Horizontal prepolymerization reaction kettle

Abstract

The invention relates to the technical field of polymer synthesis equipment, in particular to a horizontal prepolymerization reaction kettle which comprises a horizontal kettle body, a mixing area and at least two tackifying areas are sequentially arranged in the horizontal kettle body in the material flowing direction, the adjacent areas are separated through baffles, and the heights of the baffles are decreased progressively in the material flowing direction to form a stepped overflow channel; the double-heating-medium synergistic heating system comprises a gas-phase heating medium loop arranged outside the horizontal kettle body and a liquid-phase heating medium loop arranged inside the horizontal kettle body; and the dynamic heating medium distribution unit is connected with the gas-phase heating medium loop and the liquid-phase heating medium loop, so that the dynamic heating medium distribution unit is used for dynamically adjusting the heat supply proportion of the two loops to the materials at different reaction stages. According to the invention, through collaborative innovation of a temperature control separation system of a double-loop heating medium and a step flow field design of a tackifying area, high-speed heating and high-viscosity fine temperature control of a whole reaction period are synchronously realized in a single set of system in a breakthrough manner.

Description

Technical Field

[0001] The invention relates to the technical field of polymer synthesis equipment, in particular to a horizontal prepolymerization reactor. Background Art

[0002] In the field of modified polyester prepolymerization, traditional vertical reactors have long faced two major technical bottlenecks. First, the heat medium temperature control system has inherent contradictions: conventional equipment uses a single heat medium heating mode. If a gaseous heat medium such as biphenyl-biphenyl ether is used, although rapid temperature rise can be achieved, when the material temperature exceeds 280°C, the coking rate on the reactor wall and agitator surface will increase sharply, seriously reducing product quality and shortening the equipment maintenance cycle. Conversely, if a liquid heat transfer oil such as hydrogenated terphenyl is used, although the risk of high-temperature coking can be reduced, its heating rate generally cannot meet the dual requirements of rapid temperature rise and precise temperature control in the polyester prepolymerization stage, resulting in a longer reaction cycle and a wider molecular weight distribution.

[0003] Secondly, the vertical reactor's fluid dynamics design suffers from significant flaws: Due to the static pressure gradient created by the axial liquid level difference, the material's residence time at different heights within the reactor varies significantly. Furthermore, the dead zone at the bottom accounts for 8%-15% of the volume, resulting in a standard deviation in outlet viscosity fluctuation exceeding 0.01 dL / g, directly impacting the stability of the subsequent final polymerization process. More seriously, this uneven flow field exacerbates localized overheating, creating a vicious cycle with the temperature control flaws of the single heat medium. The continuous accumulation of coke in high-temperature areas further disrupts the flow field, causing the viscosity qualification rate to remain at a low level for a long time.

[0004] Existing technologies have attempted to overcome these limitations. For example, some have proposed multi-stage vertical stirred tanks. While this approach improves mixing by increasing the number of agitators, it fails to address the uneven axial flow field, resulting in significant deviations in measured residence times. Other existing technologies employ composite heat transfer oils for enhanced temperature control, but due to the limited heat transfer efficiency of the liquid phase heat medium, the temperature rise from 230°C to 280°C still requires more than two hours. More importantly, the recent emergence of online viscosity control technology, while theoretically capable of closed-loop regulation, still suffers from significant control deviations due to the severe flow field disturbances in traditional reactors and the large fluctuations in viscometer measurements. This makes it impossible to meet the ±3% viscosity control requirements for high-end modified polyesters.

