Air separation device

Abstract

To provide an air separation device that is safe even in a high-concentration oxygen atmosphere, even when a regulated packing used in a bottom section of a low-pressure tower is made of aluminum, and which can reduce a tower height without increasing a tower diameter.SOLUTION: An air separation device 1 comprises a high-pressure tower 500, a low-pressure tower 600, and a main condenser 300. A bottom section of the low-pressure tower 600 is packed with a regulated packing 600a, the regulated packing 600a being a laminate of corrugated sheets made of aluminum. The corrugated sheets have a plate thickness of 0.2 mm or more, a specific surface area of 750 m2 / m3 or more, a wave inclination angle of 55° or more with respect to the horizontal, and a curvature circle diameter at a wave crest part that is 60% or more of a crest height.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an air separation device having a high-pressure column and a low-pressure column for separating and collecting nitrogen and oxygen from air by low-temperature distillation. More specifically, the present invention relates to an air separation device using a structured packing for efficiently bringing the descending liquid and the ascending gas in the column into gas-liquid contact.

Background Art

[0002] In order to separate and collect nitrogen and oxygen from air by low-temperature distillation, an air separation device is used. The air separation device mainly consists of two distillation columns called a high-pressure column and a low-pressure column. In this low-pressure column, the reflux liquid supplied into the column becomes the descending liquid, and oxygen, which is a high-boiling component, is concentrated while flowing down by gas-liquid contact with the ascending gas in the column. For example, liquid oxygen with a concentration of 99.5% or more is generated at the bottom of the column. Also, while the ascending gas rises, nitrogen, which is a low-boiling component, is concentrated, and nitrogen gas is generated at the top of the column.

[0003] In the low-pressure column, structured packing is used to efficiently bring the descending liquid and the ascending gas into gas-liquid contact. The structured packing is formed by standing a metal sheet (corrugated sheet) processed into a corrugated shape with a specific orientation (wave tilt angle) with respect to the column axis vertically with respect to the column cross-section, and laminating a plurality of sheets so that the inclination directions of the waveforms of the metal sheets intersect, and forming a cylindrical or block shape.

[0004] The reflux liquid flows down along the corrugated portion of the metal sheet, and the ascending gas rises through the flow path formed from the wave crests between the sheets. From such gas-liquid flow, when the specific surface area (surface area per unit volume) of the structured packing is increased, the area where gas-liquid contacts becomes larger, the separation performance is improved, and the column height can be reduced. On the other hand, since the space through which the gas can pass becomes smaller, the column diameter has to be increased so as not to entrain the reflux liquid. Also, when the wave tilt angle is made smaller with respect to the horizontal, the gas-liquid contact resistance increases and the separation performance is enhanced, and the column height can be reduced. On the other hand, the column diameter becomes larger in order to suppress an increase in pressure loss.

[0005] The structured packings generally used in the low-pressure column are made of aluminum. However, at the bottom of the column where the oxygen concentration is high, for safety reasons to avoid the risk of oxygen ignition and combustion of the packings, a plate thickness of at least 0.2 mm or more is recommended. However, when the plate thickness increases, the space through which the gas can pass decreases, so it was necessary to increase the column diameter and height.

[0006] Therefore, 750 m 2 / m 3 A structured packing made of copper with a specific surface area exceeding 750 m² / m and a plate thickness of 0.1 mm or less, and a structured packing made of aluminum thinner than 0.2 mm are used above it. By doing so, even in an atmosphere with a high oxygen concentration, while maintaining extremely low reactivity with oxygen, the space through which the gas can pass is increased to suppress an increase in the column diameter, and a low-pressure column with a reduced column height is disclosed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, using copper for the material like the structured packing described in Patent Document 1 not only makes it relatively expensive, but also has a problem that when the structured packing is made of different materials such as copper and aluminum, labor such as equipment adjustment is caused due to the different materials.

[0009] Therefore, an object of the present invention is to provide an air separation device including a low-pressure column that is safe even in a high-concentration oxygen atmosphere and has a reduced column height without increasing the column diameter, even if the structured packing used in the bottom section of the low-pressure column is made of aluminum.

