A N-methylaniline residual liquid recovery device and distillation recovery process

Abstract

The invention discloses an N-methylaniline residual liquid recovery device and a distillation recovery process, and relates to the field of distillation kettles. The N-methylaniline residual liquid recovery device comprises a kettle body, a top cover of which is fixed with a coil, and a main part of the coil extends to the inner side of the kettle body; the N-methylaniline residual liquid recovery device can drive waste liquid in a lower layer of an inner cavity of the kettle body to form convection with waste liquid in an upper layer of an inner cavity of the kettle body. Compared with a traditional technical solution, an auger provides upward power for light components in the lower layer, so that they can reach the upper layer faster, thereby accelerating the separation of light components. At the same time, due to the accelerated separation of light components, the probability of remixing of light components with waste liquid is reduced. In addition, in the initial stage of heating, due to the design of a transverse mixed flow channel, waste liquid at a central position of the kettle body and waste liquid at a peripheral position of the inner cavity of the kettle body can form convection, so that heating is more uniform and the heating speed is improved.

Description

Technical Field

[0001] The invention relates to the field of distillation kettles, and in particular to an N-methylaniline residual liquid recovery device and a distillation recovery process. Background Art

[0002] In the hydrolysis recovery process of the distillation residue of N-methylaniline gas phase synthesis method, the distillation residue after vacuum distillation needs to be pumped into a tank body for hydrolysis and vacuum distillation, specifically by adding a strong alkali aqueous solution for mixed hydrolysis, then the air pressure inside the tank body is reduced by vacuum pumping, so as to reduce the distillation boiling point, and then a heat medium is introduced into the coiled pipe in the tank body to achieve the effect of vacuum distillation recovery of N-methylaniline;

[0003] In the traditional technology, the structure of this type of reaction tank is simple. Heating is achieved by arranging coils, and mixing, stirring, heating and stirring are performed by arranging a stirring shaft at the center of the tank. However, in this traditional heating and stirring structural arrangement, during the heating stage, since stirring causes the residual liquid to flow and rotate around the axis of the kettle body, it is difficult for the residual liquid in the center and the peripheral part of the kettle body to achieve convection. As a result, the liquid in the peripheral part of the inner cavity of the kettle body away from the coils and the central part of the inner cavity of the kettle body heats up slowly, the heating is uneven, and the heating speed is slow. In addition, in this heating and stirring structural arrangement, when the boiling point is reached and the gas phase rises, the upper and lower layers of waste liquid cannot form convection. The light components in the lower layer need to overcome the resistance of the upper layer of waste liquid to diffuse upward. The rising speed of the gas phase in the lower layer is slow, which is not conducive to the release of the gas phase in the lower layer to the upper layer. In addition, the rising path of the gas phase in the lower layer is long, and it is easy to remix with the waste liquid during the rising process. Summary of the invention

[0004] In order to make up for the shortcomings of the existing technical problems, the purpose of the present invention is to provide an N-methylaniline residual liquid recovery device and a distillation recovery process, so that the residual liquid at the center of the kettle body and the peripheral part of the inner cavity of the kettle body can convect during the heating stage, thereby accelerating the heating rate. In the steam-raising stage, the upper and lower layers of waste liquid can form convection, so that the lower gas phase is released to the upper layer.

[0005] In order to solve the problems of the prior art, the technical solution of the present invention is as follows:

[0006] An N-methylaniline residual liquid recovery device comprises a kettle body, a coil is fixed on the top cover of the kettle body, and a flow channel is arranged at the center of the inner cavity of the kettle body, and the flow channel is arranged in a vertical shape;

[0007] The inner cavity of the flow channel is provided with a longitudinal mixing flow component, and the inner cavity of the flow channel is composed of a plurality of independent chambers distributed in sequence from top to bottom, and a transverse mixing flow channel connecting the inner circle and the outer circle of the coil is formed on the side wall of each independent chamber;

[0008] The longitudinal mixing flow assembly has two working states, one of which is to close the inlet and outlet of the transverse mixing flow channel, open the top and bottom of the flow channel, connect multiple independent chambers, and transport the residual liquid in the lower layer of the kettle body cavity through the flow channel to the upper layer of the kettle body cavity;

[0009] Another working state of the longitudinal mixing flow component is to isolate adjacent independent chambers so that residual liquid in the inner and outer circles of the coils can enter and exit the independent chambers through the inlet and outlet of the transverse mixing flow channel to achieve convection.

