A NMP distillation device

Abstract

The invention provides an NMP distillation device, which relates to the technical field of NMP production equipment. The device comprises a main distillation tower shell, a plurality of tower plates arranged inside the main distillation tower shell and a downcomer arranged on the surface of the tower plates. A dehydration distillation tower and a post-treatment tower are arranged on both sides of the main distillation tower shell, and a reboiler, a cooling device, a tower kettle, an impurity separation device, an online analyzer and a waste liquid collection tank are connected through pipelines. The device also comprises: a plurality of liquid drawing rope bodies are arranged inside the main distillation tower shell; a constraint disc and an extrusion cam are arranged on the surface of the liquid drawing rope body; a driving wheel is arranged on the surface of the liquid drawing rope body; a first regulating wheel, a second regulating wheel and a third regulating wheel are arranged on the surface of the liquid drawing rope body; the invention can adjust the thickness of the liquid phase on the surface of the tower plate through the arrangement of the liquid drawing rope body, reduce the occurrence of gas flooding and liquid flooding, and further adjust the mass transfer efficiency inside the tower plate, and prolong the cleaning time of the tower plate through the adsorption of impurities in the gas phase and liquid phase mass transfer process by the liquid drawing rope body.

Description

Technical Field

[0001] The invention relates to the technical field of NMP production equipment, in particular to an NMP distillation device. Background Art

[0002] NMP is the abbreviation of N-methylpyrrolidone, which is a colorless to light yellow transparent polar oily liquid with a slight ammonia smell. It has the characteristics of high boiling point, low viscosity, good stability, non-corrosiveness, low toxicity and strong solubility. It is mostly used in conductive slurries and lithium-ion batteries.

[0003] The existing NMP recovery method often uses a three-tower distillation process to recover NMP, which is convenient for obtaining high-purity NMP. Among the dehydration distillation tower, main distillation tower and post-treatment tower in the related process, the main distillation tower needs to be precisely operated under reduced pressure conditions to avoid NMP decomposition. At the same time, the reflux ratio and temperature gradient need to be adjusted. It undertakes the task of completely separating NMP from water and volatile impurities, which is the most important step in the three-tower system.

[0004] In the existing three-tower NMP distillation process, the main distillation tower is prone to flooding, gas flooding and plate blockage during operation, resulting in reduced mass transfer efficiency and fluctuations in product purity. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an NMP distillation device. By setting a liquid-drawing rope body, the thickness of the liquid phase on the surface of the tower plate can be regulated, and then the mass transfer efficiency inside the tower plate can be regulated. By adsorbing impurities in the gas phase and liquid phase mass transfer process by the liquid-drawing rope body, the cleaning time of the tower plate can be extended, and the distillation efficiency of NMP can be improved.

[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0007] An NMP distillation device comprises a main distillation tower shell, a plurality of tower plates arranged inside the main distillation tower shell, and a downcomer arranged on the surface of the tower plates, a dehydration distillation tower and a post-treatment tower are arranged on both sides of the main distillation tower shell, and a reboiler, a cooling device, a tower kettle, an impurity separation device, an online analyzer and a waste liquid collection tank are connected through pipelines, and also comprises:

[0008] A plurality of liquid-drawing ropes are arranged inside the main distillation tower shell, and the liquid-drawing ropes are used to adjust the liquid level thickness on the surface of each of the tower plates, thereby increasing the contact area between the gas phase and the liquid phase inside the main distillation tower shell;

[0009] The surface of the liquid-drawing rope body is provided with a constraining disc and an extrusion cam, which is used to extrude the liquid-phase NMP absorbed inside the liquid-drawing rope body through the convex portion of the extrusion cam surface cooperating with the constraining disc;

[0010] A driving wheel is provided on the surface of the liquid-drawing rope body, and the driving wheel is used to drive the liquid-drawing rope body to complete a circular rotation inside the main distillation tower shell, so as to drive the change of the liquid phase thickness on the surface of each of the tower plates, and at the same time regulate the contact time between the liquid phase NMP adsorbed by the liquid-drawing rope body and the gas phase;

[0011] The surface of the liquid-drawing rope body is provided with a first adjusting wheel, a second adjusting wheel and a third adjusting wheel for adjusting the tension of the liquid-drawing rope body, and by adjusting the positional relationship between the second adjusting wheel and the third adjusting wheel, the liquid-drawing rope body is rotated or stopped inside the main distillation tower shell.

[0012] Furthermore, an operation box is fixedly connected to the reserved groove on the surface of the main distillation tower shell, a sealing cover is installed on the surface of the operation box, the liquid drawing rope body is arranged inside the operation box and extends to the inside of the main distillation tower shell, a plurality of through holes are evenly opened on the surface of the tower plate near the inner wall of the main distillation tower shell, a guide elbow is arranged above the through holes, the guide elbow is fixedly connected to the corresponding tower plate, the liquid drawing rope body passes through the surface of each tower plate in turn through the through holes and the guide elbow, the guide elbow and the tower plate are both slidably connected to the liquid drawing rope body, a plurality of isolation grooves are protrudingly provided on the inner wall of the main distillation tower shell, the liquid drawing rope body passes through the isolation groove from bottom to top and is slidably connected to the isolation groove.

