Methylamine rectification equipment, separation and purification assembly and purification process

Abstract

The invention discloses methylamine rectification equipment, a separation and purification assembly and a purification process, and relates to the technical field of methylamine processing.The methylamine rectification equipment comprises a tower body, a skirt is arranged at the bottom of the tower body, a manhole is formed in the side face of the skirt, a drain pipe is arranged at the bottom of the tower body, a ventilation hole is formed in the side face of the skirt, and a steam ingress pipe is arranged at the bottom of the side face of the tower body; a liquid inlet pipe is arranged on the side face of the tower body, a backflow pipe and a tower body top hanging column are arranged on the two sides of the top of the side face of the tower body respectively, a steam guide-out pipe is arranged at the top end of the tower body, a gas-liquid separator is arranged on the top side of the interior of the tower body, and tower plate assemblies are vertically arranged in the tower body in a staggered mode. Moreover, when the tower plate leaks liquid, monitoring is carried out in time, process parameters are adjusted in time, in addition, the flow speed of liquid on the tower plate can be adjusted conveniently according to production requirements, and blockage clearing can be intervened in time conveniently when the tower plate is blocked.

Description

Technical Field

[0001] The invention relates to the technical field of methylamine processing, in particular to methylamine distillation equipment, separation and purification components, and a purification process. Background Art

[0002] Methylamine is an important class of organic compounds, mainly including monomethylamine, dimethylamine and trimethylamine. Methylamine distillation is a key link in the methylamine production process, which aims to separate the mixture after the methylamine synthesis reaction into high-purity monomethylamine, dimethylamine, trimethylamine and other products. In the prior art, methylamine distillation equipment usually includes a deamination tower (Tower I), an extraction tower (Tower II), a dehydration tower (Tower III), a separation tower (Tower IV) and a methanol recovery tower (Tower V). The dehydration tower is a crucial link in the methylamine distillation process, which is mainly used to separate water in the feed from organic components such as monomethylamine and dimethylamine.

[0003] Chinese patent application number 2017207591622 discloses a plate-type distillation tower, comprising a tower body and a plurality of plates, wherein the plates divide the tower body into a plurality of distillation chambers, and a pressure regulating mechanism is arranged between the distillation chambers, wherein the pressure regulating mechanism comprises a transverse tube and a branch tube; one end of the transverse tube is connected to the distillation chamber, and one end of the branch tube is connected to another distillation chamber; the other end of the branch tube is connected to the transverse tube; a slider and an elastic member are also arranged in the transverse tube, wherein one end of the elastic member is fixed to one end of the transverse tube away from the distillation chamber, and the other end is fixedly connected to the slider; in the initial state, the elastic member is in a relaxed state, the slider is located at the connection between the branch tube and the transverse tube, and the branch tube and the transverse tube are not connected.

[0004] However, in actual use, the above-mentioned prior art cannot adjust the tower plate spacing as needed. If the tower plate spacing is too small, liquid flooding will occur when the gas-liquid flow rate in the tower exceeds the carrying capacity of the tower plate, resulting in poor quality of the top tower product. In addition, when the gas-liquid flow rate in the tower is lower than the lower limit of the tower plate's carrying capacity, liquid leakage will occur, causing the liquid to flow directly from the tower plate openings, resulting in insufficient gas-liquid contact and reduced mass transfer and heat transfer efficiency.

[0005] In addition, in the dehydration process using a plate distillation tower, the liquid on the plate flows into the downcomer too quickly, resulting in a short and insufficient contact time between the steam and the liquid, thereby reducing the mass transfer efficiency. In addition, the raw materials or reaction products in the methylamine production process contain impurities, polymers or solid particles, which are easily accumulated on the plate, causing the plate to be blocked, thereby making the gas-liquid contact uneven and the mass and heat transfer effects worse. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the existing defects and provide a methylamine distillation equipment and a separation and purification component, a purification process, so as to adjust the distance between the tower plates to reduce the risk of flooding, and timely monitor and adjust the process parameters when the tower plates leak. In addition, it is convenient to adjust the flow rate of the liquid on the tower plates according to production needs, and to intervene and clear the blockage in time when the tower plates are blocked.

