JP2001165565A - Cold box, corresponding air rectifier, and corresponding construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a cold box which can reduce the construction cost. SOLUTION: This cold box 1 is composed of a low-temperature assembly 2, an outer jacket 3, at least one heat insulator 4 filled between the said low- temperature assembly and the said outer jacket, and others. The said outer jacket 3 is equipped with a main part 20 which surrounds the main low- temperature assembly 6 apart on the whole, and at least one partial sub part 21 which surrounds apart at least one of the sub low-temperature elements 16 and 19 jutted out sideways from the said main part and projecting from the said low-temperature assembly. This cold box is used in, for example, an air rectifier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold box which is provided, for example, in an air rectifying apparatus so as to surround the rectification column and insulates the inside thereof.

[0002]

2. Description of the Related Art An air rectification apparatus is provided with a rectification column operated at a very low temperature. In order to limit heat exchange with the outside world, the cryogenic assembly (comprising such a rectification column and its associated equipment) is surrounded by an insulator such as perlite, glass wool or rock wool. The insulation is supported by an outer jacket or cladding. These outer jackets or the like are spaced around the perimeter of the cold assembly and are supported on the inside or outside of the framework. The equipment configured in this way is generally called a cold box.

[0003] The outer diameter of the cold box depends on the outer diameter of the cold assembly housed therein and the minimum thickness of the insulation required to ensure adequate insulation performance. The outer diameter of the cold box is, for example,
The amount of insulation used, the surface area of the outer jacket,
It directly affects the total construction cost of the device, such as through the size of the skeleton required to support the outer jacket. Furthermore, if the method of manufacturing the cold box in advance in the factory and transporting the cold box to the site cannot be adopted because the outer diameter of the cold box is too large, the construction cost of the apparatus is further increased.

[0004] Before the cold box is installed on the site, it is desirable to perform assembling work of the cold box as much as possible in a factory. By doing so, the production deadline can be controlled, quality specifications can be satisfied, and the increased costs for on-site work can be reduced. In the case of local work, for example, weather conditions may be bad.

[0005]

SUMMARY OF THE INVENTION Accordingly, one of the objects of the present invention is to solve such a problem by providing a cold box having a small outer diameter.

[0006]

SUMMARY OF THE INVENTION A cold box according to the present invention comprises a cryogenic assembly having a main cryogenic element and some auxiliary cryogenic elements, and an outer jacket ("") spaced around the cryogenic assembly. outer jacke
t ") and at least one insulator filled between said cryogenic assembly and said outer jacket, said outer jacket surrounding said main cryogenic element, or At least one of a main part, which at least substantially surrounds the main part at a distance and which entirely surrounds it, and at least one of the auxiliary cryogenic elements projecting laterally outwardly from said main part and projecting from said cryogenic assembly, At least one local auxiliary part, spaced apart and surrounding, wherein each said main cryogenic element comprises a cryogenic column, a portion of such a cryogenic column, a heat exchanger and a stacked combination thereof. Wherein each of the projecting auxiliary cold elements is a gas-liquid separator, a reservoir,
Connection piping, a portion of such connection piping, and a device for monitoring or controlling the operation of the cryogenic assembly.

According to various embodiments of the present invention,
The cold box of the present invention has any of the following features alone or in a technically feasible combination.

(A) each said main cryogenic element is selected from the group consisting of a rectification and / or mixing column, a part of such a column, a heat exchanger, and a stacked combination thereof; Either.

