DE102016002115A1 - Distillation column system and method for producing oxygen by cryogenic separation of air - Google Patents

Abstract

The distillation column system and process are used to produce oxygen by cryogenic separation of air. The distillation column system has a conventional double column (2,3,4) and an argon-oxygen column (26) connected like a classic crude argon column. Below the argon-oxygen column (26) an oxygen column (36) in a common container (20) is arranged, which is connected in parallel to a portion of the low-pressure column 4 of the double column.

Description

The invention relates to a distillation column system for the production of oxygen by cryogenic separation of air according to the preamble of patent claim 1.

The basics of cryogenic separation of air in general and the construction of two-column systems in particular are described in the monograph "Cryogenic Technology" of Hausen / Linde (2nd edition, 1985) and in an essay by Latimer in Chemical Engineering Progress (Vol. 63, No. 2, 1967, page 35) described. The heat exchange relationship between the high-pressure column and the low-pressure column of a double column is usually realized by a main condenser in which head gas of the high-pressure column is liquefied against vaporizing bottom liquid of the low-pressure column.

The distillation column system of the invention can basically be designed as a classic two-column system with high-pressure column and low-pressure column. In addition to the two separation columns for nitrogen-oxygen separation, it can have other devices for obtaining other air components, in particular noble gases, for example krypton-xenon recovery.

An "argon discharge column" here refers to a separation column for argon-oxygen separation, which does not serve to obtain a pure argon product but to discharge argon from the air to be separated into the high-pressure column and low-pressure column. Their circuit differs only slightly from that of a classical crude argon column, but it contains significantly less theoretical plates, namely less than 40, especially between 35 and 15. Like a crude argon column, the bottom region of an argon discharge column is connected to an intermediate point of the low pressure column and the argon discharge column is passed through cooled a head condenser, on the evaporation side relaxed bottom liquid is introduced from the high pressure column; an argon discharge column has no bottom evaporator.

The term "argon-oxygen column" here refers to an argon-oxygen separation column formed either from a crude argon column having up to 80 theoretical plates or from an argon discharge column which generally produces a less pure overhead product. An argon-oxygen column has no bottom evaporator but an argon-oxygen column top condenser.

The main condenser and the argon-oxygen column top condenser are formed in the invention as a condenser-evaporator. The term "condenser-evaporator" refers to a heat exchanger in which a first condensing fluid stream undergoes indirect heat exchange with a second evaporating fluid stream. Each condenser-evaporator has a liquefaction space and an evaporation space, which consist of liquefaction passages or evaporation passages. In the liquefaction space, the condensation (liquefaction) of a first fluid flow is performed, in the evaporation space the evaporation of a second fluid flow. Evaporation and liquefaction space are formed by groups of passages that are in heat exchange relationship with each other.

In this case, the main condenser - and also the argon-oxygen column overhead condenser - as a single or multi-storey bath evaporator, in particular as a cascade evaporator (for example, as in EP 1287302 B1 = US Pat. No. 6,748,763 B2 described), or be designed as a falling film evaporator. It can be formed by a single heat exchanger block or by a plurality of heat exchanger blocks, which are arranged in a common pressure vessel.

The distillation column system of an air separation plant is arranged in one or more cold boxes. A "cold box" is here understood to mean an insulating casing which comprises a heat-insulated interior completely with outer walls; in the interior are arranged to be isolated plant parts, for example, one or more separation columns and / or heat exchangers. The insulating effect can be effected by appropriate design of the outer walls and / or by the filling of the gap between system parts and outer walls with an insulating material. In the latter variant, a powdery material such as perlite is preferably used. Both the distillation column system for nitrogen-oxygen separation of a cryogenic air separation plant and the main heat exchanger and other cold plant parts must be enclosed by one or more cold boxes. The outer dimensions of the coldbox usually determine the transport dimensions of prefabricated systems.