[0007] To achieve the above object, the present invention provides the following technical solutions: On the one hand, the present invention provides a methylamine distillation device, comprising a tower body, wherein a skirt is provided at the bottom of the tower body, a manhole is provided on the side of the skirt, a liquid discharge pipe is provided at the bottom of the tower body, a ventilation hole is provided on the side of the skirt, a steam introduction pipe is provided at the bottom of the side of the tower body, a liquid inlet pipe is provided on the side of the tower body, a reflux pipe and a tower body top suspension column are provided on both sides of the top of the side of the tower body, a steam outlet pipe is provided at the top of the tower body, a gas-liquid separator is provided on the top side of the tower body, and a tower plate assembly is vertically staggered inside the tower body; The tower plate assembly includes a tower plate, which is slidably matched with the inner wall of the tower body. Air holes are evenly opened in the middle of the tower plate. An overflow weir is provided on one side of the tower plate, and a downcomer is penetrated on the other side of the tower plate. The downcomer is an arc-shaped structure, and two adjacent tower plates are arranged alternately.

[0008] On the other hand, the present invention also provides a methylamine separation and purification component, which is applicable to the methylamine distillation equipment as described above, comprising a tray assembly, and also comprising an adjustment assembly evenly arranged on the side of the tower body from top to bottom, a detection assembly arranged at the bottom of the tray assembly, and auxiliary assemblies staggered on both sides of the inner wall of the tower body, wherein the auxiliary assemblies are located on the upper side of the tray assembly; The adjustment assembly comprises a guide rail seat evenly distributed vertically, the guide rail seat is embedded in the side of the tower body, a sealing slide seat is slidably connected inside the guide rail seat, and a screw rod is vertically rotatably connected to the middle of the guide rail seat; The detection assembly includes a hollow rod and a sliding rod which are arranged obliquely. The hollow rod is slidably sleeved on the outside of the middle sliding rod. The end of the hollow rod is hinged to the bottom surface of the tower plate through a hinge seat. The outer end of each sliding rod is hinged to a collecting cylinder. The top surface of the sliding rod is provided with an elastic member through a fixing rod. The auxiliary component includes cover plates staggered in the vertical direction and a telescopic part arranged horizontally, a support rod is provided at the bottom of the telescopic end of the telescopic part through a mounting seat, and the support rod is fixedly connected to the top of the cover plate.

[0009] Preferably, the guide rail seat corresponds to the position of the tower tray, the sealing slide seat is an arc-shaped structure, the arc-shaped surface of the sealing slide seat is fixedly connected to the side of the tower tray, and a liquid level meter is provided on the tower tray.

[0010] Preferably, the screw is threadedly connected to the sealing slide seat, an adjusting motor is provided at the bottom of the guide rail seat, and an output shaft of the adjusting motor is fixedly connected to the end of the screw.

[0011] Preferably, the hollow rods are distributed in a circular array on the bottom surface of the tower plate, the upper surfaces of the sliding rods and the hollow rods are correspondingly provided with grooves, and a spring is provided between the end of the sliding rod and the inner end surface of the hollow rod.

[0012] Preferably, an elastic block is provided at the bottom of the collecting cylinder, a liquid level sensor is provided inside the collecting cylinder, and a drain valve is provided at one side of the bottom of the collecting cylinder.

[0013] Preferably, the cover plate is located above the downcomer, the cover plate is an arc-shaped structure, the cover plate matches the internal cross-sectional dimensions of the downcomer, a cleaning portion is provided on the bottom surface of the cover plate, and the fixed end of the telescopic portion is provided on the inner wall of the tower body.

[0014] In addition, the present invention also provides a methylamine purification process, wherein the purification process utilizes the separation and purification assembly as described above to achieve purification of methylamine during the production process, and comprises the following steps: S1. After preheating the material from the extraction tower, the material is fed through the liquid inlet pipe located between the rectifying section and the stripping section, and the incoming liquid passes through each tray assembly in an interlaced manner from top to bottom; S2, the reboiler at the bottom of the tower body inputs steam into the tower body through the steam inlet pipe to heat the incoming liquid, and the steam flow rate is accurately controlled by adjusting the opening of the steam inlet valve to control the vaporization amount of the tower bottom liquid; S3, the vaporized steam carries energy and mass from bottom to top through the air holes on the tray and enters the upper tray assembly. On each tray assembly, the rising steam fully contacts the liquid overflowing from the upper tray assembly. S4. The volatile components of methylamine in the steam diffuse into the liquid phase, while the non-volatile components of water in the liquid phase diffuse into the gas phase. During multiple gas-liquid contacts, the light components of methylamine gradually accumulate at the top of the tower and are discharged through the gas-liquid separator and the steam outlet pipe, while the heavy components such as water move to the bottom of the tower to achieve preliminary separation. S5. When flooding occurs, use the adjustment component to adjust the distance between the tower plate components to reduce the risk of flooding. When the pores are blocked, clear the pores by cooperating with the adjustment component and the detection component. S6, the steam at the top of the tower body enters the condenser and condenses into liquid and flows into the external reflux tank. A part of the liquid returns to the top of the tower body through the reflux pipe as reflux liquid and flows down along the tower plate assembly, continuing to transfer mass and heat with the rising steam for further separation, and the other part is extracted as the product; S7. The methylamine product taken from the top of the tower is transported to the product storage tank through a pipeline and an online mass analyzer is set to monitor the indicators of methylamine in real time. The mixture of monomethylamine and dimethylamine taken from the top of the tower is sent to a separation tower for further separation, and the liquid at the bottom of the tower is discharged through a drain pipe.

