Continuous reactor for the preparation of sodium azulenesulfonate

Abstract

The application discloses a continuous reactor for preparing sodium azulene sulfonate, and relates to the technical field of pharmaceutical equipment. The continuous reactor comprises a first cover, a low-temperature sulfonation section, a medium-temperature curing section, a constant-temperature stabilizing section and a second cover which are coaxially and detachably connected in sequence. A feeding distribution unit is clamped and installed between the first cover and the low-temperature sulfonation section. A synchronous mixing unit is arranged inside the reactor. An online monitoring and closed-loop control system is further provided. Three reaction chambers are separated by a partition and are overflowed and communicated through L-shaped material pipes. Independent temperature control units and inclined-blade turbine type mixing blades are arranged in the chambers. Wall scraping structures are arranged on the outer edges of the middle and rear blades. The continuous production of sodium azulene sulfonate is realized by adopting a three-stage serial continuous reaction architecture, cooperating with graded precise temperature control and intensified mass transfer stirring structures, the generation of side reactions is inhibited, and the product yield and purity are improved. The online monitoring control is combined to improve the product quality stability between batches, and the industrial large-scale production demand of pharmaceutical-grade sodium azulene sulfonate is met.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical equipment technology, and specifically to a continuous reactor for the preparation of sodium azulene sulfonate. Background Technology

[0002] Sodium azulene sulfonate is a widely used pharmaceutical active ingredient in clinical practice, commonly used to treat diseases such as gastritis, gastric ulcers, oral ulcers, and skin inflammation. It possesses anti-inflammatory and mucosal tissue repair-promoting pharmacological effects. Its core preparation process involves the sulfonation reaction of azulene guaiac. This sulfonation reaction is a strongly exothermic reaction and is extremely sensitive to reaction temperature and material mixing uniformity. If temperature runaway or local sulfonating agent concentration imbalance occurs during the reaction, it can easily trigger side reactions such as disulfonation and oxidative ring-opening, directly reducing product yield and purity, making it difficult to meet the stringent quality requirements of pharmaceutical-grade products.

[0003] Currently, the industrial production of sodium azulene sulfonate mostly uses batch reactors, where a single batch of material is fed, reacted, and then discharged for subsequent processes. This type of equipment has several unavoidable drawbacks: First, low production efficiency. Batch operation requires repeated feeding, heating, holding, cooling, and discharging, resulting in a high proportion of auxiliary processes and limited annual capacity per unit, making it difficult to support large-scale market demand. Second, poor product quality stability. The limited mass and heat transfer capacity of batch reactors makes it prone to localized overheating and uneven material concentration distribution within the reaction system, leading to increased by-product content. Product yield is typically only 65%–70%, and batch-to-batch purity deviations can exceed 1.5%, failing to consistently guarantee the quality uniformity of pharmaceutical-grade products. Third, low levels of automation and safety. Batch production heavily relies on manual parameter control, resulting in high operating costs and significant human error. Furthermore, manual intervention during strongly exothermic reactions poses significant safety risks.

[0004] Existing continuous reaction equipment, such as microchannel reactors, while enhancing mass transfer, generally suffers from low throughput, easy clogging of flow channels, and high maintenance costs. They are only suitable for small-scale reagent production and cannot meet the requirements of industrial-scale production of hundreds of tons. Conventional tubular continuous reactors mostly employ overall temperature control, which cannot match the segmented temperature requirements of sulfonation reactions—"low-temperature initiation, medium-temperature ripening, and constant-temperature stabilization"—and most lack online monitoring and automatic closed-loop control functions. Fluctuations in reaction parameters cannot be corrected in a timely manner, making it difficult to consistently guarantee product quality. Therefore, there is an urgent need to develop a continuous reaction device adapted to the sodium azulene sulfonate preparation process, possessing high production efficiency, high product purity, and a high level of automation. Summary of the Invention

[0005] To address the problems in the prior art, the present invention provides a continuous reactor for the preparation of sodium azulene sulfonate, which is achieved through the following technical solution.

