A low-temperature distillation tower

Abstract

The present application discloses a cryogenic distillation tower, which relates to the technical field of distillation facilities and addresses the poor disaster resistance and construction difficulties of cryogenic distillation towers in related technologies. The cryogenic distillation tower comprises a shell assembly and distillation equipment. The shell assembly includes an inner shell, the inner shell having a first vacuum chamber formed therein, and at least a portion of the inner shell being buried below the ground surface. The distillation equipment is disposed in the first vacuum chamber. The cryogenic distillation tower of the present application is used to separate air, isotopes, and the like.

Description

Technical Field

[0001] The embodiments of the present application relate to, but are not limited to, the field of distillation facilities, and in particular to a cryogenic distillation tower. Background Art

[0002] As the main process equipment for air separation and isotope separation, the cryogenic distillation tower has a complex structure and involves multiple professional fields such as vacuum, low temperature, heat transfer, and pressure bearing. It is widely used in defense aviation, nuclear industry, oil and gas and other fields.

[0003] The low-temperature distillation towers that are widely used nowadays are mostly ground-supported and built at a positive elevation. When the tower height is very high, the distillation tower occupies a large space, has high requirements for earthquake resistance, wind load, and snow load, is difficult to build, difficult to repair and maintain, and has high operating costs. Summary of the Invention

[0004] The cryogenic distillation tower provided in the embodiment of the present application can save space above the ground surface, has a good ability to withstand natural loads, and is easy to construct and maintain.

[0005] An embodiment of the present application provides a low-temperature distillation tower, including a shell assembly and distillation equipment. The shell assembly includes an inner shell, a first vacuum chamber is formed inside the inner shell, and at least a portion of the inner shell is buried below the ground surface; the distillation equipment is arranged in the first vacuum chamber.

[0006] The cryogenic distillation tower provided in the embodiments of the present application utilizes the principle of cryogenic distillation to separate components of varying volatility in a mixture to purify the desired substance. The shell assembly protects the distillation equipment and provides the necessary operating environment. Specifically, the shell assembly includes an inner shell, the interior of which defines a first vacuum chamber. The distillation equipment is disposed within the first vacuum chamber. The first vacuum chamber thermally isolates the distillation equipment from the outside world, thereby reducing heat exchange between the distillation equipment and the outside world and improving the cryogenic distillation effect. Furthermore, at least a portion of the inner shell is buried below the ground surface. This arrangement improves the cryogenic distillation tower's ability to withstand disasters. First, wind and snow only generate loads above the ground surface. When at least a portion of the inner shell is located below the ground surface, this portion does not interact with wind and snow to generate loads. Compared to a case where the entire inner shell is located above the ground surface, the portion of the inner shell located below the ground surface effectively reduces the load-bearing area, thereby reducing wind loads, snow loads, and the like. Secondly, at least a portion of the inner shell is buried below the surface, where it interacts with the strata, firmly anchoring the inner shell to the strata. When the portion of the inner shell above the surface is subjected to loads or encounters natural disasters such as earthquakes, the inner shell's foundation is more secure, its load-bearing capacity is greater, and it is less likely to overturn. Thirdly, at least a portion of the inner shell is buried below the surface, which protects it from wind erosion, sunlight, and other factors, resulting in a longer lifespan and reduced maintenance costs. Therefore, burying at least a portion of the cryogenic distillation tower below the surface can effectively improve the tower's ability to withstand disasters. Furthermore, because the surface atmosphere is constantly flowing due to environmental influences, the specific heat capacity of the strata below the surface is greater than that of the flowing atmosphere. Therefore, the strata can also serve as a thermal insulation layer for the cryogenic distillation tower, reducing heat exchange between the cryogenic distillation tower and the atmosphere, thereby maintaining the distillation equipment within the cryogenic distillation tower at a suitable operating temperature. Furthermore, burying at least a portion of the inner shell underground can reduce the space occupied by the cryogenic distillation tower above the ground surface, thereby conserving space resources. A cryogenic distillation tower of the same size, when constructed at elevation, requires more support structures, resulting in a more complex structure and higher construction and maintenance costs. Compared to related art solutions in which the entire cryogenic distillation tower is constructed above the ground surface, the cryogenic distillation tower of the present application, in which at least a portion of the inner shell is buried below the ground surface, can conserve space above the ground surface, while also having a good ability to withstand natural loads, good thermal insulation, and convenient construction and maintenance.

