Ultrahigh-purity gas or isotope separation equipment and system based on capillary force driving

Abstract

The invention discloses an ultra-pure gas or isotope separation device based on capillary force driving, and the device comprises a rectification unit which is formed by stacking a plurality of microtubes; the micro-tube rectification unit is arranged in the shell; the diameter of each micropipe is in a range of 0.3 mm-1 mm, and a gas-liquid phase exchange hole is formed in the pipe wall of each micropipe, so that the micropipes provide a liquid phase channel for liquid to flow under the action of capillary force of the micropipes and surface tension of the gas-liquid phase exchange holes in the rectification process of ultra-pure gas or isotope to be rectified; according to the equipment and the system, the rectification unit is small in size and high in heat and mass transfer efficiency, rectification is achieved by horizontally placing the rectification unit, and the requirement for the height space is low.

Description

Technical Field

[0001] The present application relates to the field of distillation technology, and in particular to a device and system for ultra-high purity gas or isotope separation driven by capillary force. Background Art

[0002] Distillation technology is mainly based on the different boiling points of each component in the mixture. The mixture is partially vaporized by heating, and then the components with different boiling points are separated during the condensation process. Specifically, when the mixture is heated, the light component (low boiling point component) will be vaporized first, while the heavy component (high boiling point component) is relatively difficult to vaporize. During the condensation process, the light component will be condensed into liquid first, while the heavy component will remain more in the gas phase. Through multiple cycles of vaporization and condensation, a relatively concentrated low-boiling point component can be obtained in the final vapor phase, and a relatively concentrated high-boiling point component can be obtained in the final liquid phase. This simultaneous mass transfer and heat transfer process is the basic principle of distillation. In the distillation process, the heat and mass transfer effect seriously affects the separation efficiency. Traditional distillation towers are generally divided into plate towers and packed towers.

[0003] For substances with relatively low volatility, especially the separation of ultra-high purity electronic gases and even isotopes, the use of traditional distillation towers requires a height of hundreds or even thousands of meters. The distillation equipment is too large, which makes it very difficult to apply in actual engineering.

[0004] Therefore, there is an urgent need in the art to develop an ultra-high purity gas or isotope separation device and system based on capillary force drive, in which the distillation unit is small in size and has high heat and mass transfer efficiency, and distillation is achieved by horizontally placing the distillation unit, with low height space requirements. Summary of the invention

[0005] The purpose of the present application is to provide a device and system for ultra-high purity gas or isotope separation based on capillary force drive, wherein the distillation unit of the device and system is small in size and has high heat and mass transfer efficiency, and distillation is achieved by placing the distillation unit horizontally, with low height space requirements.

[0006] The present application provides a device for ultra-high purity gas or isotope separation based on capillary force drive, comprising:

[0007] A distillation unit, wherein the distillation unit is formed by stacking a number of microtubes together;

[0008] a housing, wherein the micro-tubular distillation unit is disposed within the housing;

[0009] The diameter of the microtube is in the range of 0.3mm-1mm, and a gas-liquid exchange hole is arranged on the tube wall of each microtube so that during the distillation process of the ultra-high purity gas or isotope to be distilled, the microtube provides a liquid phase channel for liquid flow under the action of the capillary force of the microtube and the surface tension of the gas-liquid exchange hole, and the external space outside the microtube is configured for gas flow.

[0010] In another preferred example, the distillation unit has a first end and a second end opposite to the first end. During the distillation process, the ultra-high purity gas or isotope to be distilled that is condensed into liquid at the second end flows in the liquid phase channel along the first axial direction of the distillation unit under the action of the capillary force of the microtube and the surface tension of the gas-liquid phase exchange hole, and the ultra-high purity gas or isotope to be distilled that is heated into gas at the first end moves in the external space outside the microtube along the second axial direction of the distillation unit under the action of the pressure difference, and the second axial direction is opposite to the first axial direction.

[0011] In another preferred example, the first axial direction is a direction flowing from the second end to the first end, and the second axial direction is a direction flowing from the first end to the second end.

[0012] In another preferred example, the microtube includes a gas-liquid exchange section. When the gas in the external space and the liquid in the liquid phase channel flow, heat and mass transfer are carried out in the gas-liquid exchange section of the microtube through the gas-liquid exchange holes, so that the heavy component gas located in the external space is converted into liquid and enters the liquid phase channel, and the light component liquid located in the liquid phase channel is converted into gas and enters the external space, and separation and purification are achieved by repeated reciprocation.

[0013] In another preferred embodiment, the ultra-high purity gas or isotope to be distilled is high purity argon.

