A continuous reactive distillation equipment for synthesizing diacetone alcohol

Abstract

The present invention discloses a continuous reactive distillation equipment for synthesizing diacetone alcohol, which comprises a distillation column, an opening and closing mechanism, a condensation mechanism and a rotating mechanism. By setting the opening and closing mechanism, without affecting the operating pressure inside the distillation column, the gas-phase flow is adjusted to extend the residence time of propanol in the reaction section, thereby improving the conversion rate to ensure that the propanol raw material reacts fully to increase the output of the equipment; by setting the condensation mechanism, the discharge path of the by-product water is increased, and the reflux of water is further reduced to reduce its interference with the reaction process, while effectively improving the product purity of diacetone alcohol; by setting the rotating mechanism, coaxial reverse rotation between the reaction section and the reboiler is achieved. While ensuring the uniform distribution of the liquid phase during the reflux of propanol, the liquid phase mixing is promoted by stirring to further improve the separation efficiency of diacetone alcohol and water, thereby reducing its residence time in the high-temperature region to reduce the occurrence of side reactions.

Description

Technical Field

[0001] The present invention relates to the technical field of continuous catalytic distillation, and particularly to a continuous reaction distillation apparatus for synthesizing diacetone alcohol. Background Art

[0002] Diacetone alcohol is a colorless and transparent liquid organic compound, usually prepared by the aldol condensation reaction of acetone; since water is produced as a by-product while the reaction generates diacetone alcohol, in order to efficiently separate the products and improve the reaction efficiency, a continuous reaction distillation apparatus is adopted and the reaction is combined with distillation to achieve the efficient and continuous production of diacetone alcohol, while reducing energy consumption and operating costs.

[0003] After retrieval, a Chinese patent with the publication number CN118179072A includes a catalytic distillation column, a condenser and an internal reboiler. The catalytic distillation column includes two parts, a reaction section and a stripping section. The feed inlet of the catalytic distillation column is located between the reaction section and the stripping section. An external condenser is provided at the top of the catalytic distillation column. The inlet end of the condenser is connected to the top outlet of the catalytic distillation column, and the outlet end of the condenser is connected to the side inlet at the top of the catalytic distillation column. The internal reboiler is provided at the bottom of the catalytic distillation column, and a bottom product withdrawal port is provided at the bottom of the catalytic distillation column. This solution not only significantly improves the reaction conversion rate (>99.9%), but also the reaction selectivity reaches 100%, avoiding the generation of by-products and the decomposition of diacetone alcohol, reducing the reaction energy consumption. In addition, the product does not require subsequent separation and the catalyst does not require separation and recovery.

[0004] However, for the above solution, during the process of condensing and refluxing the vaporized light component propanol by setting a condenser at the top of the tower, the extraction of water is not considered, resulting in all the by-product water flowing back to the tower, which may interfere with the reaction process, leading to incomplete reaction of the propanol raw material and thus reducing the yield of diacetone alcohol in the solution; on the other hand, during the process of fractionating the mixture of diacetone alcohol and water by the internal reboiler in the above solution, due to the incomplete vaporization of water and the situation of condensation and reflux after the water vapor rises, it is difficult to effectively separate diacetone alcohol and water, and thus the diacetone alcohol in the solution is difficult to reach the expected product purity. Summary of the Invention

[0005] The purpose of the present invention is to provide a continuous reaction distillation apparatus for synthesizing diacetone alcohol, which has the advantages of cyclic reaction and segmented separation, and solves the problems in the background art.

