feed point is at least one practical or theoretical floor, preferably two to five theoretical plates above the feed of the second Air section 202.
  • a second nitrogen-enriched head fraction and won a second oxygen-enriched sump liquid In the medium pressure column 8, a second nitrogen-enriched head fraction and won a second oxygen-enriched sump liquid.
  • the head gas 21 will condensed in a second condenser-evaporator 22 and to a first part 23 in the medium pressure column and to a second part 24 - if necessary after Hypothermia in counterflow 14 - throttled into low-pressure column 9 (25).
  • the Bottom liquid of the medium pressure column is also optional via line 26 Hypothermia (14) in the evaporation space of the second condenser-evaporator 22 relaxed (27).
  • the vaporized stream 28 is introduced into the low pressure column 9 (29).
  • the feed point for example, at the same level as that of the Bottom liquid from the high pressure column or something above it.
  • the cleaning of the feed air is not shown in the drawing. You can by each of the known methods take place, for example in a switchable Heat exchanger (Revex) or in one or more molecular sieve systems. in the the latter case, it is possible to collectively use the entire feed air (line 3) Subject to cleaning, the three substreams 103, 201, 303 in separate systems treat or the first and second partial stream together through one arranged immediately downstream of the aftercooler of the compressor 5 Molecular sieve. In the event that different from the representation in the Drawing of the third partial flow behind one of the compressors 5 or 102 removed and is fed to the post-compressor 302, all three partial flows or at least the first and the third partial stream are cleaned together.
  • the mass transfer elements in the High pressure column and those formed in the medium pressure column by still bottoms in the low pressure column by orderly packing. Basically, however, at of the invention in each of the columns conventional still bottoms (disordered packing) and / or ordered packing. Also Combinations of different elements in one column are possible. Because of the low pressure drop, ordered packings in all columns, in particular in the low pressure column, preferred. These increase the energy-saving effect the invention further.

Landscapes

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

Description

Die Erfindung betrifft ein Verfahren zur Tieftemperaturzerlegung von Luft in einem Dreifachsäulensystem, das aus einer Hochdrucksäule, einer Mitteldrucksäule und einer Niederdrucksäule besteht, mit den im Patentanspruch 1 angeführten Schritten (a) bis (i).The invention relates to a method for the low-temperature separation of air in one Triple column system consisting of a high pressure column, a medium pressure column and a low pressure column, with the steps listed in claim 1 (a) to (i).

Ein Dreifachsäulensystem weist mindestens drei Säulen zur Stickstoff-Sauerstoff-Trennung auf. Der Begriff schließt Anlagen und Verfahren ein, die weitere Säulen zur Stickstoff-Sauerstoff-Trennung und/oder zur Gewinnung von anderen Luftbestandteilen wie Edelgasen aufweisen, beispielsweise eine Rohargonsäule. Ein Dreifachsäulenverfahren der oben genannten Art ist aus der DE-A-2903089 bekannt, Die gesamte Einsatzluft wird hier auf einen ersten Druck verdichtet, der über dem Mitteldrucksäulendruck liegt, und zu einem Teil ohne weitere druckverändemde Maßnahmen in die Mitteldrucksäule eingespeist, zu einem anderen Teil auf einen zweiten Druck weiter verdichtet und in die Hochdrucksäule eingeführt. Der Rest der verdichteten Einsatzluft wird arbeitsleistend entspannt und in die Niederdrucksäule eingeführt. Dieses Verfahren arbeitet jedoch energetisch nicht vollständig optimal.A triple column system has at least three columns for nitrogen-oxygen separation on. The term includes systems and processes that serve as additional pillars Nitrogen-oxygen separation and / or for the extraction of others Have air components such as noble gases, for example a crude argon column. On Triple column process of the type mentioned above is known from DE-A-2903089, The entire feed air is compressed to a first pressure, which is above the Medium pressure column pressure, and some without further pressure changing Measures fed into the medium pressure column, to another part on one second pressure further compressed and introduced into the high pressure column. The rest of compressed service air is relieved of work and into the low pressure column introduced. However, this process does not work optimally in terms of energy.

Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren der eingangs genannten Art mit besonders hohem Wirkungsgrad anzugeben.The invention is therefore based on the object of a method of the beginning specified type with particularly high efficiency.

Diese Aufgabe wird dadurch gelöst, daß der erste Druck niedriger als der Betriebsdruck der Mitteldrucksäule ist und daß der zweite Teil der Einsatzluft von dem ersten Druck auf einen dritten Druck verdichtet wird, der mindestens gleich dem Betriebsdruck der Mitteldrucksäule, aber niedriger als der zweite Druck ist.This object is achieved in that the first pressure is lower than that Operating pressure of the medium pressure column and that the second part of the feed air from the first pressure is compressed to a third pressure that is at least equal to that Operating pressure of the medium pressure column, but is lower than the second pressure.

Die Gesamtmenge der Einsatzluft wird also nur auf einen relativ niedrigen Druck verdichtet, der geringer als der in der Mitteldrucksäule herrschende Druck ist. Der in die Mitteldrucksäule einzuführende erste Luftteil muß zwar in einem weiteren Verdichter entsprechend höher verdichtet werden; derjenige Teil der Einsatzluft, der ohnehin direkt unter die bei geringerem Druck arbeitende Niederdrucksäule eingespeist wird, braucht jedoch gar nicht erst auf den hohen Druck der Hochdrucksäule gebracht zu werden. Insbesondere dann, wenn der Kältebedarf der Anlage relativ gering ist, weil beispielsweise ein geringer Teil der Produkte flüssig gewonnen wird oder es sich um eine reine Gasanlage handelt, ergibt sich ein besonders niedriger Energieverbrauch.The total amount of feed air is therefore only at a relatively low pressure compressed, which is lower than the pressure prevailing in the medium pressure column. The in the first air section to be introduced must be in a further one Compressors are compressed correspondingly higher; the part of the feed air that anyway directly under the low pressure column working at lower pressure is fed in, but does not even need to the high pressure of the High pressure column to be brought. Especially when the cooling needs of the System is relatively small, for example, because a small part of the products are liquid is obtained or it is a pure gas system, results in particularly low energy consumption.