[0010] Preferably, the flow channel is composed of a plurality of flow sleeves fixed in sequence from top to bottom, both ends of the flow sleeve at the top are sealed, and the flow sleeve at the top is fixed to the center of the bottom surface of the top cover, and the remaining flow sleeves are open at the top and closed at the bottom;

[0011] The bottom of the through-flow sleeve is symmetrically provided with a first semicircular spoiler inlet, and the top of the through-flow sleeve at the uppermost end is symmetrically provided with a first semicircular spoiler outlet;

[0012] The inner wall of the through-flow sleeve is rotatably connected to a first cover plate at a position corresponding to the first spoiler inlet via a first torsion hinge, and the top surface of the uppermost through-flow sleeve faces the first spoiler outlet, and is rotatably connected to a second cover plate via a second torsion hinge.

[0013] Preferably, the longitudinal mixed flow assembly includes a transmission shaft rotatably connected to the axial position of the plurality of through-flow sleeves through a bearing, the upper end of the transmission shaft is rotatably connected to the center position of the top cover through a bearing, the upper end of the transmission shaft passes through the top cover and extends to the top of the top cover, a motor is fixed at the center of the top surface of the top cover, and the upper end of the transmission shaft is fixed to the output end of the motor;

[0014] A screw auger is arranged in the middle of each flow-through sleeve, and each screw auger is wound and fixed on the outer wall of the transmission shaft at a corresponding position.

[0015] Preferably, the transverse mixed flow channel includes a plurality of second spoiler inlets distributed on the side wall of the upper end of the flow sleeve in the form of a ring array with the axis of the flow sleeve as the center, and a third cover plate is rotatably connected to the position of the inner wall of the flow sleeve corresponding to the second spoiler inlet through a third torsion hinge, and the flipping direction of the third cover plate is downward flipping;

[0016] It also includes a plurality of spoilers distributed on the side wall of the lower end of the flow sleeve in the form of a circular array with the axis of the flow sleeve as the center, the spoilers are arranged horizontally, and the end of the spoiler away from the flow sleeve extends over the coil to the outer circle of the coil, and the end of the spoiler away from the flow sleeve is rotatably connected to a fourth cover plate through a fourth torsion hinge.

[0017] Preferably, a plurality of the second spoiler inlets and a plurality of spoiler tubes are staggeredly distributed in the longitudinal direction.

[0018] Preferably, the coiled tube is provided with avoidance spaces at positions corresponding to each layer of spoiler tubes from top to bottom, and the avoidance spaces are provided for the spoiler tubes to pass over the coiled tubes.

[0019] Preferably, the spoiler cylinder is rotatably connected to the side wall of the flow sleeve through a bearing, a plurality of active bevel gear rings are fixed on the transmission shaft in sequence from top to bottom, each active bevel gear ring faces a layer of spoiler cylinder, a driven bevel gear ring is fixed on the outer wall of the spoiler cylinder close to one end of the active bevel gear ring, the driven bevel gear ring is meshingly connected with the active bevel gear ring, the spoiler cylinder includes an elbow portion formed at an end thereof away from the flow sleeve and bent 90 degrees, the end of the elbow portion is flat, and the fourth cover plate is rotatably connected to the end of the elbow portion through a fourth torsion hinge, and a plurality of blades are fixed at equal angles on the outer wall of the spoiler cylinder close to one end of the elbow portion.

[0020] Preferably, a plurality of filling pipes are fixed on the top cover in a circular array with the center of the top surface of the top cover as the center, the lower ends of the filling pipes extend into the inner cavity of the kettle body, each filling pipe is located in the interval between two adjacent spoiler cylinders, a plurality of nozzles are fixed on the filling pipes in sequence from top to bottom, each nozzle is opposite to a second spoiler inlet, the upper ends of the plurality of filling pipes extend to the top of the kettle body and are connected with an annular pipe, and a valve body is provided at the inlet of the annular pipe.

[0021] The present invention also provides a distillation and recovery process for N-methylaniline residual liquid, which uses the above-mentioned N-methylaniline residual liquid recovery device to complete the distillation of N-methylaniline residual liquid, and specifically comprises the following steps:

[0022] S1, adding N-methylaniline residual liquid into the kettle;

[0023] S2, adding strong alkaline water to the N-methylaniline residual liquid to make the pH of the residual liquid reach 10-12, and performing a hydrolysis reaction. During the hydrolysis reaction, a heat medium is introduced into the coil, and the residual liquid is heated while the hydrolysis is performed, and the temperature is maintained at 70-100° C.;

[0024] S3. After the hydrolysis reaction is completed, the kettle is evacuated to a predetermined vacuum degree, the vacuum degree is maintained at 10-20 KPa, the temperature is controlled at 140-162°C, and distillation is performed to separate light and heavy components;

