A DMM continuous esterification energy-saving reaction device

Abstract

The present invention relates to the field of chemical production technology, and specifically to a DMM continuous esterification energy-saving reaction device, a coupled reaction tower, a continuous reaction chamber is arranged in the middle of the coupled reaction tower, and horizontal partition plates are symmetrically arranged on the upper and lower sides of the interior of the continuous reaction chamber. The symmetrically arranged horizontal partition plates divide the interior of the continuous reaction chamber from top to bottom into a liquid phase input chamber, an interval heating chamber, and a gas phase input chamber. The liquid phase input chamber and the gas phase input chamber of the present invention are directly connected through multiple vertical esterification reaction tubes, so that the liquid and gas phases react efficiently in countercurrent on the catalyst surface, strengthening mass transfer and heat transfer, removing reaction water from the condensation separation chamber to break the equilibrium limit, and simultaneously completing product purification in the reboiling separation chamber. The entire process is carried out continuously, avoiding the repeated heating and cooling process of intermittent operation, significantly reducing energy consumption, and the fixed loading of acidic catalyst particles reduces repeated feeding loss, suppresses side reactions and improves product yield, realizing integrated operation of reaction and separation.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and in particular to a DMM continuous esterification energy-saving reaction device. Background Art

[0002] Dimethyl maleate, or DMM, is an important organic chemical raw material, widely used in the production of specialty resins, environmentally friendly plasticizers, pharmaceutical intermediates, and food additives. In recent years, with the rapid development of the biodegradable material polybutylene succinate, the demand for its key precursors, dimethyl succinate and dimethyl acetosuccinate, has surged. Industrially, DMM is primarily synthesized through the esterification reaction of maleic anhydride with methanol. This reaction is divided into two steps: maleic anhydride is first hydrolyzed to maleic acid, which is then esterified with methanol to produce DMM and water.

[0003] Currently, industrial DMM production mainly relies on intermittent esterification equipment. The reaction requires repeated heating and cooling of the temperature. The esterification stage requires insulation at 130 to 150 degrees Celsius, and the subsequent dehydration needs to be heated to greater than 180 degrees Celsius to break the azeotrope. This consumes a lot of energy, has low thermodynamic efficiency, and results in high overall production energy consumption. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose a DMM continuous esterification energy-saving reaction device to solve the problem that industrial DMM production mainly relies on intermittent esterification equipment, the reaction requires repeated heating and cooling, and the overall production energy consumption is high.

[0005] Based on the above objectives, the present invention provides a DMM continuous esterification energy-saving reaction device, comprising:

[0006] A coupled reaction tower is provided with a continuous reaction chamber in the middle thereof, and horizontal partition plates are symmetrically arranged on the upper and lower sides of the interior of the continuous reaction chamber. The symmetrically arranged horizontal partition plates divide the interior of the continuous reaction chamber from top to bottom into a liquid phase input chamber, an interval heating chamber, and a gas phase input chamber;

[0007] A plurality of esterification reaction tubes are evenly arranged vertically between the symmetrically arranged horizontal partition plates. The upper and lower ends of the esterification reaction tubes are respectively connected to the liquid phase input bin and the gas phase input bin. The interior of the esterification reaction tubes is filled with acidic catalyst particles.

[0008] A liquid distributor is provided in the middle of the liquid phase input bin, the outer side of the liquid distributor is connected to a liquid delivery pipe, and a metering delivery pump is provided in the middle of the liquid delivery pipe;

[0009] A gas distributor is provided in the middle of the gas phase input bin, and a gas delivery pipe is connected to the outer side of the gas distributor;

[0010] The condensation separation chamber is arranged above the continuous reaction chamber, and a condenser is arranged in the middle of the condensation separation chamber, and the condenser is connected to the top of the liquid phase input chamber;

[0011] The reboiling separation chamber is arranged below the continuous reaction chamber. The reboiling separation chamber is interconnected with the bottom of the liquid phase input chamber. A serpentine heating pipe is arranged inside the reboiling separation chamber, and the bottom of the reboiling separation chamber is connected to a product output pipe.

[0012] Furthermore, the lower end of the serpentine heating tube is connected to a heat transfer medium input tube, the upper end of the serpentine heating tube is communicated with the bottom end of the interval heating bin, the outer side of the top end of the interval heating bin is connected to a heat transfer medium output tube, the outer end of the gas delivery tube is connected to a spiral heating tube, the outer end of the spiral heating tube is connected to a methanol input tube, and the spiral heating tube is arranged around the interior of the interval heating bin.