Dabei ist es günstig, wenn der dritte Teil der Einsatzluft stromaufwärts der arbeitsleistenden Entspannung nachverdichtet wird, um die Druckdifferenz bei der arbeitsleistenden Entspannung zu erhöhen. Der Druck beim Eintritt in die arbeitsleistende Entspannung liegt in diesem Fall vorzugsweise zwischen dem ersten Druck und dem Druck der Mitteldrucksäule.It is advantageous if the third part of the feed air upstream of the work Relaxation is post-compressed to the pressure difference at the job-performing Increase relaxation. The pressure when entering the job-performing In this case, relaxation is preferably between the first pressure and the Pressure of the medium pressure column.

In diesem Fall sollte die bei der arbeitsleistenden Entspannung des dritten Luftteils gewonnene Energie oder ein Teil davon zur Nachverdichtung des dritten Luftteils verwendet werden. Vorzugsweise wird der Nachverdichter ausschließlich durch diese intern erzeugte mechanische Energie angetrieben, so daß er keine von außen eingebrachte Energie verbraucht. Nachverdichter und Entspannungsmaschine sind beispielsweise über eine gemeinsame Welle mechanisch gekoppelt.In this case, the third part of the air should relax during work gained energy or a part thereof for the compression of the third air part be used. The post-compressor is preferably used exclusively for this internally generated mechanical energy is driven so that it does not come from the outside energy consumed. Post-compressor and expansion machine are for example mechanically coupled via a common shaft.

Bei dem erfindungsgemäßen Verfahren kann die Hochdrucksäule unter einem relativ niedrigen Druck betrieben werden, der vorzugsweise bei 4,8 bar oder weniger liegt. Damit ergibt sich ein besonders geringer Aufwand beim Verdichten der Einsatzluft.In the method according to the invention, the high pressure column can be relatively low operated low pressure, which is preferably 4.8 bar or less. This results in a particularly low effort when compressing the feed air.

Die Niederdrucksäule wird vorzugsweise unter dem niedrigstmöglichen Druck betrieben. Dieser ist dadurch bestimmt, daß das Kopfprodukt der Niederdrucksäule - gegebenenfalls nach Durchgang durch einen oder mehrere Wärmetauscher - unter im wesentlichen Atmosphärendruck aus dem Verfahren entfernt werden kann; falls dieses Kopfprodukt als Regeneriergas in einer Reinigungseinrichtung (z.B. einer Molekularsiebanlage) eingesetzt wird, muß der Druck der Niederdrucksäule auch deren Betrieb ermöglichen.The low pressure column is preferably under the lowest possible pressure operated. This is determined by the fact that the top product of the low pressure column - if necessary after passing through one or more heat exchangers - under im substantial atmospheric pressure can be removed from the process; if this top product as regeneration gas in a cleaning device (e.g. one Molecular sieve system) is used, the pressure of the low pressure column must also enable their operation.

Es ist ferner günstig, wenn ein Teil der ersten sauerstoffangereicherten Sumpffraktion aus der Hochdrucksäule in die Mitteldrucksäule eingeleitet wird. Damit wird ein Teil des Sumpfproduktes aus der Hochdrucksäule weiter vorzerlegt, und damit eine größere Menge von stickstoffangereicherter Fraktion am Kopf der Mitteldrucksäule gewonnen, die als Rücklaufflüssigkeit in der Niederdrucksäule zur Verfügung steht. Dies bewirkt eine weitere Verbesserung der Rektifikation in der Niederdrucksäule.It is also advantageous if part of the first oxygen-enriched bottom fraction is introduced from the high pressure column into the medium pressure column. It becomes a part of the bottom product from the high pressure column, and thus one larger amount of nitrogen-enriched fraction at the top of the medium pressure column won, which is available as return liquid in the low pressure column. This further improves rectification in the low pressure column.

Die Sumpffraktion aus der Hochdrucksäule wird vorzugsweise an einer Zwischenstelle in die Mitteldrucksäule eingeführt, das heißt an einer Stelle, die mindestens einen praktischen oder theoretischen Boden oberhalb des Sumpfes der Mitteldrucksäule und insbesondere mindestens einen praktischen oder theoretischen Boden oberhalb der Stelle der Einspeisung des zweiten Luftteils in die Mitteldrucksäule liegt.The bottom fraction from the high pressure column is preferably at an intermediate point introduced into the medium pressure column, that is at a point that has at least one practical or theoretical floor above the sump of the medium pressure column and in particular at least one practical or theoretical floor above the point where the second air part is fed into the medium pressure column.

Die Erfindung betrifft außerdem eine Vorrichtung zur Tieftemperaturzerlegung von Luft gemäß dem Patentanspruch 8.The invention also relates to a device for the low temperature decomposition of Air according to claim 8.

Mit dem Verfahren und der Vorrichtung gemäß der Erfindung kann auch reiner Stickstoff produziert werden, wenn am Kopf der Niederdrucksäule zusätzlich ein üblicher Reinstickstoffabschnitt angeordnet wird. Auch die Argongewinnung ist möglich, wenn der Niederdrucksäule auf bekannte Weise (siehe beispielsweise EP-B-377117) eine Argonrektifikation nachgeschaltet ist. Ebenso können weitere Edelgase in bekannter Weise erzeugt werden.With the method and the device according to the invention can also be pure Nitrogen will be produced if there is an additional one at the top of the low pressure column Ordinary pure nitrogen section is arranged. Argon production is also possible if the low pressure column in a known manner (see for example EP-B-377117) an argon rectification is connected downstream. Likewise, other noble gases are generated in a known manner.

Die Erfindung sowie weitere Einzelheiten der Erfindung werden im folgenden anhand eines in der Zeichnung dargestellten bevorzugten Ausführungsbeispiels näher erläutert.The invention and further details of the invention are described below of a preferred embodiment shown in the drawing explained.

