Filler for boron isotope separation and low-temperature rectifying tower

Abstract

The invention provides filler for boron isotope separation and a low-temperature rectifying tower, and relates to the technical field of isotope separation. The filler for boron isotope separation comprises the connecting line and the multiple filler monomers connected to the connecting line in series, the distance between every two adjacent filler monomers is 1-10 mm, the hydraulic diameter of each filler monomer is 2-20 mm, and the filler is suitable for an isotope separation system which is low in treatment capacity and requires small gas phase resistance; the filler has ultra-low pressure drop and excellent liquid self-distribution performance, the separation efficiency of boron trifluoride isotope low-temperature rectification can be improved, the filler is used in a low-temperature rectification tower, mounting and dismounting are convenient, blockage is not prone to occurring, cleaning is convenient, the strength requirement can be met, and the production cost is reduced. The filler has obvious pressure drop advantage, has the advantages of difficulty in blockage and low construction cost, can reduce the height of the low-temperature rectifying tower for boron isotope separation, and overcomes the problem of small separation capacity of a small-diameter tower.

Description

Technical Field

[0001] The present application relates to the technical field of isotope separation, and in particular to a filler and a cryogenic distillation tower for boron isotope separation. Background Art

[0002] Boron is present in abundances of 19.78% and 80.22% respectively. 10 B and 11 B exists in nature in the form of isotopes. Among them, 10 B has a strong ability to absorb thermal neutrons and is widely used in modern industry, biomedicine and other technical fields; 11 B is an important raw material in the production of high-tech products such as chips.

[0003] There are many methods for enriching boron isotopes, such as boron trifluoride chemical exchange distillation, cryogenic distillation, ion exchange chromatography, laser separation, and adsorption separation. However, due to the great difficulty of industrial production of boron isotope enrichment, many methods are still in the laboratory exploration stage. So far, the boron trifluoride chemical exchange distillation process with anisole as the main complexing agent has truly achieved industrial production of boron isotope separation. However, the process flow is relatively complicated, the operation requires high precision, and moisture in the distillation process is difficult to avoid, resulting in the cracked boron fluoride reacting with water to form highly corrosive hydrofluoric acid, which causes serious corrosion to equipment and pipelines and poses safety problems. With the advancement of automatic control and cryogenic refrigeration technology, this process is gradually being replaced by cryogenic distillation production processes.

[0004] Cryogenic distillation utilizes the slight difference in boiling points between isotope atoms or molecules to separate light and heavy components through multiple vapor-liquid exchange equilibrium on the surface of the filler. The separation coefficient of isotope cryogenic distillation is low. 10 B isotope is treated by cryogenic distillation BF 3 , at normal boiling point, the separation coefficient in the distillation tower is only 1.0076. Therefore, if you want to enrich a higher abundance 10 For isotope B, thousands of theoretical plates are needed. According to the wire mesh structured packing (7 theoretical plates per meter) widely used in industry today, the separation tower packing needs to be more than 200 meters long. However, the isotope production scale is relatively small, the reflux ratio is large, and the liquid flow rate in the tower is small, resulting in a distillation tower diameter of only tens of millimeters. The system separation is difficult, the pressure drop is high, and the engineering and civil construction investment is huge, making it difficult to ensure the separation efficiency of the distillation tower. Summary of the invention

[0005] The purpose of the present application is to provide a filler and a cryogenic distillation tower for boron isotope separation, aiming to solve the problems of the prior art cryogenic distillation device being too high, having a small tower diameter, having a high pressure drop, having a low processing capacity, and having a large engineering investment.

[0006] To achieve the above objectives, the present application provides a filler for boron isotope separation, comprising a connecting line and a plurality of filler monomers connected in series on the connecting line; the distance between the filler monomers is 1 mm to 10 mm; and the hydraulic diameter of the filler monomer is 2 mm to 20 mm.

[0007] In some embodiments, the connecting wire is a steel wire or a nylon wire; the material of the filler monomer is stainless steel, copper, aluminum or its oxides and alloys; the filler monomer is trapezoidal or conical.

