Continuous evaporation desublimation purification system
By using a continuous evaporation-sublimation purification system, which employs staged sublimation and a rotary drum sublimator to separate light and heavy impurities, the problems of solvent residue, low purity, and low yield in ODA production have been solved. This has enabled efficient and stable ODA production, improved purity and yield, and simplified the process flow.
Patent Information
- Application Number
- CN202422942649.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-11-29
AI Technical Summary
Existing ODA production suffers from problems such as solvent residue, low purity, low yield, low efficiency, and high labor intensity. In particular, commercially available sublimed materials have large particles that are difficult to dissolve, the cooling crystallization method has low yield and a wide particle size distribution, and the mother liquor from the dissolution crystallization method is difficult to recover.
A continuous evaporation-sublimation purification system is adopted, including a melting device, a first-stage sublimator, a second-stage sublimator, a third-stage sublimator, a first-stage condenser, a second-stage condenser unit, and a third-stage condenser. Light and heavy impurities are separated through staged condensation and rotary drum condensers, avoiding the addition of solvent. Buffer chambers are used to regulate airflow and collect crystalline substances, realizing multi-stage series condensation to improve efficiency and purity.
It has enabled the production of high-purity ODA, simplified the production process, reduced the risk of environmental pollution, improved production efficiency and yield, reduced energy consumption for solvent recovery, adjustable product particle size, high equipment operating stability, and increased production capacity.
Smart Images
Figure CN223464455U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the fine chemical separation purification technical field, concretely relates to a continuous evaporation condensation purification system. BACKGROUND
[0002] 4,4-diaminodiphenyl ether (4,4-diaminodiphenyl ether or 4,4-oxydianiline) is abbreviated as DADPE or ODA, which is a high value-added fine chemical intermediate and is widely used in the synthesis of polyimide, poly-maleimide and other heat-resistant plastics.
[0003] At present, the ODA sold on the market mainly has two forms of sublimation and crystallization. Among them, the sublimation material on the market has large particles (5-10 centimeters in diameter), which is not convenient for the dissolution of the material in the later stage, resulting in the need for long-time stirring and dissolution after feeding, affecting the production efficiency. In addition, if the material is not fully dissolved, it will also cause low product yield.
[0004] The ODA crystallization process mainly includes cooling crystallization method and solvent-out crystallization method. The cooling crystallization method usually uses anhydrous dimethylformamide (DMF) or anhydrous methanol as a solvent, and forms a supersaturated solution by cooling to make ODA crystals precipitate. However, the yield of the cooling crystallization method is low, and the product crystal particle size is small and the particle size distribution is wide, which is difficult to filter, wash and dry, and is not convenient for subsequent processing and use. In addition, the cooling crystallization process is prone to wall sticking, which makes the crystallization process difficult to control and easy to aggregate during long-term storage.
[0005] The solvent-out crystallization method uses anhydrous dimethylformamide (DMF) as a solvent and water as a solvent-out agent. Water is added dropwise in the system to rapidly reduce the solubility of ODA in the DMF water mixed solvent, forming a supersaturated solution, so that the crystals precipitate. The ODA product obtained by the solvent-out crystallization method has high yield, but the mother liquor is a mixture of water and dimethylformamide, and ordinary rectification method is difficult to realize the recovery of dimethylformamide.
[0006] In view of the above problems, it is of great significance to seek an ODA refining method with high purity, high efficiency and high yield. UTILITY MODEL CONTENT
[0007] The utility model intends to provide a continuous evaporation condensation purification system to solve the problems of solvent residue, low purity, low yield, low efficiency and high labor intensity in the prior art. In order to achieve the above purpose, the utility model adopts the following technical scheme:
[0008] The continuous evaporation and condensation purification system comprises a melting device, a first sublimator, a second sublimator, a third sublimator, a first condenser, a second condenser unit and a third condenser, the melting device is communicated with the feeding port of the first sublimator, the discharging port of the first sublimator is communicated with the feeding port of the second sublimator, the gas outlet of the first sublimator is communicated with the gas inlet of the first condenser, the discharging port of the second sublimator is communicated with the feeding port of the third sublimator, the gas outlet of the second sublimator is communicated with the second condenser unit, and the gas outlet of the third sublimator is communicated with the gas inlet of the third condenser.