[0013] Furthermore, a driving motor is installed on the surface of the operating box, and a first round rod is arranged inside the operating box. The first round rod is rotatably connected to a corresponding first through groove opened on the inner wall of the operating box through two first bearings, and the driving motor output shaft is fixedly connected to the driving motor. A plurality of driving wheels are fixedly connected to the surface of the first round rod, and the liquid-drawing rope body fits in a groove on the surface of the driving wheel.

[0014] Furthermore, a plurality of second round rods are provided inside the operation box, the second round rods are fixedly connected to the inner wall of the operation box, a third round rod is provided above the second round rod, the third round rod is fixedly connected to the inner wall of the operation box, a plurality of groups of constraint discs are provided on the surface of the second round rod, the constraint discs are rotatably connected to the second round rods through first bearings, a plurality of extrusion cams are provided on the surface of the third round rod, the extrusion cams are rotatably connected to the third round rods through third bearings, each group of the constraint discs are symmetrically arranged on both sides of the corresponding extrusion cams, and each of the liquid-drawing ropes is passed between the corresponding extrusion cam and a corresponding group of the constraint discs.

[0015] Furthermore, an electric telescopic cylinder is provided on one side of the driving wheel, and the electric telescopic cylinder is installed on the inner bottom surface of the operating box. The first adjusting wheel and the second adjusting wheel are both fitted with the liquid-absorbing rope body through grooves opened on the surface. Second mounting strips are provided on both sides of the first adjusting wheel and the second adjusting wheel. The first adjusting wheel is rotatably connected to the second mounting strip through two fourth bearings, and the second adjusting wheel is rotatably connected to the second mounting strip through two first one-way bearings. The end of the output shaft of the electric telescopic cylinder is fixedly connected to the surface of one of the second mounting strips, and a pressure sensor is installed at the connection between the electric telescopic cylinder and the second mounting strip. The third adjusting wheel is located directly below the second adjusting wheel, and third mounting strips are provided on both sides of the third adjusting wheel. The third mounting strip is fixedly connected to the operating box, and the third adjusting wheel is rotatably connected to the third mounting strip through two second one-way bearings.

[0016] Furthermore, the surfaces of the first adjusting wheel, the second adjusting wheel and the third adjusting wheel are all provided with corresponding teeth, the first adjusting wheel is meshedly connected with the second adjusting wheel, the second adjusting wheel is meshedly connected with the third adjusting wheel, and the second adjusting wheel and the third adjusting wheel are arranged in opposite rotation directions.

[0017] Furthermore, the operating box is internally fixedly connected with two fixing bars, which are symmetrically arranged on both sides of the first adjusting wheel. The fixing bar and the first adjusting wheel are provided with two groups of first constraint wheels on both sides, and each group of the first constraint wheels is provided on the upper and lower sides of the liquid-drawing rope body. The first constraint wheels are fitted with the liquid-drawing rope body through grooves opened on the surface. First mounting bars are provided on both sides of each group of the first constraint wheels, and the first mounting bars are fixedly connected to the corresponding fixing bars. The first constraint wheels are rotatably connected to the corresponding two first mounting bars through two fifth bearings.

[0018] Furthermore, the liquid-drawing rope body includes an outer rope loop located on the outside, the surface of the outer rope loop is hollow, and a plurality of driving spheres are equidistantly fixedly connected to the inside of the outer rope loop. A liquid-drawing inner core is arranged on the inner side of the liquid-drawing rope body, and the liquid-drawing inner core is located in a through hole opened on the surface of the driving sphere and is slidably connected to the driving sphere. A plurality of curved grooves are opened in a circular array in the groove opened on the surface of the driving wheel, and the curved groove corresponds to the driving wheel.

[0019] Furthermore, the two ends of the liquid-absorbing rope body are fixedly connected in the following manner: one end of the outer rope loop is fixedly connected to a lower connecting part, and the other end of the outer rope loop is fixedly connected to an upper connecting part, a threaded groove is provided on the bottom surface of the upper connecting part, and the lower connecting part is threadedly connected to the upper connecting part via the threaded groove, and the two ends of the liquid-absorbing inner core located inside the outer rope loop are fixedly connected to each other.

[0020] Furthermore, a plurality of accommodating grooves are provided in a circular array inside the upper connecting portion, and a fourth round rod is fixedly connected inside each of the accommodating grooves, and an L-shaped block is rotatably connected to the surface of the fourth round rod.

[0021] The above solution of the present invention includes at least the following beneficial effects:

[0022] According to the above scheme of the present invention, the liquid phase on the surface of the tower plate can be assisted to descend by the liquid drawing rope body that passes through the tower plate in sequence and rotates. At the same time, the liquid drawing rope body rotates, so that the liquid descending efficiency between the tower plates of each layer can be regulated, and the occurrence of liquid flooding and gas flooding can be reduced. At the same time, the liquid drawing rope body can adsorb and store liquid phase NMP, so that the liquid drawing rope body and the gas phase can also undergo a mass transfer process, thereby increasing the mass transfer area between the gas phase and the liquid phase. At the same time, the liquid drawing rope body adsorbs NMP impurities, thereby reducing the risk of tower plate blockage, extending the tower plate cleaning time, and thereby improving the distillation efficiency of NMP. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure provided by the present invention.