[0013] Furthermore, the condenser includes an air collecting hood, which is located at the top of the liquid phase input bin. The top of the air collecting hood is connected to a condensation delivery pipe, and the top of the condensation delivery pipe is surrounded by a plurality of vertical condensation pipes. The vertical condensation pipes are interconnected with the liquid phase input bin through the condensation delivery pipe and the air collecting hood, and condensation fins are evenly arranged on the outside of the vertical condensation pipes.

[0014] Furthermore, the lower end of the vertical condenser is connected to a stratified storage tank, and the top and bottom of the side walls of the stratified storage tank are respectively connected to a reflux delivery pipe and a drain pipe, and the inner end of the reflux delivery pipe is vertically slidably connected to a telescopic delivery pipe, and an adjusting float is arranged around the outer side of the bottom opening of the telescopic delivery pipe, and a reflux delivery pump is arranged in the middle of the reflux delivery pipe, and the outer end of the reflux delivery pipe is connected to the methanol input pipe.

[0015] Furthermore, the liquid distributor includes a distribution plate, which is arranged parallel to the top of the esterification reaction tube opening. A plurality of distribution drip holes are evenly arranged in the middle of the distribution plate. The distribution drip holes are arranged corresponding to the top of the esterification reaction tube opening, and the distribution drip holes are located directly above the top of the esterification reaction tube opening.

[0016] Furthermore, a plurality of distribution nozzles are provided in the middle of the gas distributor, and the distribution nozzles are provided corresponding to the bottom opening of the esterification reaction tube, and the distribution nozzles are located directly below the bottom opening of the esterification reaction tube.

[0017] Furthermore, horizontal guide grooves are provided at the upper and lower openings of the esterification reaction tube, and a sliding sealing plate is provided on the inner side of the horizontal guide groove for horizontal sliding. The outer end of the sliding sealing plate is connected to a linkage push rod, and the side walls of the liquid phase input bin and the gas phase input bin are surrounded by multiple closed guide sleeves, and the linkage push rod is nested and slidably provided on the inner side of the closed guide sleeve, and a reset spring is provided in the middle of the linkage push rod.

[0018] Furthermore, an inclined feeding pipe and an inclined feeding pipe are respectively provided on the upper and lower sides of the side wall of the esterification reaction tube, the inner end of the inclined feeding pipe is inclined downward, and the outer end of the inclined feeding pipe is inclined downward, and a spacer wire mesh is provided inside the esterification reaction tube below the connection between the inclined feeding pipe and the esterification reaction tube, and the outer ends of the inclined feeding pipe and the inclined feeding pipe are respectively provided with a feeding opening and a feeding opening.

[0019] Furthermore, a rotating adjustment frame is nested and rotatably provided on the outer side of the continuous reaction chamber, and annular sealing plates are connected to the upper and lower ends of the rotating adjustment frame. The inner side wall of the annular sealing plate and the outer wall of the continuous reaction chamber are fitted together to remain closed, and a conveying opening is provided in the middle of the annular sealing plate. The rotating adjustment frame drives the annular sealing plate to rotate synchronously, so that the conveying opening in the middle of the upper and lower annular sealing plates and the loading opening or unloading opening overlap and open or stagger and close.

[0020] Furthermore, a linkage top block is connected to the outer side of the conveying opening, and the linkage top block and the linkage top rod are cooperated with each other. When the conveying opening and the loading opening or the unloading opening overlap and open, the linkage top block synchronously presses the linkage top rod to drive the sliding sealing plate to slide and close the upper and lower openings of the esterification reaction tube. When the conveying opening and the loading opening or the unloading opening overlap and close, the linkage top rod synchronously drives the sliding sealing plate to slide and reset to open the upper and lower openings of the esterification reaction tube.

[0021] Beneficial effects of the present invention: As can be seen from the above description, the present invention provides a DMM continuous esterification energy-saving reaction device, in which the liquid phase input bin and the gas phase input bin are directly connected through multiple vertical esterification reaction tubes, so that the liquid and gas phases react efficiently in countercurrent on the catalyst surface, enhancing mass transfer and heat transfer, the interval heating bin maintains the reaction temperature stable, the condensation separation bin promptly removes the reaction water to break the equilibrium limit, and the reboiling separation bin synchronously completes the product purification. The entire process is carried out continuously, avoiding the repeated heating and cooling process of intermittent operation, significantly reducing energy consumption, and the fixed loading of the acidic catalyst particles reduces repeated feeding losses, inhibits side reactions, and improves the product yield, thereby realizing the integrated operation of reaction and separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of the internal structure of a coupled reaction tower according to an embodiment of the present invention;

[0024] Figure 2 This is a front structural schematic diagram of a coupled reaction tower according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the back structure of a coupled reaction tower according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic structural diagram of a continuous reaction chamber according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the internal structure of a continuous reaction chamber according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic structural diagram of an esterification reaction tube according to an embodiment of the present invention;

[0029] Figure 7 This is a schematic structural diagram of a condensation separation bin according to an embodiment of the present invention;

[0030] Figure 8 Schematic diagram of the structure of the reboiler separation chamber according to an embodiment of the present invention.