[0006] To achieve the above object, the present invention provides the following technical solution: a continuous reaction and distillation equipment for synthesizing diacetone alcohol, comprising a distillation tower, an opening and closing mechanism, a condensing mechanism and a rotating mechanism, one side of the distillation tower is connected with a feed pipe, and the interior of the distillation tower is sequentially provided with a reaction section three, a reaction section two, a reaction section one, a stripping section and a reboiler from top to bottom, the reaction section one, the reaction section two and the reaction section three are sequentially fixedly connected and are connected to the inner wall of the distillation tower in a limited rotation manner, the feed pipe is unidirectionally connected to the reaction section one, the stripping section and the reboiler are fixedly connected and are fixedly connected to the inner wall of the distillation tower, the bottom end of the distillation tower is penetrated by a withdrawal pipe and the reboiler is unidirectionally connected to the withdrawal pipe;

[0007] The opening and closing mechanism is arranged at the top of the distillation tower, and the opening and closing mechanism includes a flow guide fixedly connected to the outer periphery of the upper surface of the reaction section three and a pressure sensor fixedly connected to the center of the upper surface of the reaction section three;

[0008] The condensing mechanism comprises a condensing group arranged on one side of the outside of the distillation tower, wherein the condensing group is provided with a condenser 1 and a condenser 2, and the condenser 1 is unidirectionally connected to the condenser 2, a gas phase pipe is unidirectionally connected from the top of the distillation tower to the condenser 1, and a reflux pipe that runs through the side of the distillation tower is unidirectionally connected from the condenser 2 to the reaction section 1;

[0009] The rotating mechanism realizes uniform distribution of the liquid phase in the reaction section and sufficient mixing of the liquid phase in the bottom of the tower, and comprises a fixed ring penetrating and fixedly connected to the center of the stripping section;

[0010] The absolute operating pressure of the distillation tower is 20-25 kPa, the tower top temperature is 60-65°C, the tower bottom temperature is 90-100°C, and the distillation tower space velocity is: ;

[0011] The reaction section one, the reaction section two and the reaction section three are combined into a reaction section, the temperature of the reaction section is 70-80°C, the reaction section is filled with a catalytic filler, and the catalyst in the catalytic filler is a hydroxide-type macroporous alkaline resin, the reaction section one is filled with 828 resin, and the reaction sections two and three are filled with D296 resin.

[0012] Preferably, the opening and closing mechanism further comprises a sealing plate 1 arranged at the top of the flow guide cover and the sealing plate 1 is fixedly connected to the inner wall of the distillation tower, the upper surface limit of the sealing plate 1 is penetrated by four positioning shafts which are arranged around at equal intervals, the tops of the four positioning shafts are penetrated by the same sealing plate 2 and the sealing plate 2 is fixedly connected to the inner wall of the distillation tower, the middle sections of the four positioning shafts are fixedly connected to opening and closing arms and the four opening and closing arms are spliced ​​with each other, and the outer contour of the opening and closing arm is meshingly connected to a gear ring located between the sealing plate 1 and the sealing plate 2;

[0013] On the outer contour of the ring gear, a driving wheel located outside the rectification column is meshed and drivingly connected. A protective frame is arranged on the outer contour of the driving wheel, and the protective frame is fixedly connected to the outer wall of the rectification column. A regulating shaft is fixedly connected to the center of the driving wheel, and the regulating shaft penetrates through the protective frame and extends upward.

[0014] Preferably, gas-phase holes adapted to the top contour of the flow guide cover are provided at the centers of the first sealing plate and the second sealing plate. The regulating shaft is driven by an external motor, and the external motor is electrically connected to the pressure sensor through a signal.

[0015] Preferably, the temperature of the first condenser is set to 50 - 55 °C, and the temperature of the second condenser is set to 0 - 10 °C.

[0016] Preferably, the rotating mechanism further includes a cross shaft fixedly connected to the inner contour of the fixed ring. The top of the cross shaft penetrates and is rotatably connected to a first bevel gear, and the first bevel gear is fixedly connected to the lower surface of the first reaction section. On both sides of the cross shaft, second bevel gears with opposite rotation directions penetrate and are rotatably connected. The bottom of the cross shaft penetrates and is rotatably connected to a third bevel gear. A differential is fixedly connected to the bottom of the third bevel gear, and the differential is rotatably connected to the center of the stripping section. A rotating shaft is fixedly connected to the bottom of the differential, and blades are arranged on the outer contour of the rotating shaft.

