Reaction kettle for preparing p-hydroxybenzoic acid with mixing mechanism

Abstract

The application relates to the technical field of reaction kettles, and discloses a reaction kettle with a mixing mechanism for preparing p-hydroxybenzoic acid, which comprises a rack, a support frame fixedly installed on the rack, two groups of support frames, a kettle body fixedly installed between the two groups of support frames, a kettle cover fixedly installed at the top of the kettle body, and a mixing assembly arranged on the kettle body. The asynchronous motor drives the rotating shaft to drive the driving gear to rotate, thereby driving the meshed driven gear to drive the rotating rod, the rotating rod drives the mixing shaft, the mixing paddle and the bottom paddle to rotate synchronously, the kettle cover and the feeding port continuously feed, the discharge port discharges the finished product, the rack and the support frame stably support the kettle body, the jacket passes in hot air through the air inlet and discharges the hot air through the air outlet to control the temperature, so that the material is fully mixed, the materials accumulated at the bottom of the kettle are eliminated, and the reaction conversion rate of the p-hydroxybenzoic acid is improved.

Description

Technical Field

[0001] This invention relates to the field of reaction vessel technology, specifically to a reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism. Background Technology

[0002] p-Hydroxybenzoic acid is an important organic synthesis intermediate, widely used in the production of chemical products such as pharmaceuticals, fragrances, and preservatives. Its main preparation process involves neutralizing phenol with potassium hydroxide to produce potassium phenolate, followed by heating, dehydration, and carboxylation to synthesize the final product. This process relies entirely on a reactor to complete material mixing, temperature control, and phase transformation. The mixing performance, temperature control accuracy, and material homogenization effect of the reactor directly determine the reaction conversion rate and product purity of p-hydroxybenzoic acid.

[0003] In the existing technology, the reaction vessel used for the preparation of p-hydroxybenzoic acid mostly adopts a single shaft stirring structure. The entire equipment relies on the frame and support frame to support the vessel body. The stirring shaft and stirring paddle driven by the motor directly stir and mix the phenol and potassium hydroxide raw materials put into the vessel body. The jacket outside the vessel body introduces hot gas to achieve overall temperature control. The materials complete the neutralization, dehydration and carboxylation reactions inside the vessel body. After the reaction is completed, the finished product is discharged from the bottom outlet of the vessel, thus completing the batch preparation of p-hydroxybenzoic acid.

[0004] In actual use, existing conventional reaction vessels still have many shortcomings: First, existing equipment relies on a single stirring structure inside the vessel to mix materials without a pre-mixing structure. Phenol and potassium hydroxide have large differences in density and polarity, and direct addition to the vessel can easily cause material stratification, resulting in insufficient neutralization reaction, poor initial material homogenization, and reduced efficiency of subsequent carboxylation reaction. Secondly, conventional stirring structures can only form a single circumferential material flow field. The material flow at the bottom of the vessel is poor, which easily leads to sedimentation, material retention, dead zones in material mixing, and insufficient reaction uniformity, directly affecting the overall reaction conversion rate of p-hydroxybenzoic acid. Third, during the premixing and reaction of raw materials, phenol is prone to oxidation reaction with oxygen in the air to generate colored impurities. In addition, the flow field of the reaction system is singular, and the contact between carbon dioxide and potassium phenolate is insufficient, which easily generates salicylic acid byproduct and reduces the purity of the finished product. Fourth, existing equipment lacks precise premixing temperature control and airflow disturbance auxiliary structures, resulting in poor controllability of premixing reaction temperature. Furthermore, the lack of inert gas protection structures leads to frequent material agglomeration, further exacerbating reaction defects and fluctuations in finished product quality.