[0031] The following are marked in the figure:

[0032] 1. Coupling reaction tower; 101. Continuous reaction chamber; 102. Horizontal partition plate; 103. Interval heating chamber; 104. Heat transfer medium output pipe; 2. Esterification reaction tube; 201. Horizontal guide groove; 202. Sliding sealing plate; 203. Linkage ejector pin; 204. Closed guide sleeve; 205. Return spring; 3. Liquid phase input chamber; 301. Liquid delivery pipe; 302. Metering delivery pump; 303. Liquid distributor; 304. Distribution plate; 305. Distribution drip hole; 4. Gas phase input chamber; 401. Gas delivery pipe; 402. Gas distributor; 403. Distribution nozzle; 404. Spiral heating tube; 405. Methanol input pipe; 5. Condensation separation Detaching chamber; 501, condenser; 502, gas collecting hood; 503, condensation conveying pipe; 504, vertical condensation pipe; 505, condensation fin; 6, stratified storage tank; 601, reflux conveying pipe; 602, reflux conveying pump; 603, telescopic conveying pipe; 604, adjusting float; 605, drain pipe; 7, reboiler separation chamber; 701, serpentine heating pipe; 702, heat transfer medium input pipe; 703, product output pipe; 8, inclined feeding pipe; 801, inclined discharging pipe; 802, spacer wire mesh; 803, feeding opening; 804, discharging opening; 9, rotating adjustment frame; 901, annular sealing plate; 902, conveying opening; 903, linkage top block. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0034] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0035] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, a DMM continuous esterification energy-saving reaction device comprises:

[0036] A coupled reaction tower 1 is provided with a continuous reaction chamber 101 in the middle thereof. Horizontal partition plates 102 are symmetrically arranged on the upper and lower sides of the interior of the continuous reaction chamber 101. The symmetrically arranged horizontal partition plates 102 divide the interior of the continuous reaction chamber 101 from top to bottom into a liquid phase input chamber 3, an interval heating chamber 103, and a gas phase input chamber 4.

[0037] A plurality of esterification reaction tubes 2 are evenly and vertically arranged between the symmetrically arranged horizontal partition plates 102. The upper and lower ends of the esterification reaction tubes 2 are respectively connected to the liquid phase input chamber 3 and the gas phase input chamber 4. The interior of the esterification reaction tubes 2 is filled with acidic catalyst particles.

[0038] A liquid distributor 303 is provided in the middle of the liquid phase input bin 3. The outer side of the liquid distributor 303 is connected to a liquid delivery pipe 301. A metering delivery pump 302 is provided in the middle of the liquid delivery pipe 301.

[0039] A gas distributor 402 is provided in the middle of the gas phase input chamber 4, and a gas delivery pipe 401 is connected to the outside of the gas distributor 402;

[0040] The condensation separation chamber 5 is arranged above the continuous reaction chamber 101. A condenser 501 is provided in the middle of the condensation separation chamber 5. The condenser 501 is connected to the top of the liquid phase input chamber 3.

[0041] The reboiling separation chamber 7 is arranged below the continuous reaction chamber 101. The reboiling separation chamber 7 is interconnected with the bottom of the liquid phase input chamber 3. A serpentine heating tube 701 is provided inside the reboiling separation chamber 7. The bottom of the reboiling separation chamber 7 is connected to a product output pipe 703.