[0007] In one possible implementation of the present application, the inner shell includes a first shell and a second shell, wherein the first shell is disposed above the ground surface; the second shell is buried below the ground surface, and the first shell and the second shell are fixedly connected; wherein the extension direction of the first shell and the extension direction of the second shell are both arranged along the direction of gravity. With such an arrangement, on the one hand, the inner shell can be split into multiple components, which facilitates the simultaneous processing and production of multiple components, and finally the multiple components can be assembled together, saving construction time; on the other hand, the first shell located above the ground surface can be detachably fixed to the second shell below the ground surface, which facilitates maintenance of the first shell and the distillation equipment inside it. In addition, the first shell and the second shell arranged vertically along the direction of gravity have better verticality and stability.

[0008] In one possible implementation of the present application, the first shell has a first dimension along the direction of gravity, and the second shell has a second dimension along the direction of gravity, with the second dimension being greater than or equal to the first dimension. With this arrangement, a larger portion of the inner shell is buried below the ground surface, resulting in a smaller area exposed to wind and snow loads, while a larger area is supported by the ground, thus providing a greater load-bearing capacity.

[0009] In one possible implementation of the present application, the inner shell further includes a mounting base, disposed between the first shell and the second shell. The mounting base is secured to the upper side of the ground, and the mounting base has a radial dimension greater than that of the second shell. This arrangement allows the mounting base to be stably secured to the upper side of the ground. The mounting base's larger radial dimension provides greater vertical support, thereby reducing the possibility of tilting the cryogenic distillation column.

[0010] In one possible implementation of the present application, the housing assembly further comprises an outer housing fixedly connected to the mounting base, and a second vacuum chamber is formed within the outer housing, with at least a portion of the second housing disposed within the second vacuum chamber. This arrangement, on the one hand, creates a double-layer vacuum structure with the second vacuum chamber, providing a higher fault tolerance and enabling better vacuum maintenance. On the other hand, the outer surface of the second housing is within the vacuum environment of the second vacuum chamber, making it less susceptible to environmental corrosion, thereby increasing the service life of the second housing.

[0011] In one possible implementation of this application, the second shell is suspended from the underside of the mounting base; alternatively, both the outer shell and the second shell are suspended from the underside of the mounting base. This arrangement, where the second shell is suspended, or both the outer shell and the second shell are suspended, can mitigate thermal stress caused by temperature differences, and a suspended installation offers better seismic resistance than a rigid connection.

[0012] In one possible implementation of the present application, the outer shell is made of a corrosion-resistant material, which can increase the service life of the outer shell and provide better protection for the second shell inside it.

[0013] In one possible implementation of the present application, the first vacuum chamber includes a first cavity located within a first shell and a second cavity located within a second shell; the distillation equipment includes a condenser, a distillation column, a reboiler, and a heater, the condenser, the distillation column, and the heater being connected in sequence, with the heater being used to heat the reboiler; the condenser is located in the first cavity, and the distillation column, the reboiler, and the heater are located in the second cavity. With this arrangement, equipment requiring high maintenance, such as the condenser, is placed in the first cavity for ease of maintenance, while equipment requiring low maintenance, such as the distillation column and reboiler, is placed in the second cavity, resulting in a more rational layout.

[0014] In one possible implementation of the present application, the distillation apparatus further includes multiple gas-liquid distributors, each including an interface portion. The interface portions of the multiple gas-liquid distributors are spaced apart along the axis of the distillation column and connected to the distillation column. The gas-liquid distributors can reduce mixing of gas and liquid. Providing multiple gas-liquid distributors can effectively reduce gas-liquid mixing caused by an overly long distillation column, thereby improving separation and purification effectiveness.

