A device for preparing dimethylaminoethyl acrylate

Abstract

The present invention relates to the technical field of dimethylaminoethyl acrylate preparation devices, and in particular to a device for preparing dimethylaminoethyl acrylate. A system for preparing dimethylaminoethyl acrylate comprises a reactor and a distillation tower from bottom to top, and the distillation tower comprises a stripping unit and a rectification unit from bottom to top; the reactor is used to contain a reaction liquid, and the reactor is provided with a heating device, and the heating device is used to heat the reactor to react the reactants in the reaction liquid and evaporate the reaction liquid; the first mixed gas formed by the evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence, and the substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the gas is discharged from the rectification unit. An embodiment of the present invention provides a device for preparing dimethylaminoethyl acrylate, which can perform polymerization reaction and distillation purification.

Description

Technical Field

[0001] The invention relates to the technical field of dimethylaminoethyl acrylate preparation devices, and in particular to a device for preparing dimethylaminoethyl acrylate. Background Art

[0002] The current main process for producing dimethylaminoethyl acrylate is to carry out esterification reaction with dimethylaminoethanol and methyl acrylate as raw materials under the condition of dibutyl oxide as the main catalyst. However, methanol is produced as a by-product during the reaction, which needs to be continuously removed by distillation during the reaction.

[0003] In the related art, when preparing dimethylaminoethyl acrylate, multiple devices such as a reaction kettle, a distillation kettle, and a distillation tower are required, which is costly and occupies a large space.

[0004] Therefore, in view of the above shortcomings, a device for preparing dimethylaminoethyl acrylate is urgently needed. Summary of the invention

[0005] The embodiment of the present invention provides a device for preparing dimethylaminoethyl acrylate, which can perform polymerization reaction and distillation purification.

[0006] The embodiment of the present invention provides a system for preparing dimethylaminoethanol acrylate, which comprises a reaction kettle and a distillation tower from bottom to top, wherein the distillation tower comprises a stripping unit and a rectification unit from bottom to top;

[0007] The reactor is used to contain the reaction liquid, and the reactor is provided with a heating device, and the heating device is used to heat the reactor to react the reactants in the reaction liquid and evaporate the reaction liquid;

[0008] The first mixed gas formed by evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence, the substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the gas is discharged from the rectification unit.

[0009] In a possible design, the reactor is connected to the top of the stripping unit through a pipeline, the reaction liquid in the reactor is pumped to the top of the stripping unit by a first diaphragm pump, and the reaction liquid at the top of the stripping unit passes through the stripping unit and flows into the reactor;

[0010] During the process of the reaction liquid flowing back from the top of the stripping unit to the reactor, the reaction liquid evaporates to form a second mixed gas. After the second mixed gas and the first mixed gas pass through the stripping unit and the rectification unit in sequence, methanol gas is obtained and discharged from the rectification unit.

[0011] In one possible design, a stirring wheel is provided inside the reactor, and the bottom of the reactor is connected to the liquid inlet of the stirring wheel through a pipeline. The first diaphragm pump pumps the reaction liquid in the reactor into the stirring wheel, and the reaction liquid in the stirring wheel flows back to the reactor. The stirring wheel is provided with a spiral guide plate, and the spiral guide plate includes a plurality of blades. The reaction liquid impacts the blades to drive the blades to rotate when passing through the spiral guide plate, and the blades rotate to stir the reaction liquid in the reactor.

[0012] In a possible design, the reactor is connected to the liquid storage tank through the first diaphragm pump, the liquid storage tank is connected to the second diaphragm pump, the second diaphragm pump is connected to the first spray head on the top of the stripping unit through a main pipeline, the second diaphragm pump is connected to the inhibitor tank through a branch pipeline, the main pipeline is provided with a venturi tube, the inhibitor tank is connected to the venturi tube, and the inhibitor tank contains inhibitor;

[0013] The reaction liquid in the reactor is pumped into the liquid storage tank by a first diaphragm pump, and the reaction liquid in the liquid storage tank is pumped into the first spray head by a second diaphragm pump. The first spray head sprays the reaction liquid to the distillation unit. The reaction liquid in the liquid storage tank is pumped into the inhibitor tank by the second diaphragm pump to dilute the inhibitor in the inhibitor tank. When the reaction liquid passes through the venturi tube, low pressure is formed so that the diluted inhibitor in the inhibitor dilution tube is sucked into the venturi tube. The diluted inhibitor in the venturi tube is mixed with the reaction liquid and output to the first spray head.

