A distillation apparatus for a sublimable substance

Abstract

The utility model discloses an easy sublimation material's distillation device, include: material kettle, inside is provided with stirring subassembly, is provided with heating subassembly outside, receive kettle, inside is provided with condensation component, is provided with spray subassembly at the top, is provided with cooling subassembly outside, wherein, material kettle top communicates with the spray subassembly of receiving kettle top through the distillation bend, and the material kettle in the sublimation material enters the receiving kettle and condenses the collection through the distillation bend. The utility model discloses open -type material tank and kettle cover are connected through flange, and the isomer condensed on the inner wall can be washed to the bottom with cooling liquid by the continuous spraying of spray head, and the solid easy sublimation material condenses to the filter bag, and the solvent is formed even liquid membrane through the filler layer and support board, effectively reduces the surface tension, so that the liquid can flow out smoothly, and does not appear the siltation of the whole device operation simple, effectively improved the intermediate purity, avoided the material loss while convenient experimental instrument cleaning.

Description

Technical Field

[0001] This utility model relates to the technical field of laboratory distillation apparatus, specifically to a distillation apparatus for easily sublimable substances. Background Technology

[0002] Sublimable substances are those that can directly transform from a solid to a gaseous state (i.e., undergo a sublimation physical change) under normal temperature and pressure or relatively low temperature conditions without going through a liquid stage. These substances have weak intermolecular forces, and in the solid state, molecules do not need to absorb a large amount of heat to break through the liquid's binding force; they can directly detach from the solid surface and enter the gaseous state. Currently, the most commonly used purification method in industry is recrystallization, which requires a series of complex operations such as yield loss, solvent recovery, and mother liquor reuse. The yield is easily lost due to solute residue and mother liquor waste, resulting in high overall cost and process complexity. Research has found that easily sublimable substances can be removed using steam distillation. This allows the easily sublimable substances to be carried into the condenser along with the steam. Due to the presence of high-temperature steam in the condenser, the solubility of the easily sublimable substances increases, ensuring the entire pipeline remains unobstructed. This method avoids recrystallization, filtration, and mother liquor recovery operations.

[0003] However, in practice, it was found that the existing distillation apparatus could cause blockages at the receiving port or in the condenser. Therefore, the distillation process had to be paused periodically for unblocking. This directly led to frequent interruptions of the distillation process, which should have been continuous. This not only disrupted the continuity of the heating, condensation, and collection stages, but also repeatedly disrupted the experimental rhythm, significantly extending the overall experimental time. In addition, the unblocking process required frequent disassembly of apparatus parts and the use of solvents to rinse and scrape off the blockages, which was time-consuming and caused material loss, affecting the stability of the product yield and reducing the reproducibility of the experiment. Utility Model Content

[0004] The purpose of this invention is to provide a distillation apparatus for easily sublimated substances in order to solve the above problems.

[0005] To achieve the above objectives, this utility model specifically adopts the following technical solution, including: The material container is equipped with an internal stirring assembly and an external heating assembly; The receiving vessel is equipped with a sublimation assembly inside, a spray assembly on top, and a cooling assembly on the outside. The top of the material vessel is connected to the spray assembly at the top of the receiving vessel via a distillation bend, and the sublimated substance in the material vessel enters the receiving vessel through the distillation bend for condensation and collection.

[0006] As a further description of the above technical solution, the top of the material vessel is provided with a positioning port, a feeding port is provided on one side of the positioning port, a first temperature port is provided on one side of the feeding port, and a distillation port is provided on the other side of the positioning port.

[0007] As a further description of the above technical solution, the stirring assembly includes a stirring paddle, and the stirring rod connected to the stirring paddle passes through the positioning port and is rotatably connected to the stirring motor.

[0008] As a further description of the above technical solution, the heating assembly includes a heating jacket, a first medium inlet is provided at the bottom of one side of the heating jacket, and a first medium outlet is provided at the top of the other side of the heating jacket.