[0006] A continuous reactor for preparing sodium azulene sulfonate includes a first cap, a low-temperature sulfonation section is provided on one side of the first cap, and a feed distribution unit is installed between the first cap and the low-temperature sulfonation section. One end of the low-temperature sulfonation section is connected to a medium-temperature curing section, and the other end of the medium-temperature curing section is connected to a constant-temperature stabilization section. The other end of the constant-temperature stabilization section is connected to a second cap. A synchronous mixing unit is provided inside the first cap, the low-temperature sulfonation section, the medium-temperature curing section, the constant-temperature stabilization section, the second cap, and the feed distribution unit. The low-temperature sulfonation section includes a first cylinder and a second mounting lock and a first lock head respectively disposed at both ends of the first cylinder. A first partition is disposed inside the first cylinder near the first lock head, and a first sealing sleeve is disposed at the center of the first partition. A first material passage pipe is installed on the first partition. The medium-temperature curing section includes a second cylinder and a third mounting lock and a second lock head respectively disposed at both ends of the second cylinder. A second partition is disposed inside the second cylinder near the end of the second lock head. A second sealing sleeve is disposed at the center of the second partition, and a second material passage pipe is installed on the second partition. The constant temperature stabilization section includes a third cylinder and a fourth mounting lock and a third lock head respectively disposed at both ends of the third cylinder. A discharge pipe is installed on the third cylinder, and a discharge slope is provided inside the third cylinder. The feeding and distributing unit includes a feeding and mixing tank and a discharge pipe connected to one end of the feeding and mixing tank, and the other end of the discharge pipe is connected to an annular feeding component. The feeding and mixing tank is provided with a first annular feeding pipe and a second annular feeding pipe, and a premixing component is provided inside the feeding and mixing tank. The synchronous mixing unit includes a main shaft and a first mixing section, a second mixing section and a third mixing section mounted on the main shaft. A first temperature control element is provided at the first mixing section, and a second temperature control element and a third temperature control element are respectively provided on one side of the second mixing section and the third mixing section.

[0007] Preferably, the annular fabric component includes an annular fabric tube and an installation port formed on the annular fabric tube, wherein the annular fabric tube is uniformly provided with fabric openings.

[0008] Preferably, the premixing component includes a first baffle and a second baffle, which are staggered together.

[0009] Preferably, the first baffle and the second baffle are both inclined, and all the inclination angles are the same.

[0010] Preferably, the first temperature control component includes a control component and a connecting pipe connected to one side of the control component, and a fixing ring is connected to the connecting pipe, and a temperature control pipe is connected to the fixing ring.

[0011] Preferably, a scraper is fixedly connected to the outer end of the second mixing section, and the internal structure of the second mixing section is the same as that of the third mixing section.

[0012] Preferably, the first cover is connected to an installation strip, and the installation strip passes through the installation socket and is fixedly connected to the second installation lock.

[0013] Preferably, a first mounting lock is connected to the second cover, and the first mounting lock is fixedly connected to the third lock head.

[0014] Preferably, it also includes an online monitoring and closed-loop control system; the online monitoring and closed-loop control system includes a temperature sensor, a pressure sensor, and a pH electrode respectively installed inside the low-temperature sulfonation section, the medium-temperature curing section, and the constant-temperature stabilization section, an online spectrophotometer connected in series on the discharge pipe, and a PLC control cabinet; the temperature sensor, pressure sensor, pH electrode, and online spectrophotometer are all electrically connected to the signal input terminal of the PLC control cabinet, and the signal output terminal of the PLC control cabinet is electrically connected to the feed metering pump, the main shaft drive, the temperature control valves of each temperature control component, and the throttling valve of the feed pipe, forming a fully closed-loop automatic control system.

[0015] Preferably, the temperature sensor, pressure sensor, and pH electrode are all explosion-proof detection elements, which are inserted into the central region of the chamber from the side wall of the corresponding cylinder; the online spectrophotometer detects the reaction conversion rate in real time through the characteristic absorption peak of the azurite ring.

[0016] The present invention has the following beneficial effects: 1. Utilizing a horizontal, three-stage, continuous reaction structure, materials are continuously fed from the beginning and sequentially pass through three chambers: low-temperature sulfonation, medium-temperature curing, and constant-temperature stabilization, completing the entire reaction process before continuous discharge. This eliminates the time losses associated with auxiliary processes such as feeding, discharging, and temperature adjustment inherent in traditional batch reactors. Furthermore, each stage of the reactor employs a lockable, detachable connection structure, facilitating easy assembly and disassembly, as well as internal maintenance, cleaning, and component replacement. The material flow resistance can be flexibly adjusted via an electric throttling valve on the feed pipe, allowing the total reaction residence time to be controlled within the range of 1.5–3 hours, adapting to different raw material concentrations and production loads.