[0014] In one possible design, the main pipeline is connected in parallel with a secondary pipeline, and both the main pipeline and the secondary pipeline are provided with valves. The valve of the main pipeline is opened and the valve of the secondary pipeline is closed, and the diluted inhibitor in the inhibitor tank and the reaction liquid in the liquid storage tank are output to the first spray head through the main pipeline. The valve of the secondary pipeline is opened and the valve of the main pipeline is closed, and the reaction liquid in the liquid storage tank is output to the first spray head through the main pipeline.

[0015] In a possible design, a low-oxygen air distribution plate is provided at the bottom of the reactor, and the low-oxygen air distribution plate is connected to an air compressor outside the reactor through an air supply pipe. The low-oxygen air distribution plate is used to provide low-oxygen air to prevent polymerization reaction.

[0016] In a possible design, the hypoxic air distribution plate is provided with a plurality of upward air outlets, and the air outlets are provided with hole covers through three guide rails. When air is supplied, the hole covers rise along the guide rails, and when air supply is stopped, the hole covers descend along the guide rails to cover the air holes.

[0017] In a possible design, the heating device is wrapped around the outside of the reactor, and the heating device includes a protective layer, a core layer and a ceramic layer in sequence along the thickness direction. The protective layer is used to reduce heat loss, the core layer is used to provide heat, and the ceramic layer is in contact with the reactor to conduct heat to the reactor.

[0018] In a possible design, a second spray head is provided on the top of the distillation unit, and the second spray head is used to spray the insulation liquid to the distillation unit, and the insulation liquid includes liquefied methanol discharged from the distillation tower.

[0019] In a possible design, the diameter ratio of the reactor, the stripping unit and the rectification unit is 1:0.68-0.85:0.55-0.65.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] In this embodiment, the reactor is used to contain the reaction liquid, and the temperature required for the reaction can be provided to the reaction liquid through the heating device. In addition, the heating device is also used to provide thermal power for the evaporation of the reaction liquid. A distillation tower including a stripping unit and a rectification unit is arranged on the upper part of the reactor. The first mixed gas formed by the evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence. The substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the first mixed gas is discharged from the rectification unit. By combining the reactor with the distillation tower and placing the reactor at the bottom of the distillation tower, the excellent effect of simultaneous reaction and distillation can be achieved, saving time and plane space. In addition, the heating device can not only provide heat for the reaction, but also promote the evaporation of the reaction liquid to discharge the methanol out of the reactor, saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a schematic diagram of the structure of a system for preparing dimethyl ethyl acrylate provided in an embodiment of the present invention;

[0024] Figure 2 is a structural schematic diagram of a low oxygen air distribution plate provided by an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of a hole cover structure provided by an embodiment of the present invention;

[0026] Figure 4 It is a schematic diagram of a partial structure of a heating device provided by an embodiment of the present invention;

[0027] Figure 5 It is a schematic diagram of a local structure of a stirring cycle provided in a comparative example of the present invention;

[0028] Figure 6 It is a schematic diagram of a partial structure of another distillation unit cycle provided in a comparative example of the present invention.

[0029] In the figure:

[0030] 1- Air compressor;

[0031] 2-air supply pipe;

[0032] 3- Hypoxic air distribution plate;

[0033] 4- Protective layer;

[0034] 5-core layer;

[0035] 6- Porcelain interlayer;

[0036] 7-Manhole;

[0037] 8-liquid outlet pipe;

[0038] 9- first diaphragm pump;

[0039] 10-Drainage port;

[0040] 11-Liquid level gauge;

[0041] 12- stirring wheel;

[0042] 13-feeding port;

[0043] 14- first thermocouple interface;

[0044] 15-stripping section packing layer;

[0045] 16-first liquid phase distributor;

[0046] 17-liquid inlet pipe;

[0047] 18- first liquid return pipe;

[0048] 19-Liquid storage tank;

[0049] 20- distillation circulation pipe;

[0050] 21- second diaphragm pump;

[0051] 22- second liquid return pipe;

[0052] 23-inhibitor tank;

[0053] 24- Main pipeline;

[0054] 25- auxiliary pipeline;

[0055] 26-first sprinkler head;