[0024] Figure 2 It is a schematic diagram of an operation box in the present invention.

[0025] Figure 3 It is a schematic diagram of the isolation tank body in the present invention.

[0026] Figure 4 It is a schematic diagram of the fixing strip in the present invention.

[0027] Figure 5 It is a schematic diagram of the extrusion cam in the present invention.

[0028] Figure 6 It is a schematic diagram of the installation of the guide elbow in the present invention.

[0029] Figure 7 The present invention Figure 6 Enlarged view of point A in the middle.

[0030] Figure 8 It is a schematic diagram of the installation of the liquid-absorbing inner core in the present invention.

[0031] Fig. 9 It is a schematic diagram of the installation of the L-shaped block in the present invention.

[0032] In the figure: 101, main distillation tower shell; 102, tower plate; 103, downcomer plate;

[0033] 201, operation box; 202, sealing cover; 203, liquid-drawing rope body; 204, through hole; 205, guide elbow; 206, driving motor; 207, first round rod; 208, driving wheel; 209, curved groove; 210, fixing bar; 211, first mounting bar; 212, first restraining wheel; 213, electric telescopic cylinder; 214, second mounting bar; 215, first adjusting wheel; 216, second adjusting wheel; 217, third mounting bar; 218, third adjusting wheel; 219, second round rod; 220, restraining disc; 221, extrusion cam; 222, third round rod; 223, isolation tank body;

[0034] 2031, outer rope loop; 2032, driving ball; 2033, liquid-absorbing inner core; 2034, lower connecting part; 2035, upper connecting part; 2036, receiving groove; 2037, L-shaped block; 2038, fourth round rod; 2039, threaded groove. DETAILED DESCRIPTION

[0035] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0036] like Figure 1 As shown, an embodiment of the present invention provides an NMP distillation device, including a main distillation tower shell 101 and a plurality of tower plates 102 arranged inside the main distillation tower shell 101 and a downcomer 103 arranged on the surface of the tower plate 102, a dehydration distillation tower and a post-treatment tower are arranged on both sides of the main distillation tower shell 101, and a reboiler, a cooling device, a tower kettle, an impurity separation device, an online analyzer and a waste liquid collection tank are connected through pipelines, and also includes:

[0037] A plurality of liquid drawing ropes 203 are arranged inside the main distillation tower shell 101. The liquid drawing ropes 203 are used to adjust the liquid level thickness on the surface of each tower plate 102, thereby increasing the contact area between the gas phase and the liquid phase inside the main distillation tower shell 101.

[0038] The surface of the liquid-drawing rope body 203 is provided with a constraining disc 220 and an extrusion cam 221, which are used to squeeze out the liquid-phase NMP absorbed inside the liquid-drawing rope body 203 through the convex portion on the surface of the extrusion cam 221 cooperating with the constraining disc 220;

[0039] A driving wheel 208 is provided on the surface of the liquid-drawing rope 203, and the driving wheel 208 is used to drive the liquid-drawing rope 203 to complete a circular rotation inside the main distillation tower shell 101, so as to drive the liquid phase thickness on the surface of each tower plate 102 to change, and at the same time regulate the contact time between the liquid phase NMP adsorbed by the liquid-drawing rope 203 and the gas phase;

[0040] The surface of the liquid-drawing rope 203 is provided with a first adjusting wheel 215, a second adjusting wheel 216 and a third adjusting wheel 218, which are used to adjust the tension of the liquid-drawing rope 203, and by adjusting the positional relationship between the second adjusting wheel 216 and the third adjusting wheel 218, the liquid-drawing rope 203 can be rotated or stopped inside the main distillation tower shell 101.

[0041] In the embodiment of the present invention, the liquid-drawing rope body 203 is arranged in a Z-shape inside the main distillation tower shell 101. When the main distillation tower shell 101 performs distillation, the liquid phase NMP on the surface of the tower plate 102 will be partially absorbed by the liquid-drawing rope body 203, and flows inside the liquid-drawing rope body 203 under the cooperation of capillary action and gravity action, and the gas phase NMP also performs mass transfer exchange through the liquid phase flowing inside the liquid-drawing rope body 203, thereby increasing the mass transfer exchange area between the gas phase and the liquid phase inside the main distillation tower shell 101, and the liquid-drawing rope body 203 on its surface is driven by the rotation of the driving wheel 208. The movement between the plates 102 increases the speed of the liquid phase accumulated on the surface of the plates 102 flowing downward. After the liquid-drawing rope 203 moves from the surface of the top plate 102 to the bottom of the bottom plate 102, the liquid-phase NMP adsorbed inside the liquid-drawing rope 203 is squeezed out by the constraint of the constraint disc 220 and the rolling of the extrusion cam 221. The first regulating wheel 215 and the second regulating wheel 216 move in the vertical direction to change the tension of the liquid-drawing rope 203, so as to improve the transmission effect of the driving wheel 208 on the liquid-drawing rope 203.