[0008] The present application also provides a cryogenic distillation tower for boron isotope separation, comprising a tower body composed of a plurality of tower sections, a condenser disposed at the top of the tower body, and a reboiler disposed at the bottom of the tower body;

[0009] A plurality of fillers for boron isotope separation as described above are arranged in each tower section, and the plurality of fillers for boron isotope separation are vertically suspended in the tower section.

[0010] In some embodiments, the number of the fillers for boron isotope separation in each of the tower sections is 30 to 80;

[0011] The plurality of fillers for boron isotope separation are evenly distributed in the tower section, and the distance between the plurality of fillers for boron isotope separation is 5 mm to 25 mm.

[0012] In some embodiments, the pressure drop of the plurality of fillers for boron isotope separation in each of the tower sections is 1 Pa / m to 300 Pa / m.

[0013] In some embodiments, the surface area of ​​the plurality of fillers for boron isotope separation in each of the tower sections is 80 m 2 / m 3 ~600m 2 / m 3 .

[0014] In some embodiments, a liquid distribution device is provided at the top of the tower section, and the liquid distribution device includes a downcomer provided corresponding to each of the fillers for boron isotope separation;

[0015] A supporting and fixing device is provided at the bottom of the tower section to fix the filler for boron isotope separation.

[0016] In some embodiments, the supporting and fixing device includes a drainage hole arranged corresponding to each filler for boron isotope separation; and a long strip-shaped gas channel is arranged on the side of the supporting and fixing device.

[0017] In some embodiments, a liquid collecting and redistributing device is provided between adjacent tower sections. The liquid collecting and redistributing device is provided below the supporting and fixing device and is connected to the drainage hole and the liquid distributing device.

[0018] In some embodiments, a liquid spray device is disposed on the top of the tower body, and the liquid spray device is connected to the condenser; and a protective layer is disposed on the outer surface of the low-temperature distillation tower for boron isotope separation.

[0019] Compared with the prior art, the beneficial effects of this application include:

[0020] The filler for boron isotope separation provided in the present application includes a connecting line and a plurality of filler monomers connected in series on the connecting line, the distance between the filler monomers is 1 mm to 10 mm, and the hydraulic diameter of the filler monomers is 2 mm to 20 mm. The filler of the present application is suitable for isotope separation systems with low processing volume and requiring small gas phase resistance. It has ultra-low pressure drop and excellent liquid self-distribution performance, and can improve the separation efficiency of low-temperature distillation of boron trifluoride isotopes. The filler of the present application is easy to install and disassemble when used in a low-temperature distillation tower, is not easy to clog, and is easy to clean, can meet strength requirements, and reduce production costs.

[0021] The low-temperature distillation tower for boron isotope separation provided in the present application adopts the filler of the present application. Compared with the traditional metal corrugated structured filler, the vertical filler has obvious advantages in filler pressure drop, and also has the advantages of not being easy to clog and having low construction cost. It can reduce the tower height of the low-temperature distillation tower for boron isotope separation and overcome the problem of small separation capacity of small-diameter tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0023] Figure 1 This is a schematic diagram of the overall structure of a cryogenic distillation tower for boron isotope separation in the present application;

[0024] Figure 2 A cross-sectional view of a tower body of a cryogenic distillation tower for boron isotope separation according to the present application;

[0025] Figure 3 A schematic diagram of an arrangement of fillers for boron isotope separation in the present application;

[0026] Figure 4 This is a schematic diagram of another arrangement of fillers for boron isotope separation in the present application.

[0027] Reference numerals:

[0028] 1000-cryogenic distillation tower for boron isotope separation; 100-tower body; 110-tower section; 10-filler for boron isotope separation; 12-connecting line; 14-filler monomer; 120-liquid distribution device; 122-downhole; 130-supporting and fixing device; 140-liquid collecting and redistributing device; 150-liquid spraying device; 200-condenser; 300-reboiler. DETAILED DESCRIPTION

[0029] As used herein:

[0030] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0031] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0032] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0033] In these examples, parts and percentages are by mass unless otherwise indicated.

