An esterification phase separator for preparing triacetin

Abstract

The present invention relates to the technical field of preparation of triacetin, specifically to an esterification phase separator for preparing triacetin, comprising a tower plate arranged inside a distillation tower, an umbrella-shaped cover evenly distributed on the upper surface of the tower plate, and the tower plate comprising a moving plate, a fixed plate, an air riser and an adjusting mechanism. The present invention solves the problems of viscous layer and mist entrainment caused by the high viscosity of triacetin by optimizing the design of the umbrella-shaped cover structure and the adjusting mechanism, expands the liquid material flow space and reduces the liquid residence time by reducing the bottom diameter of the umbrella-shaped cover and lowering the comprehensive height of the overflow weir, increases the gas phase flow area by providing an air inlet groove and adjusting the hydraulic cylinder, optimizes the gas-liquid contact, reduces the mist entrainment, and realizes the adaptation to the requirements of different reaction stages through the adjustment of the hydraulic cylinder, and increases the height of the downcomer plate to reduce the risk of liquid flooding.

Description

Technical Field

[0001] The invention relates to the technical field of triacetin preparation, in particular to an esterification phase separator for preparing triacetin. Background Art

[0002] Esterification phase separation refers to the phase separation phenomenon caused by the difference in physical properties between different components during or after the esterification reaction. The esterification reaction of triacetin is usually carried out in an esterification kettle. The raw materials glycerol (propylene glycol) and acetic acid (acetic acid) are heated and reacted under the action of an acidic catalyst. The generated water is evaporated and taken away by heating and / or decompression to obtain a semi-finished product. In this process, the esterification reaction is reversible. In order to promote the reaction in the positive direction, the generated water needs to be continuously removed. After the esterification reaction is completed, the crude triacetin obtained will contain unreacted raw materials, catalysts and other impurities. At this time, it is necessary to use a distillation tower to separate and purify the components. Industrial distillation towers have strong processing capacity and high separation efficiency, and are suitable for large-scale production. When the production scale of crude triacetin is large and efficient and continuous material separation is required, industrial distillation towers will be used. Due to the temperature difference in the distillation tower, each component will volatilize and condense at different positions in the tower according to its volatility or vapor pressure.

[0003] The purification process of crude triacetin mainly relies on distillation technology, in which key equipment such as reboiler, distillation tower, condenser and reflux tank work together to achieve effective separation of components. Figure 1 , the process starts with the reboiler, which is located at the bottom of the distillation tower as a heat exchange device. It partially vaporizes the liquid at the bottom of the tower by providing heat to it, and produces rising steam. These vapors carry different components in the crude triacetin, and then come into countercurrent contact with the descending condensate inside the distillation tower. As the vapors rise, they gradually cool and partially condense, while releasing heat. These condensates then descend along the tower plates, contacting and exchanging with the rising vapor again. When the vapors reach the top of the distillation tower, they are sent to the condenser for condensation. The condenser is usually located near the top of the tower, and the vapor is condensed into liquid by cooling water or other cooling media. The condensed liquid is collected in the reflux drum. Part of the liquid is sent back to the distillation tower as reflux liquid.

[0004] Due to its high viscosity, the fluidity of crude triacetin on the tray is relatively poor compared with other raw materials. This high viscosity not only causes the liquid to easily accumulate on the tray surface, channels and narrow tooth gaps of the bubble tray to form a viscous layer (please refer to Figure 2), which hinders the effective contact and mass transfer between the gas and liquid phases. When the gas flow rate increases, due to the high viscosity of the liquid, the droplets or liquid film are more easily torn by the high-speed airflow to form fine droplets. In addition, the tooth gap of the original bell-shaped bubble is located on the lower circumferential surface of the bubble, the tooth gap is perpendicular to the tower plate, and the tooth gap is fine. The fine tooth gap design on the bubble tower plate effectively increases the contact area and contact time between the gas and liquid phases. When the droplets pass through the tooth gap of the bubble, they will be deformed and broken due to obstruction, and more droplets will be released again. These droplets are then carried away by the airflow to form mist entrainment. The mist entrainment will bring the liquid droplets from the lower tower plate to the upper tower plate. These droplets contain heavy components. When these droplets containing heavy components are brought to the top of the tower, the content of heavy components in the top product will increase, thereby reducing the purity of triacetin.

[0005] Therefore, an esterification phase separator for preparing triacetin is proposed. Summary of the invention

[0006] The object of the present invention is to provide an esterification phase separator for preparing triacetin. In order to solve the problem that crude triacetin is easily accumulated at the gaps between the tower plates and bubble cap teeth due to its high viscosity and affects the gas-liquid mass transfer, and the high-speed airflow is easy to tear the droplets to form mist entrainment, an "umbrella"-shaped cover and a double-layer tower plate are designed to expand the flow range of the liquid material. According to production needs, the spacing between the plates and the weir height are adjusted to improve the contact efficiency of the gas-liquid two phases and reduce the mist entrainment problem.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An esterification phase separator for preparing triacetin, comprising a tower plate arranged inside a distillation tower, an umbrella-shaped cover evenly distributed on the upper surface of the tower plate, the tower plate comprising a moving plate, a fixed plate, a riser and an adjusting mechanism, the moving plate is located at the lower end of the fixed plate, a fixed-height overflow weir is arranged on one side end of the moving plate, a dynamic-height overflow weir is arranged on one side end of the fixed plate, a downcomer is arranged on the inner side of the dynamic-height overflow weir, the riser is evenly distributed on the upper surface of the moving plate, the adjusting mechanism is located between the moving plate and the fixed plate, the dynamic-height overflow weir is located on the inner side of the fixed-height overflow weir, the umbrella-shaped cover comprises a cover cap, a cover handle, a cover cavity, a tube cavity and an air inlet groove, the cover cap is installed at the upper end of the cover handle, the cover cavity is opened inside the cover cap, the tube cavity is opened inside the cover handle, and the air inlet groove is opened on the inner inclined surface of the cover cap;

