Device and method for enhancing crystallization, purification and removal of foreign ions under action of electric field

Abstract

The invention provides a device and a method for enhancing crystallization, purification and removal of foreign ions under the action of an electric field, and the device comprises a crystallizer, a first heat exchange medium supply system, a crystallizer cover plate, a crystallization pipe, an anionic membrane, a cationic membrane, an anode plate, a cathode plate, a direct current power supply, a second heat exchange medium supply system and a washing liquid supply system, a heat exchange assembly is arranged outside the crystallizer, the first heat exchange medium supply system can achieve continuous flowing of cooling liquid or heating liquid in the heat exchange assembly, the multiple crystallization pipes are vertically arranged on a crystallizer cover plate, and the crystallizer cover plate is arranged on the upper portion of the crystallizer. A washing liquid inlet is formed between the side wall of the crystallization pipe and the cover plate of the crystallizer, the second heat exchange medium supply system can realize continuous flow of cooling liquid or heating liquid in the crystallization pipe, and the ionic membrane, the cationic membrane, the anode plate and the cathode plate are arranged in the crystallizer. By utilizing the device and the method, the quality of a single crystallization product can be effectively improved.

Description

Technical Field

[0001] The invention relates to the field of crystallization technology, in particular to a device and method for removing impurity ions by strengthening crystallization purification under the action of an electric field. Background Art

[0002] In the process of producing fine chemicals or pharmaceutical products, various impurities will inevitably be produced or mixed in due to factors such as insufficient raw material reaction, long process route, reaction intermediates, catalyst residues and side reactions, which greatly affect the quality of the final product. In order to improve product quality and maximize economic benefits, further refining and purification of the obtained products is an indispensable operation method. There are many methods for refining and purification, and commonly used methods include filtration, extraction, distillation, ion exchange and crystallization.

[0003] Crystallization technology is a method of separating and purifying solutes in a solution through a crystallization process. It uses the different solubility of each component in the mixture in the same solvent or the significant difference in solubility under hot and cold conditions to adjust the operating conditions and crystallize the solute from the solution. As long as crystals are formed, it indicates that the purity of the compound has reached a certain level. Crystallization is one of the important methods for refining solid compounds.

[0004] Compared with other separation operations, crystallization operation is widely used in chemical, food, pharmaceutical, biological, material and other industrial fields due to its advantages of high process selectivity, low energy consumption, low operating temperature, low requirements on equipment materials, and little discharge of "three wastes". However, crystallization separation also has certain limitations, such as low crystallization efficiency, long cycle operation time, low operating flexibility, and low quality of single crystallization products. These characteristics also limit the wide application of crystallization technology to a certain extent. Summary of the invention

[0005] The object of the present invention is to provide a device and method for enhancing crystallization purification and removing impurity ions under the action of an electric field. By using the device and the method, the quality of a single crystal product can be effectively improved.

[0006] The technical solution adopted by the present invention to solve its technical problem is: a device for strengthening crystallization purification and removing impurity ions under the action of an electric field, comprising a crystallizer, a first heat exchange medium supply system, a crystallizer cover plate, a crystallization tube, an anion membrane, a cation membrane, an anode plate, a cathode plate, a DC power supply, a second heat exchange medium supply system, and a washing liquid supply system. A heat exchange component is arranged outside the crystallizer, and the first heat exchange medium supply system can realize the continuous flow of cooling liquid or heating liquid in the heat exchange component. A plurality of the crystallization tubes are vertically arranged on the crystallizer cover plate, and the crystallizer cover plate is arranged on the upper part of the crystallizer and the crystallization tubes are arranged on the upper part of the crystallizer. Located inside the crystallizer, a washing liquid inlet is arranged between the side wall of the crystallizer tube and the crystallizer cover plate, the washing liquid supply system can provide washing liquid to the washing liquid inlet, the second heat exchange medium supply system can realize the continuous flow of cooling liquid or heating liquid in the crystallizer tube, the anion membrane and the cation membrane are arranged in the crystallizer, the anion membrane and the cation membrane separate the inside of the crystallizer into a cathode area, a crystallization area and an anode area, the anode plate is located in the cathode area, the crystallization tube is located in the crystallization area, the cathode plate is located in the anode area, and the DC power supply is electrically connected to the anode plate and the cathode plate.

[0007] Preferably, the crystallization tube is provided with an opening at the upper portion and a closed lower portion, a baffle is provided inside the crystallization tube, the baffle separates the inner upper side of the crystallization tube into a liquid inlet area and a liquid outlet area, and a through opening is provided below the baffle for achieving communication between the lower portion of the liquid inlet area and the lower portion of the liquid outlet area.

[0008] Furthermore, the crystal tube is cylindrical or strip-shaped.

[0009] Furthermore, the washing liquid inlet includes a lower embracing port and an upper liquid inlet, the lower embracing port is arranged at the lower part of the crystallizer cover plate and surrounds the outer side of the corresponding crystallization tube, and several upper liquid inlets are arranged on the outer side of the circumference of the corresponding crystallization tube and the upper liquid inlets are small at the top and large at the bottom, the upper part of the upper liquid inlet is connected to the outside, and the lower part of the upper liquid inlet is connected to the lower embracing port.

[0010] Furthermore, a guide slope is provided on the inner and outer side walls of the upper liquid inlet, and the upper end of the guide slope is distributed in an outwardly inclined state relative to the corresponding crystal tube side wall.

[0011] Furthermore, an enclosure is arranged on the upper periphery of the crystallizer cover plate, and a plurality of partitions are arranged inside the enclosure to divide it into a plurality of pouring areas, and the upper opening of the crystallizer is located in the corresponding pouring area.

[0012] Furthermore, the heat exchange component is a hollow interlayer cavity arranged outside the side wall of the crystallizer, a first liquid inlet pipe is arranged at the left bottom of the hollow interlayer cavity, and a first liquid outlet pipe is arranged at the right upper part of the hollow interlayer cavity.