[0015] In one possible implementation of this application, a protective layer is provided on the outer surface of the distillation equipment. The protective layer is made of a heat-insulating and corrosion-resistant material. This configuration can reduce the maintenance requirements of the distillation equipment and improve the thermal insulation effect and the effect of low-temperature distillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a cryogenic distillation tower provided in an embodiment of the present application;

[0017] Figure 2 A schematic diagram of the structure of the inner shell of the cryogenic distillation tower provided in an embodiment of the present application;

[0018] Figure 3 A schematic structural diagram of a mounting base in a cryogenic distillation tower provided in an embodiment of the present application;

[0019] Figure 4 A schematic diagram of the structure of the outer shell of the cryogenic distillation tower provided in an embodiment of the present application;

[0020] Figure 5 A schematic diagram of the suspended installation of the second shell and the outer shell in the cryogenic distillation tower provided in an embodiment of the present application;

[0021] Figure 6 A schematic diagram of the arrangement of the distillation columns in the cryogenic distillation tower provided in an embodiment of the present application;

[0022] Figure 7 This is a schematic diagram of the arrangement of the gas-liquid distributor in the cryogenic distillation tower provided in an embodiment of the present application.

[0023] Reference numerals:

[0024] 1-shell assembly; 11-inner shell; 111-first shell; 112-second shell; 113-mounting seat; 12-first vacuum chamber; 121-first cavity; 122-second cavity; 13-outer shell; 14-second vacuum chamber; 2-distillation equipment; 21-condenser; 22-distillation column; 23-reboiler; 24-gas-liquid distributor; 3-formation. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the specific technical solutions of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application but are not intended to limit the scope of the present application.

[0026] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more.

[0027] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left" and "right" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to changes in the orientation of the components in the drawings.

[0028] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integrated connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0029] In the embodiments of the present application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0030] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0031] The embodiments of the present application provide a cryogenic distillation tower, which is the main process equipment for air separation and isotope separation, and is widely used in defense aviation, nuclear industry, oil and gas and other fields.

[0032] Reference Figure 1 、 Figure 2 and Figure 3 The low-temperature distillation tower provided in the embodiment of the present application includes a shell assembly 1 and a distillation device 2. The shell assembly 1 includes an inner shell 11. A first vacuum chamber 12 is formed inside the inner shell 11, and at least part of the inner shell 11 is buried below the ground surface; the distillation device 2 is arranged in the first vacuum chamber 12, wherein the ground surface is the upper surface of the stratum 3.

[0033] The low-temperature distillation tower provided in the embodiment of the present application, the distillation equipment 2 can use the principle of low-temperature distillation to separate components with different volatility in the mixture to purify the required substances, and the shell assembly 1 provides protection for the distillation equipment 2 and provides the environment required for the distillation equipment 2 to work.

[0034] Specifically, the shell assembly 1 includes an inner shell 11, and a first vacuum chamber 12 is formed inside the inner shell 11. The distillation equipment 2 is arranged in the first vacuum chamber 12. The first vacuum chamber 12 can thermally isolate the distillation equipment 2 from the outside world to reduce the heat exchange between the distillation equipment 2 and the outside world, thereby improving the effect of low-temperature distillation.

[0035] On this basis, at least part of the inner shell 11 is buried below the ground surface. Such an arrangement can improve the ability of the cryogenic distillation tower to resist disasters. Specifically:

[0036] First, wind, snow, etc. will only form loads on the upper side of the ground. When at least part of the inner shell 11 is located on the lower side of the ground, this part does not interact with the wind and snow to generate loads. Compared with the inner shell 11 being located on the upper side of the ground, the part of the inner shell 11 being located on the lower side of the ground can effectively reduce the force-bearing area, thereby reducing wind loads or snow loads, etc.