[0005] These existing technical difficulties fundamentally stem from a disconnect between equipment structural design and process control. Flow field defects amplify inadequate temperature control, while temperature control failures accelerate equipment fouling, ultimately creating a closed-loop bottleneck that hinders industry technological advancement. According to industry reports, these technical deficiencies have led to severely insufficient average capacity utilization in modified polyester production units, necessitating the urgent need to develop a next-generation prepolymerization reaction system to overcome the industry's technological ceiling. Summary of the Invention

[0006] The present invention aims to overcome the problem that traditional vertical reactors in the prior art cannot meet the dual requirements of rapid heating and precise temperature control in the polyester prepolymerization stage, and there is also the defect of uneven flow field inside the reactor. A horizontal prepolymerization reactor is provided to overcome the above shortcomings.

[0007] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions: In a first aspect, the present invention first provides a horizontal prepolymerization reactor, comprising: A horizontal kettle body, wherein a mixing zone and at least two viscosity-increasing zones are sequentially arranged inside the kettle along the material flow direction. Adjacent zones are separated by baffles, and the height of the baffles decreases along the material flow direction to form a stepped overflow channel. A dual-heat medium cooperative heating system, which includes a gas phase heat medium circuit arranged outside the horizontal kettle body, and a liquid phase heat medium circuit arranged inside the horizontal kettle body; The dynamic heat medium distribution unit is connected to the gas phase heat medium circuit and the liquid phase heat medium circuit, so as to dynamically adjust the heat supply ratio of the two circuits to the material at different reaction stages.

[0008] The inherent flaws of traditional vertical reactors have become a systemic bottleneck in the long-standing technical dilemma of modified polyester prepolymerization. This problem stems from the deeply coupled contradictions between equipment structure, heat transfer mechanism, and process control. The vertical configuration, due to the axial static pressure gradient, creates an uneven flow field, forcing material residence time dispersion as high as ±20%. This not only directly leads to outlet viscosity fluctuations but also compounds the temperature control shortcomings of a single heat medium. Using a high-temperature vapor-phase heat medium (such as biphenyl-diphenyl ether) for rapid temperature increase can lead to violent coking reactions above 280°C, clogging the flow path and degrading the product. While using a liquid-phase heat medium (such as hydrogenated terphenyl) can mitigate coking, its low heat transfer efficiency makes it impossible to meet the dual requirements of temperature increase and temperature maintenance during the prepolymerization stage. Furthermore, localized overheating caused by the dead zone at the bottom of the vertical reactor further amplifies the risk of coking, creating a vicious cycle of "flow field disturbance → temperature control failure → increased coking → flow field deterioration." The industry has tried to break the deadlock through local improvements such as multi-stage stirring or composite heat media, but has never been able to break through the fundamental constraints of equipment configuration and thermal management mode, resulting in capacity utilization rates below 85% for a long time and high scrap losses.

[0009] The creative breakthrough of the present invention begins with the re-deconstruction of the above-mentioned chain of contradictions. The inventors of this application first realized that the thermodynamic requirements of the prepolymerization reaction have significant time-varying characteristics, that is, the activation energy barrier (230→260°C) needs to be quickly broken through in the early stage of the reaction, while the condensation equilibrium (275±2°C) needs to be accurately maintained in the middle and late stages. The traditional single heat medium cannot take into account both requirements due to physical property limitations, and the simple superposition of two heat media will cause uneven heat distribution in the vertical structure due to flow field defects. Based on this, the inventors proposed the core concept of "horizontal multi-zone flow field reconstruction + dynamic adaptation of two heat media". By designing the reactor axially as a horizontal stepped overflow structure and using a baffle with decreasing height to force the formation of piston flow, the axial mixing dead zone of the vertical configuration is eliminated from the source, and the residence time deviation is compressed to ±3%.

[0010] This revolutionary structural change creates the physical foundation for dual-heat medium synergy: the gaseous heat medium, leveraging its high latent heat, rapidly heats up through the jacket, while the liquid-phase heat medium, relying on its high specific heat capacity, achieves precise temperature control via embedded coils / baffles. More importantly, the dynamic heat medium distribution unit adjusts the energy supply ratio between the two circuits in real time based on the reaction progress (gas-phase dominance >50% initially, liquid-phase dominance >60% later), aligning the heat transfer pattern with the reaction kinetics in both time and space. This three-dimensional synergy of "structure-function-control" essentially reshapes the design paradigm for prepolymer reactors.