[0034] The present application provides a filler 10 for boron isotope separation, see Figure 2, including a connecting line 12 and a plurality of filler monomers 14 connected in series on the connecting line 12; the distance between the filler monomers 14 is 1 mm to 10 mm; and the hydraulic diameter of the filler monomers 14 is 2 mm to 20 mm.

[0035] The filler 10 for boron isotope separation of the present application is in the range of 12 mm to 100 mm according to the diameter of the boron trifluoride low-temperature distillation tower in actual engineering, the hydraulic diameter of the filler monomer 14 is 2 mm to 20 mm, and the vertical spacing between adjacent filler monomers 14 is preferably maintained at 1 mm to 10 mm, so as to overcome the disadvantage of small diameter tower with small production capacity and meet the needs of industrial-scale production.

[0036] The hydraulic diameter refers to four times the ratio of the flow cross-sectional area to the circumference. Since the wall shear stress of a non-circular tube is not uniformly distributed along the four sides, only the average value along the four sides can be calculated. Comparing the expressions of the two cases, we can get an intuitive analogy, that is, A / P~r / 2. Multiplying both sides by 4, we have 4A / P~2r(=D). In this way, the hydraulic diameter and the true diameter of the circular tube are equivalent in the hydraulic sense.

[0037] The hydraulic diameter is introduced in the flow in the pipe in order to obtain a suitable characteristic length for the non-circular pipe flow to calculate its Reynolds number. For non-circular pipes, since the wall shear stress along the four sides is not uniformly distributed, only the average value along the four sides can be calculated. When calculating the Reynolds number, the diameter of the circular pipe is obviously taken as the characteristic length, so 4A / P can also be used as the characteristic length of the non-circular pipe, which is called the "hydraulic diameter".

[0038] In the present application, the liquid flows through the surface of the filler monomer 14, which plays a role similar to that of a non-circular tube, so the hydraulic diameter of the filler monomer 14 is the same as the hydraulic diameter of the non-circular tube.

[0039] The filler of the present application is suitable for isotope separation systems with low processing volume and requiring small gas phase resistance. It has ultra-low pressure drop and excellent liquid self-distribution performance, and can improve the separation efficiency of low-temperature distillation of boron trifluoride isotopes. The filler of the present application is easy to install and disassemble when used in a low-temperature distillation tower, is not easy to clog and is easy to clean, can meet strength requirements, and reduce production costs.

[0040] Among them, multiple filler monomers 14 are evenly distributed, and the distance between the filler monomers 14 is 1mm to 10mm, for example, it can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between 1mm and 10mm. The filler monomers 14 are arranged within this suitable range, so that each filler monomer 14 can be loaded with a certain liquid, ensuring uniform distribution of gas and liquid, and having abundant gas-liquid contact area, thereby meeting the separation requirements. If the distance between the filler monomers 14 is too small, too many filler monomers 14 need to be arranged, and too many filler monomers 14 cause the connecting line 12 to bear too much weight, and the filler 10 used for boron isotope separation may swing, and the filler 10 used for boron isotope separation is unstable and has an adverse effect on gas-liquid contact. If the distance between the filler monomers 14 is too large, too few filler monomers 14 are arranged, and too few filler monomers 14 provide few channels for liquid flow, resulting in insufficient gas-liquid contact and poor heat and mass transfer effects.

[0041] Among them, the hydraulic diameter of the filler monomer 14 is 2mm to 20mm, for example, it can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm or any value between 2mm and 20mm. The size of the filler monomer 14 needs to be controlled within a reasonable range according to the size of the tower section 110 and the connecting line 12 and the amount of liquid flow in the tower. If the filler monomer 14 is too large or too small, it will have an adverse effect on heat transfer and mass transfer. If the filler monomer 14 is too large, the channel size for gas phase flow is reduced, resulting in an increase in gas resistance, and the filler manufacturing cost is also significantly increased. If the filler monomer 14 is too small, the filler specific surface area is too small, the gas-liquid distribution is poor, and the mass transfer efficiency is reduced.