A "main heat exchanger" serves to cool feed air in indirect heat exchange with recycle streams from the distillation column system. It may be formed from a single or multiple parallel and / or serially connected heat exchanger sections, for example one or more plate heat exchanger blocks. Separate heat exchangers which specifically serve to vaporize or pseudo-evaporate a single liquid or supercritical fluid without heating and / or vaporization of another fluid, do not belong to the main heat exchanger.

The relative spatial terms "top", "bottom", "above", "below", "above", "below", "next to each other", "vertically", "horizontally" etc. refer here to the spatial orientation of the separation columns in normal operation. An arrangement of two columns or parts of apparatus "one above the other" is understood here to mean that the upper end of the lower of the two apparatus parts is at a lower or the same geodetic height as the lower end of the upper of the two apparatus parts and the projections of the two apparatus parts into one overlap horizontal plane. In particular, the two parts of the apparatus are arranged exactly one above the other, that is, the axes of the two columns extend on the same vertical line.

A distillation column system of the type mentioned is out US 5235816 known. Such systems are prefabricated regularly as far as possible in the production, the prefabricated parts are transported to the site and finally connected there. Depending on the size of the system, for example, the entire double column can be transported with its coldbox. If the size of the plant no longer allows this, the double column - in one piece or possibly in two or more parts - transported without coldbox. An additional column such as the argon-oxygen column causes additional effort with its own cold box and supporting steel structure. It has to be brought to the construction site separately on a regular basis and connected there with the rest of the plant with relatively great effort on site. For many plants that need to be transported over long distances by land, maximum transport heights that limit the diameter of the columns apply. In order to realize larger oxygen capacities with limited diameter, one generally uses less and less dense packing. As a result, the separation columns are getting longer or higher.

The invention has for its object to make a distillation column system of the type mentioned as compact as possible and in particular to reduce its height while maintaining capacity, especially for very large air separation plants for an air volume of more than 300,000 Nm ³ / h, preferably more than 360,000 Nm ³ / h.

This object is solved by the features of patent claim 1.

The argon-oxygen column is extended downwards by a further mass transfer area, which is used as an oxygen column. This can - like the other sections in high-pressure column, low-pressure column and argon-oxygen column - by conventional rectification soils such as sieve trays, random packing (disordered packing) or ordered (structured) pack are formed. Preferably, ordered packing is used in the low-pressure column and in the argon-oxygen column.

In order to effect a mass transfer, an ascending gas must be introduced below the further mass transfer area. This is done by "means for introducing an oxygen-rich gas" in the bottom of the column of oxygen. The "oxygen-rich gas" can either be introduced from the outside into the oxygen column or originate from a bottom evaporator arranged in the bottom of the oxygen column. When introduced from the outside, the "oxygen-rich gas" is withdrawn at any point of the low-pressure column below the gas outlet, which serves to feed gas into the argon-oxygen column and introduced into the container below the gas feed to the argon-oxygen column. This stream thus has a higher oxygen content than the gas outlet into the argon-oxygen column. This oxygen content is at least 80%, preferably more than 90%, in particular more than 97%. Ideally, this oxygen content corresponds to the concentration of the oxygen-rich gas in the bottom of the low-pressure column and is drawn off above the main condenser. The return, which arrives at the bottom of the column of oxygen, is fed back to the low-pressure column, ideally at the same point where the gas for feeding into the column of oxygen is withdrawn from the low-pressure column. Alternatively, a bottom evaporator can be installed in the bottom of the oxygen column. Basically, you can make the capacity equalization between the oxygen column and the low pressure column with liquid instead of gas from the low pressure column, then gas would flow from the oxygen column back into the low pressure column.

In the invention, the container of the argon-oxygen column is not only used as usual for argon enrichment of the argon-oxygen mixture from the low-pressure column, but also for depletion of the down-flowing liquid to argon and thus for the accumulation of oxygen. The lower part of the container, the oxygen column, thus acts much like a corresponding part of the oxygen portion of the low-pressure column and is connected to this practically in parallel. Thus, the corresponding part of the oxygen section is relieved, since there flow less gas and liquid during operation of the system. For example, the ratio between the gas quantity rising there and in the oxygen column is from 20:80 to 50:50.