[0017] Preferably, both of the second bevel gears are meshed and drivingly connected to the first bevel gear and the third bevel gear. The rotating shaft and the blades are located inside the reboiler. The first bevel gear is driven by a built-in low-speed motor, the rotation speed of the first bevel gear is 1 - 5 rpm, the magnification ratio of the differential is one to fifty, and the rotation speed of the rotating shaft is 50 - 250 rpm.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. By setting the opening and closing mechanism, without affecting the operating pressure inside the rectification column, the gas-phase flow is adjusted to extend the residence time of propanol in the reaction section, thereby improving the conversion rate to ensure that the propanol raw material reacts sufficiently to increase the output of the device;

[0020] 2. By setting the condensation mechanism, the discharge path of the by-product water is increased, further reducing the water reflux, thereby reducing its interference with the reaction process, and at the same time effectively improving the product purity of diacetone alcohol;

[0021] 3. By setting the rotating mechanism, coaxial reverse rotation between the reaction section and the reboiler is achieved. While ensuring uniform distribution of the liquid phase during propanol reflux, the liquid phase mixing is promoted by stirring to further improve the separation efficiency of diacetone alcohol and water, thereby reducing its residence time in the high-temperature area to reduce the occurrence of side reactions. Description of the Drawings

[0022] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0023] Figure 2 This is a cross-sectional view of the main structure of the present invention;

[0024] Figure 3 This is a cross-sectional view of the rectifying column structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the position of the opening and closing mechanism of the present invention;

[0026] Figure 5 This is an exploded view of the opening and closing mechanism of the present invention;

[0027] Figure 6 This is a schematic diagram of the condensation mechanism of the present invention;

[0028] Figure 7 This is a schematic diagram of the position of the rotating mechanism of the present invention;

[0029] Figure 8 This is a partial schematic diagram of the rotating mechanism of the present invention;

[0030] Figure 9 This is a partial cross-sectional view of the rotating mechanism of the present invention.

[0031] In the figure: 1, rectifying column; 11, feed pipe; 12, reaction section one; 13, reaction section two; 14, reaction section three; 15, stripping section; 16, reboiler; 17, draw-off pipe; 2, guide hood; 21, pressure sensor; 22, sealing plate one; 23, sealing plate two; 24, gear ring; 25, positioning shaft; 26, opening and closing arm; 27, driving wheel; 28, protection frame; 29, adjusting shaft; 3, condensation group; 31, gas phase pipe; 32, condenser one; 33, condenser two; 34, reflux pipe; 35, discharge pipe; 4, fixed ring; 41, cross shaft; 42, bevel gear one; 43, bevel gear two; 44, bevel gear three; 45, differential; 46, rotating shaft; 47, paddle. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Example 1, please refer to Figures 1 to 9The present invention provides a technical solution: a continuous reaction and distillation equipment for synthesizing diacetone alcohol, comprising a distillation tower 1, an opening and closing mechanism, a condensing mechanism and a rotating mechanism, characterized in that: a feed pipe 11 is connected to one side of the distillation tower 1, and a reaction section three 14, a reaction section two 13, a reaction section one 12, a stripping section 15 and a reboiler 16 are sequentially arranged inside the distillation tower 1 from top to bottom, the reaction section one 12, the reaction section two 13 and the reaction section three 14 are sequentially fixedly connected and are connected to the inner wall of the distillation tower 1 in a limited rotation manner, the feed pipe 11 is unidirectionally connected to the reaction section one 12, the stripping section 15 and the reboiler 16 are fixedly connected and are fixedly connected to the inner wall of the distillation tower 1, and a withdrawal pipe 17 is passed through the bottom end of the distillation tower 1 and the reboiler 16 is unidirectionally connected to the withdrawal pipe 17;

[0034] The opening and closing mechanism is arranged at the top of the distillation tower 1, and the opening and closing mechanism includes a flow guide 2 fixedly connected to the outer periphery of the upper surface of the reaction section three 14 and a pressure sensor 21 fixedly connected to the center of the upper surface of the reaction section three 14;

[0035] The rotating mechanism realizes uniform distribution of the liquid phase in the reaction section and sufficient mixing of the liquid phase in the bottom of the tower, and comprises a fixed ring 4 penetrating and fixedly connected to the center of the stripping section 15;

