Methylamine separation and purification system and purification method

Abstract

The invention provides a methylamine separation and purification system and a purification method, and belongs to the technical field of methylamine separation and purification, the methylamine separation and purification system comprises a rectifying tower, a cylindrical condenser is fixedly mounted at the upper part in the rectifying tower, a gas flow pipeline for circulation of boil-off gas is arranged in the condenser, the part outside the gas flow pipeline in the condenser is a refrigerant cavity, and the refrigerant cavity is communicated with the rectifying tower. One side of the condenser communicates with a refrigerant inlet extending out of the rectifying tower, a lower supporting hollow column communicating with the refrigerant cavity is fixedly installed at the axis of the bottom of the condenser, and the top of the lower supporting hollow column extends out of the condenser and is rotationally provided with a rotating mechanism; according to the scheme, the condenser is arranged in the rectifying tower, condensate accumulation is prevented, the condensation efficiency is improved, steam is disturbed through the rotating mechanism, secondary condensation is carried out, the product purity is improved, in addition, the reflux ratio of condensate is automatically adjusted through the reflux tank, the system flexibility is improved, the structure is simple, maintenance is convenient, and the cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of methylamine separation and purification, and in particular to a methylamine separation and purification system and a purification method. Background Art

[0002] Methylamine, including monomethylamine, dimethylamine and trimethylamine, is an important basic organic chemical raw material, which is widely used in many industries such as pharmaceuticals, agricultural chemicals, fuel and pigment manufacturing, and new energy technologies. In industry, methylamine is mainly produced by methanol amination, that is, methanol and ammonia react in the gas phase under the action of a catalyst to produce methylamine. Subsequently, monomethylamine, dimethylamine and trimethylamine are further separated through the distillation process.

[0003] However, in actual production processes, raw materials are not always completely pure. For example, methanol may contain impurities such as ethanol, propanol, and other trace organic compounds. These impurities not only affect the quality of the final product, but may also lead to the formation of by-products. In addition, water is produced during the preparation of methylamine.

[0004] The separation and purification of the target product usually relies on distillation, and distillation is mainly completed by reflux. Reflux is one of the key factors to maintain the temperature gradient in the distillation tower. Selecting a suitable reflux ratio helps to improve the separation efficiency and ensure the purity of the product. In this process, light components such as methylamine evaporate from the top of the distillation tower in the form of gas, and reflux to the top of the tower after being partially condensed by the condenser, and the incompletely condensed steam is collected as the product. However, some heavy components such as water, higher amine by-products or incompletely reacted methanol may be carried out by the air flow and cooled in the condenser to form condensate, which will accumulate inside the condenser and cover the heat exchange surface, hindering heat transfer, thereby reducing the heat exchange efficiency of the condenser, and thus affecting the efficiency and stability of the entire distillation process. In addition, some large chemical companies usually use automatic control systems to adjust the reflux ratio, but the cost of such systems is relatively high. Many small and medium-sized enterprises prefer to use a fixed reflux ratio and adjust it manually, but it is difficult to flexibly respond to changes in the situation in the tower. Summary of the invention

[0005] The object of the present invention is to provide a methylamine separation and purification system and a purification method to solve the problems raised in the above background technology.

[0006] To achieve the above purpose, the present invention provides a methylamine separation and purification system adopts the following technical scheme:

[0007] A methylamine separation and purification system comprises a distillation tower,

[0008] The characterizing feature is that: a columnar condenser is fixedly installed on the upper part of the distillation tower, an airflow pipe for the circulation of evaporated gas is provided in the condenser, the part other than the airflow pipe in the condenser is a refrigerant cavity, one side of the condenser is connected with a refrigerant inlet extending out of the distillation tower, a lower supporting hollow column connected with the refrigerant cavity is fixedly installed at the bottom axis of the condenser, the top of the lower supporting hollow column extends out of the condenser and is rotatably installed with a rotating mechanism, an upper supporting hollow column is rotatably installed on the top of the rotating mechanism, and the upper supporting hollow column is connected with a refrigerant outlet extending to the outside of the distillation tower;

[0009] The rotating mechanism comprises a hollow shaft and rotating blades circumferentially mounted on the hollow shaft, a guide baffle is provided inside the hollow shaft to divide it into an upper chamber and a lower chamber, the lower chamber is connected to the refrigerant cavity, the upper chamber is connected to the refrigerant outlet, and blade cavities are provided inside the rotating blades to facilitate the refrigerant to flow from the lower chamber to the upper chamber;

[0010] A reflux tank is fixedly installed on the outside of the distillation tower, and the reflux tank is provided with a condensate collection channel connected to the distillation tower. A connecting shaft is rotatably installed at the axis of the reflux tank, and the connecting shaft is rotatably connected to the rotating mechanism through a transmission connecting rod. A sleeve is slidably installed on the outside of the connecting shaft, and a flyweight for driving the sleeve to rise and fall is hinged between the connecting shaft and the sleeve. A reflux interface for refluxing into the distillation tower is fixedly installed on the bottom of the reflux tank, and the bottom of the sleeve is socket-connected to the reflux interface, and the socket section of the sleeve is provided with a plurality of reflux ports for the outflow of condensate.