The relevant part of the oxygen section can therefore be equipped with a reduced capacity, for example by use a denser pack. However, this increases the effectiveness of the section and the section can be built lower. In this way, the overall height of the low-pressure column or the entire double column is reduced. Prefabrication, transport and construction of the double column require correspondingly less effort.

The oxygen column is preferably formed so that the oxygen concentration in its sump is equal to that in the bottom of the low-pressure column. The "part of the oxygen section" described above is formed by the entire oxygen section between the bottom of the low-pressure column and the gas line to the argon-oxygen column.

In a first variant of the invention, the means for introducing an oxygen-rich gas through an oxygen gas line for the introduction of oxygen-rich gas from the low-pressure column are formed in the bottom region of the oxygen column. In principle, the oxygen column can also have a bottom evaporator in this variant; In general, however, it is carried out in the first variant without sump heating. The load distribution can be shifted via an additional liquid line, which is preferably drawn off at the same point of the low-pressure column as the gas line. In this case, one would return gas from the oxygen column in the low-pressure column in order not to unnecessarily burden the argon-oxygen column.

In a second variant, the oxygen column has an oxygen column bottom heating, which is designed as a condenser-evaporator, wherein the evaporation space of the oxygen column bottom heating is in particular in flow connection with the bottom region of the oxygen column. Ideally, the oxygen column bottom heater is arranged so that the bottoms liquid of the oxygen column can flow into the low pressure column by virtue of the hydrostatic pressure gradient.

In the second variant, the distillation column system may further comprise a second high-pressure column which is disposed below the container of the argon-oxygen column and whose head portion is in fluid communication with the liquefaction space of the oxygen column sump heater; in the oxygen column bottom heating, top gas of the second high-pressure column is thus liquefied. The combination of argon-oxygen column and oxygen column (top) and second high-pressure column (bottom) thus form a kind of double column with the oxygen column bottom heater as a "main capacitor".

In this way, not only the oxygen portion of the low-pressure column, but also a part of the first high-pressure column or the entire first high pressure column can be relieved in the manner described above and thus built lower. The capacity distribution between the first and second high-pressure column is for example about 60 to 40. In individual cases, one could split the load between the two parallel systems so that a high-pressure column at the head produces the gaseous pressure nitrogen product and the other, parallel high-pressure column produces no gaseous pressure nitrogen product. This can be saved in the latter high-pressure column section for pressurized nitrogen production.

In principle, the second high pressure column of the complete first high pressure column can be connected in parallel. In many cases, however, it is more favorable if the bottom region of the second high-pressure column is connected via a nitrogen gas feed line and a liquid nitrogen return line to an intermediate point of the first high-pressure column. Thus, the discharge acts specifically for the area of the first high-pressure column above the connection with the nitrogen gas supply line. Nitrogen gas is introduced from an intermediate point of the first high-pressure column into the second high-pressure column, and liquid nitrogen from the bottom of the second high-pressure column is returned to the intermediate point of the first high-pressure column.

• – ein Teil der Sumpfflüssigkeit der ersten Hochdrucksäule,
• – ein Teil einer flüssigen Einsatzluftfraktion beziehungsweise einer entsprechenden aus der ersten Hochdrucksäule entnommenen Fraktion,
• – ein Teil einer flüssigen Stickstofffraktion von einer Zwischenstelle der ersten Hochdrucksäule,
• – ein Teil eines arbeitsleistend entspannten Luftstroms.

The argon-oxygen column overhead condenser may be arranged in the bottom of a side column, and one, several or all of the following liquid fractions may be introduced into the side column:

• A part of the bottom liquid of the first high-pressure column,
• A part of a liquid feed air fraction or of a corresponding fraction taken from the first high-pressure column,
• A part of a liquid nitrogen fraction from an intermediate point of the first high-pressure column,
• - Part of a work-relaxing air flow.