[0015] Compared with the prior art, the present invention has the following advantages: 1. When liquid flooding occurs in the tower body, the present invention starts the regulating motor at the liquid inlet to move the tower tray upward, reduce the opening at the top of the downcomer, limit the amount of liquid flowing from the upper tower tray to the lower tower tray per unit time, and alleviate the liquid flooding. When the liquid flooding is still not alleviated, start the other regulating motors at the bottom to increase the distance between the lower tower trays to provide a larger gas-liquid separation space, thereby further alleviating the liquid flooding phenomenon.

[0016] 2. When cleaning the air holes, the present invention uses an adjusting motor to reduce the distance between the tower plates, and then uses the adjusting motor to make the tower plates reciprocate up and down. At the same time, the hollow rod, the sliding rod and the collecting tube swing back and forth up and down. At this time, the tower plates move up and down quickly to make the elastic parts and the elastic blocks collide with the bottom and top of the tower plates in a cycle, respectively, causing the tower plates to vibrate, and the impurities attached to the air holes are shaken off, thereby cleaning the air holes.

[0017] 3. When cleaning the surface of the tower plate, the present invention utilizes the driving force of the telescopic part to make the cover plate move horizontally to a position corresponding to the edge pores, and then uses the adjusting component to make the top surface of the tower plate collide with the cleaning part of the bottom surface of the cover plate, and utilizes the telescopic part to make the cover plate and the cleaning part move back and forth horizontally to achieve the cleaning of the tower plate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention; Figure 3 For the present invention Figure 2 The enlarged structural diagram at A in the middle; Figure 4 This is a schematic diagram of the structure of the separation and purification component of the present invention; Figure 5 This is a schematic structural diagram of the separation and purification component of the present invention from another angle.

[0019] In the figure: 1. tower body; 101. skirt; 102. manhole; 103. drain pipe; 104. ventilation hole; 105. steam inlet pipe; 106. liquid inlet pipe; 107. reflux pipe; 108. steam outlet pipe; 109. top hanging column; 110. gas-liquid separator; 2. tower plate assembly; 201. tower plate; 202. air hole; 203. overflow weir; 204. downcomer; 3. regulating assembly; 3 01. Guide rail seat; 302. Screw rod; 303. Sealing slide seat; 304. Adjusting motor; 4. Detection assembly; 401. Articulated seat; 402. Hollow rod; 403. Slide rod; 404. Spring; 405. Collecting cylinder; 406. Elastic block; 407. Fixed rod; 408. Elastic part; 5. Auxiliary assembly; 501. Cover plate; 502. Telescopic part; 503. Mounting seat; 504. Support rod. DETAILED DESCRIPTION

[0020] 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.

[0021] Embodiment 1 See also Figure 1-5 The present embodiment discloses a methylamine distillation device, comprising a tower body 1, a skirt 101 is provided at the bottom of the tower body 1, a manhole 102 is provided on the side of the skirt 101, a liquid discharge pipe 103 is provided at the bottom of the tower body 1, a ventilation hole 104 is provided on the side of the skirt 101, a steam introduction pipe 105 is provided at the bottom of the side of the tower body 1, a liquid inlet pipe 106 is provided on the side of the tower body 1, a reflux pipe 107 and a tower body 1 top suspension column 109 are respectively provided on both sides of the top of the side of the tower body 1, a steam outlet pipe 108 is provided on the top of the tower body 1, a gas-liquid separator 110 is provided on the internal top side of the tower body 1, and a tower plate assembly 2 is vertically staggered inside the tower body 1.