[0011] As a further improvement, the adjacent walls of the condenser and the distillation tower are fixedly installed and fit tightly; an air flow duct is provided in the condenser, the air flow duct is spirally arranged from bottom to top, the air flow duct has a plurality of steam inlets and steam outlets, the steam inlets are evenly distributed at the bottom of the condenser, and the steam outlets are evenly arranged at the top of the condenser.

[0012] As a further improvement, the top of the condenser is hemispherical, and it forms a guide groove with the inner wall of the distillation tower for directing the condensate to the reflux tank. The guide groove is connected to the condensate collection channel, and the top of the condensate collection channel is hinged with a one-way blade for one-way flow of the condensate to the reflux tank.

[0013] As a further improvement, the part of the lower supporting hollow column inside the condenser is provided with a plurality of passage openings for facilitating the refrigerant to enter the rotating mechanism, and a traction frame for stabilizing the upper supporting hollow column is fixedly installed on the top of the distillation tower, and the traction frame is fixedly connected to the top of the upper supporting hollow column, and the lower supporting hollow column, the rotating mechanism and the upper supporting hollow column are coaxial.

[0014] As a further improvement, there are several rotating blades, all of which are fixedly mounted on a hollow shaft, and an inclination angle is provided between the rotating blades and the hollow shaft to facilitate the steam to drive their rotation; an S-shaped blade cavity is provided inside the rotating blades, and the inlet and outlet of the blade cavity are provided on the end surface where the rotating blade contacts the hollow shaft, the lower chamber is connected to the inlet of the blade cavity, and the upper chamber is connected to the outlet of the blade cavity.

[0015] As a further improvement, the end of the transmission connecting rod close to the rotating mechanism is rotationally connected to the hollow shaft through bevel gear 1, and the end of the transmission connecting rod away from the rotating mechanism is rotationally connected to the connecting shaft through bevel gear 2.

[0016] As a further improvement, a rotating block is rotatably installed on the top of the sleeve, a guide groove is opened on the side wall of the sleeve, and a guide block is provided at the position where the end face of the reflux tank contacts the guide groove. The guide groove and the guide block are installed in coordination to limit the sleeve to only lifting and lowering movements.

[0017] As a further improvement, the fly hammer includes a connecting rod and a counterweight ball detachably mounted at one end of the connecting rod, the end of the connecting rod away from the counterweight ball is hinged on the connecting shaft, a traction rod is hinged on the connecting rod between the connecting shaft and the counterweight ball, and the end of the traction rod away from the connecting rod is hinged on the rotating block.

[0018] As a further improvement, the reflux interface is connected to the interior of the distillation tower through a reflux pipeline.

[0019] The present invention also provides a method for separating and purifying methylamine, which uses the above-mentioned methylamine separation and purification system and comprises the following steps:

[0020] S1. Continuously charging the refrigerant into the refrigerant cavity through the refrigerant inlet and filling it up. Then, the refrigerant flows into the lower supporting hollow column through the channel opening, thereby entering the lower chamber of the rotating mechanism. In the rotating mechanism, the refrigerant passes through the blade cavity inside the rotating blade, flows from the lower chamber to the upper chamber, and then continues to flow upward, passes through the upper supporting hollow column, and finally flows out from the refrigerant outlet;

[0021] S2. The evaporated gas in the distillation tower enters the gas flow pipeline through the steam inlet for preliminary condensation. The preliminary condensed heavy components flow out directly from the steam inlet under the action of gravity, and the uncondensed steam flows out evenly from the steam outlet at the top of the condenser;

[0022] S3, the steam flowing out of the condenser rises, pushing the rotating blades to rotate, and the rotating blades disturb the gas while rotating, and fully contact with it for heat exchange. The gas after heat exchange forms condensate on the surface of the rotating blades, and is thrown out to the inner wall of the distillation tower under the action of centrifugal force. Then the condensate flows into the guide groove under the action of gravity, and finally enters the reflux tank through the condensate collection channel;