[0036] The absolute operating pressure of the distillation tower 1 is 20-25 kPa, the tower top temperature is 60-65°C, the tower bottom temperature is 90-100°C, and the space velocity of the distillation tower 1 is: ;

[0037] The reaction section one 12, the reaction section two 13 and the reaction section three 14 are combined into a reaction section, the temperature of the reaction section is 70-80°C, the reaction section is filled with catalytic fillers and the catalyst in the catalytic fillers is a hydroxide-type macroporous alkaline resin, the reaction section one 12 is filled with 828 resin, and the reaction section two 13 and the reaction section three 14 are filled with D296 resin.

[0038] In this scheme, propanol enters the middle section of the distillation tower 1 through the feed pipe 11, and after entering the reaction section 12, it is vaporized under the heating action of the reboiler 16 and starts to react under the action of the catalyst, wherein the high catalytic activity of 828 resin is utilized in the reaction section 12 to quickly initiate the condensation reaction of propanol, the high selectivity of D296 resin is utilized in the reaction section 2 13 to promote the further conversion of the intermediate product into diacetone alcohol, and the deep reaction is further completed in the reaction section 3 14 to ensure that the reactants are fully converted.

[0039] It should be noted that the total height of the reaction section is 4 - 6 meters. Among them, the height of reaction section one 12 is 1.5 - 2.5 meters, accounting for 30% - 40% of the total height of the reaction section; the height of reaction section two 13 is 1.5 - 2.5 meters, accounting for 30% - 40% of the total height of the reaction section; the height of reaction section three 14 is 1 - 2 meters, accounting for 20% - 30% of the total height of the reaction section.

[0040] During this process, the gas pressure near the top of the distillation column 1 is monitored in real time through the opening and closing mechanism, and the connection state between the distillation column 1 and the condensation mechanism is controlled by setting a pressure threshold. When the gas pressure at the top of the distillation column 1 exceeds the threshold, the opening and closing mechanism automatically opens to release the excess gas phase and reduce the pressure inside the column; when the gas pressure at the top of the distillation column 1 does not reach the threshold, the opening and closing mechanism remains closed to increase the gas phase residence time and improve the reaction efficiency; that is, the opening and closing mechanism adjusts the gas phase flow to extend the residence time of propanol in the reaction section, ensuring its full reaction to improve the conversion rate of the scheme.

[0041] It should be noted that since the absolute operating pressure of the distillation column 1 is 20 - 25 kPa, the top temperature is 60 - 65 °C, and the temperature of the reaction section is 70 - 80 °C. Under the low-pressure environment of 20 - 25 kPa, the boiling point of water is 60 - 65 °C, the boiling point of propanol is 40 - 45 °C, and the boiling point of diacetone alcohol is 100 - 105 °C. That is, the gas phase composition at the top of the column is a mixture of water vapor and vaporized propanol, and diacetone alcohol is in a liquid state and flows downward and is finally withdrawn from the bottom of the column.

[0042] The gas phase mixture at the top further enters the condensation mechanism through the opening and closing mechanism, and the separation of water and propanol is achieved through segmented condensation in the condensation mechanism. Among them, water is discharged, and propanol returns to reaction section one 12 in a liquid state for further reaction. Thus, while fully ensuring the conversion rate of the scheme, the interference of by-product water on the reaction process is reduced and the product purity of diacetone alcohol is improved.

[0043] On the other hand, the reaction section is slowly rotated through the rotation mechanism. The rotation rate of the slow rotation of the reaction section is synchronized with the rotation speed at the top of the rotation mechanism, which is 1 - 5 rpm. Along with the slow rotation of the reaction section, the positions of the liquid-phase propanol in the feed pipe 11 and the reflux pipe 34 when entering reaction section one 12 change synchronously, so as to avoid the accumulation of liquid-phase propanol on one side of reaction section one 12 during the period when the liquid-phase propanol has not been vaporized after entering reaction section one 12, ensuring uniform liquid-phase distribution in reaction section one 12 to avoid local high concentration or incomplete reaction, and thus improving the reaction efficiency of the scheme.

