Pre-polymerization kettle with dual liquid level monitoring function

Abstract

The invention relates to a prepolymerization kettle with a dual liquid level monitoring function. The prepolymerization kettle comprises a kettle body and a separation mechanism which is arranged on the kettle body and is used for separating byproducts, the separation mechanism comprises a stirring assembly arranged at the top of the kettle body, two groups of membrane preparation assemblies arranged in the kettle body, two groups of extrusion assemblies which are arranged in the kettle body and are positioned below the membrane preparation assemblies, vibration assemblies arranged on the extrusion assemblies, and feeding assemblies which are arranged on the extrusion assemblies and are positioned below the extrusion assemblies; the separation mechanism is matched with the circulation mechanism to realize the functions of quickly discharging by-product bubbles and uniformly distributing monomers, polymers and catalysts in the kettle body, and the technical problems that the viscosity of raw materials is increased, the by-products are difficult to quickly discharge, local overheating is caused and the catalysts are not uniformly distributed are solved.

Description

Technical Field

[0001] The invention relates to the technical field of double liquid level monitoring prepolymerization kettles, in particular to a prepolymerization kettle with double liquid level monitoring. Background Art

[0002] The prepolymerization kettle is mainly used for prepolymerization reaction, mixing low-viscosity monomers into high-viscosity prepolymers. During the process, heating and vacuuming are used to diffuse small molecular by-products in the raw materials (such as water and ethylene glycol) from the high-viscosity prepolymer into the gas phase for separation. The prepolymerization kettle with dual liquid level monitoring uses two independent measurement systems with different measurement principles (for example: one uses a radar level gauge and the other uses a differential pressure transmitter; or one uses a servo level gauge and the other uses an ultrasonic level gauge) to monitor the liquid level, thereby minimizing the occurrence of liquid level loss of control due to single-point failure of the instrument.

[0003] Chinese patent CN219849524U discloses a catalyst feeding device for a polylactic acid production prepolymerization kettle, which relates to the technical field of polylactic acid production. The device comprises a reactor body, a catalyst storage unit is fixedly installed on the right outer surface of the reactor body, a polylactic acid production mixing device is rotatably installed inside the reactor body, and a catalyst feeding device is arranged inside the catalyst storage unit.

[0004] In the prior art, the increased viscosity of the raw materials causes a sharp increase in diffusion resistance, which in turn leads to technical problems such as the slow rise of by-product bubbles generated during vacuum devolatilization in the high-viscosity prepolymer, which is easy to remain and form product defects, poor fluidity of the high-viscosity material, local overheating caused by the thickening of the boundary layer, and poor dispersion ability of the catalyst due to excessive concentration of catalyst addition in the high-viscosity material. Summary of the Invention

[0005] The purpose of the present invention is to address the shortcomings of the existing technology and provide a prepolymerization kettle with dual liquid level monitoring. The separation mechanism cooperates with the circulation mechanism to achieve the rapid discharge of by-product bubbles and the uniform distribution of monomers, polymers and catalysts in the kettle body, thereby solving the technical problems of difficult rapid discharge of by-products due to increased raw material viscosity, local overheating and uneven catalyst distribution.

[0006] To achieve the above object, the present invention provides the following technical solution: a prepolymerization kettle with dual liquid level monitoring, comprising a kettle body, and a separation mechanism disposed on the kettle body and used to separate by-products; The separation mechanism includes a stirring assembly arranged on the top of the kettle body, two sets of film-making assemblies arranged inside the kettle body, two sets of extrusion assemblies arranged inside the kettle body and located below the film-making assemblies, a vibration assembly arranged on the extrusion assembly, and a feeding assembly arranged on the extrusion assembly and located below the extrusion assembly; During the continuous input and output of raw materials in the prepolymerization kettle, the stirring component mixes and stirs by penetrating into the bottom of the liquid raw materials, gradually changing the monomer raw materials into the direction of polymers. At the same time, the film-forming component continuously extracts the raw materials and guides them to form a liquid layer on the inner wall of the kettle by gravity. Cooperating with the heating device, extrusion component and vibration component embedded in the inner wall of the kettle, the separation of small molecule by-products such as water and ethylene glycol is accelerated. At the same time, the feeding component intermittently adds the catalyst into the gap of the liquid layer after extrusion, and finally merges it with the raw materials below.