[0025] S4. The distillate is sent to the finished product distillation tower for further distillation and purification, and the remaining distillation residue is sent to the distillation residue tank.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] 1. The present invention arranges a flow channel at the center of the inner cavity of the kettle body, and arranges a longitudinal mixing flow component in the flow channel, so that in the steaming stage, the waste liquid in the lower layer of the inner cavity of the kettle body can be driven to form convection with the waste liquid in the upper layer of the inner cavity of the kettle body. Compared with the traditional technical solution, the auger provides an upward force for the light components in the lower layer, so that they can reach the upper layer faster, accelerate the separation of the light components, and at the same time, due to the accelerated separation of the light components, the probability of re-mixing of the light components and the waste liquid is reduced; and in the initial stage of heating, due to the design of the horizontal mixing flow channel, the waste liquid at the center of the kettle body and the waste liquid at the peripheral position of the inner cavity of the kettle body can form convection, so that the waste liquid continuously passes through the gap between the coils, and the waste liquid at different positions is constantly close to the coils, so that the heating is more uniform, the heating speed is improved, and the problem of slow progressive heating of the waste liquid from the part close to the coils to the part far away from the coils is solved;

[0028] 2. The present invention arranges a plurality of longitudinal filling pipes, and each nozzle on the filling pipe faces a second disturbance flow inlet. Thus, in the early stage of vacuum distillation, during the process of adding strong alkaline water for mixed hydrolysis, the strong alkaline water can be added to the residual liquid at multiple positions in the kettle body in layers. At the same time, the horizontal mixed flow channel is used. When the waste liquid at the center of the kettle body forms convection with the waste liquid at the peripheral position of the inner cavity of the kettle body, the added strong alkaline water is continuously mixed into the convection. This multi-position and multi-level design, which gradually mixes into the convection waste liquid, enables the strong alkaline water to be more fully mixed with the waste liquid in a shorter time. Compared with the traditional stirring form of stirring blades, this method improves the mixing speed while also improving the mixing efficiency, which is more conducive to the recovery and treatment of the N-methylaniline residual liquid.

[0029] 3. The longitudinal mixing flow component and the transverse mixing flow channel provided by the present invention can achieve two mixing flow effects through one motor, thereby reducing the investment in power equipment and saving the production cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 It is a schematic diagram of the position of the coil of the present invention.

[0032] Figure 3 It is a schematic diagram of the structure of the coiled tube of the present invention.

[0033] Figure 4 It is a schematic structural diagram of the first connecting sleeve of the present invention.

[0034] Figure 5 It is a schematic diagram of the structure of the nozzle of the present invention.

[0035] Figure 6 It is a structural schematic diagram of the ring tube of the present invention.

[0036] Figure 7 It is a schematic diagram of the structure of a flow-through sleeve at the uppermost end of the present invention.

[0037] Figure 8 It is a schematic diagram of the structure of the flow sleeves except the flow sleeve at the uppermost end of the present invention.

[0038] Fig. 9 It is a structural schematic diagram of the auger of the present invention;

[0039] Fig.10 It is a schematic structural diagram of the active bevel gear of the present invention.

[0040] Figure numerals: 1, kettle body; 2, top cover; 3, filling port; 4, coil; 5, flow sleeve; 6, first spoiler inlet; 7, first spoiler outlet; 8, first cover plate; 9, second cover plate; 10, driven shaft; 11, driving shaft; 12, motor; 13, auger; 14, first connecting sleeve; 15, connecting column; 16, second connecting sleeve; 17, second spoiler inlet; 18, third cover plate; 19, spoiler tube; 20, avoidance space; 21, fourth cover plate; 22, filling pipe; 23, nozzle; 24, annular pipe; 25, valve body; 26, reinforcement ring; 27, active bevel gear ring; 28, driven bevel gear ring; 29, elbow; 30, blade. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0042] For example, see Figures 1 to 10 , This embodiment provides an N-methylaniline residual liquid recovery device, including a kettle body 1, a top cover 2 is fixed at the top opening of the kettle body 1 by bolts, and two filling ports 3 are symmetrically formed on the top cover 2. The residual liquid is filled into the kettle body 1 through one of the filling ports 3, and then the filling port 3 is closed, and the other filling port 3 is connected to a vacuum pumping device, and the vacuum pumping device is used to vacuum the kettle body 1. A coil 4 is fixed on the top cover 2, and both ends of the coil 4 extend above the top cover 2. The main part of the coil 4 extends to the inside of the kettle body 1, one end of the coil 4 is connected to the liquid outlet end of the heat medium circulation system, and the other end of the coil 4 is connected to the liquid inlet end of the heat medium circulation system. When the residual liquid is filled into the kettle body 1 and the preparation work is completed, when the residual liquid inside the kettle body 1 is heated, the heat medium circulation system is used to introduce heat medium into the coil 4, and the residual liquid is heated by the heat medium to perform distillation work, and a discharge port is provided at the bottom of the kettle body 1. The discharge port is opened after the distillation is completed, and the distillation residual liquid is discharged from the discharge port;

[0043] A flow channel composed of a plurality of flow sleeves 5 fixed in sequence from top to bottom is arranged at the center of the inner cavity of the kettle body 1. Both ends of the flow sleeve 5 at the top are sealed, and the flow sleeve 5 at the top is fixed to the center of the bottom surface of the top cover 2. The other flow sleeves 5 are opened at the top and closed at the bottom. When assembling the flow channel, the flow sleeve 5 at the top is first fixed to the bottom surface of the top cover 2, and then the other flow sleeves 5 are fixed in sequence.

