A method and device for preparing vinylene carbonate

Abstract

The invention relates to a method for preparing vinylene carbonate and a preparation device thereof. The method comprises the following steps: S1, mixing vinylene carbonate and dimethyl carbonate in a mixing kettle at a mass volume ratio of 42kg-48kg:100L under a nitrogen environment to obtain a mixed solution; S2, adding 2,4-di-tert-butylphenol into a reaction kettle, adding the mixed solution obtained in S1 into the reaction kettle at a corresponding flow rate, slowly adding triethylamine into the reaction kettle to participate in the reaction, controlling the mass volume ratio of vinylene carbonate and triethylamine to be 0.75kg-0.80kg:1L, and controlling the temperature to be 40-55 DEG C; S3, heating to 55-70 DEG C, continuously reacting for 16-20h, and performing solid-liquid separation after the reaction is completed to obtain a vinylene carbonate crude solution; and S4, distilling and purifying the vinylene carbonate crude solution to obtain high-purity vinylene carbonate.

Description

Technical Field

[0001] The invention relates to the field of vinylene carbonate preparation, and in particular to a method for preparing vinylene carbonate and a preparation device thereof. Background Art

[0002] With the popularization of electric vehicles and the rapid development of electronic related industries, vinylene carbonate is an important additive in lithium battery electrolytes. It can undergo electrochemical reactions on the negative electrode surface during the initial charge and discharge of lithium batteries to form a solid electrolyte interface film (SEI film), effectively inhibiting the embedding of solvent molecules and the gas expansion of lithium batteries, thereby improving battery life. It is currently the most widely used and best performing electrolyte additive.

[0003] Existing vinylene carbonate is generally prepared by chlorination reaction and dechlorination reaction of vinylene carbonate. For example, the patent document with application number CN202210288294.7 discloses a method for preparing vinylene carbonate, wherein vinylene carbonate is used as a raw material and dimethyl carbonate is used as a solvent, chlorine is introduced and, under ultraviolet light, a free radical reaction is performed to generate monochloroethylene carbonate, and then triethylamine and other acid binding agents are used to obtain vinylene carbonate by bimolecular elimination reaction. Since the reaction between monochloroethylene carbonate and triethylamine is violent and generates a large amount of heat and precipitate, the target product vinylene carbonate is heat-sensitive and easily decomposed by heat. Existing methods or equipment for preparing vinylene carbonate have technical problems such as long reaction time and low yield.

[0004] The purpose of the present invention is to design a method and a device for preparing vinylene carbonate in view of the problems existing in the prior art. Summary of the invention

[0005] In view of the problems existing in the above-mentioned prior art, the present invention provides a method for preparing vinylene carbonate and a preparation device thereof, which can effectively solve at least one problem existing in the above-mentioned prior art.

[0006] The technical solution of the present invention is:

[0007] A method for preparing vinylene carbonate comprises the following steps:

[0008] S1, mixing ethylene chlorocarbonate and dimethyl carbonate in a mixing kettle at a mass volume ratio of 42kg-48kg:100L under a nitrogen environment to obtain a mixed solution;

[0009] S2, add 2,4-di-tert-butylphenol into the reactor, add the mixed solution obtained in S1 into the reactor at a corresponding flow rate, slowly add triethylamine into the reactor to participate in the reaction, control the mass volume ratio of ethylene chlorocarbonate to triethylamine to be 0.75kg-0.80kg:1L, and control the temperature to be 40-55°C;

[0010] S3, heating to 55-70°C, reacting continuously for 16-20 hours, and performing solid-liquid separation after the reaction is completed to obtain a crude vinylene carbonate solution;

[0011] S4, purifying the crude vinylene carbonate liquid by distillation to obtain high-purity vinylene carbonate.

[0012] Furthermore, in S4, the distillation environment is: negative pressure -0.001 to -0.0009 MPa, temperature control is 50 to 65°C, and reflux ratio is 1:7 to 9.

[0013] Furthermore, in S3, the obtained solid is washed with dimethyl carbonate for multiple times and filtered, and the obtained washing liquid is purified by distillation to obtain high-purity vinylene carbonate.

[0014] A vinylene carbonate preparation device is further provided, comprising:

[0015] A mixing kettle is used to mix ethylene chlorocarbonate and dimethyl carbonate in a mass volume ratio of 42kg-45kg:100L in a mixing kettle under a nitrogen environment;

[0016] A high-pressure plunger pump, connected to the discharge end of the mixing kettle, is used to output the mixed liquid obtained in the mixing kettle at a corresponding flow rate;

[0017] A reaction kettle, connected to the discharge end of the high-pressure plunger pump, for slowly adding triethylamine to participate in the reaction;

[0018] The distillation tower is connected to the discharge end of the reactor and is used for distilling and purifying the vinylene carbonate crude liquid to obtain high-purity vinylene carbonate.

[0019] Furthermore, the reactor comprises:

[0020] A reaction kettle body, the upper part of which is sealed with a corresponding sealing cover, and the sealing cover is provided with a feeding mechanism for adding the reaction raw materials into the reaction kettle body respectively;

[0021] The stirring mechanism comprises a stirring tube rotatably mounted on the cover, the stirring tube extending downward into the reactor body, a plurality of corresponding stirring blades fixedly mounted at intervals in the middle of the stirring tube, and a corresponding driving shaft rotatably sleeved in the middle of the stirring tube through a group of mounting bearings arranged at different heights;

[0022] A driving mechanism, used to drive the stirring tube and the driving shaft to rotate respectively, wherein the rotation speed of the driving shaft is greater than the rotation speed of the stirring tube;

[0023] The solid storage mechanism comprises an isolation container fixedly connected to the middle of the bottom of the reactor body, at least one material passing hole is arranged on the side wall of the isolation container, the top of the isolation container is upwardly connected to a storage cylinder body provided with a plurality of filtering holes, the upper part of the storage cylinder body is sleeved on the lower side of the stirring pipe member in a spaced state, the bottom of the driving shaft member extends to the lower side of the storage cylinder body and is fixedly connected to a corresponding spiral feeding plate, and an axial flow impeller located in the storage cylinder body is fixedly connected to the driving shaft member on the upper side of the spiral feeding plate;

[0024] The discharge mechanism comprises a discharge pipe connected to the reactor body, a corresponding discharge valve is fixedly installed on the discharge pipe, and a feed end of the discharge pipe is connected to the isolation container, in which a corresponding plug body can be lifted and lowered; when the plug body is upwardly blocked on the bottom side of the storage cylinder body, the material in the reaction process continuously enters the storage cylinder body through the upper end of the storage cylinder body driven by the axial flow impeller, wherein the liquid material is continuously discharged along the filter holes on the storage cylinder body, and the solid material enters the bottom side of the storage cylinder body for storage; after the reaction is completed, part of the liquid material with less solid content is pumped out to the external solid-liquid separation equipment in advance for rapid solid-liquid separation; then, the discharge valve is closed, the plug body is downwardly spaced from the bottom of the storage cylinder body, and the solid material stored in the storage cylinder body is discharged through the gap between the plug body and the storage cylinder body and mixed with the liquid material in the reactor body; finally, the mixed material is pumped out to the external solid-liquid separation equipment for solid-liquid separation.