[0005] In view of this, we propose a reaction vessel with a mixing mechanism for the preparation of p-hydroxybenzoic acid. Summary of the Invention

[0006] The purpose of this invention is to provide a reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism includes a frame, on which a support frame is fixedly mounted. Two sets of support frames are provided, and a vessel body is fixedly mounted between the two sets of support frames. A vessel cover is fixedly mounted on the top of the vessel body, and the vessel cover is provided with multiple sets of feed ports. A discharge port is provided at the center of the bottom end of the vessel body. A jacket is spirally fitted to the outside of the vessel body. A mixing component is provided on the vessel body. The mixing component includes an asynchronous motor that operates intermittently in both forward and reverse directions, resulting in better mixing effect. The asynchronous motor is fixedly installed on the lower surface of the top of the frame. Inside the top of the frame, a rotating shaft and a rotating rod are rotatably installed via bearing components. The output end of the asynchronous motor is fixedly connected to the bottom end of the rotating shaft. A driving gear is fixedly installed on the outside of the rotating shaft, and a driven gear is fixedly installed on the outside of the rotating rod. The driving gear meshes with the driven gear. A bearing seat is fixedly installed at the center of the top of the vessel lid. The rotating rod is rotatably installed on the bearing seat. A mixing shaft is fixedly installed at the bottom of the rotating rod via fasteners. Two sets of vertically aligned mixing paddles are fixedly installed on the outside of the mixing shaft. A V-shaped bottom paddle is fixedly installed at the bottom of the mixing shaft to improve the mixing effect and adapt to the arc-shaped structure at the bottom of the vessel body.

[0008] In a further embodiment, the vessel lid is also provided with an observation window to facilitate observation of the reaction status.

[0009] In a further embodiment, multiple sets of feed inlets are respectively connected to the output end of the corresponding feeding equipment, and the discharge outlet is connected to the input end of the mixture collection equipment, which facilitates the input of multiple raw materials and the collection of the mixture after reaction.

[0010] In a further embodiment, the jacket input end is provided with an air inlet for connecting to the output end of the hot gas supply equipment via a pipeline. A temperature sensor is installed on this pipeline to adjust the reaction temperature by controlling the output power of the equipment. The jacket output end is provided with an air outlet for connecting to the input end of the hot gas recovery equipment via a pipeline.

[0011] In a further embodiment, a stirring assembly is provided on the frame. The stirring assembly includes a stirring drum, which is fixedly installed inside the top side wall of the frame. A drum cover is fixedly installed at the top of the stirring drum, and the drum cover is provided with a feeding port and an exhaust port. The bottom output end of the stirring drum is fixedly connected to the top of a discharge pipe, and the bottom end of the discharge pipe is fixedly installed inside the side wall of the bearing seat. A through groove is opened inside the side wall of the bearing seat, and the discharge pipe is connected to the inside of the through groove to facilitate the conveying of the pre-stirred mixture into the reactor body.

[0012] In a further embodiment, a cylinder is rotatably mounted inside the top of the frame via bearing components. A stirring rod is fixedly mounted at the bottom of the cylinder. Multiple sets of stirring paddles are fixedly mounted outside the stirring rod. The stirring paddles are T-shaped. An auxiliary gear is fixedly mounted outside the top of the cylinder. The auxiliary gear meshes with the driven gear. The area of ​​the circular cross-section of the auxiliary gear is smaller than that of the driven gear, thereby accelerating the cylinder.

[0013] In a further embodiment, the stirring drum is equipped with an auxiliary component, which includes an input connector and an output connector. The input connector and the output connector are respectively located on both sides of the bottom of the stirring drum. A spiral tube is fixedly installed between one end of the input connector and the output connector, and the other end of the input connector and the output connector is electrically connected to a heating device. The spiral tube is located outside the stirring paddle and the two do not intersect. The top of the cylinder is rotatably installed inside the output end of the bent tube through a sealed bearing. Multiple sets of through-holes are opened on the arc-shaped sidewall of the stirring rod. The cylinder, the stirring rod, and the bent tube are internally connected, thereby improving the pre-stirring effect through airflow disturbance.

[0014] In a further embodiment, the input end of the bend is connected to the output end of the inert gas supply device, and the output end of the exhaust port is connected to the input end of the waste gas recovery device.