[0013] Furthermore, the second heat exchange medium supply system includes a plurality of branch pipe groups, each of which includes a liquid inlet branch main pipe and a liquid outlet branch main pipe, and each of which is distributed on the upper part of a corresponding horizontal row of crystal tubes. A plurality of second liquid inlet pipes are arranged on the liquid inlet branch main pipe, and the second liquid inlet pipes are connected to the upper part of the liquid inlet area. A plurality of second liquid outlet pipes are arranged on the liquid outlet branch main pipe, and the second liquid outlet pipes are connected to the upper part of the liquid outlet area.

[0014] Furthermore, a first drain pipe, a second drain pipe, and a third drain pipe are arranged at the bottom of the crystallizer, and the first drain pipe, the second drain pipe, and the third drain pipe are respectively connected with the cathode area, the crystallization area, and the anode area, and a switch valve is arranged at the lower part of the first drain pipe, the second drain pipe, and the third drain pipe.

[0015] A method for removing impurity ions by strengthening crystallization purification under the action of an electric field, comprising the above-mentioned device for removing impurity ions by strengthening crystallization purification under the action of an electric field, and further comprising the following steps:

[0016] S1. Add an appropriate amount of mother solution to be crystallized into the cathode area, crystallization area and anode area in the crystallizer, and ensure that the switch valve is in a closed state before adding the crystallization mother solution;

[0017] S2, starting the first heat exchange medium supply system so that the cooling liquid is continuously introduced into the hollow interlayer cavity, and starting the second heat exchange medium supply system so that the cooling liquid is continuously introduced into each crystallization tube; the temperature of the cooling liquid supplied by the second heat exchange medium supply system is 10-30° C. lower than the initial crystallization temperature of the mother liquid to be crystallized;

[0018] S3. While the cooling liquid is continuously introduced into the crystallization tube, the changing state of the periphery of the crystallization tube is constantly observed. When a layer of crystals appears on the side wall of the crystallization tube, the second heat exchange medium supply system is turned off.

[0019] S4, after the second heat exchange medium supply system is turned off, the first heat exchange medium supply system is controlled so that the mother liquid to be crystallized in the crystallizer is cooled down at a certain cooling rate, and the crystallization mother liquid is continuously crystallized during the continuous cooling process; at the same time, after the second heat exchange medium supply system is turned off, the DC power supply is powered on the anode plate and the cathode plate;

[0020] S5, after the crystallization process continues for a certain period of time, the first heat exchange medium supply system is turned off, and at the same time, the power supply to the cathode plate and the anode plate is turned off;

[0021] S6, all the switch valves are opened to discharge the remaining crystallization mother liquor from the crystallizer. After the crystallization mother liquor is discharged, the washing liquid supply system is started to simultaneously fill the washing liquid into the plurality of filling areas. The washing liquid flows into the crystals on the side wall of the crystallization tube through the washing liquid inlet. After the crystals on the crystallization tube are continuously washed with the washing liquid for a certain period of time, the washing operation of the crystals is stopped. During the continuous introduction of the washing liquid into the filling area, the washing liquid in the filling area is allowed to completely submerge the washing liquid inlet in the area and continue for a certain period of time.

[0022] S7, after the crystal washing operation is completed, the middle switch valve is closed, and then the second heat exchange medium supply system is started, so that the heating liquid is continuously introduced into the crystallization tube, and the temperature of the heating liquid is 3-10°C higher than the melting point of the crystal; after the heating liquid is introduced for a certain period of time, the crystals on the crystallization tube fall off from the crystallization tube and fall into the bottom of the crystallizer;

[0023] S8. After all the crystals fall off the crystallization tube, the second heat exchange medium supply system is turned off, and then the first heat exchange medium supply system is started, so that the first heat exchange medium supply system continuously passes heating liquid into the hollow interlayer cavity, and the temperature of the heating liquid is 10-30°C higher than the melting point of the crystal; after the crystal is completely melted, the operation of the second heat exchange medium supply system is stopped, and then the middle switch valve is opened to collect the melted crystallization liquid, thereby completing the crystallization purification.

[0024] The beneficial effects of the present invention are:

[0025] 1. By using the energized anode and cathode plates, a stable electric field is formed in the crystallization mother liquor. The charged impurity ions in the crystallization mother liquor can move under the action of the electric field and be enriched and isolated in the corresponding area through the anion and cation membranes, thereby realizing the removal of charged impurity ions in the crystallization area. The charged impurity ions in the crystallization area are effectively removed, and the single crystallization impurity removal efficiency can be improved during the crystallization process of the crystallization mother liquor, and the quality of the crystallized product can be improved. After experimental comparison, the impurity ion removal rate is increased by 50-90%, and the particle size of the product is large and regular.

[0026] 2. The washing liquid inlets distributed around the crystallization tube can be used to wash the crystals on the crystallization tube, thereby facilitating the crystal washing operation; the upper liquid inlet is small at the top and large at the bottom, the guide slope is designed, and the lower embracing port embraces the side wall of the crystallization tube, so that the washing liquid can flow downward along the entire side wall of the crystallization tube, thereby facilitating the washing of the entire outer side of the crystal; at the same time, the function of the enclosure and the partition can make it easier for the washing liquid to flood the upper liquid inlet, thereby ensuring the washing liquid flow rate of the upper liquid inlet, and then facilitating the improvement of the washing effect.

[0027] 3. By utilizing the principle of gravity, the steps of crystal washing, crystallization and collection can be realized without adding any auxiliary equipment, making the crystallization operation simple and easy. At the same time, multiple crystallization tubes can be used to generate crystals synchronously, thereby improving the efficiency of crystallization operation and the production efficiency of crystal products.