[0014] In another preferred example, the gas moves along the second axial direction, and the liquid moves along the first axial direction.

[0015] In another preferred example, during the distillation process, the plurality of microtubes are placed horizontally or tilted, and the first end of the distillation unit and the second end of the distillation unit are at substantially the same height level or at different height levels.

[0016] In another preferred embodiment, the distillation unit is placed horizontally or inclined.

[0017] In another preferred embodiment, during the distillation process, the housing and the distillation unit are placed flat on a horizontal plane.

[0018] In another preferred example, the first axial direction and the second axial direction are both parallel to a horizontal plane.

[0019] In another preferred embodiment, the length of the microtube is in the range of 500 mm-1000 mm.

[0020] In another preferred embodiment, the plurality of microtubes are stacked together to form a cylinder, and the distance between the centers of two adjacent microtubes is in the range of 1 mm to 2 mm.

[0021] In another preferred embodiment, the pore size of the gas-liquid exchange hole is in the range of 0.02 mm-0.05 mm.

[0022] In another preferred embodiment, the gas-liquid phase exchange holes are evenly arranged in the circumferential direction and the axial direction of the microtube.

[0023] In another preferred embodiment, the center distance between two adjacent gas-liquid exchange holes in the axial direction of the microtube is 0.05 mm-0.1 mm.

[0024] In another preferred embodiment, the center distance between two adjacent gas-liquid exchange holes in the circumferential direction of the microtube is 0.05 mm-0.1 mm.

[0025] In another preferred embodiment, the distance between two adjacent gas-liquid exchange holes on the microtube wall of the same cross section of the microtube is 0.05 mm-0.1 mm.

[0026] In another preferred embodiment, the capillary force should be greater than or equal to the gas-liquid phase pressure difference, and the gas-liquid phase pressure difference refers to the difference between the static pressure head of the liquid in the liquid phase channel and the static pressure head of the gas flowing in the external space outside the microtube.

[0027] In another preferred embodiment, the liquid at the first end can be used to continuously evaporate to generate gas, and can also be collected to become the product of the device.

[0028] In another preferred embodiment, the gas-liquid exchange section of the microtube is a part of the microtube.

[0029] In another preferred example, the device also includes a condenser, which is located at the second end of the distillation unit and is configured to condense the heavy component gas or heavy isotopes in the ultra-high purity gas or isotopes to be distilled in a gaseous state into a liquid, and the reboiler is located at the first end of the distillation unit and is configured to heat the light component gas or light isotopes in the ultra-high purity gas or isotopes to be distilled in a liquid state into a gas.

[0030] A second aspect of the present application provides a cascade system for ultra-high purity gas or isotope separation based on capillary force drive, wherein the system comprises one or more of the above-mentioned ultra-high purity gas or isotope separation devices based on capillary force drive connected in series.

[0031] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. It should be understood that the drawings described below are only some implementation examples of the present invention, and ordinary technicians in this field can also obtain other implementation examples based on these drawings without paying creative work.

[0033] Figure 1 It is a schematic diagram of the overall structure of a distillation unit of an ultra-high purity gas or isotope separation device based on capillary force drive according to the present application;

[0034] Figure 2 It is a partial structural schematic diagram of a distillation unit of an ultra-high purity gas or isotope separation device based on capillary force drive according to the present application;

[0035] Figure 3 It is a schematic diagram of the structure of the micro-tube of the distillation unit of the ultra-high purity gas or isotope separation device based on capillary force drive according to the present application.

[0036] In the accompanying drawings, the following are marked:

[0037] 1-Distillation unit

[0038] 11-First End

[0039] 12-Second end

[0040] 2-Microtubules

[0041] 21-Gas-liquid phase exchange hole

[0042] 200-Liquid Phase Channel DETAILED DESCRIPTION

[0043] Through extensive and in-depth research, the inventors have developed for the first time a device and system for ultra-high purity gas or isotope separation based on capillary force drive. The device uses a clever structure, capillary force and surface tension to achieve heat and mass transfer between gas and liquid phases, and can be used for the purification of ultra-high purity gas and isotope separation. The structure is small in size, and the separation of ultra-high purity gas and isotopes can be achieved by placing the distillation unit horizontally. Compared with traditional distillation towers, the device and system for ultra-high purity gas or isotope separation based on capillary force drive of the present application greatly reduces the space requirement in height, and has more practical engineering applications.

[0044] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0045] the term

[0046] As used herein, the term “axial direction” refers to a direction along its length, and the term “circumferential direction” refers to a direction of its circumference, which is a direction perpendicular to the axial direction.