In addition, the argon-oxygen column can be formed through an argon discharge column and the argon-oxygen column top condenser through an argon discharge column top condenser.

The invention and further details of the invention are explained below with reference to embodiments schematically illustrated in the drawings. Hereby show:

1 an embodiment of the first variant of the distillation column system according to the invention without bottom heating of the oxygen column,

2 a first embodiment of the second variant with oxygen column sump heating and a short second high-pressure column,

3 A second embodiment of the second variant with a longer second high-pressure column,

4 A third embodiment of the second variant with even longer second high-pressure column,

5 a fourth embodiment of the second variant, which 2 and additionally having a mass transfer region above the argon discharge column head condenser, and

6 a fifth embodiment of the second variant, in which the uppermost portion of the second high-pressure column is saved.

In all embodiments, the warm part of the air separation plant and the main heat exchanger are executed in a usual way and therefore not shown in the drawings. In all embodiments, the argon-oxygen column is formed by an argon discharge column and the argon-oxygen column top condenser through an argon discharge column top condenser. However, the embodiments are basically also suitable for the case that the argon-oxygen column is formed by a crude argon column, that is, has more theoretical plates than an argon discharge column.

In the embodiment of the 1 becomes a first feed air stream 1 , which was purified of water and carbon dioxide and cooled to about dew point, under a pressure of, for example, 5.5 bara gaseous in a first high-pressure column 2 initiated. The first high pressure column 2 forms together with the main capacitor 3 and the low pressure column 4 a double column, that is, the three apparatuses are arranged one above the other, as shown in the drawing. A second feed air stream 5 becomes liquid in the first high-pressure column 2 initiated; a part 6 of it is immediately taken again, in a subcooling countercurrent 7 cooled and over line 7 in the low pressure column 4 fed.

The gaseous head nitrogen 8th the first high-pressure column becomes a part 9 into the liquefaction space of the main condenser 3 initiated. Generated liquid nitrogen 10 becomes a first part 11 in the subcooling countercurrent 7 cooled and recovered as liquid nitrogen product LIN. The rest 12 is used as reflux to the top of the first high-pressure column 2 given up. Via wire 13 may be another part of the gaseous head nitrogen 8th the first high-pressure column 2 be obtained as a gaseous pressure product. Impure liquid nitrogen 14 is from an intermediate point of the first high-pressure column 2 deducted, in the subcooling countercurrent 7 cooled and over line 15 on the head of the low-pressure column 4 given up.

From the low pressure column 4 is withdrawn as the main product of the plant oxygen, as liquid oxygen 16 from the bottom of the low pressure column 4 (or from the evaporation space of the main capacitor 3 ). The liquid oxygen is via line 17 fed to an internal compression. It is brought to an elevated pressure in the liquid state, evaporated or pseudo-evaporated under this increased pressure in the main heat exchanger (if the increased pressure is supercritical) and finally delivered as gaseous pressure product (these process steps and the corresponding parts of the apparatus are not shown here).

Another liquid oxygen fraction 41 is above the main capacitor 3 deducted, optionally in the subcooling countercurrent 7 cooled and finally recovered as liquid oxygen product LOX. At the top of the low-pressure column 4 becomes gaseous impurity nitrogen 18 removed as residual gas and through the subcooling countercurrent 7 and via wire 19 led to the cold end of the main heat exchanger.