[0025] Furthermore, along the stirring tube outward, the bottom side of the stirring blade is tilted upward, and the bottom of the stirring blade is folded upward to form a guide portion with an arc-shaped cross-section, and a plurality of corresponding liquid permeable holes are evenly distributed on the stirring blade.

[0026] Furthermore, along the rotation direction of the stirring tube, the bottom side of the stirring blade is tilted backward, and the stirring tube is provided with corresponding guide holes at positions corresponding to the bottom of the stirring blade, and the mounting bearing at the bottom is fixedly installed in the stirring tube on the upper side of the guide hole.

[0027] Furthermore, the distillation tower comprises:

[0028] The tower body is provided with a heavy component reflux port, a steam return port, and a liquid outlet at the bottom of the tower body, a light component reflux port, a steam return port, and a liquid outlet at the top of the tower body, and a raw material inlet is provided in the middle of the tower body;

[0029] A condenser connected to the steam outlet, used for condensing the gas phase flow at the top of the tower body to form a reflux liquid;

[0030] A reflux tank, connected between the condenser and the light component reflux port, for storing and refluxing the reflux liquid;

[0031] A reboiler connected between the heavy component reflux port and the steam return port, and used for heating and vaporizing the heavy component liquid at the bottom of the tower body;

[0032] The heat exchange layer is multiple in number and is arranged longitudinally and fixedly in the tower body, comprising a rigid outer ring and a flexible spherical surface arranged on the rigid outer ring, a connecting groove is arranged at the center of the flexible spherical surface, a plurality of heat exchange plates are arranged on the upper surface of the flexible spherical surface, and a plurality of liquid drop holes are arranged on the flexible spherical surface;

[0033] A driving device is arranged in the tower body, the driving device comprises a connecting shaft and a driving member, the connecting shaft penetrates and connects all the connecting grooves, the driving member drives the center of the flexible spherical surface to turn up or down through the connecting shaft, after the flexible spherical surface turns up, the plurality of heat exchange plates are in a divergent state, and after the flexible spherical surface turns down, the plurality of heat exchange plates are in a convergent state;

[0034] A temperature sensor is arranged at the bottom of the tower body;

[0035] The control system obtains data from the temperature sensor and is used to control the driving member to drive the center of the flexible spherical surface to turn up or down according to the data from the temperature sensor.

[0036] Furthermore, the heat exchange plates are arranged in a multi-circle circular array with the center of the flexible spherical surface, the heat exchange plates are arc sheet structures, the inner arc surface of the heat exchange plates faces the connecting groove, the heat exchange plates in the same circle are arranged at equal angles, and the heat exchange plates in different circles are staggered.

[0037] Furthermore, the downcomers are arranged at intervals between the heat exchange plates in the same circle.

[0038] Therefore, the present invention provides the following effects and / or advantages:

[0039] The present application provides a method for preparing vinylene carbonate, which realizes continuous production of vinylene carbonate and improves the production efficiency and yield of vinylene carbonate through reaction efficiency control, a high-efficiency self-cleaning filtration system for separating reaction mother liquor and solid by-products, design of a distillation tower and reflux control, raw material recovery and back-end processing technology.

[0040] The reactor provided by the present invention is provided with a drive shaft connected to the middle of the stirring tube by a group of bearings installed in the present invention, and the stirring tube and the drive shaft are driven respectively by the driving mechanism to control the rotation speed of the drive shaft to be greater than the rotation speed of the stirring tube, so as to realize the high-speed rotation of the axial flow impeller under the condition of normal stirring rate, and then cooperate with the solid storage mechanism as a whole to continuously draw the materials in the reaction process into the storage cylinder through the upper end of the storage cylinder. In this process, the liquid material is continuously discharged along the filter holes on the storage cylinder, and the solid material enters the bottom side of the storage cylinder for storage. After the reaction is completed, part of the liquid material with less solid content is pumped out to the external solid-liquid separation equipment for rapid solid-liquid separation; subsequently, the plug body is controlled to move downward so that it is spaced from the bottom of the storage cylinder, and the rotation of the stirring tube and the drive shaft is maintained, so that the solid material stored in the storage cylinder can be discharged and mixed with the liquid material in the reactor body; finally, the mixed material is pumped out to the external solid-liquid separation equipment for solid-liquid separation.

[0041] To achieve: temporarily storing part of the solid materials in the reaction products, so that the liquid materials with low solid content can be discharged for rapid solid-liquid separation; subsequently, the temporarily stored solid mixture is mixed with the remaining liquid materials, and the mixed materials with greatly increased solid content are pumped into the filtration system to quickly separate the liquid materials with a smaller proportion, thereby effectively and significantly improving the solid-liquid separation effect and solid-liquid separation efficiency.

[0042] Along the stirring tube outward, the bottom side of the stirring blade of the present invention is arranged to be tilted upward, and the bottom of the stirring blade is folded upward to provide a guide portion with an arc-shaped cross-section, and a plurality of corresponding liquid-permeable holes are evenly distributed on the stirring blade; and along the rotation direction of the stirring tube, the bottom side of the stirring blade is arranged to be tilted backward. The most important thing is that the stirring tube is respectively provided with corresponding guide holes at positions corresponding to the bottom of the stirring blade, and the mounting bearing located at the bottom is fixedly installed in the stirring tube on the upper side of the guide hole.

[0043] The distillation tower provided by the present invention changes the structure of the traditional heat exchange layer with a fixed setting and fixed shape, and improves the heat exchange layer into a structure that can be flipped up and down, thereby driving the heat exchange plate to diverge or converge. The heat exchange plate in the divergent state can make it easier for steam and reflux liquid to pass through the downcomer holes to accelerate heat exchange, and the heat exchange plate in the convergent state can make it difficult for steam and reflux liquid to pass through the downcomer holes to hinder heat exchange. By changing the heat exchange rate of the heat exchange layer, the temperature at the bottom of the tower can be controlled, so that the temperature at the bottom of the tower can be better maintained in a good temperature range, preventing overheating and decomposition of vinylene carbonate, and ensuring that the steam at the bottom of the tower has enough heat energy to rise to the top of the tower.

[0044] The present invention sets the structure of the heat exchange plate to an arc sheet shape and sets the orientation of the heat exchange plate, so that a certain gap is still left after the heat exchange plates in a convergent state are stacked, allowing a small amount of steam and reflux liquid to pass through.

[0045] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0046] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a structural diagram of embodiment 4 of the present invention.

[0048] Figure 2 This is a schematic diagram of the structure of a reactor provided in Example 4 of the present invention.