[0009] Preferably, as an improvement, the second condenser unit comprises a product condenser and a tail gas condenser, and the gas outlet of the product condenser is communicated with the gas inlet of the tail gas condenser.
[0010] Preferably, as an improvement, the product condenser comprises a front product condenser and a rear product condenser, the gas outlet of the front product condenser is communicated with the gas inlet of the rear product condenser, and the gas outlet of the rear product condenser is communicated with the gas inlet of the tail gas condenser.
[0011] Preferably, as an improvement, the discharging port of the tail gas condenser and the discharging port of the third condenser are both communicated with the feeding port of the melting device.
[0012] Preferably, as an improvement, the second sublimator and the second condenser unit are both provided as two groups and the two groups are simultaneously operated.
[0013] Preferably, as an improvement, the discharging port of the first condenser is communicated with a light component buffer bin, the light component buffer bin is communicated with a light component receiving bin, and the gas outlet of the first condenser is communicated with a vacuum device.
[0014] Preferably, as an improvement, the discharging port of the front product condenser is communicated with a product front buffer bin, the product front buffer bin is communicated with a product front receiving bin, the discharging port of the rear product condenser is communicated with a product rear buffer bin, the product rear buffer bin is communicated with a product rear receiving bin, the discharging port of the tail gas condenser is communicated with a tail gas condensation buffer bin, the tail gas condensation buffer bin is communicated with a tail gas condensation receiving bin, the tail gas condensation receiving bin is communicated with the feeding port of the melting device, and the gas outlet of the tail gas condenser is also communicated with a vacuum device.
[0015] Preferably, as an improvement, the discharging port of the third condenser is communicated with a recycled product buffer bin, the recycled product buffer bin is communicated with a recycled product receiving bin, the recycled product receiving bin is communicated with the feeding port of the melting device, and the gas outlet of the first condenser is also communicated with a vacuum device.
[0016] Preferably, as an improvement, the first condenser, the second condenser unit and the third condenser are all rotary drum condensers.
[0017] The principle and beneficial effects of the scheme are:
[0018] 1. The products produced by this scheme are of high purity: ODA contains light impurities and heavy impurities during sublimation. The first-stage sublimator + first-stage desublimator is mainly used to remove light impurities and obtain products containing light impurities; the second-stage sublimator + second-stage desublimator unit is mainly used to separate products; the third-stage sublimator + third-stage desublimator is mainly used to extract residual products containing heavy impurities. This scheme adopts graded desublimation (setting up a first-stage desublimator, a second-stage desublimator unit and a third-stage desublimator, the first-stage desublimator collects products containing front impurities, the second-stage desublimator unit collects high-content products, and the third-stage desublimator collects products containing heavy impurities), which can achieve effective separation of light and heavy impurities, and the obtained products are of high purity. At the same time, the front-stage products containing light impurities and the back-stage products containing heavy impurities can be applied back to the first-stage sublimator, and the recycling yield is high.
[0019] 2. No solvent is introduced: This solution adopts the sublimation-desublimation method. No additional solvent is required during the purification process, which avoids solvent contamination of the product and reduces energy consumption and cost during the solvent recovery process. This not only improves the purity of the product, but also simplifies the production process and reduces the risk of environmental pollution.
[0020] 3. Using a rotary drum desublimator for desublimation, a scraper promptly scrapes off the desublimated solids, solving the problem of desublimation crystals hindering desublimation heat transfer and significantly improving desublimation efficiency. This allows for the conversion of gas into solid products. During the desublimation process, the desublimation temperature and time of the desublimator can be adjusted to control the product's grain size, allowing for products in different forms (such as powder, flakes of varying thickness, and products of varying densities, etc.), truly achieving adjustable product particle size and controllable surface morphology.