(B) each of the thermal insulators is substantially exposed to atmospheric pressure, and the dimensions of the outer jacket and the main part are determined as follows: (I = 1,..., N), each main cold element has four angular sectors (“angular se
ctor ") (S11, S12, S13, S14; S21,
S22, S23, S24;...) Whose angular sectors are mutually dependent and substantially equal, and these angular sectors are concentrated on the longitudinal axis (A) of the main cryogenic element of interest. Furthermore, the four angular sectors are represented by “j” (j = 1,..., 4), and the four angular sectors from the main cold element of interest to the outer jacket, or If the minimum lateral distance to the other main cryogenic element located next to the main cryogenic element of interest is represented by "dij", the value of "dij" is defined by the following equation:

(Equation 6) (C) The dimensions of the main part of the outer jacket are defined by the following formula:

(Equation 7) (D) The dimensions of the main part of the outer jacket are defined by the following formula:

(Equation 8) (E) The dimensions of the main part of the outer jacket are defined by the following formula:

(Equation 9) (F) The dimensions of the main part of the outer jacket are defined by the following formula:

(Equation 10) (G) At least one of the heat insulators is pearlite.

(H) at least one of said main cryogenic elements has a lateral dimension of more than 0.4 m.

(I) The main cryogenic element has a lateral dimension exceeding 1 m.

Further, the air rectifying device of the present invention is characterized by including the cold box defined above.

[0013] The method of the present invention is also a method for on-site construction of a cold box as defined above, comprising the following features: the cold box is connected to substantially the entire cold assembly and to the main part of the outer jacket. Parts, and some auxiliary parts are prefabricated in the form of packets that are at least partially missing (“packet”); transport the packets; Completing the outer jacket by supplementing the at least partially missing auxiliary part; and then filling the insulation between the outer jacket and the cold assembly.

In one embodiment of the method according to the invention described above, before transporting the packet, a blanking panel is provided on the outer jacket at the location of the at least partially missing auxiliary part. After transporting the packet, removing the blanking panel; then completing the outer jacket by supplementing the at least partially missing auxiliary part.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a cold box according to the present invention will be described with reference to the accompanying drawings.
In addition, in FIG. 1 to FIG. 4 described below, each component is not drawn with accurate relative dimensions for easy viewing of the drawings.

FIG. 1 shows an outline of a cold box according to the present invention. This cold box 1 constitutes a part of an air rectification device. Cold box 1
Is installed in a vertical position on the air rectification equipment construction site.

The cold box 1 includes a low-temperature assembly 2 located inside, an outer jacket 3 (indicated by a two-dot chain line in FIG. 1) (“outer jacket”),
And a heat insulator 4. This heat insulator 4
Is perlite, for example, filled between the low temperature assembly 2 and the outer jacket 3 and is substantially exposed to atmospheric pressure. Although only a part of the heat insulator 4 is shown in the drawing, the heat insulator 4 is actually filled in a space surrounded by the low-temperature assembly 2 and the outer jacket 3. Note that a plurality of types of heat insulators 4 may be used at the same time.

Further, the cold box 1 is provided with a skeleton supporting the outer jacket 3 outside the outer jacket 3 as in the prior art. In addition, this frame is to make the figure easy to see,
It is not depicted in the figure.

The cryogenic assembly 2 is a conventional cryogenic assembly, comprising a main cryogenic element 6 and some auxiliary cryogenic elements. The main cryogenic element 6 is a two-stage air rectification column, which itself includes a medium-pressure column 7, a low-pressure column 8, and a vaporizer / condenser 9 as in the related art. In the vaporizer / condenser 9, heat exchange is performed between nitrogen from the top of the medium pressure column 7 and oxygen from the bottom of the low pressure column 8.

The auxiliary cryogenic element is only partially shown in the figure for the sake of clarity. They are as follows.

(A) Piping 12: Air to be rectified is introduced into the medium pressure column 7 through this piping. This air is pressurized, purified, and cooled in a main heat exchanger (not shown) before introduction.

(B) Pipe 13: Oxygen gas is extracted from the bottom of the low-pressure column 8 through this pipe, and the extracted oxygen gas is heated in a main heat exchanger (not shown).

(C) Pipe 14: An expansion valve is provided in the middle of this pipe, and lean liquid LP (almost pure nitrogen) is introduced from the top of the medium pressure column 7 to the top of the low pressure column 8.

