Kettle body structure and polylactic acid production polymerization kettle based on kettle body structure
By designing the spiral guide tube and stirring components in the reactor structure, the problems of uneven stirring and "laminar dead zone" in polylactic acid production were solved, enabling rapid and uniform mixing of high-viscosity polylactic acid and improving production efficiency.
Patent Information
- Application Number
- CN202520579381.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2035-03-31
AI Technical Summary
In the existing technology, there are problems with insufficient stirring and uneven mixing in the production process of polylactic acid, especially at high molecular weight, where "laminar flow dead zones" are prone to occur, resulting in excessively long reaction times.
The reactor adopts a vessel structure design, including a spiral guide tube and a stirring assembly. Through the tilt angle and guide hole design of the spiral guide tube, combined with the circulating temperature control channel, the polylactic acid raw material can be mixed quickly and evenly. The upper and lower spiral plates of the stirring assembly work together to form a circulating flow state, avoiding the formation of "laminar dead zones".
It significantly improves the axial and radial mixing uniformity of high-viscosity polylactic acid prepolymer, shortens the reaction time, and increases production efficiency.
Smart Images
Figure CN223717148U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of polylactic acid production technology, and specifically relates to a reactor structure and a polylactic acid production polymerization reactor based on the reactor structure. Background Technology
[0002] Polylactic acid, also known as polylactide, is a polymer obtained by polymerization of lactic acid as the main raw material. It belongs to the polyester family. The raw material source of polylactic acid is abundant and renewable, the production process is pollution-free, and the product can be biodegradable, realizing the cycle in nature. It is an ideal green polymer material.
[0003] In the production of polylactic acid (PLA), existing technologies often utilize stirred reactors to ensure the reaction of raw materials within the stirred tank, thereby generating PLA. However, high molecular weight PLA exhibits reduced flowability and increased viscosity, making it prone to insufficient and uneven mixing with traditional impellers. This prevents lactide from being fully converted into PLA. Traditional single-layer impeller or anchor mixers also exhibit significant "laminar dead zones" when the PLA's reaction viscosity reaches a certain level, leading to uneven radial and axial mixing and consequently, excessively long reaction times. Utility Model Content
[0004] In view of the problems in the related technologies, this utility model proposes a reactor structure and a polylactic acid production polymerization reactor based on the reactor structure, so as to overcome the above-mentioned technical problems existing in the existing related technologies.
[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:
[0006] This utility model is a vessel structure, including a vessel body, a stirring assembly disposed in the middle of the inner cavity of the vessel body, a spiral guide tube disposed on the inner wall of the vessel body, the upper part of the spiral guide tube extending to the middle of the stirring assembly, the bottom of the spiral guide tube extending to the middle of the bottom side of the vessel body, and a circulating temperature control channel disposed on the outer wall of the vessel body, the circulating temperature control channel covering the lower part of the vessel body.
[0007] Furthermore, the bottom of the spiral guide tube is inclined at an angle of 15° to 30° with the cross-section of the vessel body, the upper half of the spiral guide tube is provided with a guide hole, the bottom of the spiral guide tube is provided with an inlet hole, the inlet hole has a sloping cross-section, and the inlet hole is inclined downward.
[0008] Furthermore, a drive motor is installed above the vessel body, and a torque sensor is installed at the output end of the drive motor. The bottom of the torque sensor is connected to the stirring assembly.
[0009] Further, the stirring assembly comprises an upper stirring spiral plate and a lower stirring spiral plate, the upper stirring spiral plate is opposite to the lower stirring spiral plate in spiral direction, the spiral flow guide cylinder is located between the upper stirring spiral plate and the lower stirring spiral plate, and the upper stirring spiral plate is connected with the torque sensor.
[0010] Further, the upper stirring spiral plate and the lower stirring spiral plate are coaxially arranged, and the lower stirring spiral plate is located above the bottom of the spiral flow guide cylinder.
[0011] Further, the circulating temperature control channel is externally provided with a heat preservation layer, and comprises a circulating coil and an external temperature control device, and two ends of the circulating coil are connected with the external temperature control device.
[0012] A polylactic acid production polymerization kettle comprises the kettle body mechanism, a feeding opening is arranged above the kettle body, and a discharging opening is arranged at the bottom of the kettle body.