[0028] 4. The first and third liquid discharge pipes can be used to discharge the crystallization mother liquor containing a large number of charged impurity ions, thereby facilitating the crystallizer to repeat the crystallization operation.

[0029] 5. The bottom of the liquid inlet area and the liquid outlet area in the crystallization tube are connected by a through hole, so that during the crystallization operation, the cooling liquid or the heating liquid can flow in a U-shaped line in the crystallization tube. The U-shaped flow of the heating liquid or the cooling liquid can improve the full diffusion of the heating liquid or the cooling liquid in the crystallization tube, thereby improving the heat exchange between the heating liquid or the cooling liquid and the crystal or the crystallization mother liquor, thereby ensuring the decrystallization effect or the quality of the formation of the initial crystal thin layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is an internal schematic diagram of the present invention;

[0032] Figure 2 A top view of a first embodiment of the present invention;

[0033] Figure 3 A top view of a second embodiment of the present invention;

[0034] Figure 4 It is a schematic diagram of the combination of the crystallizer cover plate and the crystallizer tube;

[0035] Figure 5It is a schematic diagram of the structure of the washing liquid inlet;

[0036] Figure 6 It is a longitudinal partial cross-sectional view of the junction between the crystallization tube and the crystallizer cover plate;

[0037] Figure 7 for Figure 1 Enlarged view of point A in the middle;

[0038] Figure 8 for Figure 1 Enlarged view of point B in the middle;

[0039] Fig. 9 for Figure 2 Enlarged view of point C in the middle;

[0040] Fig.10 for Figure 3 Enlarged view of point D in the middle;

[0041] Fig.11 for Figure 4 Enlarged view of point E in the middle;

[0042] In the figure: 1 crystallizer, 11 hollow interlayer cavity, 111 first liquid inlet pipe, 112 first liquid outlet pipe, 12 first liquid drain pipe, 13 second liquid drain pipe, 14 third liquid drain pipe, 15 switch valve, 2 crystallizer cover plate, 21 washing liquid inlet, 211 lower surrounding port, 212 upper liquid inlet, 213 guide slope, 22 enclosure, 23 partition, 24 perfusion area, 3 crystallization tube, 31 baffle, 32 liquid inlet area, 33 liquid outlet area, 34 through port, 4 anion membrane, 5 cationic membrane, 6 anode plate, 7 cathode plate, 101 cathode area, 102 crystallization area, 103 anode area, 104 crystallization mother liquor, 105 liquid inlet branch main pipe, 106 second liquid inlet pipe, 107 liquid outlet branch main pipe, 108 second liquid outlet pipe. DETAILED DESCRIPTION