[0007] Furthermore, the stirring assembly includes a stirring shaft passing through the top of the kettle body, a stirring paddle connected to the bottom of the stirring shaft and located in the kettle body, and a driving motor connected to the kettle body and with its output end connected to the stirring shaft.

[0008] Furthermore, the film-making assembly includes a fan-shaped plate connected to the inner wall of the kettle body through a mounting column, an extraction cylinder connected to the fan-shaped plate and communicated therewith, a spiral dragon connected to the extraction cylinder, and a first motor connected to the mounting column and with the output end connected to the spiral dragon.

[0009] Furthermore, the extrusion assembly includes a supporting frame connected to the kettle body, extrusion rollers connected to the supporting frame at both ends through circular rings, a first follower gear connected to the circular ring, a second motor connected to the supporting frame, and a first driving gear connected to the output end of the second motor and meshing with the first follower gear for transmission.

[0010] Furthermore, the vibration assembly includes a mounting frame connected to the carrier frame and located inside the extrusion roller, multiple groups of knocking racks connected to the mounting frame through a first telescopic member, a transmission shaft connected to the mounting frame, multiple groups of half gears connected to the transmission shaft and meshing with the corresponding knocking racks for transmission, a second follower gear connected to the transmission shaft, and a second driving gear connected to the ring and meshing with the second follower gear for transmission.

[0011] Furthermore, the feeding assembly includes a guide frame connected to the supporting frame, a first reciprocating screw connected to the guide frame, a belt transmission member whose two ends are respectively connected to the first reciprocating screw and the second motor, a slider connected to the guide frame and connected to the first reciprocating screw, a telescopic plate connected to the slider through a second telescopic member, a conveying frame connected to the supporting frame, a conveying pipe connected to the conveying frame, a driving plate connected to the conveying frame and connected to the telescopic plate through a rotating shaft, a semi-toothed ring connected to the driving plate, multiple groups of discharge pipes connected to the conveying frame, a follower gear ring connected to the discharge pipe and meshing with the semi-toothed ring for transmission, and connecting grooves respectively opened on the discharge pipe and the conveying frame.

[0012] Furthermore, the invention also includes a circulation mechanism arranged on the kettle body; The circulation mechanism includes a scraping assembly arranged on the kettle body and used to drive the edge raw materials to move inward, a filling assembly arranged on the scraping assembly and used to prevent dry burning after the raw materials in the upper heating part are scraped off, and a cutting assembly arranged on the stirring assembly and used to prevent the polymer from obstructing the stirring assembly.

[0013] Furthermore, the wall scraping assembly includes a driving gear ring connected to the kettle body, a third motor connected to the kettle body, a driving gear connected to the output end of the third motor and meshing with the driving gear ring for transmission, a first conveying frame connected to the driving gear ring, a second conveying frame connected to the first conveying frame, a third conveying frame connected to the second conveying pipe, and two sets of avoidance members provided on the carrier frame; The avoidance member includes a avoidance gear arranged on the kettle body, a avoidance rack connected to the carrier and meshing with the avoidance gear, and a avoidance gear ring arranged on the first conveying frame and meshing with the avoidance gear.

[0014] Furthermore, the replacement component includes a valve stem connected to the second conveying frame, a valve plate connected to the valve stem, a regulating gear connected to the first conveying frame, gear teeth connected to the valve stem and meshing with the regulating gear, a regulating rack connected to the fan-shaped plate and meshing with the regulating gear, a trigger rod connected to the valve stem, and a brake rod connected to the fan-shaped plate and used to drive the trigger rod to rotate.

[0015] Furthermore, the cutting assembly includes a second reciprocating screw connected to the stirring shaft, a limiting rod connected to the kettle body, a movable ring connected to the limiting rod and connected to the second reciprocating screw, and a cutter connected to the movable ring through a long rod.

[0016] The beneficial effects of the present invention are: (1) The present invention sets up a prepolymerization kettle with dual liquid level monitoring. Through two independent measurement systems with different measurement principles, the volume of raw materials inside the kettle is controlled, and the feed solenoid valves of the two groups of raw materials are remotely controlled at the same time, thereby maintaining the balance between feeding and discharging. It also effectively prevents the occurrence of dry burning and overflowing caused by single-point failure of the instrument during long-term continuous operation of the kettle.