[0015] In a further embodiment, a flow-disrupting component is provided inside the vessel body. The flow-disrupting component includes a conical shroud, which is conical in shape. Multiple sets of equally spaced circularly arranged arc-shaped strips are fixedly installed on the arc-shaped outer wall at the top of the conical shroud. The conical shroud is located between the through groove and the fastener. An installation block is fixedly installed on the arc-shaped inner wall of the vessel body. A vertical plate is fixedly installed on the installation block. Multiple sets of installation blocks and vertical plates are provided and are arranged in an equally spaced circular array. Multiple sets of horizontal grooves are opened on a single vertical plate. The mixing paddle does not intersect with the vertical plate to avoid motion interference.

[0016] In a further embodiment, one-way solenoid valves are installed on the pipelines connecting the feed inlet, discharge outlet, air inlet, air outlet, feed port, and exhaust outlet, as well as on the discharge pipe and bend, to facilitate the control of the transport of the medium inside the corresponding pipelines and prevent backflow.

[0017] Compared with the prior art, the present invention provides a reaction vessel for the preparation of p-hydroxybenzoic acid with a mixing mechanism, which has the following beneficial effects: 1. This reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism improves the uniformity of material mixing inside the vessel and prevents material accumulation at the bottom. It uses an asynchronous motor to drive a rotating shaft, which in turn drives a driven gear to rotate. The rotating shaft drives a mixing shaft, a mixing paddle, and a bottom paddle to rotate synchronously. The vessel lid and inlet continuously feed material, while the outlet discharges the finished product. The vessel body is stably supported by a frame and a support frame. The jacket allows hot air to enter through the inlet and exit through the outlet to control the temperature. This achieves all-round mixing of materials, eliminates material residue at the bottom of the vessel, and improves the conversion rate of p-hydroxybenzoic acid.

[0018] 2. This reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism involves the neutralization of phenol and KOH to produce potassium phenolate. Since the two react significantly in density and polarity, direct addition to the vessel would easily cause stratification. By shearing and fully neutralizing within a stirring drum, a uniform potassium phenolate solution is pre-formed and then transported to the vessel for heating, dehydration, and carboxylation. Specifically, a stirring assembly is installed, and the raw materials to be premixed are fed into the stirring drum through the feed port at the top of the drum cover. The auxiliary gear and driven gear on the cylinder mesh and rotate synchronously (are accelerated), driving the stirring rod and paddle to premix the materials inside the drum. The premixed material is then discharged into the vessel through a discharge pipe and a slot on the bearing seat. Exhaust gas generated during premixing is discharged through the exhaust port, thus homogenizing the materials in advance and improving the mixing effect.

[0019] 3. In order to introduce inert gas into the stirring tank, enhance the premixing effect by utilizing airflow disturbance, and promptly discharge the reaction waste gas, the spiral tube is first heated through the input and output connectors of the auxiliary components to control the premixing temperature. At the same time, the inert gas is introduced into the cylinder and stirring rod through the bend and dispersed from the gas outlet. The airflow forms turbulence in the gap between the stirring blades, and the waste gas in the cylinder is discharged outward through the exhaust port of the cylinder cover. Thus, the material agglomeration is broken by gas phase disturbance, while achieving inert atmosphere protection and reducing the generation of colored impurities from phenol oxidation.