[0023] S4. Steam drives the rotating blades to rotate, and the hollow shaft rotates. The hollow shaft drives the connecting shaft to rotate through the transmission connecting rod. At this time, the fly hammer rotates synchronously with the connecting shaft to generate centrifugal force. The fly hammer rises and causes the sleeve to rise through the traction rod. The reflux port on the sleeve is connected to the reflux tank. The condensate enters the reflux pipe through the reflux port and refluxes to the distillation tower. When the steam flow rate is large, the hollow shaft rotates quickly and the centrifugal force of the fly hammer is large. At this time, the sleeve rises greatly, the number of reflux ports connected increases, and the reflux volume increases. When the steam flow rate decreases, the hollow shaft rotates less, the centrifugal force of the fly hammer decreases, the number of reflux ports connected decreases, and the reflux volume decreases.

[0024] The beneficial effects of the above technical solution of the present invention are as follows:

[0025] 1. This solution places the condenser inside the distillation tower, significantly shortening the path distance required for steam to flow into the condenser. The condensate in the air flow pipeline can be directly discharged through the steam inlet. This design avoids the accumulation of condensate, which not only improves the condensation efficiency, but also effectively reduces energy consumption, thereby reducing the overall operating cost;

[0026] 2. A rotating mechanism is set above the condenser to disturb the steam flowing out of the condenser through rotating blades. This disturbance further promotes the condensation of heavy components in the steam. The condensate enters the reflux tank for storage through the condensate collection channel. This design significantly improves the purity of the target product and ensures higher product quality.

[0027] 3. By setting up a reflux tank linked to the rotating mechanism, the system can automatically adjust the reflux rate according to the change of steam flow. This design increases the flexibility of the system, enabling it to adapt to different operating conditions and maintain high product quality. At the same time, it has a simple structure, easy maintenance and relatively low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 A schematic top view of the structure of the present invention

[0031] Figure 3 It is a structural schematic diagram of the rotating mechanism of the present invention;

[0032] Figure 4 It is a schematic diagram of the internal structure of the rotating mechanism of the present invention;

[0033] Figure 5 It is a schematic diagram of the internal structure of the rotary blade of the present invention;

[0034] Figure 6 It is a structural schematic diagram of the reflux tank of the present invention;

[0035] Figure 7 It is a structural schematic diagram of the sleeve of the present invention;

[0036] Figure 8 It is a schematic diagram of the internal structure of the sleeve of the present invention.

[0037] Description of reference numerals:

[0038] 1. Distillation tower; 2. Condenser; 21. Air flow duct; 211. Steam inlet; 212. Steam outlet; 22. Refrigerant cavity; 23. Refrigerant inlet; 24. Lower supporting hollow column; 241. Passageway; 25. Rotating mechanism; 251. Hollow shaft; 252. Rotating blade; 253. Guide baffle; 254. Upper chamber; 255. Lower chamber; 256. Blade cavity; 26. Upper supporting hollow column; 27. Refrigerant outlet; 28. Traction frame; 3. Return Flow tank; 31. Condensate collection channel; 311. One-way blade; 32. Connecting shaft; 33. Transmission connecting rod; 331. Bevel gear one; 332. Bevel gear two; 34. Sleeve; 341. Rotating block; 342. Guide groove; 343. Guide block; 344. Return port; 345. Sealing ring; 35. Return interface; 36. Return pipe; 37. Guide groove; 38. Fly hammer; 381. Counterweight ball; 382. Drawbar; 383. Connecting rod; 39. Bracket. DETAILED DESCRIPTION

[0039] 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. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0041] During the distillation of methylamine, heavy components may be carried out of the distillation tower 1 by the vapor flow and form condensate in the condenser 2. These condensates will accumulate inside the condenser 2 and cover the heat exchange surface, thereby hindering heat transfer and reducing the heat exchange efficiency of the condenser 2. At the same time, the reflux ratio is a key parameter in the distillation process. An appropriate reflux ratio can maintain the temperature gradient in the tower, improve the separation efficiency, and control the purity of the top product.

[0042] For large modern industrial distillation units, automatic control systems are usually used to adjust the reflux ratio to achieve optimal operating conditions. However, such systems are expensive and are not always a viable option for small and medium-sized chemical companies. These companies tend to set a fixed reflux ratio and adjust it manually, but this makes it difficult to flexibly respond to changes in the tower conditions.