[0042] like Figure 1 , Figure 2 and Figure 6As shown, an operation box 201 is fixedly connected in a reserved groove opened on the surface of the main distillation tower shell 101, a sealing cover 202 is installed on the surface of the operation box 201, a liquid drawing rope body 203 is arranged inside the operation box 201 and extends to the inside of the main distillation tower shell 101, a plurality of through holes 204 are evenly opened on the surface of the tower plate 102 near the inner wall of the main distillation tower shell 101, and a guide elbow 205 is arranged above the through holes 204. The guide elbow 205 is fixedly connected to the corresponding tower plate 102, and the liquid drawing rope body 203 passes through the surface of each tower plate 102 in turn through the through holes 204 and the guide elbow 205, and the guide elbow 205 and the tower plate 102 are both slidably connected to the liquid drawing rope body 203, and a plurality of isolation groove bodies 223 are protrudingly provided on the inner wall of the main distillation tower shell 101, and the liquid drawing rope body 203 passes through the isolation groove body 223 from bottom to top and is slidably connected to the isolation groove body 223.

[0043] In the embodiment of the present invention, the components inside the operation box 201 can be inspected, cleaned and replaced by opening the sealing cover 202 on the surface of the operation box 201. The friction between the liquid drawing rope 203 and the tower plate 102 can be reduced by guiding the guide elbow 205 during the process of the liquid drawing rope 203 passing through the through hole 204 on the surface of the tower plate 102. The isolation tank 223 prevents the portion of the liquid drawing rope 203 located inside the isolation tank 223 from exchanging mass transfer with the gas phase inside the main distillation tower shell 101 during the upward movement, and prevents the liquid drawing rope 203 from exchanging mass transfer with the gas phase inside the main distillation tower shell 101. The liquid phase inside the main distillation tower shell 101 is attached. When the liquid-drawing rope body 203 protrudes from the top outlet of the isolation tank body 223 and moves along the Z-shape, it first absorbs the liquid phase on the surface of the upper tower plate 102. In the process of the liquid-drawing rope body 203 penetrating the tower plates 102 one by one and moving downward, in addition to the liquid phase part adsorbed by itself, it will also drive part of the liquid phase close to its surface to move downward during its movement, thereby improving the control effect of the liquid-drawing rope body 203 on the liquid phase thickness on the tower plate 102 surface, and reducing the occurrence of liquid flooding inside the main distillation tower shell 101.

[0044] like Figure 1 , Figure 2 and Figure 4 As shown, a driving motor 206 is installed on the surface of the operating box 201, and a first round rod 207 is arranged inside the operating box 201. The first round rod 207 is rotatably connected to the corresponding first through groove opened on the inner wall of the operating box 201 through two first bearings. The output shaft of the driving motor 206 is fixedly connected to the driving motor 206. A plurality of driving wheels 208 are fixedly connected to the surface of the first round rod 207, and the liquid-drawing rope body 203 fits in the groove on the surface of the driving wheel 208.

[0045] In the embodiment of the present invention, the driving motor 206 is powered on to make the first round rod 207 drive the driving wheel 208 to rotate. The rotation of the driving wheel 208 drives the liquid-absorbing rope 203 attached to its surface to move following the rotation of the driving wheel 208.

[0046] like Figure 4 As shown, a plurality of second round rods 219 are provided inside the operation box 201, and the second round rods 219 are fixedly connected to the inner wall of the operation box 201. A third round rod 222 is provided above the second round rod 219, and the third round rod 222 is fixedly connected to the inner wall of the operation box 201. A plurality of groups of constraining discs 220 are provided on the surface of the second round rod 219, and the constraining discs 220 are rotatably connected to the second round rod 219 through a first bearing. A plurality of squeezing cams 221 are provided on the surface of the third round rod 222, and the squeezing cams 221 are rotatably connected to the third round rod 222 through a third bearing. Each group of constraining discs 220 are symmetrically arranged on both sides of the corresponding squeezing cam 221, and each liquid-drawing rope body 203 is passed between the corresponding squeezing cam 221 and the corresponding group of constraining discs 220.

[0047] In the embodiment of the present invention, during the rotation of the liquid-drawing rope body 203 inside the operating box 201 and the main distillation tower shell 101, the portion of the liquid-drawing rope body 203 located between the constraint disc 220 and the extrusion cam 221, the constraint disc 220 constrains its movement trajectory, so that the portion of the liquid-drawing rope body 203 located below the extrusion cam 221 always moves in a direction perpendicular to the axial direction of the extrusion cam 221. During this process, the movement of the liquid-drawing rope body 203 drives the corresponding extrusion cam 221 on the third round rod 222 to continuously rotate, so that the convex portion of the extrusion cam 221 cooperates with the second round rod 219 located below this section of the liquid-drawing rope body 203 to continuously crush the surface of the liquid-drawing rope body 203, so that the liquid phase adsorbed inside the liquid-drawing rope body 203 is squeezed out, which facilitates the circulation of the liquid phase inside the main distillation tower shell 101.