[0056] 27-distillation section packing layer;

[0057] 28- second liquid phase distributor;

[0058] 29- second sprinkler head;

[0059] 30-tower top demister;

[0060] 31- second thermocouple interface;

[0061] 32-tower top gas phase discharge port;

[0062] 33-Safety accessory interface. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0064] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0066] like Figure 1As shown, an embodiment of the present invention provides a system for preparing dimethylaminoethanol acrylate, which comprises a reaction kettle and a distillation tower from bottom to top, and the distillation tower comprises a stripping unit and a rectification unit from bottom to top;

[0067] The reaction kettle is used to contain the reaction liquid. The reaction kettle is provided with a heating device, and the heating device is used to heat the reaction kettle to react the reactants in the reaction liquid and evaporate the reaction liquid.

[0068] The first mixed gas formed by evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence, the substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the gas is discharged from the rectification unit.

[0069] In this embodiment, the reactor is used to contain the reaction liquid, and the temperature required for the reaction can be provided to the reaction liquid through the heating device. In addition, the heating device is also used to provide thermal power for the evaporation of the reaction liquid. A distillation tower including a stripping unit and a rectification unit is arranged on the upper part of the reactor. The first mixed gas formed by the evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence. The substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the first mixed gas is discharged from the rectification unit. By combining the reactor with the distillation tower and placing the reactor at the bottom of the distillation tower, the excellent effect of simultaneous reaction and distillation can be achieved, saving time and plane space. In addition, the heating device can not only provide heat for the reaction, but also promote the evaporation of the reaction liquid to discharge the methanol out of the reactor, saving energy.

[0070] In this embodiment, a first liquid phase distributor 16 and a second liquid phase distributor 28 may be provided in the stripping unit and the rectification unit, respectively.

[0071] In this embodiment, the reactor is provided with a manhole 7, a feed port 13, a liquid level gauge 11 and a first thermocouple interface 14. The feed port 13 is used for feeding, the liquid level gauge 11 is used to obtain the liquid level height in the reactor, and the first thermocouple interface 14 is used to install a temperature and pressure detection device.

[0072] In this embodiment, the stripping unit and the rectification unit are filled with fillers, and the fillers are used to liquefy the substances with high boiling points in the mixed gas so that methanol can be discharged from the distillation tower in the gas phase. According to the ideal system gas-liquid phase equilibrium equation, the coordinate calculation formula of the intersection of the rectification section operating line and the stripping section operating line, the operating line equation and the q line equation, the required theoretical number of plates is calculated, and then the filler model, height and porosity are calculated and determined according to the relationship between the number of plates and the filler height and bulk density. The porosity of the filler layer decreases from bottom to top, which is convenient for uniform distribution of gas flow; the filler material is based on the material that is not easy to be blocked, and ball rings and saddle rings are preferred.

[0073] like Figure 1 and Figure 6As shown, in some embodiments of the present invention, the reactor is connected to the top of the stripping unit through a pipeline, and the reaction liquid in the reactor is pumped to the top of the stripping unit by the first diaphragm pump 9, and the reaction liquid at the top of the stripping unit passes through the stripping unit and flows into the reactor;

[0074] During the process of the reaction liquid flowing back from the top of the distillation unit to the reactor, the reaction liquid evaporates to form a second mixed gas. The second mixed gas and the first mixed gas pass through the distillation unit and the rectification unit in sequence to obtain methanol gas which is discharged from the rectification unit.

[0075] In this embodiment, the reactor is connected to the top of the stripping unit by a pipeline, and the pipeline is provided with a first diaphragm pump 9. The first diaphragm pump 9 is used to pump the reaction liquid in the reactor to the top of the stripping unit. The reaction liquid at the top of the stripping unit flows into the reactor through the stripping unit to form a cycle of the reaction liquid. During the cycle of the reaction liquid, the reaction liquid continuously flows into the reactor from the top of the stripping unit. During the process of the reaction liquid passing through the stripping unit, it continuously evaporates to form a second mixed gas. The second mixed gas passes through the stripping unit and the rectification unit in sequence upward. The substance with a high boiling point liquefies and flows downward into the reactor during the upward process. The methanol with a low boiling point passes through the rectification unit upward and is discharged from the distillation tower. The continuous circulation increases the efficiency of distillation. During the downward flow of the reaction liquid, the liquefaction of the low boiling point substance in the mixed gas is promoted. At the same time, the high boiling point substance in the reaction liquid is more likely to vaporize and enter and move upward with the mixed gas, and finally the methanol in the reactor is quickly discharged, thereby improving the quality of dimethylaminoethyl acrylate in the reactor.