[0043] In order to solve the above problems, the present solution places the condenser 2 inside the distillation tower 1 and installs a rotating mechanism 25 above it. In addition, a reflux tank 3 linked to the rotating mechanism 25 is provided outside the tower. During operation, the steam first passes through the condenser 2 for preliminary condensation, and the condensed liquid falls into the tower through the steam inlet 211 by gravity, thereby avoiding the accumulation of condensate in the condenser 2; the steam that is not completely condensed is discharged from the steam outlet 212, and the rotating mechanism 25 is driven to rotate. The rotation of the rotating mechanism 25 can not only disturb the airflow, but also further promote the condensation of the steam; with the contact of the rotating blades 252, the steam is condensed into liquid, and under the action of centrifugal force, the condensate is thrown to the inner wall of the distillation tower 1, and then flows into the reflux tank 3 through the guide groove 37 and the condensate collection channel 31. The sleeve 34 in the reflux tank 3 can be raised and lowered according to the rotation speed of the rotating mechanism 25, and the number and size of the reflux ports 344 can be adjusted to dynamically adjust the reflux amount to ensure the stability and efficiency of the distillation process.

[0044] After introducing the basic principle of the present invention, various non-limiting embodiments of the present invention are described in detail below. The number of any element in the drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning.

[0045] The principle and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0046] Embodiment 1 of a methylamine separation and purification system provided by the present invention:

[0047] like Figure 1-2 As shown, a methylamine separation and purification system includes a distillation tower 1, in which a columnar condenser 2 is fixedly installed at the upper part of the distillation tower 1. The condenser 2 and the adjacent wall surface of the distillation tower 1 are tightly fitted and fixedly installed, which can effectively prevent steam from flowing out of the distillation tower 1 through the gap between them, so as not to reduce the purity of the product.

[0048] The condenser 2 is provided with an airflow duct 21 for the circulation of the evaporating gas, and the space outside the airflow duct 21 constitutes a refrigerant cavity 22. Through the refrigerant inlet 23 arranged on one side of the condenser 2 and extending to the outside of the distillation tower 1, the refrigerant can smoothly enter the refrigerant cavity 22, thereby providing the necessary cooling capacity for the entire system; the airflow duct 21 adopts a spiral layout from bottom to top, which not only increases the contact time and area between the steam and the refrigerant, but also promotes sufficient heat exchange between the two, so that the heavy components in the steam can be effectively condensed and discharged, avoiding the accumulation of condensate in the condenser 2. The airflow duct 21 corresponds to a number of steam inlets 211 and steam outlets 212. In order to ensure that the rising steam can enter the condenser 2 evenly and fully, the steam inlets 211 are evenly distributed at the bottom of the condenser 2; similarly, the steam outlets 212 are also evenly arranged at the top of the condenser 2, which helps to evenly discharge the steam and provide a stable driving force for the rotating mechanism 25 above. The advantage of this design is that it improves the condensation efficiency and reduces the coverage of the heavy components on the heat exchange surface, thereby maintaining a high heat exchange efficiency; at the same time, the evenly distributed steam inlet 211 and outlet ensure the stability of the steam flow, which is crucial for maintaining the temperature gradient in the distillation tower 1 and improving the separation effect.

[0049] like Figure 1-2 As shown, a lower supporting hollow column 24 connected to the refrigerant cavity 22 is fixedly installed at the axial position of the bottom of the condenser 2, and a plurality of passage openings 241 are provided at the bottom of the hollow column, so that the refrigerant filling the refrigerant cavity 22 can flow into the interior of the lower supporting hollow column 24 through these passage openings 241, and the top of the lower supporting hollow column 24 extends out of the condenser 2 and is rotatably installed with a rotating mechanism 25. An upper supporting hollow column 26 is further rotatably installed on the top of the rotating mechanism 25, and the upper supporting hollow column 26 is connected with a refrigerant outlet 27 extending to the outside of the distillation tower 1.

[0050] like Figure 3-5As shown, the rotating mechanism 25 is composed of a hollow shaft 251 and rotating blades 252 evenly distributed along its circumference. A guide baffle 253 is provided inside the hollow shaft 251 to divide the inside of the shaft into an upper chamber 254 and a lower chamber 255. The lower chamber 255 is connected to the refrigerant cavity 22 through the lower supporting hollow column 24, while the upper chamber 254 is connected to the refrigerant outlet 27 through the upper supporting hollow column 26. There are a number of rotating blades 252, each of which is fixed on the hollow shaft 251 at a certain inclination angle. This design facilitates the steam to drive the blade to rotate. In addition, each rotating blade 252 has an S-shaped blade cavity 256 inside, and the inlet and outlet of these cavities are located on the end surface where the rotating blade 252 contacts the hollow shaft 251. Corresponding openings are provided on the hollow shaft 251 to ensure that the lower chamber 255 is connected to the inlet of the blade cavity 256, and the upper chamber 254 is connected to the outlet of the blade cavity 256.