(D) Piping 15: An expansion valve is also provided in the middle of this piping, and the rich liquid LR (oxygen-enriched air) is extracted from the bottom of the medium pressure column 7.

(E) Gas-liquid separator 16, in which the above-mentioned rich liquid is divided into a liquid flow and a gas flow, and these two flows are separately introduced into the middle stage of the low-pressure column 8. You.

(F) Pipe 18: Through this pipe, low-purity nitrogen NR (“residual nitrogen”) is withdrawn from the top of the low-pressure column 8 and sent to a main heat exchanger (not shown).

The gas-liquid separator 16 and the downstream portion 19 of the pipe 15 connected thereto form a portion locally projecting laterally of the low-temperature assembly 2 with respect to the two-stage rectification column 6. ing.

As shown in FIGS. 1 and 2, the outer jacket 3 has a main part 20 and an auxiliary part 21. The main part 20 has a cylindrical shape, has a square base, and has a common vertical axis as the axis A of the two-stage rectification column 6. The main part 20 surrounds the periphery of the two-stage rectification column 6 as follows. That is, the distances between the four side surfaces of the main part and the two-stage rectification column 6 are d11, d12, d13, and d14, respectively, and these distances are each about 0.5 m.

The above distances d11, d12, d13, d1
4 has four angular sectors (“angular secto”).
r "), corresponding to the minimum lateral distance from the two-stage rectification column 6 to the main part 20 of the outer jacket 3. These four angular sectors are interdependent. And are concentrated on axis A. Thus, each of these angular sectors corresponds to a split angle of about 90 degrees.

From the above, d11 + d12 + d13 + d1
4 ≒ 2 [m].

Instead of setting as described above, d11, d11
Assuming that the values of 12, d13, and d14 are each approximately 0.4 m, the total value thereof is approximately 1.6 m.

Further, the main part 20 of the outer jacket 3 surrounds the pipes 14, 15 and 18 over substantially the entire length thereof. The distance between the main part 20 and these pipes is set so that heat insulation for these pipes is sufficiently ensured. These pipes 14, 1
Since the dimensions of 5 and 18 depend on the production capacity and performance of the cryogenic assembly 2, in practice the distance for this insulation depends on the production capacity and function of the cryogenic assembly 2. Therefore, in the case of a two-stage rectification column having a diameter of about 2 m, the distance can be about 300 mm.

Auxiliary part 21 of outer jacket 3
Is a local protrusion formed at a position facing the gas-liquid separator 16 on the side surface of the main part 20, and has a parallelepiped ("parallelepipedal") shape. The local protrusion projects laterally outward from the main part 20 and is connected to the gas-liquid separator 16 and the downstream portion 19 of the pipe 15.
Around them with enough space to insulate them. As before, the distance for this insulation depends on the production capacity and function of the cryogenic assembly 2.

For example, the distance required for heat insulation of the gas-liquid separator 16 is about 0.5 m, and the distance required for heat insulation of a part 19 of the pipe is about 300 mm.

As described above, the dimensions of the outer jacket 3 are set so that the pearlite 4 surrounds the low temperature assembly 2 with a sufficient thickness so that the low temperature assembly 2 can be operated in a good condition. You.

Further, the outer diameter of the outer jacket 3 is smaller than that of a conventional outer jacket having a "parallelepipedal" shape. The conventional outer jacket is manufactured with an outer diameter dimension that entirely surrounds all parts of the low-temperature assembly 2, as shown by the broken lines in FIG. The reason is that in a conventional cold box, the auxiliary cold element 16
In contrast, in the cold box 1 according to the present invention, a portion having a large outer diameter in the lateral direction is the outer part of the cold box 1. The main part 2 of the outer jacket 3 is limited to only the auxiliary part 21 of the jacket 3
This is because the outer diameter of 0 is set without considering the thickness of the heat insulator 4 required for heat insulation of the gas-liquid separator 16 and a part 19 of the pipe.