[0020] 4. This reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism has a vertical plate fixed to the inner wall of the vessel by a mounting block of a flow-dispersing component inside the vessel. The vertical plate has multiple sets of horizontal grooves to divert the material, resulting in better mixing. At the same time, a conical hood with arc-shaped strips is arranged below the channel. The conical hood is driven by the mixing shaft to rotate synchronously, guiding and dispersing the premixed material. The conical hood also blocks and protects the fasteners, thereby transforming the circumferential flow field into three-dimensional turbulence, improving the contact efficiency between CO2 and potassium phenolate solid phase, reducing the formation of salicylic acid byproducts, and resulting in better mixing and stirring. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of a portion of the structure from another perspective of the present invention; Figure 3 For the present invention Figure 2 Enlarged structural diagram of region A in the middle; Figure 4 This is a first-view schematic diagram of a partial cross-sectional view of the structure of the present invention; Figure 5 This is a schematic diagram of a cross-sectional view of part of the structure of the present invention from a second perspective; Figure 6 This is a schematic diagram of the cross-section of the cylinder of the present invention; Figure 7 This is a cross-sectional schematic diagram of a portion of the stirring assembly of the present invention; Figure 8 This is a cross-sectional schematic diagram of a portion of the hybrid component structure of the present invention; Figure 9 For the present invention Figure 8 Enlarged structural diagram of region B in the middle; Figure 10 This is a cross-sectional schematic diagram of the hybrid component structure from another perspective of the present invention.

[0022] Explanation of icon numbers: 1. Frame; 2. Support frame; 31. Reactor body; 32. Reactor cover; 33. Feed inlet; 34. Discharge outlet; 35. Observation window; 41. Jacket; 42. Air inlet; 43. Air outlet; 5. Mixing assembly; 51. Asynchronous motor; 52. Rotary shaft; 53. Drive gear; 54. Rotating rod; 55. Driven gear; 56. Bearing housing; 57. Mixing shaft; 58. Mixing paddle; 59. Bottom paddle; 6. Stirring assembly; 61. Stirring 62. Cylinder; 63. Cylinder cover; 64. Feed port; 65. Vent port; 66. Discharge pipe; 67. Cylindrical cylinder; 68. Stirring rod; 69. Stirring paddle; 610. Auxiliary gear; 71. Through groove; 72. Auxiliary component; 73. Input connector; 74. Output connector; 75. Spiral tube; 76. Bend; 77. Vent hole; 88. Baffle component; 81. Conical cover; 82. Arc strip; 83. Mounting block; 84. Vertical plate; 85. Horizontal groove. Detailed Implementation

[0023] 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.

[0024] In this application, the term "above" indicates the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is primarily used to better describe this application and its embodiments, and is not intended to limit the indicated device, element, or component to having a specific orientation, or to construct and operate in a specific orientation. Furthermore, the term "above" may also be used in certain circumstances to indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0025] Please see Figures 1-10 The present invention provides a technical solution: A reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism includes a frame 1, on which a support frame 2 is fixedly mounted. Two sets of support frames 2 are provided, and a vessel body 31 is fixedly mounted between the two sets of support frames 2. A vessel cover 32 is fixedly mounted on the top of the vessel body 31, and the vessel cover 32 has multiple sets of feed inlets 33. A discharge outlet 34 is located at the center of the bottom end of the vessel body 31. A jacket 41 is spirally fitted to the outside of the vessel body 31. A mixing component 5 is mounted on the vessel body 31, including an asynchronous motor 51 that operates intermittently in both forward and reverse directions for better mixing. The asynchronous motor 51 is fixedly mounted on the lower surface of the top of the frame 1, and the top of the frame 1 is connected by bearing components. The rotating shaft 52 and rotating rod 54 are rotatably mounted. The output end of the asynchronous motor 51 is fixedly connected to the bottom end of the rotating shaft 52. The rotating shaft 52 is fixedly mounted with a drive gear 53, and the rotating rod 54 is fixedly mounted with a driven gear 55. The drive gear 53 meshes with the driven gear 55. The top center of the lid 32 is fixedly mounted with a bearing seat 56, and the rotating rod 54 is rotatably mounted on the bearing seat 56. The bottom of the rotating rod 54 is fixedly mounted with a mixing shaft 57 by fasteners. Two sets of vertically aligned mixing paddles 58 are fixedly mounted on the outside of the mixing shaft 57. The bottom of the mixing shaft 57 is fixedly mounted with a V-shaped bottom paddle 59, which improves the mixing effect and is compatible with the arc-shaped structure at the bottom of the lid 31.