[0076] like Figure 5 As shown, in some embodiments of the present invention, a stirring wheel 12 is provided inside the reactor, and the bottom of the reactor is connected to the liquid inlet of the stirring wheel 12 through a pipeline. The first diaphragm pump 9 pumps the reaction liquid in the reactor into the stirring wheel 12, and the reaction liquid in the stirring wheel 12 flows back to the reactor. The stirring wheel 12 is provided with a spiral guide plate, and the spiral guide plate includes a plurality of blades. When the reaction liquid passes through the spiral guide plate, it impacts the blades to drive the blades to rotate, and the blades rotate to stir the reaction liquid in the reactor.

[0077] In this embodiment, the reaction liquid in the reactor is pumped to the stirring wheel 12 for output through the first diaphragm pump 9. A spiral guide plate including a plurality of blades is provided in the stirring wheel 12. During the process of the reaction liquid being output from the stirring wheel 12, the blades are continuously impacted to cause the blades to rotate. The rotating blades continuously stir the reaction liquid in the reactor, thereby accelerating the rate of evaporation and reaction.

[0078] like Figure 1 and Figure 6As shown, in some embodiments of the present invention, the reactor is connected to the liquid storage tank 19 through the first diaphragm pump 9, the liquid storage tank 19 is connected to the second diaphragm pump 21, the second diaphragm pump 21 is connected to the first spray head 26 at the top of the stripping unit through the main pipeline 24, the second diaphragm pump 21 is connected to the inhibitor tank 23 through a branch pipeline, the main pipeline 24 is provided with a venturi tube, the inhibitor tank 23 is connected to the venturi tube, and the inhibitor tank 23 is filled with inhibitor;

[0079] The reaction liquid in the reactor is pumped into the liquid storage tank 19 by the first diaphragm pump 9, and the reaction liquid in the liquid storage tank 19 is pumped into the first spray head 26 by the second diaphragm pump 21. The first spray head 26 sprays the reaction liquid to the distillation unit. The reaction liquid in the liquid storage tank 19 is pumped into the inhibitor tank 23 by the second diaphragm pump 21 to dilute the inhibitor in the inhibitor tank 23. When the reaction liquid passes through the venturi tube, low pressure is formed, so that the diluted inhibitor in the inhibitor dilution tube is sucked into the venturi tube, and the diluted inhibitor in the venturi tube is mixed with the reaction liquid and output to the first spray head 26.

[0080] In this embodiment, the reaction liquid in the reactor is pumped into the liquid storage tank 19 by the first diaphragm pump 9, so that the liquid storage tank 19 is filled with the reaction liquid, and the reaction liquid in the liquid storage tank 19 is pumped into the first spray head 26 through the main pipeline 24 by the second diaphragm pump 21, and the reaction liquid is sprayed to the distillation unit through the first spray head 26 to accelerate the evaporation and separation of the reaction liquid. In order to prevent the reaction liquid from polymerizing during the spraying process, a polymerization inhibitor needs to be added before the reaction liquid enters the first spray head 26, but excessive polymerization inhibitor will affect the quality of the product. Therefore, a polymerization inhibitor tank 23 containing polymerization inhibitor is provided, and the polymerization inhibitor tank 23 is connected to a quantitative addition system, and the quantitative addition system is used to add polymerization inhibitor to the polymerization inhibitor tank 23. At the same time, the polymerization inhibitor tank 23 is connected to the liquid storage tank 19, and the reaction liquid in the liquid storage tank 19 is pumped into the polymerization inhibitor tank 23 through the second diaphragm pump 21 to obtain the diluted polymerization inhibitor; the polymerization inhibitor tank 23 is also connected to the venturi tube in the main pipeline 24 through a branch pipeline. When the reaction liquid in the main pipeline 24 passes through the venturi tube, a low pressure is formed at the venturi tube. Under the action of the low pressure, the diluted polymerization inhibitor in the polymerization inhibitor tank 23 is sucked into the venturi tube through the branch pipeline, and the diluted polymerization inhibitor and the reaction liquid in the main pipeline 24 enter the first spray head 26 together and then sprayed to the distillation unit. After the diluted polymerization inhibitor is sprayed to the distillation unit with the reaction liquid, a part of it flows downward with the liquid phase to prevent the liquid phase substance from undergoing polymerization reaction, and a part of it vaporizes and flows upward with the gas phase to prevent the gas phase substance from undergoing polymerization reaction.