[0009] The flow range of the liquid on the tower plate is expanded by the diameter difference between the cover cap and the cover handle, the liquid amount on the tower plate is controlled by adjusting the combined height of the fixed-height overflow weir and the dynamic-height overflow weir, the downcomer in the opposite direction of the fixed-height overflow weir controls the flow rate of the liquid entering the lower tower plate, and the liquid is guided by the fixed-height overflow weir and the dynamic-height overflow weir to flow to the next tower plate.

[0010] It can be seen from the above scheme that in the esterification process of preparing triacetin, traditional technology will adopt a relatively simple tower plate structure, such as a flat tower plate or a traditional tower plate system with a fixed overflow weir. The tower plates in the prior art often lack the ability to dynamically adjust the flow range and flow rate of the liquid, resulting in uneven distribution of the liquid on the tower plate, affecting the efficiency of the esterification reaction and product quality. In contrast, this scheme adopts a tower plate design with an umbrella cover and an adjustable overflow weir, which significantly improves the reaction efficiency and product quality by optimizing the liquid distribution, flexible quantity control and precise speed regulation.

[0011] Preferably, a movable plate groove is provided inside the fixed height overflow weir, and the movable plate groove matches the downcomer plate.

[0012] From the above scheme, it can be seen that a movable plate trough matching the downcomer is opened inside the fixed-height overflow weir. In the prior art, a combination of a fixed overflow weir and a downcomer is used to complete the installation. Compared with the prior art, this scheme achieves precise regulation of liquid flow through the matching design of the movable plate trough and the downcomer, improves reaction efficiency, product quality and tray stability, and reduces operational risks.

[0013] Preferably, the lower surface of the fixed plate is evenly provided with docking grooves, and the docking grooves match the riser pipes.

[0014] It can be seen from the above scheme that the lower surface of the fixed plate is evenly provided with docking grooves matching the riser. In the prior art, a simple perforation or a method of directly fixing the riser on the fixed plate is adopted. Compared with the prior art, this scheme ensures the precise installation and stability of the riser through the docking groove design, optimizes the gas-liquid flow, and improves the operation efficiency and product quality of the tower plate.

[0015] Preferably, the top end height of the riser is higher than the fixed-height overflow weir, and the upper port position of the tube cavity is higher than the dynamic-height overflow weir.

[0016] From the above scheme, it can be seen that the top height of the riser is designed to be higher than the fixed-height overflow weir, and the upper port position of the tube cavity is also higher than the dynamic-height overflow weir. In the prior art, a riser and overflow weir of uniform height are used. Compared with the prior art, this scheme optimizes the gas-liquid flow path of the tray, ensures that the height of the riser is higher than the overflow weir, effectively prevents gas-liquid mixing, and improves operational stability, separation efficiency, and product quality.

[0017] Preferably, the air inlet slot is a structure of four open slots, and the slot openings are distributed in a ring shape.

[0018] It can be seen from the above scheme that the air inlet slot is designed as a four-open slot structure, and the slot openings are distributed in a ring shape. In the prior art, a single open slot or multiple open slots with irregular distribution are used as an alternative. Compared with the prior art, this scheme effectively guides the airflow through four open slots distributed in a ring shape, improves the uniformity of gas-liquid contact and reaction efficiency, reduces energy consumption and noise, and improves the overall performance of the equipment.

[0019] Preferably, the adjustment mechanism includes a hydraulic cylinder, a lifting assembly and a handle rod. The hydraulic cylinder is arranged at one side end between the moving plate and the fixed plate. One end of the hydraulic cylinder is connected to the tower wall, and one lifting assembly is connected to the other end of the hydraulic cylinder. The lifting assemblies are connected by a handle rod.

[0020] It can be seen from the above scheme that the adjustment mechanism adopts a combination design of a hydraulic cylinder, a lifting component and a handle rod. In the prior art, a mechanical adjustment mechanism (such as a lead screw, a nut, etc.) or a pneumatic adjustment mechanism is used. Compared with the prior art, this scheme ensures accurate and smooth adjustment of the moving plate and the fixed plate through the robust design of the hydraulic cylinder, the lifting component and the handle rod, thereby improving the performance of the equipment and extending its service life.

[0021] Preferably, the lifting assembly includes an outer ring, a push block, a fixed handle ring and an extrusion bevel groove, the fixed handle ring is sleeved on the circumferential surface of the riser, the extrusion bevel groove is opened on one side vertical surface of the fixed handle ring, the outer ring is sleeved on the outside of the fixed handle ring, the push block is installed on the inner surface of the outer ring, and the push block is connected to the extrusion bevel groove.

[0022] It can be seen from the above scheme that the lifting assembly adopts a combination design of an outer ring, a push block, a fixed handle ring and an extrusion chute. In the prior art, a simple lifting rod or a slider mechanism is used as an alternative. Compared with the prior art, this scheme ensures stable and precise adjustment of the moving plate and the fixed plate through the precise docking design of the fixed handle ring, the extrusion chute and the push block, optimizes the gas-liquid flow, and improves the reaction efficiency and product quality.