[0011] The technical benefits of this solution are reflected in the simultaneous resolution of multiple contradictions. At the flow field level, the horizontal stepped overflow structure not only eliminates the axial backmixing common in traditional vertical reactors, but its decreasing baffle height also creates a self-cleaning flow channel, reducing the material residue rate from over 5% to negligible levels. At the thermal management level, the metabolic switching of the dual heat media not only meets the initial rapid temperature increase requirement (reducing the time by 40% compared to traditional methods), but also avoids the risk of high-temperature coking through the stable heat conduction of the liquid phase heat media, significantly reducing energy consumption per unit product. At the control level, the homogenization of the flow field ensures that online viscosity measurements accurately reflect the reaction progress. Combined with dynamic heat media distribution to form a closed-loop control system, viscosity fluctuations are reduced by over 60% compared to traditional equipment. Crucially, these technical effects are closely linked. The horizontal structure provides a carrier for the uniform distribution of the dual heat media, while the efficient heat transfer of the dual heat media lays the data foundation for intelligent control. These three mutually reinforce each other, forming a technological flywheel. Industry application data confirms that this reactor systematically solves the four-way paradox of "heating-coking-mixing-control" in the prepolymerization process, allowing the overall efficiency of modified polyester production to leap to a new generation level.

[0012] Compared to existing technologies, the present invention's unobviousness is particularly evident in three dimensions. First, conventional improvements are limited to single-dimensional optimization (simply increasing stirring intensity or modifying the heat medium formulation), but they fail to recognize the coupled relationship between equipment configuration and heat transfer mode. This present invention, on the other hand, is the first to integrate a horizontal piston flow design with dynamic dual-heat medium coupling as an integrated solution. This combination produces a super-additive effect. The stepped baffle structure unexpectedly provides support for the internal liquid-phase heat medium pipeline, while the horizontal low-liquid-level operation reduces the pressure requirement of the gas-phase heat medium jacket. Second, the design of the dynamic heat medium distribution unit breaks away from conventional temperature control thinking. While existing technologies generally use fixed ratios or PID control, this present invention switches the dominant heat medium type during the reaction phase. Its "metabolic" control logic is deeply aligned with the reaction kinetics of polyester polycondensation, making it an industry first. Third, this solution overturns the industry's perception that high temperatures inevitably lead to coking. By utilizing the spatiotemporal decoupling of the dual heat mediums, the coking rate is suppressed to extremely low levels even at 275°C, opening up a new process window for high-end polyester production.

[0013] Therefore, the reactor in this application is by no means a simple superposition of known features, but rather a new technical standard for pre-polymerization technology is constructed through cross-domain collaboration of structural innovation, material adaptation and control algorithms.

[0014] Preferably, the gas phase heat medium circuit includes a heating jacket arranged outside the horizontal kettle body, a gas phase heat medium pipeline connected to the heating jacket for conveying gas phase heat medium, and a heat medium evaporator for driving the gas phase heat medium to evaporate and circulate; The liquid phase heat medium circuit includes a spiral coil arranged inside the mixing zone and a serpentine heating pipe arranged inside the viscosity increasing zone, and also includes a liquid phase heat medium pipeline for transporting liquid phase heat medium to the spiral coil and the serpentine heating pipe.