[0037] Secondly, at least part of the inner shell 11 is buried below the ground surface, and this part interacts with the stratum 3, thereby firmly fixing the inner shell 11 in the stratum 3. When the part of the inner shell 11 located above the ground surface is subjected to load or encounters natural disasters such as earthquakes, the foundation of the inner shell 11 is more solid, the bearing capacity is stronger, and it is less likely to overturn.

[0038] Thirdly, at least part of the inner shell 11 is buried below the ground surface and is not affected by wind erosion, sunlight, etc., is less affected by weather factors, has a longer service life, and can reduce maintenance costs. Therefore, burying at least part of the low-temperature distillation tower below the ground surface can effectively improve the ability of the low-temperature distillation tower to resist disasters.

[0039] At the same time, since the surface atmosphere is constantly flowing due to the influence of the environment, the specific heat capacity of the layer 3 below the surface is larger than that of the flowing atmosphere. Therefore, the layer 3 can also be used as an insulating layer of the low-temperature distillation tower to reduce the heat exchange between the low-temperature distillation tower and the atmosphere, so that the distillation equipment 2 in the low-temperature distillation tower is maintained at a suitable operating temperature.

[0040] In addition, burying at least part of the inner shell 11 underground can reduce the space occupied by the cryogenic distillation tower above the surface, thereby saving space resources. Cryogenic distillation towers of the same size require more supporting structures when constructed at a normal elevation, resulting in a more complex structure and higher construction and maintenance costs. By adopting the solution of the present application, a cryogenic distillation tower with a larger axial dimension can be constructed. For example, the axial dimension of a CO isotope cryogenic distillation tower partially buried below the surface can reach 177 meters.

[0041] Compared with the solution in the related art in which the low-temperature distillation tower is constructed as a whole on the upper side of the ground, the low-temperature distillation tower of the present application has at least a portion of its inner shell buried on the lower side of the ground, which can save space on the upper side of the ground. At the same time, it has a good ability to resist natural loads, good thermal insulation effect, and is convenient for construction and maintenance.

[0042] It should be noted that the inner shell 11 in the present application has a variety of possible structural forms. The inner shell 11 can be spherical, block-shaped, cylindrical, or conical, among which the cylindrical shape can be a cylinder, a triangular prism, a quadrangular prism, a hexagonal prism, etc., and the conical shape can be a truncated cone, a quadrangular cone, etc., and the present application does not impose any restrictions on this.

[0043] Reference Figure 1In a possible embodiment of the present application, the inner shell 11 is a cylindrical structure. Along the central axis direction, the inner layer can be partially buried below the ground surface. The upper end surface of the inner shell 11 can be a plane or a curved surface. Correspondingly, the lower end surface of the inner shell 11 can also be a plane or a curved surface. In a possible embodiment of the present application, the upper end surface of the inner shell 11 is a hemispherical surface convex outward, and the lower end surface of the inner shell 11 is a plane.

[0044] In addition, the inner shell 11 can be an integral structure or can be assembled from multiple components. Figure 2 and Figure 3 In a possible embodiment of the present application, the inner shell 11 includes a first shell 111 and a second shell 112, the first shell 111 is arranged on the upper side of the ground; the second shell 112 is buried on the lower side of the ground, and the first shell 111 and the second shell 112 are fixedly connected.

[0045] Specifically, the first vacuum chamber 12 includes a first cavity 121 located inside the first shell 111, and a second cavity 122 located inside the second shell 112; the opening of the first cavity 121 is located on the lower side of the first shell 111, and the opening of the second cavity 122 is located on the upper side of the second shell 112. The opening of the first shell 111 and the opening of the second shell 112 are connected to each other. In order to ensure the sealing of the first vacuum chamber 12, the fixed connection between the first shell 111 and the second shell 112 is sealed.

[0046] Among them, the fixed connection can be fixed by a non-detachable method such as welding, or by a detachable method such as clamping, fastener connection, etc. With such an arrangement, on the one hand, the inner shell 11 is split into multiple components, which is convenient for simultaneous processing and production of multiple components, and finally the multiple components are assembled together, saving construction time; on the other hand, the first shell 111 located on the upper side of the ground surface can be detachably fixed to the second shell 112 on the lower side of the ground surface, which facilitates maintenance of the first shell 111 and the distillation equipment 2 inside it.