[0042] In some embodiments, the filler monomer 14 is provided with through holes passing through the upper and lower ends thereof, and the connecting wire 12 is fixed by passing through the through holes on the filler monomer 14. In other embodiments, the filler monomer 14 can also be fixed to the connecting wire 12 by bonding.

[0043] In some embodiments, the connecting wire 12 is a steel wire or a nylon wire; the material of the filler monomer 14 is stainless steel, copper, aluminum or its oxides and alloys; the filler monomer 14 is trapezoidal or conical.

[0044] The present application also provides a cryogenic distillation tower 1000 for boron isotope separation, see Figure 1 and Figure 2, comprising a tower body 100 consisting of a plurality of tower sections 110, a condenser 200 arranged at the top of the tower body 100, and a reboiler 300 arranged at the bottom of the tower body 100; a plurality of fillers 10 for boron isotope separation as described above are arranged in each of the tower sections 110, and the plurality of fillers 10 for boron isotope separation are vertically suspended in the tower section 110.

[0045] The low-temperature distillation tower 1000 for boron isotope separation provided in the present application adopts the filler of the present application. Compared with the traditional metal corrugated structured filler, the vertical filler has obvious advantages in filler pressure drop, and also has the advantages of not being easy to clog and having low construction cost. It can reduce the tower height of the low-temperature distillation tower 1000 for boron isotope separation and overcome the problem of small separation capacity of small-diameter towers.

[0046] In some embodiments, the number of the fillers 10 for boron isotope separation in each of the tower sections 110 is 30 to 80, for example, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 or any value between 30 and 80. If the number of the fillers 10 for boron isotope separation is lower than the range, the separation effect of the cryogenic distillation tower 1000 for boron isotope separation is poor, and if the number of the fillers 10 for boron isotope separation is higher than the range, the cost is too high.

[0047] In some embodiments, the plurality of fillers 10 for boron isotope separation are uniformly distributed in the tower section 110 to improve the heat and mass transfer of the gas-liquid two-phases, and the distance between the plurality of fillers 10 for boron isotope separation is 5 mm to 25 mm, for example, it can be 5 mm, 6 mm, 7 mm, 8 mm, 10 mm, 12 mm, 15 mm, 17 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 25 mm or any value between 5 mm and 25 mm.

[0048] In some embodiments, see Figure 3 and Figure 4 The plurality of fillers 10 for boron isotope separation can be uniformly distributed in the tower section 110 in various shapes, such as in the shape of an equilateral triangle ( Figure 4 ) or square ( Figure 3 ) are evenly arranged in the tower section 110.

[0049] In some embodiments, the central axis of the filler 10 for boron isotope separation is perpendicular to the horizontal plane, and the central axes of multiple fillers 10 for boron isotope separation are parallel to achieve the best filling effect and ensure mass transfer efficiency.

[0050] In some embodiments, the pressure drop of the plurality of fillers 10 for boron isotope separation in each tower section 110 is 1 Pa / m to 300 Pa / m, for example, 1 Pa / m, 10 Pa / m, 20 Pa / m, 30 Pa / m, 40 Pa / m, 50 Pa / m, 60 Pa / m, 70 Pa / m, 80 Pa / m, 90 Pa / m, 100 Pa / m, 110 Pa / m, 120 Pa / m, 130 Pa / m. m, 140Pa / m, 150Pa / m, 160Pa / m, 170Pa / m, 180Pa / m, 190Pa / m, 200Pa / m, 210Pa / m, 220Pa / m, 230Pa / m, 240Pa / m, 250Pa / m, 260Pa / m, 270Pa / m, 280Pa / m, 290Pa / m, 300Pa / m or any value between 1Pa / m and 300Pa / m.

[0051] Pressure drop is caused by the collision and exchange of momentum between fluid particles when the fluid flows and overcomes internal friction and turbulence, which is manifested as a pressure difference before and after the fluid flows. The magnitude of the pressure drop changes with the flow rate in the pipe. The pressure drop range is the pressure drop with the gas phase load (0-3Pa 0.5 ) range of variation. Under the same gas phase load, compared with the traditional metal wire mesh corrugated structured packing, the filler 10 for boron isotope separation of the present application has a lower pressure drop, that is, a lower gas phase resistance, which greatly reduces energy consumption and saves operating costs.