[0017] (2) The present invention provides a separation mechanism so that the raw materials can change their own form and fall down from top to bottom on the inner wall of the kettle body in the form of a liquid layer by relying on gravity. During the process, the raw materials are heated by a heating device embedded in the inner wall of the kettle body, thereby allowing small molecular by-products such as water and ethylene glycol to form bubbles that are quickly separated from the raw materials. This solves the problem that the diffusion resistance increases sharply due to the increase in the viscosity of the raw materials, which causes the by-product bubbles generated during vacuum devolatilization to rise slowly in the high-viscosity prepolymer and easily remain and form product defects.

[0018] (3) The present invention provides a scraping assembly and a filling assembly to promptly scrape off the raw materials that have stayed on the inner wall of the kettle for a long time and provide new raw materials at the scraping position, thereby achieving the effects of increasing heat exchange efficiency, promoting the mixing of new and old raw materials, and reducing the occurrence of scaling.

[0019] (4) The present invention cuts off the polymer around the stirring shaft by setting a cutting component to prevent the prepolymer from being continuously entangled on the stirring shaft like sugar threads, thereby increasing the resistance to stirring, which is beneficial to reducing energy consumption and extending the service life of the equipment.

[0020] In summary, the present invention has the advantages of fast by-product discharge, few stirring dead corners and uniform catalyst distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the kettle body of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 Schematic diagram of the separation mechanism of the present invention; Figure 4 A schematic diagram of the extraction components of the present invention; Figure 5 A schematic diagram of an extrusion assembly of the present invention; Figure 6 This is a schematic diagram of the vibration assembly of the present invention; Figure 7 This is a schematic diagram of the feeding assembly of the present invention; Figure 8 This is a schematic diagram of the working state of the feeding assembly of the present invention; Figure 9 Schematic diagram of the circulation mechanism of the present invention; Figure 10 This is a schematic diagram of the working state of the scraper assembly of the present invention; Figure 11 This is a schematic diagram of the replacement component of the present invention; Figure 12 Schematic diagram of the cutting assembly of the present invention. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0024] Example 1 like Figures 1 to 3 As shown, this embodiment provides a prepolymerization reactor with dual liquid level monitoring, comprising a reactor body 100 and a separation mechanism 1 disposed on the reactor body 100 and used for separating by-products; The separation mechanism 1 includes a stirring assembly 11 disposed on the top of the kettle body 100, two sets of film-forming assemblies 12 disposed inside the kettle body 100, two sets of extrusion assemblies 13 disposed inside the kettle body 100 and located below the film-forming assemblies 12, a vibration assembly 14 disposed on the extrusion assembly 13, and a feeding assembly 15 disposed on the extrusion assembly 13 and located below the extrusion assembly 13; During the continuous input and output of raw materials in the prepolymerization kettle, the stirring component 11 mixes and stirs the liquid raw materials by penetrating into the bottom, gradually changing the monomer raw materials into the polymer direction. At the same time, the film-making component 12 continuously extracts the raw materials and guides them to form a liquid layer on the inner wall of the kettle body 100 by gravity. In conjunction with the heating device embedded in the inner wall of the kettle body 100 and the extrusion component 13 and the vibration component 14, the separation of small molecular by-products such as water and ethylene glycol is accelerated. At the same time, the feeding component 15 intermittently adds the catalyst into the gap of the liquid layer after extrusion, and finally merges it with the raw materials below.

[0025] In this embodiment, a separation mechanism 1 is provided to enable the raw material to change its form and fall from top to bottom on the inner wall of the kettle body 100 in the form of a liquid layer by gravity, and is heated during the process by a heating device embedded in the inner wall of the kettle body 100, thereby allowing bubbles formed by small molecular by-products such as water and ethylene glycol to be quickly separated from the raw material, thereby solving the problem that the diffusion resistance increases sharply due to the increase in the viscosity of the raw material, and the by-product bubbles generated during vacuum devolatilization rise slowly in the high-viscosity prepolymer and are easily left to form product defects.

[0026] It should be noted that the heating device embedded in the inner wall of the kettle body 100 is distributed in two places. The first place is the position where the raw materials are in contact at a fixed height of the kettle body 100, and the other place is the position where the extraction component drives the raw materials to flow through the inner wall of the kettle body 100; a valve for vacuuming and filling with nitrogen is provided on the top of the kettle body 100.