Means for Solving the Problems

[0010] To achieve the above object, the first air separation apparatus of the present invention is an air separation apparatus that separates and collects raw material air into nitrogen and oxygen by low-temperature distillation, and includes a high-pressure column that separates the raw material air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air, a low-pressure column that separates the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas and low-pressure liquid oxygen, and a main condenser that heat-exchanges the high-pressure nitrogen gas and the bottom liquid of the low-pressure column to generate rising gas in the low-pressure column. A regular packing is filled in the bottom section of the low-pressure column, and the regular packing is formed by laminating corrugated sheets made of aluminum. The corrugated sheet has a plate thickness of 0.2 mm or more, a specific surface area of 750 m 2 / m 3 or more, a wave inclination angle of 55° or more with respect to the horizontal, and a diameter of a curvature circle of 60% or more of the mountain height at the wave crest. Further, the corrugated sheet preferably has a specific surface area of 1100 m 2 / m 3 or less and a wave inclination angle of 75° or less with respect to the horizontal.

[0011] Further, the second air separation apparatus of the present invention includes a high-pressure column that separates raw material air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air, a low-pressure column that separates the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas and low-pressure liquid oxygen, and a main condenser that heat-exchanges the high-pressure nitrogen gas and the bottom liquid of the low-pressure column to generate rising gas in the low-pressure column. A regular packing is filled in the bottom section of the low-pressure column, and the regular packing is composed of a lower-side regular packing and an upper-side regular packing. The lower-side regular packing is formed by laminating corrugated sheets for the lower side made of aluminum. The corrugated sheets for the lower side have a plate thickness of 0.2 mm or more, a specific surface area of 750 m 2 / m 3 or more, a wave inclination angle of 55° or more with respect to the horizontal, and a diameter of a curvature circle of 60% or more of the mountain height at the wave crest. The upper-side regular packing is formed by laminating corrugated sheets for the upper side made of aluminum. The corrugated sheets for the upper side have a plate thickness of less than 0.2 mm and a specific surface area of 750 m 2 / m 3As described above, it is characterized in that the wave inclination angle is 45° or more with respect to the horizontal, and the wave crest has a curvature circle diameter of 50% or more of the mountain height. Further, the corrugated sheet for the lower side preferably has a specific surface area of 1100 m 2 / m 3 or less and a wave inclination angle of 75° or less with respect to the horizontal.

[0012] Furthermore, the air separation apparatus of the present invention is characterized in that the main condenser is provided at the bottom of the low-pressure column. Further, it may have an argon column for collecting argon.

Advantages of the Invention

[0013] According to the air separation apparatus of the present invention, even if the corrugated sheet forming the structured packing is made of aluminum and has a plate thickness of 0.2 mm or more, there are no safety problems even in a high-concentration oxygen atmosphere, and the height of the low-pressure column can be reduced while reducing the diameter of the low-pressure column. Therefore, the cold box of the air separation apparatus accommodating the low-pressure column and the like can also be made compact.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0015] First, as a preliminary study, the specific surface area (the surface area of the wave peaks existing in a unit volume), the wave inclination angle (the orientation of the wave peaks from the horizontal), the separation performance and the influence on the pressure loss due to the diameter of the curvature circle at the wave peak of the corrugated sheet constituting the structured packing were confirmed. Note that the high pressure and low pressure in the following description indicate the difference in relative pressure in each exemplary form, and do not specify the pressure range.

[0016] FIG. 1 and FIG. 2 are schematic views of a corrugated sheet (metal sheet) 10 constituting a general structured packing. It has a wave inclination angle α with respect to the horizontal, and the waveform is inclined. Also, the ratio of the diameter D of the curvature circle at the wave peak to the wave height H is defined as the top curvature circle diameter ratio. Here, using a distillation column with a column diameter of 300 mm and a packing height of 1500 mm, under conditions similar to the bottom section of the low-pressure column described later (bottom oxygen concentration 94 - 99.8%) and under conditions similar to the argon column (bottom oxygen concentration 70 - 80%), Table 1 shows the results of distillation tests in an argon-oxygen system by changing the top curvature circle diameter ratio of the structured packing.