[0017] 2. A three-stage independent temperature control system is implemented to address the kinetic characteristics of different stages of the sulfonation reaction. The temperatures of the low-temperature sulfonation stage, the medium-temperature ripening stage, and the isothermal stabilization stage are precisely controlled at 0~5℃, 15~20℃, and 20~25℃ respectively, creating a temperature gradient highly matched to the reaction process. This ensures the directional conduction of the reaction and reduces high-temperature side reactions and secondary sulfonation. Simultaneously, the inclined blade turbine structure of the synchronous mixing unit generates radial shear flow and axial circulating flow during rotation, enabling rapid and uniform mixing of materials within the chamber. This eliminates the problems of excessively high local sulfonating agent concentration and local overheating, further suppressing the formation of by-products.

[0018] 3. By setting up an online monitoring and closed-loop control system, the system collects various parameters of the reaction process and product conversion rate and purity data in real time through temperature, pressure, and pH detection elements in the three-stage chamber and an online spectrophotometer at the discharge end. The PLC control cabinet compares the real-time data with the preset process parameters and automatically adjusts the feed flow rate, stirring speed, heat exchange medium parameters, and material flow rate to achieve automated closed-loop control, completely eliminating human operation errors and ensuring that the reaction conditions are always stable within the optimal range. Attached Figure Description

[0019] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 : A schematic diagram of the overall structure of this invention; Figure 2 : A schematic diagram of the overall cross-sectional structure in this invention; Figure 3 : Exploded structural diagram of the first cap, low-temperature sulfonation section, medium-temperature curing section, constant-temperature stabilization section and second cap in this invention; Figure 4 : A schematic diagram of the feeding and dispensing unit in this invention; Figure 5 : A schematic cross-sectional view of the feed mixing tank in this invention; Figure 6 : A schematic diagram of the synchronous mixing unit in this invention; Figure 7 : A schematic diagram of the connection structure between the main shaft, the first mixing section, and the first temperature control element in this invention; Figure 8 : A schematic diagram of the structure of the first temperature control element in this invention; Figure 9 : A schematic diagram of the structure of the second mixing section in this invention.

[0021] The attached figures are labeled as follows: 1. First cover; 11. Mounting strip; 2. Low-temperature sulfonation section; 21. First cylinder; 22. Second mounting lock; 23. First lock head; 24. First partition plate; 25. First sealing sleeve; 26. First feed pipe; 3. Medium-temperature curing section; 31. Second cylinder; 32. Third mounting lock; 33. Second lock head; 34. Second partition plate; 35. Second sealing sleeve; 36. Second material conveying pipe; 4. Constant temperature stabilization section; 41. Third cylinder; 42. Fourth mounting lock; 43. Third lock head; 44. Discharge pipe; 45. Discharge slope; 5. Second cover; 51. First installation lock; 6. Feeding and distributing unit; 61. Feeding and mixing tank; 62. Discharge pipe; 63. Annular feeding component; 631. Annular feeding pipe; 632. Mounting port; 633. Uniform feeding port; 64. First annular feeding pipe; 65. Second annular feeding pipe; 66. Premixing component; 661. First baffle; 662. Second baffle; 7. Synchronous mixing unit; 71. Main shaft; 72. First mixing section; 73. First temperature control element; 731. Control element; 732. Connecting pipe; 733. Fixed ring seat; 734. Temperature control pipe; 74. Second mixing section; 741. Scraper; 75. Third mixing section; 76. Second temperature control element; 77. Third temperature control element. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] Reference Figures 1-9 As shown in the first embodiment of the present invention, a continuous reactor for the preparation of sodium azulene sulfonate is provided, comprising a first cap 1, a low-temperature sulfonation section 2, a medium-temperature curing section 3, a constant-temperature stabilization section 4, and a second cap 5 connected coaxially in sequence. A feed distribution unit 6 is installed between the first cap 1 and the low-temperature sulfonation section 2. A synchronous mixing unit 7 is installed through the reactor. The reactor is also equipped with an online monitoring and closed-loop control system.