An argon discharge column 26 is in a container 20 arranged. Further down in the same container 20 there is an oxygen column 36 , The tank, the argon discharge column 26 and the oxygen column 36 are through a gas pipe 21 and a liquid line 22 with an intermediate point of the low-pressure column 4 connected. With the two lines you can see the capacity in the oxygen column 36 to adjust. Is the fluid line 22 closed (or missing), the capacity between the two columns is distributed so that the sales in the output (the oxygen column 36 ) corresponds to the turnover of the lift (the argon discharge column). Should more capacity in the output of the container 20 (the oxygen column 36 ) is moved over the liquid line 22 - contrary to in 1 drawn flow direction - liquid from the low pressure column 4 into the oxygen column 36 transported. This additional capacity is taken as the corresponding amount of gas of the oxygen column below the Argonausschleussäule and fed to the low pressure column. (Within the scope of the invention may gas line 21 and fluid line 22 also be combined in a single line with a particularly large cross-section.)

The argon discharge column has an argon discharge column head condenser 23 on, the liquefaction room on the lines 24 (Gas) and 25 (liquid) is in flow communication with the head of the argon discharge column. The argon discharge column head condenser 23 can - as shown - be realized as a bath evaporator. Instead of the single-stage evaporator, a multi-storey condenser-evaporator can be used, for example, a cascade condenser according to EP 1287302 B1 = US Pat. No. 6,748,763 B2 , On the liquefaction side, it can be designed as a reflux condenser.

Via cables 28 . 29 . 30 and the subcooling countercurrent 7 is the evaporation space of the argon discharge column head capacitor 23 with the bottom of the first high pressure column in fluid communication. In operation of the distillation column system is via these lines 28 . 29 . 30 liquid crude oxygen from the bottom of the first high-pressure column 2 introduced. This partially vaporizes and then passes through a gas line 31 or a liquid line 32 in the low pressure column 4 introduced. The part 33 of the raw liquid oxygen which is not introduced into the argon discharge column head condenser flows directly into the low pressure column 4 , Alternatively, the whole lot 29 over the capacitor 23 be guided.

About the gas line 21 (and / or from the oxygen column 36 ), a mixture flows into the argon discharge column 26 which contains about 10 mol% of argon and, moreover, mainly consists of oxygen. In the argon discharge column 26 Argon is enriched. Via wire 27 a residual gas leaves the argon discharge column 26 or the argon discharge column head capacitor 23 containing about 75 mol% of argon. management 27 leads in turn to the cold end of the main heat exchanger, not shown.

In that regard, the Argonausschleussäule corresponds 26 a conventional Argonausschleussäule. According to the invention is in its container 20 in addition the oxygen column 36 installed in the container 20 below the gas line 21 and thus below the Argonausschleussäule 26 is arranged. In addition, the oxygen column indicates 36 in her swamp area means 35 for introducing an oxygen-rich gas.

Inside the oxygen column 36 the downflowing liquid is depleted of argon. The bottoms liquid 34 the oxygen column 36 has about the same composition as the bottom liquid 16 the low pressure column 4 and is mixed with this. Alternatively, the bottoms liquid 34 wholly or partly in the line 41 fed and recovered as a liquid product LOX (not shown in the drawing).

In the opposite direction becomes gaseous oxygen 35 from the bottom region of the low-pressure column 4 or from the evaporation space of the main capacitor 3 in the bottom area of the oxygen column 36 20 initiated and serves as ascending gas.

In one of the lowest packing sections 37 . 38 the low pressure column 4 and the argon discharge column 20 or both will be down one or more layers of copper packing 40 . 39 used. By "copper" is meant here pure copper or an alloy having a copper content of at least 67%, preferably at least 80%, most preferably at least 90% (in each case based on the mass). In particular, the term "copper" includes all materials specified in Annex C of the EIGA document IGC Doc 13/02 / E as "copper" and "copper-nickel alloys"("Copper" / "Copper-Nickel Alloys" in EIGA - OXYGEN PIPELINE SYSTEMS - IGC Doc 13/02 / E issued 10 by the European Industrial Gases Association).

The remaining packing layers of the lowest packing sections 37 . 38 the low pressure column are formed by a conventional ordered aluminum package. The details of using a copper packing in the low pressure column are in EP 2645031 A1 described.