[0044] A first flow disturbance inlet 6 in a semicircular shape is symmetrically provided at the bottom of the flow through sleeve 5 , and a first flow disturbance outlet 7 in a semicircular shape is symmetrically provided at the top of the flow through sleeve 5 at the uppermost end;

[0045] The inner walls of all the through-flow sleeves 5 are rotatably connected to the first cover plate 8 at the positions corresponding to the first spoiler inlet 6 through the first torsion hinge, and the top surface of the through-flow sleeve 5 at the uppermost end is directly opposite to the first spoiler outlet 7, and is rotatably connected to the second cover plate 9 through the second torsion hinge. When the residual liquid is driven to be pumped from bottom to top in the flow channel, the residual liquid can push open the first cover plate 8 and the second cover plate 9, so that the first cover plate 8 and the second cover plate 9 are turned upward to open the first spoiler inlet 6 and the first spoiler outlet 7, thereby providing a channel for the residual liquid to flow from the lower part of the inner cavity of the kettle body 1 to the upper part. When the residual liquid is in a state of no action driving the flow in the kettle body 1, or flows from top to bottom, the first cover plate 8 and the second cover plate 9 will not be opened, but will be tightly covered on the inner wall of the through-flow sleeve 5 and the top surface of the through-flow sleeve 5 respectively under the action of the torsion hinge, so as to block the first spoiler outlet 7 and the first spoiler inlet 6.

[0046] A driven shaft 10 is rotatably connected to the axial position of the through-flow sleeve 5 through a bearing. The upper end of the driven shaft 10 on the uppermost through-flow sleeve 5 extends through its top to above it. A driving shaft 11 is rotatably connected to the center position of the top cover 2 through a bearing. The upper end of the driving shaft 11 extends to the top of the top cover 2 and is connected to the output end of the motor 12. The motor 12 is fixed to the top surface of the top cover 2. An auger 13 is fixed to the middle of the outer wall of the driven shaft 10. Each auger 13 is located in the middle position of the corresponding through-flow sleeve 5 inner cavity. The driving shaft 11 and the ends of several driven shafts 10 are connected in pairs. The driving shaft 11 and several driven shafts 10 constitute a transmission shaft. In summary, the structure is that when the residual liquid is heated to the set temperature, the upper When steam is discharged, the driving motor 12 rotates, thereby causing the transmission shaft to rotate, so that the auger 13 at the middle of the inner side of each flow sleeve 5 rotates. When the auger 13 rotates, the residual liquid at the lower part of the flow sleeve 5 is transported to the upper part of the flow sleeve 5 under the action of the auger 13, and thus a negative pressure is formed at the lower part of the flow sleeve 5, forcing the first cover plate 8 inside the flow sleeve 5 to flip upward and open. The residual liquid reaches the upper part of the flow sleeve 5, and continues to be transported to the upper flow sleeve 5 under the transport of the auger 13, pushing the first cover plate 8 at the bottom of the inner wall of the upper flow sleeve 5 to open. In this way, the residual liquid is transported from the lower layer of the inner cavity of the kettle body 1 to the upper layer of the inner cavity of the kettle body 1 through multiple flow sleeves 5 in sequence, thereby achieving the effect of residual liquid convection between the upper and lower layers.

[0047] A first connecting sleeve 14 is formed at the bottom of the driving rotating shaft 11, and a connecting column 15 is formed at the top of the driven rotating shaft 10. The bottom of the driven rotating shaft 10 passes through the flow sleeve 5 and extends to the bottom of the flow sleeve 5 to form a second connecting sleeve 16. The cross-section of the inner cavity of the second connecting sleeve 16 and the cross-section of the inner cavity of the first connecting sleeve 14 are both regular hexagonal. The cross-section of the connecting column 15 is also regular hexagonal. The connecting column 15 at the top of the driven rotating shaft 10 at the top is plugged into the first connecting sleeve 14. Except for the flow sleeve 5 at the top, the connecting columns 15 in all other flow sleeves 5 are located in the inner cavity of the flow sleeve 5. The connecting column 15 between two adjacent driven rotating shafts 10 is plugged into the second connecting sleeve 16.