[0051] In the whole system, the lower supporting hollow column 24, the rotating mechanism 25 and the upper supporting hollow column 26 are all coaxially arranged, and the refrigerant entering the lower supporting hollow column 24 passes through the lower chamber 255, the blade cavity 256 and the upper chamber 254 in sequence under the action of pressure, and finally flows out from the refrigerant outlet 27 through the upper supporting hollow column 26. The rotating mechanism 25 is not only used to disturb the steam, wherein the refrigerant flows through the blade cavity 256 and fully contacts with the steam, so that secondary condensation occurs on the surface of the rotating blade 252, and the generated condensate is then thrown to the inner wall of the distillation tower 1 under the action of centrifugal force and flows down along the inner wall.

[0052] like Figure 1-2 As shown, in order to ensure the stability and reliability of the structure, a traction frame 28 is fixedly installed on the top of the distillation tower 1. The traction frame 28 is cross-shaped, and the end face of the traction frame 28 is fixedly installed inside the distillation tower 1. The center of the traction frame 28 is firmly connected to the top of the upper support hollow column 26 to provide necessary support for the upper support hollow column 26. In addition, a sealed rotation connection method is adopted between the rotating mechanism 25 and the lower support hollow column 24 and the upper support hollow column 26 to prevent refrigerant leakage and ensure the normal operation of the system. This rotation connection method is realized based on the existing technology, which ensures the overall performance and safety of the device and will not be repeated here.

[0053] like Figure 1 and Figure 6 As shown, a reflux tank 3 is fixedly installed on the outside of the distillation tower 1 through a bracket 39, and the reflux tank 3 is connected to the inside of the distillation tower 1 through a condensate collection channel 31. Inside the distillation tower 1, the top of the condenser 2 is designed as a hemispherical structure, and this design forms a guide groove 37 together with the inner wall of the distillation tower 1. The guide groove 37 is connected to the condensate collection channel 31, which is used to collect the condensate flowing down the inner wall of the distillation tower 1 and guide it to the reflux tank 3.

[0054] In order to ensure that the condensate can only flow to the reflux tank 3 in one direction, a hinged one-way blade 311 is installed at the top of the condensate collection channel 31. In this example, the condensate collection channel 31 is tilted, and its higher end is located on the side of the distillation tower 1. The one-way blade 311 is installed vertically, and its height is set to the distance between the top and the bottom in the vertical direction of the condensate collection channel 31. Such a height design allows the one-way blade 311 to be opened only in the direction toward the reflux tank 3, thereby ensuring that the condensate can flow smoothly into the reflux tank 3, and effectively preventing the condensate in the reflux tank 3 from backflowing or overflowing into the distillation tower 1.

[0055] like Figure 1 and Figure 6 As shown, a rotatable connecting shaft 32 is installed at the axis of the reflux tank 3. In this embodiment, the top of the connecting shaft 32 is connected to the transmission connecting rod 33 through a bevel gear 2 332, and the other end of the transmission connecting rod 33 extends to the inside of the distillation tower 1 and is connected to the hollow shaft 251 in the rotating mechanism 25 through a bevel gear 1 331. When the rotating mechanism 25 starts to rotate, it can drive the connecting shaft 32 to rotate synchronously through the transmission connecting rod 33.

[0056] In order to ensure that the portion of the transmission connecting rod 33 passing through the wall of the distillation tower 1 can be effectively sealed and not affect the rotation, a sealed rotating connection method is adopted there. This sealed rotating connection technology is an existing mature technology and will not be described in detail here.

[0057] like Figure 6-8 As shown, a sleeve 34 is slidably mounted on the outside of the connecting shaft 32, a rotating block 341 is rotatably mounted on the top of the sleeve 34, and a set of flyweight 38 system for driving the sleeve 34 to rise and fall is hinged between the connecting shaft 32 and the rotating block 341, and the system includes two flyweights 38 symmetrically mounted on both sides of the connecting shaft 32. Each flyweight 38 is composed of a connecting rod 383 and a counterweight ball 381 detachably mounted on one end of the connecting rod 383, and the end of the connecting rod 383 away from the counterweight ball 381 is hinged on the connecting shaft 32, and a traction rod 382 is also hinged on the connecting rod 383 between the connecting shaft 32 and the counterweight ball 381, and the end of the traction rod 382 away from the connecting rod 383 is hinged on the rotating block 341. In addition, a guide groove 342 is provided on the side wall of the sleeve 34, and a guide block 343 is provided at the position where the reflux tank 3 contacts the guide groove 342. A sliding seal is installed between the guide groove 342 and the guide block 343. This technology is an existing technology and prevents the condensate from leaking through the guide groove 342.