[0052] In some embodiments, the surface area of ​​the plurality of fillers 10 for boron isotope separation in each tower section 110 is 80 m 2 / m 3 ~600m 2 / m 3 , for example, it can be 80m 2 / m 3 、100m 2 / m 3 、120m 2 / m 3 、150m 2 / m 3 、170m 2 / m 3 、200m 2 / m 3 、230m 2 / m 3 、250m 2 / m 3 、280m 2 / m 3 、300m 2 / m 3 、350m2 / m 3 、400m 2 / m 3 、450m 2 / m 3 、500m 2 / m 3 、550m 2 / m 3 、600m 2 / m 3 or 80m 2 / m 3 ~600m 2 / m 3 Compared with conventional fillers, the filler 10 for boron isotope separation of the present application has a competitive effective mass transfer area and a high mass transfer efficiency.

[0053] In some embodiments, see Figure 2 The top of the tower section 110 is provided with a liquid distribution device 120, and the liquid distribution device 120 includes a downcomer 122 corresponding to each of the fillers 10 for boron isotope separation. The top reflux liquid can be evenly distributed to each of the fillers 10 for boron isotope separation through the liquid distribution device 120 and the downcomer 122, so that multiple fillers 10 for boron isotope separation can obtain liquid with the same and stable flow rate.

[0054] In some embodiments, see Figure 2 A supporting and fixing device 130 is provided at the bottom of the tower section 110 to ensure the free droop of the filler 10 for boron isotope separation and the unchanged spacing between the filler monomers 14, thereby preventing the filler 10 for boron isotope separation from swinging and entanglement with each other, and playing a role in fixing and limiting the filler 10 for boron isotope separation.

[0055] In some embodiments, the supporting and fixing device 130 includes a drainage hole (not shown in the figure) arranged corresponding to each of the fillers 10 for boron isotope separation, which plays the role of fixing the connecting line 12 and draining the liquid, and the size of the drainage hole is 2mm~10mm; a long gas channel (not shown in the figure) is arranged on the side of the supporting and fixing device 130, and the diameter size of the hole arranged in the gas channel can be set to 5mm~20mm, and the hole size of the gas channel is slightly larger than the size of the drainage hole.

[0056] In some embodiments, please refer to Figure 2A liquid collecting and redistributing device 140 is provided between adjacent tower sections 110. The liquid collecting and redistributing device 140 is provided below the supporting and fixing device 130 and is connected with the drainage hole and the liquid distributing device 120. A liquid collecting and redistributing device 140 is provided between adjacent tower sections 110 to redistribute the gas-liquid two-phase in the tower, thereby ensuring the heat and mass transfer of the gas-liquid two-phase.

[0057] Specifically, the liquid collecting and redistributing device 140 is arranged below the supporting and fixing device 130 of the previous tower section 110 and above the liquid distributing device 120 of the adjacent next tower section 110, and is used to collect the liquid flowing out of the drainage hole of the supporting and fixing device 130 of the previous tower section 110, and send the liquid to the liquid distributing device 120 of the next tower section 110, so as to ensure that the liquid in each tower section 110 can be evenly distributed on each filler 10 for boron isotope separation.

[0058] In some embodiments, see Figure 1 and Figure 2 The top of the tower body 100 is provided with a liquid spraying device 150, and the liquid spraying device 150 is connected to the condenser 200. The tower top reflux liquid flowing out of the condenser 200 is sprayed to the liquid distribution device 120 in the first tower section 110 through the liquid spraying device 150, and is drained to the downcomer 122 of each packing correspondingly provided on the liquid distribution device 120, so that the liquid can be evenly distributed to each packing.

[0059] In some embodiments, the outer surface of the cryogenic distillation tower 1000 for boron isotope separation is provided with a protective layer (not shown in the figure), and the protective layer has heat insulation and corrosion protection functions.