[0048] When installing the device, when the topmost through-flow sleeve 5 is installed on the top cover 2, the first connecting sleeve 14 is sleeved outside the connecting column 15 on the top of the driven rotating shaft 10 in the middle of the through-flow sleeve 5, and then the through-flow sleeve 5 and the top cover 2 are fixed to realize the connection between the driving rotating shaft 11 and the driven rotating shaft 10;

[0049] When the subsequent flow sleeves 5 are fixedly installed in sequence, the connecting column 15 on the flow sleeve 5 at the lower end is always inserted into the second connecting sleeve 16 on the flow sleeve 5 at the upper end, so that the fixing work of the flow sleeve 5 is completed and the connection work between the driving shaft 11 and the multiple driven shafts 10 is completed. After the connection is completed, the driving shaft 11 rotates so that the multiple driven shafts 10 can rotate at the same time, completing the effect of driving the auger 13 to rotate;

[0050] A plurality of second spoiler inlets 17 are distributed in a circular array on the side wall of the upper end of the flow sleeve 5 with the axis of the flow sleeve 5 as the center. A third cover plate 18 is rotatably connected to the position corresponding to the second spoiler inlet 17 on the inner wall of the flow sleeve 5 through a third torsion hinge. Under the action of the third torsion hinge, the third cover plate 18 covers the second spoiler inlet 17, and the flipping direction of the third cover plate 18 is downward flipping. In this design, when the auger 13 rotates and the residual liquid in the lower part of the flow sleeve 5 is transported to the upper part of the flow sleeve 5 to realize the process of transporting the residual liquid in the entire flow channel from bottom to top, the third cover plate 18 will not be opened. The third torsion hinge makes the third cover plate 18 close the second spoiler inlet 17. At the same time, residual liquid is continuously transported from the upper part of the flow sleeve 5, which will also make the third cover plate 18 tend to more tightly block the second spoiler inlet 17, so as to ensure the smooth realization of the residual liquid convection work in the upper and lower layers of the kettle body 1.

[0051] A plurality of spoiler tubes 19 are installed on the side wall of the lower end of the flow sleeve 5 in the form of a circular array with the axis of the flow sleeve 5 as the center. The spoiler tube 19 is rotatably connected to the side wall of the flow sleeve 5 through a bearing, and the spoiler tube 19 is arranged horizontally. The inner cavity of the spoiler tube 19 is connected to the inner cavity of the flow sleeve 5. A plurality of second spoiler inlets 17 and a plurality of spoiler tubes 19 are staggered in the longitudinal direction, that is, each second spoiler inlet 17 is opposite to the interval between two adjacent spoiler tubes 19, and each spoiler tube 19 is opposite to the interval between two adjacent second spoiler inlets 17, and the spoiler tube 19 and the second spoiler inlet 17 on each flow sleeve 5 are respectively located below and above the auger 13 in the flow sleeve 5;

[0052] The coil 4 is provided with an escape space 20 corresponding to the position of each layer of spoiler tube 19 from top to bottom. One end of the spoiler tube 19 away from the flow-through sleeve 5 extends from the escape space 20 to the outer circle of the coil 4. One end of the spoiler tube 19 away from the flow-through sleeve 5 is rotatably connected to a fourth cover plate 21 through a fourth torsion hinge. The fourth cover plate 21 is tightly covered on the end of the spoiler tube 19 under the action of the fourth torsion hinge.

[0053] The coiled tube 4 is formed by splicing a plurality of parts from top to bottom, and each avoidance space 20 is the connection between two adjacent parts of the coiled tube 4, that is, the gap between two adjacent parts of the coiled tube 4. Thus, when installing the through-flow sleeve 5, after each layer of through-flow sleeve 5 is installed from top to bottom, a part of the coiled tube 4 of the corresponding layer is installed at the same time, and one layer of through-flow sleeve 5 and one layer of part of the coiled tube 4 are installed in sequence. Finally, the flow channel is assembled, and the entire coiled tube 4 is also assembled, and the connection between the various parts of the coiled tube 4 is connected by flanges.

[0054] Similarly, when the auger 13 rotates, the residual liquid in the lower part of the flow sleeve 5 is transported to the upper part of the flow sleeve 5, and the residual liquid in the entire flow channel is transported from bottom to top. Since the residual liquid in the lower part of the flow sleeve 5 is transported upward, the lower part of the flow sleeve 5 has a negative pressure, and the negative pressure forces the first cover plate 8 in the flow sleeve 5 to open. However, since the fourth cover plate 21 is opened outward and the spoiler tube 19 is connected to the lower part of the flow sleeve 5, it also has a negative pressure. At the same time, under the action of the fourth torsion hinge, the fourth cover plate 21 cannot be opened, but the end of the spoiler tube 19 is tightly closed. In this way, when the upper and lower layers of residual liquid are convective, the residual liquid can only pass through the multiple first spoiler inlets 6 in sequence to reach the first spoiler outlet 7 at the upper end for discharge, and cannot be discharged from the second spoiler inlet 17 and the end opening of the spoiler tube 19 in the middle.

