A rectification column for producing anhydrous hydrogen fluoride from low-grade fluorite

Abstract

The utility model relates to a kind of rectifying column of low-grade fluorite preparation anhydrous hydrogen fluoride.The rectifying column of low-grade fluorite preparation anhydrous hydrogen fluoride includes tower body, tower body is equipped with tray, tray includes plate body, plate body upper side is equipped with overflow plate, plate body between two overflow plates is equipped with steam passage, plate body is equipped with downcomer, steam passage is equipped with steam pipe, plate body upper side is equipped with cover cap covering steam pipe upper side, cover cap is equipped with steam outlet, the inboard of cover cap is equipped with adjusting ring, plate body is equipped with the guide rod moving up and down, the upper end of guide rod is fixedly connected with adjusting ring, the lower end of guide rod extends plate body lower side and is fixedly connected with push plate, and reset spring is equipped between guide rod and plate body lower side face.The utility model can increase the steam area of steam outlet when steam pressure rises, thereby relieving steam pressure rise, avoid the evaporation temperature rise caused by steam pressure rise, and increase the indirect contact between steam and hydrofluoric acid, improve rectification efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of distillation column technology, specifically relating to a distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite. Background Technology

[0002] Electronic-grade hydrofluoric acid, a representative wet electronic chemical, is one of the key basic chemical materials in the integrated circuit manufacturing process, mainly used in chip cleaning, etching, and other steps. The purity and cleanliness of electronic-grade hydrofluoric acid have a significant impact on the yield, electrical performance, and reliability of integrated circuits.

[0003] Fluorite is currently the most important mineral resource for fluorochemical production and the most crucial source of hydrofluoric acid. Its quality and reserves are key factors influencing the development of the fluorochemical industry. Due to the massive scale of domestic fluoride, especially fluoride salt, production facilities, the demand for high-quality fluorite is enormous. After a long period of large-scale mining, high-quality fluorite resources have been largely depleted, leading to increasingly tight supply. While China still possesses abundant low-grade fluorite resources, the production of anhydrous hydrogen fluoride from low-grade fluorite is receiving increasing attention.

[0004] Chinese utility model patent CN221955830U discloses a fluorite-based hydrofluoric acid production reactor. Low-grade fluorite, sulfur trioxide, and water vapor are used in this reactor to generate industrial hydrofluoric acid. The industrial hydrofluoric acid is then used to prepare anhydrous hydrofluoric acid using a distillation column. A distillation column is a tower-type vapor-liquid contact device that separates vapor and liquid by utilizing the flow of liquid and the rise of vapor. In existing technologies, the tray structure within a distillation column is simple. During distillation, due to the different layer distribution of the trays, the rising vapor pressure on each layer is unstable. Increased vapor pressure easily leads to increased evaporation temperature on the trays, affecting the distillation quality and requiring repeated evaporation, thus reducing distillation efficiency. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite.

[0006] The technical solution of this utility model for a distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite is as follows:

[0007] A distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite includes a column body with several trays arranged sequentially from top to bottom. Each tray includes a plate body, and two parallel, spaced-apart overflow plates are provided on the upper side of the plate body. Several steam vents are provided on the plate body between the two overflow plates. A downcomer is provided on one side of one of the overflow plates on the plate body. The downcomers of two adjacent trays are located on both sides of the column body. A steam pipe is provided in each steam vent. A cap is provided on the upper side of the plate body covering the steam pipe. The cap has a steam outlet. An adjusting ring is provided on the inner side of the cap, which slides and seals with the inner wall of the cap to adjust the size of the steam outlet. A guide rod that moves up and down is provided on the plate body. The upper end of the guide rod is fixedly connected to the adjusting ring, and the lower end of the guide rod extends out of the lower side of the plate body and is fixedly connected to a push plate. A return spring is provided between the guide rod and the lower side of the plate body.