[0048] like Figure 4 and Figure 5As shown, an electric telescopic cylinder 213 is provided on one side of the driving wheel 208, and the electric telescopic cylinder 213 is installed on the inner bottom surface of the operation box 201. The first adjusting wheel 215 and the second adjusting wheel 216 are both fitted with the liquid-drawing rope body 203 through grooves opened on the surface. Second mounting strips 214 are provided on both sides of the first adjusting wheel 215 and the second adjusting wheel 216. The first adjusting wheel 215 is rotatably connected to the second mounting strip 214 through two fourth bearings, and the second adjusting wheel 216 is rotatably connected to the second mounting strip 214 through two first one-way bearings. 214 is rotatably connected, the end of the output shaft of the electric telescopic cylinder 213 is fixedly connected to the surface of one of the second mounting bars 214, a pressure sensor is installed at the connection between the electric telescopic cylinder 213 and the second mounting bar 214, the third adjusting wheel 218 is located directly below the second adjusting wheel 216, and third mounting bars 217 are arranged on both sides of the third adjusting wheel 218, the third mounting bar 217 is fixedly connected to the operation box 201, and the third adjusting wheel 218 is rotatably connected to the third mounting bar 217 through two second one-way bearings.

[0049] The surfaces of the first adjusting wheel 215, the second adjusting wheel 216 and the third adjusting wheel 218 are all provided with corresponding teeth, the first adjusting wheel 215 is meshedly connected with the second adjusting wheel 216, the second adjusting wheel 216 is meshedly connected with the third adjusting wheel 218, and the second adjusting wheel 216 and the third adjusting wheel 218 are arranged in opposite directions of rotation.

[0050] In the embodiment of the present invention, by regulating the extension and retraction of the electric telescopic cylinder 213, the second mounting bar 214 is controlled to drive the first adjusting wheel 215 and the second adjusting wheel 216 to move in the vertical direction, so that the liquid-drawing rope body 203 is tightened or relaxed, so as to ensure the static friction between the driving wheel 208 and the liquid-drawing rope body 203, so that the driving wheel 208 has a better transmission effect on the liquid-drawing rope body 203. At the same time, the liquid-drawing rope body 203 gradually undergoes irreversible tensile deformation during long-term use, which may cause it to slip during the transmission process on the surface of the driving wheel 208, thereby affecting the liquid-drawing rope body 203 The regulation of the liquid phase thickness on the surface of the tower plate 102 by the liquid-drawing rope body 203, by adjusting the corresponding length of the electric telescopic cylinder 213, in conjunction with the pressure sensor at the end of the electric telescopic cylinder 213, the contact pressure between each liquid-drawing rope body 203 and the driving wheel 208 can be kept consistent, so as to facilitate the liquid-drawing rope 203 to be moved by the driving wheel 208. The body 203 regulates the liquid thickness inside the tower plate 102. When the pressure sensor sensing value at the end of the electric telescopic cylinder 213 is lower than the set value, it can be determined that the corresponding liquid-drawing rope body 203 is disconnected. At this time, the corresponding electric telescopic cylinder 213 can be adjusted to shorten the electric telescopic cylinder 213 until the second adjusting wheel 216 is meshed and connected with the third adjusting wheel 218 on the third mounting bar 217. Because the rotation directions of the second adjusting wheel 216 and the third adjusting wheel 218 are opposite to each other under the constraints of the first one-way bearing and the second one-way bearing, respectively, when the two are meshed and connected, the third adjusting wheel 218 and the second round rod 219 cannot rotate. At this time, the second adjusting wheel 216 and the third adjusting wheel 218 clamp the liquid-drawing rope body 203, causing the liquid-drawing rope body 203 to slip on the surface of the driving wheel 208, thereby making the liquid-drawing rope body 203 unable to be driven by the driving wheel 208.

[0051] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the operation box 201 is internally fixedly connected with two fixing bars 210, which are symmetrically arranged on both sides of the first adjusting wheel 215. The fixing bars 210 and the first adjusting wheel 215 are provided with two groups of first constraint wheels 212 on both sides, and each group of first constraint wheels 212 is provided on the upper and lower sides of the liquid-drawing rope body 203. The first constraint wheels 212 are fitted with the liquid-drawing rope body 203 through grooves opened on the surface. First mounting bars 211 are provided on both sides of each group of first constraint wheels 212, and the first mounting bars 211 are fixedly connected to the corresponding fixing bars 210. The first constraint wheels 212 are rotatably connected to the corresponding two first mounting bars 211 through two fifth bearings.

[0052] In the embodiment of the present invention, by setting the first constraint wheels 212 on both sides of the first adjusting wheel 215, the electric telescopic cylinder 213 controls the second mounting bar 214 to drive the first adjusting wheel 215 and the second adjusting wheel 216 to move in the vertical direction, so that the liquid-drawing rope body 203 is deformed only between the two groups of first constraint wheels 212, thereby preventing the deformation of the liquid-drawing rope body 203 from affecting the contact area between the driving wheel 208 and the liquid-drawing rope body 203. The setting of the fixing bar 210 makes it easy to fix the first constraint wheel 212 through the first mounting bar 211.