Einsatzluft 1 wird in einem Hauptluftverdichter 2 auf einen ersten Druck verdichtet. Die verdichtete Einsatzluft 3 wird in einen ersten Teilstrom 101, einen zweiten Teilstrom 201 und einen dritten Teilstrom 301 aufgeteilt. In den Verdichtem 5 und 102 werden der erste Teilstrom auf einen zweiten Druck und der zweite Teilstrom auf einen zwischen dem ersten und dem zweiten Druck liegenden dritten Druck gebracht. Dabei werden der erste Teilstrom und der zweite Teilstrom zunächst gemeinsam (4) im Verdichter 5 auf den dritten Druck und anschließend der erste Teilstrom 101 alleine weiter im Verdichter 102 auf den zweiten Druck komprimiert. Alternativ dazu können der erste und der zweite Teilstrom auch unabhängig voneinander verdichtet werden.Feed air 1 is compressed in a main air compressor 2 to a first pressure. The compressed feed air 3 is in a first partial flow 101, a second partial flow 201 and a third partial stream 301 divided. In the compressors 5 and 102 the first partial flow to a second pressure and the second partial flow to one brought between the first and the second pressure third pressure. there the first partial flow and the second partial flow are initially together (4) in Compressor 5 to the third pressure and then the first partial flow 101 alone further compressed in the compressor 102 to the second pressure. Alternatively, you can the first and the second partial stream can also be compressed independently of one another.

Wenn der Kältebedarf der Anlage und/oder die Produktreinheit relativ hoch sind, kann abweichend von der Darstellung in der Zeichnung der dritte Teilstrom, der der Entspannungsmaschine 305 beziehungsweise dem Nachverdichter 302 zugeführt wird, stromabwärts eines der Verdichter 5 oder 102 abgezweigt werden. Durch den damit erreichten höheren Eintrittsdruck beim Entspannen kann die Kälteleistung erhöht und/oder die Menge der direkt in die Niederdrucksäule eingeblasenen Luft verringert werden. If the cooling requirement of the system and / or the product purity are relatively high, can deviating from the representation in the drawing, the third partial stream, the Relaxation machine 305 or the post-compressor 302 fed will be branched downstream of one of the compressors 5 or 102. By the The cooling capacity achieved with this can increase the pressure when relaxing increased and / or the amount of air blown directly into the low pressure column be reduced.

Der unter dem zweiten Druck stehende erste Teilstrom 103 und der unter dem dritten Druck stehende zweite Teilstrom 201 werden in einem Hauptwärmetauscher 6 gegen Produktströme abgekühlt und in die Hochdrucksäule 7 beziehungsweise in die Mitteldrucksäule 8 eingespeist (104 bzw. 202). Die Hochdrucksäule 7 wird unter einem Druck von 4,5 bis 5,5 bar, vorzugsweise 4,6 bis 4,8 bar betrieben, die Mitteldrucksäule 8 steht unter 2,5 bis 3,5 bar, vorzugsweise 2,8 bis 3,0 bar.The first partial flow 103 under the second pressure and that under the third Second partial flow 201 under pressure is counteracted in a main heat exchanger 6 Product streams cooled and in the high pressure column 7 or in the Medium pressure column 8 fed (104 or 202). The high pressure column 7 is under operated at a pressure of 4.5 to 5.5 bar, preferably 4.6 to 4.8 bar Medium pressure column 8 is under 2.5 to 3.5 bar, preferably 2.8 to 3.0 bar.

Der erste Druck (in Leitung 3 hinter dem Hauptluftverdichter 2) ist deutlich niedriger als der Hochdrucksäulendruck; die Differenz beträgt mindestens 2,5 bar, vorzugsweise 3,0 bis 3,2 bar. Der zweite Druck liegt geringfügig über dem Hochdrucksäulendruck (beispielsweise etwa 0,1 bar über dem Druck an der Einspeisestelle in die Hochdrucksäule), um den Druckabfall im Hauptwärmetauscher 6 und in den Leitungen 103 und 104 auszugleichen. Analog dazu liegt der dritte Druck (stromabwärts des Verdichters 5) etwas oberhalb des Drucks der Mitteldrucksäule, um die Einführung des zweiten Teilstroms 201, 202 in die Mitteldrucksäule 8 zu gewährleisten.The first pressure (in line 3 behind the main air compressor 2) is significantly lower as the high pressure column pressure; the difference is at least 2.5 bar, preferably 3.0 to 3.2 bar. The second pressure is slightly above that High pressure column pressure (for example about 0.1 bar above the pressure at the Feeding point in the high pressure column) to the pressure drop in the main heat exchanger 6 and equalize in lines 103 and 104. The third pressure is analogous to this (downstream of the compressor 5) slightly above the pressure of the medium pressure column the introduction of the second partial flow 201, 202 into the medium pressure column 8 guarantee.

Der dritte Teilstrom 301 wird gegebenenfalls in einem Nachverdichter 302 auf einen vierten Druck nachverdichtet, der zwischen dem ersten Druck und dem Betriebsdruck der Mitteldrucksäule liegen kann und beispielsweise 1,5 bis 2,5 bar höher als der erste Druck ist. (Für den Fall, daß der dritte Teilstrom stromabwärts eines der Verdichter 5 oder 102 abgezweigt wird, ist der vierte Druck entsprechend höher, das heißt beispielsweise höher als der Druck der Mitteldrucksäule oder sogar höher als der Druck der Hochdrucksäule; er kann in diesem Fall bis zu 8 bar oder mehr betragen.) Über Leitung 303 geht es zum Hauptwärmetauscher 6 und von dessen kaltem Ende aus weiter (304) zur Entspannungsmaschine 305. Die arbeitsleistend entspannte Luft 306 wird auf mittlerer Höhe in die Niederdrucksäule 9 eingeleitet.The third partial flow 301 is optionally in a post-compressor 302 on a fourth pressure, which is between the first pressure and the operating pressure the medium pressure column can be, for example, 1.5 to 2.5 bar higher than that first print is. (In the event that the third partial flow downstream of one of the Compressor 5 or 102 is branched, the fourth pressure is correspondingly higher means for example higher than the pressure of the medium pressure column or even higher than the pressure of the high pressure column; in this case it can be up to 8 bar or more Via line 303 it goes to the main heat exchanger 6 and from it cold end from further (304) to the relaxation machine 305. The work-performing relaxed air 306 is introduced into the low-pressure column 9 at medium height.

Die Luft wird hinter jedem Verdichter 2, 5,102, 302 in indirektem Wärmeaustausch mit Kühlwasser abgekühlt, wie durch die in der Zeichnung dargestellten Nachkühler angedeutet ist. Bei mehrstufigen Verdichtern wird vorzugsweise zwischen zwei Stufen eine Zwischenkühlung durchgeführt.The air is behind each compressor 2, 5, 102, 302 in indirect heat exchange cooled with cooling water, as by the aftercoolers shown in the drawing is indicated. In the case of multi-stage compressors, there is preferably between two stages intercooling performed.