[0060] In some embodiments, the cryogenic distillation tower 1000 for boron isotope separation of the present application further includes a refrigeration cycle device, a raw material inlet pipeline, a product extraction pipeline and a collection system.

[0061] In some embodiments, the function of the reboiler 300 is to heat the kettle liquid of the low-temperature distillation tower 1000 for boron isotope separation to boiling, provide a certain flow of rising steam, and at the same time, part of the kettle liquid is produced as the tower bottom product; the function of the condenser 200 is to condense the rising steam entering the top of the low-temperature distillation tower 1000 for boron isotope separation, and part of the condensate flows into the tower as reflux liquid, and part of it is produced as the tower top product.

[0062] The refrigeration cycle device of the condenser 200 can use liquid nitrogen as a refrigerant to provide condensation BF 3 The cooling capacity required by the gas is achieved by gasifying the liquid nitrogen and then liquefying it for recycling. 3 , in raw materials11 BF 3 and 10 BF 3 The molar purities of the two derivatives were 19.78% and 80.22%, respectively.

[0063] The separation process of the cryogenic distillation tower 1000 for boron isotope separation of the present application is as follows: the raw material natural abundance boron trifluoride gas enters the middle and lower part of the cryogenic distillation tower, the gas rises to the top of the tower, is condensed into liquid by the top liquid nitrogen condenser 200, and then flows to the bottom reboiler 300, the bottom reboiler 300 provides heat to vaporize the boron trifluoride, so that the gas passes from bottom to top through the external vertical space of the filler 10 for boron isotope separation, and contacts the descending boron trifluoride liquid film attached to the filler 10 for boron isotope separation in reverse direction and undergoes heat and mass transfer process to achieve the separation of boron trifluoride isotopes. Finally, the enriched boron 10 isotope can be extracted from the bottom of the tower, and the enriched boron 11 isotope can be extracted from the top of the tower.

[0064] Taking the actual engineering boron trifluoride cryogenic distillation tower with 1600 working plates as an example, according to the metal wire mesh corrugated packing (theoretical plate number is 7 pieces / meter) widely used in engineering today, the packing filling height is 228 meters, plus the height occupied by the liquid distribution and recollection device, the tower top and the tower bottom, the total height of the cryogenic distillation tower using the existing packing must reach at least 296 meters. However, using the ultra-low pressure drop vertical packing of the present application, at a packing density of 0.7m 3 / m 3 , the number of theoretical plates can reach 60 to 80 per meter, and the required distillation tower packing height is 26.7 meters. Considering the height occupied by the liquid distribution and recollection device and the tower top and bottom, the total height of the low-temperature distillation tower for boron isotope separation in this application is at least 34.7 meters. Compared with traditional structured packing, the height of the isotope distillation tower is reduced by 261.3 meters, which greatly reduces the investment in engineering civil construction, saves costs, and reduces the difficulty of equipment manufacturing.

[0065] The filler 10 for boron isotope separation of the present application is the main place for gas-liquid heat and mass transfer of boron trifluoride isotopes. Liquid falling into the gap between the fillers can form a liquid bridge due to the effect of surface tension, and the inner and outer sides of the liquid bridge are exposed to the gas environment. Therefore, the liquid bridge is the main place for gas-liquid heat and mass transfer. During low-temperature distillation operation, the liquid flows downward along the vertical filler channel in the form of a liquid bridge, and the gas contacts the liquid film in reverse from bottom to top through the vertical channels inside and outside the filler and undergoes a heat and mass transfer process. The filler can maintain an extremely low wet tower pressure drop under different gas phase loads. Compared with traditional metal corrugated regular fillers, the filler 10 for boron isotope separation of the present application has an obvious pressure drop advantage. In addition, the vertical filler has excellent liquid self-distribution ability, and the liquid phase channel can increase the contact time between gas and liquid.