[0015] This technical feature in the present application creates triple synergistic benefits by precisely matching the heat transfer requirements of the reaction process: first, the gas-phase heat medium circuit, with the help of the full-coverage layout of the jacket and the heat medium evaporation circulation mechanism, significantly enhances the overall rapid heating capability of the reactor, allowing the material to quickly break through the pre-polymerization activation energy barrier; second, the liquid-phase heat medium circuit has targetedly designed differentiated internals, the spiral coils in the mixing zone improve the melt mass transfer efficiency, and the serpentine heating tubes in the viscosity-increasing zone reduce the fluid shear disturbance, which effectively ensures the steady-state temperature control accuracy of highly viscous materials; finally, what is particularly critical is that the independent heat medium supply paths of the two circuits avoid the mutual exclusion of the physical properties of the heat transfer medium, so that the sudden heating advantage of the gas-phase heat medium and the constant temperature advantage of the liquid-phase heat medium are complementary in the spatial dimension, fundamentally solving the industry's chronic problem that the single-channel system is difficult to take into account both "rapid heating" and "high-temperature anti-coking".

[0016] Preferably, the gas phase heat medium in the gas phase heat medium circuit is a biphenyl-biphenyl ether mixture, and the operating temperature range is 270-290°C; The liquid phase heat medium in the liquid phase heat medium circuit is hydrogenated terphenyl, and the operating temperature range is 260-280°C.

[0017] Preferably, the number of the viscosity increasing zones is 3, and the height of the baffles decreases by 5%-15% of the liquid level along the material flow direction.

[0018] This application creates multiple process gains through a three-stage descending baffle structure: a 5%-15% liquid level gradient difference constructs a gradually shrinking flow channel, which not only provides a stable driving force to promote uniform advancement of the melt, but also suppresses material backmixing through a stepped pressure drop, so that the polymerization degree is increased step by step; the three-zone spatial division accurately matches the stage-by-stage needs of molecular chain growth, with the front zone achieving full mixing of oligomers, the middle zone driving the acceleration of the condensation reaction, and the final zone completing the orderly arrangement of the molecular chains; more importantly, the liquid level decrease and the horizontal configuration form a synergistic flow field effect, which enables high-viscosity melts to achieve self-cleaning flow without strong shear conditions, eliminating the axial concentration dead zone and local overheating problems inherent in traditional fully mixed flow reactors from the root, while creating an optimal heat transfer environment for the built-in heating elements.

[0019] Preferably, a disc turbine agitator is provided in the viscosity increasing zone, and the diameter of the agitator blade increases along the material flow direction.

[0020] The disc turbine agitator in this application has small-diameter blades in the front section that can reduce the turbulent shear of low-viscosity materials and avoid the breakage of oligomer molecular chains, while the blades that are gradually enlarged in the middle and rear sections construct an enhanced laminar flow field, which accurately adapts to the rheological characteristics requirements of the increased melt viscosity. In addition, the large-sized disc turbine at the end generates a controllable radial flow in the near-wall area, which not only enhances the axial conveying efficiency of the high-viscosity melt, but also avoids the local vortex caused by traditional axial flow blades. This force field configuration that progresses along the flow direction forms an orthogonal synergy with the horizontal stepped baffle structure, establishing a stable and continuous extended flow field in the molecular chain growth range, fundamentally eliminating the risk of uncontrolled branching caused by the viscosity gradient jump of the traditional reactor.

[0021] Preferably, the diameter of the stirring blade increases gradually by 0.1-0.2 μm, thereby forming a 120-180s interval between adjacent viscosity-increasing zones. -1 shear rate gradient.

[0022] Through the precisely customized blade amplification gradient, while the mild shear force field in the front zone protects the integrity of the newly formed oligomer molecular chains, the gradually enhanced rotational force field in the rear zone drives the high-viscosity melt to form an orderly orientation of the molecular chains. This not only eliminates the dual defects of traditional equal-diameter agitators, namely energy waste in the front zone and insufficient mixing in the rear zone, but also constructs a controlled extension environment for the molecular chains that continuously changes along the reaction path, so that the kinetic process of the polycondensation reaction and the evolution of the physical field of the equipment are spatially synchronized, completely avoiding the divergence of the molecular weight distribution caused by sudden local shear changes, and laying a core guarantee for obtaining modified polyesters with uniform branched structures.