[0009] As a further description of the above technical solution, the receiving vessel is provided with a connection interface at the top, a second temperature port is provided on one side of the connection interface, and a discharge port is provided at the bottom of the receiving vessel.

[0010] As a further description of the above technical solution, the deposition assembly includes a support plate, a packing layer is disposed above the support plate, a filter bag is disposed above the packing layer, the edge of the filter bag is in contact with the inner wall of the receiving vessel, and the height of the filter bag is higher than the flange sealing surface of the receiving vessel.

[0011] As a further description of the above technical solution, the spraying assembly includes a spraying tower, a spraying head is provided inside the spraying tower, an vent is provided at the top of the spraying tower, a spraying port is provided at the top of one side of the spraying tower, and a feed inlet is provided at the bottom of the other side of the spraying tower.

[0012] As a further description of the above technical solution, the spray head is connected to the transfer pump via a spray port through a pipe, and the transfer pump is connected to the receiving vessel via a feed port through a pipe.

[0013] As a further description of the above technical solution, the cooling assembly includes a cooling jacket, a second medium inlet is provided at the bottom of one side of the cooling jacket, and a second medium outlet is provided at the top of the other side of the cooling jacket.

[0014] As a further description of the above technical solution, the distillation bend is connected to the distillation port of the material vessel and the feed port of the receiving vessel respectively, and a third temperature port is provided at the top of the distillation bend.

[0015] The beneficial effects of this utility model are as follows: In this invention, the open-type material tank and the lid are connected by a flange. The spray head continuously sprays coolant, which can wash the isomers condensed on the inner wall to the bottom. Solid easily sublimable substances are sublimated into the filter bag, while the solvent forms a uniform liquid film through the packing layer and support plate, effectively reducing the surface tension and allowing the liquid to flow out smoothly without clogging. The whole device is easy to operate, effectively improves the purity of intermediates, avoids material loss, and facilitates the cleaning of experimental equipment.

[0016] To more clearly illustrate the structural features and functions of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the distillation apparatus for easily sublimable substances according to this utility model; Figure 2 for Figure 1 Schematic diagram of the middle support plate; Figure 3 Here is the HPLC chromatogram of the reaction solution; Figure 4 This is an HPLC chromatogram after steam distillation; Figure 5 The 1H NMR spectrum of 5-hydroxy-3-trifluoromethyl-1-methyl-1H-pyrazole; Figure 6 The 1H NMR spectrum of the isomer 3-hydroxy-5-trifluoromethyl-1-methyl-1H-pyrazole; Figure 7 DSC chromatogram of 5-hydroxy-3-trifluoromethyl-1-methyl-1H-pyrazole; Figure 8 The image shows the DSC diagram of the isomer 3-hydroxy-5-trifluoromethyl-1-methyl-1H-pyrazole.

[0018] Figure label: 1. Material vessel; 11. Positioning port; 12. Feeding port; 13. First temperature port; 14. Distillation port; 2. Stirring assembly; 21. Stirring paddle; 22. Stirring motor; 3. Heating assembly; 31. Heating jacket; 32. First medium inlet; 33. First medium outlet; 4. Receiving vessel; 41. Connecting port; 42. Second temperature port; 43. Discharge port; 5. Sublimation assembly; 51. Support plate; 52. Packing layer; 53. Filter bag; 6. Spray assembly; 61. Spray tower; 62. Spray head; 63. Vent port; 64. Spray nozzle; 65. Feed inlet; 7. Cooling assembly; 71. Cooling jacket; 72. Second medium inlet; 73. Second medium outlet; 8. Distillation bend; 81. Third temperature port. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0020] like Figures 1-2 As shown, in one embodiment, a distillation apparatus for an easily sublimable substance includes: a material vessel 1 and a receiving vessel 4; Among them, material tank 1 and receiving tank 4 are both open tanks, and the top of the tank is sealed by a flange after being fitted with a tank cover. This not only facilitates the filling of materials in the early stage and the cleaning and maintenance of the equipment in the later stage, but also allows for flexible adaptation to internal components of different specifications. Furthermore, the flange surface of the connection between the vessel lid and the vessel body is finely ground and fastened with metal clamps, which can effectively improve the fit of the sealing surface. Combined with the uniform fastening of high-strength metal clamps, it can effectively prevent the leakage of gaseous substances during the distillation process, ensuring stable internal pressure and material recovery rate of the device.