As described above, according to the cold box 1 of the present invention, the outer diameter of the cold box 1 can be reduced, and as a result, the construction cost can be reduced.

In FIGS. 1 and 2, the auxiliary part 21 is exaggerated and drawn larger than the main part 20. Actually, the volume of the auxiliary part 21 is, for example, about 1 m ³ to about 10 m ³ , while the volume of the main part 20 is, for example, about 25 m ³ to about 400 m ³ . When the cold box 1 is installed vertically, the height of the auxiliary part 21 is, for example, 7 m or less. The thickness of the auxiliary part 21 is typically 100 mm or more, preferably 300 mm.

Furthermore, the number of auxiliary parts 21 depends on the low-temperature assembly 2 and can be several dozen in some cases.

In general, the auxiliary cryogenic element surrounded by auxiliary part 21 monitors or controls the operation of the gas-liquid separator, the reservoir, the connecting tubing, a portion of such connecting tubing, and the cryogenic assembly. The device is one selected from the group consisting of:

The storage tank, which is one of the auxiliary parts 21 projecting outward, has various volumes, for example, 3 m ^3.
It has a ~25m ³ about the volume. If the cold box 1 is installed vertically, the height of these auxiliary cold elements is, for example, about 6 m or less.

FIG. 1 shows a cold box according to the invention.
2 and 3, the auxiliary part 21 of the outer jacket 3 projects over almost the entire height of the cold box 1 or over almost the entire circumference.

In the latter example, an auxiliary part 21 is provided at the lower end portion of the cold box 1, so that the cold box 1 has a shape in which the base portion is widened. In this case, the base part and the other parts of the cold box 1 can be preliminarily manufactured in a factory into two packets, and these packets can be transported to a construction site and assembled there.

FIG. 3 shows another example of the cold box 1 according to the present invention. In this example, the cryogenic assembly 2 comprises two main cryogenic elements 24 and 25, which are arranged side by side. For example, these main cryogenic elements 24 and 25 are each part of a double column rectification column. In that case, for example, the main cryogenic element 24 is a medium pressure column provided with a vaporizer / condenser, and the main cryogenic element 25 is a low pressure column.

[0045] Also in this example, the cryogenic assembly 2 includes an auxiliary cryogenic element. However, only three protruding elements (indicated by reference numeral 26) are drawn in FIG.
Other elements are omitted. Outer jacket 3
The main part 20 has a vertical cylindrical shape,
The shape of the base is rectangular. Main part 20
Generally surrounds the main cryogenic elements 24 and 25.

Focusing on the first main cold element 24, the minimum distance between the element 24 and the three adjacent sides of the main part 20 of the outer jacket 3 and the second main cold element 25 is shown in FIG. Where d11, d12, d
13 and d14.

These distances d11, d12, d13, d
14, four angular sectors s11, s12, s
It corresponds to the minimum lateral distance from the first main cryogenic element 24 to the main part 20 of the outer jacket 3 or to the adjacent second main cryogenic element 25 for 13 and s14. Here, these four angular sectors are interdependent and approximately equal and are centered on the axis A of the first main cold element 24. Therefore, each of these angular sectors corresponds to a division angle of about 90 degrees.

Similarly, focusing on the second main cryogenic element 25, the element 25, the three adjacent sides of the main part 20 of the outer jacket 3 and the first main cryogenic element 24
The minimum distance between d21 and d21 in FIG.
It is represented by d22, d23 and d24.

These distances d21, d22, d23, d
24 indicates four angular sectors s21, s22, s
This corresponds to the minimum lateral distance from the second main cryogenic element 25 to the main part 20 of the outer jacket 3 or to the adjacent first main cryogenic element 24 for 23 and s24. Here, these four angular sectors are mutually dependent and approximately equal and are concentrated on the axis A of the second main cold element 25. Therefore, each of these angular sectors corresponds to a division angle of about 90 degrees.