Bei der Rektifikation in der Hochdrucksäule 7 fallen eine erste stickstoffangereicherte Kopffraktion als Kopfgas und eine erste sauerstoffangereicherte Fraktion als Sumpfflüssigkeit an. Kopfgas 10 wird in einem ersten Kondensator-Verdampfer 11 kondensiert und zu einem Teil 12 in die Hochdrucksäule und zu einem anderen Teil 13 - gegebenenfalls nach Unterkühlung im Gegenströmer 14 - über Leitung 15 in die Niederdrucksäule 9 eingedrosselt (16), deren Betriebsdruck 1,1 bis 1,5 bar, vorzugsweise 1,2 bis 1,4 bar, liegt. Ein Teil der kondensierten stickstoffangereicherten Fraktion 13 aus der Hochdrucksäule kann über die optionale Leitung 17 zum Kopf der Mitteldrucksäule 8 geführt werden. Die Sumpfflüssigkeit der Hochdrucksäule wird über Leitung 18 ebenfalls nach optionaler Unterkühlung (14) in die Niederdrucksäule 9 entspannt (19, 20). Die Einspeisestelle liegt oberhalb derjenigen der arbeitsleistend entspannten Luft 306. Vorzugsweise wird ein Teil 37 (10 bis 30 %, vorzugsweise 15 bis 20 %) der Hochdrucksäulen-Sumpfflüssigkeit 18 in die Mitteldrucksäule geführt. Die Einspeisestelle liegt mindestens einen praktischen oder theoretischen Boden, vorzugsweise zwei bis fünf theoretische Böden oberhalb der Einspeisung des zweiten Luftteils 202.During the rectification in the high-pressure column 7, a first nitrogen-enriched precipitate Head fraction as head gas and a first oxygen-enriched fraction as Sump liquid. Top gas 10 is in a first condenser-evaporator 11 condensed and in part 12 in the high pressure column and in another part 13 - if necessary after subcooling in counterflow 14 - via line 15 in the Low pressure column 9 throttled (16), the operating pressure 1.1 to 1.5 bar, preferably 1.2 to 1.4 bar. Part of the condensed nitrogen enriched Fraction 13 from the high pressure column can via the optional line 17 to the top of the Medium pressure column 8 are performed. The bottom liquid of the high pressure column is over Line 18 also into the low pressure column 9 after optional subcooling (14) relaxed (19, 20). The feed point is above that of the work-performing relaxed air 306. Preferably, a portion 37 (10 to 30%, preferably 15 up to 20%) of the high-pressure column bottom liquid 18 into the medium-pressure column. The feed point is at least one practical or theoretical floor, preferably two to five theoretical plates above the feed of the second Air section 202.

In der Mitteldrucksäule 8 werden eine zweite stickstoffangereicherte Kopffraktion und eine zweite sauerstoffangereicherte Sumpfflüssigkeit gewonnen. Das Kopfgas 21 wird in einem zweiten Kondensator-Verdampfer 22 kondensiert und zu einem ersten Teil 23 in die Mitteldrucksäule und zu einem zweiten Teil 24 - gegebenenfalls nach Unterkühlung im Gegenströmer 14 - in die Niederdrucksäule 9 eingedrosselt (25). Die Sumpfflüssigkeit der Mitteldrucksäule wird über Leitung 26 ebenfalls nach optionaler Unterkühlung (14) in den Verdampfungsraum des zweiten Kondensator-Verdampfers 22 entspannt (27). Der verdampfte Strom 28 wird in die Niederdrucksäule 9 eingeführt (29). Die Einspeisestelle beispielsweise auf derselben Höhe wie diejenige der Sumpfflüssigkeit aus der Hochdrucksäule oder etwas darüber.In the medium pressure column 8, a second nitrogen-enriched head fraction and won a second oxygen-enriched sump liquid. The head gas 21 will condensed in a second condenser-evaporator 22 and to a first part 23 in the medium pressure column and to a second part 24 - if necessary after Hypothermia in counterflow 14 - throttled into low-pressure column 9 (25). The Bottom liquid of the medium pressure column is also optional via line 26 Hypothermia (14) in the evaporation space of the second condenser-evaporator 22 relaxed (27). The vaporized stream 28 is introduced into the low pressure column 9 (29). The feed point, for example, at the same level as that of the Bottom liquid from the high pressure column or something above it.

Dampf 31 für die Rektifikation in der Niederdrucksäule 9 wird durch Verdampfen von Sumpfflüssigkeit 30 im ersten Kondensator-Verdampfer 11 erzeugt. Der Kondensator-Verdampfer 11 kann abweichend von der Darstellung im Sumpf der Niederdrucksäule 9 angeordnet sein. Als Kopfprodukt verläßt Stickstoff 32 die Niederdrucksäule 9, wird in den Wärmetauschem 14 und 6 auf etwa Umgebungstemperatur angewärmt und bei 33 abgezogen. Gasförmiger Produktsauerstoff 35 wird über Leitung 34 entnommen und ebenfalls im Hauptwärmetauscher 6 erwärmt. Das Sauerstoffprodukt oder ein Teil davon kann bei Bedarf flüssig entnommen werden (Leitung 36). Für die Erzeugung eines Hochdruckprodukts kann der flüssig entnommene Sauerstoff auf Druck gebracht und verdampft werden (Innenverdichtung).Steam 31 for rectification in the low pressure column 9 is evaporated by Bottom liquid 30 generated in the first condenser-evaporator 11. The condenser evaporator 11 can deviate from the representation in the sump of the low pressure column 9 be arranged. Nitrogen 32 leaves the low-pressure column 9 as the top product warmed to about ambient temperature in the heat exchangers 14 and 6 subtracted at 33. Gaseous product oxygen 35 is sent via line 34 removed and also heated in the main heat exchanger 6. The oxygen product or a part of it can be removed liquid if required (line 36). For the Generation of a high pressure product can take up the liquid oxygen removed Pressure and evaporated (internal compression).