[0055] To achieve convection of the residual liquid in the upper and lower layers, the auger 13 provides upward power for the light components in the lower layer, so that they can reach the upper layer faster, accelerating the separation of the light components. At the same time, due to the accelerated separation of the light components, the probability of remixing of the light components with the waste liquid is reduced;

[0056] A plurality of filling pipes 22 are fixed on the top cover 2 in a circular array with the center of the top surface of the top cover 2 as the center. The lower ends of the filling pipes 22 extend into the inner cavity of the kettle body 1. Each filling pipe 22 is located in the interval between two adjacent spoiler tubes 19. A plurality of nozzles 23 are fixed on the filling pipes 22 in sequence from top to bottom. Each nozzle 23 faces a second spoiler inlet 17. The upper ends of the plurality of filling pipes 22 extend to the top of the kettle body 1 and are connected to an annular pipe 24. A valve body 25 is provided at the inlet of the annular pipe 24.

[0057] When the residual liquid in the inner circle of the coil 4 and the residual liquid in the outer circle of the coil 4 form convection, the rotation direction of the motor 12 is opposite to that in the above process. In this way, the effect of the auger 13 being driven to rotate is opposite to that in the above process, that is, the residual liquid in the upper inner part of the flow sleeve 5 is transported to the lower inner part of the flow sleeve 5. In this process, negative pressure occurs in the upper inner part of the flow sleeve 5, so that the first cover plate 8 of the inner wall of the top flow sleeve 5 tends to be closed. Combined with the effect of the first torsion hinge, the first cover plate 8 on the top of the flow sleeve 5 is closed, and positive pressure occurs in the lower inner part of the flow sleeve 5, so that the first cover plate 8 inside the flow sleeve 5 is closed, so that the two end openings of the flow sleeve 5 are blocked. However, since the upper inner part of the flow sleeve 5 has negative pressure, the third cover plate 1 8 overcomes the elastic force of the third torsion spring and flips downward to open, opening the second spoiler inlet 17, and positive pressure appears at the lower inner part of the flow-through sleeve 5, pushing the fourth cover plate 21 at the end of the spoiler tube 19 to overcome the elastic force of the fourth torsion spring and open. Since the end of the spoiler tube 19 extends to the outer ring of the coil 4, the residual liquid in the inner ring of the coil 4 is transported to the outer ring of the coil 4, thereby achieving mixed flow of the residual liquid in the inner and outer rings of the coil 4, and this convection is carried out at multiple positions inside the kettle body 1. Compared with lifting the residual liquid in the lower layer to the uppermost layer for mixed flow, this mixed flow residual liquid has a faster mixing speed. Compared with the traditional technical solution, in which the axial stirring method is centered on the axis of the kettle body 1, the residual liquid convection in the inner and outer rings of the coil 4 can make the residual liquid heat more evenly and faster, greatly improving the processing efficiency of the recovery device.

[0058] For this process, in addition to running during the process of starting to evacuate the kettle body 1 and heating the residual liquid, it can also run while adding strong alkaline water after the residual liquid is added to the kettle body 1. At this time, the operation process is that the residual liquid in the inner and outer circles of the coil 4 are mixed at the upper and lower multi-layer positions, and at the same time, the outlet of the strong alkaline water pumping equipment is connected to the inlet of the ring pipe 24, and the valve is opened. At this time, the kettle body 1 is not in a vacuum state, and strong alkaline water is pumped into each filling pipe 22. When the pressure in each filling pipe 22 reaches the pressure that forces the nozzle 23 to open, the strong alkaline water is sprayed to the second disturbance flow inlet 17 through the nozzle 23. In the process of the residual liquid in the inner and outer circles of the coil 4 undergoing convection mixing, the residual liquid at the center of the coil 4 continuously enters from the second disturbance flow inlet 17, and strong alkaline water is added at the same time in this process, so that the residual liquid in the kettle body 1 can be continuously and evenly mixed with the strong alkaline water. Compared with the traditional stirring form, this form of adding and mixing strong alkaline water greatly improves the mixing speed and uniformity.