[0049] Figure 3 This is a cross-sectional view of a reactor provided in Example 4 of the present invention.

[0050] Figure 4 It is a schematic diagram of the assembly of the stirring blades and solid storage mechanism of the reactor.

[0051] Figure 5 Schematic diagram of the structure of the stirring blade of the reactor.

[0052] Figure 6 This is a schematic diagram of the structure of a distillation tower provided in Example 4 of the present invention.

[0053] Figure 7 It is a structural schematic diagram of the heat exchange layer in the flipped-up state.

[0054] Figure 8 It is a structural schematic diagram of the heat exchange layer in the folded down state.

[0055] Fig. 9 It is a schematic structural diagram of a driving device according to a fourth embodiment of the present invention.

[0056] Fig.10 This is a schematic diagram of the structure of a distillation tower provided in Example 5 of the present invention.

[0057] Fig.11 It is a schematic structural diagram of a driving device according to a fifth embodiment of the present invention.

[0058] Description of reference numerals:

[0059] Mixing kettle 4, high pressure plunger pump 3, reaction kettle 2, distillation tower 1;

[0060] Reactor body 201, cover 202, feeding mechanism 203, feeding pipe 2031, dripping coil 2032, stirring mechanism 204, stirring pipe 2041, stirring blade 2042, guide part 20421, mounting bearing 205, drive shaft 206, driving mechanism 207, large gear 2071, small gear 2072, variable speed double gear 2073, gear drive motor 2074, solid storage mechanism 208, isolation container 2081, storage cylinder 2082, spiral Feeding plate 2083, axial flow impeller 2084, material passing hole 209, discharge mechanism 2010, discharge pipe 20101, discharge valve 20102, plug body 2011, guide hole 2012, dripping liquid inlet valve 2013, feed valve 2014, lifting drive mechanism 2015, plug body drive motor 20151, drive screw 20152, guide column 2016, heat exchange jacket 2017, heat exchange medium inlet pipe 2018, heat exchange medium outlet pipe 2019, support foot 2020;

[0061] Tower body 11, raw material inlet 111, heavy component reflux port 112, steam return port 113, liquid outlet 114, light component reflux port 115, steam outlet 116, condenser 12, reflux tank 13, reboiler 14, heat exchange layer 15, rigid outer ring 151, flexible spherical surface 152, heat exchange plate 153, downcomer 154, drive device 16, connecting shaft 161, drive member 162, rotating nut 163, connecting ring 164, isolation layer 17. DETAILED DESCRIPTION

[0062] In order to facilitate understanding by those skilled in the art, the structure of the present invention is further described in detail with reference to the embodiments in conjunction with the accompanying drawings:

[0063] A method for preparing vinylene carbonate comprises the following steps:

[0064] S1, mixing ethylene chlorocarbonate and dimethyl carbonate in a mixing kettle at a mass volume ratio of 42kg-48kg:100L under a nitrogen environment to obtain a mixed solution;

[0065] S2, add 2,4-di-tert-butylphenol into the reactor, add the mixed solution obtained in S1 into the reactor at a corresponding flow rate, slowly add triethylamine into the reactor to participate in the reaction, control the mass volume ratio of ethylene chlorocarbonate to triethylamine to be 0.75kg-0.80kg:1L, and control the temperature to be 40-55°C;

[0066] S3, heating to 55-70°C, reacting continuously for 16-20h, performing solid-liquid separation after the reaction is completed to obtain a crude vinylene carbonate liquid, washing the obtained solid with dimethyl carbonate for multiple times, filtering, and purifying the obtained washing liquid by distillation to obtain high-purity vinylene carbonate;

[0067] S4, distilling and purifying the vinylene carbonate crude liquid to obtain high-purity vinylene carbonate, the distillation environment is: negative pressure -0.001 to -0.0009 MPa, temperature control is 50 to 65° C., and reflux ratio is 1:7 to 9.

[0068] Embodiment 1

[0069] 180kg of industrial pure ethylene chlorocarbonate as raw material and 390L of dimethyl carbonate as solvent were pumped into a carbon steel tank mixer through a plunger feed pump for mixing. Before feeding, the air was replaced with nitrogen through a nitrogen replacement device. 9kg of polymerization inhibitor 2,4-di-tert-butylphenol was first added to the reactor, and then the mixed liquid of the raw material ethylene chlorocarbonate and the solvent dimethyl carbonate was pumped into the reactor through a high-pressure plunger pump at 1.0Mpa, 5kg / min. The stirring was turned on, and the temperature of the reactor was raised to 45°C. Then 240L of triethylamine solution was added. Add to the reactor at a rate of 5.5L / min, and nitrogen protection is performed during the addition process. The temperature of the reaction system is 45°C during the addition. After the addition is completed, the temperature of the reaction system is raised to 60°C, and the reaction is continued for 16 hours. After the reaction is completed, enter the filtration system for filtration, and keep the temperature of the filtration system at 55°C. Then, use 100L of dimethyl carbonate to wash the filtered solid slag, keep the temperature at 60°C, keep warm for 5min, and then add 100L of dimethyl carbonate, keep the temperature at 65°C, and wash and filter for the second time. After the filtration and washing, the reaction liquid enters the distillation tower for distillation, and the pressure of the distillation tower is -0.001Mpa. The temperature of the tower bottom is 60°C, the top temperature of the tower is controlled to be 21-23°C, and the reflux ratio is 1 / 8, and 53.30kg of high-purity vinylene carbonate is obtained. The yield is 50.1% calculated based on chloroethylene carbonate.

[0070] Embodiment 2

[0071] 190 kg of raw material ethylene chlorocarbonate and 400 L of solvent dimethyl carbonate were pumped into a carbon steel tank mixer through a plunger feed pump for mixing. Before feeding, the air was replaced with nitrogen through a nitrogen replacement device. 9.5 kg of polymerization inhibitor 2,4-di-tert-butylphenol was first added to the reactor, and then the mixed liquid of raw material ethylene chlorocarbonate and solvent dimethyl carbonate was pumped into the reactor through a high-pressure plunger pump at 1.0 MPa, 5 kg / min. Stirring was started, and the temperature of the reactor was raised to 45°C. Then 250 L of triethylamine solution was added. Add to the reactor at a rate of 5.5L / min, and nitrogen protection is performed during the addition process. The temperature of the reaction system during the addition is 45°C. After the addition is completed, the temperature of the reaction system is raised to 60°C, and the reaction is continued for 17 hours. After the reaction is completed, enter the filtration system for filtration, and keep the temperature of the filtration system at 55°C. Then use 100L of dimethyl carbonate to wash the filtered solid slag, keep the temperature at 60°C, keep warm for 5min, and then add 100L of dimethyl carbonate, keep the temperature at 65°C, and wash and filter for the second time. After the filtration and washing, the reaction liquid enters the distillation tower for distillation, and the pressure of the distillation tower is -0.001Mpa. The temperature of the tower bottom is 60°C, the tower top temperature is controlled to be 21-22°C, and the reflux ratio is 1 / 8, and 60.08kg of high-purity vinylene carbonate is obtained, and the yield calculated by chloroethylene carbonate is 53.8%.