[0008] Furthermore, the cap includes a conical section and a cylindrical section integrally formed on the lower side of the conical section. The upper end of the conical section is sealed, and there are several steam outlet holes arranged circumferentially on the cylindrical section.

[0009] Furthermore, both the upper and lower ends of the steam pipe are flared structures, the steam pipe is coaxially arranged with the cap, the inner wall of the adjusting ring is provided with a fixing block, the upper end of the guide rod is fixedly connected to the fixing plate, and the lower side of the push plate is a concave arc surface.

[0010] Furthermore, the lower end of the downcomer of the tray abuts against the overflow plate of the tray below, and the downcomer is provided with several guide plates.

[0011] Furthermore, the top of the tower body is provided with a steam outlet pipe, the bottom of the tower body is provided with a liquid outlet pipe, the lower side of the tower body is provided with a steam inlet pipe, the middle part of the tower body is provided with a liquid inlet pipe, and the upper side of the tower body is provided with a return liquid pipe. The steam outlet pipe is connected to the steam inlet of the cooler through a first connecting pipe, and the return liquid pipe is connected to the liquid outlet of the condenser through a second connecting pipe. A discharge pipe is connected to the second connecting pipe through a three-way connector, and a shut-off valve is provided on the discharge pipe.

[0012] Furthermore, a reflux steam pipe is provided on the lower side of the tower body, the liquid outlet pipe is connected to the liquid inlet of the reboiler through a third connecting pipe, and the reflux steam pipe is connected to the steam outlet of the reboiler through a fourth connecting pipe.

[0013] This invention provides a distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite. Compared with existing technologies, its advantages are:

[0014] In the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite, the hydrofluoric acid to be distilled enters the corresponding tray inside the column through the inlet pipe, and the liquid flows downwards along the trays. High-temperature steam enters from the bottom of the distillation column. Since the trays inside the column are distributed layer by layer from top to bottom, the steam pressure on the upper and lower trays is inconsistent, and the high-temperature steam pressure fluctuates continuously due to various factors. When the steam pressure increases, the rising steam pressure overcomes the spring force of the reset spring and the weight of the adjusting ring, guide rod, and push plate. The push plate, guide rod, and adjusting ring move upwards, reducing the portion of the adjusting ring blocking the steam outlet, thereby increasing the steam outlet area, alleviating the rise in steam pressure, and increasing the contact between steam and hydrofluoric acid. Compared to existing technologies, this invention can alleviate the rise in steam pressure by increasing the steam outlet area, avoiding the increase in evaporation temperature caused by the rise in steam pressure, and increasing the contact between steam and hydrofluoric acid, thus improving distillation efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to this utility model.

[0016] Figure 2 This is a schematic diagram of the structure of the tray in the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to this utility model.

[0017] Figure 3 This is a schematic diagram of the structure of the steam vent hole on the tray in the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to this utility model.

[0018] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0019] Figure 5 This is a schematic diagram of the internal structure of the downcomer in the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to this utility model.

[0020] In the diagram: 1. Tower body; 2. Steam outlet pipe; 3. Liquid outlet pipe; 4. Liquid inlet pipe; 5. Steam inlet pipe; 6. Reflux liquid pipe; 7. Reflux steam pipe; 8. Tower plate; 81. Plate body; 82. Overflow plate; 83. Steam vent; 84. Downcomer; 841. Outlet; 842. Guide plate; 9. Steam vent pipe; 10. Cap; 11. Steam outlet; 12. Adjusting ring; 13. Fixing block; 14. Guide rod; 15. Push plate; 16. Return spring; 17. Condenser; 18. First connecting pipe; 19. Second connecting pipe; 20. Discharge pipe; 21. Shut-off valve; 22. Reboiler; 23. Third connecting pipe; 24. Fourth connecting pipe. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0022] Specific embodiments of the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to this utility model are as follows: Figures 1 to 5 As shown, the structure includes a tower body 1, which has a cylindrical structure and a conical structure at both the top and bottom. Several tower plates 8 are connected inside the tower body 1, arranged sequentially from top to bottom, with the tower plates 8 evenly spaced in the vertical direction of the tower body 1.