[0027] Further, if Figures 1 to 3 As shown, the stirring assembly 11 includes a stirring shaft 111 passing through the top of the kettle body 100, a stirring paddle 112 connected to the bottom of the stirring shaft 111 and located in the kettle body 100, and a driving motor 113 connected to the kettle body 100 and with its output end connected to the stirring shaft 111.

[0028] In this embodiment, a stirring component 11 is provided to stir the raw material from the bottom, so that the raw material forms a vortex spiral as a whole, and the raw material flows from the bottom center to the surrounding area, rises along the inner wall of the kettle body 100, and then flows to the center position, thereby promoting mixing with the new raw material on the top.

[0029] Further, if Figures 2 to 4 As shown, the film-making assembly 12 includes a fan-shaped plate 122 connected to the inner wall of the kettle body 100 through a mounting column 121, an extraction cylinder 123 connected to the fan-shaped plate 122 and communicated therewith, a spiral dragon 124 connected to the extraction cylinder 123, and a first motor 125 connected to the mounting column 121 and having its output end connected to the spiral dragon 124.

[0030] In this embodiment, the film forming assembly 12 is provided to extract the raw material and form a liquid layer on the inner wall of the kettle body 100, thereby increasing the surface area of ​​the raw material and the heating area, greatly reducing the difficulty of bubble separation and improving the separation efficiency.

[0031] In detail, in the process of the driving motor 113 driving the stirring shaft 111 and the stirring paddle 112 to process the raw materials, the film-making component 12 drives the spiral dragon 124 to rotate through the first motor 125, and then squeezes the raw materials into the fan-shaped plate 122 through the extraction cylinder 123. Subsequently, the raw materials contact the inner wall of the kettle body 100 at the outlet position of the fan-shaped plate 122, and flow downward along the inner wall of the kettle body 100 by gravity. During the process, due to the action of the heating device, the by-product bubbles begin to overflow and separate rapidly.

[0032] It should be noted that the end position of the extraction cylinder 123 can be adjusted as needed and set at the upper layer, middle layer and lower layer of the raw material. This solution only shows one of them.

[0033] Further, if Figures 2 to 3 and Figures 5 and 6As shown, the extrusion assembly 13 includes a carrier 131 connected to the kettle body 100, an extrusion roller 133 connected to the carrier 131 at both ends through a ring 132, a first follower gear 134 connected to the ring 132, a second motor 135 connected to the carrier 131, and a first driving gear 136 connected to the output end of the second motor 135 and meshing with the first follower gear 134 for transmission.

[0034] In this embodiment, an extrusion component 13 is provided to squeeze the originally freely falling liquid layer into a serrated shape. First, during the extrusion process, the contraction effect drives some smaller by-product bubbles in the raw material to be discharged faster. Second, it provides a certain barrier layer in which the catalyst is wrapped. In combination with the feeding component 15, it effectively prevents the added catalyst from polymerizing again after entering the raw material below.

[0035] In detail, during the falling process of the liquid layer, the second motor 135 drives the first driving gear 136 to rotate through the output end, and then drives the first follower gear 134 to rotate through the meshing action. Then the first follower gear 134 drives the ring 132 on the carrier 131 to rotate, and finally the ring 132 drives the squeezing roller 133 to rotate to squeeze the liquid layer into a serrated shape.

[0036] It should be noted that the surface coating of the extrusion roller 133 is a modified PTFE / fluoropolymer composite coating, which has excellent non-stickiness and high temperature resistance, and effectively prevents the raw materials from sticking and gathering on the extrusion roller 133.

[0037] Further, if Figure 6 As shown, the vibration assembly 14 includes a mounting frame 141 connected to the supporting frame 131 and located inside the squeezing roller 133, multiple groups of knocking racks 143 connected to the mounting frame 141 through a first telescopic member 142, a transmission shaft 144 connected to the mounting frame 141, multiple groups of half gears 145 connected to the transmission shaft 144 and engaged with the corresponding knocking racks 143 for transmission, a second follower gear 146 connected to the transmission shaft 144, and a second driving gear 147 connected to the ring 132 and engaged with the second follower gear 146 for transmission.