[0021] 4. This solution uses continuous sublimation and desublimation, which can continuously discharge materials, improve production capacity, and has a short sublimation cycle, replacing the traditional intermittent sublimation process (the products obtained by the traditional intermittent sublimation process are black and white, and manual scraping and screening of white products are required, which is inefficient and labor-intensive).
[0022] 5. This solution sets a buffer tank at each stage of the desublimator, whose main function is to regulate and stabilize the airflow and collect the crystallized material separated from the sublimation process. The specific functions are as follows:
[0023] A. Airflow Regulation: The buffer chamber balances the flow rate of the sublimation gas, ensuring even distribution of the gas as it passes through the desublimator. Stable airflow helps improve the efficiency of the crystallization process and avoids uneven distribution of the crystallized material due to unstable airflow.
[0024] B. Collecting Crystalline Substances: During sublimation, the substances in the gas can condense into solids upon cooling. One of the functions of the buffer tank is to provide a space to collect these condensed crystalline substances. Through the function of the buffer tank, the crystalline substances will not be directly discharged from the equipment and can be collected and guided out at the appropriate location.
[0025] C. Preventing Crystalline Substances from Returning: The buffer tank can prevent the condensed substances from being carried back to the sublimation area due to changes in airflow, which helps to improve the purity and crystallization efficiency of the product.
[0026] D. Regulating Pressure: The buffer tank also functions to regulate the internal gas pressure. By controlling the pressure, the buffer tank can help maintain the balance of the sublimation and condensation processes, ensuring the normal operation of the equipment.
[0027] 6. In this scheme, the secondary condensation unit is designed with three condensers. Through the multi-stage series connection, the condensation efficiency can be effectively improved. In addition, the design of multiple condensers can improve the redundancy of the system. Even if one condenser fails, the others can still work, ensuring the continuity and stability of the production process. The multi-stage condenser design can also distribute the cooling load of each condenser, avoiding the high load of a single condenser, thereby improving the operation stability of the equipment and prolonging the service life of the equipment. Each condenser has a smaller working load and can cool more evenly, preventing uneven crystallization or excessive cooling rate caused by excessive cooling. In the design of multi-stage condensers, the temperature of the front-stage condenser is higher, which can effectively recover heat to provide a temperature difference for the rear-stage condenser. This can reduce the demand for cooling agents and energy consumption, improving the energy utilization efficiency of the entire system.
[0028] 7. In this scheme, the secondary sublimator and the secondary condensation unit are designed with two production lines running simultaneously, which has the following effects:
[0029] A. Improve production capacity and efficiency: Two production lines can handle more materials simultaneously, thereby improving overall production capacity and output and shortening production cycles.
[0030] B. Increase equipment utilization: Dual production lines can share equipment load, reduce downtime, and ensure efficient operation of the equipment.
[0031] C. Parallel processing: Sublimation and condensation processes can be performed simultaneously, avoiding waiting time and improving production efficiency.
[0032] D. Improve stability: If one production line fails, the other can continue to operate, avoiding production downtime.
[0033] E. Flexible adjustment: The material flow and processing method of each production line can be adjusted as needed, improving production flexibility.
[0034] F. Optimize resource usage: The two production lines can better allocate energy and cooling resources, reduce waste and improve energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 This is a structural diagram of an embodiment of the present utility model. DETAILED DESCRIPTION
[0036] The following is further described in detail through specific implementation methods:
[0037] The figure marks in the drawings of the specification include: first-stage sublimator 1, second-stage sublimator 2, third-stage sublimator 3, first-stage condenser 4, front-stage product condenser 5, rear-stage product condenser 6, tail gas condenser 7, third-stage condenser 8, light component buffer bin 9, light component receiving bin 10, vacuum device 11, product front buffer bin 13, product front receiving bin 14, product rear buffer bin 15, product rear receiving bin 16, tail gas condenser buffer bin 17, tail gas condenser receiving bin 18, recovered product buffer bin 19, recovered product receiving bin 20.