Die Reinigung der Einsatzluft ist in der Zeichnung nicht dargestellt. Sie kann durch jede der bekannten Methoden erfolgen, beispielsweise in einem umschaltbaren Wärmetauscher (Revex) oder in einer oder mehreren Molekularsiebanlagen. Im letzteren Fall ist es möglich, die gesamte Einsatzluft (Leitung 3) gemeinsam der Reinigung zu unterwerfen, die drei Teilströme 103, 201, 303 in getrennten Anlagen zu behandeln oder auch den ersten und zweiten Teilstrom gemeinsam durch ein unmittelbar stromabwärts des Nachkühlers des Verdichters 5 angeordnetes Molekularsieb zu schicken. Für den Fall, daß abweichend von der Darstellung in der Zeichnung der dritte Teilstrom hinter einem der Verdichter 5 oder 102 abgenommen und dem Nachverdichter 302 zugeleitet wird, können aller drei Teilströme oder zumindest der erste und der dritte Teilstrom gemeinsam gereinigt werden.The cleaning of the feed air is not shown in the drawing. You can by each of the known methods take place, for example in a switchable Heat exchanger (Revex) or in one or more molecular sieve systems. in the the latter case, it is possible to collectively use the entire feed air (line 3) Subject to cleaning, the three substreams 103, 201, 303 in separate systems treat or the first and second partial stream together through one arranged immediately downstream of the aftercooler of the compressor 5 Molecular sieve. In the event that different from the representation in the Drawing of the third partial flow behind one of the compressors 5 or 102 removed and is fed to the post-compressor 302, all three partial flows or at least the first and the third partial stream are cleaned together.

In dem Ausführungsbeispiel werden die Stoffaustauschelemente in der Hochdrucksäule und in der Mitteldrucksäule durch Destillierböden gebildet, diejenigen in der Niederdrucksäule durch geordnete Packung. Grundsätzlich können jedoch bei der Erfindung in jeder der Säulen konventionelle Destillierböden, Füllkörper (ungeordnete Packung) und/oder geordnete Packung eingesetzt werden. Auch Kombinationen verschiedenartiger Elemente in einer Säule sind möglich. Wegen des geringen Druckverlusts werden geordnete Packungen in allen Säulen, insbesondere in der Niederdrucksäule, bevorzugt. Diese verstärken die energiesparende Wirkung der Erfindung weiter.In the exemplary embodiment, the mass transfer elements in the High pressure column and those formed in the medium pressure column by still bottoms in the low pressure column by orderly packing. Basically, however, at of the invention in each of the columns conventional still bottoms (disordered packing) and / or ordered packing. Also Combinations of different elements in one column are possible. Because of the low pressure drop, ordered packings in all columns, in particular in the low pressure column, preferred. These increase the energy-saving effect the invention further.