The above distances d11, d12, d13, d1
4, d21, d22, d23, and d24 are each about 0.5 m. Therefore, the total value of these distances is about 4 m.

The outer jacket 3 has three auxiliary parts 21. Each auxiliary part 21 is,
Surrounding the auxiliary cryogenic elements 26 projecting with respect to the main cryogenic elements 24 and 25, thereby ensuring sufficient insulation for these auxiliary cryogenic elements 26.

As in the case of the example shown in FIGS. 1 and 2,
By attaching locally overhanging parts (auxiliary parts 21) to the main part 20 which entirely surrounds the main cryogenic elements 24 and 25, while ensuring sufficient insulation for the whole cryogenic assembly 2, The outer diameter of the cold box 1 can be reduced.

More generally, this principle is based on n (n ≧ n)
The present invention can be applied to a cold box having the main low temperature element of 1). Here, the main cryogenic element is any selected from the group consisting of rectification and / or mixing columns, parts of such columns, heat exchangers, and combinations thereof.

As described above, the outer diameter of the main part 20 of the cold box 1 is entirely surrounded around the double tower air rectification column and the main heat exchanger (for cooling the air to be purified). It can be set as follows.

Preferably, the dimensions of the main part 20 of the outer jacket 3 are set as follows. That is,
When each main low-temperature element is represented by a symbol “i” (i = 1,..., N), each main low-temperature element has four angular sectors, and these angular sectors are mutually dependent and substantially Equally, these angular sectors are centered on the longitudinal axis of the element of interest.

Further, the four angular sectors are represented by “j” (j = 1,..., 4), and
The minimum lateral distance for one angular sector from the main cryogenic element of interest to the outer jacket or to another main cryogenic element located next to the main cryogenic element of interest, expressed in terms of "dij", the value of "dij" is defined by the following equation:

[Equation 11] Cold box constructed based on the above conditions,
It is very compact, while at the same time allowing the main cryogenic element to be well insulated from the outside world.

More preferably, using the same reference numerals as above, the dimensions of the main part 20 are defined by the following equations:

(Equation 12) More preferably, using the same reference numerals as above, the dimensions of the main part 20 are defined by the following formula:

(Equation 13) More preferably, using the same reference numerals as above, the dimensions of the main part 20 are defined by the following formula:

[Equation 14] More preferably, using the same reference numerals as above, the dimensions of the main part 20 are defined by the following formula:

(Equation 15) In the example shown in FIGS. 1 to 3, the skeleton supporting the outer jacket 3 is arranged outside the outer jacket 3. If such framing elements are arranged inside the outer jacket 3, they are considered to form part of the outer jacket. Therefore, in such a case, the distance from such a skeleton element to the main low-temperature element (i) may be used as the minimum distance "dij".

Further, when the cross-sectional shape of the main part 20 of the outer jacket 3 is not constant, the minimum distance "dij" is used in a cross-section in which the above dimensional constraint conditions can be considered. The value is used.

FIG. 4 shows another example of the cold box 1 according to the present invention. In this example, the axes A of a plurality of main cryogenic elements
Are not on a common plane parallel to one side of the main part 20 of the outer jacket 3 and the four angular sectors and their corresponding distances dij
It shows the method of selection.

When applying the above-described formula, the other main low-temperature elements to be considered are only the other main low-temperature elements arranged adjacent to each other. Therefore, when two or more main cryogenic elements are arranged in a stacked state, as in the case shown in FIGS. 1 and 2, these main cryogenic elements are considered as one main cryogenic element. Will be handled.

Of course, the principle described above can be applied to the outer jacket 3 having another shape. For example, the cylindrical main part 20 may rest on a base other than a rectangle or a square (for example, a circular base).

The dimensional conditions mentioned above can be applied particularly when the lateral dimension (for example, diameter) exceeds 1 m, and preferably when it exceeds 0.4 m.

Next, a preferred example of the method for constructing a cold box according to the present invention will be described with reference to FIG.