[0042] In this embodiment, a continuous reaction chamber 101 is provided inside the coupled reaction tower 1 of the device, and two horizontal partition plates 102 are symmetrically provided above and below the continuous reaction chamber 101, which divide the entire reaction chamber from top to bottom into a liquid phase input chamber 3, an interval heating chamber 103 and a gas phase input chamber 4. The liquid phase input chamber 3 is located at the top and is used to receive and distribute the reaction liquid phase material. The gas phase input chamber 4 is located at the bottom and is used to introduce gas phase reactants and maintain system pressure balance. The interval heating chamber 103 is located in the middle and the reaction temperature is controlled by external heat supply. A plurality of esterification reaction tubes 2 are vertically and evenly arranged between the upper and lower horizontal partition plates 102. The upper end of each esterification reaction tube 2 is connected to the liquid phase input chamber 3, and the lower end is connected to the gas phase input chamber 4, forming a reaction flow. The esterification reaction tube 2 is filled with acidic catalyst particles for catalyzing the esterification reaction of maleic acid and methanol to produce DMM. A liquid distributor 303 is provided at the center of the liquid phase input chamber 3. The liquid distributor 303 is connected to the external raw material storage tank through a liquid delivery pipe 301, and is used to evenly distribute the reaction liquid prepared in proportion, such as a mixture of maleic acid and methanol, to each esterification reaction tube 2. A metering delivery pump 302 is installed in the middle section of the liquid delivery pipe 301 to achieve precise control of the feed amount. A gas distributor 402 is provided in the center of the gas phase input chamber 4, which is connected to an external gas source or a circulating gas system through a gas delivery pipe 401 to introduce methanol hydrate gas or recovered unreacted gas phase components into the reaction system to ensure The airflow of the reaction system is evenly distributed to promote full contact of the reactants. A condensation separation chamber 5 is provided above the continuous reaction chamber 101, and a condenser 501 is installed inside the condenser for cooling and condensing the gaseous products generated during the reaction, such as water vapor, excess methanol, etc., and refluxing them to the liquid input chamber 3 through the bottom of the condenser 501 to form a partial reflux, thereby improving the utilization rate of raw materials. A reboiling separation chamber 7 is provided below the continuous reaction chamber 101. The reboiling separation chamber 7 is connected to the bottom of the liquid input chamber 3, and a serpentine heating pipe 701 is provided inside the condenser for providing heat to vaporize the incompletely reacted liquid materials and enter the reaction system again, and to separate the high-boiling-point DMM to achieve efficient utilization of materials. The bottom of the reboiling separation chamber 7 is provided with a product input chamber. The outlet pipe 703 is used to continuously extract the DMM product after the reaction is completed. During production, the mixed liquid of the raw materials maleic anhydride and methanol enters the liquid phase input chamber 3 through the liquid delivery pipe 301 and the metering delivery pump 302 to control the flow rate. It is evenly dispersed by the liquid distributor 303 and flows into each esterification reaction tube 2. The methanol vapor enters the gas phase input chamber 4 through the gas distributor 402 through the gas delivery pipe 401 and then flows upward into the esterification reaction tube 2. The mixed liquid and methanol vapor contact the surface of the acidic catalyst particles filled in the esterification reaction tube 2 in countercurrent, and an esterification reaction occurs. The generated DMM liquid flows downward into the reboiling separation chamber 7, while the water vapor generated by the reaction and the unreacted methanol vapor rise into the condensation separation chamber 5 and are condensed into liquid by the condenser 501.The esterification product is heated in the reboiling separation chamber 7 by a serpentine heating tube 701 and then discharged from the product output pipe 703. The liquid phase input chamber 3 and the gas phase input chamber 4 are directly connected through multiple vertical esterification reaction tubes 2, allowing the liquid and gas phases to react efficiently in countercurrent on the catalyst surface, enhancing mass and heat transfer. The intermittent heating chamber 103 maintains a stable reaction temperature. The condensation separation chamber 5 promptly removes the reaction water to break the equilibrium limit. The reboiling separation chamber 7 simultaneously completes product purification. The entire process is carried out continuously, avoiding the repeated heating and cooling processes of intermittent operation, significantly reducing energy consumption. The fixed loading of acidic catalyst particles reduces repeated feeding losses, suppresses side reactions, and improves product yield, realizing an integrated operation of reaction and separation.

[0043] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 As shown, preferably, the lower end of the serpentine heating tube 701 of the device is connected to a heat transfer medium input pipe 702, and the heat transfer medium enters the serpentine heating tube 701 through the heat transfer medium input pipe 702 to heat and purify the esterification product in the reboiling separation chamber 7, and then the heat transfer medium flows into the bottom end of the interval heating chamber 103 and flows upward, and is finally discharged from the heat transfer medium output pipe 104 at the top of the interval heating chamber 103. The methanol liquid is passed into the spiral heating tube 404 through the methanol input pipe 405. The spiral heating tube 404 is arranged around the interior of the interval heating chamber 103, and the heat of the interval heating chamber 103 is used to preheat the methanol and convert it into steam. The generated methanol vapor is transported to the gas distributor 402 through the gas delivery pipe 401, and the serpentine heating tube 701 and the interval heating chamber 103 form a heat transfer medium circulation path to realize the heat energy sharing between the reboiling separation chamber 7 and the reaction chamber, and the heat transfer medium first heats the reboiling separation chamber 7 which requires a higher temperature, and then heats the reaction chamber which requires a lower temperature, so as to improve energy utilization. The spiral heating tube 404 is built into the interval heating chamber 103, and the residual heat of the reaction chamber is used to preheat the methanol raw material, reducing external energy input. The cascade utilization of the heat transfer medium reduces the total energy consumption of the system, and the integrated design of methanol gasification and reaction heating improves thermal efficiency.