[0013] The polylactic acid raw material is stirred and mixed in the kettle body by the stirring assembly after the polylactic acid raw material is added into the kettle body, the polylactic acid raw material is driven to rotate in the kettle body, the upper stirring spiral plate in the stirring assembly throws and disperses the polylactic acid raw material upwards and outward when rotating, the lower stirring spiral plate gathers the falling polylactic acid raw material to the lower part of the middle of the kettle body when rotating, and the spiral flow guide cylinder guides the polylactic acid raw material from the bottom of the kettle body to the upper part, so that the polylactic acid raw material forms a circulating flow state, and the polylactic acid raw material is mixed faster and more uniformly; meanwhile, the polylactic acid raw material is gathered to the bottom of the kettle body, when the rotating speed reaches a certain value, the polylactic acid raw material at the bottom of the kettle body diffuses to the inner wall of the kettle body due to the centrifugal force, the spiral flow guide cylinder forms directional flow by the inclination angle, and the polylactic acid raw material flows along the spiral flow guide cylinder, wherein the spiral flow guide cylinder is arranged at an inclination angle of ° to °, different inclination degrees of the spiral flow guide cylinder are adopted when polylactic acid with different viscosities is processed, when polylactic acid with low viscosity is processed, the spiral flow guide cylinder with an inclination angle of ° is adopted, so that the polylactic acid raw material can normally flow in the spiral flow guide cylinder, when polylactic acid with high viscosity is processed, the spiral flow guide cylinder with an inclination angle of ° is adopted, so that the polylactic acid raw material can better flow in the spiral flow guide cylinder, the polylactic acid raw material enters from the guide hole at the bottom of the spiral flow guide cylinder due to the centrifugal force generated by rotation, flows along the spiral flow guide cylinder, and then flows into the kettle body from the guide hole in the upper half of the spiral flow guide cylinder, the guide hole in the upper half of the spiral flow guide cylinder uniformly distributes, local turbulence is generated when the polylactic acid raw material flows out, the shear force of the material passing through the guide hole is increased, and the mixing of the polylactic acid raw material is promoted.
[0014] The circulating temperature control channel arranged in the kettle body is used to heat the inner wall of the kettle body, the external temperature control device connected to the two ends of the circulating coil of the circulating temperature control channel can be used to circulate hot oil, the hot oil enters the external temperature control device from one end of the circulating coil and flows back to the external temperature control device from the other end, so that the circulating temperature control is formed, and the kettle body is heated, and meanwhile, the external heat preservation layer is arranged to heat preservation, so that the temperature loss is avoided; the polylactic acid raw material flows in the spiral flow guide cylinder, is contacted with the heating treatment outside the kettle body, is uniformly heated, and when the polylactic acid raw material flows to the upper side of the spiral flow guide cylinder, flows into the kettle body again, so that the polylactic acid raw material circulates between the spiral flow guide cylinder and the stirring assembly, and the "laminar flow dead zone" in the traditional polymerization kettle is avoided, and the axial and radial mixing uniformity of the high-viscosity polylactic acid prepolymer is significantly improved.
[0015] Of course, it is not necessary for any product implementing the present application to achieve all the advantages mentioned above at the same time. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.
[0017] Figure 1 It is a whole three-dimensional structure schematic diagram of the present application;
[0018] Figure 2 It is a kettle body internal partial cross-sectional structure schematic diagram of the present application;
[0019] Figure 3 It is a kettle body internal cross-sectional exploded structure schematic diagram one of the present application;
[0020] Figure 4 It is a kettle body internal cross-sectional exploded structure schematic diagram two of the present application.
[0021] In the drawings, the component list represented by each number is as follows:
[0022] 1, kettle body; 11, driving motor; 12, torque sensor; 13, feeding port; 2, stirring assembly; 21, upper layer stirring spiral plate; 22, lower layer stirring spiral plate; 3, spiral flow guide cylinder; 31, flow guide hole; 32, lead-in hole; 4, circulating temperature control channel; 41, heat preservation layer; 42, circulating coil. DETAILED DESCRIPTION
[0023] With reference to the drawings of the utility model embodiments, the technical solutions in the utility model embodiments will be clearly and completely described below. Obviously, the described embodiments are only a part of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the utility model.
[0024] In the description of the utility model, it should be understood that the terms "opening", "upper", "lower", "top", "middle", "inner" and the like indicate the orientation or positional relationship, which are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the components or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the utility model.
[0025] Please refer to Figures 1-4 As shown in the figure, the utility model is a kettle body structure and a polylactic acid production polymerization kettle based on the kettle body structure, which comprises a kettle body 1, a stirring assembly 2 is arranged in the middle of the inner cavity of the kettle body 1, a spiral flow guide cylinder 3 is arranged on the inner wall of the kettle body 1, the spiral flow guide cylinder 3 extends to the middle part of the stirring assembly 2, the bottom of the spiral flow guide cylinder 3 extends to the middle part of the bottom side of the kettle body 1, a circulating temperature control channel 4 is arranged on the outer wall of the kettle body 1, and the circulating temperature control channel 4 is wrapped in the lower part of the kettle body 1.