[0025] The low-temperature sulfonation section 2 includes a first cylinder 21. A second mounting lock 22 is provided at one end of the first cylinder 21 near the first cover 1, and a first lock head 23 is provided at the other end. A first partition 24 is fixedly provided inside the first cylinder 21 near the first lock head 23. A first sealing sleeve 25 is embedded in the center of the first partition 24. A first feed pipe 26 is installed at the eccentric position of the first partition 24. The first feed pipe 26 is an L-shaped bend. Its inlet end is located at the upper liquid level of the inner cavity of the first cylinder 21, and its outlet end extends to the lower region of the medium-temperature curing section 3. An electric throttling regulating valve can be installed on the first feed pipe 26 to adjust the feed resistance.

[0026] The intermediate-temperature curing section 3 includes a second cylinder 31. A third mounting lock 32 is provided at one end of the second cylinder 31 near the low-temperature sulfonation section 2, and a second lock head 33 is provided at the other end. A second partition 34 is fixedly provided inside the second cylinder 31 near the second lock head 33. A second sealing sleeve 35 is embedded in the center of the second partition 34. A second feed pipe 36 is installed at the eccentric position of the second partition 34. The structure of the second feed pipe 36 is the same as that of the first feed pipe 26, and it is used to connect the intermediate-temperature curing section 3 and the constant-temperature stabilization section 4.

[0027] The constant temperature stabilization section 4 includes a third cylinder 41. A fourth mounting lock 42 is provided at one end of the third cylinder 41 near the medium temperature ripening section 3, and a third lock head 43 is provided at the other end. A discharge pipe 44 is installed on the lower side wall of the third cylinder 41, and a discharge slope 45 is provided on the inner bottom wall of the third cylinder 41. The discharge slope 45 is inclined towards the discharge pipe 44 to facilitate the smooth discharge of the material after the reaction is completed.

[0028] The inner side of the second cover 5 is provided with a first mounting lock 51, and the first mounting lock 51 and the third lock head 43 are detachably fixedly connected by a threaded or snap-fit ​​structure.

[0029] The feeding and distributing unit 6 includes a feeding mixing tank 61, one end of which is connected to a discharge pipe 62, and the other end of the discharge pipe 62 is connected to an annular feeding component 63. A first annular feeding pipe 64 and a second annular feeding pipe 65 are provided on the side wall of the feeding mixing tank 61, for respectively introducing guaiac organic solution and sulfonating agent materials. A premixing component 66 is provided inside the feeding mixing tank 61. Further, the annular feeding component 63 includes an annular feeding pipe 631, which has an installation socket 632 adapted to the mounting strip 11. Multiple uniform feeding ports 633 are evenly distributed on the end face of the annular feeding pipe 631, with the opening direction of the uniform feeding ports 633 facing the inner cavity side wall of the low-temperature sulfonation section 2, so that the fed material is evenly diffused into the cavity. The premixing component 66 includes multiple sets of staggered first baffles 661 and second baffles 662. The first baffles 661 and the second baffles 662 are both inclined and have the same inclination angle. When the material flows through, it achieves preliminary dispersion and mixing through the cutting and deflection effect of the baffles.

[0030] At least two mounting strips 11 are fixedly connected to the inner side of the first cover 1. The mounting strips 11 pass through the mounting sockets 632 on the annular fabric tube 631 and are fixedly connected to the second mounting lock 22 at their ends, thereby clamping and fixing the annular fabric piece 63 between the first cover 1 and the low-temperature sulfonation section 2. The first lock head 23 and the third mounting lock 32, the second lock head 33 and the fourth mounting lock 42, and the third lock head 43 and the first mounting lock 51 are all connected by a detachable locking structure, so that the first cover 1, the low-temperature sulfonation section 2, the medium-temperature curing section 3, the constant temperature stabilization section 4, the second cover 5 and the feed distribution unit 6 are spliced ​​into a sealed integral reactor shell.