[0081] like Figure 6As shown, in some embodiments of the present invention, the main pipeline 24 is connected in parallel with the secondary pipeline 25, and both the main pipeline 24 and the secondary pipeline 25 are provided with valves. The valve of the main pipeline 24 is opened and the valve of the secondary pipeline 25 is closed, and the diluted inhibitor in the inhibitor tank 23 and the reaction liquid in the liquid storage tank 19 are output to the first spray head 26 through the main pipeline 24. The valve of the secondary pipeline 25 is opened and the valve of the main pipeline 24 is closed, and the reaction liquid in the liquid storage tank 19 is output to the first spray head 26 through the main pipeline 24.

[0082] In this embodiment, a small amount of polymerization inhibitor is added to the reactor to prevent the reactants in the reaction liquid from undergoing polymerization reaction when the temperature is increased. After the temperature of the reactants in the reactor reaches a preset temperature, the secondary pipeline 25 is opened to allow the first spray head 26 to spray the reaction liquid. As the polymerization inhibitor in the reactor is continuously consumed, the secondary pipeline 25 is closed, and the main pipeline 24 is opened to allow the first spray head 26 to output the diluted polymerization inhibitor and the reaction liquid. In this way, a small amount of polymerization inhibitor is always maintained in the reaction system, thereby preventing polymerization reaction from occurring in the reaction system. At the same time, the product quality will not be affected by excessive polymerization inhibitor.

[0083] In this embodiment, the liquid storage tank 19 is provided with a first liquid return pipe 18, and the inhibitor tank 23 is provided with a second liquid return pipe 22. The first liquid return pipe 18 and the second liquid return pipe 22 are used to discharge the reaction liquid during shutdown or maintenance. During normal operation, the first liquid return pipe 18 and the second liquid return pipe 22 are closed.

[0084] It should be noted that the reactor is connected to the first diaphragm pump 9 through the liquid outlet pipe 8, and the first diaphragm pump 9 is connected to the liquid storage tank 19 through the liquid inlet pipe 17. The first diaphragm pump 9 is connected to the liquid discharge port 10. When the liquid in the reactor needs to be drained, the liquid discharge port 10 is opened and the first diaphragm pump 9 is used to discharge the liquid in the reactor through the liquid discharge port 10.

[0085] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments of the present invention, a low oxygen air distribution plate 3 is provided at the bottom of the reactor, and the low oxygen air distribution plate 3 is connected to the air compressor 1 outside the reactor through the air supply pipe 2. The low oxygen air distribution plate 3 is used to provide low oxygen air to prevent polymerization reaction.

[0086] In this embodiment, a low oxygen air distribution plate 3 is arranged at the bottom of the reactor. The low oxygen air distribution plate 3 can output low oxygen air upwards. The low oxygen air can both hinder the polymerization reaction and increase the aerodynamic force.

[0087] It is understandable that the low oxygen air distribution plate 3 can also be connected to a compressor filled with nitrogen to output nitrogen to the reactor.

[0088] In some embodiments of the present invention, the hypoxic air distribution plate 3 is provided with a plurality of upward air outlets, and the air outlets are provided with hole covers through three guide rails. When air is supplied, the hole covers rise along the guide rails, and when the air supply is stopped, the hole covers descend along the guide rails to cover the air holes.

[0089] In this embodiment, the hypoxic air distribution plate 3 is provided with a plurality of upward air outlet holes, and the air outlet holes are provided with hole covers through guide rails. When the air outlet holes output gas, the gas drives the hole covers to slide upward along the guide rails, and the gas is output from between the hole openings and the hole covers. When the gas supply is stopped, the hole covers slide down along the guide rails to close the hole covers to prevent the reaction liquid from entering the air outlet holes along the hole openings.

[0090] It is understandable that a rubber ring can be provided at the bottom of the hole cover to further increase the sealing performance when the hole cover is closed. A spring can be provided on the slide rail to increase the speed of closing the hole cover, and the spring force needs to be less than the pneumatic force of the outlet.