In the embodiment, 60% flow in the main capacitor 3 generated gaseous oxygen as an ascending gas in the bottom mass transfer section 37 the low pressure column 4 , The remaining 40% go via wire 35 into the oxygen column 36 and form in there lowest mass transfer section 38 the rising steam. This will be the oxygen section of the low pressure column 4 (up to the gas supply 21 ) relieved by 40%. Accordingly, a particularly dense packing can be used there and thus height can be saved. Preferably, when laying out the system, the load between the two columns is distributed so that the lowest possible column heights for both columns.

• – eine Sauerstoffsäulen-Sumpfheizung 203 und
• – eine zweite Hochdrucksäule 202

2 differs from 1 by

• - an oxygen column sump heater 203 and
• - a second high pressure column 202

In the liquefaction room of the oxygen column sump heater 203 becomes a part 209 of the head nitrogen 208 the second high pressure column 202 condensed; the rest 213 can be obtained as gaseous pressure product and optionally with top nitrogen 13 from the first high-pressure column 2 be mixed. The direct nitrogen product from the high pressure columns is then passed over a common conduit 113 led to the main heat exchanger. The one in the Oxygen column sump heater 203 recovered liquid nitrogen 210 becomes a first part 212 the first high-pressure column 2 and to a second part 211 the second high pressure column 202 abandoned as return.

As in 1 become the liquid oxygen fractions 16 . 34 from the swamps of the oxygen column 36 and the low pressure column 4 united (17). This can be done either through a common piping or that - diverging from the drawing - the bottom liquid of a column passed into the bottom of the other and from there the common product is withdrawn. The bottom of the second high-pressure column 202 is via a gas supply line 241 for impure gaseous nitrogen and a liquid return 242 for impure liquid nitrogen with an intermediate point of the first high-pressure column 2 connected.

In this embodiment, the main capacitor 3 and the uppermost portion of the first high pressure column 2 in addition to the oxygen section of the low pressure column 4 relieved by 40% of the first high-pressure column 2 ascending steam over the gas supply line 241 in the second high-pressure column 202 be directed. Correspondingly less gas condenses in the main condenser 3 ; the "missing" amount of liquid nitrogen is in the oxygen column sump heater 203 generated. Thus, the height of the main capacitor 3 and the top section (above the gas supply line 241 ) of the first high-pressure column 2 be reduced.

3 shows a modification of the embodiment of 2 , By means of an additional mass transfer section 350 in the second high pressure column 202 For example, the downflowing liquid may be further enriched in oxygen, for example to about 20 percent. Via a gas supply line 341 and a liquid return 342 is the bottom of the second high pressure column with a second intermediate point of the first high pressure column 2 connected, preferably with the point at which the liquid feed air 5 is fed. In this way, in addition, the section of the first high-pressure column 2 between the lines 242 and 341 relieved.

In 4 contains the second high-pressure column 202 across from 3 yet another mass transfer section 450 and thus can be completely parallel to the first high-pressure column 2 operate. The oxygen-enriched bottoms liquid 442 the second high pressure column 202 comes with the bottoms liquid 28 from the first high-pressure column united and together over the line 428 continued. Rising gas for the second high-pressure column 202 is through a part 401 of the first gaseous feed air stream 1 formed in the sump area of the second high-pressure column 202 is initiated. Here, the load of the complete first high pressure column can be optimized by introducing appropriate amounts into the second high pressure column and deducted from it. The height of the first high-pressure column can thus be further reduced.

5 shows a further modification of the embodiment of 2 , Here is a page column 504 to the low pressure column 4 used, wherein the argon discharge column head capacitor 23 as bottom evaporator of the side column 504 acts. If side column 504 , Container 20 with argon discharge column 26 and oxygen column 36 and second high pressure column 202 - as in 5 shown - are arranged one above the other, they result in a triple column. About a sump liquid line 32 becomes the in the argon discharge column head condenser 23 non-evaporated portion of the bottom liquid of the low-pressure column 4 fed, at an intermediate point, which lies above the intermediate point at which the low-pressure column 4 via a gas line 21 and a liquid line 22 for an argon enriched. Fraction with argon discharge column 26 connected is.