[0023] Preferably, one end of the push block is provided with a chamfered surface, and the chamfered surface corresponds to the inner side chamfer of the extrusion chute.

[0024] It can be seen from the above scheme that one end of the push block is designed as a bevel surface, which corresponds to the inner bevel surface of the extrusion chute. In the prior art, a right-angle push block or a combination of a flat push block and a vertical notch is used as an alternative. Compared with the prior art, this scheme makes the push block fit closely with the extrusion chute through the bevel surface design, improves the adjustment accuracy and stability, optimizes the equipment performance, prolongs the service life, and ensures the precise adjustment of the gas-liquid flow of the tower plate.

[0025] Preferably, a movable groove is provided at one end of the handle rod farthest from the hydraulic cylinder, and two arm rods are connected and installed in the movable groove. One end of one of the arm rods is provided with a movable connecting part 1, and one end of the other arm rod is provided with a movable connecting part 2. The movable connecting part 1 is arranged on the inner surface of the fixed height overflow weir, and the movable connecting part 2 is arranged on the inner surface of the liquid drop plate.

[0026] It can be seen from the above scheme that the movable groove at one end of the handle is connected to two arm rods, which are respectively connected to the fixed height overflow weir and the liquid drop plate through movable connecting parts. In the prior art, a rigid connecting rod or a fixed hinge is used. Compared with the prior art, this scheme gives the fixed height overflow weir and the liquid drop plate fine-tuning freedom through the design of the movable groove, arm rod and movable connecting part, optimizes the flow of liquid materials, enhances the connection stability, and improves the equipment performance, reaction efficiency and product quality.

[0027] Preferably, an open groove is provided on the inner surface of the fixed-height overflow weir, and the open groove corresponds to the second position of the movable connecting member.

[0028] It can be seen from the above scheme that an open groove corresponding to the second position of the movable connecting piece is provided on the inner surface of the fixed height overflow weir. In the prior art, the connecting piece is directly fixed on the fixed height overflow weir or connected by welding or other methods. Compared with the prior art, this scheme simplifies the installation and fine-tuning of the movable connecting piece through the open groove design, enhances the connection stability, avoids structural stress, improves the performance and life of the equipment, and provides reliable support for the esterification process.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. An esterification phase separator for preparing triacetin, which expands the flow space of liquid on the tower plate by narrowing the diameter of the bottom end of the umbrella cover and optimizing the tower plate structure. At the same time, the combined height of the fixed-height overflow weir and the dynamic-height overflow weir is reduced, which effectively reduces the residence time of the liquid on the tower plate and improves the distribution performance of the liquid, so that the liquid can pass through the channels between the bubble caps more smoothly, reducing the viscous layer problem caused by the high viscosity of triacetin, thereby improving the distillation efficiency and product quality.

[0031] 2. An esterification phase separator for preparing triacetin, the air inlet slot design of the umbrella-shaped cover adopts four wide-mouth outlets, which provides a larger gas phase flow area, allowing the gas phase to flow out of the tower plate more smoothly, reducing the turbulence and eddy currents caused by excessive flow resistance, while extending the rotation length of the gas phase in the liquid, increasing the contact area between the gas and the liquid, and improving the mass transfer efficiency. In addition, the smooth gas phase flow and uniform distribution help to reduce the entrainment of mist and foam, thereby maintaining the gas-liquid equilibrium state on the tower plate and further improving the distillation effect.

[0032] 3. An esterification phase separator for preparing triacetin can flexibly adjust the combined height of the fixed-height overflow weir and the dynamic-height overflow weir through the synergistic effect of the hydraulic cylinder and the lifting assembly, so that the gas-liquid separation efficiency of each layer of the tower plate can be accurately controlled according to actual needs, thereby improving the controllability and flexibility of the entire distillation process. In addition, by adjusting the height of the downcomer, the flow path of the liquid is further optimized, the risk of flooding is reduced, and the stability and safety of the distillation process are ensured, which together promotes the efficient preparation and purification of triacetin. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the distillation system of the present invention;

[0034] Figure 2 It is a structural schematic diagram of a distillation tower of the present invention;

[0035] Figure 3 It is a schematic diagram of the overall structure of the tower tray of the present invention;

[0036] Figure 4 It is a plane schematic diagram of the umbrella cover of the present invention;

[0037] Figure 5 It is a schematic diagram of the distribution of umbrella-shaped covers of the present invention;

[0038] Figure 6 It is a schematic diagram of the bottom of the tower tray of the present invention;

[0039] Figure 7 It is a schematic diagram of the structure of the regulating mechanism of the present invention;

[0040] Figure 8 It is a schematic diagram of the riser structure of the present invention.

[0041] In the figure:

[0042] 100, tray;

[0043] 1. Tower plate; 11. Moving plate; 12. Fixed plate; 121. Docking groove; 13. Riser; 14. Adjusting mechanism; 141. Hydraulic cylinder; 142. Lifting assembly; 1421. Outer ring; 1422. Push block; 1423. Fixed handle ring; 1424. Extrusion chute; 143. Handle rod; 144. Active connection part 1; 145. Open groove; 146. Active connection part 2; 147. Arm rod; 148. Active groove; 2. Umbrella cover; 21. Cover cap; 22. Cover handle; 23. Cover cavity; 24. Tube cavity; 25. Inlet groove; 3. Fixed height overflow weir; 31. Active plate groove; 4. Dynamic height overflow weir; 5. Downcomer;

[0044] 200, distillation tower;

[0045] 6. Air outlet; 7. Reflux port; 8. Feed port; 9. Air inlet; 10. Discharge port;

[0046] 300, reboiler;