[0091] In this embodiment, the air outlet holes of the hypoxic air distribution plate 3 may be filled with porous materials, such as air bubble stones. The air outlet holes are detachable for easy maintenance.

[0092] like Figure 4 As shown, in some embodiments of the present invention, the heating device is coated on the outside of the reactor, and the heating device includes a protective layer 4, a core layer 5 and a ceramic layer 6 in sequence along the thickness direction. The protective layer 4 is used to reduce heat loss, the core layer 5 is used to provide heat, and the ceramic layer 6 is in contact with the reactor and is used to conduct heat to the reactor.

[0093] In this embodiment, the protective layer 4 is made of bakelite and ABS engineering plastics, preferably heat-resistant and high-hardness bakelite material, lined with a high-temperature reflective coating to locally change the direction of heat radiation and reduce heat loss. The core layer 5 includes electromagnetic heating copper wire, heating ceramic body and filler, and the filler plays an insulating and heat-preserving role. The bottom of the reactor is heated by electromagnetic heating copper wire, and the side wall of the reactor is heated by heating ceramic body. The ceramic layer 6 is processed by split assembly or integrated molding, and the contact surface with the reactor is coated with thermal conductive silicone to ensure close bonding with the outer wall of the reactor, ensure the heat conduction effect, and prevent corrosion of the outer wall of the reactor.

[0094] It should be noted that the outer wall of the ceramic layer 6 is in contact with the heating copper wire or the heating ceramic body of the core layer 5 , and a groove matching the heating copper wire or the heating ceramic body needs to be reserved in the ceramic layer 6 .

[0095] In some embodiments of the present invention, a second spray head 29 is disposed on the top of the distillation unit, and the second spray head 29 is used to spray the insulation liquid to the distillation unit, and the insulation liquid includes liquefied methanol discharged from the distillation tower.

[0096] In this embodiment, the methanol gas is condensed into liquid after being discharged from the distillation tower, and part of the liquid can be sprayed to the distillation unit through the second spray head 29 to keep the temperature of the top of the distillation unit.

[0097] It should be noted that whether to spray the condensate of the by-product through the second spray head 29 can be determined according to the value of the tower top temperature and pressure monitoring interface.

[0098] In some embodiments of the present invention, the diameter ratio of the reactor, the stripping unit and the rectification unit is 1:0.68-0.85:0.55-0.65.

[0099] In this embodiment, the diameter ratio of the reactor, the stripping unit and the rectification unit is preferably 1:0.73:0.56. The reactor and the distillation tower adopt a variable diameter design, which is conducive to increasing the evaporation area of ​​the stripping section and increasing the gas phase evaporation amount. At the same time, it also correspondingly extends the path of the gas phase distillation section and the area of ​​gas phase liquefaction, which is conducive to the liquefaction and reflux of high-boiling point substances, improves the product yield while improving the purity of distillation separation, and shortens the reaction time. The tower body design that tapers from bottom to top can significantly enhance the aerodynamic force of the gas phase.

[0100] It should be noted that the distillation tower may be provided with a second thermocouple interface 31 and a safety accessory interface 33. The system provided by the present invention is provided with an online detection device for temperature, pressure, pump current, and pump voltage, which is connected to the PLC distributed control system in the main control room, and sends control signals to automatic flow meters, electromagnetic control valves and other devices according to the transmitted temperature and pressure data, controls the reaction liquid circulation flow, gas supply, inhibitor mixed addition amount and tower top temperature, maintains the normal reaction of the entire system, and the distillation product index is qualified.

[0101] Example:

[0102] Reactive distillation methanol separation section:

[0103] Start the air compressor 1, and supply air to the reactor through the air delivery pipe 2 and the hypoxic air distribution plate 3; open the feed port 13, add dimethylaminoethanol and methyl acrylate to the reactor, and the methyl acrylate should be excessive. After reaching the heating start liquid level, the liquid level meter 11 transmits the liquid level signal to the control center, starts the heating device for heating, and continues to add materials until the specified reaction liquid level is reached; when heated to 80°C, add butyl tin oxide catalyst through the catalyst feeding system through the feeding port, start the first diaphragm pump 9, the reaction liquid enters the liquid outlet pipe 8, and then enters the stirring wheel 12. The reaction liquid pushes the stirring wheel 12 to strengthen the stirring of the reaction liquid, and starts the heating ceramic body in the core layer 5 for heating. The temperature rises to the reaction temperature of 100°C within the specified time. The electromagnetic heating part is the main part, and the heating of the heating ceramic body is the secondary part. The reaction temperature is maintained. The electromagnetic heating is controlled by the online temperature monitoring device connected to the first thermocouple interface 14. The advance amount can be set by the control system to keep the temperature of the reaction liquid stable. After keeping the reaction for 1.5 to 2 hours, slowly add the azeotropic agent, and the azeotropic agent is preferably n-hexane.