[0031] The synchronous mixing unit 7 includes a main shaft 71, which runs through the reactor axis. A first mixing section 72, a second mixing section 74, and a third mixing section 75 are sequentially fixedly mounted on the main shaft 71. The first mixing section 72 is located within the cavity of the low-temperature sulfonation section 2, the second mixing section 74 is located within the cavity of the medium-temperature ripening section 3, and the third mixing section 75 is located within the cavity of the constant-temperature stabilization section 4. A first temperature control element 73 is provided at the first mixing section 72, a second temperature control element 76 is provided on one side of the second mixing section 74, and a third temperature control element 77 is provided on one side of the third mixing section 75. Furthermore, the first temperature control element 73 includes a control element 731, which is located outside the reactor. A connecting pipe 732 is connected to one side of the control element 731. The connecting pipe 732 extends into the inner cavity of the reactor and is connected to a fixed ring seat 733. Two sets of fixed ring seats 733 are provided, both of which are sealed and rotatably mounted on the main shaft 71. A temperature control pipe 734 is connected between the two sets of fixed ring seats 733. The temperature control pipe 734 rotates synchronously with the main shaft 71. A rotary sealing structure is provided between the connecting pipe 732 and the fixed ring seat 733, so that the external heat exchange medium can pass through the control element 731 and the connecting pipe 732 into the temperature control pipe 734, thereby achieving precise temperature control of the low-temperature sulfonation section 2. The first mixing section 72, the second mixing section 74, and the third mixing section 75 have the same internal structure, all employing a 6-blade 45° inclined turbine propeller structure. A scraper 741 is fixedly connected to the outer end of the second mixing section 74, and a scraper structure is also provided on the third mixing section 75. The gap between the outer edge of the scraper 741 and the inner wall of the corresponding cylinder is 5-8 mm. A polytetrafluoroethylene scraper strip is embedded in the outer edge of the scraper 741 to scrape off material adhering to the inner wall of the cylinder. The second temperature control element 76 is fixedly installed on the second partition 34, located in the inner cavity of the medium-temperature curing section 3. The third temperature control element 77 is fixedly installed on the inner side of the second cover 5, located in the inner cavity of the constant-temperature stabilization section 4. Both the second temperature control element 76 and the third temperature control element 77 can adopt a shell-and-tube heat exchange structure, independently connected to an external constant-temperature medium circulation system, to achieve independent temperature control of the medium-temperature curing section and the constant-temperature stabilization section.

[0032] One end of the main shaft 71 extends through the second cover 5 and is connected to the servo drive motor via a coupling. A mechanical seal structure is provided at the extension position. The first sealing sleeve 25 and the second sealing sleeve 35 are both fitted on the main shaft 71 to achieve dynamic sealing between the partition and the main shaft, thus preventing material cross-flow between the chambers.

[0033] Example 2

[0034] Combination Figures 1-9 As shown, this is the second embodiment of the present invention, which, based on embodiment 1, details the working steps and processing flow of the device as follows: S1. Equipment Assembly and Debugging: Separate the first cover 1, feed distribution unit 6, low-temperature sulfonation section 2, medium-temperature curing section 3, constant temperature stabilization section 4, and second cover 5 into a locking structure for sealing. Install the synchronous mixing unit 7 into the reactor and connect it to the servo drive motor. Connect the first annular feed pipe 64 and the second annular feed pipe 65 to the raw material storage tank through precision metering pumps. Connect each temperature control component to the corresponding constant temperature medium circulation system to complete the equipment assembly and debugging.

[0035] S2. Continuous feeding and premixing: Two precision metering pumps are started to continuously feed the two materials into the feeding mixing tank 61 according to the set molar ratio. The materials flow through the first baffle 661 and the second baffle 662 arranged in a staggered manner in the feeding mixing tank 61. The materials are initially dispersed and mixed through the baffle cutting and turbulent reversal effect to avoid excessive local concentration of sulfonating agent. The premixed materials enter the annular distribution pipe 631 through the feed pipe 62 and are evenly sprayed into the inner cavity of the low temperature sulfonation section 2 through multiple uniform distribution ports 633 to eliminate the interference of feeding impact on the reaction flow field.

[0036] S3. Low-temperature sulfonation-initiated reaction: The servo drive motor is started, driving the main shaft 71 to rotate at a set speed. The speed can be steplessly adjusted within the range of 0~600rpm. The inclined blade turbine of the first mixing section 72 rotates with the main shaft, generating radial shear flow and axial circulating flow, so that the material is fully mixed and transferred. At the same time, the first temperature control element 73 introduces a low-temperature ethylene glycol aqueous solution, which precisely controls the reaction temperature in the low-temperature sulfonation section 2 at 0~5℃, so that the guaiac wood and the sulfonating agent undergo a directional monosulfonation reaction in a low-temperature environment, and the generation of high-temperature side reactions is suppressed.