[0022] The tower plate assembly 2 includes a tower plate 201, which is slidably matched with the inner wall of the tower body 1. Air holes 202 are evenly opened in the middle of the tower plate 201. An overflow weir 203 is provided on one side of the tower plate 201. A downcomer 204 is penetrated on the other side of the tower plate 201. The downcomer 204 is an arc-shaped structure. Two adjacent tower plates 201 are arranged alternately.

[0023] When in use, the material from the extraction tower is transported to the feeding system of the tower body 1. A flow meter and a regulating valve are installed on the conveying pipeline to accurately control the feed flow rate to ensure the stability of the distillation tower feed. Before entering the tower body 1, the material is preheated by a preheater. The preheater is preferably a shell-and-tube heat exchanger to make the material close to the temperature of the liquid inlet of the tower body 1 to ensure that the raw material quickly reaches a gas-liquid equilibrium state after entering the tower, while avoiding premature vaporization of part of the methylamine due to excessively high temperature, which affects the distillation effect.

[0024] Secondly, the liquid inlet pipe 106 located between the rectifying section and the stripping section is selected as the liquid inlet to introduce the material into the tower body 1. The material first falls on the topmost tower plate 201 and flows horizontally to the downcomer 204 on the other side, then falls on the tower plate 201 of the next layer through the downcomer 204 and then flows horizontally to the downcomer 204. The material flows on each tower plate 201 from top to bottom in an alternating manner. At the same time, the tower bottom reboiler injects steam into the bottom of the tower body 1 through the steam introduction pipe 105. The steam flow rate is accurately controlled by adjusting the opening of the steam inlet valve. The introduced steam passes through each tower plate 201 in turn from bottom to top through the pores 202. The liquid When the bulk material flows horizontally on the tray 201, it contacts the rising steam, and the liquid part of the material is vaporized to generate rising steam. The vaporized steam passes through the air holes 202 from bottom to top and enters the upper tray. On each tray 201, the rising steam fully contacts the liquid on the upper tray 201. According to the gas-liquid equilibrium principle, volatile components such as methylamine in the steam diffuse into the liquid phase because their concentration in the gas phase is higher than that in the liquid phase; while non-volatile components such as water in the liquid phase diffuse into the gas phase. During multiple gas-liquid contacts, light components such as methylamine gradually accumulate at the top of the tower, and heavy components such as water move to the bottom of the tower, thereby achieving preliminary separation.

[0025] The steam at the top of the tower enters the external condenser and is condensed into liquid. The condensed liquid flows into the external reflux tank. The flow rate of the reflux pump is adjusted by the reflux ratio controller. Part of the liquid returns to the top of the tower body 1 as reflux liquid, and the other part is produced as the top product. As the gas-liquid mass transfer process proceeds, water as a heavy component continuously flows to the bottom of the tower body 1 under the action of gravity. At the bottom of the tower, water is gradually enriched and the concentration continues to increase. By controlling the bottom temperature and the plate efficiency, the water can be effectively separated at the bottom of the tower.

[0026] When the methylamine product extracted from the top of the tower is transported to the product through a pipeline, an online mass analyzer is used to monitor the purity, moisture content and other indicators of the methylamine in real time, and the liquid at the bottom of the tower is discharged through the drain pipe 103.

[0027] Embodiment 2 This embodiment discloses a methylamine separation and purification component, including a tower plate component 2. The separation and purification component also includes an adjustment component 3 evenly arranged on the side of the tower body 1 from top to bottom and an auxiliary component 5 staggered on both sides of the inner wall of the tower body 1. The auxiliary component 5 is located on the upper side of the tower plate component 2.

[0028] The adjustment component 3 includes a guide rail seat 301 evenly distributed vertically, the guide rail seat 301 corresponds to the position of the tower plate 201, the guide rail seat 301 is embedded in the side of the tower body 1, and a sealing slide 303 is slidably connected in the guide rail seat 301. The sealing slide 303 is an arc-shaped structure, and the arc surface of the sealing slide 303 is fixedly connected to the side of the tower plate 201. The inner arc surface of the sealing slide 303 is cocircular with the side of the guide rail seat 301 and the inner wall of the tower body 1, which ensures the sealing effect and prevents air leakage and leakage. Liquid, a screw rod 302 is vertically rotatably connected in the middle of the guide rail seat 301, and the screw rod 302 is threadedly connected to the sealing slide seat 303. An adjusting motor 304 is provided at the bottom of the guide rail seat 301, and the output shaft of the adjusting motor 304 is fixedly connected to the end of the screw rod 302. Specifically, the screw rod 302 is driven to rotate forward and reversely by the forward and reverse rotation of the adjusting motor 304, and the tower plate 201 can be driven to move up and down through the sealing slide seat 303 to realize the adjustment of the distance between each tower plate 201.