Die untenstehenden Tabellen zeigen zwei Zahlenbeispiele für den in der Zeichnung dargestellten Prozeß, Tabelle 1 für die Gewinnung von reinem Sauerstoff (99,5 %) und Tabelle 2 für die Gewinnung von Sauerstoff mittlerer Reinheit (95,0 %). GOX-Reinheit: 99,5% Gesamtleistungsaufnahme der Verdichter: 13030 kW Zeichn. Menge Druck Temperatur Dampfanteil Anteil N2 Anteil Ar Anteil O2 [mol/s] [bar] [K] x<=1,0 [mol-%] [mol-%] [mol-%] 1 2985,0 1,00 295,0 1,0 78,12 0,93 20,95 301 520,0 1,63 298,0 1,0 78,12 0,93 20,95 4 2465,0 1,63 298,0 1,0 78,12 0,93 20,95 303 520,0 1,74 298,0 1,0 78,12 0,93 20,95 304 520,0 1,64 98,1 1,0 78,12 0,93 20,95 306 520,0 1,21 90,9 1,0 78,12 0,93 20,95 101 2110,8 3,12 298,0 1,0 78,12 0,93 20,95 201 354,2 3,12 298,0 1,0 78,12 0,93 20,95 103 2110,8 4,84 298,0 1,0 78,12 0,93 20,95 104 2110,8 4,74 101,2 1,0 78,12 0,93 20,95 202 354,2 3,02 97,8 1,0 78,12 0,93 20,95 34 620,0 1,22 92,0 1,0 0,00 0,50 99,50 35 620,0 1,12 297,9 1,0 0,00 0,50 99,50 36 5,0 1,22 92,0 0,0 0,00 0,32 99,68 28 342,1 1,22 86,6 1,0 55,44 1,44 43,12 24 197,8 2,90 87,6 0,0 99,33 0,46 0,21 vor 25 197,8 2,90 87,6 0,0 99,33 0,46 0,21 26 342,1 3,02 92,2 0,0 55,44 1,44 43,12 vor 27 342,1 3,02 92,2 0,0 55,44 1,44 43,12 13 1063,1 4,63 93,0 0,0 99,46 0,45 0,09 17 10,7 4,53 89,2 0,0 99,46 0,45 0,09 15 1052,4 4,53 89,2 0,0 99,46 0,45 0,09 18 1047,7 4,74 97,8 0,0 56,46 1,42 42,12 37 175,0 4,64 81,1 0,0 56,46 1,42 42,12 19 872,7 4,64 81,1 0,0 56,46 1,42 42,12 32 2360,0 1,20 79,0 1,0 98,81 1,05 0,14 33 2360,0 1,00 297,8 1,0 98,81 1,05 0,14 GOX-Reinheit: 95,0% Gesamtleistungsaufnahme der Verdichter: 10018 kW Zeichn. Menge Druck Temperatur Dampfanteil Anteil N2 Anteil Ar Anteil O2 [mol/s] [bar] [K] x<=1,0 [mol-%] [mol-%] [mol-%] 1 2850,0 1,00 295,0 1,0 78,12 0,93 20,95 301 953,2 1,49 298,0 1,0 78,12 0,93 20,95 4 1896,8 1,49 298,0 1,0 78,12 0,93 20,95 303 953,2 1,55 298,0 1,0 78,12 0,93 20,95 304 953,2 1,45 97,9 1,0 78,12 0,93 20,95 306 953,2 1,21 93,5 1,0 78,12 0,93 20,95 101 1294,6 3,11 298,0 1,0 78,12 0,93 20,95 201 602,2 3,11 298,0 1,0 78,12 0,93 20,95 103 1294,6 4,74 298,0 1,0 78,12 0,93 20,95 104 1294,6 4,64 98,6 1,0 78,12 0,93 20,95 202 602,2 3,01 97,3 1,0 78,12 0,93 20,95 34 620,0 1,22 91,8 1,0 2,55 2,45 95,00 35 620,0 1,12 297,9 1,0 2,55 2,45 95,00 36 5,0 1,22 91,8 0,0 0,67 1,62 97,71 28 575,6 1,22 86,6 1,0 55,64 1,44 42,92 24 320,9 2,89 87,6 0,0 99,18 0,46 0,36 vor 25 320,9 2,89 87,6 0,0 99,18 0,46 0,36 26 575,6 3,01 92,1 0,0 55,64 1,44 42,92 vor 27 575,6 3,01 92,1 0,0 55,64 1,44 42,92 13 652,0 4,52 92,8 0,0 99,24 0,46 0,30 17 3,1 4,42 81,0 0,0 99,24 0,46 0,30 15 648,9 4,42 81,0 0,0 99,24 0,46 0,30 18 642,6 4,64 97,5 0,0 56,69 1,41 41,90 37 291,2 4,54 80,1 0,0 56,69 1,41 41,90 19 351,4 4,54 80,1 0,0 56,69 1,41 41,90 32 2225,0 1,20 79,0 1,0 99,35 0,51 0,14 33 2225,0 1,00 297,8 1,0 99,35 0,51 0,14 The tables below show two numerical examples for the process shown in the drawing, Table 1 for the production of pure oxygen (99.5%) and Table 2 for the production of medium purity oxygen (95.0%). GOX purity: 99.5% total power consumption of the compressors: 13030 kW Sign. quantity print temperature Proportion of steam Share N2 Ar share O2 share [mol / s] [bar] [K] x <= 1.0 [mol%] [mol%] [mol%] 1 2985.0 1.00 295.0 1.0 78.12 0.93 20.95 301 520.0 1.63 298.0 1.0 78.12 0.93 20.95 4th 2465.0 1.63 298.0 1.0 78.12 0.93 20.95 303 520.0 1.74 298.0 1.0 78.12 0.93 20.95 304 520.0 1.64 98.1 1.0 78.12 0.93 20.95 306 520.0 1.21 90.9 1.0 78.12 0.93 20.95 101 2110.8 3.12 298.0 1.0 78.12 0.93 20.95 201 354.2 3.12 298.0 1.0 78.12 0.93 20.95 103 2110.8 4.84 298.0 1.0 78.12 0.93 20.95 104 2110.8 4.74 101.2 1.0 78.12 0.93 20.95 202 354.2 3.02 97.8 1.0 78.12 0.93 20.95 34 620.0 1.22 92.0 1.0 0.00 0.50 99.50 35 620.0 1.12 297.9 1.0 0.00 0.50 99.50 36 5.0 1.22 92.0 0.0 0.00 0.32 99.68 28 342.1 1.22 86.6 1.0 55.44 1.44 43.12 24th 197.8 2.90 87.6 0.0 99.33 0.46 0.21 before 25 197.8 2.90 87.6 0.0 99.33 0.46 0.21 26 342.1 3.02 92.2 0.0 55.44 1.44 43.12 before 27 342.1 3.02 92.2 0.0 55.44 1.44 43.12 13 1063.1 4.63 93.0 0.0 99.46 0.45 0.09 17th 10.7 4.53 89.2 0.0 99.46 0.45 0.09 15 1052.4 4.53 89.2 0.0 99.46 0.45 0.09 18th 1047.7 4.74 97.8 0.0 56.46 1.42 42.12 37 175.0 4.64 81.1 0.0 56.46 1.42 42.12 19th 872.7 4.64 81.1 0.0 56.46 1.42 42.12 32 2360.0 1.20 79.0 1.0 98.81 1.05 0.14 33 2360.0 1.00 297.8 1.0 98.81 1.05 0.14 GOX purity: 95.0% total power consumption of the compressors: 10018 kW Sign. quantity print temperature Proportion of steam Share N2 Ar share O2 share [mol / s] [bar] [K] x <= 1.0 [mol%] [mol%] [mol%] 1 2850.0 1.00 295.0 1.0 78.12 0.93 20.95 301 953.2 1.49 298.0 1.0 78.12 0.93 20.95 4th 1896.8 1.49 298.0 1.0 78.12 0.93 20.95 303 953.2 1.55 298.0 1.0 78.12 0.93 20.95 304 953.2 1.45 97.9 1.0 78.12 0.93 20.95 306 953.2 1.21 93.5 1.0 78.12 0.93 20.95 101 1294.6 3.11 298.0 1.0 78.12 0.93 20.95 201 602.2 3.11 298.0 1.0 78.12 0.93 20.95 103 1294.6 4.74 298.0 1.0 78.12 0.93 20.95 104 1294.6 4.64 98.6 1.0 78.12 0.93 20.95 202 602.2 3.01 97.3 1.0 78.12 0.93 20.95 34 620.0 1.22 91.8 1.0 2.55 2.45 95.00 35 620.0 1.12 297.9 1.0 2.55 2.45 95.00 36 5.0 1.22 91.8 0.0 0.67 1.62 97.71 28 575.6 1.22 86.6 1.0 55.64 1.44 42.92 24th 320.9 2.89 87.6 0.0 99.18 0.46 0.36 before 25 320.9 2.89 87.6 0.0 99.18 0.46 0.36 26 575.6 3.01 92.1 0.0 55.64 1.44 42.92 before 27 575.6 3.01 92.1 0.0 55.64 1.44 42.92 13 652.0 4.52 92.8 0.0 99.24 0.46 0.30 17th 3.1 4.42 81.0 0.0 99.24 0.46 0.30 15 648.9 4.42 81.0 0.0 99.24 0.46 0.30 18th 642.6 4.64 97.5 0.0 56.69 1.41 41.90 37 291.2 4.54 80.1 0.0 56.69 1.41 41.90 19th 351.4 4.54 80.1 0.0 56.69 1.41 41.90 32 2225.0 1.20 79.0 1.0 99.35 0.51 0.14 33 2225.0 1.00 297.8 1.0 99.35 0.51 0.14

Claims (11)