[0043] The following will be combined with specific embodiments and attached Figure 1-11 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the preferred embodiments of the present invention, rather than all the embodiments. Those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0044] The present invention provides a device for strengthening crystallization purification and removing impurity ions under the action of an electric field (such as Figure 1As shown in the figure, it includes a crystallizer 1 and a first heat exchange medium supply system. The crystallizer 1 is a mature and known technical product on the existing market. It is mainly used to hold the crystallization mother liquid 104 and provide a low-temperature environment for cooling and crystallizing the crystallization mother liquid 104. A heat exchange component is arranged outside the crystallizer 1. In practical applications, the heat exchange component is mainly used to achieve heating or cooling of the crystallization mother liquid 4 inside the crystallizer 1. Its structure can be a spiral sleeve directly sleeved on the outside of the crystallizer 1, or it can be a hollow interlayer cavity 11 arranged on the outside of the side wall of the crystallizer 1, and a heat exchange medium supply system is arranged at the bottom of the left side of the hollow interlayer cavity 11. A first liquid inlet pipe 111 is provided at the upper right side of the hollow interlayer cavity 11, and a first liquid outlet pipe 112 is provided. The cooling or heating of the crystallization mother liquid 4 inside the crystallizer 1 is realized by the flow of the cooling liquid or the heating liquid in the spiral sleeve or the hollow interlayer cavity 11. The first heat exchange medium supply system can realize the continuous flow of the cooling liquid or the heating liquid in the heat exchange component. The first heat exchange medium supply system is essentially a circulation supply system of a cold source and a heat source. For the cold source, the existing cooling device (such as an industrial refrigerator) is used to realize the continuous supply of the cooling liquid, and for the heat source, the existing The heating device (such as a heating wire heating device, a high-temperature steam heating device) realizes the continuous supply of the heating liquid, and the flow of the cooling liquid or the heating liquid can be directly realized by a delivery pump. Furthermore, the existing automatic control technology can be used to realize the uniform cooling control of the crystallization mother liquor 4 in the crystallizer 1, such as using a temperature sensor to realize the real-time collection of the temperature of the crystallization mother liquor 4, and the collected temperature signal is transmitted to the controller in real time. The controller controls the temperature and delivery flow of the heat source or cold source output by the heating device or the cooling device according to the set cooling speed requirement and the collected real-time temperature value, thereby realizing the crystallization. The temperature rise or drop rate in the heat exchanger 1 is controlled. In this specific embodiment, the heat exchange component uses a hollow interlayer cavity 11. The first liquid inlet pipe 111 is connected in parallel with the heating pipe and the cooling pipe in the first heat exchange medium supply system by a pipeline. The heating pipe and the cooling pipe are provided with a switch valve to realize the separate supply of heating liquid or cooling liquid to the first liquid inlet pipe 111. The first liquid outlet pipe 112 is connected in parallel with the heat source return pipe and the cooling source return pipe in the first heat exchange medium supply system through a pipeline, and a switch valve is provided on the heat source return pipe and the cooling source return pipe to realize the effective reflux of the heating liquid or cooling liquid.The device for removing impurity ions also includes a crystallizer cover plate 2, a crystallization tube 3, an anion membrane 4, a cation membrane 5, an anode plate 6, a cathode plate 7, a DC power supply, a second heat exchange medium supply system, and a washing liquid supply system. The anion membrane 4, the cation membrane 5, the anode plate 6, and the cathode plate 7 are all known mature technology products in the prior art, so the detailed structure of the anion membrane 4, the cation membrane 5, the anode plate 6, and the cathode plate 7 will not be described in detail. The anion membrane 4 mainly realizes the circulation filtration of charged anions, the cation membrane 5 mainly realizes the circulation filtration of charged cations, and the anode plate 6 and the cathode plate 7 are mainly used to realize the charged anions and cations in the crystallization mother liquor 4. In order to achieve directional enrichment, a plurality of the crystallization tubes 3 are vertically arranged on the crystallizer cover plate 2. In practical applications, the number and spacing of the crystallization tubes 3 can be specifically set according to the size of the crystallizer cover plate 2 and the crystallization requirements. The crystallization tubes 3 are mainly used as crystallization carriers so that the crystallization mother liquor 4 can achieve effective crystallization. The crystallization tubes 3 are distributed throughout the entire depth range of the crystallization mother liquor and the number of the crystallization tubes 3 is large. In the process of continuous cooling of the crystallization mother liquor 4, the crystallization efficiency can be improved. The crystallizer cover plate 2 is arranged on the upper part of the crystallizer 1 and the crystallization tubes 3 are located inside the crystallizer 1. A washing liquid inlet 2 is arranged between the side wall of the crystallization tube 3 and the crystallizer cover plate 2. 1, the washing liquid supply system can provide washing liquid to the washing liquid inlet 21. The washing liquid supply system is actually a washing liquid delivery system, which can be composed of a delivery pump, a delivery pipeline and a container for storing washing liquid. The delivery function of the delivery pump can continuously deliver the washing liquid in the container to the corresponding washing liquid inlet 21 through the delivery pipeline. In order to facilitate the control of the delivery of the washing liquid, a relevant control valve can be set on the delivery pipeline to achieve flow control of the washing liquid. At the same time, a variable pump can also be used to achieve flow control of the washing liquid. The washing liquid flowing out of the washing liquid inlet 21 can be used to control the surface of the crystal hung on the crystal tube 3. Washing is performed, thereby improving the quality of the crystal product; the second heat exchange medium supply system can realize the continuous flow of cooling liquid or heating liquid in the crystallization tube 3. The supply principle of the second heat exchange medium supply system is the same as that of the heating liquid and cooling liquid of the first heat exchange medium supply system, so it will not be described in detail here. In this specific embodiment, by continuously introducing a cooling liquid of a certain temperature into the crystallization tube 3, the formation of crystal seeds is realized, thereby facilitating the subsequent improvement of crystal quality. By continuously introducing a heating liquid of a certain temperature into the crystallization tube 3, it is convenient to melt and fall off the crystals on the outer wall of the crystallization tube 3, thereby facilitating the subsequent collection of crystals;The anion membrane 4 and the cation membrane 5 are arranged in the crystallizer 1, and the anion membrane 4 and the cation membrane 5 divide the interior of the crystallizer 1 into a cathode area, a crystallization area and an anode area. The isolation effect of the anion membrane 4 and the cation membrane 5 is utilized so that the crystallization mother liquor 4 in the cathode area, the crystallization area and the anode area will not flow and mix with each other, the anion membrane 4 can only allow charged anions to pass through, and the cation membrane 5 can only allow charged cations to pass through. The anode plate 6 is located in the cathode area, the crystallization tube 3 is located in the crystallization area, the cathode plate 7 is located in the anode area, and the DC power supply is electrically connected to the anode plate 6 and the cathode plate 7. In practical applications, after a certain amount of crystallization mother solution 4 is poured into the cathode area, crystallization area and anode area, and a DC power supply is connected to the anode plate 6 and the cathode plate 7, an electric field is formed between the anode plate 6, the crystallization mother solution 4 and the cathode plate 7. Under the action of electric field enhancement, the anions and cations in the crystallizer 1 move in a directional manner in the solution to be crystallized 4. The cations move toward the cathode plate 7 and reach the surface of the cation membrane 5. The cation membrane 5 has the characteristics of selective permeability: only cations are allowed to pass through, and anions are blocked on the surface of the cation membrane 5; similarly, anions move toward the anode plate 6 and reach the surface of the anion membrane 4, pass through the anion membrane, and cations are blocked on the surface of the anion membrane 4. As time goes on, the anion and cation content in the middle crystallization area of ​​the crystallizer 1 gradually decreases. The anions and cations enriched in the cathode area and the anode area will not diffuse into the crystallization area again under the adsorption of the corresponding anode plate 6 and the cathode plate 7, thereby ensuring the removal effect of anions and cations in the crystallization area, and then greatly improving the quality of the product obtained in the crystallization area. The directional electric field only acts on the anions and cations that are ionized by hydrolysis: under the action of the DC directional electric field, the anions and cations are enriched in the anode and cathode regions respectively. Due to their characteristics, organic compounds that cannot be ionized are not affected by the electric field and still crystallize in the initial manner. By using this method for crystallization purification, a product with the same crystal structure and properties as the previous crystal can be obtained. ;