[0029] A liquid level meter is provided on the tower tray 201, and the liquid level meter is used to detect the liquid level on the tower tray 201 to determine whether liquid flooding occurs.

[0030] The auxiliary component 5 includes a cover plate 501 staggered in the vertical direction and a telescopic part 502 arranged horizontally. The cover plate 501 is located above the downcomer 204. The fixed end of the telescopic part 502 is arranged on the inner wall of the tower body 1. The telescopic part 502 is an electric telescopic mechanism, and can also be a hydraulic telescopic mechanism. A support rod 504 is provided at the bottom of the telescopic end of the telescopic part 502 through a mounting seat 503. The support rod 504 is fixedly connected to the top of the cover plate 501. By using the adjustment component 3 to drive the tower plate 201 to move upward, the distance between the top of the downcomer 204 and the cover plate 501 is adjusted, thereby realizing the adjustment of the opening size of the downcomer 204.

[0031] It should be noted that, when adjusting the size of the top opening of the downcomer 204, in order to prevent the distance between the tower trays 201 from changing, the adjustment components 3 should be made to drive the tower trays 201 to move synchronously.

[0032] During use, when the liquid level meter detects that the liquid level on the corresponding tower tray 201 is greater than the liquid level threshold set by the liquid level meter, it means that liquid has accumulated on the lower tower tray 201, and it is actively judged that liquid flooding has occurred. At this time, the regulating motor 304 close to the liquid inlet is started first, and the tower tray 201 at the liquid inlet moves upward through the cooperation of the screw 302 and the sealing slide 303, so that the top of the downcomer 204 is close to the cover plate 501, thereby reducing the top opening of the downcomer 204 at the liquid inlet, limiting the amount of liquid flowing from the upper tower tray 201 to the lower tower tray 201 per unit time, reducing the thickness of the liquid layer on the lower tower tray 201, slowing down the flow rate of the liquid on the lower tower tray 201, and prolonging the residence time of the liquid on the tower tray 201, so as to make the gas-liquid contact more orderly and alleviate liquid flooding.

[0033] When the liquid level meter detects that the flooding phenomenon has not been alleviated, the remaining regulating motors 304 at the bottom are synchronously started to increase the distance between the lower tower plates 201 and the spacing between the tower plates 201, thereby providing a larger gas-liquid separation space and further alleviating the flooding phenomenon.

[0034] However, during the separation and purification process, when the gas-liquid flow rate in the tower is lower than the lower limit of the carrying capacity of the tray assembly 2, the liquid on the tray 201 does not fully contact the gas phase and directly flows down from the tray holes, resulting in liquid leakage, which cannot be monitored in time and reduces the dehydration effect. In order to solve the above problems, the following improvements are made: The separation and purification component also includes a detection component 4 arranged at the bottom of the tower plate component 2, and the detection component 4 includes an inclined hollow rod 402 and a sliding rod 403. The hollow rod 402 is distributed in a circular array on the bottom surface of the tower plate 201, and the hollow rod 402 is slidably sleeved on the outside of the sliding rod 403. The end of the hollow rod 402 is hinged to the bottom surface of the tower plate 201 through a hinge seat 401. The upper surfaces of the sliding rod 403 and the hollow rod 402 are respectively provided with grooves, and the grooves are used to guide the flow direction of the liquid. A spring 404 is provided between the end of the sliding rod 403 and the internal end surface of the hollow rod 402. A collecting tube 405 is hinged to the outer end of each sliding rod 403. A liquid level sensor is provided inside the collecting tube 405. A drain valve is provided on one side of the bottom of the collecting tube 405, and the drain valve is used to discharge the liquid in the collecting tube 405.

[0035] During use, when liquid leakage occurs on the tower plate 201, the leaked liquid will fall into the grooves on the upper side of the sliding rod 403 and the hollow rod 402, and flow along the grooves to the collecting tube 405. When the liquid level sensor inside the collecting tube 405 detects that liquid has entered and the liquid level has risen rapidly, it is actively determined that there is leakage on the tower plate 201, and at the same time, an abnormal signal is sent to the external control terminal to remind the staff to adjust the process parameters.