In addition, only a first part 30 the bottoms liquid 28 . 29 from the first high-pressure column 2 the side panel 504 into the evaporation space of the argon discharge column head condenser 23 directed. A second part 530 becomes the side column 504 forwarded to an intermediate body. A third part 33 is directly in the low pressure column 4 fed. Another liquid feed fraction for the side column 504 is through a part 507 the liquid feed air 7 (or the corresponding taken from the first high-pressure column fraction) formed. At the head of the side column 504 becomes impure nitrogen 518 obtained the same or a similar composition as the top product 18 the low pressure column 4 having. The two gaseous impure nitrogen streams 18 . 518 be together over line 519 led to warming up.

Alternatively, the two nitrogen streams 18 . 518 also be routed separately to and through the HWT, so that the low-pressure column and the side column can be driven with different head pressures.

Of course, the side column 504 of the 5 also with the embodiments of the 1 to 4 be combined.

For example, shows 6 a combination of the side column 504 of the 5 with a second High-pressure column 202 according to 4 ; deviating from 4 Here is the second high-pressure column 202 only at the swamp (pipe 442 ) and on the head (lines 211 and 213 ) with the first high-pressure column 2 connected. The second high pressure column 202 produces only impure nitrogen here 208 in liquid form 211 in the first high-pressure column 2 and / or in the low pressure column 4 can be used as return. This allows the second high-pressure column 202 significantly shorter and thus cheaper than in 4 be executed. A printed product directly from the head of the second high-pressure column 202 is not won here. With a change between the versions of the second high-pressure column after 4 and 6 the column size can be adapted flexibly to the existing boundary conditions.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1287302 B1 [0007, 0039]
• US Pat. No. 6,748,763 B2 [0007, 0039]
• US 5235816 [0011]
• EP 2645031 A1 [0046]

Cited non-patent literature

• Hausen / Linde (2nd Edition, 1985) [0002]
• Chemical Engineering Progress (Vol. 63, No. 2, 1967, page 35) [0002]

Claims (10)