[0021] It should be explained in detail that the material vessel 1 is equipped with a stirring component 2 for stirring the material. By continuously turning the material, it avoids the material from coking or uneven sublimation caused by local overheating, and at the same time accelerates the heat exchange between the material and the vessel wall. The external part is equipped with a heating component 3 for heating the vessel body, which provides a stable and controllable heating environment for the material. Correspondingly, the receiving vessel 4 is equipped with a deposition component 5 for deposition intermediates, a spray component 6 for spraying coolant on the top, and a cooling component 7 for cooling vessel body on the outside, so as to realize the rapid condensation and separation of gaseous substances. In addition, the top of the material vessel 1 is connected to the spray assembly 6 at the top of the receiving vessel 4 via the distillation bend 8, which can guide the gaseous substances generated by sublimation in the material vessel 1 to smoothly enter the receiving vessel 4 through a preset path to complete the condensation collection.

[0022] It should be noted that the distillation bend 8 is connected to the distillation port 14 of the material vessel 1 and the feed port 65 of the receiving vessel 4 respectively. A third temperature port 81 is provided at the top of the distillation bend 8, which can monitor the gas phase temperature in real time and help the operator judge the sublimation rate.

[0023] Specifically, the distillation bend 8 adopts a straight distillation bend 8 with a vacuum jacket. The vacuum jacket utilizes the low thermal conductivity of the vacuum environment to achieve efficient heat preservation, eliminating the need for additional insulation materials such as asbestos. This simplifies the device structure and avoids the shedding of contaminants from traditional insulation materials. The straight design reduces the flow resistance of gaseous substances. Combined with the heat preservation effect of the vacuum jacket, it can effectively prevent easily sublimable substances from prematurely condensing due to temperature drop during transmission, thus avoiding the problem of bend blockage at the source.

[0024] For example, please continue reading Figure 1The material vessel 1 is provided with a positioning port 11 at the top for positioning and installing the stirring component 2; a feeding port 12 is provided on one side of the positioning port 11 for convenient batch addition of raw materials; a first temperature port 13 is provided on one side of the feeding port 12 for monitoring the temperature inside the material vessel 1; a distillation port 14 is provided on the other side of the positioning port 11 for discharging the sublimated gas.

[0025] Furthermore, the stirring assembly 2 includes a stirring paddle 21, which is rotatably connected to an external stirring motor 22 via a vertically extending stirring rod. The stirring rod passes through the positioning port 11 at the top of the material container 1, and a sealed bearing is installed at the connection point to ensure stable rotation of the stirring rod and prevent leakage of gaseous substances inside the container.

[0026] Specifically, the material of the agitator 21 can be selected according to the characteristics of the material: if the material is highly corrosive, polytetrafluoroethylene (PTFE) with excellent chemical stability can be selected; if it needs to withstand high temperature or high intensity stirring, stainless steel or other metal materials can be selected. Correspondingly, the form of the agitator 21 can also be flexibly adapted to different material states: the frame agitator 21 is suitable for all-round stirring of high viscosity materials, the propeller agitator 21 is suitable for rapid mixing of low viscosity materials, the turbine agitator 21 can produce a strong radial mixing effect, and the anchor agitator 21 can fit against the bottom of the vessel to prevent material deposition.

[0027] Furthermore, the heating assembly 3 includes a heating jacket 31, with a first medium inlet 32 ​​at the bottom of one side of the heating jacket 31 and a first medium outlet 33 at the top of the other side of the heating jacket 31, to ensure that the heating medium (such as heat transfer oil) can fill the entire jacket space and achieve stable heat transfer through continuous circulation.