[0036] It should be noted that in order to improve the accuracy and timeliness of detection, by increasing the density of the circular array of sliding rods 403 and hollow rods 402, the liquid leaked from the tower plate 201 can more easily fall into the grooves on the sliding rods 403 and hollow rods 402, thereby making the detection more timely and accurate.

[0037] In addition, after long-term use, the pores 202 on the tray 201 will be blocked by impurities in the material, reducing the mass transfer and heat transfer efficiency. In order to solve the above problem, the following improvements are made: The top surface of the slide bar 403 is provided with an elastic member 408 through a fixing rod 407, and the bottom of the collecting tube 405 is provided with an elastic block 406. The elastic member 408 and the elastic block 406 are preferably made of rubber, and the collecting tube 405 has a certain weight.

[0038] In order to prevent the air holes 202 from being blocked after long-term use, the tower plate 201 is cleaned after each use to clean the air holes 202. During cleaning, the adjusting motor 304 is started to make the tower plates 201 close to each other and reduce the distance between the tower plates 201. Then, the adjusting motors 304 are rotated forward and reversely, and the sealing slide 303 and the tower plates 201 are driven to reciprocate rapidly up and down through the forward and reverse rotation of the screw rod 302. At the same time, the hollow rods 402 and the slide rods 403 are swung back and forth rapidly up and down. When the tower plate 201 moves upward rapidly, under the action of the deadweight of the collecting tube 405, the tower plate 201 and the collecting tube 405 will first move away from each other, and the spring 404 will be stretched. When the tower plate 201 moves downward rapidly, under the elastic action of the spring 404, the tower plate 201 and the collecting tube 405 are close to each other. The elastic member 408 hits the bottom of the tower plate 201, thereby causing the tower plate 201 to vibrate. At the same time, during this process, under the action of the elasticity of the elastic member 408 itself, the elastic member 408 will quickly rebound downward after hitting the bottom of the tower plate 201, and the collecting tube 405 will quickly move downward, so that the elastic block 406 at the bottom of the collecting tube 405 hits the top of the lower tower plate 201, achieving intermittent impact on the top of the tower plate 201, and thereby utilizing the rapid up and down movement of the tower plate 201 to achieve intermittent impact of the elastic member 408 and the elastic block 406 on the bottom and top of the tower plate 201 respectively, causing the tower plate 201 to vibrate and shake off impurities attached to the pores 202. Therefore, the present invention achieves cleaning of the pores 202 through the coordinated cooperation between the adjustment component 3 and the detection component 4, thereby preventing the tower plate 201 from being blocked during use.

[0039] In addition, after long-term use, more impurities will be attached to the surface of the tower tray 201 and the inner wall of the downcomer 204, thereby accelerating the corrosion of the surface of the tower tray 201 and the downcomer 204. Therefore, the following improvements are made: A cleaning portion is provided on the bottom surface of the cover plate 501, and the cleaning portion is preferably a soft brush.

[0040] The cover plate 501 is an arc-shaped structure, and the cover plate 501 matches the inner cross-sectional dimension of the downcomer 204 .

[0041] After the air holes 202 are cleaned by the above method, the surface of the tower plate 201 is cleaned. During cleaning, the telescopic part 502 is extended to drive the cover plate 501 to move horizontally, so that the cover plate 501 corresponds to the position of the air holes 202 at the edge position, and then the adjustment component 3 is used to move the tower plate 201 upward until the tower plate 201 contacts the bottom cleaning part of the cover plate 501, and then the telescopic part 502 is used to move horizontally to drive the cover plate 501 and the bottom cleaning part to reciprocate horizontally, so as to achieve the cleaning of the surface of the tower plate 201. The cleaning portion 204 is clean, and the length of the cleaning portion is sufficient to cover the width of the pores 202. At the same time, clean water or special cleaning liquid is introduced into the tower body 1 from the liquid inlet pipe 106 and flows through each tower plate 201 from top to bottom at a time, so that the impurities cleaned from the tower plate 201 can be washed to the bottom of the tower body 1 and discharged from the drain pipe 103, thereby completing the cleaning of the surface of the tower plate 201. Therefore, the present invention realizes the cleaning of the surface of the tower plate 201 through the linkage cooperation between the adjustment component 3 and the auxiliary component 5, thereby delaying the corrosion of the surface of the tower plate 201.

[0042] When cleaning the inner wall of the downcomer 204, each regulating motor 304 is started synchronously so that each tray 201 drives the downcomer 204 to move upward, and the cover plate 501 is extended into the downcomer 204. The side of the cover plate 501 can be used to scrape and clean the impurities attached to the inner wall of the downcomer 204.