First, the cold box 1 is manufactured in advance in a factory in the form of a packet including the low-temperature assembly 2, the main part 20 of the outer jacket 3, and the skeleton supporting the cold box. At this stage, only one of the auxiliary parts 21 (shown in the upper part of FIG. 4) of the outer jacket 3 is partially manufactured, and the other auxiliary parts 21 are not manufactured.

The blanking panel 30 (shown by a broken line in the figure) is attached to a portion where the auxiliary part 21 is missing or a portion where the auxiliary part 21 is partially missing. If the auxiliary parts 21 are missing, these blanking panels 30 cover the corresponding sides of the main part 20 of the outer jacket 3 and form, for example, a continuous shape to these sides. Alternatively, it is attached so as to cover an opening provided at a position in the side surface where the auxiliary part 21 will be attached later.

The blanking panel 30 used for the part where the auxiliary part 21 is partially missing is a flat plate.
It is attached to the corresponding area of the auxiliary part 21.
In contrast, the other blanking panels 30
It has a shape adapted to the projection area corresponding to the projecting auxiliary cold element 26.

The packet produced in this way is then transported to a construction site. Blanking panel 3
0 serves to protect the inside of the cold box 1 during this transport. Then, at the construction site, the blanking panel 30 is removed, the missing auxiliary part is attached, the partially missing auxiliary part is completed, and then the insulation 4 is filled in the outer jacket 3. Thus, the cold box 1 is completed.

For this reason, the previously manufactured packet has a smaller horizontal dimension than the completed cold box 1. Therefore, according to the construction method according to the present invention, when there are certain restrictions on the transportable dimensions, a packet having the same dimensions as the completed cold box 1 is preliminarily manufactured for the cold box including the low-temperature assembly. In comparison with the case where the cold box is transported, a cold box having a larger production capacity can be manufactured and transported in advance.

As described above, according to the construction method described above, a larger cold box can be manufactured in advance in the form of a transportable packet.
The construction cost of those cold boxes can be reduced.

If the protruding low-temperature element 26 projects slightly outside the main part 20 of the outer jacket 3, the depression corresponding to the blanking panel 30 is formed as shown in FIG. May be formed.

As an alternative to the above construction method, a packet pre-manufactured in the factory is once transported to the vicinity of the site where the cold box is to be constructed, where the cold box is completed and then the completed cold box is completed. The box can be moved to the actual construction site.

As another modification of the present invention not described above, there is also a form in which only a part of the auxiliary part 21 is missing from a pre-manufactured packet.

The principles of the invention described above can, of course, be applied to the construction of a cold box, where the cold assembly housed in the cold box uses any type of low temperature technology. The principles of the present invention can be used particularly when purifying air (or a gas separated from air), and more generally when treating gases that are purified or liquefied at low temperatures.

[0074]

According to the cold box of the present invention, a cold box having a larger production capacity than before can be manufactured in a factory in advance, and then transported to a construction site to complete it. Therefore, the construction cost of the cold box can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing an outline of a cold box according to the present invention.

FIG. 2 is a schematic sectional view taken along the line BB of FIG. 1;

FIG. 3 is a schematic sectional view similar to FIG. 2 of another cold box according to the present invention.

FIG. 4 is a schematic sectional view similar to FIG. 2 of another cold box according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cold box, 2 ... Low temperature assembly, 3 ... Outer jacket, 4 ... Heat insulator, 6 ... Two-stage rectification column (main low temperature element), 7 ... Medium Pressure column, 8: low pressure column, 9: vaporizer / condenser, 12, 13, 14, 15, 18 ... piping, 16 ... gas-liquid separator, 19 ... piping 15 Downstream part, 20 ... Main part, 21 ... Auxiliary part, 24 ... Main low temperature element (for example, medium pressure column), 25 ... Main low temperature element (for example, low pressure column), 26 ... Auxiliary cryogenic element, 30 ... blanking panel.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Bernard-Sornière, France, 92700 Coroombe, Rue Rene-Lege 25 (72) Inventor Gilet Braquet, France, 60340 Saint-Los-des-Lans, Abnu-Max Dormoy 45