[0023] Preferably, an EG cleaning system is also included, which includes an atomizing nozzle arranged at the top of the mixing zone, with an atomizing particle size of ≤100 μm and a spray angle of ≥90°.

[0024] Preferably, the EG cleaning system is further connected to a pressure pump.

[0025] Preferably, the apparatus further comprises a vacuum system for evacuating the horizontal kettle body, and a nitrogen protection device interlocked with the vacuum system.

[0026] Preferably, it also includes an intelligent controller connected to the dynamic heat medium distribution unit, which is based on the Elman neural network model, and outputs flow regulation instructions for the gas phase heat medium circuit and the liquid phase heat medium circuit by inputting parameters including material temperature, viscosity and vacuum degree.

[0027] The intelligent controller in this application is based on the dynamic memory characteristics of the Elman neural network, and integrates the nonlinear coupling of viscosity, temperature and vacuum in real time, thereby converting the empirical parameter association into a precise simulation prediction of the reaction path, so that the heat medium allocation decision goes beyond the conventional hysteresis feedback, and adapts in advance to the evolution of the molecular chain entanglement state of the polyester condensation phase, thereby converting the complex phase change of the reaction system into a continuous mapping relationship of the heat medium flow rate, constructing a forward-looking adjustment mechanism at the high-temperature anti-coking critical point, and forming the ability to actively shape the evolution of the polymer microstructure, thereby avoiding the process parameter oscillation caused by traditional on-off control at the essential level, and establishing the stability cornerstone of the continuous production process of high-quality modified polyester.

[0028] Therefore, the present invention has the following beneficial effects: The present invention essentially resolves the inherent contradiction between reaction efficiency and product quality in the traditional polyester production process through four collaborative innovations: a dual-circuit heat medium temperature control separation system, a step flow field design in the viscosity-increasing zone, a shear force field gradient matching structure, and an intelligent decision-making mechanism based on a neural network: a breakthrough is achieved by simultaneously achieving high-speed heating and high-viscosity fine temperature control throughout the entire reaction cycle in a single system, significantly improving polymerization uniformity and orientation distribution through dynamic adaptation of the physical flow field and molecular chain growth, and replacing passive response with intelligent predictive control, thereby fundamentally solving the branching structure defects and local sticking problems caused by hysteresis and oscillation of process parameters, and providing subversive technical support for the continuous preparation of highly transparent and uniform modified polyester. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the horizontal prepolymerization reactor in the present invention.

[0030] Figure 2 Schematic diagram of the structure of the baffle in the present invention.

[0031] Figure 3 Schematic diagram of the disc turbine agitator.

[0032] Figure 4 This is the atomization effect diagram of the EG nozzle in the reactor.

[0033] Among them, there are a horizontal kettle body 10, a reaction chamber 11, a mixing zone 12, a viscosity increasing zone 13, a baffle 14, an overflow port 15, a discharge port 16, a material inlet 17, a prepolymer discharge port 18, a viscometer 19, a dual heat medium collaborative heating system 20, a gas phase heat medium circuit 21, a liquid phase heat medium circuit 22, a heating jacket 23, a gas phase heat medium pipeline 24, a heat medium evaporator 25, a spiral coil 26, a serpentine heating tube 27, a liquid phase heat medium pipeline 28, a disc turbine agitator 30, a stirring blade 31, a dynamic heat medium distribution unit 40, a valve 41, an EG cleaning system 50, an atomizing nozzle 51, a nitrogen protection system 60, a vacuum system 61, a vacuum pump 62, a vacuum pipe 63, and a nitrogen protection device 64. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0035] Example 1 like Figure 1 As shown, this embodiment provides a horizontal prepolymerization reactor, which includes a horizontal reactor body 10, a reaction chamber 11 for prepolymerization of polyester is provided inside the reactor body 10, a material inlet 17 is provided on one side of the horizontal reactor body 10, and a prepolymer discharge port 18 is provided on the other side of the horizontal reactor body 10. The reaction material enters the reaction chamber 11 along the material inlet 17 to undergo prepolymerization reaction to obtain a prepolymer, which can then flow out from the prepolymer discharge port 18, and a viscometer 19 for detecting the viscosity of the prepolymer is also provided at the prepolymer discharge port 18.