[0047] As used herein, the terms "distillation unit" and "microtubular distillation unit" are used interchangeably.

[0048] As used herein, a "distillation process" is a process that achieves separation based on the differences in boiling points of different isotopes of argon.

[0049] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the application documents of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements. Expressions such as multiple, multiple, and multiple include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0050] In the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0051] This application has at least one of the following advantages

[0052] (a) The capillary force-driven ultra-high purity gas or isotope separation device and system of the present application can be used for the purification of ultra-high purity gas and isotope separation;

[0053] (b) The size of the device and system for ultra-high purity gas or isotope separation based on capillary force drive of the present application is much smaller than that of the traditional distillation tower, and has more practical engineering applications;

[0054] (c) The capillary-driven ultra-high purity gas or isotope separation device and system of the present application provides a distillation unit with an ingenious structure, which utilizes the combined effect of the capillary force and surface tension of the microtube to achieve the distillation process;

[0055] (d) The distillation unit in the capillary-driven ultra-high purity gas or isotope separation equipment and system of the present application can achieve the purification of ultra-high purity gas and isotope separation by horizontal placement or slightly inclined placement. Compared with the traditional distillation tower, it does not need to occupy space in the height direction and has more practical engineering applications.

[0056] To make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that these are only some examples that the present invention may take for the reader, but are not intended to limit the scope of the present invention.

[0057] See also Figure 1-3 The present application provides a device for separation of ultra-high purity gas or isotope driven by capillary force, comprising: a distillation unit 1 and a housing (not shown), wherein the microtube distillation unit 1 is arranged in the housing, and the distillation unit 1 is formed by stacking a number of microtubes 2; the diameter of the microtube 2 is in the range of 0.3 mm-1 mm, and a gas-liquid exchange hole 21 is arranged on the wall of each microtube 2, so that during the distillation process of the ultra-high purity gas or isotope to be distilled, the microtube 2 provides a liquid phase channel 200 for liquid flow under the action of the capillary force of the microtube 2 and the surface tension of the gas-liquid exchange hole 21, and the external space outside the microtube 2 is configured for gas flow; in one embodiment, the ultra-high purity gas or isotope to be distilled is high-purity argon. The device can also be used to prepare high-abundance argon isotopes (for example, 40 Preferably, a plurality of microtubes 2 are stacked together to form a cylinder, and the center distance between two adjacent microtubes 2 is within the range of 1 mm to 2 mm.

[0058] The distillation unit 1 has a first end 11 and a second end 12 opposite to the first end 11, and the first end 11 and the second end 12 of the microtube are fixed by two sieve plates respectively. During the distillation process, the ultra-high purity gas or isotope to be distilled which is condensed into liquid at the second end 12 flows in the liquid phase channel 200 along the first axial direction of the distillation unit 1 under the action of the capillary force of the microtube 2 and the surface tension of the gas-liquid phase exchange hole 21, and the ultra-high purity gas or isotope to be distilled which is heated into gas at the first end 11 moves in the second axial direction of the distillation unit 1 in the external space outside the microtube 2 under the action of the pressure difference, and the second axial direction is opposite to the first axial direction. That is, the gas moves along the second axial direction, and the liquid moves along the first axial direction. The first axial direction is the direction from the second end 12 to the first end 11, and the second axial direction is the direction from the first end 11 to the second end 12.

[0059] The microtube 2 includes a gas-liquid exchange section, and the gas-liquid exchange section of the microtube 2 is a part of the microtube 2. When the gas in the external space and the liquid in the liquid phase channel 200 flow, heat and mass transfer are carried out in the gas-liquid exchange section of the microtube 2 through the gas-liquid exchange hole 21, so that the heavy component gas in the external space is converted into liquid and enters the liquid phase channel 200, and the light component liquid in the liquid phase channel 200 is converted into gas and enters the external space. Specifically, the opening (gas-liquid exchange hole 21) on the tube wall is a gas-liquid exchange interface, which facilitates heat and mass transfer between gas and liquid. The liquid phase flows horizontally in the tube, and the gas phase flows horizontally outside the tube, and gas-liquid exchange is carried out at the opening.