Claims (13)

[Claims] 1. A main cryogenic element (6; 24, 25) and some auxiliary cryogenic elements (12-16, 18, 19; 26).
A low temperature assembly (2) comprising: an outer jacket (3) surrounding the low temperature assembly at a distance; and at least one insulator (4) filled between the low temperature assembly and the outer jacket. A cold box (1) comprising: a main part (20) surrounding the main cold element, or at least a majority of the main cold element, with a space therearound. ); And an auxiliary cold element (1) projecting laterally outward from said main part and projecting from said cold assembly.
6, 19; 26) at least one local auxiliary part (21), spaced apart around at least one of:
Wherein each said main cryogenic element is any one selected from the group consisting of a cryogenic column, a portion of such a cryogenic column, a heat exchanger, and a stacked combination thereof; Each protruding auxiliary cryogenic element is selected from the group consisting of a gas-liquid separator, a reservoir, connecting piping, a portion of such connecting piping, and a device for monitoring or controlling the operation of the cryogenic assembly. A cold box. 2. The cold box of claim 1, wherein each of the main cryogenic elements comprises a rectification and / or mixing column, a portion of such a column, a heat exchanger, and a stack thereof. The selected combination is one selected from the group consisting of: 3. The cold box according to claim 1, wherein each of the thermal insulators is exposed to substantially atmospheric pressure, and wherein the main part of the outer jacket is provided. (2
The dimensions of 0) are defined as follows: each main cold element (6; 24, 25) is denoted by the symbol "i" (i = 1,...).
, N), each of the main low-temperature elements (6; 24, 25) has four angular sectors (S11, S12, S1).
3, S14; S21, S22, S23, S24;
), These angular sectors are interdependent and nearly equal, and these angular sectors are concentrated on the longitudinal axis (A) of the main cold element of interest;・ Set the sector to “j” (j =
1, 4) and other main low-temperatures for these four angular sectors, which are arranged from the main cold element of interest to the outer jacket or next to the main cold element of interest. When the minimum horizontal distance to the element is represented by “dij”, respectively, “dij”
Is defined by the following equation: 4. The cold box according to claim 3, wherein the dimensions of the main part of the outer jacket are defined by the following equation: ## EQU2 ## 5. The cold box according to claim 4, wherein the dimensions of the main part of the outer jacket are defined by the following formula: 6. The cold box according to claim 5, wherein the dimension of the main part (20) of the outer jacket (3) is defined by the following equation: 7. Cold box according to claim 6, wherein the dimensions of the main part (20) of the outer jacket (3) are defined by the following formula: 8. The cold box according to claim 1, wherein the heat insulator comprises:
At least one is perlite. 9. A cold box according to claim 1, wherein at least one of said main cryogenic elements has a lateral dimension of more than 0.4 m. 10. The cold box according to claim 9, wherein the main cryogenic element has a lateral dimension of more than 1 m. 11. An air rectification device comprising at least one cold box according to claim 1. Description: 12. A method for on-site construction of a cold box according to claim 1, comprising: a cold box (1), a cold box (1); ) With the main part (20) of the outer jacket (3) and some auxiliary parts (21) pre-fabricated in the form of packets that are at least partially missing; Completing said low temperature assembly (2) as required; completing said outer jacket (20) by supplementing said at least partially missing auxiliary part (21); The space between the outer jacket (3) and the cold assembly (2) is filled with a thermal insulator (4). 13. The method according to claim 12, comprising: before transporting the packet, at the location of the at least partially missing auxiliary part (21) of the outer jacket, Blanking panel (30)
After transporting the packet, removing the blanking panel (30); and then replenishing the outer jacket (20) by supplementing the at least partially missing auxiliary part (21). Finalize.