[0044] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, preferably, the gas collecting hood 502 of the device is installed on the top of the liquid phase input bin 3, and is used to collect gaseous materials rising from the liquid phase input bin 3, such as water vapor, unreacted methanol vapor, etc. The top of the gas collecting hood 502 is connected to the condensation delivery pipe 503, and the condensation delivery pipe 503 delivers the gaseous materials to the interior of the vertical condensation pipe 504 above. The vertical condensation pipe 504 forms a connecting structure with the gas collecting hood 502 through the condensation delivery pipe 503, thereby realizing a circulating condensation reflux path for the gaseous materials. A plurality of condensation fins 505 are evenly arranged on the outside of the vertical condensation pipe 504. These condensation fins 505 can enhance the heat exchange efficiency, so that the high-temperature gaseous materials in the vertical condensation pipe 504 are rapidly cooled and condensed into liquid phase during the contact process with the external cooling medium, such as circulating cooling water or air. The condensed liquid is refluxed to the liquid phase input bin 3 through the condensation delivery pipe 503 to participate in the next round of reaction or be further separated and processed.

[0045] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 As shown, preferably, the outer end of the vertical condenser pipe 504 of the device is connected to a stratified storage tank 6 for collecting and preliminarily separating the condensed liquid products. The top of the side wall of the stratified storage tank 6 is connected to a reflux delivery pipe 601, and a drain pipe 605 is provided at the bottom, which are respectively used to recover the methanol component and discharge the condensed water. The inner end of the reflux delivery pipe 601 is vertically slidably connected to a telescopic delivery pipe 603. The bottom end opening of the telescopic delivery pipe 603 is set below the liquid level inside the stratified storage tank 6, and an adjusting float 604 is installed around the outside thereof for automatically adjusting the position of the suction port of the telescopic delivery pipe 603 according to the change of the liquid level in the tank, thereby realizing selective extraction. The upper layer of methanol-rich liquid components is taken, and a reflux delivery pump 602 is provided in the middle of the reflux delivery pipe 601 to provide delivery power. The outer end of the reflux delivery pump 602 is interconnected with the methanol input pipe 405 to re-deliver the separated methanol liquid to the reaction system for recycling, thereby achieving effective separation and selective reflux of the condensate. By adjusting the float 604 to float with the liquid level to control the liquid extraction depth of the telescopic delivery pipe 603, a high-purity methanol layer can be accurately obtained, and moisture and other impurities are prevented from entering the reaction system, thereby improving the reaction efficiency and product quality stability, while reducing the consumption of methanol raw materials, lowering production costs, and simplifying the subsequent wastewater treatment process.

[0046] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 As shown, preferably, the liquid distributor 303 of the device includes a distribution plate 304 arranged above the top opening of the esterification reaction tube 2, the distribution plate 304 is arranged horizontally, and a plurality of distribution drip holes 305 are evenly opened in the middle thereof. The position of each distribution drip hole 305 corresponds to the top opening of the esterification reaction tube 2 one by one and is located directly above it, and is used to evenly distribute the liquid raw material to each esterification reaction tube 2 to ensure the uniformity of the feed. A plurality of distribution nozzles 403 are arranged in the middle of the gas distributor 402, and these distribution nozzles 403 are connected to the bottom of the esterification reaction tube 2. The end openings correspond to each other and are located directly below each other, and are used to introduce gaseous raw materials, such as preheated methanol vapor, into the bottom of the esterification reaction tube 2 in a uniform manner, forming a reverse or synchronous flow contact with the liquid material, thereby improving the mass transfer efficiency between the reactants. The liquid distributor 303 and the gas distributor 402 respectively achieve uniform distribution of liquid and gaseous reactants before entering the esterification reaction tube 2, avoiding the reaction unevenness caused by local concentration differences, improving the catalyst utilization efficiency and the overall reaction conversion rate, and helping to maintain the stability of the system operation.