[0023] In this embodiment, the tray 8 includes a tray body 81. Two overflow plates 82 arranged in parallel and spaced apart are fixedly connected to the upper side of the tray body 81. Several vertical steam vents 83 are provided on the tray body 81 between the two overflow plates 82, penetrating both ends of the tray body 81. The steam vents 83 are arranged in multiple rows, with the rows of steam vents 83 arranged in parallel and spaced apart on the tray body 81. The spacing between adjacent steam vents 83 in each row is equal.

[0024] A mounting hole is provided on one side of one of the overflow plates 82, penetrating both ends of the plate 81. A downcomer 84 is welded into the mounting hole. The outer surface of the downcomer 84 is a vertically extending inferior arc surface, and the inner surface is a vertically extending plane. The lower side of the downcomer 84 has an outlet 841 facing the center of the tower body 1. In two adjacent tower plates 8, the lower end of the downcomer 84 of the upper tower plate 8 abuts against the overflow plate 82 of the lower tower plate 8. The downcomer 84 of the upper tower plate 8 and the downcomer 84 of the lower tower plate 8 are located on opposite sides of the tower body 1. To reduce liquid splashing from the downcomer 84 of the upper tower plate 8 onto the lower tower plate 8, several guide plates 842 are fixedly connected inside the downcomer 84. The guide plates 842 extend obliquely downwards.

[0025] In this embodiment, a steam pipe 9 is fixedly connected to each steam vent hole 83 of the tower plate 8. The upper end of the steam pipe 9 extends to the upper side of the plate body 81, and the lower end of the steam pipe 9 extends to the lower side of the plate body 81. A cover 10 is fixedly connected to the outer side of each steam pipe 9 on the upper side of the plate body 81. The cover 10 includes a conical section and a cylindrical section integrally formed on the lower side of the conical section. The upper end of the conical section is sealed, and a plurality of steam outlet holes 11 are opened on the outer wall of the cylindrical section. The plurality of steam outlet holes 11 are arranged circumferentially on the cylindrical section.

[0026] The inner side of the cap 10 has an adjusting ring 12 that slides and seals with the inner wall of the cap 10 for adjusting the size of the steam outlet 11. The adjusting ring 12 is located above the steam outlet 11. A guide rod 14 that moves up and down is mounted on the plate 81. The upper end of the guide rod 14 is fixedly connected to the adjusting ring 12, and the lower end of the guide rod 14 extends out of the lower side of the plate 81 and is fixedly connected to a push plate 15. A return spring 16 is provided between the guide rod 14 and the lower side of the plate 81.

[0027] In this embodiment, both the upper and lower ends of the steam pipe 9 are flared structures. The steam pipe 9 and the cap 10 are arranged coaxially. The inner wall of the adjusting ring 12 is provided with a fixing block 13. The upper end of the guide rod 14 is fixedly connected to the fixing plate. The lower side of the push plate 15 is a concave arc surface. The top of the tower body 1 is fixedly connected to the steam outlet pipe 2, the bottom of the tower body 1 is fixedly connected to the liquid outlet pipe 3, the lower side of the tower body 1 is fixedly connected to the steam inlet pipe 5, the middle part of the tower body 1 is fixedly connected to the liquid inlet pipe 4, and the upper side of the tower body 1 is fixedly connected to the return liquid pipe 6. The steam outlet pipe 2 is connected to the steam inlet of the cooler through the first connecting pipe 18. The return liquid pipe 6 is connected to the liquid outlet of the condenser 17 through the second connecting pipe 19. The second connecting pipe 19 is connected to the discharge pipe 20 through a three-way connector. The discharge pipe 20 is fixedly connected to the shut-off valve 21.

[0028] In this embodiment, a reflux steam pipe 7 is fixedly connected to the lower side of the tower body 1, the liquid outlet pipe 3 is connected to the liquid inlet of the reboiler 22 through the third connecting pipe 23, and the reflux steam pipe 7 is connected to the steam outlet of the reboiler 22 through the fourth connecting pipe 24.