[0058] A protective shell (not marked in the figure) is also provided above the reflux tank 3 to protect the operation of the fly hammer 38, so as to prevent it from being affected by the outside world during operation or causing harm to the operator. A reflux interface 35 is fixedly installed at the bottom of the reflux tank 3, and the interface is connected to the inside of the distillation tower 1 through a reflux pipe 36.

[0059] like Figure 6-8 As shown, the bottom of the sleeve 34 is connected to the reflux interface 35 by a socket-and-spigot connection, and a number of reflux ports 344 are provided on the socket section of the sleeve 34. These reflux ports 344 are used for the condensate to flow out and re-enter the distillation tower 1. A sealing ring 345 is also fixedly installed on the top of the socket section. When the sleeve 34 and the reflux interface 35 are fully socketed, the reflux ports 344 are all located inside the reflux interface 35 and are sealed, so that the condensate cannot flow out through the reflux ports 344. In addition, the interior of the sleeve 34 is divided into two isolated spaces, the upper space is used for the sleeve connection shaft 32, and the lower space is used for the condensate to flow out. The isolated design prevents the condensate from overflowing the reflux tank 3 through the interior of the sleeve 34.

[0060] When the system is running, the connecting shaft 32 drives the flyweight 38 to rotate synchronously, the counterweight ball 381 is lifted and lowered under the action of centrifugal force, and the traction rod 382 drives the rotating block 341 and the sleeve 34 to lift and lower. The design of the rotating block 341, the guide groove 342 and the guide block 343 cooperates with each other to ensure that the sleeve 34 can only perform vertical lifting and lowering movements to prevent it from lateral displacement. The design of the guide groove 342 and the guide block 343 also limits the lifting path mileage of the sleeve 34 to prevent the sleeve 34 from exceeding the path, thereby improving the stability and reliability of the system. In addition, by adjusting the position of the counterweight of the flyweight 38 and the traction rod 382, ​​the lifting height of the sleeve 34 can be adjusted, and the number and size of the reflux ports 344 can be adjusted by adjusting the lifting height of the sleeve 34, thereby controlling the reflux amount of the condensate.

[0061] This mechanical structure design not only realizes the lifting and lowering control of the sleeve 34, but also ensures that the condensate can smoothly return from the reflux tank 3 to the distillation tower 1, thereby dynamically adjusting the reflux ratio and maintaining the stable operation of the distillation process.

[0062] The present invention also provides a method for separating and purifying methylamine, which uses the above-mentioned methylamine separation and purification system and comprises the following steps:

[0063] S1. Continuously charge the refrigerant into the refrigerant cavity 22 through the refrigerant inlet 23 and fill it up. Then, the refrigerant flows into the lower supporting hollow column 24 through the channel opening 241, and then enters the lower chamber 255 of the rotating mechanism 25. In the rotating mechanism 25, the refrigerant passes through the blade cavity 256 inside the rotating blade 252, flows from the lower chamber 255 to the upper chamber 254, and then continues to flow upward, passes through the upper supporting hollow column 26, and finally flows out from the refrigerant outlet 27.

[0064] S2, the evaporated gas in the distillation tower 1 enters the gas flow pipe 21 through the steam inlet 211, and is initially condensed. The initially condensed heavy components flow out directly from the steam inlet 211 under the action of gravity, and the uncondensed steam flows out evenly from the steam outlet 212 at the top of the condenser 2;

[0065] S3, the steam flowing out of the condenser 2 rises, pushing the rotating blades 252 to rotate, and the rotating blades 252 turbulently flow the gas while rotating, and fully contact with the gas for heat exchange, and the steam part after heat exchange forms condensate on the surface of the rotating blades 252, and is thrown out to the inner wall of the distillation tower 1 under the action of centrifugal force, and then the condensate flows into the guide groove 37 under the action of gravity, and finally enters the reflux tank 3 through the condensate collection channel 31;

[0066] S4, steam drives the rotating blades 252 to rotate, and the hollow shaft 251 rotates. The hollow shaft 251 drives the connecting shaft 32 to rotate through the transmission connecting rod 33. At this time, the fly hammer 38 rotates synchronously with the connecting shaft 32 to generate centrifugal force. The fly hammer 38 rises and causes the sleeve 34 to rise through the traction rod 382. The reflux port 344 on the sleeve 34 is connected to the reflux tank 3, and the condensate enters the reflux pipe 36 through the reflux port 344 and refluxes to the distillation tower 1; when the steam flow rate is large, the speed of the hollow shaft 251 is fast, and the centrifugal force of the fly hammer 38 is large. At this time, the sleeve 34 rises greatly, the number of reflux ports 344 connected increases, and the reflux amount increases; when the steam flow rate decreases, the speed of the hollow shaft 251 decreases, the centrifugal force of the fly hammer decreases, the number of reflux ports 344 connected decreases, and the reflux amount decreases.