[0047] 400, condenser;

[0048] 500. Reflux tank. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] See also Figures 1 to 8 The present invention provides an esterification phase separator for preparing triacetin, and the technical scheme is as follows:

[0051] An esterification phase separator for preparing triacetin, comprising a tray 1 arranged inside a distillation tower 200, an umbrella-shaped cover 2 evenly distributed on the upper surface of the tray 1, the tray 1 comprising a moving tray 11, a fixed tray 12, a riser 13 and an adjusting mechanism 14, the moving tray 11 is located at the lower end of the fixed tray 12, a fixed height overflow weir 3 is arranged on one side end of the moving tray 11, a dynamic height overflow weir 4 is arranged on one side end of the fixed tray 12, a downcomer 5 is arranged on the inner side of the dynamic height overflow weir 4, the riser 13 is evenly distributed on the upper surface of the moving tray 11, the riser 13 corresponds to the umbrella-shaped cover 2 one by one, the adjusting mechanism 14 is located between the moving tray 11 and the fixed tray 12, the dynamic height overflow weir 4 corresponds to the fixed height overflow weir 4, and the downcomer 5 is arranged on the inner side of the dynamic height overflow weir 4. The high overflow weir 3 is fitted and connected, and the dynamic high overflow weir 4 is located on the inner side of the fixed high overflow weir 3. The umbrella-shaped cover 2 includes a cover cap 21, a cover handle 22, a cover cavity 23, a tube cavity 24 and an air inlet groove 25. The cover handle 22 is connected to the upper surface of the fixed plate 12. The cover cap 21 is installed at the upper end of the cover handle 22. The cover cavity 23 is opened inside the cover cap 21. The tube cavity 24 is opened inside the cover handle 22. The tube cavity 24 is movably connected to the riser 13. The air inlet groove 25 is opened on the inner slope of the cover cap 21. Multiple layers of trays 1 are arranged inside the distillation tower 200. The fixed high overflow weir 3, the dynamic high overflow weir 4 and the downcomer 5 of each layer of tray 1 are relatively positioned to guide the liquid material.

[0052] The flow range of the liquid on the tray 1 is expanded by the diameter difference between the cap 21 and the cover handle 22. The displacement of the moving plate 11 relative to the fixed plate 12 drives the fixed height overflow weir 3 to rise and fall. The liquid volume on the tray 1 is controlled by adjusting the combined height of the fixed height overflow weir 3 and the dynamic height overflow weir 4. The downcomer 5 in the opposite direction of the displacement of the fixed height overflow weir 3 controls the flow rate of the liquid entering the lower tray 1. The liquid is guided by the fixed height overflow weir 3 and the dynamic height overflow weir 4 to flow to the next tray 1. The continuous steam is guided by the riser 13 to the position of the air inlet groove 25 to mix with the liquid on the tray 1. The gas phase rises layer by layer from bottom to top. The tray 1 design with an umbrella cover 2 and an adjustable overflow weir has significant advantages. First, the diameter difference between the cap 21 and the cover handle 22 of the umbrella cover 2 effectively expands the flow range of the liquid on the tray 1, so that the liquid can be more evenly distributed on the tray 1, thereby improving the reaction efficiency and product quality. Secondly, by adjusting the combined height of the fixed-height overflow weir 3 and the dynamic-height overflow weir 4 through the regulating mechanism 14, the amount of liquid on the tray 1 can be flexibly controlled, further optimizing the reaction conditions. In addition, the design of the downcomer 5 in the opposite direction of displacement to the fixed-height overflow weir 3 can accurately control the flow rate of the liquid entering the lower tray 100, avoiding excessive accumulation or rapid flow of the liquid between the trays 100, thereby ensuring the stability and controllability of the reaction.

[0053] In this embodiment, reference Figure 1 and Figure 2 The feed port 8 is located in the middle or slightly below the tower, and is used to introduce crude triacetin. The discharge port 10 at the bottom of the tower is used to discharge heavy components, and the discharge port 10 at the top of the tower collects light components. The air inlet 9 is a channel for steam to rise. The air outlet 6 is located at the top of the tower, and is used to discharge the separated gas phase material to the condenser 400. The reflux port 7 connects the condenser 400 and the tower body, and is used to reflux part of the condensed liquid into the tower. After the crude triacetin enters the distillation tower 200 from the feed port 8, it flows from top to bottom through the tower plate 100 and enters the bottom of the tower. It is first heated by the reflux tank 500, which is located at the bottom of the tower. The heat vaporizes the liquid to form rising steam, which contacts the descending liquid flow in the tower in countercurrent, and realizes mass transfer and separation through gas-liquid exchange on the tower plate 100. The light component gradually rises and is enriched at the top of the tower, while the heavy component gradually descends and is enriched at the bottom of the tower. After the steam at the top of the tower enters the condenser 400, it is cooled by cooling water or other cooling media and condensed into liquid. The condenser 400 is located at the top of the tower to ensure that the steam can be fully condensed. The condensed liquid part enters the reflux tank 500. The gas-liquid contact area and time in the tower are controlled by adjusting the reflux ratio and the ratio of the reflux liquid volume to the produced liquid volume, thereby optimizing the separation effect. The other part of the liquid is produced as a product. The entire distillation process is carried out under continuous operation, and products of different purities are obtained at the bottom and top of the tower, respectively, and are collected and sent out of the distillation tower 200 through their respective discharge ports 10.