[0036] The reaction chamber 11 is provided with a mixing zone 12 for mixing the reaction materials and at least two viscosity-enhancing zones 13 for increasing the molecular weight of the polyester, sequentially arranged along the material flow direction. To prevent axial back-mixing of the reaction materials during flow, in this embodiment, the mixing zone 12 and the viscosity-enhancing zones 13 within the reaction chamber 11 are separated from each other, as are adjacent viscosity-enhancing zones 13, by a baffle 14. To completely prevent axial back-mixing, the height of the baffles 14 along the material flow direction decreases along the material flow direction, thereby forming a stepped overflow channel from the mixing zone 12 to the last viscosity-enhancing zone 13.

[0037] In a specific embodiment of the present application, the number of viscosity increasing zones 13 is three, and the height of the baffle 14 of the mixing zone 12 and the first viscosity increasing zone 13 is 60% of the height of the horizontal kettle body 10, and the height of the subsequent baffles 14 decreases by 5%-15% of the liquid level height along the material flow direction.

[0038] like Figure 2 As shown, in a preferred embodiment of the present application, to ensure more uniform mixing of the materials and eliminate dead zones within the mixing zone 12 or the viscosity-enhancing zone 13, at least one discharge port 16 is provided at the bottom of the baffle 14. The material flux through the discharge port 16 is no more than 30% of the total material flow rate in the mixing zone 12 or the viscosity-enhancing zone 13. In addition, to ensure a more stable flow of the materials flowing out of the baffle 14, an overflow port 15 may also be provided at the top of the baffle 14.

[0039] like Figure 1 as well as Figure 3 As shown, in order to fully stir the material in the viscosity-increasing zone 13, in this embodiment, a disc turbine stirrer 30 is further provided inside the horizontal kettle body 10 for stirring the material in the viscosity-increasing zone 4. A plurality of stirring blades 31 corresponding to each viscosity-increasing zone 4 are provided on the stirrer, and the diameter of the stirring blades 31 increases along the material flow direction. Specifically, the diameter of the stirring blades 31 increases in a gradient of 0.1-0.2 μm, thereby forming a 120-180s between adjacent viscosity-increasing zones 4. -1 In addition, the surface roughness of the stirring blade 31 is Ra≤3.2μm, and its material is selected from Hastelloy C-276, so that the corrosion and wear resistance of the stirring blade 31 is improved to 5 times that of traditional stainless steel.

[0040] Further Figure 1As shown, in order to achieve heating of the material inside the reaction chamber 11 and thus provide a pre-polymerization environment for the material, in this embodiment, a gas-phase heat medium circuit 21 outside the horizontal kettle body 10 and a liquid-phase heat medium circuit 22 inside the horizontal kettle body 10 are further provided, so that the gas-phase heat medium circuit 20 and the liquid-phase heat medium circuit 22 cooperate with each other to form a dual-heat medium collaborative heating system 20.

[0041] Specifically, the gas phase heat medium circuit 21 includes a heating jacket 23 arranged outside the horizontal kettle body, and the heating jacket 23 is provided with a plurality of gas phase heat medium pipes 24 for passing in and out of the gas phase heat medium ( Figure 1 The arrows on the gaseous heat medium pipeline 24 indicate the flow direction of the gaseous heat medium into and out of the horizontal prepolymerization reactor. These gaseous heat medium pipelines 24 are connected in series with a heat medium evaporator 25 to continuously heat the materials within the reaction chamber 11. In this embodiment, the gaseous heat medium is a biphenyl-biphenyl ether mixture with an operating temperature range of 270-290°C, which can quickly increase the temperature of the materials within the reaction chamber 11 in the initial stage.