[0038] In this embodiment, the vibration component 14 is arranged inside the squeezing roller 133, so that the squeezing roller 133 can expel bubbles by contraction and cooperate with the vibration component 14 to accelerate the discharge of bubbles again under the vibration effect.

[0039] In detail, during the rotation of the ring 132 and the squeezing roller 133, the ring 132 drives the second driving gear 147 to rotate, and the second driving gear 147 then drives the transmission shaft 144 to rotate through the meshing action with the second follower gear 146, and multiple half gears 145 connected to the transmission shaft 144 rotate accordingly. When the half gears 145 rotate, they drive the upper knocking rack 143 to move, and the first telescopic member 142 contracts accordingly. When the half gears 145 are disengaged from the knocking rack 143, the first telescopic member 142 is elastically reset, driving the knocking rack 143 to knock and vibrate the inner wall of the squeezing roller 133.

[0040] It should be noted that, due to the different positions of the multiple half gears 145 , the timing of striking the rack 143 during rotation is different, thereby maintaining the continuous vibration of the squeezing roller 133 .

[0041] Further, if Figures 2 to 3 and Figures 7 and 8 As shown, the feeding assembly 15 includes a guide frame 151 connected to the carrier 131, a first reciprocating screw rod 152 connected to the guide frame 151, a belt transmission member 153 whose two ends are respectively connected to the first reciprocating screw rod 152 and the second motor 135, a slider 154 connected to the guide frame 151 and connected to the first reciprocating screw rod 152, a telescopic plate 155 connected to the slider 154 through a second telescopic member 1512, and a feeding member connected to the carrier 131. A conveying rack 156, a conveying pipe 157 connected to the conveying rack 156, a driving plate 158 connected to the conveying rack 156 and connected to the telescopic plate 155 through a rotating shaft, a half-toothed ring 159 connected to the driving plate 158, multiple groups of discharge pipes 1510 connected to the conveying rack 156, a follower gear ring 1511 connected to the discharge pipe 1510 and meshing with the half-toothed ring 159 for transmission, and a connecting groove 150 respectively opened on the discharge pipe 1510 and the conveying rack 156.

[0042] In this embodiment, by setting the feeding component 15 to cooperate with the raw material shaped by the extrusion component 13, the added catalyst is wrapped by the raw material, and the subsequently added catalyst will not contact the previous part, thereby increasing the distribution state of the catalyst. In addition, through the transmission cooperation with the extrusion component 13, the addition of the catalyst is more uniform.

[0043] In detail, when the second motor 135 drives the extrusion assembly 13 to work, the second motor 135 also drives the first reciprocating screw 152 to rotate through the belt transmission member 153. When the first reciprocating screw 152 rotates, it drives the slider 154 on the guide frame 151 to move. The slider 154 drives the telescopic plate 155 to move through the second telescopic member 1512. Since the driving plate 158 only moves on the arc edge on the conveying frame 156, the rotating shaft connected to the driving plate 158 drives the telescopic plate 155 to extend during the process and maintain the connection state. In addition, the driving plate 158 During the movement of the driving plate 158, the half gear ring 159 arranged on it engages with the follower gear ring 1511, thereby driving multiple discharge pipes 1510 to rotate 360° in turn. When the discharge pipe 1510 rotates, the connecting groove 150 opened on it is aligned with the connecting groove 150 on the conveying rack 156, and the catalyst is then pushed from the inside of the conveying rack 156 to the discharge pipe 1510, and then after being extruded from the end of the discharge pipe 1510, it contacts the sunken position of the serrated raw material and moves together with the downward movement of the raw material. When the two sets of connecting grooves 150 are misaligned, the catalyst stops outputting.

[0044] It should be noted that the catalyst is pushed to the conveying rack 156 by the conveying pipe 157. The conveying pipe 157 has a certain toughness. When the conveying rack 156 avoids, the conveying pipe 157 can undergo a certain deformation to maintain connectivity.

[0045] Further, if Figure 2 and Figure 9 As shown, the said further comprises a circulation mechanism 2 arranged on the kettle body 100; The circulation mechanism 2 includes a scraping assembly 21 arranged on the kettle body 100 and used to drive the edge raw materials to move inward, a filling assembly 22 arranged on the scraping assembly 21 and used to prevent dry burning after the raw materials in the upper heating part are scraped off, and a cutting assembly 23 arranged on the stirring assembly 11 and used to prevent the polymer from obstructing the stirring assembly 11.