[0026] When in use, after polylactic acid raw materials are added into the kettle body 1, the polylactic acid raw materials in the kettle body 1 are stirred and mixed by the stirring assembly 2, the polylactic acid raw materials are driven to rotate in the kettle body 1, and at the same time, the polylactic acid raw materials are gathered to the bottom of the kettle body 1, when the rotating speed reaches a certain value, the polylactic acid raw materials at the bottom of the kettle body 1 diffuse to the inner wall of the kettle body 1 due to the centrifugal force, at this time, the spiral flow guide cylinder 3 forms directional flow guide through the inclination angle thereof, and the polylactic acid raw materials are forced to flow along the spiral flow guide cylinder 3, then the circulating temperature control channel 4 arranged in the kettle body 1 is used to heat the inner wall of the kettle body, so that the polylactic acid raw materials flow in the spiral flow guide cylinder 3 and contact the heating treatment outside the kettle body 1, and the polylactic acid raw materials are uniformly heated, when the polylactic acid raw materials flow to the upper part of the spiral flow guide cylinder 3, they flow into the kettle body 1 again, so that the polylactic acid raw materials flow between the spiral flow guide cylinder 3 and the stirring assembly 2, and the "laminar flow dead zone" in the traditional polymerization kettle is avoided, and the axial and radial mixing uniformity of high-viscosity polylactic acid prepolymer is significantly improved.
[0027] In one embodiment, for the above-mentioned spiral draft tube 3, the bottom of the spiral draft tube 3 is inclined at an angle of 15°-30° with the transverse section of the kettle body 1, the upper half of the spiral draft tube 3 is provided with a flow guide hole 31, and the bottom of the spiral draft tube 3 is provided with a guide-in hole 32, the cross section of the guide-in hole 32 is a slope, and the guide-in hole 32 is inclined downward. By setting the spiral draft tube 3 at an angle of 15°-30°, different degrees of inclination of the spiral draft tube 3 are used for processing polylactic acid with different viscosities. When processing polylactic acid with low viscosity, a spiral draft tube 3 with an inclination angle of 30° is used, so that the polylactic acid raw material can flow normally inside the spiral draft tube 3. When processing polylactic acid with high viscosity, the flowability of the polylactic acid is reduced due to its high viscosity. At this time, a spiral draft tube 3 with an inclination angle of 15° is used, so that the polylactic acid raw material can flow better inside the spiral draft tube 3. The centrifugal force generated by the rotation of the polylactic acid raw material enters from the guide-in hole 32 at the bottom of the spiral draft tube 3, flows along the spiral draft tube 3, and then flows into the kettle body 1 from the flow guide hole 31 in the upper half of the spiral draft tube 3. The flow guide hole 31 uniformly distributed in the upper half of the spiral draft tube 3 generates local turbulence when the polylactic acid raw material flows out, increases the shear force when the material passes through the flow guide hole 31, and promotes the mixing of the polylactic acid raw material.
[0028] In one embodiment, for the above-mentioned kettle body 1, a drive motor 11 is arranged above the kettle body 1, a torque sensor 12 is arranged at the output end of the drive motor 11, and the bottom of the torque sensor 12 is connected with the stirring assembly 2. The drive motor 11 arranged above the kettle body 1 drives the stirring assembly 2 to rotate, and drives the polylactic acid raw material in the kettle body 1 to rotate, stir and mix. The torque sensor 12 arranged at the output end of the drive motor 11 detects the rotation torque, and then judges the polylactic acid polymerization condition.
[0029] In one embodiment, for the above-mentioned stirring assembly 2, the stirring assembly 2 includes an upper stirring spiral plate 21 and a lower stirring spiral plate 22, the spiral directions of the upper stirring spiral plate 21 and the lower stirring spiral plate 22 are opposite, the top of the spiral draft tube 3 is located between the upper stirring spiral plate 21 and the lower stirring spiral plate 22, and the upper stirring spiral plate 21 is connected with the torque sensor 12. When the upper stirring spiral plate 21 in the stirring assembly 2 rotates, it throws and disperses the polylactic acid raw material upward and outward, while the lower stirring spiral plate 22 rotates to gather the falling polylactic acid raw material downward in the middle of the kettle body 1. In combination with the spiral draft tube 3, the polylactic acid raw material is guided from the bottom of the kettle body 1 upward, so that the polylactic acid raw material forms a circulating flow state, and thus it is mixed faster and more uniformly.
