Reaction system of methyl p-tert-butylbenzoate

Abstract

The invention relates to the technical field of reaction devices, in particular to a methyl p-tert-butylbenzoate reaction system which comprises a reaction kettle, a feeding box, a movable cylinder, an opening and closing assembly and a detection assembly, a rotating rod is rotationally connected to the reaction kettle, stirring blades are fixed to the outer wall of the rotating rod, a liquid storage cavity is formed in the top of the feeding box, and the liquid storage cavity is communicated with the movable cylinder. A mounting cavity is formed in the bottom of the feeding box, the feeding box is fixed on the side wall of the reaction kettle, a feeding pipe is fixed on the inner wall of the mounting cavity, a plurality of branch pipes are fixed on the side wall of the feeding pipe, regulating valves are fixed in the branch pipes, and the top of the feeding pipe is fixedly communicated with the liquid storage cavity. The movable cylinders are arranged at different heights of the inner wall of the reaction kettle, so that concentrated sulfuric acid can be discharged into the reaction kettle at different heights, the concentrated sulfuric acid is in direct contact with reaction solutions at different heights, high-top and low-bottom catalyst concentration distribution is avoided, the consistency of the catalyst concentration is ensured, and the reaction rate is further promoted.

Description

Technical Field

[0001] This invention relates to the field of reaction apparatus, and more particularly to a reaction system for methyl p-tert-butylbenzoate. Background Technology

[0002] The main production method of methyl p-tert-butylbenzoate involves the esterification reaction of p-tert-butylbenzoic acid and methanol under the catalysis of an acid catalyst. The existing traditional industrial synthesis method of methyl p-tert-butylbenzoate uses a batch reactor. First, p-tert-butylbenzoic acid and methanol are added at once to carry out the esterification reaction. During the reaction, concentrated sulfuric acid is often used as a catalyst. However, because it releases heat violently when dissolved in the reaction solution, if added too quickly, it can easily cause the solution to boil over and cause a safety accident. Therefore, the industrial method often uses a dropwise addition to control the reaction rate. However, during the dropwise addition, the newly injected concentrated sulfuric acid will form a local high-concentration area in the upper part of the reactor. Due to the limited mixing efficiency, a catalyst concentration gradient with a high concentration at the top and a low concentration at the bottom is likely to appear in the reactor. That is, the upper part reacts violently due to catalyst enrichment, while the lower part reacts slowly due to concentration lag. This uneven concentration distribution will significantly affect the consistency of the reaction.