[0044] During the reaction, the liquid phase diacetone alcohol will entrain part of propanol and water when falling, and the propanol in the liquid phase will be vaporized and separated by heating in the distillation section 15, and then the water will be further evaporated and separated in the reboiler 16 to obtain high-purity diacetone alcohol; in this process, the rotating mechanism synchronously rotates and stirs the liquid phase in the reboiler 16, and the stirring accelerates the flow of the liquid phase, accelerates the evaporation of water to promote the separation of diacetone alcohol and water, reduces the residence time of diacetone alcohol in the high temperature area, and reduces the decomposition risk; at the same time, stirring can evenly distribute the heat in the reboiler 16, avoid local overheating and cause side reactions, and thus improve the purity of the product.

[0045] In the traditional reactive distillation process, the conversion rate of propanol is usually 90-95%, the purity of diacetone alcohol is about 95-98%, and there are many by-products. This scheme can effectively improve the conversion rate of propanol and the purity of diacetone alcohol through the reflux design of segmented condensation, the coaxial reverse stirring of the rotating mechanism, and the gas phase retention setting of the opening and closing mechanism, combined with segmented catalysis and low-pressure environment operation. The optimized propanol conversion rate can reach more than 99%, the purity of diacetone alcohol can reach more than 99%, and the by-products are reduced by more than 95%, and the energy consumption is reduced by 20-30%.

[0046] In the second embodiment, the opening and closing mechanism further comprises a sealing plate 22 arranged at the top of the flow guide 2, and the sealing plate 22 is fixedly connected to the inner wall of the distillation tower 1. The upper surface of the sealing plate 22 is limitedly penetrated by four positioning shafts 25 which are arranged around at equal intervals. The tops of the four positioning shafts 25 are penetrated by the same sealing plate 23, and the sealing plate 23 is fixedly connected to the inner wall of the distillation tower 1. The middle sections of the four positioning shafts 25 are fixedly connected to opening and closing arms 26, and the four opening and closing arms 26 are spliced ​​with each other. The outer contour of the opening and closing arm 26 is meshingly connected to a gear ring 24 located between the sealing plate 22 and the sealing plate 23.

[0047] The outer contour of the gear ring 24 is meshingly connected to a driving wheel 27 located outside the distillation tower 1. A protection frame 28 is provided on the outer contour of the driving wheel 27 and the protection frame 28 is fixedly connected to the outer wall of the distillation tower 1. An adjustment shaft 29 is fixedly connected to the center of the driving wheel 27 and the adjustment shaft 29 passes through the protection frame 28 and extends upward.

[0048] The centers of the sealing plates 1 22 and 23 are both provided with gas phase holes adapted to the top contour of the air deflector 2 . The adjustment shaft 29 is driven by an external motor, and the external motor is electrically connected to the pressure sensor 21 via a signal.

[0049] As can be seen from Embodiment 1, the opening and closing mechanism adjusts the gas flow to extend the residence time of propanol in the reaction section. Before the device starts working, an alarm threshold is preset for the pressure sensor 21. During the reaction process, the gas phase entering the flow guide cover 2 through the reaction section gradually increases. At this time, the opening and closing mechanism is in a closed state, resulting in a gradual increase in the pressure value monitored by the pressure sensor 21. When the pressure value exceeds the alarm threshold, the pressure sensor 21 sends a signal to the external motor of the adjusting shaft 29 and controls the adjusting shaft 29 to rotate. The adjusting shaft 29 further drives the driving wheel 27 and the gear ring 24 to rotate synchronously. The rotation of the gear ring 24 further causes the opening and closing arms 26 to deflect around the positioning shaft 25, and the movements of the four opening and closing arms 26 are synchronized. At this time, the combined states of the four opening and closing arms 26 are in contact, and gaps appear between the four opening and closing arms 26, thereby removing the blockage of the gas phase holes of the first sealing plate 22 and the second sealing plate 23. At this time, the mixture of vaporized propanol and water vapor gathered at the flow guide cover 2 enters the condensation mechanism through the gas phase holes, and the pressure value monitored by the pressure sensor 21 begins to decrease.