Distillation column system for generating oxygen by cryogenic separation of air with - a first high-pressure column ( 2 ) and a low-pressure column ( 4 ), which are arranged one above the other, - a main capacitor ( 3 ), which is designed as a condenser-evaporator, wherein the liquefaction space of the main capacitor ( 3 ) with the head of the first high-pressure column ( 2 ) in fluid communication ( 16 . 9 . 10 . 12 ) and the evaporation space of the main capacitor ( 3 ) with the bottom of the low-pressure column ( 4 ) is in flow communication, - an argon-oxygen column ( 26 ) stored in a container ( 20 ) is arranged and in its lower region via a gas line ( 21 ) and / or a liquid line ( 22 ) with an intermediate point of the low-pressure column ( 4 ) and with an argon-oxygen column top condenser ( 23 ), which is designed as a condenser-evaporator, wherein the liquefaction space of the argon-oxygen-column top condenser ( 23 ) with the head of the argon-oxygen column ( 26 ) in fluid communication ( 24 . 25 ) and the evaporation space of the argon-oxygen-column overhead condenser ( 23 ) with the bottom of the first high-pressure column ( 2 ) in fluid communication ( 28 . 29 . 30 ), characterized in that - the container ( 20 ) of the argon-oxygen column ( 26 ) an oxygen column ( 36 ), which is located below the argon-oxygen column, and that - the oxygen column ( 36 ) in its swamp area ( 35 . 203 ) for introducing an oxygen-rich gas and means ( 34 ) for removing an oxygen-rich liquid. A distillation column system according to claim 1, characterized in that the means for introducing an oxygen-rich gas through an oxygen gas line ( 35 ) for the introduction of oxygen-rich gas from the low-pressure column ( 4 ) in the bottom region of the oxygen column ( 36 ) are formed. A distillation column system according to claim 1, characterized by an oxygen column bottom heater ( 203 ), which is designed as a condenser-evaporator, wherein the evaporation space of the oxygen column sump heater ( 203 ) in flow communication with the bottom region of the oxygen column ( 36 ) stands. A distillation column system according to claim 2, characterized by a second high-pressure column ( 202 ), which are below the container ( 20 ) of the argon-oxygen column ( 26 ) and whose head area is connected to the liquefaction space of the oxygen column bottom heating ( 203 ) in fluid communication ( 208 . 209 . 210 . 212 ) stands. Distillation column system according to one of claims 4, characterized in that the bottom region of the second high pressure column ( 202 ) via a nitrogen gas supply line ( 241 ) and a liquid nitrogen return line ( 242 ) with an intermediate point of the first high-pressure column ( 2 ) connected is. A distillation column system according to any one of claims 1 to 5, characterized by a side column ( 504 ) in whose sump the argon-oxygen-column overhead condenser ( 23 ) and having means for introducing one, several or all of the following liquid fractions: - a part ( 530 ) of the bottoms liquid ( 28 . 29 ) of the first high-pressure column ( 2 ), - a part ( 507 ) a liquid feed air fraction ( 5 ) or a corresponding one from the first high-pressure column ( 2 ) fraction ( 7 ), - a part ( 515 ) of a liquid nitrogen fraction ( 14 . 15 ) from an intermediate point of the first high-pressure column ( 2 ), - a part of a working air relaxed airflow. A distillation column system according to any one of claims 1 to 6, characterized in that the argon-oxygen column is formed by an argon discharge column and the argon-oxygen column top condenser is formed by an argon discharge column overhead condenser. Process for producing oxygen by cryogenic separation of air in a distillation column system, comprising - a first high-pressure column ( 2 ) and a low pressure column ( 4 ), which are arranged one above the other, and a main capacitor ( 3 ), which is designed as a condenser-evaporator, wherein the liquefaction space of the main capacitor ( 3 ) with the head of the first High pressure column ( 2 ) in fluid communication ( 16 . 9 . 10 . 12 ) and the evaporation space of the main capacitor ( 3 ) with the bottom of the low-pressure column ( 4 ) is in flow communication, - and also an argon-oxygen column ( 26 ) contained in a container ( 20 ) is arranged and in its lower region via a gas line ( 21 ) and / or a liquid line ( 22 ) with an intermediate point of the low-pressure column ( 4 ) and an argon-oxygen column overhead condenser ( 23 ), which is designed as a condenser-evaporator, wherein the liquefaction space of the argon-oxygen-column top condenser ( 23 ) with the head of the argon-oxygen column ( 20 ) in fluid communication ( 24 . 25 ) and the evaporation space of the argon-oxygen-column overhead condenser ( 23 ) with the bottom of the first high-pressure column ( 2 ) in fluid communication ( 28 . 29 . 30 ), wherein 1 ) in the first high-pressure column 2 is introduced and an oxygen product stream 17 from the low-pressure column ( 4 ), characterized in that - the container ( 20 ) of the argon-oxygen column ( 26 ) an oxygen column ( 36 ), which is located below the argon-oxygen column, and that - an oxygen-rich gas in the bottom region of the oxygen column ( 36 ) ( 35 . 203 ) and - an oxygen-rich liquid from the bottom region of the oxygen column ( 36 ) ( 34 ) becomes. A method according to claim 8, characterized in that an oxygen-rich gas from the low pressure column ( 3 ) in the bottom region of the oxygen column ( 36 ) ( 35 ) becomes. Process according to claim 8, characterized in that in an oxygen column bottom heating ( 203 ), which is designed as a condenser-evaporator, bottom liquid of the oxygen column ( 36 ) is evaporated.

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