[0060] In one embodiment, the capillary force-driven ultra-high purity gas or isotope separation device of the present application also includes a condenser (not shown) and a reboiler (not shown), the condenser is located at the second end of the distillation unit and is configured to condense the heavy component gas or heavy isotopes in the ultra-high purity gas or isotopes to be distilled in a gaseous state into a liquid, and the reboiler is located at the first end of the distillation unit and is configured to heat the light component gas or light isotopes in the ultra-high purity gas or isotopes to be distilled in a liquid state into a gas. When the distillation starts, the gas is cooled and liquefied into liquid through the condenser at the second end 22. The liquid flows downward in the microtube to the first end 11 of the distillation unit 1 by gravity (when the distillation unit is tilted) and capillary force. The light components in the liquid at the first end 11 are heated by the reboiler to generate gas. The gas flows toward the second end 22 (along the second axial direction) outside the microtube by pressure difference to reach the second end 22. The gas-liquid flow process transfers heat and mass through the gas-liquid phase exchange hole 21 to bring the heavy components to the liquid phase and the light components to the gas phase. Separation and purification are achieved by repeated reciprocation. The liquid at the first end 21 can be used for continuous condensation or collected to become the product of the device.

[0061] In one embodiment, a plurality of microtubes 2 are placed horizontally or obliquely on a horizontal plane, that is, the distillation unit 1 is placed horizontally or slightly obliquely on a horizontal plane. By placing the distillation unit horizontally or obliquely to achieve distillation, compared with a traditional vertically placed distillation tower, the space requirement in height is low and the distillation unit has more practical application value. The first end 11 of the distillation unit 1 and the second end 12 of the distillation unit are at the same height level or different height levels (in the case of oblique placement). In one embodiment, the inclination angle of the oblique placement can be 0-45 degrees. In one embodiment, when a plurality of microtubes 2 are placed horizontally on a horizontal plane, the first axial direction and the second axial direction are both parallel to the horizontal plane.

[0062] In one embodiment, the length of the micro tube 2 is in the range of 500 mm to 1000 mm as required.

[0063] In the present application, in order to achieve the desired gas-liquid mass transfer efficiency, a microtube 2 consisting of uniform openings is constructed. By adjusting the spacing and pore size between the openings, the permeability between the microtubes 2 can be freely set. Based on the effective medium approximation theory (EMA), on a scale much larger than the opening spacing, such a microtube 2 can be considered to be uniform and isotropic with a constant effective permeability.

[0064] In the microtube structure, the key to preventing flooding is to control the pressure difference between the liquid phase and the gas phase, and to use capillary force to maintain the flow of liquid in the microchannel. Capillary force can absorb liquid into the microchannel (liquid phase channel 200). In order to prevent the liquid phase from entering the gas phase, the capillary force must be large enough to overcome the pressure difference between the gas phase and the liquid phase. This pressure difference is generated by the flow of liquid in the liquid phase channel 200.

[0065] The capillary force must be able to maintain the flow of the liquid in the liquid phase channel 200 without causing the liquid to overflow into the gas phase channel (the external space outside the microtube 2). This requires that the size and structure of the liquid phase channel 200 of the microtube be properly designed so that the liquid can flow stably in the microchannel.

[0066] The pressure difference generated by the flow of liquid in the liquid phase channel 200 is the same as the pressure difference between the gas and liquid phases. In the distillation unit composed of a plurality of microtubes 2 of the present application, the flow of liquid and gas is interrelated. The pressure difference generated by the flow of liquid in the liquid phase channel 200 must be balanced with the pressure difference between the gas and liquid phases to maintain a stable flow and separation process. If these two pressure differences are inconsistent, the flow of liquid or gas will be unstable, affecting the separation efficiency.

[0067] In the liquid phase channel 200, there is a phase interface between the liquid and the gas. Capillary force plays a key role at this phase interface, maintaining the flow of the liquid in the liquid phase channel 200 while preventing the liquid from entering the gas phase channel. The force balance at this phase interface requires that the pressure difference (capillary force) generated by the liquid flow matches the pressure difference between the gas and liquid phases.

[0068] The gas-liquid phase pressure difference ΔP is the difference between the liquid static pressure head and the vapor static pressure head:

[0069] ΔP=P liquid -P vapor =(ρ liquid -ρ vapor )·g·h

[0070] Among them, ρ liquid and ρ vapor are the liquid and vapor densities respectively, g is the gravitational acceleration, and h is the height of the liquid column, the height of the liquid in the direction of the microtube diameter.

[0071] The pressure difference due to capillary force is calculated as follows:

[0072] P cap =2γ / R

[0073] Wherein, γ is the tension coefficient of the liquid in the microtube, and R is the size and radius of the gas-liquid phase exchange hole 21 on the tube wall.