  1. Process for the low-temperature fractionation of air in a triple column system, which comprises a high-pressure column (7), a medium-pressure column (8) and a low-pressure column (9), comprising the following steps:
    (a) compression (2) of charge air (1) to a first pressure
    (b) introduction of a first part (101, 103, 104) of the compressed charge air (3) into the high-pressure column (7), the first part of the charge air being compressed (5, 102) from the first pressure to a second pressure, which is at least equal to the operating pressure of the high-pressure column (7)
    (c) introduction of a second part (201, 202) of the compressed charge air (3) into the medium-pressure column (8)
    (d) work-performing expansion (305) of a third part (301, 303, 304) of the compressed charge air (3)
    (e) introduction of the charge air (306) which has undergone work-performing expansion into the low-pressure column (9)
    (f) introduction (19) of at least part of a first oxygen-enriched bottom fraction (18) from the high-pressure column (7) into the low-pressure column (9)
    (g) condensation (11) of a first nitrogen-enriched top fraction (10) from the high-pressure column (7) and introduction of condensate (13, 15) thus obtained into the low-pressure column (9) as reflux,
    (h) introduction (28) of at least a part of a second oxygen-enriched bottom fraction (26) from the medium-pressure column (8) into the low-pressure column (9)
    (i) condensation (22) of a second nitrogen-enriched top fraction (21) from the medium-pressure column (8) and introduction (25) of condensate (24) thus obtained into the low-pressure column (9) as reflux
    characterized in that
    (j) the first pressure is lower than the operating pressure of the medium-pressure column (8), and
    (k) the second part of the charge air is compressed (5) from the first pressure to a third pressure, which is at least equal to the operating pressure of the medium-pressure column (8) but is lower than the second pressure.
  2. Process according to Claim 1, characterized in that the third part (301) of the charge air is recompressed (302) upstream of the work-performing expansion (305).
  3. Process according to Claim 2, characterized in that energy which is obtained during the work-performing expansion (305) of the third part (304) of the air is used for the recompression (302) of the third part (301) of the air.
  4. Process according to one of Claims 1 to 3,
    characterized in that the operating pressure at the top of the high-pressure column is approximately 4.8 bar or less.
  5. Process according to one of Claims 1 to 4,
    characterized in that the low-pressure column (9) is operated under a pressure which is only slightly above atmospheric pressure but is sufficient to remove the top fraction (32, 33) of the low-pressure column (9) - if appropriate after it has passed through one or more heat exchangers (14, 6) - from the process under substantially atmospheric pressure and/or to be used as regeneration gas in a cleaning device.
  6. Process according to one of Claims 1 to 5,
    characterized in that a part (37) of the first oxygen-enriched bottom fraction (18) from the high-pressure column (7) is introduced into the medium-pressure column (8).
  7. Process according to Claim 6, characterized in that the part (37) of the first oxygen-enriched bottom fraction from the high-pressure column is introduced into the medium-pressure column (8) at an intermediate point.
  8. Apparatus for the low-temperature fractionation of air in a triple column system, which has a high-pressure column (7), a medium-pressure column (8) and a low-pressure column (9), having
    (a) a principal air compressor (2) for compressing charge air (1) to a first pressure, which is lower than the operating pressure of the medium column,
    (b) having a first partial stream line (101, 103, 104), which is connected to the outlet of the principal air compressor (2) and to the high-pressure column (7), the first partial stream line leading through means (5, 102) for compressing charge air from the first pressure to a second pressure, which is at least equal to the operating pressure of the high-pressure column (7),
    (c) having a second partial stream line (201, 202), which is connected to the outlet of the principal air compressor (2) and to the medium-pressure column (8),
    (d) having a third partial stream line (301, 303, 304, 306), which is connected to the outlet of the principal air compressor (2) and leads through an expansion machine (305) to the low-pressure column (9),
    (e) having means for the introduction (13, 15, 16; 24, 25) of liquid from the top of the high-pressure column (7) and from the top of the medium-pressure column (8) into the low-pressure column (9) and for the introduction (18, 19, 20; 26, 27, 28, 29) of bottom liquid from the high-pressure column (7) and from the medium-pressure column (8) into the low-pressure column (9),
    and having
    (f) means (5) for compressing charge air (4) from the first pressure to a third pressure, which is at least equal to the operating pressure of the medium-pressure column (8) but is lower than the second pressure, the inlet of which means is connected to the outlet of the principal air compressor (2) and the outlet of which means is connected to the second partial stream line (201, 202).
  9. Apparatus according to Claim 8, characterized by a recompressor (302), which is arranged in the third partial stream line (301, 303) upstream of the expansion machine (305).
  10. Apparatus according to Claim 9, characterized by means for transmitting mechanical energy from the expansion machine (305) to the recompressor (302).
  11. Apparatus according to one of claims 8 to 10,
    characterized by means (37) for introducing bottom liquid from the high-pressure column (7) into the medium-pressure column (8).
EP96116124A 1995-10-11 1996-10-09 Triple column air separation process Expired - Lifetime EP0768503B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19537913A DE19537913A1 (en) 1995-10-11 1995-10-11 Triple column process for the low temperature separation of air
DE19537913 1995-10-11

Publications (3)

Publication Number Publication Date
EP0768503A2 EP0768503A2 (en) 1997-04-16
EP0768503A3 EP0768503A3 (en) 1998-02-04
EP0768503B1 true EP0768503B1 (en) 2001-07-25

Family

ID=7774605

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96116124A Expired - Lifetime EP0768503B1 (en) 1995-10-11 1996-10-09 Triple column air separation process

Country Status (3)

Country Link
US (1) US5730004A (en)
EP (1) EP0768503B1 (en)
DE (2) DE19537913A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009023900A1 (en) 2009-06-04 2010-12-09 Linde Aktiengesellschaft Method for cryogenic separation of air with distillation column system for nitrogen-oxygen separation, involves producing oxygen-enriched fraction and nitrogen fraction in high pressure column, and supplying nitrogen to low pressure column