[0072] Embodiment 3

[0073] 200 kg of raw material ethylene chlorocarbonate and 420 L of solvent dimethyl carbonate were pumped into a carbon steel tank mixer through a plunger feed pump for mixing. Before feeding, the air was replaced with nitrogen through a nitrogen replacement device. 10 kg of polymerization inhibitor 2,4-di-tert-butylphenol was first added to the reactor, and then the mixed solution of raw material ethylene chlorocarbonate and solvent dimethyl carbonate was pumped into the reactor through a high-pressure plunger pump at 1.0 MPa, 5 kg / min. Stirring was started, and the temperature of the reactor was raised to 48°C. Then 250 L of triethylamine solution was added at 1.0 MPa and 5 kg / min. The reaction kettle was added at a rate of 5.5L / min, and nitrogen protection was performed during the addition process. The temperature of the reaction system during the addition was 48°C. After the addition was completed, the temperature of the reaction system was raised to 62°C, and the reaction was continued for 18 hours. After the reaction was completed, it entered the filtration system for filtration, and the temperature of the filtration system was maintained at 55°C. Then, 100L of dimethyl carbonate was used to wash the filtered solid residue, and the temperature was maintained at 60°C for 5 minutes, and then 100L of dimethyl carbonate was used to maintain the temperature at 65°C for the second washing and filtration. After the filtration and washing, the reaction liquid entered the distillation tower for distillation, and the pressure of the distillation tower was -0.001Mpa. The temperature of the tower bottom was 60°C, the tower top temperature was controlled at 21-22°C, the reflux ratio was 1 / 8, and 63.34kg of high-purity vinylene carbonate was obtained, and the yield was 53.9% calculated based on chloroethylene carbonate.

[0074] Through Examples 1 to 3, it can be seen that the yield of vinylene carbonate obtained by the reaction conditions provided in Example 3 is the highest.

[0075] Embodiment 4

[0076] Further providing a preparation device for vinylene carbonate, comprising: referring to Figure 1 ,

[0077] A mixing kettle 4 is used to mix ethylene chlorocarbonate and dimethyl carbonate in a mass volume ratio of 42kg to 48kg:100L in a mixing kettle under a nitrogen environment;

[0078] A high-pressure plunger pump 3 is connected to the discharge end of the mixing kettle 4 and is used to output the mixed liquid obtained in the mixing kettle at a corresponding flow rate;

[0079] Reactor 2, connected to the discharge end of the high-pressure plunger pump 3, for slowly adding triethylamine to participate in the reaction;

[0080] The distillation tower 1 is connected to the discharge end of the reactor 2 and is used for distilling and purifying the vinylene carbonate crude liquid to obtain high-purity vinylene carbonate.

[0081] Specifically, the reactor 2 includes: Figure 2-5 ,

[0082] The reactor body 201 is sealed with a corresponding cover 202 on the upper part, and the cover 202 is provided with a feeding mechanism 203 for adding the reaction raw materials into the reactor body 201;

[0083] The stirring mechanism 204 comprises a stirring tube 2041 rotatably mounted on the cover 202, the stirring tube 2041 extending downward into the reactor body 201, a plurality of corresponding stirring blades 2042 are fixedly mounted at intervals in the middle of the stirring tube 2041, and a corresponding driving shaft 206 is rotatably sleeved in the middle of the stirring tube 2041 through a group of mounting bearings 205 arranged at different heights;

[0084] The driving mechanism 207 is used to drive the stirring tube 2041 and the driving shaft 206 to rotate respectively, and the rotation speed of the driving shaft 206 is greater than the rotation speed of the stirring tube 2041;

[0085] The solid storage mechanism 208 comprises an isolation container 2081 fixedly connected to the middle of the bottom of the reactor body 201, at least one material passing hole 209 is arranged on the side wall of the isolation container 2081, the top of the isolation container 2081 is upwardly connected to a storage cylinder 2082 provided with a plurality of filter holes, the upper part of the storage cylinder 2082 is sleeved on the lower side of the stirring tube 2041 in a spaced state, the bottom of the driving shaft 206 extends to the lower side of the storage cylinder 2082 and is fixedly connected to a corresponding spiral feeding plate 2083, and an axial flow impeller 2084 located in the storage cylinder 2082 is fixedly connected to the driving shaft 206 on the upper side of the spiral feeding plate 2083;

[0086] The discharge mechanism 2010 comprises a discharge pipe 20101 connected to the reactor body 201, a corresponding discharge valve 20102 is fixedly installed on the discharge pipe 20101, the feed end of the discharge pipe 20101 is connected to the isolation container 2081, and a corresponding plug 2011 is installed in the isolation container 2081 in a liftable manner; when the plug 2011 is upwardly blocked on the bottom side of the storage cylinder 2082, the materials in the reaction process continuously enter the storage cylinder 2082 through the upper end of the storage cylinder 2082 under the drive of the axial flow impeller 2084, wherein the liquid materials continuously flow along the storage cylinder 2082. The liquid is discharged through the filter hole on the top, and the solid material enters the bottom side of the storage cylinder 2082 for storage; after the reaction is completed, some liquid materials with low solid content are pumped out to the external solid-liquid separation equipment for rapid solid-liquid separation; then, the discharge valve 20102 is closed, and the plug body 2011 moves downward and is spaced apart from the bottom of the storage cylinder 2082, and the solid material stored in the storage cylinder 2082 is discharged through the gap between the plug body 2011 and the storage cylinder 2082 and mixed with the liquid material in the reactor body 201; finally, the mixed material is pumped out to the external solid-liquid separation equipment for solid-liquid separation.

[0087] A drive shaft 206 is rotatably sleeved on the middle part of the stirring tube 2041 through a group of mounting bearings 205. The stirring tube 2041 and the drive shaft 206 are driven separately by the driving mechanism 207 to control the rotation speed of the drive shaft 206 to be greater than the rotation speed of the stirring tube 2041, so as to realize the high-speed rotation of the axial flow impeller 2084 under the condition of normal stirring rate, and then cooperate with the solid storage mechanism 208 as a whole to continuously draw the materials in the reaction process into the storage cylinder 2082 through the upper end of the storage cylinder 2082. In this process, the liquid material is continuously discharged along the filter holes on the storage cylinder 2082, and the solid material enters the bottom side of the storage cylinder 2082 for storage. After the reaction is completed, some liquid materials with low solid content are pumped out to external solid-liquid separation equipment for rapid solid-liquid separation; subsequently, the plug body 2011 is controlled to move downward so that it is spaced apart from the bottom of the storage cylinder 2082, and the stirring tube 2041 and the driving shaft 206 are kept rotating, so that the solid material stored in the storage cylinder 2082 can be discharged and mixed with the liquid material in the reactor body 201; finally, the mixed material is pumped out to external solid-liquid separation equipment for solid-liquid separation treatment.