[0017]

Table 1

[0018] The name of the packing is expressed as a: specific surface area, α: wave inclination angle, D: top curvature circle diameter ratio. Here, HETP (Height Equivalent of one Theoretical Plate) is the height of a theoretical plate (the packing length per theoretical plate), which represents the separation performance (the smaller the value, the higher the performance). The values in Table 1 are the measured HETP normalized by the HETP of the packing a750_α45D50.

[0019] Also, the pressure loss is the pressure difference between the top and the bottom of the column per unit packing length. The values in Table 1 are the pressure loss at a gas load with an F factor (Fs) of the superficial velocity based on the empty column of 1.7 m / s (kg / m 3 ) 0.5 normalized by the pressure loss of the packing a750_α45D50.

[0020] The corrugated sheet generally used for regular packings has a wave tilt angle of about 45° and a top curvature circle diameter ratio of 50%. However, as shown in Table 1, it was found that the separation performance of the packing a750_α45D80 with a top curvature circle diameter ratio of 80% is good only under the bottom section conditions in a high-concentration oxygen atmosphere. Based on this result and the properties described in paragraph

[0004] , in the bottom section of the low-pressure column, even if the material is aluminum, without reducing the plate thickness, by combining a larger specific surface area with a larger wave tilt angle, or a smaller specific surface area with a smaller wave tilt angle, it is suggested that the column diameter can be made thinner while reducing the column height, or the column height can be reduced at the same column diameter, or the performance described later can be improved. Based on this suggestion, the inventors of the present invention arrived at the invention described later.

[0021] (First Embodiment Example) FIG. 3 is a diagram showing a first embodiment example of an air separation apparatus of the present invention configured to collect oxygen, nitrogen, and argon by cryogenic liquefaction separation (low-temperature distillation) of compressed, purified, and cooled raw air in a high-pressure column, a low-pressure column, and an argon column.

[0022] The air separation apparatus 1 shown in this embodiment example includes, as main devices, a main condenser 300, a high-pressure column 500, a low-pressure column 600, and an argon column 700. The raw air is compressed by an air compressor 2, cooled to room temperature by an after-cooler 2a, and then introduced into a purification facility 3, where impurities such as carbon dioxide and moisture are adsorbed and removed. A part of the raw air purified by the purification facility 3 enters the cold box 110 through a path 21 and is introduced into the main heat exchanger 201. In this main heat exchanger 201, it is cooled by heat exchange with nitrogen gas (path 61) from the top of the low-pressure column, exhaust gas (path 62), and liquid oxygen supplied from the main condenser 300 through a path 57, and is led out to a path 22 and introduced as rising gas to the lower part of the high-pressure column 500.

[0023] In addition, a part of the purified raw air is pressurized and then supplied to the main heat exchanger 201 through a path 11, and after cooling, it is supplied below the high-pressure column 500 through a path 12.

[0024] Furthermore, a part of the purified raw air passes through path 31, is pressurized by compressor 4, cooled to normal temperature by aftercooler 4a, and further cooled to an intermediate temperature by main heat exchanger 201, and then is introduced into expansion turbine 5 and adiabatically expanded to the intermediate pressure of low-pressure column 600 to generate cold and become low-pressure raw air. The low-pressure raw air is supplied as rising gas from a position slightly above the middle of low-pressure column 600 through path 32.

[0025] In high-pressure column 500, the raw air supplied through path 22 undergoes gas-liquid contact with the reflux liquid flowing down inside the column, and while rising, nitrogen, which is a low-boiling component, is concentrated, and high-pressure nitrogen gas is generated at the top of the column. Also, the reflux liquid flowing down inside the column, including the liquid air supplied through path 12 below the column, becomes enriched in oxygen, which is a high-boiling component while descending, and high-pressure oxygen-enriched liquid air is generated at the bottom of the column. Below the column, the liquid air is withdrawn through path 53.

[0026] At the bottom of low-pressure column 600, main condenser 300 is provided. In this main condenser 300, high-pressure nitrogen gas and low-pressure liquid oxygen at the bottom of the low-pressure column described later indirectly exchange heat. The high-pressure nitrogen gas is liquefied in main condenser 300, and a part of it is supplied to heat exchanger 202 through path 51. After cooling, it is depressurized through path 52 and then supplied as reflux liquid to the top of low-pressure column 600. Also, the low-pressure liquid oxygen evaporates in main condenser 300 and becomes the rising gas of low-pressure column 600.