[0067] The above-mentioned ideal embodiments of the present invention are used as inspiration, but it is obvious to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will think of many changes, modifications and alternatives without departing from the thought and spirit of the present invention. It should be understood that in the process of practicing the present invention, various alternatives to the embodiments of the present invention described herein may be adopted. The attached claims are intended to define the scope of protection of the present invention, and therefore cover the modular composition, equivalent or alternatives within the scope of protection of these claims.

Claims

1. A methylamine separation and purification system, comprising a distillation tower (1), Features: A columnar condenser (2) is fixedly installed at the upper part of the distillation tower (1), and a gas flow pipeline (21) for evaporation gas to flow is provided in the condenser (2). The part outside the gas flow pipeline (21) in the condenser (2) is a refrigerant cavity (22). One side of the condenser (2) is connected to a refrigerant inlet (23) extending outside the distillation tower (1). A lower supporting hollow column (24) connected to the refrigerant cavity (22) is fixedly installed at the bottom axis of the condenser (2). The top of the lower supporting hollow column (24) extends out of the condenser (2) and is rotatably installed with a rotating mechanism (25). The top of the rotating mechanism (25) is rotatably installed with an upper supporting hollow column (26), and the upper supporting hollow column (26) is connected to a refrigerant outlet (27) extending to the outside of the distillation tower (1); The rotating mechanism (25) comprises a hollow shaft (251) and a rotating blade (252) circumferentially mounted on the hollow shaft (251); a flow guide baffle (253) is provided inside the hollow shaft (251) to divide the hollow shaft (251) into an upper chamber (254) and a lower chamber (255); the lower chamber (255) is connected to the refrigerant cavity (22); the upper chamber (254) is connected to the refrigerant outlet (27); and blade cavities (256) are provided inside the rotating blades (252) to facilitate the refrigerant to flow from the lower chamber (255) to the upper chamber (254); A reflux tank (3) is fixedly mounted on the outside of the distillation tower (1). The reflux tank (3) is provided with a condensate collection channel (31) connected to the distillation tower (1). A connecting shaft (32) is rotatably mounted at the axis of the reflux tank (3). The connecting shaft (32) is rotatably connected to a rotating mechanism (25) via a transmission connecting rod (33). A sleeve (34) is slidably mounted on the outside of the connecting shaft (32). A flyweight (38) for driving the sleeve (34) to rise and fall is hingedly connected between the connecting shaft (32) and the sleeve (34). A reflux interface (35) for reflux into the distillation tower (1) is fixedly mounted on the bottom of the reflux tank (3). The bottom of the sleeve (34) is connected to the reflux interface (35) in a socket-type manner, and the socket section of the sleeve (34) is provided with a plurality of reflux ports (344) for condensate to flow out.

2. A methylamine separation and purification system according to claim 1, characterized in that: The condenser (2) and the adjacent wall surfaces of the distillation tower (1) are fixedly installed and closely fitted; an airflow duct (21) is provided in the condenser (2), the airflow duct (21) is spirally arranged from bottom to top, the airflow duct (21) has a plurality of steam inlets (211) and steam outlets (212), the steam inlets (211) are evenly distributed at the bottom of the condenser (2), and the steam outlets (212) are evenly arranged at the top of the condenser (2).

3. A methylamine separation and purification system according to claim 1, characterized in that: The top of the condenser (2) is hemispherical and forms a guide groove (37) with the inner wall of the distillation tower (1) for guiding the condensate to the reflux tank (3). The guide groove (37) is connected to the condensate collection channel (31). The top of the condensate collection channel (31) is hinged with a one-way blade (311) for one-way flow of the condensate to the reflux tank (3).

4. A methylamine separation and purification system according to claim 1, characterized in that: The lower supporting hollow column (24) is provided with a plurality of passage openings (241) in the condenser (2) for facilitating the refrigerant to enter the rotating mechanism (25). A traction frame (28) for stabilizing the upper supporting hollow column (26) is fixedly installed at the top of the distillation tower (1). The traction frame (28) is fixedly connected to the top of the upper supporting hollow column (26). The lower supporting hollow column (24), the rotating mechanism (25) and the upper supporting hollow column (26) are coaxial.