[0047] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 As shown, preferably, horizontal guide grooves 201 are provided at the upper and lower openings of the esterification reaction tube 2 of the device, and a horizontally slidable sliding sealing plate 202 is embedded in the inner side of the horizontal guide groove 201 for opening and closing the reaction tube opening at the corresponding end. The outer end of the sliding sealing plate 202 is connected to a linkage push rod 203, and the linkage push rod 203 is slidably arranged inside a plurality of closed guide sleeves 204 arranged around the side walls of the liquid phase input bin 3 and the gas phase input bin 4. A reset spring 205 is sheathed in the middle part of the linkage push rod 203, so that it can automatically reset to the initial position when there is no external force. By pushing the linkage push rod 203 to slide along the closed guide sleeve 204, the sliding sealing plate 202 can be driven to move in the horizontal guide groove 201, thereby realizing the controllable opening or closing of the upper and lower openings of the esterification reaction tube 2, thereby facilitating the adjustment of the number and distribution area of ​​the esterification reaction tubes 2 participating in the reaction according to actual operation requirements, realizing independent on-off control of each esterification reaction tube 2, and improving the system operation flexibility and maintenance convenience.

[0048] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, preferably, an inclined feeding pipe 8 and an inclined discharge pipe 801 are respectively provided on the upper and lower sides of the side wall of the esterification reaction tube 2 of the device, wherein the inner end of the inclined feeding pipe 8 is inclined downward and extends into the interior of the esterification reaction tube 2, and the outer end of the inclined discharge pipe 801 is also arranged to be inclined downward, for the introduction and export of catalyst particles. Inside the esterification reaction tube 2, a spacer wire mesh 802 is provided below the connection between the inclined discharge pipe 801 and the esterification reaction tube 2, and the spacer wire mesh 802 is used to prevent the catalyst particles from falling directly to the bottom of the esterification reaction tube 2, so that the catalyst particles are guided along the spacer wire mesh 802 into the inclined discharge pipe 801 under the action of gravity, so as to realize orderly transportation of the catalyst. The outer ends of the inclined feeding pipe 8 and the inclined discharge pipe 801 are respectively provided with a feeding opening 803 and a discharge opening 804, which are used for external loading or unloading of catalyst particles. A rotatable rotary adjustment frame 9 is nested on the outer side of the continuous reaction chamber 101. The upper and lower ends of the rotating adjustment frame 9 are respectively connected to annular sealing plates 901. The inner wall of the annular sealing plate 901 fits tightly against the outer wall of the continuous reaction chamber 101 to maintain a sealed state. A conveying opening 902 is provided on it. The rotating adjustment frame 9 drives the annular sealing plate 901 to rotate synchronously, so that the conveying openings 902 on the upper and lower annular sealing plates 901 can coincide with the corresponding loading opening 803 or unloading opening 804 to open the passage, or stagger and close the passage, thereby realizing the controllability and sealing of the catalyst loading and replacement process. Through the coordinated action of the rotating adjustment frame 9 and the annular sealing plate 901, independent catalyst loading and unloading operations can be performed on a single or multiple esterification reaction tubes 2 without affecting the overall operation of the reaction system, effectively avoiding problems such as material leakage and gas short circuit during the reaction process, improving the operational safety and maintenance convenience of the device, and ensuring the continuity and stability during the catalyst replacement process.

[0049] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, preferably, a linkage top block 903 is connected to the outer side of the device delivery opening 902, and the linkage top block 903 is arranged in cooperation with the linkage top rod 203 mentioned above, and is used to synchronously control the opening and closing state of the esterification reaction tube 2 during the catalyst loading and unloading process. When the rotary adjustment frame 9 drives the annular sealing plate 901 to rotate, so that the delivery opening 902 and the loading opening 803 or the unloading opening 804 overlap and open, the linkage top block 903 moves accordingly and presses the linkage top rod 203, pushing the sliding sealing plate 202 to slide along the horizontal guide groove 201, thereby closing the upper and lower openings of the esterification reaction tube 2, ensuring that the catalyst is loaded and unloaded. During the esterification reaction tube 2, the interior of the reaction tube remains sealed to prevent material leakage or gas short circuit. On the contrary, when the delivery opening 902 and the loading opening 803 or the unloading opening 804 are staggered and closed, the linkage push rod 203 drives the sliding sealing plate 202 to slide in the opposite direction under the action of the reset spring 205, so that the upper and lower end openings of the esterification reaction tube 2 are reopened, and the normal reaction flow path is restored, realizing the linkage control between the catalyst loading and unloading operation and the opening and closing state of the reaction tube, which not only improves the safety and controllability of the operation, but also effectively guarantees the sealing performance and operation stability of the reaction system, which is conducive to the continuous and automatic operation of the device.