[0047] It should be noted that the first shell 111 and the second shell 112 can be made of different materials. For example, the first shell 111 is located on the upper side of the ground and is easily eroded by sunlight, wind, snow, etc., and can be made of a material that is light in weight and has good wind and sun protection properties. The second shell 112 is located on the lower side of the ground and can be made of a material that is heavy in weight, has a strong load-bearing capacity, and has good corrosion resistance. Optionally, the first shell 111 and the second shell 112 are both welded with stainless steel.

[0048] In addition, the structures of the first shell 111 and the second shell 112 can be the same or different. For example, the second shell 112 adopts a cylindrical structure and the first shell 111 adopts a truncated cone structure. This application does not limit this. It only needs to ensure that the first cavity 121 and the second cavity 122 are connected. Figure 2 、 Figure 3 and Figure 4 In a possible embodiment of the present application, the first shell 111 adopts a flat-bottomed cylindrical structure, the second shell 112 adopts a convex-topped cylindrical structure, and the radial dimensions of the first shell 111 are consistent with the radial dimensions of the second shell 112, and the radial dimensions of the first cavity 121 are also consistent with the radial dimensions of the second cavity 122.

[0049] In order to maintain the verticality of the cryogenic distillation tower and reduce the influence of its own weight on its stability, refer to Figure 2 、 Figure 3 and Figure 4 In a possible embodiment of the present application, the extension direction of the first shell 111 and the extension direction of the second shell 112 are both set along the direction of gravity, wherein the extension direction refers to the length direction of the component, or the direction of the central axis of the rotating body. For example, the extension direction of the first shell 111 of the cylindrical structure is the direction of its central axis.

[0050] In addition, the present application does not limit the axial size of the inner shell 11. In order to further improve the disaster resistance of the cryogenic distillation tower, Figure 2 、 Figure 3 and Figure 4 In one possible embodiment of the present application, the first shell 111 has a first dimension along the direction of gravity, and the second shell 112 has a second dimension along the direction of gravity, with the second dimension being greater than or equal to the first dimension. With this arrangement, a larger portion of the inner shell 11 is buried beneath the ground, reducing its area subject to wind and snow loads. A larger area is supported by the ground layer 3, resulting in a stronger load-bearing capacity.

[0051] Reference Figure 3 and Figure 4 In one possible embodiment of the present application, the inner shell 11 further includes a mounting base 113, which is disposed between the first shell 111 and the second shell 112. The mounting base 113 is fixed to the upper side of the ground, and the radial dimension of the mounting base 113 is larger than the radial dimension of the second shell 112. This arrangement allows the mounting base 113 to be stably fixed to the upper side of the ground. The larger radial dimension of the mounting base 113 provides more support in the vertical direction, thereby reducing the possibility of tilting the cryogenic distillation column.

[0052] Among them, the structure of the mounting base 113 has many possible forms. The mounting base 113 can be a ring structure, a frame structure, etc. The first shell 111 and the second shell 112 can be connected to the mounting base 113 respectively, and the interior of the mounting base 113 forms a accommodating space, which is a part of the first vacuum chamber 12. Alternatively, the first shell 111 and the second shell 112 are directly connected, and at least one of the first shell 111 and the second shell 112 is fixedly connected to the mounting base 113. This application does not impose any restrictions on this.

[0053] In a possible embodiment of the present application, the shell assembly 1 also includes an outer shell 13, which is fixedly connected to the mounting seat 113, and a second vacuum chamber 14 is formed inside the outer shell 13, and at least a portion of the second shell 112 is disposed in the second vacuum chamber 14.

[0054] With such an arrangement, on the one hand, the second vacuum chamber 14 and the first vacuum chamber 12 form a double-layer vacuum structure, which has a higher fault tolerance and can better maintain the vacuum; on the other hand, the outer surface of the second shell 112 is in the vacuum environment of the second vacuum chamber 14 and is not easily corroded by the environment, thereby improving the service life of the second shell 112.