[0029] In the distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite of this invention, the hydrofluoric acid to be distilled enters the corresponding tray 8 inside the column body 1 through the inlet pipe 4, and the liquid flows downwards along the tray 8. High-temperature steam enters through the bottom of the distillation column. Since the trays 8 inside the distillation column are distributed layer by layer from top to bottom, the steam pressure on the upper and lower trays 8 is inconsistent, and the high-temperature steam pressure is constantly changing due to various factors. When the steam pressure increases, the rising steam pressure breaks through the elastic force of the reset spring 16 and the gravity of the adjusting ring, guide rod 14, and push plate 15. The push plate 15, guide rod 14, and adjusting ring move upwards, reducing the portion of the adjusting ring blocking the steam outlet 11, thereby increasing the steam outlet area of ​​the steam outlet 11, alleviating the rise in steam pressure, and increasing the contact between the steam and the hydrofluoric acid. Compared with the prior art, this invention can alleviate the rise in steam pressure by increasing the steam outlet area of ​​the steam outlet 11, thus avoiding the rise in evaporation temperature caused by the rise in steam pressure. It also increases the contact between steam and hydrofluoric acid, thereby improving the distillation efficiency.

[0030] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite, characterized in that, The system includes a tower body, which contains several tower plates arranged sequentially from top to bottom. Each tower plate includes a plate body. Two overflow plates are arranged in parallel and spaced intervals on the upper side of the plate body. Several steam vents are provided on the plate body between the two overflow plates. A downcomer is located on one side of one of the overflow plates on the plate body. The downcomers of two adjacent tower plates are located on opposite sides of the tower body. A steam pipe is installed inside each steam vent. A cap is provided on the upper side of the plate body, covering the steam pipe. The cap has a steam outlet. An adjusting ring is provided on the inner side of the cap, slidingly sealing against the inner wall of the cap to adjust the size of the steam outlet. A guide rod that moves up and down is provided on the plate body. The upper end of the guide rod is fixedly connected to the adjusting ring, and the lower end of the guide rod extends out from the lower side of the plate body and is fixedly connected to a push plate. A return spring is provided between the guide rod and the lower side of the plate body.

2. The distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to claim 1, characterized in that, The cap includes a conical section and a cylindrical section integrally formed on the lower side of the conical section. The upper end of the conical section is sealed. There are several steam outlet holes, which are arranged circumferentially on the cylindrical section.

3. The distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to claim 2, characterized in that, Both ends of the steam pipe are flared, the steam pipe is coaxial with the cap, the inner wall of the adjusting ring is provided with a fixing block, the upper end of the guide rod is fixedly connected to the fixing plate, and the lower side of the push plate is a concave arc surface.

4. The distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to claim 1, characterized in that, The lower end of the downcomer of the tray abuts against the overflow plate of the tray below, and the downcomer is provided with several guide plates.

5. The distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to claim 1, characterized in that, The top of the tower body is provided with a steam outlet pipe, the bottom of the tower body is provided with a liquid outlet pipe, the lower side of the tower body is provided with a steam inlet pipe, the middle part of the tower body is provided with a liquid inlet pipe, and the upper side of the tower body is provided with a return liquid pipe. The steam outlet pipe is connected to the steam inlet of the condenser through a first connecting pipe, and the return liquid pipe is connected to the liquid outlet of the condenser through a second connecting pipe. The second connecting pipe is connected to a discharge pipe through a three-way connector, and a shut-off valve is provided on the discharge pipe.

6. The distillation column for producing anhydrous hydrogen fluoride from low-grade fluorite according to claim 5, characterized in that, The lower side of the tower body is provided with a reflux steam pipe, the liquid outlet pipe is connected to the liquid inlet of the reboiler through a third connecting pipe, and the reflux steam pipe is connected to the steam outlet of the reboiler through a fourth connecting pipe.

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