[0053] like Figure 4 , Figure 5 and Figure 8 As shown, the liquid-drawing rope body 203 includes an outer rope loop 2031 located on the outside, the surface of the outer rope loop 2031 is hollow, and a plurality of driving spheres 2032 are fixedly connected to the inside of the outer rope loop 2031 at equal intervals. A liquid-drawing inner core 2033 is provided on the inner side of the liquid-drawing rope body 203, and the liquid-drawing inner core 2033 is located in a through hole opened on the surface of the driving sphere 2032 and is slidably connected to the driving sphere 2032. A plurality of curved grooves 209 are opened in a ring array in the groove opened on the surface of the driving wheel 208, and the curved grooves 209 correspond to the driving wheel 208.

[0054] In the embodiment of the present invention, the hollow surface of the outer rope loop 2031 facilitates the liquid-absorbing inner core 2033 located therein to adsorb the liquid phase inside the main distillation tower shell 101, and facilitates the mass transfer process between the gas phase passing through the hollow part and the liquid phase inside the outer rope loop 2031. At the same time, the outer rope loop 2031 protects the liquid-absorbing inner core 2033, reduces the wear of the liquid-absorbing inner core 2033, and allows the liquid-absorbing inner core 2033 to remain relaxed when the outer rope loop 2031 is tightened, thereby maintaining its adsorption and storage properties for the liquid phase and the flow of the liquid phase inside it. The arrangement of the driving ball 2032 increases the stability of the self-rotation of the liquid-drawing rope 203 through the corresponding engagement of the curved groove 209 and the driving ball 2032 during the rotation of the driving wheel 208. The concave portion of the squeezing cam 221 continuously engages with the driving ball 2032, which also ensures that during the self-rotation of the liquid-drawing rope 203, the driving ball 2032 continuously drives the corresponding squeezing cam 221 to rotate, so that the convex portion of the squeezing cam 221 continuously squeezes the portion of the liquid-drawing rope 203 located between two adjacent driving balls 2032.

[0055] like Fig. 9As shown, the two ends of the liquid-absorbing rope body 203 are fixedly connected in the following manner: one end of the outer rope loop 2031 is fixedly connected to the lower connecting part 2034, and the other end of the outer rope loop 2031 is fixedly connected to the upper connecting part 2035. A threaded groove 2039 is provided on the bottom surface of the upper connecting part 2035, and the lower connecting part 2034 is threadedly connected to the upper connecting part 2035 through the threaded groove 2039. The two ends of the liquid-absorbing inner core 2033 located inside the outer rope loop 2031 are fixedly connected to each other.

[0056] In the embodiment of the present invention, when the liquid-drawing rope body 203 needs to be replaced or cleaned, the sealing cover 202 on the surface of the operation box 201 is opened, and the upper connecting portion 2035 is withdrawn from the threaded ring portion of the lower connecting portion 2034, and one end of the liquid-drawing rope body 203 is pulled out of the device. When the liquid-drawing inner core 2033 inside the liquid-drawing rope body 203 needs to be replaced, the upper connecting portion 2035 is separated from the lower connecting portion 2034, and an external tool such as a knife is used to disconnect the liquid-drawing inner core 2033 at the separation point between the two. An external tool such as a clamping device is used to fix the disconnected lower connecting portion 2034 and the upper connecting portion 2035 respectively, and a new liquid-drawing inner core 2033 is inserted. One end of the inner core 2033 is fixedly connected to one end of the old liquid-absorbing inner core 2033, and the other end of the old liquid-absorbing inner core 2033 is pulled out to the outside of the outer rope loop 2031 until the old liquid-absorbing inner core 2033 is completely pulled out of the outer rope loop 2031, the new liquid-absorbing inner core 2033 is disconnected from the old liquid-absorbing inner core 2033, and the two ends of the new liquid-absorbing inner core 2033 are re-fixed and connected, and then the lower connecting part 2034 is re-threaded with the upper connecting part 2035 to complete the replacement. The adsorption of impurities by the liquid-absorbing rope body 203 also reduces the compaction and precipitation of impurities on the surface of the tower plate 102, thereby extending the cleaning time of the tower plate 102.

[0057] like Fig. 9 As shown, a plurality of receiving grooves 2036 are provided in a circular array inside the upper connecting portion 2035 , and a fourth round rod 2038 is fixedly connected inside each of the receiving grooves 2036 , and an L-shaped block 2037 is rotatably connected to the surface of the fourth round rod 2038 .

[0058] In an embodiment of the present invention, during the process of threaded connection between the lower connecting part 2034 and the upper connecting part 2035, the threaded convex ring will push the L-shaped block 2037 on the surface of the fourth round rod 2038, causing the longer part of the L-shaped block 2037 to rotate toward the central axis of the upper connecting part 2035, thereby causing the L-shaped block 2037 to squeeze the liquid-absorbing core 2033 inside the upper connecting part 2035, so that the liquid-absorbing core 2033 and the upper connecting part 2035 remain relatively fixed, so as to avoid a large rotation speed difference between the liquid-absorbing cores 2033 inside different upper connecting parts 2035 when adjusting the rotation speed of the liquid-absorbing rope body 203, thereby affecting the liquid-absorbing rope body 203's control of the liquid phase thickness on the surface of the tower plate 102.