[0054] Crude triacetin has the characteristics of high viscosity. If the problem of mist entrainment is solved by a demister, the demister usually relies on the gravity sedimentation and inertial collision of the liquid to separate the mist, but in high-viscosity liquids, the effect of these mechanisms will be greatly reduced. Viscous liquids will slow down the movement of mist, reduce the frequency and intensity of its collision with the metal mesh of the demister, and thus reduce the efficiency of demister. Due to the high viscosity of triacetin, the mist is easy to form a thick liquid film on the demister, resulting in the blockage of the metal mesh of the demister, which will not only reduce the flux of the demister, but also cause equipment failure.

[0055] As an embodiment of the present invention, referring to FIG. Figure 3 , Figure 4 and Figure 8 A movable plate groove 31 is provided inside the fixed height overflow weir 3, and the movable plate groove 31 matches the downcomer 5. The design of the movable plate groove 31 allows the downcomer 5 to be adjusted more accurately according to actual needs, thereby more effectively controlling the flow of liquid between the trays 1. This dynamic adjustment capability not only improves the uniformity of liquid distribution, but also helps to optimize reaction conditions, improve reaction efficiency and product quality. In addition, the matching design of the movable plate groove 31 and the downcomer 5 also enhances the stability and reliability of the tray 1 structure, and reduces the operational risks caused by liquid accumulation or rapid flow.

[0056] In this embodiment, space is provided for adjusting the height of the downcomer 5, and the two side ends and the bottom end of the fixed height overflow weir 3 are open structures, the upper end surface will not be affected, and the two side ends of the fixed height overflow weir 3 can still be normally connected with the inner wall of the tower body.

[0057] As an embodiment of the present invention, refer to Figure 6 The lower surface of the fixed plate 12 is evenly provided with docking grooves 121, which match the riser 13. The design of the docking grooves 121 ensures that the riser 13 can be accurately inserted and fixed on the fixed plate 12, avoiding operational problems caused by position deviation or unstable fixation. At the same time, the docking grooves 121 also optimize the gas-liquid flow path, which helps to achieve more effective gas-liquid separation and improve the operating efficiency and product quality of the tower plate 1.

[0058] In this embodiment, one docking groove 121 corresponds to one lumen 24, and the diameters of the docking groove 121 and the lumen 24 are consistent, so the docking groove 121, the lumen 24 and the riser 13 are connected together, the riser 13 is height-adjusted inside the lumen 24 and the cover cavity 23, the lumen 24 limits the riser 13, and the cover cavity 23 is used to provide displacement space for the end of the riser 13.

[0059] As an embodiment of the present invention, refer to Figure 4The top of the riser 13 is higher than the fixed-height overflow weir 3, and the upper port of the tube cavity 24 is higher than the dynamic-height overflow weir 4. By optimizing the gas-liquid flow path inside the tray 1 and ensuring that the top of the riser 13 and the upper port of the tube cavity 24 are higher than the overflow weir, the liquid can be effectively prevented from entering the riser 13 or the tube cavity 24 during the flow process, thereby avoiding operational problems and product quality degradation caused by gas-liquid mixing. This design not only improves the operational stability of the tray 1, but also helps to improve the gas-liquid separation efficiency and product quality.

[0060] In this embodiment, the riser 13 and the fixed-height overflow weir 3 are displaced synchronously, while the tube cavity 24 and the dynamic-height overflow weir 4 are fixed in position, and there are two situations. When the top of the riser 13 is higher than the upper port of the tube cavity 24, the combined height of the dynamic-height overflow weir 4 and the fixed-height overflow weir 3 is lower than the upper port of the riser 13; when the top of the riser 13 is lower than the upper port of the tube cavity 24, the combined height of the dynamic-height overflow weir 4 and the fixed-height overflow weir 3 is lower than the upper port of the tube cavity 24, so that the liquid level is always below the riser 13 or the tube cavity 24 to avoid leakage.

[0061] As an embodiment of the present invention, refer to Figure 5 and Figure 6 The air inlet groove 25 is a four-open groove structure with an annular distribution of the grooves. The four annularly distributed open grooves can more effectively guide the airflow into the cover cavity 23, avoiding local accumulation or excessive flow of the airflow on the cover cap 21, thereby improving the uniformity of gas-liquid contact and reaction efficiency. In addition, this design also helps to reduce energy consumption and noise, and improve the overall performance of the equipment.

[0062] In this embodiment, the four opening slots of the air inlet slot 25 are separated only by thin strips, which maximizes the flow diameter of the gas phase, and the slot openings are distributed in an annular shape, so that the gas can be evenly delivered into the liquid in a smooth state.

[0063] As an embodiment of the present invention, refer to Figure 7 The adjustment mechanism 14 includes a hydraulic cylinder 141, a lifting component 142 and a handle 143. The hydraulic cylinder 141 is arranged at one side end between the moving plate 11 and the fixed plate 12. One end of the hydraulic cylinder 141 is connected to the tower wall, and a lifting component 142 is connected to the other end of the hydraulic cylinder 141. The lifting components 142 are connected through the handle 143. The hydraulic cylinder 141 provides driving force and stable adjustment performance, which can ensure accurate adjustment between the moving plate 11 and the fixed plate 12. At the same time, the design of the lifting component 142 and the handle 143 makes the adjustment process smoother and more controllable, avoiding adjustment errors caused by mechanical friction or pneumatic fluctuations. This design not only improves the overall performance of the equipment, but also helps to extend the service life of the equipment.

[0064] In this embodiment, the lift pipes 13 to which the plurality of lift assemblies 142 are connected are located on the dividing line of the movable plate 11 , that is, at the center of the movable plate 11 . The hydraulic cylinder 141 can stably control the lifting and lowering of the movable plate 11 as a whole.