[0045] In practical applications, in order to facilitate the cooling liquid or the heating liquid to flow in the entire area inside the crystallization tube 3, so as to improve the heat exchange effect between the cooling liquid or the heating liquid in the crystallization tube 3 and the crystallization mother liquid 4 outside the crystallization tube 3, an opening is provided at the upper part of the crystallization tube 3 and the lower part is closed, and a baffle 31 is provided inside the crystallization tube 3. The baffle 31 divides the upper side of the interior of the crystallization tube 3 into a liquid inlet area 32 and a liquid outlet area 33. The baffle 31 realizes the sealing and isolation of the corresponding areas of the liquid inlet area 32 and the liquid outlet area 33. A through hole 34 is provided below the baffle 31 for connecting the lower part of the liquid inlet area 32 with the lower part of the liquid outlet area 33. The heating liquid or cooling liquid flowing in from the upper part of the liquid inlet area 32 continuously flows downward and enters the bottom of the liquid outlet area 33 through the through hole 34, and finally flows out of the crystallization tube 3 from the upper part of the liquid outlet area 33. The heating liquid or cooling liquid flows in the crystallization tube 3 in a U-shaped line, which is beneficial to sufficient heat exchange between the heating liquid or cooling liquid and the crystallization mother liquor 4, thereby improving the cooling or heating effect. In practical applications, the number of crystal tubes 3 is generally large. In order to facilitate the synchronous inflow of heating liquid or cooling liquid into all crystal tubes 3 as much as possible, the second heat exchange medium supply system includes several groups of branch pipe groups. In practical applications, the number of branch pipe groups corresponds to the number of rows of crystal tubes 3. If there are several rows of crystal tubes 3, several groups of branch pipe groups are set. Each group of branch pipe groups includes a liquid inlet branch main pipe 105 and a liquid outlet branch main pipe 107. One end of the liquid inlet branch main pipe is closed, and the other end is connected in parallel with the heating main pipe and the cooling main pipe of the second heat exchange medium supply system. At the same time, switch valves are provided on the heating main pipe and the cooling main pipe. The switch valves are used to realize the supply of heating liquid or cooling liquid to the liquid inlet branch main pipe 105, and the liquid outlet branch main pipe 107 is connected to the second heat exchange medium supply system. The heat source return pipe and the cold source return pipe are connected in parallel, and switch valves are arranged on the heat source return pipe and the cold source return pipe, and the smooth reflux of the heating liquid or the cooling liquid is realized by controlling the switch valve; each group of the branch pipe groups is distributed on the upper part of a corresponding horizontal row of crystallization tubes, and a plurality of second liquid inlet pipes 106 are arranged on the liquid inlet branch main pipe 105, and the second liquid inlet pipes 106 are connected to the upper part of the liquid inlet area 32; a plurality of second liquid outlet pipes 108 are arranged on the liquid outlet branch main pipe 107, and the second liquid outlet pipes 108 are connected to the upper part of the liquid outlet area 33; each crystallization tube in a row corresponds to a second liquid inlet pipe 106, so as to ensure that the heating liquid or the cooling liquid is synchronously introduced into all the crystallization tubes 3 in the row, and then the synchronous heat exchange of all the crystallization tubes 3 can be effectively ensured.

[0046] In practical applications, the crystal tube 3 can be cylindrical or strip-shaped. When the crystal tube 3 is cylindrical, its appearance is a long test tube (such as Figure 1 ,like Figure 4 As shown), when the crystal tube 3 is in the shape of a long strip, its top view is as follows Figure 3To ensure that the long strip crystal tube 3 does not block the movement of ions too much, the length direction of the long strip crystal tube 3 is distributed along the normal direction of the anion membrane.

[0047] On the basis of the above embodiment, the specific implementation of the washing liquid inlet 21 is as follows: the washing liquid inlet 21 includes a lower embracing port 211 and an upper liquid inlet 212, wherein the lower embracing port 211 is arranged at the lower part of the crystallizer cover plate 2 and surrounds the outer side of the corresponding crystallization tube 3. The lower embracing port 211 surrounds the outer side of the crystallization tube 3, which makes it convenient for the washing liquid to surround the entire outer side of the crystallization tube 3, thereby making it convenient for the washing liquid to achieve all-round washing of the crystals on the crystallization tube 3; a plurality of the upper liquid inlets 212 are arranged on the outer side of the circumference of the corresponding crystallization tube 3 and the upper liquid inlets 212 are small at the top and large at the bottom, and the upper liquid inlets 212 are small at the top and large at the bottom. The upper part of the upper liquid inlet 212 is connected to the outside, and the lower part of the upper liquid inlet 212 is connected to the lower surrounding opening 211. The upper liquid inlet 212 is small at the top and large at the bottom, which is convenient for the lower surrounding opening 211 to be filled with washing liquid, thereby improving the washing effect of the crystal. In order to enable the washing liquid to effectively flow to the side wall of the crystallization tube 3, a guide slope 213 is provided on the inner and outer side walls of the upper liquid inlet 212. The upper end of the guide slope 213 is distributed in an outwardly inclined state relative to the corresponding side wall of the crystallization tube 3. The guiding effect of the guide slope 213 is utilized to make the flowing washing liquid continuously flow toward the side wall of the crystallization tube 3. Furthermore, when washing the crystals on the side wall of the crystallization tube 3 with washing liquid, in order to ensure that a certain amount of washing liquid flows into each washing liquid inlet 21, an enclosure 22 is arranged on the upper periphery of the crystallizer cover plate 2, and a plurality of partitions 23 are arranged in the enclosure 22 to divide it into a plurality of perfusion areas 24. The upper opening of the crystallizer 3 is located in the corresponding perfusion area 24. In actual application, the perfusion area 24 can effectively prevent the washing liquid therein from further diffusing and flowing by utilizing the sealing effect of the enclosure 22 and the partition 23. When the washing liquid is continuously introduced into the perfusion area 24 and the washing liquid is always kept to submerge all the washing liquid inlets 21, it can be smoothly ensured that all crystal products below the perfusion area 24 are effectively washed by the washing liquid.

[0048] In practical applications, after one crystallization is completed, in order to discharge the remaining crystallization mother liquor 4 so as to repeat the subsequent crystallization operation, a first drain pipe 12, a second drain pipe 13, and a third drain pipe 14 are arranged at the bottom of the crystallizer 3. The first drain pipe 12, the second drain pipe 13, and the third drain pipe 14 are respectively connected to the cathode area, the crystallization area, and the anode area, and a switch valve 15 is arranged at the lower part of the first drain pipe 12, the second drain pipe 13, and the third drain pipe 14.