[0042] The liquid phase heat medium circuit 22 includes a spiral coil 26 disposed inside the mixing zone 12 and a serpentine heating pipe 27 disposed inside the viscosity increasing zone 13, thereby achieving a zoned heating function for the materials inside the mixing zone 12 and the viscosity increasing zone 13. The spiral coil 26 and the serpentine heating pipe 27 can be disposed independently of each other or connected to each other, and both are connected to a liquid phase heat medium pipeline 28 for conveying liquid phase heat medium ( Figure 1 The arrow on the liquid-phase heat medium pipeline 28 indicates the flow direction of the liquid-phase heat medium when entering and exiting the horizontal prepolymerization reactor. In this embodiment, the liquid-phase heat medium is selected from hydrogenated terphenyl, which has an operating temperature range of 260-280°C. It can provide stable heat to the materials inside the reaction chamber 11 in the middle and late stages of the reaction, thereby avoiding the risk of high-temperature coking of the materials by the gas-phase heat medium.

[0043] In order to achieve the heating distribution ratio of the gas-phase heat medium circuit 21 and the liquid-phase heat medium circuit 22 for the materials inside the reaction chamber 11, this embodiment is further provided with a set of dynamic heat medium distribution units 40 connected to the gas-phase heat medium circuit 21 and the liquid-phase heat medium circuit 22. The dynamic heat medium distribution units 40 are composed of a plurality of valves 41 connected to the gas-phase heat medium pipeline 24 and the liquid-phase heat medium pipeline 28. These valves 41 are controlled by an intelligent controller 42 based on the Elman neural network model. Parameters including heat medium temperature, stirring speed, and vacuum level are input to the intelligent controller 42, which then outputs flow control instructions for the gas-phase heat medium circuit and the liquid-phase heat medium circuit, automatically controlling the heating ratio of the gas-phase heat medium circuit 21 and the liquid-phase heat medium circuit 22.

[0044] In addition, in order to better clean the internal environment of the reaction chamber 11 , in this embodiment, an EG cleaning system 50 and a nitrogen protection system 60 are further provided in the horizontal kettle body 10 .

[0045] The EG cleaning system 50 includes an atomizing nozzle 51 located at the top of the mixing zone 3, and the atomizing particle size is ≤100μm. Figure 4 As shown, the spray angle is ≥90°, so that when the machine is stopped, it can be flushed in sections in the order of "mixing zone 12→thickening zone 13", that is: mixing zone 12→first thickening zone 13→second thickening zone 13→third thickening zone 13, with a flushing pressure of 0.3-0.5MPa and a time of 20-30min, so that the residual rate of the material can be reduced to below 0.3%.

[0046] The nitrogen protection system 60 includes a vacuum system 61 for evacuating the horizontal kettle body. The vacuum system 61 includes a vacuum pipe 63 connected to an external vacuum pump 62, and also includes a nitrogen protection device 64 linked to the vacuum system 61 through a pneumatic ball valve with a response time of less than 1s. When the vacuum environment inside the reaction chamber 11 needs to be broken, the vacuum pump 62 is first turned off, and then the vacuum pump 62 is opened at 5m. 3 / h nitrogen is introduced to maintain a slight positive pressure (5-10mbar) in the kettle, thus preventing air from contacting high-temperature materials.