[0027] Also, the high-pressure oxygen-enriched liquid air generated at the bottom of high-pressure column 500 is supplied to heat exchanger 202 through path 55. After cooling, it is depressurized through path 56 and then introduced into argon condenser 400 at the top of argon column 700. The oxygen-enriched liquid air introduced into argon condenser 400 evaporates and is supplied to low-pressure column 600 through path 43. On the other hand, the liquid air withdrawn from below high-pressure column 500 through path 53 is supplied to heat exchanger 202, cooled, depressurized through path 54, and then supplied to the middle part of low-pressure column 600.

[0028] The reflux liquid supplied to the low-pressure column 600 flows down while coming into gas-liquid contact with the rising gas inside the column, and oxygen, which is a high-boiling component, is concentrated. As a result, low-pressure liquid oxygen (bottom liquid of the column) with a concentration of 99.5% or more is generated at the bottom of the column. Also, while the rising gas ascends, nitrogen, which is a low-boiling component, is concentrated, and low-pressure nitrogen gas is generated at the top of the column.

[0029] Also, an argon column feed gas with an argon concentration of 5 - 15% (the remaining components are almost oxygen) is withdrawn from the middle part of the low-pressure column 600 through path 63 and supplied to the bottom of the argon column 700. The supplied argon column feed gas ascends while concentrating the low-boiling component argon, and oxygen is removed to about 1%. The gas taken out from the top of the argon column 700 is supplied to the argon condenser 400. A part of it is liquefied and returned to the argon column 700 as reflux liquid, and the rest is collected as argon gas through path 71. Also, at the bottom of the argon column 700, liquefied oxygen with a reduced argon concentration is separated. This liquefied oxygen is returned from the lower part of the argon column 700 through path 72 to the lower part of the low-pressure column 600 and becomes the descending liquid.

[0030] Here, a plurality of structured packings are stacked inside the low-pressure column 600 and the argon column 700, respectively. The structured packing 600a filled in the bottom section of the low-pressure column 600 (below path 63. The gas-liquid contact section located at the lowest position inside the low-pressure column.) where the oxygen concentration becomes as high as 99.5% or more is formed by stacking a plurality of corrugated sheets as packings such that the inclined directions of the waveforms intersect, and is formed in a cylindrical shape. In the case of a large column diameter, it may also be formed from a plurality of blocks having a dividing surface perpendicular to the stacking direction of the corrugated sheets.

[0031] The packing forming the structured packing 600a is packing a750_α55D80 with a material of aluminum, a plate thickness of 0.2 mm, a specific surface area of 750 m 2 / m 3 , a wave inclination angle of 55°, and a top curvature circle diameter ratio of 80%. Since it has a plate thickness of 0.2 mm, even if it is aluminum, safety in a high-concentration oxygen atmosphere is ensured.

Example

[0032] The regular packing 600a used in the first morphological example was taken as Example 1-1. Furthermore, the one with a specific surface area of 850 m 2 / m 3 , a wave inclination angle of 60°, and a top curvature circle diameter ratio of 80% was taken as Example 1-2, the one with a specific surface area of 1100 m 2 / m 3 , a wave inclination angle of 75°, and a top curvature circle diameter ratio of 80% was taken as Example 1-3, the one with a specific surface area of 850 m 2 / m 3 , a wave inclination angle of 55°, and a top curvature circle diameter ratio of 60% was taken as Example 1-4, and the HETP and pressure loss per unit length were calculated.

[0033] Also, the material of the general packing that constitutes the regular packing used in the gas-liquid contact part other than the bottom section of the low-pressure column 600 is aluminum, with a plate thickness of 0.1 mm and a specific surface area of 750 m 2 / m 3 , a wave inclination angle of 45°, and a packing a750_α45D50 with a top curvature circle diameter ratio of 50% was used as a comparative example.