[0074] Therefore, in the design of the microtube 2, it is necessary to ensure that the capillary force is greater than or equal to the gas-liquid phase pressure difference. Based on the above, preferably, the microtube 2 is set to the following size, the gas-liquid phase exchange holes 21 are evenly arranged in the circumferential direction and axial direction of the microtube, the pore size of the gas-liquid phase exchange holes 21 is in the range of 0.02mm-0.05mm, and the center distance between two adjacent gas-liquid phase exchange holes 21 in the axial direction of the microtube 2 is 0.05mm-0.1mm. The center distance between two adjacent gas-liquid phase exchange holes 21 in the circumferential direction of the microtube 2 is 0.05mm-0.1mm.

[0075] The present application also provides a cascade system for ultra-high purity gas or isotope separation based on capillary force drive, the system comprising one or more ultra-high purity gas or isotope separation devices based on capillary force drive as described above connected in series, wherein one or more of the distillation units are arranged in the shell.

[0076] A large number of technical features are recorded in the specification of this application, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded.

[0077] All documents mentioned in this application are considered to be included in the disclosure of this application as a whole, so that they can be used as the basis for modification when necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art can make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A device for ultra-high purity gas or isotope separation based on capillary force drive, characterized in that: include: A distillation unit (1), wherein the distillation unit (1) is formed by stacking a plurality of microtubes (2); shell , the micro-tubular distillation unit (1) is arranged in the housing; The diameter of the microtube (2) is in the range of 0.3 mm to 1 mm, and a gas-liquid phase exchange hole (21) is provided on the tube wall of each microtube (2), so that during the distillation process of the ultra-high purity gas or isotope to be distilled, the microtube (2) provides a liquid phase channel (200) for liquid flow under the action of the capillary force of the microtube (2) and the surface tension of the gas-liquid phase exchange hole (21), and the external space outside the microtube (2) is configured to allow gas to flow.

2. The device according to claim 1, characterized in that The distillation unit (1) has a first end (11) and a second end (12) opposite to the first end (11). During the distillation process, the ultra-high purity gas or isotope to be distilled, which is condensed into liquid at the second end (12), flows in the liquid phase channel (200) along a first axial direction of the distillation unit (1) under the action of the capillary force of the microtube (2) and the surface tension of the gas-liquid phase exchange hole (21). The ultra-high purity gas or isotope to be distilled, which is heated into gas at the first end (11), moves in an external space outside the microtube (2) along a second axial direction of the distillation unit (1) under the action of a pressure difference, and the second axial direction is opposite to the first axial direction.

3. The device according to claim 2, characterized in that The microtube (2) comprises a gas-liquid phase exchange section. When the gas in the external space and the liquid in the liquid phase channel (200) flow, heat and mass transfer are performed in the gas-liquid phase exchange section of the microtube (2) through the gas-liquid phase exchange holes, so that the heavy component gas in the external space is converted into liquid and enters the liquid phase channel (200), and the light component liquid in the liquid phase channel (200) is converted into gas and enters the external space, and separation and purification are achieved by repeated reciprocation.

4. The device according to claim 1, characterized in that During the distillation process, the plurality of microtubes (2) are placed horizontally or tilted, and the first end (11) of the distillation unit (1) and the second end (12) of the distillation unit are at substantially the same height level or at different height levels.

5. The device according to claim 4, characterized in that The plurality of microtubes (2) are stacked together to form a cylinder, and the distance between the centers of two adjacent microtubes (2) is within the range of 1 mm to 2 mm.

6. The device according to claim 5, characterized in that The pore diameter of the gas-liquid phase exchange hole (21) is in the range of 0.02 mm to 0.05 mm.

7. The device according to claim 6, characterized in that The gas-liquid phase exchange holes (21) are evenly arranged in the circumferential direction and the axial direction of the microtube.

8. The device according to claim 1, characterized in that The capillary force should be greater than or equal to the gas-liquid phase pressure difference, which refers to the difference between the static pressure head of the liquid in the liquid phase channel (200) and the static pressure head of the gas flowing in the external space outside the microtube (2).

9. The device according to claim 1, characterized in that The device also includes a condenser and a reboiler, wherein the condenser is located at the second end of the distillation unit and is configured to condense the heavy component gas or heavy isotopes in the ultra-high purity gas or isotopes to be distilled in a gaseous state into a liquid, and the reboiler is located at the first end of the distillation unit and is configured to heat the light component gas or light isotopes in the ultra-high purity gas or isotopes to be distilled in a liquid state into a gas.

10. A cascade system for ultra-high purity gas or isotope separation based on capillary force drive, characterized in that: The system comprises one or more devices for ultra-high purity gas or isotope separation based on capillary force drive according to any one of claims 1 to 9 connected in series.

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