[0028] For example, please continue reading Figure 1 The receiving vessel 4 is provided with a docking interface 41 at the top for docking and installing the spray assembly 6; a second temperature port 42 is provided on one side of the docking interface 41 for monitoring the temperature inside the receiving vessel 4; and a discharge port 43 is provided at the bottom of the receiving vessel 4, which is equipped with a liquid feed valve to control the inflow and outflow of liquid.

[0029] Furthermore, the deposition component 5 includes a support plate 51, a packing layer 52 is laid on the support plate 51, and a filter bag 53 is disposed on the packing layer 52.

[0030] Specifically, the support plate 51 is a glass-perforated support plate 51. The glass material has strong chemical stability and is not easy to react with materials. The evenly distributed holes can support the packing layer 52 and filter bag 53 above, and also ensure that the liquid passes through smoothly. Correspondingly, the packing layer 52 is made of spring packing or ring packing, which increases the surface area so that the flowing liquid forms a uniform liquid film and improves the gas-liquid contact efficiency. In addition, the filter bag 53 covers the packing layer 52, and its mesh size can be selected between 50 mesh and 400 mesh (fine mesh is suitable for collecting small crystals, and coarse mesh is suitable for large particles). Elastic materials such as silicone can be added around the filter bag 53. Through elastic deformation, the edge of the filter bag 53 can be completely fitted with the inner wall of the receiving vessel 4 to prevent the condensed material from leaking out from the gaps. At the same time, the height of the filter bag 53 is designed to be 0.5cm to 1cm higher than the flange sealing surface of the receiving vessel 4. This detail can avoid friction damage to the filter bag 53 at the flange connection and ensure that the collected solid material is completely retained inside the filter bag 53.

[0031] Furthermore, the spray assembly 6 includes a spray tower 61, inside which a spray head 62 is provided, and at the top of the spray tower 61 is a vent 63. On one side of the top of the spray tower 61, a spray port 64 is provided to discharge the uncondensed gas during the distillation process and to balance the pressure inside and outside the device. On the other side of the bottom of the spray tower 61, a feed port 65 is provided.

[0032] It should be explained in detail that the spray head 62 is connected to the transfer pump through the spray port 64, and the transfer pump is connected to the receiving vessel 4 through the inlet 65, thereby realizing the continuous spraying of coolant.

[0033] Specifically, the material of the connecting pipes can be selected according to the characteristics of the material: polytetrafluoroethylene is suitable for corrosive materials, glass is convenient for observing the liquid flow, and metal is suitable for high pressure or high temperature environments.

[0034] Furthermore, the cooling assembly 7 includes a cooling jacket 71, with a second medium inlet 72 at the bottom of one side of the cooling jacket 71 and a second medium outlet 73 at the top of the other side of the cooling jacket 71, to ensure that the cooling medium (such as cooling water) can fill the jacket and carry away the heat in the receiving vessel 4 through continuous circulation, thereby maintaining the low-temperature environment required for sublimation.

[0035] Working principle: The top of the material vessel 1 is connected to the distillation bend 8, the other end of the distillation bend 8 is connected to the spray assembly 6, and the bottom of the spray assembly 6 is connected to the top of the receiving vessel 4. The raw material is added to the material vessel 1 through the feeding port 12 at the top of the material vessel 1. Then, the stirring motor 22 is turned on to drive the stirring paddle 21 to rotate and stir the material. The external heating circulation device connected to the heating jacket 31 of the material vessel 1 is turned on, so that the heating medium (e.g., heat transfer oil) flows into the heating jacket 31 from the first medium inlet 32 ​​and flows out of the heating jacket 31 from the first medium outlet 33. The temperature of the material vessel 1 is monitored through the first temperature port 13. At the same time, the external cooling circulation device connected to the cooling jacket 71 of the receiving vessel 4 makes the cooling medium (e.g., cooling water) flow into the cooling jacket 71 from the second medium inlet 72 and flow out of the cooling jacket 71 from the second medium outlet 73. The temperature of the receiving vessel 4 is monitored through the second temperature port 42. Then the transfer pump is started. As heating continues, the easily sublimable substance flows from the distillation port 14 through the distillation bend 8 and into the spray tower 61 through the feed port 65. At the same time, the gas phase temperature can be monitored in real time through the third temperature port 81. When the gaseous easily sublimable substance enters the spray tower 61, the spray head 62 continuously sprays cooling water, causing the gaseous easily sublimable substance to quickly condense and fall into the filter bag 53 above the packing layer 52.