[0038] Example:
[0039] like Figure 1 As shown, a continuous evaporation-desublimation purification system includes a melting device, a primary sublimator 1, a secondary sublimator 2, a tertiary sublimator 3, a primary desublimator 4, a secondary desublimation unit, and a tertiary desublimator 8. The secondary sublimators 2 and the secondary desublimation units are each provided in two groups, and both groups operate simultaneously. The secondary desublimation unit includes a product desublimator and an exhaust gas desublimator 7. The product desublimator includes a front-end product desublimator 5 and a rear-end product desublimator 6.
[0040] The melting device uses a melting kettle, which is connected to the feed port of the first sublimator 1. The discharge port of the first sublimator 1 is connected to the feed port of the second sublimator 2. The gas outlet of the first sublimator 1 is connected to the gas inlet of the first desublimator 4. The discharge port of the first desublimator 4 is connected to a light component buffer bin 9, which is connected to a light component receiving bin 10. The gas outlet of the first desublimator 4 is connected to a vacuum device 11.
[0041] The outlet of the secondary sublimator 2 is communicated with the inlet of the tertiary sublimator 3, the gas outlet of the secondary sublimator 2 is communicated with the gas inlet of the front product condenser 5, the gas outlet of the front product condenser 5 is communicated with the gas inlet of the rear product condenser 6, and the gas outlet of the rear product condenser 6 is communicated with the gas inlet of the tail gas condenser 7. The outlet of the front product condenser 5 is communicated with the front product buffer bin 13, and the front product buffer bin 13 is communicated with the front product receiving bin 14. The outlet of the rear product condenser 6 is communicated with the rear product buffer bin 15, and the rear product buffer bin 15 is communicated with the rear product receiving bin 16. The outlet of the tail gas condenser 7 is communicated with the tail gas condenser buffer bin 17, the tail gas condenser buffer bin 17 is communicated with the tail gas condenser receiving bin 18, the tail gas condenser receiving bin 18 is communicated with the inlet of the melting device, and the gas outlet of the tail gas condenser 7 is communicated with the vacuum device 11.
[0042] The gas outlet of the tertiary sublimator 3 is communicated with the gas inlet of the tertiary condenser 8, and the gas outlet of the tertiary condenser 8 is also communicated with the vacuum device 11. In this embodiment, the vacuum device 11 is a vacuum pump. The outlet of the tertiary condenser 8 is communicated with the recycled product buffer bin 19, the recycled product buffer bin 19 is communicated with the recycled product receiving bin 20, and the recycled product receiving bin 20 is communicated with the inlet of the melting device. The first condenser 4, the secondary condenser group and the tertiary condenser 8 are all rotary drum condensers.
[0043] The principle of the continuous evaporation and condensation purification system is as follows:
[0044] 1. The ODA dried product and the rear unqualified product are put into the melting kettle, stirred and heated to 190℃, and then continuously fed into the first sublimator 1 for light component removal treatment.
[0045] 2. In the first sublimator 1, the low-boiling-point impurities in the molten ODA are evaporated at 160-200℃ and under the condition of 10-100 Pa absolute pressure, and the evaporated impurity vapor entrains part of the ODA into the first condenser 4, which is cooled to 40-80℃ to crystallize, and the crystals are continuously scraped off at the scraper of the first condenser 4 and then collected into the light component buffer bin 9 and finally collected into the light component receiving bin 10. After a certain amount is collected, the sublimation recovery treatment is carried out.
[0046] 3. The molten ODA, after being de-lightened in the primary sublimator 1, is transferred to the secondary sublimator 2. There, the ODA is heated and evaporated at 190-230°C and an absolute pressure of 10-100 Pa. The evaporated ODA vapor enters the front-end product desublimator 5, where it is cooled to 130-180°C and desublimated and crystallized. The crystals are continuously scraped off by the scraper of the front-end product desublimator 5 and transferred to the front-end product surge bin 13 and the front-end product receiving bin 14 for collection and packaging. The small amount of undesublimated ODA enters the rear-end product desublimator 6 for desublimation and crystallization. The crystals are continuously scraped off by the scraper of the rear-end product desublimator 6 and transferred to the rear-end product surge bin 15 and the rear-end product receiving bin 16 for collection and packaging. The undesublimated ODA and impurities enter the tail gas desublimator 7, where they are cooled and desublimated at 40-50°C. The desublimated product is collected in the tail gas desublimation receiving bin 18 and then returned to the front-end melting kettle for recycling.