[0104] While adding the azeotropic agent, the liquid inlet pipe 17 is opened to inject the reaction liquid into the liquid storage tank 19. After reaching the set liquid level, a signal is sent to start the second diaphragm pump 21. In the first half of the reaction time, the auxiliary pipeline 25 is kept open and the main pipeline 24 is closed, and the reaction liquid is sprayed down through the distillation circulation pipe 20, the second diaphragm pump 21, the auxiliary pipeline 25, and the first spray head 26; in the second half of the reaction time, the auxiliary pipeline 25 is closed and the main pipeline 24 is opened, and the inhibitor is added to the inhibitor tank 23 through the quantitative addition system, and the diluent enters the inhibitor tank 23 through the branch pipeline of the second diaphragm pump 21. The diluted inhibitor is mixed through the main pipeline 24 and enters the first spray head 26, mixed with the reaction liquid, sprayed to the first liquid phase distributor 16, and returned to the reactor through the stripping section packing layer 15.

[0105] After the liquid phase circulates normally, the gas phase passes through the stripping section packing layer 15, the rectifying section packing layer 27, the second liquid phase distributor 28, the second spray head 29, and the tower top demister 30 and rises to the tower top gas phase discharge port 32. The tower top temperature rises to 45°C to 55°C, preferably 50.5°C. The tower top gas phase discharge port 32 is opened, and the gas phase enters the condenser. The reflux pump is started after the condensate tank reaches the reflux pump start level to maintain the tower top temperature, and the entrainer and methanol mixed liquid are separated. After the mixed liquid is allowed to stand and separate, the entrainer is cut out for recycling, and the methanol aqueous solution is further distilled and purified, and enters the finished product tank after reaching the takeaway standard.

[0106] The reaction process can last for 6 to 8 hours. During the reaction, the positive pressure in the tower should be maintained and the condensation cycle should be increased. After the sampling is qualified, the reaction distillation separation of methanol section ends and enters the product distillation section.

[0107] Product distillation section:

[0108] The product distillation period lasts for 5 to 8 hours, preferably 6.5 hours. Keep the solenoid valve of the secondary pipeline 25 closed. A part of the circulating liquid of the reactor enters the liquid storage tank 19 through the liquid inlet pipe 17. Under the action of the second diaphragm pump 21, the circulating liquid is sprayed down through the distillation circulation pipe 20 and the main pipeline 24 through the first spray head 26. The tower top temperature is controlled at 60°C to 80°C, preferably 65°C.

[0109] When the product is distilled, compared with the reaction distillation section, it is necessary to turn on the vacuum pump on the top of the tower to maintain the negative pressure in the tower and perform reduced pressure distillation on the product, which is more convenient for improving the purity of the product.