[0065] As an embodiment of the present invention, refer to Figure 7 The lifting assembly 142 includes an outer ring 1421, a push block 1422, a fixed handle ring 1423 and an extrusion chute 1424. The fixed handle ring 1423 is sleeved on the circumferential surface of the riser 13. The extrusion chute 1424 is provided on a side elevation of the fixed handle ring 1423. The outer ring 1421 is sleeved on the outside of the fixed handle ring 1423. The push block 1422 is installed on the inner surface of the outer ring 1421. The push block 1422 is connected to the extrusion chute 1424. The fixed handle ring 1423 is sleeved on the riser 13. The extrusion chute 1424 is connected to the push block 1422, so that precise adjustment and stable support are achieved. The design of the outer ring 1421 and the push block 1422 makes the adjustment process smoother and avoids adjustment errors caused by mechanical friction or structural looseness. This design not only improves the overall performance of the equipment, but also helps to ensure precise adjustment between the moving plate 11 and the fixed plate 12, thereby optimizing the gas-liquid flow path inside the tower plate 1 and improving the reaction efficiency and product quality.

[0066] In this embodiment, the push block 1422 can only be raised and lowered inside the extrusion groove 1424, and the height of the push block 1422 inside the extrusion groove 1424 corresponds to the overall height of the movable plate 11, that is, the overall lifting displacement of the movable plate 11 is stably controlled by the left and right displacement of the hydraulic cylinder 141.

[0067] As an embodiment of the present invention, refer to Figure 1 One end of the push block 1422 is provided with a chamfered surface, which corresponds to the inner chamfer of the extrusion chute 1424. The design of the chamfered surface allows the push block 1422 and the extrusion chute 1424 to fit more closely during the adjustment process, reducing friction and resistance during adjustment and improving the accuracy and stability of adjustment. At the same time, this design also makes the adjustment process smoother, avoiding jamming or difficulty in adjustment due to structural mismatch. This optimization not only improves the overall performance of the equipment, but also helps to extend the service life of the equipment and ensures accurate adjustment of the gas-liquid flow path inside the tower plate 1.

[0068] In this embodiment, when the push block 1422 moves to the left, a certain space is generated between the push block 1422 and the extrusion bevel 1424. By utilizing the overall gravity of the movable disk 11, the movable disk 11 moves downward, and the push block 1422 and the extrusion bevel 1424 quickly fit tightly again; when the push block 1422 moves to the right, the extrusion bevel 1424 is subjected to the extrusion force of the push block 1422, and the push block 1422 will gradually slide along the lower end of the inclined side surface of the extrusion bevel 1424, then the movable disk 11 moves upward, and the push block 1422 and the extrusion bevel 1424 always keep in close fit.

[0069] As an embodiment of the present invention, refer to Figure 7 and Figure 8 , a movable groove 148 is provided at one end of the handle bar 143 farthest from the hydraulic cylinder 141, and two arm bars 147 are connected and installed on the movable groove 148, and a movable connecting piece 144 is provided at one end of one arm bar 147, and a movable connecting piece 2 146 is installed at one end of the other arm bar 147, and the movable connecting piece 144 is arranged on the inner surface of the fixed height overflow weir 3, and the movable connecting piece 2 146 is arranged on the inner surface of the downcomer plate 5. The design of the movable groove 148 and the arm bar 147 allows the fixed height overflow weir 3 and the downcomer plate 5 to have a certain degree of freedom during the adjustment process, and can be fine-tuned according to actual needs, thereby optimizing the flow path of the liquid on the tower plate 1. At the same time, the use of the movable connecting piece also enhances the stability and reliability of the connection, and avoids the structural stress concentration or damage caused by the rigid connection. This design not only improves the overall performance of the equipment, but also helps to ensure the precise control of the gas-liquid flow inside the tower plate 1, and improves the reaction efficiency and product quality.

[0070] In this embodiment, when the handle 143 moves to the left, the angle between the two arm rods 147 becomes smaller, and the height of the fixed-height overflow weir 3 is lowered and the height of the down-flow plate 5 is increased by utilizing the traction force of the two arm rods 147 on the fixed-height overflow weir 3 and the down-flow plate 5 respectively; when the handle 143 moves to the right, the angle between the two arm rods 147 becomes larger, the height of the fixed-height overflow weir 3 is increased, and the height of the down-flow plate 5 is reduced.

[0071] As an embodiment of the present invention, refer to Figure 7 The inner surface of the fixed height overflow weir 3 is provided with an open groove 145, and the open groove 145 corresponds to the position of the movable connecting piece 2 146. The design of the open groove 145 allows the movable connecting piece 2 146 to be more easily installed and fixed on the fixed height overflow weir 3, and also helps to make fine adjustments during the adjustment process to ensure the stability and reliability of the connection. In addition, this design also avoids structural stress or deformation caused by welding and the like, thereby extending the service life of the equipment. In summary, this technical solution improves the overall performance and adjustment flexibility of the equipment by optimizing the connection structure, and provides more reliable technical support for the esterification process of preparing triacetin.

[0072] In this embodiment, the open groove 145 provides a mounting area for the second movable connecting member 146 so that the arm 147 can exert a force on the downcomer plate 5 .