[0055] It should be noted that the outer shell 13 can be fixedly connected to the second shell 112, and the outer shell 13 can also be fixedly connected to the mounting base 113. In order to reduce the thermal stress caused by the ambient temperature difference and improve the seismic performance, refer to Figure 4 and Figure 5 In one possible embodiment of the present application, the second housing 112 is suspended from the underside of the mounting base 113; alternatively, both the outer housing 13 and the second housing 112 are suspended from the underside of the mounting base 113. Suspended mounting can alleviate thermal stress caused by temperature differences and offers better seismic resistance than rigid connections.

[0056] The present application does not limit the material of outer shell 13. In one possible embodiment, outer shell 13 is made of a corrosion-resistant material. This configuration can extend the service life of outer shell 13 and provide better protection for second shell 112 within it. Alternatively, outer shell 13 can be made of materials such as stainless steel and carbon steel.

[0057] On this basis, the first vacuum chamber 12 is further equipped with a distillation device 2, referring to Figure 3 、 Figure 4 and Figure 5In one possible embodiment of the present application, the distillation equipment 2 includes a condenser 21, a distillation column 22, a reboiler 23, and a heater. The condenser 21, the distillation column 22, and the heater are connected in sequence, and the heater is used to heat the reboiler 23. The condenser 21 is located in the first cavity 121, and the distillation column 22, the reboiler 23, and the heater are located in the second cavity 122. With this arrangement, equipment requiring high maintenance, such as the condenser 21, is placed in the first cavity 121 for ease of maintenance, while equipment requiring low maintenance, such as the distillation column 22 and the reboiler 23, is placed in the second cavity 122, resulting in a more reasonable layout.

[0058] Among them, the condenser 21 can use liquid nitrogen as a cold source, the distillation column 22 is filled with fillers, and the connected condenser 21, the distillation column 22 and the reboiler 23 can be welded and fixed to form a distillation module. A plurality of distillation modules are set in the first vacuum chamber 12. Figure 6 , multiple distillation modules are arranged in a projection array along the direction of gravity. It should be noted that the distillation module can also be fixed on the fixed base in a suspended manner, and multiple groups of heaters can be set to improve the fault tolerance rate. When the distillation equipment 2 is operating normally, the heating power is controlled at low power to increase the service life of the heater.

[0059] In addition, the distillation equipment 2 also includes sensors, which can be set at various positions of the heater and the distillation module so that the operator can control the operating status of the distillation equipment 2. The sensors may include temperature sensors; the distillation equipment 2 also includes a vacuum pump, a vacuum connector, a valve, etc. The vacuum pump is used to evacuate the first vacuum chamber 12 and the second vacuum chamber 14, and the vacuum connector is used to connect the pipes, cables, etc. of the distillation equipment 2 to the outside world. Among them, the vacuum pump, vacuum connector, etc. are all arranged in the first cavity 121, that is, located on the upper side of the ground surface, to facilitate daily maintenance.

[0060] Since the axial dimension of the low-temperature distillation tower of the present application is large, that is, the length of the distillation column 22 is long, in order to improve the effect of low-temperature distillation, Figure 7 In one possible embodiment of the present application, the distillation column 22 is formed by welding multiple distillation sections in sequence along its axis. The distillation equipment 2 also includes multiple gas-liquid distributors 24. The gas-liquid distributors 24 include interface portions. The interface portions of the multiple gas-liquid distributors 24 are spaced apart along the axis of the distillation column 22 and connected to the distillation column 22. The gas-liquid distributors 24 can reduce mixing of gas and liquid. Providing multiple gas-liquid distributors 24 can effectively reduce gas-liquid mixing caused by an overly long distillation column 22, thereby improving the separation and purification effect.