[0026] In one embodiment of the present invention, an observation window 35 is also provided on the lid 32 to facilitate observation of the reaction state. In addition, multiple sets of feed ports 33 are respectively connected to the output end of the corresponding feeding equipment, and the discharge port 34 is connected to the input end of the mixture collection equipment to facilitate the input of various raw materials and the collection of the mixture after reaction. In addition, the input end of the jacket 41 is provided with an air inlet 42 for connecting to the output end of the hot gas supply equipment. A temperature sensor is provided on this pipe to adjust the reaction temperature by controlling the output power of the equipment. The output end of the jacket 41 is provided with an air outlet 43 for connecting to the input end of the hot gas recovery equipment.

[0027] In one embodiment of the present invention, a stirring assembly 6 is provided on the frame 1. The stirring assembly 6 includes a stirring drum 61, which is fixedly installed inside the top side wall of the frame 1. A drum cover 62 is fixedly installed on the top of the stirring drum 61. The drum cover 62 is provided with a feeding port 63 and an exhaust port 64. The bottom output end of the stirring drum 61 is fixedly connected to the top of a discharge pipe 65. The bottom end of the discharge pipe 65 is fixedly installed inside the side wall of a bearing seat 56. A through groove 610 is opened inside the side wall of the bearing seat 56. The discharge pipe 65 and the through groove 610 are connected. The internal components of the frame 1 are interconnected, facilitating the transport of pre-mixed materials to the interior of the vessel body 31. Additionally, a cylinder 66 is rotatably mounted inside the top of the frame 1 via bearing components. A stirring rod 67 is fixedly mounted at the bottom of the cylinder 66, and four sets of stirring paddles 68 are fixedly mounted on the outside of the stirring rod 67. The stirring paddles 68 are T-shaped. An auxiliary gear 69 is fixedly mounted on the outside of the top of the cylinder 66. The auxiliary gear 69 meshes with the driven gear 55. The area of ​​the circular cross-section of the auxiliary gear 69 is smaller than that of the driven gear 55, thereby accelerating the cylinder 66.

[0028] In one embodiment of the present invention, an auxiliary component 7 is provided on the stirring drum 61. The auxiliary component 7 includes an input connector 71 and an output connector 72. The input connector 71 and the output connector 72 are respectively disposed on both sides of the bottom of the stirring drum 61. A spiral tube 73 is fixedly installed between one end of the input connector 71 and the output connector 72. The other end of the input connector 71 and the output connector 72 is electrically connected to a heating device. The spiral tube 73 is located outside the stirring paddle 68 and the two do not intersect. The top end of the cylinder 66 is rotatably installed inside the output end of the bent tube 74 through a sealed bearing. Multiple sets of through air outlets 75 are opened on the arc-shaped sidewall of the stirring rod 67. The cylinder 66, the stirring rod 67 and the bent tube 74 are connected internally, so that the pre-stirring effect is better through the disturbance of airflow. In addition, the input end of the bent tube 74 is connected to the output end of the inert gas supply device, and the output end of the exhaust port 64 is connected to the input end of the waste gas recovery device.

[0029] In one embodiment of the present invention, a flow-dispersing component 8 is provided inside the vessel body 31. The flow-dispersing component 8 includes a conical cover 81, which is conical in shape. Six sets of equally spaced circularly arranged arc-shaped strips 82 are fixedly installed on the arc-shaped outer wall at the top of the conical cover 81. The conical cover 81 is located between the through groove 610 and the fastener. An installation block 83 is fixedly installed on the arc-shaped inner wall of the vessel body 31. A vertical plate 84 is fixedly installed on the installation block 83. Multiple sets of installation blocks 83 and vertical plates 84 are provided and are arranged in an equally spaced circular array. Multiple sets of transverse grooves 85 are opened on a single vertical plate 84. The mixing paddle 58 does not intersect with the vertical plate 84 to avoid motion interference.

[0030] One-way solenoid valves are installed on the pipelines connecting the feed inlet 33, discharge outlet 34, air inlet 42, air outlet 43, feed port 63 and exhaust port 64, as well as on the discharge pipe 65 and bend 74, to facilitate the control of the conveying of the medium inside the corresponding pipeline and avoid backflow.