[0059] It should be noted that the installation method, connection relationship and use method between the main distillation tower shell 101, the tower plate 102, the downcomer 103, the dehydration distillation tower, the post-treatment tower, the reboiler, the cooling device, the tower kettle, the impurity separation device, the online analyzer and the waste liquid collection tank are well known in the prior art, and the specific connection method is not shown in the drawings and will not be described in detail here;

[0060] The surface of the lower connecting portion 2034 is provided with a threaded protruding ring, so that the lower connecting portion 2034 and the upper connecting portion 2035 can be threadedly connected through the threaded protruding ring and the thread groove 2039;

[0061] The overall shape of the upper connecting part 2035 and the lower connecting part 2034 after being threadedly connected is the same as the shape of any driving ball 2032, so that the driving wheel 208 can rotate the liquid-drawing rope body 203 through the cooperation between the curved groove 209 and the driving ball 2032;

[0062] The surface of the tower plate 102 is uniformly provided with small holes to facilitate mass transfer between the gas phase and the liquid phase.

[0063] When the tray 102 is assembled inside the main distillation column shell 101, the surface close to the isolation tank body 223 can be avoided by being recessed;

[0064] The material of the liquid-absorbing inner core 2033 has a strong adsorption capacity for liquid-phase NMP, which facilitates the liquid-absorbing rope body 203 to control the thickness of the liquid phase on the surface of the tower plate 102 .

[0065] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A NMP distillation device, characterized in that, The invention comprises a main distillation tower shell (101), a plurality of tower plates (102) arranged inside the main distillation tower shell (101), and a downcomer (103) arranged on the surface of the tower plates (102); a dehydration distillation tower and a post-treatment tower are arranged on both sides of the main distillation tower shell (101), and a reboiler, a cooling device, a tower kettle, an impurity separation device, an online analyzer and a waste liquid collection tank are connected through pipelines; and the invention is characterized in that it also comprises: A plurality of liquid-drawing ropes (203) are arranged inside the main distillation tower shell (101), and the liquid-drawing ropes (203) are used to adjust the liquid level thickness on the surface of each of the tower plates (102) to increase the contact area between the gas phase and the liquid phase inside the main distillation tower shell (101); The surface of the liquid-drawing rope body (203) is provided with a constraining disc (220) and an extrusion cam (221), which is used to extrude the liquid-phase NMP absorbed inside the liquid-drawing rope body (203) through the convex portion on the surface of the extrusion cam (221) in cooperation with the constraining disc (220); A driving wheel (208) is provided on the surface of the liquid-drawing rope body (203), and the driving wheel (208) is used to drive the liquid-drawing rope body (203) to complete a circular rotation inside the main distillation tower shell (101), so as to drive the thickness of the liquid phase on the surface of each of the tower plates (102) to change, and at the same time to adjust the contact time between the liquid phase NMP adsorbed by the liquid-drawing rope body (203) and the gas phase; A first adjusting wheel (215), a second adjusting wheel (216) and a third adjusting wheel (218) are provided on the surface of the liquid-drawing rope body (203) for adjusting the tension of the liquid-drawing rope body (203), and by adjusting the positional relationship between the second adjusting wheel (216) and the third adjusting wheel (218), the liquid-drawing rope body (203) is caused to rotate or stop moving inside the main distillation tower shell (101).

2. The NMP distillation device according to claim 1, characterized in that: An operation box (201) is fixedly connected to a reserved groove on the surface of the main distillation tower shell (101); a sealing cover (202) is installed on the surface of the operation box (201); the liquid-drawing rope (203) is arranged inside the operation box (201) and extends into the interior of the main distillation tower shell (101); a plurality of through holes (204) are evenly arranged on the surface of the tower plate (102) near the inner wall of the main distillation tower shell (101); guide bends (205) are arranged above the through holes (204); and the guide bends (205) are arranged on the surfaces of the tower plates (102). 05) is fixedly connected to the corresponding tower plate (102), the liquid-drawing rope body (203) passes through the surface of each tower plate (102) in sequence through the through hole (204) and the guide bend (205), the guide bend (205) and the tower plate (102) are both slidably connected to the liquid-drawing rope body (203), and a plurality of isolation grooves (223) are protrudingly provided on the inner wall of the main distillation tower shell (101), and the liquid-drawing rope body (203) passes through the isolation grooves (223) from bottom to top and is slidably connected to the isolation grooves (223).

3. The NMP distillation device according to claim 2, characterized in that: A driving motor (206) is mounted on the surface of the operating box (201); a first round rod (207) is arranged inside the operating box (201); the first round rod (207) is rotatably connected to a corresponding first through groove provided on the inner wall of the operating box (201) via two first bearings; an output shaft of the driving motor (206) is fixedly connected to the first round rod (207); a plurality of driving wheels (208) are fixedly connected to the surface of the first round rod (207); and the liquid-drawing rope body (203) fits in a groove on the surface of the driving wheel (208).