[0037] S4. Medium-temperature curing improves conversion rate: The material after low-temperature sulfonation overflows into the medium-temperature curing section 3 through the first feed pipe 26; the second mixing section 74 rotates synchronously with the main shaft, continuously stirring the material to enhance mass transfer; the scraper 741 scrapes along the inner wall of the second cylinder 31 to prevent high-viscosity reactants from scaling and depositing; the second temperature control element 76 introduces constant-temperature water to control the temperature of the medium-temperature curing section 3 at 15~20℃, so that the sulfonation reaction can proceed fully and improve the reaction conversion rate.

[0038] S5. Constant Temperature Stable Product Structure: The matured material overflows into the constant temperature stabilization section 4 through the second feed pipe 36; the third mixing section 75 continuously stirs to ensure uniform material temperature, and the third temperature control element 77 stably controls the chamber temperature at 20~25℃, so as to stabilize the reaction product structure and avoid product decomposition or secondary sulfonation; the stabilized material is collected along the feed slope 45 and continuously discharged from the reactor through the discharge pipe 44 to enter the subsequent rapid cooling and neutralization process.

[0039] S6. Residence Time Adjustment: By adjusting the opening of the electric throttling valve on the first feed pipe 26 and the second feed pipe 36, the material flow resistance can be changed, thereby adjusting the liquid level and material residence time in each chamber. The total reaction residence time can be flexibly adjusted within the range of 1.5 to 3 hours to adapt to the production needs of different raw material concentrations and production loads.

[0040] Example 3

[0041] Combination Figures 1-9 As shown, this is the third embodiment of the present invention, which, based on embodiments 1 and 2, details the online monitoring and closed-loop control system of the equipment as follows: The online monitoring and closed-loop control system includes temperature sensors, pressure sensors, and pH electrodes respectively inserted into the chambers of the low-temperature sulfonation section 2, the medium-temperature curing section 3, and the constant-temperature stabilization section 4; an online spectrophotometer connected in series on the discharge pipe 44; and a PLC control cabinet arranged in the operating area next to the reactor. All detection elements adopt an explosion-proof structure to meet the explosion-proof requirements of chemical and pharmaceutical production.

[0042] Temperature, pressure, and pH sensors are inserted into the central area of ​​the chamber from the side wall of the corresponding cylinder to collect real-time data on reaction temperature, pressure, and pH value of the material in each chamber. An online spectrophotometer is connected in series on the discharge pipe 44 to detect the reaction conversion rate and product purity of the discharged material in real time through the characteristic absorption peak of the azurite ring.

[0043] The signal output terminals of all detection elements are connected to the signal input terminals of the PLC control cabinet. The signal output terminals of the PLC control cabinet are respectively connected to the feed precision metering pump, servo drive motor, temperature control valves of each temperature control component, and electric throttle valves of the feed pipe, forming a fully closed-loop automatic control system.

[0044] When the system is working, the PLC control cabinet compares the various reaction parameters collected in real time with the preset optimal process parameters. When the parameters deviate, it automatically outputs control signals for adjustment: when the chamber temperature deviates from the set value, it adjusts the heat exchange medium flow rate and temperature of the corresponding temperature control element to bring the temperature back to the set range; when the reaction conversion rate is lower than the preset value, it appropriately reduces the feed flow rate, extends the reaction residence time, or increases the stirring speed to enhance mass transfer; when the pH value of the material fluctuates abnormally, it adjusts the proportioning parameters of the feed metering pump to ensure the stability of the raw material molar ratio.

[0045] The PLC control cabinet has a built-in over-limit alarm module and interlock shutdown module. When parameters such as reaction temperature and pressure exceed the safety threshold, the system immediately triggers an audible and visual alarm and automatically performs load reduction or interlock shutdown operations according to the over-limit level, avoiding the risk of runaway due to strong exothermic sulfonation and improving production safety.

[0046] Through fully closed-loop online monitoring and control, human error can be completely eliminated, ensuring that reaction conditions remain stable within the optimal range. This allows the purity deviation between batches to be controlled within ±0.1%, improving product quality consistency while reducing manual operation costs.