[0003] In the prior art, in order to improve the problem of uneven catalyst concentration, an improved solution has emerged which involves opening discharge holes on the outer wall of the stirring blade or stirring rod. This design connects the concentrated sulfuric acid delivery pipeline with the internal channel of the stirring shaft, allowing the concentrated sulfuric acid to be directly injected into the high-shear zone in the middle of the reaction solution through the discharge holes on the side wall of the stirring rod. This is the strong turbulent mixing zone formed when the stirring blade rotates. This method utilizes the strong dispersion capability of the high-shear environment, which theoretically can shorten the mixing time between the concentrated sulfuric acid and the reaction solution and avoid excessively high local concentrations in the upper part. However, the stirring blades or rods will come into direct contact with highly corrosive concentrated sulfuric acid. The strong oxidizing and dehydrating properties of concentrated sulfuric acid will damage the passivation film on the metal surface. Especially in stress concentration areas such as the edges of the stirring blades, the synergistic effect of mechanical erosion and chemical corrosion will exacerbate local corrosion phenomena such as pitting corrosion and crevice corrosion. Frequent equipment maintenance not only increases downtime costs, but the metal ions generated by corrosion may also contaminate the reaction system, affect the purity of the product, and even cause safety hazards such as the breakage of the stirring shaft due to the decrease in component strength. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as uneven catalyst concentration distribution and corrosion of the stirring blades when discharging concentrated sulfuric acid, by proposing a reaction system for methyl p-tert-butylbenzoate.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a reaction system for methyl tert-butylbenzoate, comprising a reaction vessel, a rotating rod rotatably connected to the reaction vessel, and stirring blades fixed on the outer wall of the rotating rod, characterized in that multiple sliding holes are distributed vertically on the side wall of the reaction vessel, the reaction system further comprising a feeding box, a movable cylinder, an opening and closing assembly, and a detection assembly, the feeding box being fixed to the side wall of the reaction vessel, a liquid storage chamber being provided at the top of the feeding box, an installation cavity being provided at the bottom of the feeding box, a feeding pipe being fixed on the inner wall of the installation cavity, multiple branch pipes being fixed on the side wall of the feeding pipe, a regulating valve being fixed inside the branch pipe, the top of the feeding pipe being fixedly connected to the liquid storage chamber, and the movable cylinder being slidably connected. Inside the sliding hole, a push rod is inserted into the interior of the movable cylinder. A first electric actuator is fixed between the push rod and the outer wall of the reactor. A storage space exists between the push rod and the inner wall of the movable cylinder. A slot communicating with the storage space is opened inside the push rod. The branch pipe is inserted into the slot. A second electric actuator is fixed inside the push rod. The movable end of the second electric actuator is fixed to the inner wall of the movable cylinder. The discharge hole is opened on the outer wall of the movable cylinder. The opening and closing assembly is located inside the discharge hole. The detection assembly is used to detect the position of the stirring blade. When the stirring blade is detected to be close to the discharge hole, the discharge hole is closed. When the stirring blade is detected to be away from the discharge hole, the discharge hole is opened.

[0006] Specifically, to address the problem of uneven catalyst concentration distribution in existing technologies, the present invention operates as follows: Initially, the second electric actuator is extended, maximizing the storage space and closing the discharge port. Concentrated sulfuric acid is introduced into the storage space through the feed pipe and branch pipe. Then, the first electric actuator drives the push rod to move into the reactor. Under the connection of the second electric actuator, the push rod and the movable cylinder move synchronously into the reactor, adjusting the position of the discharge port. Once the discharge port reaches the designated position, the second electric actuator is retracted, pulling the movable cylinder closer to the push rod, reducing the storage space. Under hydraulic pressure, the opening and closing assembly is activated, opening the discharge port and discharging the concentrated sulfuric acid from the storage space into the reactor. By placing movable cylinders at different heights on the inner wall of the reactor, concentrated sulfuric acid can be discharged into the reactor at different heights, allowing the concentrated sulfuric acid to directly contact the reaction solution at different heights. This avoids a catalyst concentration distribution that is higher at the top and lower at the bottom, ensuring the consistency of the catalyst concentration and thus promoting the reaction rate. Furthermore, by controlling the slow retraction of the second electric actuator, the concentrated sulfuric acid can be discharged slowly, avoiding the problem of a rapid increase in temperature inside the reactor caused by excessive discharge of concentrated sulfuric acid. During the discharge process, the position of the discharge port is constantly moving, which also helps to avoid the problem of boiling over caused by heat concentrating in a single location. Furthermore, to avoid corrosion of the stirring blades when discharging concentrated sulfuric acid, this invention incorporates a detection component. When the stirring blades are detected approaching the discharge port, the discharge port is closed; when the stirring blades are detected moving away from the discharge port, the discharge port is opened. This allows the concentrated sulfuric acid to first contact the methanol solution, rapidly diluting it through localized mixing, thus reducing the overall concentration of the solution. This reduces the direct corrosion of the stirring blades by the high-concentration sulfuric acid. Moreover, discharging sulfuric acid into the gap between the stirring blades and the discharge position prevents the stirring blades from directly scouring the high-concentration sulfuric acid area, shortening the contact time between the stirring blades and the highly corrosive medium, which also helps to slow down the corrosion rate.