[0049] The present invention also provides a method for removing impurity ions by strengthening crystallization purification under the action of an electric field, comprising the above-mentioned device for removing impurity ions by strengthening crystallization purification under the action of an electric field, and the method further comprises the following steps:

[0050] S1. Add an appropriate amount of the mother solution 4 to be crystallized into the cathode region, the crystallization region and the anode region in the crystallizer 1. Ensure that the switch valve 15 is in a closed state before adding the crystallization mother solution 4. To ensure a better impurity ion removal effect, when injecting the crystallization mother solution 4, try to keep the liquid levels of the crystallization mother solution 4 in the cathode region, the crystallization region and the anode region level;

[0051] S2, start the first heat exchange medium supply system, so that the cooling liquid is continuously introduced into the hollow interlayer cavity 11, and the cooling liquid introduced into the hollow interlayer cavity 11 realizes the cooling of the crystallization mother liquor 4 in the entire range of the crystallizer 1, and provides conditions for subsequent crystallization precipitation. The temperature of the cooling liquid supplied by the first heat exchange medium supply system is specifically set according to the characteristics of the crystallization mother liquor 4 and the crystallization requirements, and the second heat exchange medium supply system is started, so that the cooling liquid is continuously introduced into each crystallization tube; the temperature of the cooling liquid supplied by the second heat exchange medium supply system is 10-30°C lower than the initial crystallization temperature of the mother liquor to be crystallized; the cooling liquid is supplied by the second heat exchange medium supply system, and a seed crystal can be formed on the side wall of the crystallization tube 3, so as to smoothly realize the subsequent crystal formation;

[0052] S3, while the cooling liquid is continuously introduced into the crystallization tube 3, the changing state of the periphery of the crystallization tube 3 is constantly observed. When a layer of crystals appears on the side wall of the crystallization tube 3, the second heat exchange medium supply system is turned off. At this time, the seed crystal is formed;

[0053] S4, after the second heat exchange medium supply system is turned off, the first heat exchange medium supply system is controlled to keep the mother liquid 4 to be crystallized in the crystallizer 3 at a certain cooling rate for continuous cooling. The specific cooling rate is determined according to the characteristics of the crystallization mother liquid 4 and the crystallization requirements. During the continuous cooling process, the crystallization mother liquid 4 is continuously crystallized. Different from the common practice of directly adding crystal seeds to the solution, the crystals grow slowly with the crystal seeds on the side wall of the crystallization tube 3 as the center. Crystallization in this way can obtain crystals with perfect crystal form and excellent quality. At the same time, after the second heat exchange medium supply system is turned off, the DC power supply is energized for the anode plate 6 and the cathode plate 7. After the anode plate 6 and the cathode plate 7 are energized, an electric field is formed in the crystallization mother liquid 4, so that during the crystallization process, the charged ions in the crystallization zone are continuously removed, which is convenient for improving the quality of the crystallized product in the crystallization zone.

[0054] S5, after the crystallization process continues for a certain period of time, the first heat exchange medium supply system is turned off, and at the same time, the power supply of the cathode plate 7 and the anode plate 6 is turned off; this step completes the crystal production process. During the crystal production process, the thickness of the crystals on the crystallization tube 3 should be observed at all times to prevent the crystals on two adjacent crystallization tubes 3 from contacting each other, which is not conducive to the subsequent crystal washing;

[0055] S6, all the switch valves 15 are opened to discharge the remaining crystallization mother liquor 4 from the crystallizer 3. After the crystallization mother liquor 4 is discharged, the washing liquid supply system is started to simultaneously fill the washing liquid into the plurality of filling areas 24. The washing liquid flows into the crystals on the side wall of the crystallization tube 3 through the washing liquid inlet 21. After the crystals on the crystallization tube 3 are continuously washed with the washing liquid for a certain period of time, the washing operation of the crystals is stopped. The washing time is determined according to actual needs. During the continuous introduction of the washing liquid into the filling area 24, the washing liquid in the filling area 24 can completely submerge the washing liquid inlet 21 in the area and continue for a certain period of time. In this way, the washing effect of the crystals on the side wall of the crystallization tube 3 can be improved, thereby ensuring the quality of the final crystal product.

[0056] S7, after the crystal washing operation is completed, the middle switch valve 15 is closed, and then the second heat exchange medium supply system is started, so that the heating liquid is continuously introduced into the crystallization tube 3, and the temperature of the heating liquid is 3-10°C higher than the melting point of the crystal; after the heating liquid is introduced for a certain period of time, the crystals on the crystallization tube 3 fall off from the crystallization tube 3 under the action of gravity and fall into the bottom of the crystallizer 1; at this time, the crystallization step is completed, and at the same time, this crystallization method is convenient and fast, which is conducive to improving the efficiency of the crystallization operation;

[0057] S8. After all the crystals fall off the crystallization tube 3, the second heat exchange medium supply system is turned off, and then the first heat exchange medium supply system is started, so that the first heat exchange medium supply system continuously passes heating liquid into the hollow interlayer cavity 11, and the temperature of the heating liquid is 10-30°C higher than the melting point of the crystal; after the crystal is completely melted, the operation of the second heat exchange medium supply system is stopped, and then the middle switch valve 15 is opened to collect the melted crystallization liquid, thereby completing the crystallization purification.

[0058] The present invention also provides comparative examples 1-4 of experiments using the above-mentioned device and method for removing impurity ions.