[0059] Based on the above, a reinforcing ring 26 is fixed on the outer wall of the flow-through sleeve 5, and the reinforcing ring 26 is sleeved on the outer side of the spoiler tube 19, thereby improving the stability of the connection between the spoiler tube 19 and the flow-through sleeve 5. A plurality of active bevel gear rings 27 are fixed on the transmission shaft from top to bottom, and each active bevel gear ring 27 is opposite to a layer of spoiler tube 19. A driven bevel gear ring 28 is fixed on the outer wall of the spoiler tube 19 close to one end of the active bevel gear ring 27, and the driven bevel gear ring 28 is meshed and connected with the active bevel gear ring 27. The spoiler tube 19 includes an elbow 29 formed at an end thereof away from the flow-through sleeve 5 and bent 90 degrees. The end of the elbow 29 is flat, and the fourth cover plate 21 is rotatably connected to the end of the elbow 29 through a fourth torsion hinge. The fourth cover plate 21 covers the opening at the end of the elbow 29, and a plurality of blades 30 are fixed at equal angles on the outer wall of the spoiler tube 19 close to one end of the elbow 29.

[0060] During the process of adding strong alkaline water, in order to achieve the convection mixing effect of the residual liquid in the inner and outer rings of the coil 4, the driven shaft 10 is continuously rotating, so that the active bevel gear ring 27 continuously drives the multiple driven bevel gear rings 28 on the outside to rotate, thereby causing the multiple spoiler tubes 19 to rotate at the same time. The design of the elbow 29 at the end of the spoiler tube 19 allows the residual liquid mixed with the strong alkaline water to be sprayed and mixed 360 degrees at the end of the spoiler tube 19. At the same time, the spoiler tube 19 is driven to rotate, and the blades 30 drive the strong alkaline water at its end to further mix with the residual liquid, thereby further improving the speed and effect of the strong alkaline water mixing. During the heating process, it is also beneficial for the waste liquid in the inner ring of the coil 4 to be evenly mixed in the waste liquid in the outer ring of the coil 4.

[0061] Embodiment 2, this embodiment provides a N-methylaniline residual liquid distillation recovery process based on embodiment 1, specifically comprising the following steps:

[0062] S1, adding N-methylaniline residual liquid into kettle body 1;

[0063] S2, adding strong alkaline water to the N-methylaniline residual liquid to make the pH of the residual liquid reach 10-12, and performing a hydrolysis reaction. During the hydrolysis reaction, a heat medium is introduced into the coil 4, and the residual liquid is heated while the hydrolysis is performed, and the temperature is maintained at 70-100°C;

[0064] S3, after the hydrolysis reaction is completed, the kettle 1 is evacuated to a predetermined vacuum degree, the vacuum degree is maintained at 10-20 KPa, the temperature is controlled at 140-162°C, and distillation is performed to separate light and heavy components;

[0065] S4. The distillate is sent to the finished product distillation tower for further distillation and purification, and the remaining distillation residue is sent to the distillation residue tank.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A N-methylaniline residual liquid recovery device, comprising a kettle body (1), a coil (4) being fixed on a top cover (2) of the kettle body (1), characterized in that: It also includes a flow channel arranged at the center of the inner cavity of the kettle body (1), and the flow channel is arranged vertically; The inner cavity of the flow channel is provided with a longitudinal mixing flow component, and the inner cavity of the flow channel is composed of a plurality of independent chambers distributed in sequence from top to bottom, and a transverse mixing flow channel connecting the inner circle and the outer circle of the coil (4) is formed on the side wall of each independent chamber; The longitudinal mixing flow assembly has two working states, one of which is to close the inlet and outlet of the transverse mixing flow channel, open the top and bottom of the flow channel, and connect the multiple independent chambers, so that the residual liquid in the lower layer of the inner cavity of the kettle body (1) is transported through the flow channel to the upper layer of the inner cavity of the kettle body (1); Another working state of the longitudinal mixing flow component is to isolate the adjacent independent chambers so that the residual liquid in the inner and outer circles of the coil (4) enters and exits the independent chambers through the inlet and outlet of the transverse mixing flow channel to achieve convection; The flow channel is composed of a plurality of flow sleeves (5) fixed in sequence from top to bottom, the two ends of the flow sleeve (5) at the top are sealed, and the flow sleeve (5) at the top is fixed to the center of the bottom surface of the top cover (2), and the remaining flow sleeves (5) are all opened at the top and closed at the bottom; A first flow disturbance inlet (6) in the form of a semicircle is symmetrically provided at the bottom of the through-flow sleeve (5), and a first flow disturbance outlet (7) in the form of a semicircle is symmetrically provided at the top of the through-flow sleeve (5) at the uppermost end; A first cover plate (8) is rotatably connected to the inner wall of the flow-through sleeve (5) at a position corresponding to the first spoiler inlet (6) via a first torsion hinge, and a second cover plate (9) is rotatably connected to the top surface of the flow-through sleeve (5) at the top end facing the first spoiler outlet (7) via a second torsion hinge; The longitudinal mixed flow assembly comprises a transmission shaft rotatably connected to the axial position of a plurality of flow-through sleeves (5) via a bearing, the upper end of the transmission shaft being rotatably connected to the center position of the top cover (2) via a bearing, the upper end of the transmission shaft passing through the top cover (2) extending to the top of the top cover (2), a motor (12) being fixed at the center of the top surface of the top cover (2), and the upper end of the transmission shaft being fixed to the output end of the motor (12); A auger (13) is provided in the middle of each flow-through sleeve (5), and each auger (13) is wound around and fixed on the outer wall of the transmission shaft at a corresponding position.