[0034] The results are shown in Table 2. Note that the column diameters are the same for each example and comparative example. For HETP and pressure loss, the values are based on setting the comparative example as 1.0. From the results in Table 2, within the range of a wave inclination angle of 55° or more and 75° or less, a specific surface area of 750 m 2 / m 3 or more and 1100 m 2 / m 3 or less, and within the range of a top curvature circle diameter ratio of 60% or more, the HETP and pressure loss are comparable to those of the conventional comparative example with a thin plate thickness. Therefore, it can be seen that by adopting the packing in each example, the column diameter can be reduced to the same level as the conventional comparative example with a thin plate thickness. Also, as shown in the preliminary study, it can be seen that a large top curvature circle diameter can cancel out the decrease in separation performance due to increasing the wave inclination angle and suppress the increase in column height.

[0035]

Table 2

[0036] (Second Embodiment Example) FIG. 4 is a diagram showing a low-pressure column 601 used in the air separation apparatus according to the second embodiment example of the present invention. The structured packing 601a filled in the bottom section of the low-pressure column 601 has a two-layer structure of a lower-side structured packing 602 and an upper-side structured packing 603. The lower-side structured packing 602 is provided at the lowermost 200 to 2000 mm, preferably 600 to 1200 mm of the low-pressure column 601. Similar to the first embodiment example, the material is aluminum, the plate thickness is 0.2 mm, and the specific surface area is 750 m 2 / m 3 , and it is formed by a structured packing a750_α55D80 having a wave inclination angle of 55° and a top curvature circle diameter ratio of 80%.

[0037] Since the oxygen concentration of the upper-side structured packing 603 is low, it is a general one with a material of aluminum, a thinner plate thickness, preferably 0.1 mm, and a specific surface area of 750 m 2 / m 3 , and it can be formed by a structured packing a750_α45D50 having a wave inclination angle of 45° and a top curvature circle diameter ratio of 50%.

Example

[0038] The structured packing 601a used in the second embodiment example was taken as Example 2-1. Also, as Example 2-2, for the packing of the lower-side structured packing 602, a packing having a specific surface area of 950 m 2 / m 3 , a wave inclination angle of 65°, and a top curvature circle diameter ratio of 80% was used, and for the packing of the upper-side structured packing 603, a packing having a specific surface area of 950 m 2 / m 3 , a wave inclination angle of 65°, and a top curvature circle diameter ratio of 80% was used. Also, as Example 2-3, for the packing of the lower-side structured packing 602, a packing having a specific surface area of 950 m 2 / m 3 , a wave inclination angle of 55°, and a top curvature circle diameter ratio of 80% was used, and for the packing of the upper-side structured packing 603, a packing having a specific surface area of 950 m 2 / m 3, one with a wave tilt angle of 55° and a top curvature circle diameter ratio of 80% was used. Further, as Example 2-4, for the packing of the lower-side regular packing 602, the specific surface area was 850 m 2 / m 3 , one with a wave tilt angle of 55° and a top curvature circle diameter ratio of 60% was used, and for the packing of the upper-side regular packing 603, the specific surface area was 850 m 2 / m 3 , one with a wave tilt angle of 45° and a top curvature circle diameter ratio of 60% was used.

[0039] Also, the lower-side regular packing 602 was formed of a packing with a material of copper, a plate thickness of 0.1 mm, a specific surface area of 750 m 2 / m 3 , a wave tilt angle of 45°, and a top curvature circle diameter ratio of 50%. The upper-side regular packing 603 was formed of a packing with a material of aluminum, a plate thickness of 0.1 mm, a specific surface area of 750 m 2 / m 3 , a wave tilt angle of 45°, and a top curvature circle diameter ratio of 50% as the regular packing 601a of the comparative example.

[0040] The results are shown in Table 3. Note that for each example and comparative example, the column diameter is the same, and the packing length of the lower-side regular packing 602 is 1040 mm. For HETP, pressure loss, and total packing length, the values are based on setting the comparative example as 1.0. For the increase and decrease in the bottom pressure of the tower, the bottom pressure of the comparative example is set as 1.0, and it is the ratio of increase and decrease relative to that. Since a decrease in the bottom pressure of the tower leads to a reduction in the power of the air compressor, that is, an improvement in the performance of the air separation device, it can be seen that all the examples are superior in performance as a whole compared to the comparative example.