[0061] To extend the service life of the distillation effect of the distillation equipment 2, in one possible embodiment of the present application, a protective layer made of a heat-insulating and corrosion-resistant material is optionally provided on the outer surface of the distillation equipment 2. For example, the outer surface of the distillation column 22 is wrapped with insulation cotton, and the heater adopts an armored structure. This configuration can not only reduce the maintenance requirements of the distillation equipment 2, but also improve the thermal insulation effect, reduce heat leakage, and reduce the vaporization rate of the medium to be separated along the axial direction of the cryogenic distillation column, thereby improving the effect of cryogenic distillation.

[0062] On this basis, the present application also provides a construction method for a low-temperature distillation tower. The construction of the low-temperature distillation tower is carried out according to the steps of first installing the outer shell 13, then installing the second shell 112 and the distillation equipment 2 in sequence, and finally installing the first shell 111. When installing the outer shell 13 and the inner shell 11, it is necessary to control the vertical deviation of each component in the shell assembly 1 from the horizontal plane so that the low-temperature distillation tower is in a vertical state after construction is completed. In addition, during the welding process of the components, the welds are subjected to multiple liquid nitrogen freezing and reheating treatments, and after welding is completed, negative pressure helium leak detection and 100% radiographic detection are performed. The leak detection indicators and flaw detection films are judged to be qualified before assembly, thereby ensuring the stability and sealing of the structure.

[0063] The serial numbers of the embodiments of this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are only preferred embodiments of this application and do not limit the scope of the patent of this application. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the scope of patent protection of this application.

Claims

1. A cryogenic distillation tower, characterized in that: include: a housing assembly comprising an inner housing, wherein a first vacuum chamber is formed inside the inner housing, and at least a portion of the inner housing is buried below the ground surface; a distillation device, wherein the distillation device is disposed in the first vacuum chamber; The inner shell includes a second shell, and the second shell is buried under the ground surface; The first vacuum chamber includes a second cavity located inside the second housing; The distillation equipment includes a distillation column, and the distillation column is located in the second cavity; The distillation equipment further includes a plurality of gas-liquid distributors, each of which includes an interface portion. The interface portions of the plurality of gas-liquid distributors are spaced apart along the axial direction of the distillation column and are connected to the distillation column.

2. The cryogenic distillation tower according to claim 1, characterized in that The inner shell comprises: a first shell, the first shell being disposed above the ground surface; The first shell and the second shell are fixedly connected; Wherein, the extension direction of the first shell and the extension direction of the second shell are both arranged along the direction of gravity.

3. The cryogenic distillation tower according to claim 2, characterized in that The first shell has a first size along the direction of gravity, the second shell has a second size along the direction of gravity, and the second size is greater than or equal to the first size.

4. The cryogenic distillation tower according to claim 2 or 3, characterized in that The inner shell further includes a mounting seat, which is disposed between the first shell and the second shell. The mounting seat is fixed to the upper side of the ground surface, and a radial dimension of the mounting seat is greater than a radial dimension of the second shell.

5. The cryogenic distillation tower according to claim 4, characterized in that The housing assembly further includes an outer housing fixedly connected to the mounting seat, and a second vacuum chamber is formed inside the outer housing. At least a portion of the second housing is disposed in the second vacuum chamber.

6. The cryogenic distillation tower according to claim 5, characterized in that The second shell is suspended on the lower side of the mounting seat; or, both the outer shell and the second shell are suspended on the lower side of the mounting seat.

7. The cryogenic distillation tower according to claim 5, characterized in that The outer shell is made of corrosion-resistant material.

8. The cryogenic distillation tower according to claim 2 or 3, characterized in that The first vacuum chamber includes a first cavity located inside the first housing; The distillation equipment includes a condenser, a reboiler and a heater. The condenser, the distillation column and the heater are connected in sequence. The heater is used to heat the reboiler. The condenser is located in the first cavity, and the reboiler and the heater are located in the second cavity.

9. The cryogenic distillation tower according to any one of claims 1 to 3, characterized in that The outer surface of the distillation equipment is provided with a protective layer, and the protective layer is made of a heat-insulating and corrosion-resistant material.

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