[0031] Working principle: The frame 1 and support frame 2 provide stable support for the entire equipment. Relying on the vessel body 31 as the core reaction chamber, during operation, the equipment control system is first activated, opening the one-way solenoid valves in each pipeline. Simultaneously, the heating equipment, inert gas supply equipment, and hot gas supply equipment are activated to prepare for the reaction. Phenol and KOH raw materials are fed into the stirring drum 61 through the feeding port 63 at the top of the cylinder cover 62. The asynchronous motor 51 is then activated, driving the rotating shaft 52 to rotate. The rotating shaft 52 drives the drive gear 53 to rotate synchronously. 3. The driven gear 55 is engaged to complete the transmission operation. During the operation of the driven gear 55, the auxiliary gear 69 is driven to accelerate. Since the cross-sectional area of ​​the auxiliary gear 69 is smaller than that of the driven gear 55, the speed is accelerated. The auxiliary gear 69 drives the cylinder 66 to rotate. The cylinder 66 drives the bottom stirring rod 67 and stirring paddle 68 to rotate synchronously. The phenol and KOH raw materials put into the stirring cylinder 61 are sheared and stirred to achieve a full neutralization reaction between the two. The stratification problem caused by the difference in density and polarity of the two raw materials is eliminated in advance, and a uniform potassium phenol dilute solution is formed.

[0032] During the raw material premixing process, auxiliary component 7 works synchronously. Input connector 71 and output connector 72 are connected to heating equipment to heat the spiral tube 73 between them. The premixing reaction temperature inside the stirring drum 61 is regulated by heat conduction to ensure the stable progress of the potassium phenol neutralization reaction. At the same time, the inert gas equipment delivers inert gas into the cylinder 66 and stirring rod 67 through the bent pipe 74. The gas is eventually evenly dispersed from multiple sets of vent holes 75 on the side wall of the stirring rod 67. The dispersed inert gas forms airflow turbulence in the stirring gap of the stirring paddle 68. With the help of gas phase disturbance, the agglomeration of raw materials is broken, further enhancing the premixing and homogenization effect of materials. At the same time, an inert atmosphere environment is created inside the stirring drum 61 to effectively inhibit the oxidation reaction of phenol and reduce the generation of colored impurities. The reaction waste gas generated during the premixing process is discharged to the outside through the exhaust port 64 on the cylinder cover 62 and transported to the waste gas recovery equipment to complete the waste gas purification treatment.

[0033] The potassium phenolate solution, after being premixed and homogenized in the mixing drum 61, is conveyed through the discharge pipe 65 at the bottom of the mixing drum 61 and continuously fed into the reactor body 31 through the through groove 610 opened in the side wall of the bearing seat 56, completing the corresponding raw material premixing and feeding operation. After the raw material enters the reactor body 31, the equipment enters the core reaction stage. The jacket 41 continuously introduces high-temperature hot air through the air inlet 42 to heat up the material inside the reactor body 31. After heat exchange, the hot air is discharged and recovered through the air outlet 43. With the help of temperature sensors and control equipment on the pipeline, the reaction temperature inside the reactor is precisely regulated, providing a stable temperature control environment for the heating, dehydration, and carboxylation reaction of the potassium phenolate solution.

[0034] Meanwhile, the driven gear 55 drives the mixing shaft 57 to rotate synchronously through the rotating rod 54. The mixing shaft 57 drives the two sets of vertically arranged mixing paddles 58 and the bottom V-shaped bottom paddle 59 to operate synchronously. The mixing paddles 58 mix the materials in the upper part of the vessel 31 in all directions. The bottom paddle 59 is adapted to the arc-shaped structure at the bottom of the vessel 31 to continuously stir the materials at the bottom of the vessel, eliminating the problems of material retention and sedimentation at the bottom of the vessel, and realizing the mixing and stirring of materials in the vessel without dead corners. Other raw materials required for the reaction in the vessel 31 can be continuously supplied through the feed port 33 on the vessel cover 32. After the reaction is completed, the finished product is finally discharged from the discharge port 34 at the bottom of the vessel 31, completing the finished product collection operation. The observation window 35 on the vessel cover 32 can observe the reaction and mixing status of the materials inside the vessel 31 in real time.