[0066] In summary, the ultra-low pressure drop vertical packing for boron isotope separation of the present application is suitable for distillation separation with a small diameter tower and a small processing capacity. It can not only reduce the gas-liquid phase resistance, but also facilitate the uniform distribution of gas and liquid, and at the same time improve the mass transfer effect of the packing. The vertical packing has a simple structure, convenient installation, and high mass transfer efficiency. It overcomes the problem of small separation capacity of small diameter towers, and can greatly reduce the height of low-temperature distillation towers, save costs, and reduce the difficulty of equipment manufacturing. Compared with traditional structured packing, the pressure drop is greatly reduced, and the liquid is evenly distributed, without wall flow, channel flow and other phenomena, eliminating the disadvantages of traditional structured packing.

[0067] The cryogenic distillation tower 1000 for boron isotope separation of the present application can achieve ultra-long period and ultra-long stable operation, and can continuously produce high-abundance boron isotope products, fully meeting the basic requirements of isotope separation. Compared with the traditional chemical exchange method, the cryogenic distillation method for enriching boron isotopes has a single separation material, normal pressure operation, low energy consumption, fast production rate, simple process operation, relatively simple control method, cost saving, and reduced equipment manufacturing difficulty. In addition, the cryogenic distillation process does not have the problem of material decomposition and corrosion of equipment. The production capacity of the same scale of production equipment is larger than that of other processes.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0069] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A filler for boron isotope separation, characterized in that: It comprises a connecting line and a plurality of filler monomers connected in series on the connecting line; the distance between the filler monomers is 1 mm to 10 mm; and the hydraulic diameter of the filler monomers is 2 mm to 20 mm.

2. The filler for boron isotope separation according to claim 1, characterized in that: The connecting wire is a steel wire or a nylon wire; the material of the filler monomer is stainless steel, copper, aluminum or its oxide and alloy; the filler monomer is trapezoidal or conical.

3. A cryogenic distillation tower for boron isotope separation, characterized in that: It comprises a tower body composed of a plurality of tower sections, a condenser arranged at the top of the tower body and a reboiler arranged at the bottom of the tower body; A plurality of fillers for boron isotope separation as claimed in claim 1 or 2 are arranged in each tower section, and the plurality of fillers for boron isotope separation are vertically suspended in the tower section.

4. The cryogenic distillation tower for boron isotope separation according to claim 3, characterized in that: The number of the fillers for boron isotope separation in each tower section is 30 to 80; The plurality of fillers for boron isotope separation are evenly distributed in the tower section, and the distance between the plurality of fillers for boron isotope separation is 5 mm to 25 mm.

5. The cryogenic distillation tower for boron isotope separation according to claim 3, characterized in that: The pressure drop of the multiple fillers for boron isotope separation in each tower section is 1Pa / m to 300Pa / m.

6. The cryogenic distillation tower for boron isotope separation according to claim 3, characterized in that: The surface area of ​​the plurality of fillers for boron isotope separation in each tower section is 80 m 2 / m 3 ~600m 2 / m 3 .

7. The cryogenic distillation tower for boron isotope separation according to any one of claims 3 to 6, characterized in that: A liquid distribution device is provided at the top of the tower section, and the liquid distribution device includes a downcomer provided corresponding to each of the fillers for boron isotope separation; A supporting and fixing device is provided at the bottom of the tower section to fix the filler for boron isotope separation.

8. The cryogenic distillation tower for boron isotope separation according to claim 7, characterized in that: The supporting and fixing device comprises a drainage hole arranged corresponding to each filler for boron isotope separation; and a long strip-shaped gas channel is arranged on the side of the supporting and fixing device.

9. The cryogenic distillation tower for boron isotope separation according to claim 8, characterized in that: A liquid collecting and redistributing device is arranged between adjacent tower sections. The liquid collecting and redistributing device is arranged below the supporting and fixing device and is connected with the drainage hole and the liquid distributing device.

10. The cryogenic distillation tower for boron isotope separation according to claim 9, characterized in that: A liquid spray device is arranged on the top of the tower body, and the liquid spray device is connected to the condenser; and a protective layer is arranged on the outer surface of the low-temperature distillation tower for boron isotope separation.

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