[0088] To achieve: temporarily storing part of the solid materials in the reaction products, so that the liquid materials with low solid content can be discharged for rapid solid-liquid separation; subsequently, the temporarily stored solid mixture is mixed with the remaining liquid materials, and the mixed materials with greatly increased solid content are pumped into the filtration system to quickly separate the liquid materials with a smaller proportion, thereby effectively and significantly improving the solid-liquid separation effect and solid-liquid separation efficiency.

[0089] Along the stirring tube 2041 outward, the bottom side of the stirring blade 2042 is tilted upward, and the bottom of the stirring blade 2042 is folded upward to form a guide portion 20421 with an arc-shaped cross-section, and a plurality of corresponding liquid permeable holes are evenly distributed on the stirring blade 2042.

[0090] Along the rotation direction of the stirring tube 2041, the bottom side of the stirring blade 2042 is tilted backward, and the stirring tube 2041 is provided with corresponding guide holes 2012 at positions corresponding to the bottoms of the stirring blades 2042, and the mounting bearing 205 at the bottom is fixedly installed in the stirring tube 2041 on the upper side of the guide holes 2012.

[0091] The solid materials in the stirring process will be guided by the stirring blade 2042, gathered at the guide part 20421 at the bottom of the stirring blade 2042, and converged to one end of the stirring tube 2041, and finally enter the gap between the stirring tube 2041 and the driving shaft 206 and enter the storage cylinder 2082 of the solid storage mechanism 208, thereby effectively improving the collection effect of the solid materials in the reaction products, which can not only reduce the mixing resistance of the stirring blade 2042, but also increase the storage amount of the solid materials, thereby effectively ensuring the implementation effect of the overall technical solution of the present invention.

[0092] The feeding mechanism 203 comprises a feeding pipe 2031 connected to the cover 202, and a dripping coil 2032 disposed in the reactor body 201 at the lower side of the cover 202. The liquid inlet end of the dripping coil 2032 extends to the outside of the cover 202 and is fixedly installed with a corresponding dripping liquid inlet valve 2013. The feeding pipe 2031 is fixedly installed with a corresponding feeding valve 2014. During the reaction, the polymerization inhibitor 2,4-di-tert-butylphenol, chloroethylene carbonate and dimethyl carbonate mixture are respectively injected into the reactor body 201 through the feeding pipe 2031, and triethylamine is gradually dripped into the reactor body 201 through the dripping hole at the bottom of the dripping coil 2032 to participate in the reaction.

[0093] The driving mechanism 207 comprises a large gear 2071 fixedly connected to the stirring tube 2041, and a small gear 2072 fixedly connected to the driving shaft 206, wherein the large gear 2071 and the small gear 2072 are respectively meshed and connected to a variable speed double gear 2073 arranged in a step shape, and the variable speed double gear 2073 is transmission-connected to the output shaft end of the corresponding gear driving motor 2074. During the driving process, the variable speed double gear 2073 forms meshing transmission with the large gear 2071 and the small gear 2072 respectively, so as to increase the rotation speed of the driving shaft 206 and reduce the rotation speed of the stirring tube 2041, thereby effectively achieving a high-speed rotation of the axial flow impeller 2084 under the condition of normal stirring speed.

[0094] The plug body 2011 is driven by a corresponding lifting drive mechanism 2015, which includes a plug body driving motor 20151 and a driving screw 20152 that is transmission-connected to the output shaft end of the plug body driving motor 20151. The middle bottom side of the plug body 2011 is transmission-connected to the driving screw 20152 by a threaded connection. A group of corresponding guide columns 2016 are fixedly connected upward to the bottom side of the reactor body 201, and guide holes that are compatible with the guide columns 2016 are provided on both sides of the plug body 2011.

[0095] A corresponding heat exchange jacket 2017 is fixedly installed on the outer side of the reactor body 201, and a heat exchange medium inlet pipe 2018 is connected to the lower side of the heat exchange jacket 2017, and a heat exchange medium outlet pipe 2019 is connected to the upper side of the heat exchange jacket 2017.

[0096] The reactor body 201 is supported and installed by a plurality of corresponding legs 2020. A group of the mounting bearings 205 are sealed and waterproof bearings. The upper end of the plug body 2011 is arranged in a truncated cone shape.

[0097] Specifically, the distillation tower 1 comprises: Figure 6-9 ,

[0098] A tower body 11, wherein a heavy component reflux port 112, a steam return port 113, and a liquid outlet 114 are disposed at the bottom of the tower body 11, a light component reflux port 115 and a steam outlet 116 are disposed at the top of the tower body, and a raw material inlet 111 is disposed in the middle of the tower body 11;

[0099] A condenser 12, connected to the steam outlet 116, for condensing the gas phase flow at the top of the tower body 11 to form a reflux liquid;

[0100] A reflux tank 13, connected between the condenser 12 and the light component reflux port 115, for storing and refluxing the reflux liquid;

[0101] The reboiler 14 is connected between the heavy component reflux port 112 and the steam return port 113 and is used to heat and vaporize the heavy component liquid at the bottom of the tower body 11;

[0102] In this embodiment, the principle of the distillation tower is to use the reboiler 14 at the bottom to continuously heat and vaporize the liquid at the bottom of the tower, so that the liquid vaporizes and flows to the top of the tower. The condenser 12 condenses the gas phase flow at the top of the tower to form a reflux liquid, and the reflux liquid returns to the top of the tower from the light component reflux port, and the reflux liquid flows downward from the top of the tower. During the downflow of the reflux liquid, the reflux liquid contacts the gas phase flow generated by the reboiler 14, and the gas phase flow exchanges energy with the reflux liquid. The energy in part of the gas phase flow is transferred to the reflux liquid, so that part of the reflux liquid vaporizes in the heat absorption process of the downflow, and part of the gas phase flow loses heat and liquefies in the process of rising. By repeating the above process continuously, the light weight components and low boiling point components in the liquid at the bottom of the tower can be separated to the top of the tower and condensed and stored in the reflux tank 13, thereby achieving a purification effect. The structure and working principle of the condenser 12, the reflux tank 13, the reboiler 14, and the tower body 11 are directly adopted from the prior art and will not be described in detail here. This embodiment is also provided with a negative pressure system (not shown) to form a negative pressure inside the tower body 11, thereby lowering the boiling point of dimethyl carbonate. For example, the tower body is controlled to be in a negative pressure state of -0.001 to -0.0009 MPa, so that the boiling point of dimethyl carbonate is less than 65°C.