[0030] In one embodiment, for the upper stirring spiral plate 21 described above, the upper stirring spiral plate 21 is coaxially arranged with the lower stirring spiral plate 22, and the lower stirring spiral plate 22 is located above the bottom of the spiral flow guide 3; by coaxially arranging the upper stirring spiral plate 21 and the lower stirring spiral plate 22, when the driving motor 11 is started, the upper stirring spiral plate 21 and the lower stirring spiral plate 22 rotate at the same time.
[0031] In one embodiment, for the circulating temperature control channel 4 described above, the circulating temperature control channel 4 is externally provided with a heat preservation layer 41, and the circulating temperature control channel 4 comprises a circulating coil 42 and an external temperature control device, and the two ends of the circulating coil 42 are connected with the external temperature control device; by the external temperature control device connected with the two ends of the circulating coil 42 of the circulating temperature control channel 4, the external temperature control device can adopt hot oil, which enters from one end of the circulating coil 42 and flows back to the external temperature control device from the other end, to form a circulating temperature control, thereby heating the kettle body 1, and at the same time, the external heat preservation layer 41 is used to heat preservation, so as to avoid temperature loss.
[0032] A polylactic acid production polymerization kettle comprises the kettle body mechanism, a feeding port 13 is arranged above the kettle body 1, and a discharge port is arranged at the bottom of the kettle body 1; the polylactic acid raw material is added through the feeding port 13 arranged above the kettle body 1; after the polylactic acid polymerization is completed, the lower stirring spiral plate 22 in the stirring assembly 2 is slowly rotated by the driving motor 11, and the speed of the lower stirring spiral plate 22 will not cause a large centrifugal force to make the polylactic acid material diffuse to the side of the kettle body 1; the polylactic acid material is gathered to the middle by the lower stirring spiral plate 22, and is discharged downward from the discharge port.
[0033] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the utility model. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0034] The preferred embodiments of the utility model disclosed above are only used to help explain the utility model. The preferred embodiments do not describe all the details, and the utility model is not limited to the specific embodiments described. Obviously, according to the content of the present specification, many modifications and changes can be made. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that the persons skilled in the art can well understand and utilize the utility model. The utility model is only limited by the claims and the entire scope and equivalents thereof.
Claims
1. A kettle body structure characterized by comprising: Including kettle body (1), the middle part of the inner chamber of kettle body (1) is provided with stirring assembly (2), the inner wall of kettle body (1) is provided with spiral draft tube (3), the upper part of spiral draft tube (3) extends to the middle part of stirring assembly (2), the bottom of spiral draft tube (3) extends to the middle part of the bottom side of kettle body (1), the outer wall of kettle body (1) is provided with circulating temperature control channel (4), and circulating temperature control channel (4) is wrapped in the lower part of kettle body (1).
2. A kettle body structure according to claim 1, wherein The bottom of the spiral draft tube (3) is inclined at an angle of 15°-30° with the transverse section of the kettle body (1), the upper half of the spiral draft tube (3) is provided with a flow guide hole (31), the bottom of the spiral draft tube (3) is provided with a guide hole (32), the cross section of the guide hole (32) is inclined, and the guide hole (32) is inclined downward.
3. The kettle body structure of claim 1, wherein The upper part of the kettle body (1) is provided with a driving motor (11), the output end of the driving motor (11) is provided with a torque sensor (12), and the bottom of the torque sensor (12) is connected with the stirring assembly (2).
4. A kettle body structure according to claim 3, wherein The stirring assembly (2) includes upper stirring spiral plate (21) and lower stirring spiral plate (22), the spiral direction of the upper stirring spiral plate (21) is opposite to that of the lower stirring spiral plate (22), the top of the spiral draft tube (3) is located between the upper stirring spiral plate (21) and the lower stirring spiral plate (22), and the upper stirring spiral plate (21) is connected with the torque sensor (12).
5. A kettle body structure according to claim 4, wherein The upper stirring spiral plate (21) and the lower stirring spiral plate (22) are coaxially arranged, and the lower stirring spiral plate (22) is located above the bottom of the spiral draft tube (3).
6. The kettle body structure of claim 1, wherein The outer part of the circulating temperature control channel (4) is provided with a heat preservation layer (41), the circulating temperature control channel (4) includes circulating coil (42) and external temperature control device, and the two ends of the circulating coil (42) are connected with the external temperature control device.
7. A polylactic acid production polymerization tank characterized by comprising: The kettle body mechanism comprises the kettle body (1), a feeding port (13) is arranged above the kettle body (1), and a discharging port is arranged at the bottom of the kettle body (1).