[0036] If solvent is entrained during the sublimation process, the solvent can flow through the packing layer 52 and the support plate 51 to the outlet 43. Since the packing layer 52 is added between the filter bag 53 and the glass-perforated support plate 51, the liquid can form a uniform liquid film in the packing layer 52, which effectively reduces the surface tension of the liquid and allows the liquid to flow out smoothly through the glass holes on the support plate 51, avoiding the problem of blockage. Furthermore, since the distance between the feed inlet 65 and the spray head 62 is relatively far, the easily sublimable substance can be cooled and crystallized to the maximum extent. In the case of solvent entrainment, a small amount of easily sublimable substance at the condensation interface can be flushed away by local reflux, thereby keeping the device unobstructed. Other uncondensed gases during the distillation process can be discharged through the vent 63.

[0037] The separation of the product from easily sublimable substances is essentially the removal of easily sublimable impurities by steam distillation. During the steam distillation process, depending on the content of impurities, water can be added while distilling in actual operation to ensure that easily sublimable substances are removed as much as possible. When the liquid level inside the receiving vessel 4 reaches three-quarters of the receiving tank volume, the feed valve at the discharge port 43 needs to be opened to release the solvent until the liquid level reaches the top of the packing layer 52. Then the feed valve is closed again to continue the distillation operation. After distillation, open the metal clamp at the flange of the receiving vessel 4 and remove the filter bag 53 to obtain a high-purity solid sublimable substance.

[0038] It should be noted that this device is only suitable for separating products from easily sublimable substances in the presence of liquid. Essentially, it removes easily sublimable impurities through liquid (steam) distillation. During the steam distillation process, depending on the impurity content, in actual operation, water can be added while distilling to ensure the removal of easily sublimable substances.

[0039] For example, when using the distillation apparatus of this application to remove isomers generated during the synthesis of the sulfonylpyrazol intermediate 5-hydroxy-3-trifluoromethyl-1-methyl-1H-pyrazole, after removing the mixture of ethanol and water by atmospheric distillation, the isomers can be removed by steam distillation. The isomers are carried into the condenser with the steam. Due to the presence of high-temperature steam in the condenser, the solubility of the isomers increases, so it is necessary to ensure proper insulation of the pipelines. The temperature inside the distillation vessel is 100~115℃. After cooling in the receiving vessel, the isomers precipitate in the water. The entire process can be completely reproduced in the laboratory with good reproducibility. The isomer content can be reduced from the original 8% to below 1%, eliminating the need for complicated operations such as filtration and recrystallization. In actual operation, the spray assembly installed in the receiving vessel can wash the isomers condensed on the wall into the receiving vessel with water. The entire process of the apparatus has important reference value for industrial design. The combination of filter bags and open-type reaction vessels in the receiving vessel is also for the convenience of laboratory operation and cleaning of glass instruments.

[0040] Please continue reading. Figure 3 The figure shows the HPLC chromatogram of the reaction solution. As can be seen from the figure, the product peak is at retention time 12.4 min, and the isomer peak is at retention time 12.7 min. The figure also shows that the isomer content in the reaction solution before distillation is normalized to 8.68%. Please continue reading. Figure 4 The figure shows the HPLC chromatogram after steam distillation. As can be seen, the product peak is at retention time 12.4 min, and the isomer peak is at retention time 12.7 min. The figure also shows that the isomer content in the reaction solution after distillation is normalized to 0.38%.

[0041] Please continue reading. Figure 5 The figure shows the 1H NMR spectrum of 5-hydroxy-3-trifluoromethyl-1-methyl-1H-pyrazole. As can be seen from the figure, 1 HNMR (400MHz, CDCl3): 5.76 (s, 1H), 3.73 (s, 3H).