[0047] The above-mentioned horizontal prepolymerization reactor was applied to the polyester prepolymerization process. The process operating parameters and dynamic temperature control data are shown in Table 1 and Table 2 respectively: Table 1

[0048] Table 2

[0049] The horizontal prepolymerization reactor in this application is compared with a conventional prepolymerization reactor. The comparison results are shown in Table 3 below: Table 3

[0050] As can be seen from the data in the table above, this invention, through the collaborative innovation of a dual-circuit heat medium temperature-controlled separation system, a stepped flow field design in the viscosity-increasing zone, and a shear force field gradient matching structure, fundamentally resolves the inherent contradiction between reaction efficiency and product quality in traditional polyester production. This breakthrough achieves both high-speed temperature rise and precise temperature control in the high-viscosity state throughout the entire reaction cycle within a single system. By dynamically adapting the physical flow field to molecular chain growth, polymerization uniformity and orientation distribution are significantly improved. Intelligent predictive control replaces passive response, fundamentally eliminating branching defects and localized sticking caused by hysteresis and oscillation of process parameters. This provides revolutionary technical support for the continuous production of highly transparent, uniform modified polyester.

[0051] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A horizontal prepolymerization reactor, characterized in that: include A horizontal kettle body, wherein a mixing zone and at least two viscosity-increasing zones are sequentially arranged inside the kettle along the material flow direction. Adjacent zones are separated by baffles, and the height of the baffles decreases along the material flow direction to form a stepped overflow channel. A dual-heat medium cooperative heating system, which includes a gas phase heat medium circuit arranged outside the horizontal kettle body, and a liquid phase heat medium circuit arranged inside the horizontal kettle body; The dynamic heat medium distribution unit is connected to the gas phase heat medium circuit and the liquid phase heat medium circuit, so as to dynamically adjust the heat supply ratio of the two circuits to the material at different reaction stages.

2. The horizontal prepolymerization reactor according to claim 1, wherein The gas phase heat medium circuit includes a heating jacket arranged outside the horizontal kettle body, a gas phase heat medium pipeline connected to the heating jacket for conveying gas phase heat medium, and a heat medium evaporator for driving the gas phase heat medium to evaporate and circulate; The liquid phase heat medium circuit includes a spiral coil arranged inside the mixing zone and a serpentine heating pipe arranged inside the viscosity increasing zone, and also includes a liquid phase heat medium pipeline for transporting liquid phase heat medium to the spiral coil and the serpentine heating pipe.

3. The horizontal prepolymerization reactor according to claim 2, wherein The gas phase heat medium in the gas phase heat medium circuit is a biphenyl-biphenyl ether mixture, and the operating temperature range is 270-290°C; The liquid phase heat medium in the liquid phase heat medium circuit is hydrogenated terphenyl, and the operating temperature range is 260-280°C.

4. The horizontal prepolymerization reactor according to claim 1, wherein: The number of the viscosity increasing zones is 3, and the height of the baffles decreases by 5%-15% of the liquid level along the material flow direction.

5. The horizontal prepolymerization reactor according to claim 1, characterized in that: A disc turbine agitator is provided in the viscosity increasing zone, and the diameter of the agitator blade increases gradually along the material flow direction.

6. The horizontal prepolymerization reactor according to claim 5, characterized in that: The diameter of the stirring blade increases gradually by 0.1-0.2 μm, thereby forming a 120-180s interval between adjacent viscosity-increasing zones. -1 shear rate gradient.

7. The horizontal prepolymerization reactor according to claim 1, characterized in that , It also includes an EG cleaning system, which includes an atomizing nozzle arranged at the top of the mixing zone, with an atomizing particle size of ≤100μm and a spray angle of ≥90°.

8. The horizontal prepolymerization reactor according to claim 7, characterized in that: The EG cleaning system is also connected to a pressure pump.

9. The horizontal prepolymerization reactor according to claim 1, characterized in that: The invention also includes a vacuum system for evacuating the horizontal kettle body, and a nitrogen protection device interlocked with the vacuum system.

10. The horizontal prepolymerization reactor according to claim 1, characterized in that: It also includes an intelligent controller connected to the dynamic heat medium distribution unit. The intelligent controller is based on the Elman neural network model, and outputs flow regulation instructions for the gas phase heat medium circuit and the liquid phase heat medium circuit by inputting parameters including material temperature, viscosity and vacuum degree.

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