[0073] Working principle: In order to solve the problem of viscous layer and mist entrainment caused by the high viscosity of triacetin, the bubble structure is optimized, the bottom diameter of the umbrella cover 2 is narrowed to expand the liquid flow space, and the combined height of the fixed height overflow weir 3 and the dynamic height overflow weir 4 is reduced to reduce the liquid residence time and improve the liquid distribution. The four outlets of the air inlet groove 25 of the cover cap 21 are designed to increase the gas phase flow area, optimize the gas-liquid contact, reduce the mist entrainment, and adjust the overflow weir height through the hydraulic cylinder 141 to meet the needs of different reaction stages, and increase the height of the liquid drop plate 5.

[0074] Specifically, in order to solve the problem that the plate 100 near the feed port 8 is prone to produce a viscous layer due to the high viscosity of the raw material of triacetin and the narrow channel between the bubbles, refer to Figure 2 The diameter of the bottom of the bubble cap is narrowed by the cover handle 22, the flow space of the liquid is expanded, and the combined height of the fixed-height overflow weir 3 and the dynamic-height overflow weir 4 is reduced, the residence time of the liquid on the tower plate 100 is reduced, the distribution performance of the liquid is improved, and the liquid is more evenly distributed on the tower plate 100, thereby reducing the formation of the viscous layer. The specific process is as follows:

[0075] After the crude triacetin enters the interior of the distillation tower 200 from the feed port 8, it will flow on the tray 1 and accumulate in the cavity formed by the tower wall, the fixed height overflow weir 3 and the dynamic height overflow weir 4 and the tray 1, forming a certain liquid level. The volume of the bottom of the umbrella-shaped cover 2 is reduced by the cover handle 22, the accumulated liquid volume is increased, and the flow range is expanded. The resistance encountered by the liquid during the flow process is reduced, and the fluidity is improved, which helps the liquid to pass through the channel between the bubble caps more smoothly and reduce the formation of the viscous layer. When the liquid level exceeds the combined height of the fixed height overflow weir 3 and the dynamic height overflow weir 4, the liquid will flow from the downcomer 5 of the upper tray 1 to the liquid receiving tray of the lower tray 1, that is, the upper surface of the fixed tray 12, by the gravity of the liquid. By reducing the combined height of the fixed height overflow weir 3 and the dynamic height overflow weir 4, the efficiency of liquid distribution to the lower tray 1 is improved, thereby reducing the residence time of the viscous liquid on the tray 1. The shorter residence time further prevents the formation of the viscous layer.

[0076] In order to solve the problem that the tooth gap of the original bell-shaped blister is located on the lower circumference of the blister, refer to Figure 2The tooth gap is perpendicular to the bubble cap plate, and the tooth gap is fine. After the gas phase passes through the tube body and enters the rotation space between it and the bubble cap, it will directly form a bubbling contact with the liquid on the bubble cap plate at a certain ejection speed from the tooth gap. Due to the high viscosity of the liquid, the droplets or liquid film are more easily torn by the high-speed airflow to form fine droplets. When the droplets pass through the tooth gap of the bubble cap, they will be deformed and broken due to obstruction, releasing more droplets again. These droplets are then carried away by the airflow, and the entrained droplets will enter the next bubble cap plate with the gas phase, increasing the processing load of the next plate 100, so the problem of mist entrainment is formed. The specific solutions are as follows:

[0077] The design of opening four outlets through the air inlet slot 25 of the cap 21, the four outlets of the gas phase are wide-mouthed, the resistance of the gas phase passing through is small, a larger flow area is provided, so that the gas phase can flow out of the tower plate 1 more smoothly, and the turbulence and eddy current caused by excessive flow resistance are reduced. In addition, the gas phase faces downward at the outlet of the cap 21, and the gas phase has a wavy direction in the liquid, and the rotation length is extended. Figure 4 , increasing the contact area between gas and liquid, thereby improving the mass transfer efficiency. Compared with the vertical tooth gap of the original bell-shaped bubble, there is a gradient in the amount of gas phase passing through the tooth gap at different heights, and the amount of gas phase in contact with the liquid at the bottom of the bubble plate is small, which affects the gas-liquid mass transfer efficiency, which is also one of the reasons for the formation of the viscous layer. In the present invention, the flow direction of the gas phase in the liquid will produce a certain disturbance, thereby increasing the driving force for mass transfer and promoting the mixing between gas and liquid. The smooth flow and uniform distribution of the gas phase help to reduce the entrainment of mist, thereby maintaining the gas-liquid equilibrium state on the plate 100.

[0078] The crude triacetin has high viscosity and slow flow rate, and its residence time on the tray 100 is relatively long. In order to reduce the residence time of the viscous liquid on the tray 1, the combined height of the fixed-height overflow weir 3 and the dynamic-height overflow weir 4 will be reduced. The specific process is as follows: the hydraulic cylinder 141 drives the docked lifting assembly 142 to move to the left, and a gap is generated between the push block 1422 and the extrusion chute 1424. By utilizing the connection effect of the handle 143, multiple groups of lifting assemblies 142 are operated synchronously. By utilizing the slope difference of the inclined surface and the gravity of the moving plate 11, the moving plate 11 is displaced downward by a certain distance as a whole, and the fixed-height overflow weir 3 moves downward relative to the dynamic-height overflow weir 4, and the combined height of the fixed-height overflow weir 3 and the dynamic-height overflow weir 4 is reduced. The gas-liquid separation efficiency requirements of each layer of the tower plate 100 are different, so the weir height of each layer of the tower plate 100 is different, and in the later stage of the reaction, the concentration of the raw materials will become lower and lower, and the combined height of the fixed height overflow weir 3 and the dynamic height overflow weir 4 needs to be adjusted accordingly, and then the height of the overflow weir is adjusted accordingly according to the reaction requirements through the hydraulic cylinder 141, and the controllability is relatively high.