[0110] Implementation effect: Compared with ordinary distillation towers, the dosage of inhibitor is reduced by more than 22%, the product yield is increased by more than 5%, and the loss rate is reduced by about 0.8%.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preparing dimethylaminoethanol acrylate, characterized in that: The device comprises a reaction kettle and a distillation tower from bottom to top, wherein the distillation tower comprises a stripping unit and a rectifying unit from bottom to top; The reactor is used to contain the reaction liquid, and the reactor is provided with a heating device, and the heating device is used to heat the reactor to react the reactants in the reaction liquid and evaporate the reaction liquid; The first mixed gas formed by evaporation of the reaction liquid in the reactor passes through the stripping unit and the rectification unit in sequence, the substances with high boiling points in the first mixed gas are liquefied and flow back to the reactor, and the methanol with low boiling points in the gas is discharged from the rectification unit; The reactor is connected to the top of the stripping unit via a pipeline, and the reaction liquid in the reactor is pumped to the top of the stripping unit via a first diaphragm pump (9), and the reaction liquid at the top of the stripping unit passes through the stripping unit and flows into the reactor; During the process of the reaction liquid flowing back from the top of the stripping unit to the reactor, the reaction liquid evaporates to form a second mixed gas, and the second mixed gas and the first mixed gas pass through the stripping unit and the rectification unit in sequence upward to obtain methanol gas discharged from the rectification unit; The reaction kettle is connected to a liquid storage tank (19) via the first diaphragm pump (9), the liquid storage tank (19) is connected to a second diaphragm pump (21), the second diaphragm pump (21) is connected to a first spray head (26) at the top of the stripping unit via a main pipeline (24), the second diaphragm pump (21) is connected to a polymerization inhibitor tank (23) via a branch pipeline, the main pipeline (24) is provided with a venturi tube, the polymerization inhibitor tank (23) is connected to the venturi tube, and the polymerization inhibitor tank (23) contains a polymerization inhibitor; The reaction liquid in the reactor is pumped into the liquid storage tank (19) by using the first diaphragm pump (9), and the reaction liquid in the liquid storage tank (19) is pumped into the first spray head (26) by using the second diaphragm pump (21). The first spray head (26) sprays the reaction liquid to the distillation unit. The reaction liquid in the liquid storage tank (19) is pumped into the inhibitor tank (23) by using the second diaphragm pump (21) to dilute the inhibitor in the inhibitor tank (23). When the reaction liquid passes through the venturi tube, a low pressure is formed, so that the diluted inhibitor in the inhibitor tank (23) is sucked into the venturi tube. The diluted inhibitor in the venturi tube is mixed with the reaction liquid and output to the first spray head (26).

2. The device according to claim 1, characterized in that A stirring wheel (12) is arranged inside the reactor. The bottom of the reactor is connected to the liquid inlet of the stirring wheel (12) through a pipeline. The first diaphragm pump (9) pumps the reaction liquid in the reactor into the stirring wheel (12). The reaction liquid in the stirring wheel (12) flows back to the reactor. The stirring wheel (12) is provided with a spiral guide plate. The spiral guide plate includes a plurality of blades. When the reaction liquid passes through the spiral guide plate, it impacts the blades to drive the blades to rotate. The blades rotate to stir the reaction liquid in the reactor.

3. The device according to claim 1, characterized in that The main pipeline (24) is connected in parallel with a secondary pipeline (25). Both the main pipeline (24) and the secondary pipeline (25) are provided with valves. When the valve of the main pipeline (24) is opened and the valve of the secondary pipeline (25) is closed, the diluted polymerization inhibitor in the polymerization inhibitor tank (23) and the reaction liquid in the liquid storage tank (19) are output to the first spray head (26) through the main pipeline (24). When the valve of the secondary pipeline (25) is opened and the valve of the main pipeline (24) is closed, the reaction liquid in the liquid storage tank (19) is output to the first spray head (26) through the main pipeline (24).

4. The device according to claim 1, characterized in that A low-oxygen air distribution plate (3) is arranged at the bottom of the reactor. The low-oxygen air distribution plate (3) is connected to an air compressor (1) outside the reactor via an air supply pipe (2). The low-oxygen air distribution plate (3) is used to provide low-oxygen air to prevent polymerization reaction.

5. The device according to claim 4, characterized in that The hypoxic air distribution plate (3) is provided with a plurality of upward air outlet holes, and the air outlet holes are provided with hole covers via three guide rails. When air is supplied, the hole covers rise along the guide rails, and when air supply is stopped, the hole covers descend along the guide rails to cover the air holes.

6. The device according to claim 1, characterized in that The heating device is coated on the outside of the reaction kettle, and the heating device comprises a protective layer (4), a core layer (5) and a ceramic layer (6) in sequence along the thickness direction; the protective layer (4) is used to reduce heat loss, the core layer (5) is used to provide heat, and the ceramic layer (6) is in contact with the reaction kettle and is used to conduct heat to the reaction kettle.

7. The device according to claim 1, characterized in that A second spray head (29) is arranged on the top of the distillation unit, and the second spray head (29) is used to spray a heat preservation liquid onto the distillation unit, wherein the heat preservation liquid includes liquefied methanol discharged from the distillation tower.

8. The device according to claim 1, characterized in that The diameter ratio of the reactor, the stripping unit and the rectification unit is 1:0.68~0.85:0.55~0.65.

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