[0050] When the pressure value drops below the alarm threshold, the pressure sensor 21 sends a closing signal to the adjusting shaft 29. The adjusting shaft 29 rotates in reverse to drive the driving wheel 27 and the gear ring 24 to rotate synchronously in reverse. At this time, the opening and closing arms 26 start to reset around the positioning shaft 25. The four opening and closing arms 26 are again in a combined state and complete the blocking and closing operation of the gas phase holes of the first sealing plate 22 and the second sealing plate 23. In the closed state, the mixture of vaporized propanol and water vapor stays in the third reaction section 14 and reacts sufficiently under the action of the catalyst in the third reaction section 14, thereby effectively improving the conversion rate of the solution.

[0051] On the other hand, the size of the opening and closing gap between the four opening and closing arms 26 directly determines the flow rate of the gas phase from the rectification column 1 into the condensation mechanism. By placing the adjusting shaft 29 and the driving wheel 27 outside the rectification column 1, it is convenient for personnel to manually calibrate the gas phase flow rate.

[0052] Embodiment 3, the condensation mechanism includes a condensation group 3 provided on one side outside the rectification column 1. Inside the condensation group 3, there is a first condenser 32 and a second condenser 33, and the first condenser 32 is unidirectionally connected to the second condenser 33. There is a unidirectional connection between the top of the rectification column 1 and the first condenser 32 through a gas phase pipe 31. There is a unidirectional connection between the second condenser 33 and the first reaction section 12 through a return pipe 34 that penetrates the side of the rectification column 1;

[0053] The temperature of the first condenser 32 is set to 50 - 55 °C, and the temperature of the second condenser 33 is set to 0 - 10 °C.

[0054] It can be seen from Example 1 and Example 2 that the gas phase entering the condensing mechanism is a mixture of vaporized propanol and water vapor. At this time, the gas phase enters the condenser 32 through the gas phase pipe 31. Since the condensing mechanism is in a connected state with the distillation tower 1, that is, the condensing mechanism is also in a low-pressure environment of 20 to 25 kPa, the temperature of the condenser 32 is 50 to 55°C at this time, which can effectively condense the water vapor while keeping the propanol in a vaporized state, thereby realizing the separation of propanol and water. After separation, the liquid water is discharged to the outside through the discharge pipe 35, and the vaporized propanol enters the condenser 33 and is condensed into a liquid phase and refluxes into the reaction section 12 along the reflux pipe 34 to start the reaction again.

[0055] It should be noted that corresponding control valves are provided on the feed pipe 11, the discharge pipe 35 and the extraction pipe 17 to maintain a low pressure environment of 20-25 kPa inside the distillation tower 1 and the condensation mechanism.

[0056] In the fourth embodiment, the rotating mechanism further comprises a cross shaft 41 fixedly connected to the inner contour of the fixing ring 4, the top end of the cross shaft 41 penetrates and is rotatably connected to a bevel gear 1 42, and the bevel gear 1 42 is fixedly connected to the lower surface of the reaction section 12, both sides of the cross shaft 41 penetrate and are rotatably connected to a bevel gear 2 43 with opposite directions, the bottom end of the cross shaft 41 penetrates and is rotatably connected to a bevel gear 3 44, the bottom end of the bevel gear 3 44 is fixedly connected to a differential 45, and the differential 45 is rotatably connected to the center of the distillation section 15, the bottom end of the differential 45 is fixedly connected to a rotating shaft 46, and the outer contour of the rotating shaft 46 is provided with paddles 47.

[0057] The two bevel gears 2 43 are meshed and connected with bevel gear 1 42 and bevel gear 3 44. The rotating shaft 46 and the paddle 47 are located inside the reboiler 16. The bevel gear 1 42 is driven by a built-in low-speed motor. The rotation speed of the bevel gear 1 42 is 1 to 5 rpm. The amplification ratio of the differential 45 is 1 to 50, and the rotation speed of the rotating shaft 46 is 50 to 250 rpm.