[0079] Because the moving plate 11 and the fixed height overflow weir 3 are an integrated structure, when the height of the fixed height overflow weir 3 is reduced, the inter-plate spacing between the upper moving plate 11 and the lower fixed plate 12 will become smaller. For the mist entrainment phenomenon, the smaller spacing will slow down the speed of the gas, which is conducive to the recapture of the tiny droplets of mist in the gas by the liquid. In order to avoid liquid flooding, by raising the height of the downcomer plate 5, the liquid can flow more smoothly to the next tower plate 1, thereby reducing the risk of liquid flooding. The specific operation is as follows: refer to Figure 4 and Figure 7 When the multiple lifting assemblies 142 move to the left, the two arm rods 147 are subjected to traction, the angle between the two becomes smaller, and the distance between the movable connecting member 144 and the movable connecting member 2 146 becomes smaller, then the downcomer 5 moves upward along the inside of the movable plate groove 31, and the height of the bottom of the downcomer 5 is increased, thereby allowing a larger liquid flow to pass through the next layer of the tower plate 1.

[0080] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An esterification phase separator for preparing triacetin, comprising a tray (1) arranged inside a distillation tower, characterized in that: The upper surface of the tower plate (1) is evenly distributed with an umbrella-shaped cover (2). The tower plate (1) comprises a moving plate (11), a fixed plate (12), an air riser (13) and an adjustment mechanism (14). The moving plate (11) is located at the lower end of the fixed plate (12). A fixed-height overflow weir (3) is provided at one side end of the moving plate (11). A dynamic-height overflow weir (4) is provided at one side end of the fixed plate (12). A downcomer (5) is provided on the inner side of the dynamic-height overflow weir (4). The air riser (13) is evenly distributed on the moving plate (11). 11), the adjustment mechanism (14) is located between the movable plate (11) and the fixed plate (12), the umbrella-shaped cover (2) comprises a cover cap (21), a cover handle (22), a cover cavity (23), a tube cavity (24) and an air inlet groove (25), the cover cap (21) is mounted on the upper end of the cover handle (22), the cover cavity (23) is opened inside the cover cap (21), the tube cavity (24) is opened inside the cover handle (22), and the air inlet groove (25) is opened on the inner inclined surface of the cover cap (21); The adjustment mechanism (14) comprises a hydraulic cylinder (141), a lifting assembly (142) and a handle rod (143); the hydraulic cylinder (141) is arranged at one side end between the moving plate (11) and the fixed plate (12); one end of the hydraulic cylinder (141) is connected to the tower wall; one of the lifting assemblies (142) is connected to the other end of the hydraulic cylinder (141); and the lifting assemblies (142) are connected to each other via the handle rod (143); A movable groove (148) is formed at one end of the handle bar (143) farthest from the hydraulic cylinder (141), and two arm bars (147) are connected and installed to the movable groove (148); one end of one of the arm bars (147) is provided with a movable connecting piece 1 (144), and one end of the other arm bar (147) is provided with a movable connecting piece 2 (146); the movable connecting piece 1 (144) is arranged on the inner side surface of the fixed height overflow weir (3), and the movable connecting piece 2 (146) is arranged on the inner side surface of the liquid drop plate (5); An open groove (145) is provided on the inner surface of the fixed-height overflow weir (3), and the open groove (145) corresponds to the position of the second movable connecting member (146); The flow range of the liquid on the tower plate (1) is expanded by the diameter difference between the cover cap (21) and the cover handle (22); the amount of liquid on the tower plate (1) is controlled by adjusting the combined height of the fixed-height overflow weir (3) and the dynamic-height overflow weir (4); a downcomer (5) in the opposite direction of displacement of the fixed-height overflow weir (3) controls the flow rate of the liquid entering the lower tower plate (1); and the liquid is guided by the fixed-height overflow weir (3) and the dynamic-height overflow weir (4) to flow to the next tower plate (1).

2. The esterification phase separator for preparing triacetin according to claim 1, characterized in that: A movable plate groove (31) is provided inside the fixed-height overflow weir (3), and the movable plate groove (31) matches the downcomer plate (5).

3. The esterification phase separator for preparing triacetin according to claim 1, characterized in that: The lower surface of the fixed plate (12) is evenly provided with docking grooves (121), and the docking grooves (121) match the riser pipe (13).

4. The esterification phase separator for preparing triacetin according to claim 1, characterized in that: The top end of the riser (13) is higher than the fixed-height overflow weir (3), and the upper end of the tube cavity (24) is located higher than the dynamic-height overflow weir (4).

5. The esterification phase separator for preparing triacetin according to claim 1, characterized in that: The air inlet groove (25) is a structure of four open grooves, with the groove openings distributed in a ring shape.

6. The esterification phase separator for preparing triacetin according to claim 1, characterized in that: The lifting assembly (142) comprises an outer ring (1421), a push block (1422), a fixed handle ring (1423) and an extrusion bevel groove (1424); the fixed handle ring (1423) is sleeved on the circumferential surface of the lift pipe (13); the extrusion bevel groove (1424) is provided on a side vertical surface of the fixed handle ring (1423); the outer ring (1421) is sleeved on the outside of the fixed handle ring (1423); the push block (1422) is installed on the inner surface of the outer ring (1421); and the push block (1422) is in contact with the extrusion bevel groove (1424).

7. An esterification phase separator for preparing triacetin according to claim 6, characterized in that: One end of the push block (1422) is provided with an inclined surface, which corresponds to the inner inclined surface of the extrusion inclined groove (1424).

Images