[0046] In this embodiment, the circulation mechanism 2 is provided so that the raw materials in the kettle body 100 can be evenly blended, thereby reducing the scaling of the raw materials in the mixing dead corners and improving the production quality.

[0047] In detail, the scraping component 21 guides the raw materials at the edge position to the center position during operation, the filling component 22 performs timely material replenishment work after scraping the liquid layer position, and finally the cutting component 23 moves up and down at the stirring shaft 111 position to cut off the prepolymer around the stirring shaft 111 in time.

[0048] Further, if Figure 2 and Figures 9 to 11As shown, the wall scraping assembly 21 includes a driving gear ring 211 connected to the kettle body 100, a third motor 212 connected to the kettle body 100, a driving gear 213 connected to the output end of the third motor 212 and meshing with the driving gear ring 211 for transmission, a first conveying frame 214 connected to the driving gear ring 211, a second conveying frame 215 connected to the first conveying frame 214, a third conveying frame 216 connected to the second conveying pipe 157, and two sets of avoidance members 217 provided on the carrier 131; The avoidance member 217 includes a avoidance gear 2171 provided on the kettle body 100 , a avoidance rack 2172 connected to the carrier 131 and meshing with the avoidance gear 2171 , and a avoidance gear ring 2173 provided on the first conveying frame 214 and meshing with the avoidance gear 2171 .

[0049] It is worth mentioning here that, first, the raw materials concentrated inside the kettle body 100 have their diffusion resistance increased dramatically as the viscosity increases, and the raw materials at the edge do not flow as well as the raw materials near the center, gradually affecting the molding efficiency of the prepolymer and the efficiency of heat transfer. Secondly, since the liquid layer position relies solely on gravity, some raw materials that are close to the inner wall of the kettle body 100 may fall slowly and easily for a long time.

[0050] In detail, after a certain period of time, the scraping assembly 21 starts to work, and the third motor 212 drives the driving gear ring 211 to rotate through the driving gear 213, and the driving gear ring 211 drives the first conveying frame 214, the second conveying frame 215 and the third conveying frame 216 to rotate along the inner wall of the kettle body 100. During the process, the third conveying frame 216 scrapes the raw materials that flow slowly at the edge and guides them to the center position. At the same time, it absorbs the accumulated heat in time by releasing new raw materials, thereby preventing the continuous escalation of local problems. When the second conveying frame 215 moves to the liquid layer position, first the avoidance gear ring 2173 on the first conveying frame 214 drives the avoidance gear 2171 to rotate, and the avoidance gear 2171 drives the avoidance rack 2172 and the supporting frame 131 to move, and then drives the extrusion assembly 13 and the feeding assembly 15 to avoid through the supporting frame 131, and then the second conveying frame 215 starts to scrape the liquid layer quickly.

[0051] It should be noted that there are two ports for raw materials to enter, namely the inlet for direct feeding at the top, and the inlet set on the side to cooperate with the scraper assembly 21. The solenoid valves at the two inlets are connected to the two sets of liquid level monitoring devices through electrical signals for precise control of the liquid level; the driving gear ring 211 has a sealing effect on the raw material conveying trough set in the upper kettle body 100, and the raw materials enter the first conveying frame 214 through the conveying trough, and the first conveying frame 214 is respectively connected to the second conveying frame 215 and the third conveying frame 216.

[0052] Further, if Figures 9 to 11As shown, the replacement component 22 includes a valve stem 221 connected to the second conveying frame 215, a valve plate 222 connected to the valve stem 221, a regulating gear 223 connected to the first conveying frame 214, a gear tooth 224 connected to the valve stem 221 and meshing with the regulating gear 223, a regulating rack 225 connected to the fan-shaped plate 122 and meshing with the regulating gear 223, a trigger rod 226 connected to the valve stem 221, and a brake rod 227 connected to the fan-shaped plate 122 and used to drive the trigger rod 226 to rotate.

[0053] In this embodiment, the scraping part is replenished with raw materials in time by setting a filling component 22, which effectively prevents the empty part from drying out and heating up quickly. When the raw materials in the extraction component flow to the lower position, the polymer is decomposed by high temperature.