[0035] During the material mixing and reaction process inside the reactor body 31, the flow disturbance component 8 simultaneously plays an optimization role. Multiple sets of mounting blocks 83 are circumferentially arrayed and fixed to the inner wall of the reactor body 31 to provide fixed support for the vertical plate 84. During the material flow, it passes through multiple sets of transverse grooves 85 on the vertical plate 84 to complete the diversion, breaking the regular material flow field and improving the basic mixing effect. At the same time, the conical cover 81 below the through groove 610 rotates synchronously with the mixing shaft 57 to guide and disperse the premixed potassium phenolate liquid entering the reactor body 31, avoiding material accumulation. Multiple sets of arc-shaped strips 82 fixed on the outside of the conical cover 81 further disturb the surrounding materials, transforming the single circumferential flow field inside the reactor into a three-dimensional turbulent flow field, greatly improving the contact reaction efficiency between CO2 and potassium phenolate solid material, effectively inhibiting the formation of salicylic acid byproducts, and significantly improving the purity and reaction conversion rate of p-hydroxybenzoic acid product. At the same time, the conical cover 81 can shield and protect the fasteners below, preventing material erosion and wear of the fasteners, ensuring long-term stable operation of the equipment, and ultimately achieving efficient and high-purity preparation of p-hydroxybenzoic acid.

[0036] All electrical components appearing in this application are electrically connected to the controller and 220V AC mains power. The controller is a conventional and known device that can control the asynchronous motor 51, feeding equipment, mixture collection equipment, hot gas supply equipment, hot gas recovery equipment, inert gas supply equipment, waste gas recovery equipment, heating equipment, and one-way solenoid valve. The signal interaction of each component adopts the PLC control protocol commonly used in industrial equipment, which is common knowledge to those skilled in the art and can be implemented without additional detailed description. The control logic and signal interaction method are existing technologies and will not be described in detail. All standard parts used in this application can be purchased from the market. The specific connection methods of each part are all connected using conventional methods such as riveting and welding that are mature in the prior art. The standard parts all adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art.

[0037] It should be noted that the above electrical components are all existing technology products. They are selected, installed and debugged by those skilled in the art according to the needs of use to ensure that all electrical appliances can work normally. The components are all general standard parts or parts known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods. No specific restrictions are made here.

[0038] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism, comprising a frame (1), a support frame (2) fixedly mounted on the frame (1), a vessel body (31) fixedly mounted on the support frame (2), a vessel cover (32) fixedly mounted on the top of the vessel body (31), a plurality of feed inlets (33) provided on the vessel cover (32), a discharge outlet (34) provided at the center of the bottom end of the vessel body (31), and a jacket (41) spirally fitted to the outside of the vessel body (31), characterized in that: A mixing component (5) is provided on the vessel body (31), and the mixing component (5) includes an asynchronous motor (51); The asynchronous motor (51) is fixedly installed on the lower surface of the top of the frame (1). Inside the top of the frame (1), a rotating shaft (52) and a rotating rod (54) are rotatably installed via bearing components. The output end of the asynchronous motor (51) is fixedly connected to the bottom end of the rotating shaft (52). A driving gear (53) is fixedly installed on the outside of the rotating shaft (52). A driven gear (55) is fixedly installed on the outside of the rotating rod (54). The driving gear (53) meshes with the driven gear (55). A bearing seat (56) is fixedly installed at the center of the top of the lid (32). The rotating rod (54) is rotatably installed on the bearing seat (56). A mixing shaft (57) is fixedly installed at the bottom of the rotating rod (54) via fasteners. Two sets of vertically aligned mixing paddles (58) are fixedly installed on the outside of the mixing shaft (57). A V-shaped bottom paddle (59) is fixedly installed at the bottom of the mixing shaft (57).

2. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 1, characterized in that: An observation window (35) is also provided on the lid (32).

3. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 1, characterized in that: The multiple sets of feed inlets (33) are respectively connected to the output end of the corresponding feeding equipment, and the discharge outlet (34) is connected to the input end of the mixture collection equipment.

4. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 1, characterized in that: The jacket (41) has an air inlet (42) at its input end, which is used for pipeline connection to the output end of the hot air supply equipment. The jacket (41) also has an air outlet (43) at its output end, which is used for pipeline connection to the input end of the hot air recovery equipment.

5. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 1, characterized in that: A stirring assembly (6) is provided on the frame (1). The stirring assembly (6) includes a stirring drum (61). The stirring drum (61) is fixedly installed inside the top side wall of the frame (1). A drum cover (62) is fixedly installed on the top of the stirring drum (61). A feeding port (63) and an exhaust port (64) are provided on the drum cover (62). The bottom output end of the stirring drum (61) is fixedly connected to the top of the discharge pipe (65). The bottom end of the discharge pipe (65) is fixedly installed inside the side wall of the bearing seat (56). A through groove (610) is opened inside the side wall of the bearing seat (56). The discharge pipe (65) is connected to the inside of the through groove (610).

6. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 5, characterized in that: A cylinder (66) is rotatably mounted inside the top of the frame (1) via a bearing. A stirring rod (67) is fixedly mounted at the bottom of the cylinder (66). Multiple stirring paddles (68) are fixedly mounted on the outside of the stirring rod (67). The stirring paddles (68) are T-shaped. An auxiliary gear (69) is fixedly mounted on the outside of the top of the cylinder (66). The auxiliary gear (69) meshes with the driven gear (55). The area of ​​the circular cross-section of the auxiliary gear (69) is smaller than that of the driven gear (55).

7. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 6, characterized in that: An auxiliary component (7) is provided on the stirring drum (61). The auxiliary component (7) includes an input connector (71) and an output connector (72). The input connector (71) and the output connector (72) are respectively located on both sides of the bottom of the stirring drum (61). A spiral tube (73) is fixedly installed between one end of the input connector (71) and the output connector (72). The other end of the input connector (71) and the output connector (72) is electrically connected to a heating device. The spiral tube (73) is located outside the stirring paddle (68) and the two do not intersect. The top of the cylinder (66) is rotatably installed inside the output end of the bent tube (74) through a sealed bearing. Multiple sets of through air outlets (75) are opened on the arc-shaped sidewall of the stirring rod (67). The cylinder (66), the stirring rod (67) and the bent tube (74) are connected internally.

8. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 7, characterized in that: The input end of the bend (74) is connected to the output end of the inert gas supply device, and the output end of the exhaust port (64) is connected to the input end of the waste gas recovery device.

9. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to claim 5, characterized in that: The vessel body (31) is provided with a flow-dispersing component (8), which includes a conical cover (81). The conical cover (81) is conical. The top arc-shaped outer wall of the conical cover (81) is fixedly installed with multiple sets of equally spaced circularly arranged arc strips (82). The conical cover (81) is located between the through groove (610) and the fastener. The arc-shaped inner wall of the vessel body (31) is fixedly installed with an installation block (83). The installation block (83) is fixedly installed with a vertical plate (84). The installation block (83) and the vertical plate (84) are provided in multiple sets and are equally spaced circularly arranged. Multiple sets of horizontal grooves (85) are opened on a single vertical plate (84). The mixing paddle (58) does not intersect with the vertical plate (84).

10. The reaction vessel for preparing p-hydroxybenzoic acid with a mixing mechanism according to any one of claims 1-9, characterized in that: One-way solenoid valves are provided on the pipelines connecting the feed inlet (33), discharge outlet (34), air inlet (42), air outlet (43), feed port (63) and exhaust port (64), as well as on the discharge pipe (65) and bend (74).

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