[0058] As can be seen from the first embodiment, the rotating mechanism drives the reaction section to rotate slowly while completing the stirring of the liquid phase in the reboiler 16. The reaction section 12 rotates slowly to ensure that the liquid propanol that has not yet been vaporized is evenly distributed therein to improve the reaction efficiency and ensure that the propanol reacts fully. At the same time, the liquid phase in the reboiler 16 is stirred to accelerate the evaporation of water, reduce the residence time of diacetone alcohol in the high temperature area, and avoid its decomposition or the occurrence of side reactions.

[0059] After the device starts to work, the first bevel gear 42 starts to rotate on its own under the drive of the built-in low-speed motor. Since the first bevel gear 42 is fixedly connected to the first reaction section 12, and the first reaction section 12, the second reaction section 13, and the third reaction section 14 are fixedly connected in sequence, that is, the first bevel gear 42 starts to drive the whole reaction section to rotate synchronously at a low speed. The rotation speed of the whole reaction section is synchronously 1-5 rpm, which is dynamically adjusted according to the continuous input amount of propanol within the set range. The low-speed rotation of the first reaction section 12 causes the positions of the liquid-phase propanol in the feed pipe 11 and the reflux pipe 34 to change synchronously when they enter the first reaction section 12, thereby avoiding local high concentration or incomplete reaction caused by uneven liquid-phase distribution in the first reaction section 12.

[0060] At the same time, the rotation of the first bevel gear 42 drives the third bevel gear 44 to rotate synchronously under the transmission of the second bevel gear 43, and the rotation direction of the third bevel gear 44 is opposite to that of the first bevel gear 42. The rotation of the third bevel gear 44 further drives the rotating shaft 46 to rotate synchronously through the differential 45. After being amplified by the differential 45, the speed ratio between the third bevel gear 44 and the rotating shaft 46 reaches 1:50. The rotating shaft 46 further drives the paddle 47 to rotate. At this time, the rotation speeds of the rotating shaft 46 and the paddle 47 reach 50-250 rpm, and the paddle 47 fully stirs the liquid phase in the reboiler 16. The separated high-purity diacetone alcohol is discharged through the extraction pipe 17 for collection.

[0061] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A continuous reaction distillation device for synthesizing diacetone alcohol, comprising a distillation tower (1), characterized in that: The distillation tower (1) further comprises an opening and closing mechanism, a condensing mechanism and a rotating mechanism. A feed pipe (11) is connected to one side of the distillation tower (1). A reaction section three (14), a reaction section two (13), a reaction section one (12), a stripping section (15) and a reboiler (16) are arranged in sequence from top to bottom inside the distillation tower (1). The reaction section one (12), the reaction section two (13) and the reaction section three (14) are fixedly connected in sequence and are connected to the inner wall of the distillation tower (1) in a limited rotation manner. The feed pipe (11) is connected to the reaction section one (12) in one direction. The stripping section (15) and the reboiler (16) are fixedly connected and are fixedly connected to the inner wall of the distillation tower (1). A withdrawal pipe (17) is passed through the bottom end of the distillation tower (1) and the reboiler (16) is connected to the withdrawal pipe (17) in one direction. The opening and closing mechanism is arranged at the top of the distillation tower (1), and comprises a flow guide cover (2) fixedly connected to the outer periphery of the upper surface of the reaction section three (14) and a pressure sensor (21) fixedly connected to the center of the upper surface of the reaction section three (14); The condensing mechanism comprises a condensing group (3) arranged on one side of the outside of the distillation tower (1), wherein a condenser 1 (32) and a condenser 2 (33) are arranged inside the condensing group (3), and the condenser 1 (32) is connected to the condenser 2 (33) in one direction, a gas phase pipe (31) is connected to the top of the distillation tower (1) in one direction to the condenser 1 (32), and a reflux pipe (34) that runs through the side of the distillation tower (1) is connected to the condenser 2 (33) in one direction to the reaction section 1 (12); The rotating mechanism realizes uniform distribution of the liquid phase in the reaction section and sufficient mixing of the liquid phase in the bottom of the tower, and comprises a fixed ring (4) penetrating through and fixedly connected to the center of the stripping section (15); The absolute operating pressure of the distillation tower (1) is 20-25 kPa, the tower top temperature is 60-65°C, the tower bottom temperature is 90-100°C, and the space velocity of the distillation tower (1) is: ; The reaction section one (12), the reaction section two (13) and the reaction section three (14) are combined into a reaction section. The temperature of the reaction section is 70 to 80°C. The reaction section is filled with a catalytic filler and the catalyst in the catalytic filler is a hydroxide-type macroporous alkaline resin. The reaction section one (12) is filled with 828 resin, and the reaction section two (13) and the reaction section three (14) are filled with D296 resin.