[0042] Please continue reading. Figure 6 The figure shows the 1H NMR spectrum of the isomer 3-hydroxy-5-trifluoromethyl-1-methyl-1H-pyrazole. As can be seen from the figure, 1 HNMR (400MHz, CDCl3): δ11.23 (s, 1H), 5.98 (s, 1H), 3.80 (s, 3H); Please continue reading. Figure 7 The image shows the DSC chromatogram of 5-hydroxy-3-trifluoromethyl-1-methyl-1H-pyrazole. As can be seen from the image, the product has no sublimation peak and the initial melting temperature is 176.22℃. Please continue reading. Figure 8The figure shows the DSC chromatogram of the isomer 3-hydroxy-5-trifluoromethyl-1-methyl-1H-pyrazole. As can be seen from the figure, the isomer exhibits significantly different properties from the product. The isomer has a sublimation onset temperature of 88.54℃ and an initial melting temperature of 123.88℃. We utilized this significant difference to effectively separate the product from the isomer.

[0043] After separation and purification using the above technical solution, the product purity was effectively improved, as shown in the table below: Table 1. Purity of products before and after distillation at different temperatures.

[0044] Through the above technical solution, the open material tank and the lid of this application are connected by a flange. The spray head 62 continuously sprays coolant, which can wash the isomers condensed on the inner wall to the bottom. Solid easily sublimable substances are sublimated into the filter bag 53, while the solvent forms a uniform liquid film through the packing layer 52 and the support plate 51, which effectively reduces the surface tension and allows the liquid to flow out smoothly without clogging. The whole device is easy to operate, effectively improves the purity of intermediates, avoids material loss and facilitates the cleaning of experimental equipment.

[0045] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distillation apparatus for easily sublimable substances, characterized in that, include: The material container is equipped with an internal stirring assembly and an external heating assembly; The receiving vessel is equipped with a sublimation assembly inside, a spray assembly on top, and a cooling assembly on the outside. The top of the material vessel is connected to the spray assembly at the top of the receiving vessel via a distillation bend, and the sublimated substances in the material vessel enter the receiving vessel through the distillation bend for condensation and collection.

2. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The material vessel is provided with a positioning port at the top, a feeding port is provided on one side of the positioning port, a first temperature port is provided on one side of the feeding port, and a distillation port is provided on the other side of the positioning port.

3. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The stirring assembly includes a stirring paddle, and the stirring rod connected to the stirring paddle passes through the positioning port and is rotatably connected to the stirring motor.

4. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The heating assembly includes a heating jacket, with a first medium inlet at the bottom of one side of the heating jacket and a second medium outlet at the top of the other side of the heating jacket.

5. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The receiving vessel is provided with a connection port at the top, a second temperature port on one side of the connection port, and a discharge port at the bottom of the receiving vessel.

6. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The deposition assembly includes a support plate, a packing layer is disposed above the support plate, a filter bag is disposed above the packing layer, the edge of the filter bag is in contact with the inner wall of the receiving vessel, and the height of the filter bag is higher than the flange sealing surface of the receiving vessel.

7. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The spraying assembly includes a spraying tower, which is equipped with spraying heads inside. The top of the spraying tower is equipped with an vent, and the top of one side of the spraying tower is equipped with a spraying port, while the bottom of the other side of the spraying tower is equipped with a feed inlet.

8. The distillation apparatus for easily sublimable substances according to claim 7, characterized in that, The spray head is connected to the transfer pump via a spray port pipe, and the transfer pump is connected to the receiving vessel via a feed port pipe.

9. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The cooling assembly includes a cooling jacket, with a second medium inlet at the bottom of one side of the cooling jacket and a second medium outlet at the top of the other side of the cooling jacket.

10. The distillation apparatus for easily sublimable substances according to claim 1, characterized in that, The distillation bend is connected to the distillation port of the material vessel and the feed port of the receiving vessel, respectively, and a third temperature port is provided at the top of the distillation bend.

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