[0047] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A continuous reactor for the preparation of sodium azulene sulfonate, comprising a first cap (1), characterized in that, A low-temperature sulfonation section (2) is provided on one side of the first cover (1), and a feeding distribution unit (6) is installed between the first cover (1) and the low-temperature sulfonation section (2). One end of the low-temperature sulfonation section (2) is connected to a medium-temperature curing section (3), and the other end of the medium-temperature curing section (3) is connected to a constant temperature stabilization section (4). The other end of the constant temperature stabilization section (4) is connected to a second cover (5). A synchronous mixing unit (7) is provided inside the first cover (1), the low-temperature sulfonation section (2), the medium-temperature curing section (3), the constant temperature stabilization section (4), the second cover (5), and the feeding distribution unit (6). The low-temperature sulfonation section (2) includes a first cylinder (21) and a second mounting lock (22) and a first lock head (23) respectively disposed at both ends of the first cylinder (21). A first partition (24) is disposed inside the first cylinder (21) near the first lock head (23), and a first sealing sleeve (25) is disposed at the center of the first partition (24). A first feed pipe (26) is installed on the first partition (24). The medium-temperature curing section (3) includes a second cylinder (31) and a third mounting lock (32) and a second lock head (33) respectively disposed at both ends of the second cylinder (31). A second partition (34) is disposed inside the second cylinder (31) near the second lock head (33). A second sealing sleeve (35) is disposed at the center of the second partition (34). A second material passage pipe (36) is installed on the second partition (34). The constant temperature stabilization section (4) includes a third cylinder (41) and a fourth mounting lock (42) and a third lock head (43) respectively disposed at both ends of the third cylinder (41). A discharge pipe (44) is installed on the third cylinder (41), and a discharge slope (45) is provided inside the third cylinder (41). The feeding and distributing unit (6) includes a feeding mixing tank (61) and a discharge pipe (62) connected to one end of the feeding mixing tank (61), and the other end of the discharge pipe (62) is connected to an annular fabric distribution member (63). The feeding mixing tank (61) is provided with a first annular feeding pipe (64) and a second annular feeding pipe (65), and a premixing member (66) is provided inside the feeding mixing tank (61). The synchronous mixing unit (7) includes a main shaft (71) and a first mixing section (72), a second mixing section (74) and a third mixing section (75) mounted on the main shaft (71). A first temperature control element (73) is provided at the first mixing section (72), and a second temperature control element (76) and a third temperature control element (77) are respectively provided on one side of the second mixing section (74) and the third mixing section (75).

2. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The annular fabric component (63) includes an annular fabric tube (631) and an installation port (632) opened on the annular fabric tube (631). The annular fabric tube (631) is evenly provided with uniform fabric openings (633).

3. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The premixing component (66) includes a first baffle (661) and a second baffle (662), which are staggered.

4. The continuous reactor for preparing sodium azulene sulfonate according to claim 3, characterized in that, The first baffle (661) and the second baffle (662) are both inclined, and all the inclination angles are the same.

5. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The first temperature control element (73) includes a control element (731) and a connecting pipe (732) connected to one side of the control element (731), and a fixed ring seat (733) is connected to the connecting pipe (732), and a temperature control pipe (734) is connected to the fixed ring seat (733).

6. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The outer end of the second mixing section (74) is fixedly connected to a scraper (741), and the internal structure of the second mixing section (74) is the same as that of the third mixing section (75).

7. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The first cover (1) is connected to an installation strip (11), and the installation strip (11) passes through the installation socket (632) and is fixedly connected to the second installation lock (22).

8. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, The second cover (5) is connected to a first mounting lock (51), and the first mounting lock (51) is fixedly connected to the third lock head (43).

9. The continuous reactor for preparing sodium azulene sulfonate according to claim 1, characterized in that, It also includes an online monitoring and closed-loop control system; the online monitoring and closed-loop control system includes a temperature sensor, a pressure sensor, and a pH electrode respectively installed in the low-temperature sulfonation section (2), the medium-temperature curing section (3), and the constant temperature stabilization section (4), an online spectrophotometer connected in series on the discharge pipe (44), and a PLC control cabinet; the temperature sensor, pressure sensor, pH electrode, and online spectrophotometer are all electrically connected to the signal input terminal of the PLC control cabinet, and the signal output terminal of the PLC control cabinet is electrically connected to the feed metering pump, the main shaft drive, the temperature control valve of each temperature control component, and the throttle valve of the feed pipe, forming a fully closed-loop automatic control system.

10. The continuous reactor for preparing sodium azulene sulfonate according to claim 9, characterized in that, The temperature sensor, pressure sensor, and pH electrode are all explosion-proof detection elements, which are inserted into the central region of the chamber from the side wall of the corresponding cylinder; the online spectrophotometer detects the reaction conversion rate in real time through the characteristic absorption peak of the azurite ring.

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