[0054] In detail, before the liquid layer is scraped off, the regulating gear 223 connected to the first conveying frame 214 is meshed with the regulating rack 225 on the fan-shaped plate 122 for transmission, so that the regulating gear 223 drives the valve stem 221 to rotate and open the second conveying frame 215 through the gear teeth 224, and then new raw materials are added to the scraping position while the liquid layer is scraped off, and are fitted with the inner wall of the kettle body 100 under the smoothing effect of the valve plate 222. When leaving the liquid layer position, the trigger rod 226 connected to the valve stem 221 is squeezed with the brake rod 227 on the fan-shaped plate 122, so that the valve plate 222 is reset and stops replenishing, and the extrusion assembly 13 and the feeding assembly 15 are driven to reset through the avoidance member 217.

[0055] Example 2 like Figure 2 and Figure 12 As shown, the components identical or corresponding to those in the first embodiment are designated by the corresponding reference numerals in the first embodiment. For simplicity, only the differences from the first embodiment are described below. The second embodiment differs from the first embodiment in that: like Figure 2 and Figure 12 As shown, the cutting assembly 23 includes a second reciprocating screw rod 231 connected to the stirring shaft 111, a limiting rod 232 connected to the kettle body 100, a movable ring 233 connected to the limiting rod 232 and connected to the second reciprocating screw rod 231, and a cutter 235 connected to the movable ring 233 through a long rod 234.

[0056] In this embodiment, a cutting assembly 23 is provided to cut the polymer around the stirring shaft 111 to prevent the prepolymer from being continuously entangled on the stirring shaft 111 like sugar threads, thereby increasing the resistance to stirring.

[0057] In detail, when the stirring shaft 111 rotates, it drives the second reciprocating screw 231 to rotate, and then the movable ring 233 mounted on the second reciprocating screw 231 moves up and down under the positioning of the limit rod 232, and the long rod 234 connected to the movable ring 233 drives the cutter 235 to move up and down along the stirring shaft 111 to cut the prepolymer near the stirring shaft 111.

[0058] Working steps Step 1: Film formation: While the stirring assembly 11 drives the raw materials inside the kettle 100 to react, the film forming assembly 12 extracts the raw materials and forms a film on the working position of the heating device on both sides of the inner wall of the kettle 100. The extracted raw materials fall on the inner wall of the kettle 100 by their own gravity to form a liquid layer, thereby increasing their own area and accelerating the discharge of by-product bubbles; Step 2: Shaping: The liquid layer is shaped into a sawtooth shape by the extrusion component 13. The extrusion and contraction and vibration of the vibration component 14 are used to accelerate the discharge of bubbles. When the liquid layer merges with the raw material below, the catalyst is added to the depression of the sawtooth liquid layer by the feeding component 15. Step three, maintenance, regularly start the scraping component 21, scrape the edge of the raw material and the liquid layer position to prevent scaling, and promote the mixing of new and old raw materials, and cooperate with the filling component 22 to replenish new raw materials in time at the liquid layer scraping position to prevent the liquid layer position from absorbing heat and heating up too quickly due to lack of raw materials. In addition, the cutting component 23 is used to cut off the prepolymer near the stirring shaft 111 to reduce the working pressure of the stirring shaft 111.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A prepolymerization reactor with dual liquid level monitoring, characterized in that: It includes a kettle body and a separation mechanism arranged on the kettle body and used for separating by-products; The separation mechanism includes a stirring assembly arranged on the top of the kettle body, two sets of film-making assemblies arranged inside the kettle body, two sets of extrusion assemblies arranged inside the kettle body and located below the film-making assemblies, a vibration assembly arranged on the extrusion assembly, and a feeding assembly arranged on the extrusion assembly and located below the extrusion assembly; During the continuous input and output of raw materials in the prepolymerization kettle, the stirring component mixes and stirs by penetrating into the bottom of the liquid raw materials, gradually changing the monomer raw materials into the direction of polymers. At the same time, the film-forming component continuously extracts the raw materials and guides them to form a liquid layer on the inner wall of the kettle by gravity. Cooperating with the heating device, extrusion component and vibration component embedded in the inner wall of the kettle, the separation of small molecule by-products such as water and ethylene glycol is accelerated. At the same time, the feeding component intermittently adds the catalyst into the gap of the liquid layer after extrusion, and finally merges it with the raw materials below.