2. The N-methylaniline residual liquid recovery device according to claim 1, characterized in that: The transverse mixed flow channel comprises a plurality of second spoiler inlets (17) distributed in a circular array on the upper side wall of the flow sleeve (5) with the axis of the flow sleeve (5) as the center, and a third cover plate (18) is rotatably connected to the position of the inner wall of the flow sleeve (5) corresponding to the second spoiler inlet (17) via a third torsion hinge, and the flipping direction of the third cover plate (18) is downward flipping; The invention also comprises a plurality of spoiler tubes (19) distributed in a circular array on the side wall of the lower end of the flow sleeve (5) with the axis of the flow sleeve (5) as the center. The spoiler tubes (19) are arranged in a transverse direction, and one end of the spoiler tube (19) away from the flow sleeve (5) extends over the coiled tube (4) toward the outer circle of the coiled tube (4). The one end of the spoiler tube (19) away from the flow sleeve (5) is rotatably connected to a fourth cover plate (21) via a fourth torsion hinge.

3. The N-methylaniline residual liquid recovery device according to claim 2, characterized in that: The plurality of second spoiler inlets (17) and the plurality of spoiler tubes (19) are distributed in a staggered manner in the longitudinal direction.

4. The N-methylaniline residual liquid recovery device according to claim 2, characterized in that: The snake tube (4) is provided with avoidance spaces (20) at positions corresponding to each layer of spoiler tubes (19) from top to bottom, and the avoidance spaces (20) are provided for the spoiler tubes (19) to pass over the snake tube (4).

5. The N-methylaniline residual liquid recovery device according to claim 2, characterized in that: The spoiler tube (19) is rotatably connected to the side wall of the flow-through sleeve (5) via a bearing; a plurality of active bevel gear rings (27) are fixed on the transmission shaft in sequence from top to bottom, each active bevel gear ring (27) directly facing a layer of the spoiler tube (19); a driven bevel gear ring (28) is fixed on the outer wall of the spoiler tube (19) at one end close to the active bevel gear ring (27); the driven bevel gear ring (28) is meshingly connected with the active bevel gear ring (27); the spoiler tube (19) comprises an elbow portion (29) formed at one end thereof away from the flow-through sleeve (5) and bent at 90 degrees; the end of the elbow portion (29) is flat, and the fourth cover plate (21) is rotatably connected to the end of the elbow portion (29) via a fourth torsion hinge; a plurality of blades (30) are fixed at equal angles on the outer wall of the spoiler tube (19) at one end close to the elbow portion (29) 6. The N-methylaniline residual liquid recovery device according to claim 5, characterized in that: A plurality of filling pipes (22) are fixed on the top cover (2) in a circular array with the center of the top surface of the top cover (2) as the center, the lower ends of the filling pipes (22) extend into the inner cavity of the kettle body (1), each filling pipe (22) is located in the interval between two adjacent flow disturbance cylinders (19), a plurality of nozzles (23) are fixed on the filling pipe (22) in sequence from top to bottom, each nozzle (23) faces a second flow disturbance inlet (17), the upper ends of the plurality of filling pipes (22) extend to the top of the kettle body (1) and are connected to an annular pipe (24), and a valve body (25) is provided at the inlet of the annular pipe (24).

7. A process for distilling and recovering N-methylaniline residue, characterized in that: The N-methylaniline residual liquid recovery device according to any one of claims 1 to 6 specifically comprises the following steps: S1, adding the residual liquid of N-methylaniline into the kettle (1); S2, adding strong alkaline water to the residual liquid of N-methylaniline to make the pH of the residual liquid reach 10-12, and carrying out a hydrolysis reaction. During the hydrolysis reaction, a heat medium is introduced into the coil (4), and the residual liquid is heated while the hydrolysis is carried out, and the temperature is maintained at 70-100°C; S3. After the hydrolysis reaction is completed, the kettle body (1) is evacuated to a predetermined vacuum degree, the vacuum degree is maintained at 10-20 KPa, the temperature is controlled at 140-162° C., and distillation is performed to separate light and heavy components; S4. The distillate is sent to the finished product distillation tower for further distillation and purification, and the remaining distillation residue is sent to the distillation residue tank.

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