[0103] The heat exchange layer 15 is multiple in number and arranged vertically and fixedly in the tower body 11, and includes a rigid outer ring 151 and a flexible spherical surface 152 arranged on the rigid outer ring 151, a connecting groove is arranged at the center of the flexible spherical surface 152, a plurality of heat exchange plates 153 are arranged on the upper surface of the flexible spherical surface 152, and a plurality of liquid drop holes 154 are arranged on the flexible spherical surface 152;

[0104] In this embodiment, the heat exchange layer 15 is fixedly arranged in the tower body 11 at equal intervals by a rigid outer ring 151. The rigid outer ring 151 can be made of a metal ring with an outer layer coated with polytetrafluoroethylene, so that a fixed arrangement structure can be achieved. The flexible spherical surface 152 can be a hemispherical surface or a quarter spherical surface, etc., as long as the flexible spherical surface 152 can achieve the function of turning up or down, and the flexible spherical surface 152 forms a corresponding upwardly arched or downwardly concave structure after turning up or down, and no limitation is made here. When the flexible spherical surface 152 turns up to form an arched structure, such as Figure 2 As shown, at this time, the center of the flexible spherical surface 152 is below the flexible spherical surface 152, and the lower end of the heat exchange plate 153 points to the center of the flexible spherical surface 152 corresponding to this state, so that the heat exchange plate 153 is in a divergent state after the flexible spherical surface 152 is turned up; when the flexible spherical surface 152 is turned down to form a concave structure, as shown in FIG. Figure 3 As shown, at this time, the center of the flexible spherical surface 152 is above the flexible spherical surface 152, and the top of the heat exchange plate 153 points to the center corresponding to the flexible spherical surface 152 in this state, so that the heat exchange plate 153 is in a convergent state after the flexible spherical surface 152 is turned down.

[0105] Since the flexible spherical surface 152 is provided with a plurality of downcomers 154, during the operation of the distillation tower, the vapor generated by the reboiler 14 can move upward from the bottom of the tower through the downcomers 154 of each heat exchange layer 15, while the reflux liquid refluxed from the reflux tank 13 moves downward from the top of the tower through the downcomers 154 of each heat exchange layer 15, and completes heat exchange in each heat exchange layer 15, so that the content of the light components in the raw material gradually increases from the bottom of the tower to the top of the tower, and the content of the heavy components in the raw material gradually increases from the top of the tower to the bottom of the tower. When the flexible spherical surface 152 turns up to form an upper arch structure, the heat exchange plates 153 are in a divergent state. At this time, the distance between the heat exchange plates 153 in the same heat exchange layer 15 increases, which can better open the space above the downcomer hole 154, so that the reflux liquid or steam can pass through the downcomer hole 154 more easily and quickly to complete the heat exchange, so that the temperature of the bottom heat exchange layer 15 is transferred to the upper heat exchange layer 15 more quickly, and the heat generated by the reboiler 14 rises rapidly, so that the temperature of the bottom of the tower gradually decreases; when the flexible spherical surface 152 turns down to form a concave structure, the heat exchange plates 153 in the same layer are in a convergent state. The spacing between the heat exchange plates 153 of the heat exchange layer 15 is reduced, and the heat exchange plates 153 are stacked together to rapidly reduce the space above the downcomer holes 154. It becomes difficult for the steam to rise upward after passing through the downcomer holes 154, and the heat exchange plates 153 in a converging state also form a certain obstruction to the reflux liquid flowing down from the upper layer. It becomes difficult for the reflux liquid to pass through the downcomer holes 154, and it becomes difficult for the reflux liquid above to flow through the surface of the heat exchange plates 153 in a converging state, making it difficult to achieve heat exchange between the reflux liquid and the steam. The heat generated by the reboiler 14 gathers at the bottom of the tower, and the temperature at the bottom of the tower gradually increases.

[0106] The driving device 16 is arranged in the tower body 11, and the driving device includes a connecting shaft 161 and a driving member 162. The connecting shaft 161 penetrates and connects all the connecting grooves. The driving member 162 drives the center of the flexible spherical surface 152 to turn up or down through the connecting shaft 161. After the flexible spherical surface 152 turns up, the plurality of heat exchange plates 153 are in a divergent state. After the flexible spherical surface 152 turns down, the plurality of heat exchange plates 153 are in a convergent state.

[0107] The above describes the structure of the heat exchange layer 15 that can be flipped up or down and deformed to change the heat transfer rate. Next, this embodiment uses the connection relationship between the connecting shaft 161 of the driving device 16 and the flexible spherical surface 152 to drive the center of the flexible spherical surface 152 to flip up or down, thereby realizing the control of the heat exchange rate in the tower body 11.

[0108] A temperature sensor (not shown) is arranged at the bottom of the tower body 11;

[0109] The control system obtains the data of the temperature sensor and is used to control the driving member 162 to drive the center of the flexible spherical surface 152 to turn up or down according to the data of the temperature sensor.

[0110] This embodiment can control the speed of heat transfer upward from the bottom of the tower by setting a temperature sensor and a control system, thereby realizing temperature control of the bottom of the tower. Since vinylene carbonate has a high thermal sensitivity and will decompose rapidly when the temperature is greater than 65°C, this embodiment obtains the temperature of the bottom of the tower through a temperature sensor. If the temperature of the bottom of the tower is greater than the upper temperature threshold, such as 63°C, the flexible spherical surface 152 is driven upward by the driving member 162 to quickly transfer the heat from the bottom of the tower upward to prevent the temperature of the bottom of the tower from continuing to rise above 65°C. When the temperature of the bottom of the tower is less than the lower temperature threshold, such as 50°C, the heat generated by the reboiler 14 at the bottom of the tower makes it difficult for the light components in the reflux liquid to reach the top of the tower. At this time, it is necessary to drive the flexible spherical surface 152 downward by the driving member 162 to accumulate heat at the bottom of the tower and increase the temperature.

[0111] In other embodiments, the upper temperature threshold and the lower temperature threshold may be set according to the negative pressure in the tower body 11 and the specific conditions of impurities in the vinylene carbonate crude liquid.

[0112] Furthermore, the connection groove is provided with a rotating nut 163 , the connection shaft 161 is a screw rod, the rotating nut 163 is driven by the screw rod, the driving member 162 is a rotating motor, and the rotating motor is fixedly arranged on the top of the tower body 1 .

[0113] In this embodiment, the connecting groove is fixedly connected with a rotating nut 163, and a screw assembly is formed by the rotating nut 163 and the screw. During the rotation of the screw, the rotating nut 163 is driven to move upward or downward along the axial direction of the screw, thereby driving the center of the flexible spherical surface 152 to move up and down.

[0114] Furthermore, since the tower body 11 is in a high temperature environment of about 60° C., in order to enable the rotating motor to work normally, the present application may set an isolation layer 17 above the tower body, so that the rotating motor is in a temperature environment where it can work normally.

[0115] Furthermore, the outer surfaces of the rigid outer ring 151 , the flexible spherical surface 152 , and the heat exchange plate 153 are all coated with polytetrafluoroethylene material.