2. The prepolymerization reactor with dual liquid level monitoring according to claim 1, characterized in that: The stirring assembly includes a stirring shaft passing through the top of the kettle body, a stirring paddle connected to the bottom of the stirring shaft and located in the kettle body, and a driving motor connected to the kettle body and having an output end connected to the stirring shaft.

3. The prepolymerization reactor with dual liquid level monitoring according to claim 2, characterized in that: The film-making assembly includes a fan-shaped plate connected to the inner wall of the kettle body through a mounting column, an extraction cylinder connected to the fan-shaped plate and communicated therewith, a spiral dragon connected to the extraction cylinder, and a first motor connected to the mounting column with the output end connected to the spiral dragon.

4. The prepolymerization reactor with dual liquid level monitoring according to claim 3, characterized in that: The extrusion assembly includes a carrier connected to the kettle body, an extrusion roller with both ends connected to the carrier through a ring, a first follower gear connected to the ring, a second motor connected to the carrier, and a first driving gear connected to the output end of the second motor and meshing with the first follower gear for transmission.

5. The prepolymerization reactor with dual liquid level monitoring according to claim 4, characterized in that: The vibration assembly includes a mounting frame connected to the carrier frame and located inside the squeezing roller, multiple groups of knocking racks connected to the mounting frame through first telescopic members, a transmission shaft connected to the mounting frame, multiple groups of half gears connected to the transmission shaft and meshing with the corresponding knocking racks for transmission, a second follower gear connected to the transmission shaft, and a second driving gear connected to the ring and meshing with the second follower gear for transmission.

6. The prepolymerization reactor with dual liquid level monitoring according to claim 5, characterized in that: The feeding assembly includes a guide frame connected to the supporting frame, a first reciprocating screw connected to the guide frame, a belt transmission member with two ends respectively connected to the first reciprocating screw and the second motor, a slider connected to the guide frame and connected to the first reciprocating screw, a telescopic plate connected to the slider through a second telescopic member, a conveying frame connected to the supporting frame, a conveying pipe connected to the conveying frame, a driving plate connected to the conveying frame and connected to the telescopic plate through a rotating shaft, a semi-toothed ring connected to the driving plate, multiple groups of discharge pipes connected to the conveying frame, a follower gear ring connected to the discharge pipe and meshing with the semi-toothed ring for transmission, and connecting grooves respectively opened on the discharge pipe and the conveying frame.

7. The prepolymerization reactor with dual liquid level monitoring according to claim 4, characterized in that: The invention also includes a circulation mechanism arranged on the kettle body; The circulation mechanism includes a scraping assembly arranged on the kettle body and used to drive the edge raw materials to move inward, a filling assembly arranged on the scraping assembly and used to prevent dry burning after the raw materials in the upper heating part are scraped off, and a cutting assembly arranged on the stirring assembly and used to prevent the polymer from obstructing the stirring assembly.

8. The prepolymerization reactor with dual liquid level monitoring according to claim 7, characterized in that: The wall scraping assembly includes a driving gear ring connected to the kettle body, a third motor connected to the kettle body, a driving gear connected to the output end of the third motor and meshing with the driving gear ring for transmission, a first conveying frame connected to the driving gear ring, a second conveying frame connected to the first conveying frame, a third conveying frame connected to the second conveying pipe, and two sets of avoidance members provided on the carrier frame; The avoidance member includes a avoidance gear arranged on the kettle body, a avoidance rack connected to the carrier and meshing with the avoidance gear, and a avoidance gear ring arranged on the first conveying frame and meshing with the avoidance gear.

9. The prepolymerization reactor with dual liquid level monitoring according to claim 8, characterized in that: The replacement assembly includes a valve stem connected to the second conveying frame, a valve plate connected to the valve stem, a regulating gear connected to the first conveying frame, gear teeth connected to the valve stem and meshing with the regulating gear, a regulating rack connected to the fan-shaped plate and meshing with the regulating gear, a trigger rod connected to the valve stem, and a brake rod connected to the fan-shaped plate and used to drive the trigger rod to rotate.

10. The prepolymerization reactor with dual liquid level monitoring according to claim 9, characterized in that: The cutting assembly includes a second reciprocating screw connected to the stirring shaft, a limiting rod connected to the kettle body, a moving ring connected to the limiting rod and connected to the second reciprocating screw, and a cutter connected to the moving ring through a long rod.

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