2. The continuous reactive distillation equipment for synthesizing diacetone alcohol according to claim 1, characterized in that: The opening and closing mechanism further comprises a sealing plate 1 (22) arranged at the top of the flow guide cover (2), and the sealing plate 1 (22) is fixedly connected to the inner wall of the distillation tower (1); the upper surface of the sealing plate 1 (22) is limitedly penetrated by four positioning shafts (25) which are arranged around at equal intervals; the tops of the four positioning shafts (25) are penetrated by the same sealing plate 2 (23), and the sealing plate 2 (23) is fixedly connected to the inner wall of the distillation tower (1); the middle sections of the four positioning shafts (25) are fixedly connected to opening and closing arms (26), and the four opening and closing arms (26) are spliced ​​with each other; the outer contour of the opening and closing arm (26) is meshingly connected to a gear ring (24) located between the sealing plate 1 (22) and the sealing plate 2 (23); The outer contour of the gear ring (24) is meshingly connected to a driving wheel (27) located outside the distillation tower (1); a protection frame (28) is provided on the outer contour of the driving wheel (27), and the protection frame (28) is fixedly connected to the outer wall of the distillation tower (1); an adjustment shaft (29) is fixedly connected to the center of the driving wheel (27), and the adjustment shaft (29) passes through the protection frame (28) and extends upward.

3. The continuous reactive distillation equipment for synthesizing diacetone alcohol according to claim 2, characterized in that: The centers of the sealing plate 1 (22) and the sealing plate 2 (23) are both provided with gas phase holes adapted to the top profile of the air guide cover (2). The adjustment shaft (29) is driven by an external motor, and the external motor is connected to the pressure sensor (21) via a signal.

4. The continuous reactive distillation equipment for synthesizing diacetone alcohol according to claim 1, characterized in that: The temperature of the condenser 1 (32) is set to 50-55°C, and the temperature of the condenser 2 (33) is set to 0-10°C.

5. The continuous reactive distillation equipment for synthesizing diacetone alcohol according to claim 1, characterized in that: The rotating mechanism further comprises a cross shaft (41) fixedly connected to the inner contour of the fixing ring (4); the top end of the cross shaft (41) is penetrated by a bevel gear 1 (42) and is rotatably connected thereto, and the bevel gear 1 (42) is fixedly connected to the lower surface of the reaction section 1 (12); both sides of the cross shaft (41) are penetrated by a bevel gear 2 (43) with opposite directions and is rotatably connected thereto; the bottom end of the cross shaft (41) is penetrated by a bevel gear 3 (44) and is rotatably connected thereto; the bottom end of the bevel gear 3 (44) is fixedly connected to a differential (45) and the differential (45) is rotatably connected to the center of the stripping section (15); the bottom end of the differential (45) is fixedly connected to a rotating shaft (46), and a blade (47) is provided on the outer contour of the rotating shaft (46).

6. The continuous reactive distillation equipment for synthesizing diacetone alcohol according to claim 5, characterized in that: The two bevel gears 2 (43) are meshed and connected with bevel gear 1 (42) and bevel gear 3 (44). The rotating shaft (46) and the blades (47) are located inside the reboiler (16). The bevel gear 1 (42) is driven by a built-in low-speed motor. The rotation speed of the bevel gear 1 (42) is 1 to 5 rpm. The amplification ratio of the differential (45) is 1 to 50. The rotation speed of the rotating shaft (46) is 50 to 250 rpm.

Images