[0043] Embodiment 3 This embodiment discloses a methylamine purification process, comprising the following steps: S1, after preheating the material from the extraction tower, select the liquid inlet pipe 106 located between the distillation section and the stripping section to feed the material, and the incoming liquid passes through each tray assembly 2 in an interlaced manner from top to bottom; S2, the reboiler at the bottom of the tower body 1 inputs steam into the tower body 1 through the steam inlet pipe 105 to heat the incoming liquid, and the steam flow rate is accurately controlled by adjusting the opening of the steam inlet valve to control the vaporization amount of the tower bottom liquid; S3, the vaporized steam carries energy and mass from bottom to top through the air holes 202 on the tray 201 and enters the upper tray assembly 2. On each tray assembly 2, the rising steam fully contacts the liquid overflowing from the upper tray assembly 2. S4, the volatile components of methylamine in the steam diffuse into the liquid phase, while the non-volatile components of water in the liquid phase diffuse into the gas phase. During multiple gas-liquid contacts, the light components of methylamine gradually accumulate at the top of the tower body 1 and are discharged through the gas-liquid separator 110 and the steam outlet pipe 108, and the heavy components such as water move to the bottom of the tower body 1, achieving preliminary separation; S5. When flooding occurs, the distance between each tray assembly 2 is adjusted by the adjusting assembly 3 to reduce the risk of flooding. When the air hole 202 is blocked, the air hole 202 is cleared by the cooperation of the adjusting assembly 3 and the detecting assembly 4. S6, the steam at the top of the tower body 1 enters the condenser and condenses into liquid and flows into the external reflux tank. A part of the liquid returns to the top of the tower body 1 through the reflux pipe 107 as reflux liquid and flows down along the tray assembly 2 to continue mass and heat transfer with the rising steam for further separation, and the other part is extracted as the product; S7, the methylamine product taken from the top of the tower body 1 is transported to the product storage tank through a pipeline and an online mass analyzer is set to monitor the indicators of methylamine in real time. The mixture of monomethylamine and dimethylamine taken from the top of the tower is sent to a separation tower for further separation, and the liquid at the bottom of the tower body 1 is discharged through the drain pipe 103.

[0044] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A methylamine distillation device, comprising a tower body (1), wherein a skirt (101) is provided at the bottom of the tower body (1), a manhole (102) is provided on the side of the skirt (101), a liquid discharge pipe (103) is provided at the bottom of the tower body (1), a ventilation hole (104) is provided on the side of the skirt (101), a steam introduction pipe (105) is provided at the bottom of the side of the tower body (1), a liquid inlet pipe (106) is provided at the side of the tower body (1), a reflux pipe (107) and a tower body (1) top suspension column (109) are provided on both sides of the top of the side of the tower body (1), a steam outlet pipe (108) is provided at the top of the tower body (1), and a gas-liquid separator (110) is provided on the inner top side of the tower body (1), characterized in that: The tower body (1) is provided with tower plate assemblies (2) in a vertically staggered manner inside; The tower plate assembly (2) comprises a tower plate (201), the tower plate (201) being slidably matched with the inner wall of the tower body (1), the middle of the tower plate (201) being evenly provided with air holes (202), an overflow weir (203) being provided on one side of the tower plate (201), and a downcomer (204) penetrating the other side of the tower plate (201), the downcomer (204) being an arc-shaped structure, and two tower plates (201) adjacent to each other are arranged in a staggered manner.

2. A methylamine separation and purification component, suitable for the methylamine distillation equipment according to claim 1, comprising a tray component (2), characterized in that: It also includes an adjustment component (3) evenly arranged on the side of the tower body (1) from top to bottom, a detection component (4) arranged at the bottom of the tower plate component (2), and auxiliary components (5) staggeredly arranged on both sides of the inner wall of the tower body (1), wherein the auxiliary components (5) are located on the upper side of the tower plate component (2); The adjustment assembly (3) comprises a vertically evenly distributed guide rail seat (301), the guide rail seat (301) being embedded in the side of the tower body (1), a sealing sliding seat (303) being slidably connected inside the guide rail seat (301), and a screw rod (302) being vertically rotatably connected in the middle of the guide rail seat (301); The detection assembly (4) comprises a hollow rod (402) and a sliding rod (403) which are arranged obliquely, the hollow rod (402) being slidably sleeved on the outside of the sliding rod (403), the end of the hollow rod (402) being hinged to the bottom surface of the tower plate (201) via a hinge seat (401), the outer end of each sliding rod (403) being hinged to a collecting cylinder (405), and the top surface of the sliding rod (403) being provided with an elastic member (408) via a fixing rod (407); The auxiliary component (5) comprises cover plates (501) staggeredly distributed in the vertical direction and a telescopic portion (502) arranged horizontally, a support rod (504) being provided at the bottom of the telescopic end of the telescopic portion (502) via a mounting seat (503), and the support rod (504) being fixedly connected to the top of the cover plate (501).