[0050] During use, a mixed liquid of raw materials maleic anhydride and methanol enters the liquid phase input chamber 3 through the liquid delivery pipe 301 and the metering delivery pump 302 under flow control, and then flows into each esterification reaction tube 2 after being evenly dispersed by the liquid distributor 303. The methanol vapor enters the gas phase input chamber 4 through the gas delivery pipe 401 and the gas distributor 402, and then flows upward into the esterification reaction tube 2. The mixed liquid and the methanol vapor contact the surface of the acidic catalyst particles filled in the esterification reaction tube 2 in countercurrent, and an esterification reaction occurs. The generated DMM liquid flows downward into the reboiling separation chamber 7, while the water vapor and unreacted methanol vapor generated by the reaction rise into the condensation separation chamber 5 and are condensed into liquid through the condenser 501. The esterification product is heated in the reboiling separation chamber 7 by the serpentine heating tube 701 and discharged from the product output pipe 703.

[0051] The DMM continuous esterification energy-saving reaction device provided by the present invention has a liquid phase input chamber 3 and a gas phase input chamber 4 directly connected through multiple vertical esterification reaction tubes 2, so that the liquid and gas phases react efficiently in countercurrent on the catalyst surface, enhancing mass transfer and heat transfer. The interval heating chamber 103 maintains a stable reaction temperature. The condensation separation chamber 5 promptly removes the reaction water to break the equilibrium limit. The reboiling separation chamber 7 synchronously completes product purification. The entire process is carried out continuously, avoiding the repeated heating and cooling process of intermittent operation, significantly reducing energy consumption. The fixed loading of acidic catalyst particles reduces repeated feeding losses, suppresses side reactions, and improves product yield, realizing integrated operation of reaction and separation.

[0052] Those skilled in the art will understand that the discussion of any of the above embodiments is merely illustrative and is not intended to limit the scope of the present invention to these examples. Within the spirit and principles of the present invention, the technical features of the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and many other variations exist for the various aspects of the present invention described above, which are not provided in detail for the sake of clarity. Any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A DMM continuous esterification energy-saving reaction device, characterized in that: include: A coupled reaction tower (1) is provided with a continuous reaction chamber (101) in the middle thereof, and horizontal partition plates (102) are symmetrically provided on upper and lower sides of the interior of the continuous reaction chamber (101). The interior of the continuous reaction chamber (101) is sequentially divided from top to bottom into a liquid phase input chamber (3), an interval heating chamber (103), and a gas phase input chamber (4) by the symmetrically provided horizontal partition plates (102); A plurality of esterification reaction tubes (2) are evenly and vertically arranged between symmetrically arranged horizontal partition plates (102), the upper and lower ends of the esterification reaction tubes (2) being respectively connected to the liquid phase input bin (3) and the gas phase input bin (4), and the interior of the esterification reaction tubes (2) is filled with acidic catalyst particles; A liquid distributor (303) is provided in the middle of the liquid phase input bin (3), a liquid delivery pipe (301) is connected to the outside of the liquid distributor (303), and a metering delivery pump (302) is provided in the middle of the liquid delivery pipe (301); A gas distributor (402) is provided in the middle of the gas phase input chamber (4), and a gas delivery pipe (401) is connected to the outside of the gas distributor (402); A condensation separation chamber (5) is provided above the continuous reaction chamber (101), a condenser (501) is provided in the middle of the condensation separation chamber (5), and the condenser (501) is communicated with the top of the liquid phase input chamber (3); A reboiling separation chamber (7) is provided below the continuous reaction chamber (101), the reboiling separation chamber (7) is in communication with the bottom of the liquid phase input chamber (3), a serpentine heating pipe (701) is provided inside the reboiling separation chamber (7), and a product output pipe (703) is connected to the bottom of the reboiling separation chamber (7); The esterification reaction tube (2) is provided with a horizontal guide groove (201) at both upper and lower openings, a sliding sealing plate (202) is provided on the inner side of the horizontal guide groove (201) for horizontal sliding engagement, and a linkage push rod (203) is provided at the outer end of the sliding sealing plate (202). The side walls of the liquid phase input chamber (3) and the gas phase input chamber (4) are both provided with a plurality of closed guide sleeves (204) around them, and the linkage push rod (203) is nested and slidably provided on the inner side of the closed guide sleeve (204), and a return spring (205) is provided in the middle of the linkage push rod (203); An inclined feeding pipe (8) and an inclined discharging pipe (801) are respectively provided on the upper and lower sides of the side wall of the esterification reaction tube (2); and a feeding opening (803) and a discharging opening (804) are respectively provided at the outer ends of the inclined feeding pipe (8) and the inclined discharging pipe (801); A rotating adjustment frame (9) is nested and rotatably provided on the outer side of the continuous reaction chamber (101), and an annular sealing plate (901) is connected to the upper and lower ends of the rotating adjustment frame (9). The inner side wall of the annular sealing plate (901) and the outer wall of the continuous reaction chamber (101) are fitted together to maintain a closed state. A conveying opening (902) is provided in the middle of the annular sealing plate (901). The rotating adjustment frame (9) drives the annular sealing plate (901) to rotate synchronously, so that the conveying opening (902) in the middle of the upper and lower annular sealing plates (901) and the loading opening (803) or the unloading opening (804) overlap and open, or overlap and close.