4. The NMP distillation device according to claim 3, characterized in that: A plurality of second round rods (219) are arranged inside the operation box (201), the second round rods (219) are fixedly connected to the inner wall of the operation box (201), a third round rod (222) is arranged above the second round rod (219), the third round rod (222) is fixedly connected to the inner wall of the operation box (201), a plurality of groups of constraining round plates (220) are arranged on the surface of the second round rod (219), the constraining round plates (220) are rotatably connected to the second round rod (219) via a first bearing, a plurality of squeezing cams (221) are arranged on the surface of the third round rod (222), the squeezing cams (221) are rotatably connected to the third round rod (222) via a third bearing, each group of the constraining round plates (220) are symmetrically arranged on both sides of the corresponding squeezing cam (221), and each of the liquid-drawing rope bodies (203) is passed between the corresponding squeezing cam (221) and a corresponding group of the constraining round plates (220).

5. The NMP distillation device according to claim 4, characterized in that: An electric telescopic cylinder (213) is provided on one side of the driving wheel (208), and the electric telescopic cylinder (213) is mounted on the inner bottom surface of the operating box (201). The first adjusting wheel (215) and the second adjusting wheel (216) are both fitted with the liquid-drawing rope body (203) via grooves provided on the surface. Second mounting strips (214) are provided on both sides of the first adjusting wheel (215) and the second adjusting wheel (216). The first adjusting wheel (215) is rotatably connected to the second mounting strip (214) via two fourth bearings, and the second adjusting wheel (216) is rotatably connected to the second mounting strip (214) via two first one-way bearings. The electric telescopic cylinder (213) is rotatably connected to the second mounting bar (214), the end of the output shaft of the electric telescopic cylinder (213) is fixedly connected to the surface of one of the second mounting bars (214), a pressure sensor is installed at the connection between the electric telescopic cylinder (213) and the second mounting bar (214), the third adjusting wheel (218) is located directly below the second adjusting wheel (216), third mounting bars (217) are arranged on both sides of the third adjusting wheel (218), the third mounting bar (217) is fixedly connected to the operation box (201), and the third adjusting wheel (218) is rotatably connected to the third mounting bar (217) via two second one-way bearings.

6. The NMP distillation device according to claim 5, characterized in that: The surfaces of the first adjusting wheel (215), the second adjusting wheel (216) and the third adjusting wheel (218) are all provided with corresponding teeth; the first adjusting wheel (215) is meshingly connected with the second adjusting wheel (216); the second adjusting wheel (216) is meshingly connected with the third adjusting wheel (218); the second adjusting wheel (216) and the third adjusting wheel (218) are arranged to rotate in opposite directions.

7. The NMP distillation device according to claim 6, characterized in that: Two fixing bars (210) are fixedly connected inside the operation box (201), and the fixing bars (210) are symmetrically arranged on both sides of the first adjustment wheel (215). Two groups of first constraint wheels (212) are arranged on both sides of the first adjustment wheel (215), and each group of the first constraint wheels (212) is arranged on the upper and lower sides of the liquid-drawing rope body (203). The first constraint wheels (212) are fitted with the liquid-drawing rope body (203) through grooves provided on the surface, and first mounting bars (211) are arranged on both sides of each group of the first constraint wheels (212). The first mounting bars (211) are fixedly connected to the corresponding fixing bars (210), and the first constraint wheels (212) are rotatably connected to the corresponding two first mounting bars (211) through two fifth bearings.

8. The NMP distillation device according to claim 7, characterized in that: The liquid-drawing rope body (203) comprises an outer rope loop (2031) located on the outside, the surface of the outer rope loop (2031) is hollow, a plurality of driving balls (2032) are fixedly connected to the inside of the outer rope loop (2031) at equal intervals, a liquid-drawing inner core (2033) is arranged on the inside of the liquid-drawing rope body (203), the liquid-drawing inner core (2033) is located in a through hole provided on the surface of the driving ball (2032) and is slidably connected to the driving ball (2032), and a plurality of curved grooves (209) are provided in a ring array in the groove provided on the surface of the driving wheel (208), and the curved grooves (209) correspond to the driving wheel (208).

9. The NMP distillation device according to claim 8, characterized in that: The two ends of the liquid-drawing rope body (203) are fixedly connected in the following manner: one end of the outer rope loop (2031) is fixedly connected to a lower connecting portion (2034), and the other end of the outer rope loop (2031) is fixedly connected to an upper connecting portion (2035); a thread groove (2039) is provided on the bottom surface of the upper connecting portion (2035); the lower connecting portion (2034) is threadedly connected to the upper connecting portion (2035) via the thread groove (2039); and the two ends of the liquid-drawing inner core (2033) located inside the outer rope loop (2031) are fixedly connected to each other.

10. The NMP distillation device according to claim 9, characterized in that: The upper connecting portion (2035) has a plurality of accommodating grooves (2036) formed in a circular array inside, each of the accommodating grooves (2036) is fixedly connected to a fourth round rod (2038), and the surface of the fourth round rod (2038) is rotatably connected to an L-shaped block (2037).

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