3. The separation and purification assembly according to claim 2, characterized in that: The guide rail seat (301) corresponds to the position of the tower plate (201); the sealing slide seat (303) is an arc-shaped structure; the arc-shaped surface of the sealing slide seat (303) is fixedly connected to the side surface of the tower plate (201); and a liquid level meter is provided on the tower plate (201).

4. The separation and purification assembly according to claim 2, characterized in that: The screw rod (302) is threadedly connected to the sealing sliding seat (303); an adjusting motor (304) is provided at the bottom of the guide rail seat (301); and an output shaft of the adjusting motor (304) is fixedly connected to the end of the screw rod (302).

5. The separation and purification assembly according to claim 2, characterized in that: The hollow rods (402) are distributed in a circular array on the bottom surface of the tower plate (201), the upper surfaces of the sliding rods (403) and the hollow rods (402) are respectively provided with grooves, and a spring (404) is provided between the end of the sliding rod (403) and the inner end surface of the hollow rod (402).

6. The separation and purification assembly according to claim 2, characterized in that: An elastic block (406) is provided at the bottom of the collecting cylinder (405), a liquid level sensor is provided inside the collecting cylinder (405), and a liquid drain valve is provided at one side of the bottom of the collecting cylinder (405).

7. The separation and purification assembly according to claim 2, characterized in that: The cover plate (501) is located above the downcomer (204); the cover plate (501) is an arc-shaped structure; the cover plate (501) matches the internal cross-sectional dimensions of the downcomer (204); a cleaning portion is provided on the bottom surface of the cover plate (501); and a fixed end of the telescopic portion (502) is provided on the inner wall of the tower body (1).

8. A methylamine purification process, wherein the separation and purification assembly according to claim 2 is used to purify methylamine during production, wherein: The following steps are involved: S1, after preheating the material from the extraction tower, select the liquid inlet pipe (106) located between the distillation section and the stripping section to feed the material, and the incoming liquid passes through each tray assembly (2) in an alternating manner from top to bottom; S2, the reboiler at the bottom of the tower body (1) inputs steam into the tower body (1) through the steam inlet pipe (105) to heat the incoming liquid, and the steam flow rate is accurately controlled by adjusting the opening of the steam inlet valve to control the vaporization amount of the liquid in the tower bottom; S3, the vaporized steam carries energy and mass from bottom to top through the air holes (202) on the tray (201) and enters the upper tray assembly (2). On each tray assembly (2), the rising steam fully contacts the liquid overflowing from the upper tray assembly (2); S4, the volatile component of methylamine in the steam diffuses into the liquid phase, while the non-volatile component of water in the liquid phase diffuses into the gas phase. During multiple gas-liquid contact processes, the light component of methylamine gradually accumulates at the top of the tower body (1) and is discharged through the gas-liquid separator (110) and the steam outlet pipe (108), while the heavy component of water moves to the bottom of the tower body (1), thereby achieving preliminary separation; S5. When a flooding condition occurs, the distance between each tower plate assembly (2) is adjusted by using the adjustment assembly (3) to reduce the risk of flooding. When the air hole (202) is blocked, the air hole (202) is cleared by cooperating with the adjustment assembly (3) and the detection assembly (4); S6, the steam at the top of the tower body (1) enters the condenser and condenses into liquid and flows into the external reflux tank. A portion of the liquid is returned to the top of the tower body (1) through the reflux pipe (107) as reflux liquid and flows down along the tower plate assembly (2), continuing to transfer mass and heat with the rising steam for further separation, and the other portion is extracted as a product; S7. The methylamine product extracted from the top of the tower body (1) is transported to a product storage tank through a pipeline and an online mass analyzer is set to monitor the methylamine index in real time. The mixture of monomethylamine and dimethylamine extracted from the top of the tower is sent to a separation tower for further separation. The liquid at the bottom of the tower body (1) is discharged through a drain pipe (103).

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