[0116] In this embodiment, the rigid outer ring 151 and the heat exchange plate 153 can be made of corresponding metals, and then the outer surface of the rigid outer ring 151 and the heat exchange plate 153 is coated with polytetrafluoroethylene material. Also, the flexible spherical surface 152 can be made of rubber and then coated with polytetrafluoroethylene material, or the flexible spherical surface 152 is directly formed into a spherical shape by injection molding of polytetrafluoroethylene material, and the thickness of the flexible spherical surface 152 is controlled to achieve good flexibility, so that it can be turned up or down. Polytetrafluoroethylene has good corrosion resistance, high temperature resistance, and stability, and can be used in the process of vinylene carbonate purification.

[0117] Furthermore, the heat exchange plates 153 are arranged in a multi-circle circular array with the center of the flexible spherical surface 152 .

[0118] Furthermore, the heat exchange plates 153 are arc-shaped sheet structures, the inner arc surface of the heat exchange plates 153 faces the connecting groove, the heat exchange plates 153 in the same circle are arranged at equal angles, and the heat exchange plates 153 in different circles are arranged in a staggered manner.

[0119] In this embodiment, the heat exchange plate 153 is a tile-shaped circular arc sheet structure, and the circular arc surface of the heat exchange plate 153 is perpendicular to the flexible spherical surface 152, so that it is divergent or convergent on the flexible spherical surface 152. The inner arc surface of the heat exchange plate 153 faces the connecting groove. The purpose of this is that when the heat exchange plate 153 is in a convergent state, the top of the heat exchange plate 153 of the outer circle is stacked on the top of the heat exchange plate 153 of the inner circle. At this time, the arc sheet structure makes the top of the stacked heat exchange plate 153 still have an opening, which prevents the top of the stacked heat exchange plate 153 from being completely closed, thereby preventing the internal pressure from being too high and generating a strong impact airflow.

[0120] Furthermore, the downcomers 154 are arranged at intervals between the heat exchange plates in the same circle.

[0121] In this embodiment, the heat exchange plates 153 of different circles mentioned above are staggered. Therefore, after the flexible spherical surface 152 is concave, the downcomer holes 154 are just located on the gaps between the heat exchange plates 153, thereby providing a path for the rising steam or the descending reflux liquid to enter the downcomer holes 154, further preventing the downcomer holes 154 from being blocked after the flexible spherical surface 152 is concave.

[0122] Furthermore, the surface of the heat exchange plate 153 is configured as a corrugated surface.

[0123] In this embodiment, the corrugated surface can increase the outer surface area of ​​the heat exchange plate 153, thereby increasing the heat exchange area between steam and reflux liquid and improving the heat exchange efficiency.

[0124] A control method for a distillation tower for preparing vinylene carbonate is further provided, based on the distillation tower for preparing vinylene carbonate, comprising the following steps:

[0125] S1, obtaining data from the temperature sensor;

[0126] S2, when the data of the temperature sensor is greater than the upper limit of the temperature threshold, the driving member 162 is controlled to drive the center of the flexible spherical surface 152 to turn up; when the data of the temperature sensor is less than the lower limit of the temperature threshold, the driving member 162 is controlled to drive the center of the flexible spherical surface 152 to turn down.

[0127] Furthermore, the displacement of the flexible spherical surface 152 driven by the driving member 162 to turn up or down is controlled so that the data of the temperature sensor approaches the middle value between the upper limit of the temperature threshold and the lower limit of the temperature threshold.

[0128] The control method provided in this embodiment can obtain the temperature at the bottom of the tower body 11 and set the upper and lower limits of the temperature threshold, thereby controlling the flexible spherical surface 152 to turn up or down, and then controlling the rate of heat exchange inside the tower body 11, so as to achieve controllable heat exchange rate. Finally, the temperature at the bottom of the distillation tower can be controlled to prevent the temperature at the bottom of the distillation tower from being too high to cause overheating and decomposition of vinylene carbonate, and to ensure that the steam at the bottom of the distillation tower has enough heat energy to rise to the top of the tower to complete the heat exchange.

[0129] Embodiment 5

[0130] The difference between this embodiment and the fourth embodiment is that the structure of the driving device of the distillation tower is different. Figure 10-11 The connecting groove is fixedly connected to the connecting shaft 161, and the driving member 162 includes a telescopic cylinder, which drives the connecting shaft 161 to move up and down.

[0131] This embodiment is different from the fourth embodiment in that the connection groove of the flexible spherical surface 152 is connected to the connecting shaft 161 in a different manner, and the selection of the driving member 162 is different. In this embodiment, a connecting ring 164 can be provided in the connecting groove, and the connecting ring 164 can be fixedly connected to the connecting shaft 161, and the telescopic cylinder can adopt a structure such as an electric cylinder.

[0132] For other structures or working principles of this embodiment, reference may be made to Embodiment 4.

[0133] It should be noted that in the claims, any reference signs placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0134] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0135] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0136] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. A method for preparing vinylene carbonate, characterized in that: The following steps are involved: S1, mixing ethylene chlorocarbonate and dimethyl carbonate in a mixing kettle at a mass volume ratio of 42kg-48kg:100L under a nitrogen environment to obtain a mixed solution; S2, add 2,4-di-tert-butylphenol into the reactor, add the mixed solution obtained in S1 into the reactor at a corresponding flow rate, slowly add triethylamine into the reactor to participate in the reaction, control the mass volume ratio of ethylene chlorocarbonate to triethylamine to be 0.75kg-0.80kg:1L, and control the temperature to be 40-55°C; S3, heating to 55-70°C, reacting continuously for 16-20 hours, and performing solid-liquid separation after the reaction is completed to obtain a crude vinylene carbonate solution; S4, distilling and purifying the vinylene carbonate crude liquid to obtain high-purity vinylene carbonate; In S4, the distillation environment is: negative pressure -0.001~-0.0009Mpa, temperature control is 50~65℃, reflux ratio is 1:7~9; the distillation tower includes: The tower body is provided with a heavy component reflux port, a steam return port, and a liquid outlet at the bottom of the tower body, a light component reflux port, a steam return port, and a liquid outlet at the top of the tower body, and a raw material inlet is provided in the middle of the tower body; A condenser, connected to the steam outlet, for condensing the gas phase flow at the top of the tower body to form a reflux liquid; A reflux tank, connected between the condenser and the light component reflux port, for storing and refluxing the reflux liquid; A reboiler connected between the heavy component reflux port and the steam return port, and used for heating and vaporizing the heavy component liquid at the bottom of the tower body; The heat exchange layer is multiple in number and is arranged longitudinally and fixedly in the tower body, comprising a rigid outer ring and a flexible spherical surface arranged on the rigid outer ring, a connecting groove is arranged at the center of the flexible spherical surface, a plurality of heat exchange plates are arranged on the upper surface of the flexible spherical surface, and a plurality of liquid drop holes are arranged on the flexible spherical surface; A driving device is arranged in the tower body, the driving device comprises a connecting shaft and a driving member, the connecting shaft penetrates and connects all the connecting grooves, the driving member drives the center of the flexible spherical surface to turn up or down through the connecting shaft, after the flexible spherical surface turns up, the plurality of heat exchange plates are in a divergent state, and after the flexible spherical surface turns down, the plurality of heat exchange plates are in a convergent state; A temperature sensor is arranged at the bottom of the tower body; A control system, which obtains data from the temperature sensor and is used to control the driving member to drive the center of the flexible spherical surface to turn up or down according to the data from the temperature sensor; The heat exchange plates are arranged in a multi-circle circular array at the center of the flexible spherical surface, the heat exchange plates are arc sheet structures, the inner arc surface of the heat exchange plates faces the connecting groove, the heat exchange plates in the same circle are arranged at equal angles, and the heat exchange plates in different circles are arranged in a staggered manner; The downcomers are arranged at intervals between the heat exchange plates in the same circle.