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5682764A (en) * 1996-10-25 1997-11-04 Air Products And Chemicals, Inc. Three column cryogenic cycle for the production of impure oxygen and pure nitrogen
US6205815B1 (en) 1997-04-11 2001-03-27 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Plant for separation of a gas mixture by distillation
FR2774752B1 (en) * 1998-02-06 2000-06-16 Air Liquide AIR DISTILLATION SYSTEM AND CORRESPONDING COLD BOX
FR2774753B1 (en) * 1998-02-06 2000-04-28 Air Liquide AIR DISTILLATION SYSTEM COMPRISING MULTIPLE CRYOGENIC DISTILLATION UNITS OF THE SAME TYPE
DE19933558C5 (en) * 1999-07-16 2010-04-15 Linde Ag Three-column process and apparatus for the cryogenic separation of air
DE10103968A1 (en) * 2001-01-30 2002-08-01 Linde Ag Three-pillar system for the low-temperature separation of air
DE10113790A1 (en) * 2001-03-21 2002-09-26 Linde Ag Three-column system for low-temperature air separation
US6397631B1 (en) 2001-06-12 2002-06-04 Air Products And Chemicals, Inc. Air separation process
US8826692B2 (en) * 2008-01-28 2014-09-09 Linde Aktiengesellschaft Method and device for low-temperature air separation
FR2946735B1 (en) * 2009-06-12 2012-07-13 Air Liquide APPARATUS AND METHOD FOR AIR SEPARATION BY CRYOGENIC DISTILLATION.
FR2953915B1 (en) * 2009-12-11 2011-12-02 Air Liquide METHOD AND APPARATUS FOR AIR SEPARATION BY CRYOGENIC DISTILLATION
US8978413B2 (en) * 2010-06-09 2015-03-17 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Rare gases recovery process for triple column oxygen plant

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2854508C2 (en) * 1978-12-16 1981-12-03 Linde Ag, 6200 Wiesbaden Method and device for the low-temperature decomposition of a gas mixture
DE2903089A1 (en) * 1979-01-26 1980-07-31 Linde Ag METHOD FOR OBTAINING OXYGEN FROM AIR
DE3817244A1 (en) * 1988-05-20 1989-11-23 Linde Ag METHOD FOR DEEP TEMPERATURE DISPOSAL OF AIR
DE3840506A1 (en) * 1988-12-01 1990-06-07 Linde Ag METHOD AND DEVICE FOR AIR DISASSEMBLY
US5069699A (en) * 1990-09-20 1991-12-03 Air Products And Chemicals, Inc. Triple distillation column nitrogen generator with plural reboiler/condensers
US5233838A (en) * 1992-06-01 1993-08-10 Praxair Technology, Inc. Auxiliary column cryogenic rectification system
GB9213776D0 (en) * 1992-06-29 1992-08-12 Boc Group Plc Air separation
US5471843A (en) * 1993-06-18 1995-12-05 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and installation for the production of oxygen and/or nitrogen under pressure at variable flow rate
US5341646A (en) * 1993-07-15 1994-08-30 Air Products And Chemicals, Inc. Triple column distillation system for oxygen and pressurized nitrogen production
GB9325648D0 (en) * 1993-12-15 1994-02-16 Boc Group Plc Air separation
US5386692A (en) * 1994-02-08 1995-02-07 Praxair Technology, Inc. Cryogenic rectification system with hybrid product boiler
GB9414938D0 (en) * 1994-07-25 1994-09-14 Boc Group Plc Air separation
GB9414939D0 (en) * 1994-07-25 1994-09-14 Boc Group Plc Air separation

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009023900A1 (en) 2009-06-04 2010-12-09 Linde Aktiengesellschaft Method for cryogenic separation of air with distillation column system for nitrogen-oxygen separation, involves producing oxygen-enriched fraction and nitrogen fraction in high pressure column, and supplying nitrogen to low pressure column

Also Published As

Publication number Publication date
EP0768503A3 (en) 1998-02-04
US5730004A (en) 1998-03-24
EP0768503A2 (en) 1997-04-16
DE19537913A1 (en) 1997-04-17
DE59607348D1 (en) 2001-08-30

Similar Documents

Publication Publication Date Title
EP1139046B1 (en) Process and device for producing high pressure oxygen product by cryogenic air separation
EP1067345B1 (en) Process and device for cryogenic air separation
EP1243882B1 (en) Production of argon using a triple pressure air separation system with an argon column
EP1284404A1 (en) Process and device for recovering a product under pressure by cryogenic air separation
EP1031804B1 (en) Air separation process with nitrogen recycling
DE69105601T2 (en) Air separation.
EP0093448A2 (en) Process and apparatus for obtaining gaseous oxygen at elevated pressure
EP1074805B1 (en) Process for producing oxygen under pressure and device therefor
DE19803437A1 (en) Oxygen and nitrogen extracted by low-temperature fractional distillation
EP0768503B1 (en) Triple column air separation process
DE19908451A1 (en) A low temperature air fractionating system uses a rectification unit comprising pressure and low pressure columns and a nitrogen fraction recycle to the system air feed inlet, to provide bulk nitrogen
EP0948730A1 (en) Method and device for producing compressed nitrogen
EP1146301A1 (en) Process and apparatus for the production of high pressure nitrogen from air separation
DE19609490A1 (en) Oxygen-production process with reduced energy requirement
DE19951521A1 (en) Recovering pressurized product by low temperature decomposition of air in rectification system comprises cold compressing heat carrier stream before introducing into mixing column
EP2551619A1 (en) Method and device for extracting pressurised oxygen and pressurised nitrogen by cryogenic decomposition of air
DE60015849T2 (en) Cryogenic distillation plant for air separation
WO2014102014A2 (en) Method and device for low-temperature air separation
DE19933558C5 (en) Three-column process and apparatus for the cryogenic separation of air
EP1209431B1 (en) Process and apparatus for the production of nitrogen and oxygen
DE19725821A1 (en) Air separation process
EP1750074A1 (en) Process and device for the cryogenic separation of air
EP1050728B1 (en) Single column process and device for cryogenic air separation
DE102010056569A1 (en) Method for recovery of pressurized nitrogen product in distilling column system, involves making secondary portion of vaporized/pseudo-vaporized nitrogen flow in indirect heat exchange with oxygen-enriched liquid of high pressure column
DE19543395A1 (en) Double column process and device for the low temperature separation of air

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE ES FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE ES FR GB IT

17P Request for examination filed

Effective date: 19980706

17Q First examination report despatched

Effective date: 20000426

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT

REF Corresponds to:

Ref document number: 59607348

Country of ref document: DE

Date of ref document: 20010830

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20011012

ET Fr: translation filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20020131

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20021008

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20021009

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20021011

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031009

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040501

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20031009

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040630

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20051009