[0047] 4. The ODA residual liquid after treatment in the secondary sublimator 2 is transported to the tertiary sublimator 3. In the tertiary sublimator 3, the residual ODA and a small amount of heavy impurities are heated and evaporated at 200-240°C and an absolute pressure of 10-100 Pa. The evaporated ODA and heavy impurity vapors are mixed and enter the tertiary desublimator 8. They are cooled to 40-50°C in the tertiary desublimator 8 for desublimation and crystallization. The crystals are collected in the recovered product receiving bin 20 and then returned to the front-end melting kettle for recycling. The residual liquid is discharged to the waste liquid treatment process.
[0048] The above description is merely an embodiment of the present invention, and the commonly known specific technical solutions and / or features of the solution are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be considered as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection claimed in this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.
Claims
1. A continuous evaporative desublimation purification system, characterized by: The device comprises a melting device, a first sublimator, a second sublimator, a third sublimator, a first condenser, a second condenser and a third condenser, the melting device is communicated with the feeding port of the first sublimator, the discharging port of the first sublimator is communicated with the feeding port of the second sublimator, the gas outlet of the first sublimator is communicated with the gas inlet of the first condenser, the discharging port of the second sublimator is communicated with the feeding port of the third sublimator, the gas outlet of the second sublimator is communicated with the second condenser, and the gas outlet of the third sublimator is communicated with the gas inlet of the third condenser.
2. A continuous evaporative desublimation purification system according to claim 1, wherein: The second condenser comprises a product condenser and a tail gas condenser, and the gas outlet of the product condenser is communicated with the gas inlet of the tail gas condenser.
3. A continuous evaporative desublimation purification system according to claim 2, wherein: The product condenser comprises a front product condenser and a rear product condenser, the gas outlet of the front product condenser is communicated with the gas inlet of the rear product condenser, and the gas outlet of the rear product condenser is communicated with the gas inlet of the tail gas condenser.
4. A continuous evaporative desublimation purification system according to claim 3, wherein: The discharging port of the tail gas condenser and the discharging port of the third condenser are both communicated with the feeding port of the melting device.
5. A continuous evaporative desublimation purification system according to claim 4, wherein: The second sublimator and the second condenser are both provided as two groups and simultaneously operated.
6. A continuous evaporative desublimation purification system according to claim 5, wherein: The discharging port of the first condenser is communicated with a light component buffer bin, the light component buffer bin is communicated with a light component receiving bin, and the gas outlet of the first condenser is communicated with a vacuum device.
7. A continuous evaporative desublimation purification system according to claim 6, wherein: The discharging port of the front product condenser is communicated with a product front buffer bin, the product front buffer bin is communicated with a product front receiving bin, the discharging port of the rear product condenser is communicated with a product rear buffer bin, the product rear buffer bin is communicated with a product rear receiving bin, the discharging port of the tail gas condenser is communicated with a tail gas condensation buffer bin, the tail gas condensation buffer bin is communicated with a tail gas condensation receiving bin, the tail gas condensation receiving bin is communicated with the feeding port of the melting device, and the gas outlet of the tail gas condenser is also communicated with a vacuum device.
8. A continuous evaporative desublimation purification system according to claim 7, wherein: The discharging port of the third condenser is communicated with a recycled product buffer bin, the recycled product buffer bin is communicated with a recycled product receiving bin, the recycled product receiving bin is communicated with the feeding port of the melting device, and the gas outlet of the first condenser is also communicated with a vacuum device.
9. A continuous evaporative desublimation purification system according to claim 8, wherein: The first condenser, the second condenser and the third condenser are all rotary drum condensers.