5. A methylamine separation and purification system according to claim 1, characterized in that: There are a plurality of rotating blades (252), all of which are fixedly mounted on the hollow shaft (251); an inclination angle is provided between the rotating blades (252) and the hollow shaft (251) to facilitate steam to drive the rotating blades (252) to rotate; each rotating blade (252) is provided with an S-shaped blade cavity (256); the inlet and outlet of the blade cavity (256) are arranged on the end surface where the rotating blade (252) contacts the hollow shaft (251); the lower chamber (255) is communicated with the inlet of the blade cavity (256), and the upper chamber (254) is communicated with the outlet of the blade cavity (256).

6. A methylamine separation and purification system according to claim 1, characterized in that: The end of the transmission connecting rod (33) close to the rotating mechanism (25) is rotationally connected to the hollow shaft (251) through a bevel gear 1 (331), and the end of the transmission connecting rod (33) away from the rotating mechanism (25) is rotationally connected to the connecting shaft (32) through a bevel gear 2 (332).

7. A methylamine separation and purification system according to claim 1, characterized in that: A rotating block (341) is rotatably mounted on the top of the sleeve (34), a guide groove (342) is provided on the side wall of the sleeve (34), a guide block (343) is provided at a position where the end surface of the reflux tank (3) contacts the guide groove (342), and the guide groove (342) and the guide block (343) are installed in coordination to restrict the sleeve (34) to only be able to perform lifting and lowering movements.

8. A methylamine separation and purification system according to claim 7, characterized in that: The flyweight comprises a connecting rod (383) and a counterweight ball (381) detachably mounted on one end of the connecting rod (383); one end of the connecting rod (383) away from the counterweight ball (381) is hinged on a connecting shaft (32); a traction rod (382) is hinged on the connecting rod (383) between the connecting shaft (32) and the counterweight ball (381); and one end of the traction rod (382) away from the connecting rod (383) is hinged on a rotating block (341).

9. A methylamine separation and purification system according to claim 1, characterized in that: The reflux interface (35) is connected to the interior of the distillation tower (1) via a reflux pipeline (36).

10. A method for separating and purifying methylamine, using the methylamine separation and purification system according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Continuously charging the refrigerant into the refrigerant cavity (22) through the refrigerant inlet (23) and filling it up. Then, the refrigerant flows into the lower supporting hollow column (24) through the channel opening (241), thereby entering the lower chamber (255) of the rotating mechanism (25). In the rotating mechanism (25), the refrigerant passes through the blade cavity (256) inside the rotating blade (252), flows from the lower chamber (255) to the upper chamber (254), then continues to flow upward, passes through the upper supporting hollow column (26), and finally flows out from the refrigerant outlet (27); S2, the evaporated gas in the distillation tower (1) enters the gas flow pipe (21) through the steam inlet (211) and is initially condensed. The initially condensed heavy components flow out directly from the steam inlet (211) under the action of gravity, and the uncondensed steam flows out evenly from the steam outlet (212) at the top of the condenser (2); S3, the steam flowing out of the condenser (2) rises, pushing the rotating blades (252) to rotate. The rotating blades (252) disturb the gas while rotating, and fully contact the gas for heat exchange. The steam after heat exchange forms condensate on the surface of the rotating blades (252), and is thrown out to the inner wall of the distillation tower (1) under the action of centrifugal force. Then, the condensate flows into the guide groove (37) under the action of gravity, and finally enters the reflux tank (3) through the condensate collection channel (31); S4, steam drives the rotating blade (252) to rotate, the hollow shaft (251) rotates, the hollow shaft (251) drives the connecting shaft (32) to rotate through the transmission connecting rod (33), at this time, the flyweight (38) rotates synchronously with the connecting shaft (32), generating centrifugal force, the flyweight (38) rises and causes the sleeve (34) to rise through the traction rod (382), the reflux port (344) on the sleeve (34) is connected to the reflux tank (3), the condensate enters the reflux pipe (36) through the reflux port (344) and refluxes to the distillation tower (1); when the steam flow rate is large, the rotation speed of the hollow shaft (251) is fast, the centrifugal force of the flyweight (38) is large, at this time the sleeve (34) rises greatly, the number of reflux ports (344) connected increases, and the reflux amount increases; when the steam flow rate decreases, the rotation speed of the hollow shaft (251) decreases, the centrifugal force of the flyweight decreases, the number of reflux ports (344) connected decreases, and the reflux amount decreases.

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