[0041]

Table 3

[0042] As described above, for the packing constituting the regular packing filled in a high-oxygen concentration atmosphere such as the bottom section of the low-pressure column, even if it is made of aluminum, the plate thickness is 0.2 mm or more, and the specific surface area is 750 m 2 / m 3By adopting those with a wave tilt angle of 55° or more and a top curvature circle diameter ratio of 60% or more, a low-pressure column can be made compact at low cost without using copper, and furthermore, the cold box for accommodating them can also be made compact, and a safe air separation device can be obtained.

[0043] In the air separation devices of the above-described respective embodiments, argon can be recovered by an argon column, but an air separation device without an argon column may also be used. Further, in the above-described respective embodiments, a main condenser is provided at the bottom of the low-pressure column, and a high-pressure column is further provided integrally therewith, but the low-pressure column and the high-pressure column may be configured separately.

Description of Reference Numerals

[0044] 1…Air separation device, 2…Air compressor, 2a…Aftercooler, 3…Purification equipment, 4…Compressor, 4a…Aftercooler, 5…Expansion turbine, 10…Corrugated sheet, 11, 12, 21, 22, 31, 32, 43, 51, 52, 53, 54, 55, 56, 57, 61, 62, 63, 71, 72…Path, 110…Cold box, 201…Main heat exchanger, 300…Main condenser, 400…Argon condenser, 500…High-pressure column, 600…Low-pressure column, 600a, 601a…Regular packing, 602…Lower-side regular packing, 603…Upper-side regular packing, 700…Argon column

Claims

1. An air separation device that separates and collects nitrogen and oxygen by cryogenic distillation of raw air, comprising: a high-pressure column that separates the raw air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air; a low-pressure column that separates the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas and low-pressure liquid oxygen; a main condenser that exchanges heat between the high-pressure nitrogen gas and the bottom liquid of the low-pressure column to generate rising gas in the low-pressure column; a structured packing is filled in the bottom section of the low-pressure column; the structured packing is formed by laminating corrugated sheets made of aluminum, the corrugated sheet, has a plate thickness of 0.2 mm or more, The specific surface area is 750 m ２ / m ３ or more, has a wave inclination angle of 55° or more with respect to the horizontal, has a diameter of the curvature circle at the peak of the wave that is 60% or more of the mountain height, characterized air separation device.

2. The corrugated sheet has a specific surface area of 1100 m ２ / m ３ or less and a wave tilt angle of 75° or less with respect to the horizontal, and the air separation device according to claim 1 is characterized by this.

3. An air separation device that separates and collects nitrogen and oxygen by cryogenic distillation of raw air, comprising: a high-pressure column that separates the raw air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air; a low-pressure column that separates the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas and low-pressure liquid oxygen; a main condenser that exchanges heat between the high-pressure nitrogen gas and the bottom liquid of the low-pressure column to generate rising gas in the low-pressure column; a structured packing is filled in the bottom section of the low-pressure column; the structured packing is composed of a lower-side structured packing and an upper-side structured packing, the lower-side structured packing is formed by laminating corrugated sheets for the lower side made of aluminum, the corrugated sheet for the lower side, has a plate thickness of 0.2 mm or more, The specific surface area is 750 m ２ / m ３ or more, has a wave inclination angle of 55° or more with respect to the horizontal, has a diameter of the curvature circle at the peak of the wave that is 60% or more of the mountain height, the upper-side structured packing is formed by laminating corrugated sheets for the upper side made of aluminum, the corrugated sheet for the upper side, has a plate thickness of less than 0.2 mm, The specific surface area is 750 m ２ / m ３ or more, has a wave inclination angle of 45° or more with respect to the horizontal, has a diameter of the curvature circle at the peak of the wave that is 50% or more of the mountain height, characterized air separation device.

4. The corrugated sheet for the lower side has a specific surface area of 1100 m ２ / m ３ or less and a wave tilt angle of 75° or less with respect to the horizontal, and the air separation device according to claim 3 is characterized by this.

5. The air separation device according to any one of claims 1 to 4, characterized in that the main condenser is provided at the bottom of the low-pressure column.

6. The air separation device according to any one of claims 1 to 4, characterized in that it has an argon column for collecting argon.

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