[0059] Comparative Example 1

[0060] The crystallizer 1 used in this embodiment is as follows Figure 1As shown, direct current is not passed through the anode plate 6 and the cathode plate 7, and no electric field is applied. The phosphoric acid solution to be crystallized is added to the crystallizer 1 (using a test tube-shaped crystallization tube 3), and -10°C condensate is passed through the liquid inlet area of ​​the crystallization tube 3. After about 5 minutes, a layer of crystals appears on the surface of the crystallization tube 3, and the passage of condensate is stopped. The temperature cooling rate in the crystallizer 1 is controlled at 0.2°C / h, and the crystallization mother liquor is discharged after 20 hours of crystallization. Under the action of gravity, the washing liquid is passed into the perfusion area in the crystallizer cover plate 2, flows through the crystal layer through the washing liquid inlet 21, and the crystal washing is completed. A 40°C liquid is passed into the liquid inlet area of ​​the crystallization tube 3 for about 3 minutes, and the crystals gradually fall off from the crystallization tube 3 to obtain the crystallization product of this time.

[0061] Comparative Example 2

[0062] This embodiment uses the same crystallizer 1 as in Comparative Example 1, and connects direct current (voltage 12V) to the anode plate 6 and the cathode plate 7 to form a stable electric field between the two. Other operating conditions are exactly the same as in Comparative Example 1. The crystals of Comparative Examples 1 and 2 were analyzed and detected, and the cation and anion detection was performed using an ICS-2100 ion chromatograph, and the iron ion concentration was determined using the method specified in the national standard GB / T22596-2008. The results are shown in Table 1 below:

[0063] Table 1

[0064] sample <![CDATA[Fe 2+ / 3+ / ppm]]> <![CDATA[Cu 2+ / ppm]]> <![CDATA[Na + / ppm]]> <![CDATA[K + / ppm]]> <![CDATA[F - / ppm]]> <![CDATA[Cl - / ppm]]> Comparative Example 1 20.2 15.0 22.3 13.5 9.8 12.7 Comparative Example 2 11.5 8.1 6.1 5.6 3.2 6.4

[0065] It can be seen from Table 1 that the anion and cation removal rate of Comparative Example 2 is 46-67% higher than that of Comparative Example 1, indicating that the crystallization purification under electric field enhancement has a better effect in removing impurity ions.

[0066] Comparative Example 3

[0067] The crystallizer 1 used in this embodiment is as follows Figure 1 As shown, direct current is not passed through the anode plate 6 and the cathode plate 7, and no electric field is applied. The imidazole solution to be crystallized is added to the crystallizer 1 (using a test tube-shaped crystallization tube 3), and a 25°C condensate is passed through the liquid inlet area of ​​the crystallization tube 3. After about 7 minutes, a layer of crystals appears on the surface of the crystallization tube 3, and the condensate is stopped. The temperature cooling rate in the crystallizer 1 is controlled at 0.25°C / h, and the crystallization mother liquor is discharged after 18 hours of crystallization. Under the action of gravity, the washing liquid is passed into the perfusion area in the crystallizer cover plate 2, flows through the crystal layer through the washing liquid inlet 21, and the crystal washing is completed. A 65°C liquid is passed into one side of the crystallization tube 3 for about 3 minutes, and the crystals gradually fall off from the crystallization tube 3 to obtain the crystallization product of this time.

[0068] Example 4

[0069] This embodiment uses the same crystallizer as in Example 1, and connects direct current (voltage 15V) to the anode plate 6 and the cathode plate 7 to form a stable electric field between the two. Other operating conditions are exactly the same as those in Comparative Example 3. The crystals of Comparative Examples 3 and 4 were analyzed and detected, and the cation and anion detection was performed using an ICS-2100 ion chromatograph, and the iron ion concentration was determined using the method specified in the national standard GB / T22596-2008. The results are shown in Table 2 below:

[0070] Table 2

[0071]

[0072]

[0073] As can be seen from Table 2, the removal rate of anions and cations in Comparative Example 4 is 51-83% higher than that in Comparative Example 3, indicating that the crystallization purification under electric field enhancement has a better effect in removing impurity ions. Compared with Comparative Examples 1 and 2, the removal rate of Comparative Example 4 is higher than that of Example 3, indicating that this method is more effective in the crystallization process of organic compounds.

[0074] In the present invention, "up", "down", "front", "back", "left" and "right" are relative positions used to conveniently describe positional relationships, and therefore cannot be understood as absolute positions to limit the scope of protection.

[0075] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

[0076] The above description in combination with the accompanying drawings has detailed the preferred implementation modes and embodiments of the present invention, but the present invention is not limited to the above implementation modes and embodiments. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the concept of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for removing impurity ions by enhanced crystallization purification under the action of an electric field, comprising a crystallizer and a first heat exchange medium supply system, wherein a heat exchange component is arranged outside the crystallizer, and the first heat exchange medium supply system can realize continuous flow of cooling liquid or heating liquid in the heat exchange component, wherein: The device for removing impurity ions also includes a crystallizer cover plate, a crystallizer tube, an anion membrane, a cation membrane, an anode plate, a cathode plate, a direct current power supply, a second heat exchange medium supply system, and a washing liquid supply system. Several of the crystallizer tubes are vertically arranged on the crystallizer cover plate, the crystallizer cover plate is arranged on the upper part of the crystallizer and the crystallizer tubes are located inside the crystallizer, a washing liquid inlet is arranged between the side wall of the crystallizer tube and the crystallizer cover plate, the washing liquid supply system can provide washing liquid to the washing liquid inlet, the second heat exchange medium supply system can realize continuous flow of cooling liquid or heating liquid in the crystallizer tube, the anion membrane and the cation membrane are arranged in the crystallizer, the anion membrane and the cation membrane divide the interior of the crystallizer into a cathode area, a crystallization area and an anode area, the anode plate is located in the cathode area, the crystallization tube is located in the crystallization area, the cathode plate is located in the anode area, and the direct current power supply is electrically connected to the anode plate and the cathode plate.

2. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 1, characterized in that: The crystallization tube is provided with an opening at the top and a closed bottom. A baffle is provided inside the crystallization tube. The baffle divides the upper inner side of the crystallization tube into a liquid inlet area and a liquid outlet area. A through opening is provided below the baffle to realize the connection between the lower part of the liquid inlet area and the lower part of the liquid outlet area.

3. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 2, characterized in that: The crystal tube is cylindrical or strip-shaped.

4. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 2, characterized in that: The washing liquid inlet includes a lower embracing port and an upper liquid inlet. The lower embracing port is arranged at the lower part of the crystallizer cover plate and surrounds the outer side of the corresponding crystallization tube. Several upper liquid inlets are arranged on the outer side of the circumference of the corresponding crystallization tube and the upper liquid inlets are small at the top and large at the bottom. The upper part of the upper liquid inlet is connected to the outside world, and the lower part of the upper liquid inlet is connected to the lower embracing port.

5. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 4, characterized in that: A flow guiding slope is arranged on the inner and outer side walls of the upper liquid inlet, and the upper end of the flow guiding slope is distributed in an outwardly inclined state relative to the corresponding side wall of the crystal tube.

6. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 4, characterized in that An enclosure is arranged on the periphery of the upper part of the crystallizer cover plate, and a plurality of partitions are arranged inside the enclosure to divide the crystallizer into a plurality of pouring areas. The upper opening of the crystallizer is located in the corresponding pouring area.

7. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 6, characterized in that: The heat exchange component is a hollow interlayer cavity arranged outside the side wall of the crystallizer, a first liquid inlet pipe is arranged at the left bottom of the hollow interlayer cavity, and a first liquid outlet pipe is arranged at the right upper part of the hollow interlayer cavity.

8. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 7, characterized in that: The second heat exchange medium supply system includes a plurality of branch pipe groups, each of which includes a liquid inlet branch main pipe and a liquid outlet branch main pipe, and each of which is distributed on the upper part of a corresponding horizontal row of crystal tubes. A plurality of second liquid inlet pipes are arranged on the liquid inlet branch main pipe, and the second liquid inlet pipes are connected to the upper part of the liquid inlet area. A plurality of second liquid outlet pipes are arranged on the liquid outlet branch main pipe, and the second liquid outlet pipes are connected to the upper part of the liquid outlet area.

9. The device for removing impurity ions by enhanced crystallization purification under electric field according to claim 8, characterized in that The bottom of the crystallizer is provided with a first drain pipe, a second drain pipe and a third drain pipe, the first drain pipe, the second drain pipe and the third drain pipe are respectively connected with the cathode area, the crystallization area and the anode area, and a switch valve is provided at the lower part of the first drain pipe, the second drain pipe and the third drain pipe.

10. A method for removing impurity ions by enhanced crystallization purification under the action of an electric field, characterized in that: The method comprises the device for removing impurity ions by enhanced crystallization purification under the action of an electric field according to claim 9, and further comprises the following steps: S1. Add an appropriate amount of mother solution to be crystallized into the cathode area, crystallization area and anode area in the crystallizer, and ensure that the switch valve is in a closed state before adding the crystallization mother solution; S2, starting the first heat exchange medium supply system so that the cooling liquid is continuously introduced into the hollow interlayer cavity, and starting the second heat exchange medium supply system so that the cooling liquid is continuously introduced into each crystallization tube; the temperature of the cooling liquid supplied by the second heat exchange medium supply system is 10-30° C. lower than the initial crystallization temperature of the mother liquid to be crystallized; S3. While the cooling liquid is continuously introduced into the crystallization tube, the changing state of the periphery of the crystallization tube is constantly observed. When a layer of crystals appears on the side wall of the crystallization tube, the second heat exchange medium supply system is turned off. S4, after the second heat exchange medium supply system is turned off, the first heat exchange medium supply system is controlled so that the mother liquid to be crystallized in the crystallizer is cooled down at a certain cooling rate, and the crystallization mother liquid is continuously crystallized during the continuous cooling process; at the same time, after the second heat exchange medium supply system is turned off, the DC power supply is powered on the anode plate and the cathode plate; S5, after the crystallization process continues for a certain period of time, the first heat exchange medium supply system is turned off, and at the same time, the power supply to the cathode plate and the anode plate is turned off; S6, all the switch valves are opened to discharge the remaining crystallization mother liquor from the crystallizer. After the crystallization mother liquor is discharged, the washing liquid supply system is started to simultaneously fill the washing liquid into the plurality of filling areas. The washing liquid flows into the crystals on the side wall of the crystallization tube through the washing liquid inlet. After the crystals on the crystallization tube are continuously washed with the washing liquid for a certain period of time, the washing operation of the crystals is stopped. During the continuous introduction of the washing liquid into the filling area, the washing liquid in the filling area is allowed to completely submerge the washing liquid inlet in the area and continue for a certain period of time. S7, after the crystal washing operation is completed, the middle switch valve is closed, and then the second heat exchange medium supply system is started, so that the heating liquid is continuously introduced into the crystallization tube, and the temperature of the heating liquid is 3-10°C higher than the melting point of the crystal; After the heating liquid is introduced for a certain period of time, the crystals on the crystallization tube fall off the crystallization tube and fall into the bottom of the crystallizer; S8. After all the crystals fall off the crystallization tube, the second heat exchange medium supply system is turned off, and then the first heat exchange medium supply system is started, so that the first heat exchange medium supply system continuously passes heating liquid into the hollow interlayer cavity, and the temperature of the heating liquid is 10-30°C higher than the melting point of the crystal; after the crystal is completely melted, the operation of the second heat exchange medium supply system is stopped, and then the middle switch valve is opened to collect the melted crystallization liquid, thereby completing the crystallization purification.

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