2. The DMM continuous esterification energy-saving reaction device according to claim 1, characterized in that: The lower end of the serpentine heating tube (701) is connected to a heat transfer medium input tube (702), the upper end of the serpentine heating tube (701) is communicated with the bottom end of the interval heating chamber (103), the top outer side of the interval heating chamber (103) is connected to a heat transfer medium output tube (104), the outer end of the gas delivery tube (401) is connected to a spiral heating tube (404), the outer end of the spiral heating tube (404) is connected to a methanol input tube (405), and the spiral heating tube (404) is arranged around the interior of the interval heating chamber (103).

3. The DMM continuous esterification energy-saving reaction device according to claim 2, characterized in that: The condenser (501) includes an air collecting hood (502), which is located at the top of the liquid phase input bin (3). The top of the air collecting hood (502) is connected to a condensation delivery pipe (503), and the top of the condensation delivery pipe (503) is surrounded by a plurality of vertical condensation pipes (504). The vertical condensation pipes (504) are interconnected with the liquid phase input bin (3) through the condensation delivery pipe (503) and the air collecting hood (502), and condensation fins (505) are evenly arranged on the outside of the vertical condensation pipes (504).

4. The DMM continuous esterification energy-saving reaction device according to claim 3, characterized in that: The lower end of the vertical condensing pipe (504) is connected to a stratified storage tank (6), and the top and bottom of the side wall of the stratified storage tank (6) are respectively connected to a reflux delivery pipe (601) and a drain pipe (605). The inner end of the reflux delivery pipe (601) is vertically slidably connected to a telescopic delivery pipe (603), and an adjusting float (604) is arranged around the outer side of the bottom opening of the telescopic delivery pipe (603). A reflux delivery pump (602) is arranged in the middle of the reflux delivery pipe (601), and the outer end of the reflux delivery pipe (601) is communicated with the methanol input pipe (405).

5. The DMM continuous esterification energy-saving reaction device according to claim 1, characterized in that: The liquid distributor (303) includes a distribution plate (304), which is arranged parallel to the top of the opening of the esterification reaction tube (2). A plurality of distribution drip holes (305) are evenly arranged in the middle of the distribution plate (304). The distribution drip holes (305) are arranged corresponding to the top of the opening of the esterification reaction tube (2). The distribution drip holes (305) are located directly above the top of the opening of the esterification reaction tube (2).

6. The DMM continuous esterification energy-saving reaction device according to claim 1, characterized in that: A plurality of distribution nozzles (403) are provided in the middle of the gas distributor (402), and the distribution nozzles (403) are provided corresponding to the bottom opening of the esterification reaction tube (2), and the distribution nozzles (403) are located directly below the bottom opening of the esterification reaction tube (2).

7. The DMM continuous esterification energy-saving reaction device according to claim 1, characterized in that: The inner end of the inclined feeding pipe (8) is arranged to be tilted downward, the outer end of the inclined discharging pipe (801) is arranged to be tilted downward, and a spacer wire mesh (802) is arranged inside the esterification reaction tube (2) below the connection between the inclined discharging pipe (801) and the esterification reaction tube (2).

8. The DMM continuous esterification energy-saving reaction device according to claim 7, characterized in that: The outer side of the delivery opening (902) is connected to a linkage top block (903), and the linkage top block (903) and the linkage top rod (203) are arranged in cooperation with each other. When the delivery opening (902) and the loading opening (803) or the unloading opening (804) overlap and open, the linkage top block (903) synchronously presses the linkage top rod (203) to drive the sliding sealing plate (202) to slide and close the upper and lower openings of the esterification reaction tube (2). When the delivery opening (902) and the loading opening (803) or the unloading opening (804) overlap and close, the linkage top rod (203) synchronously drives the sliding sealing plate (202) to slide and reset so that the upper and lower openings of the esterification reaction tube (2) are opened.

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