2. A method for preparing vinylene carbonate according to claim 1, characterized in that: In S3, the obtained solid is washed several times with dimethyl carbonate and filtered, and the obtained washing liquid is purified by distillation to obtain high-purity vinylene carbonate.

3. A device for preparing vinylene carbonate, characterized in that: include: A mixing kettle is used to mix ethylene chlorocarbonate and dimethyl carbonate in a mass volume ratio of 42kg-45kg:100L in a mixing kettle under a nitrogen environment; A high-pressure plunger pump, connected to the discharge end of the mixing kettle, is used to output the mixed liquid obtained in the mixing kettle at a corresponding flow rate; A reaction kettle, connected to the discharge end of the high-pressure plunger pump, for slowly adding triethylamine to participate in the reaction; A distillation tower connected to the discharge end of the reactor is used to purify the vinylene carbonate crude liquid by distillation to obtain high-purity vinylene carbonate. The distillation tower comprises: The tower body is provided with a heavy component reflux port, a steam return port, and a liquid outlet at the bottom of the tower body, a light component reflux port, a steam return port, and a liquid outlet at the top of the tower body, and a raw material inlet is provided in the middle of the tower body; A condenser, connected to the steam outlet, for condensing the gas phase flow at the top of the tower body to form a reflux liquid; A reflux tank, connected between the condenser and the light component reflux port, for storing and refluxing the reflux liquid; A reboiler connected between the heavy component reflux port and the steam return port, and used for heating and vaporizing the heavy component liquid at the bottom of the tower body; The heat exchange layer is multiple in number and is arranged longitudinally and fixedly in the tower body, comprising a rigid outer ring and a flexible spherical surface arranged on the rigid outer ring, a connecting groove is arranged at the center of the flexible spherical surface, a plurality of heat exchange plates are arranged on the upper surface of the flexible spherical surface, and a plurality of liquid drop holes are arranged on the flexible spherical surface; A driving device is arranged in the tower body, the driving device comprises a connecting shaft and a driving member, the connecting shaft penetrates and connects all the connecting grooves, the driving member drives the center of the flexible spherical surface to turn up or down through the connecting shaft, after the flexible spherical surface turns up, the plurality of heat exchange plates are in a divergent state, and after the flexible spherical surface turns down, the plurality of heat exchange plates are in a convergent state; A temperature sensor is arranged at the bottom of the tower body; A control system, which obtains data from the temperature sensor and is used to control the driving member to drive the center of the flexible spherical surface to turn up or down according to the data from the temperature sensor; The heat exchange plates are arranged in a multi-circle circular array at the center of the flexible spherical surface, the heat exchange plates are arc sheet structures, the inner arc surface of the heat exchange plates faces the connecting groove, the heat exchange plates in the same circle are arranged at equal angles, and the heat exchange plates in different circles are arranged in a staggered manner; The downcomers are arranged at intervals between the heat exchange plates in the same circle.

4. A vinylene carbonate preparation device according to claim 3, characterized in that: The reactor comprises: A reaction kettle body, the upper part of which is sealed with a corresponding sealing cover, and the sealing cover is provided with a feeding mechanism for adding the reaction raw materials into the reaction kettle body respectively; The stirring mechanism comprises a stirring tube rotatably mounted on the cover, the stirring tube extending downward into the reactor body, a plurality of corresponding stirring blades fixedly mounted at intervals in the middle of the stirring tube, and a corresponding driving shaft rotatably sleeved in the middle of the stirring tube through a group of mounting bearings arranged at different heights; A driving mechanism, used to drive the stirring tube and the driving shaft to rotate respectively, wherein the rotation speed of the driving shaft is greater than the rotation speed of the stirring tube; The solid storage mechanism comprises an isolation container fixedly connected to the middle of the bottom of the reactor body, at least one material passing hole is arranged on the side wall of the isolation container, the top of the isolation container is upwardly connected to a storage cylinder body provided with a plurality of filtering holes, the upper part of the storage cylinder body is sleeved on the lower side of the stirring pipe member in a spaced state, the bottom of the driving shaft member extends to the lower side of the storage cylinder body and is fixedly connected to a corresponding spiral feeding plate, and an axial flow impeller located in the storage cylinder body is fixedly connected to the driving shaft member on the upper side of the spiral feeding plate; The discharge mechanism comprises a discharge pipe connected to the reactor body, a corresponding discharge valve is fixedly installed on the discharge pipe, and a feed end of the discharge pipe is connected to the isolation container, in which a corresponding plug body can be lifted and lowered; when the plug body is upwardly blocked on the bottom side of the storage cylinder body, the material in the reaction process continuously enters the storage cylinder body through the upper end of the storage cylinder body driven by the axial flow impeller, wherein the liquid material is continuously discharged along the filter holes on the storage cylinder body, and the solid material enters the bottom side of the storage cylinder body for storage; after the reaction is completed, part of the liquid material with less solid content is pumped out to the external solid-liquid separation equipment in advance for rapid solid-liquid separation; then, the discharge valve is closed, the plug body is downwardly spaced from the bottom of the storage cylinder body, and the solid material stored in the storage cylinder body is discharged through the gap between the plug body and the storage cylinder body and mixed with the liquid material in the reactor body; finally, the mixed material is pumped out to the external solid-liquid separation equipment for solid-liquid separation.

5. A vinylene carbonate preparation device according to claim 4, characterized in that: Along the stirring tube outward, the bottom side of the stirring blade is tilted upward, and the bottom of the stirring blade is folded upward to form a guide portion with an arc-shaped cross-section, and a plurality of corresponding liquid permeable holes are evenly distributed on the stirring blade.

6. The device for preparing vinylene carbonate according to claim 5, characterized in that: Along the rotation direction of the stirring tube, the bottom side of the stirring blade is tilted backward, and the stirring tube is provided with corresponding guide holes at positions corresponding to the bottom of the stirring blade, and the mounting bearing at the bottom is fixedly installed in the stirring tube on the upper side of the guide hole.

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