[0007] Preferably, the detection assembly includes multiple sets of trigger rods and detection boxes, each set of trigger rods having two rods, the detection box being fixed on the top surface of the reactor, the inside of the detection box having a sliding groove, a pressure sensor being fixed on the inner wall of the sliding groove, a detection rod being fixed inside the sliding groove, and a first spring being fixed between the detection rod and the pressure sensor.

[0008] Specifically, when the stirring blades approach the discharge port, they may come into direct contact with concentrated sulfuric acid, causing damage. To address this issue, this invention installs a detection rod directly above the discharge port, and two trigger rods are positioned directly above each blade, corresponding to the edge of the blade. During blade rotation, one of the trigger rods will first contact the detection rod. Both the trigger rod and the detection rod have rounded end faces. When the trigger rod contacts the detection rod, it pushes the detection rod into the chute, thereby compressing the first spring. The first spring then pushes the pressure sensor. When the pressure sensor detects an increase in pressure, it confirms contact with the trigger rod, and the stirring blade is about to move closer to the discharge port. The system controls the second electric actuator to stop retracting. After the opening and closing assembly loses its hydraulic pressure, it can close the discharge port, thus preventing concentrated sulfuric acid from being discharged. When another trigger rod contacts the detection rod, the pressure sensor detects an increase in pressure for the second time, determining that the stirring blades are moving away from the discharge port. This controls the second electric actuator to continue retracting, discharging concentrated sulfuric acid. This allows the concentrated sulfuric acid to first contact the methanol solution, rapidly diluting it through local mixing, reducing the overall concentration of the solution. This reduces the direct corrosion of the stirring blades by high-concentration sulfuric acid. Furthermore, discharging sulfuric acid into the gap between the stirring blades and the discharge position avoids the stirring blades directly scouring the high-concentration sulfuric acid area, shortening the contact time between the stirring blades and the highly corrosive medium, which also helps to slow down the corrosion rate.

[0009] Preferably, the opening and closing assembly includes a mounting block, which is fixed inside the feeding hole. The mounting block has a through groove and an expansion groove inside, which communicate with each other. The through groove is located above the expansion groove. A sealing plug is slidably connected inside the through groove. A support plate is fixed on the inner wall of the expansion groove. A second spring is fixed between the support plate and the expansion groove.

[0010] Preferably, a guide block is provided inside the feeding hole, a guide hole is provided in the middle of the guide block, and a threaded groove is provided on the inner wall of the guide hole.

[0011] Preferably, a storage groove is provided on one side of the feeding hole, a storage plug is slidably connected inside the storage groove, a third spring is fixed between the storage plug and the storage groove, and a damping component is provided on the outer wall of the storage plug to slow down the retraction speed of the storage plug.

[0012] Preferably, the damping assembly includes a mounting groove formed on the inner wall of the accumulator. A vertical groove is formed at the top of the mounting groove, and a pressing block is vertically slidably connected inside the vertical groove. A friction surface is provided on the side of the pressing block near the accumulator groove. A pushing block is slidably connected inside the mounting groove, and an inclined surface is provided on the side of the pushing block near the pressing block. A fourth spring is fixed between the pushing block and the inner wall of the mounting groove. A one-way limiting assembly is provided above the pressing block. When the accumulator moves away from the third spring, the one-way limiting assembly is used to limit the pressing block from rising.

[0013] Preferably, the unidirectional limiting component includes a sliding groove, which is opened at the end of the accumulator away from the third spring. A limiting block is slidably connected inside the sliding groove, and the top surface of the limiting block is in frictional contact with the inner wall of the mounting groove.

[0014] Preferably, an extension rod is fixed to the bottom of the sealing plug, and a sealing block is fixed to the bottom of the extension rod after passing through the support plate. The sealing block is positioned directly above the guide hole. A guide groove is formed on the bottom surface of the sealing block, and a slot is formed on the side wall of the guide block. A support ring is fitted inside the slot, and the support ring is fixed to the inner wall of the discharge hole. A fifth spring is fixed between the support ring and the inner wall of the slot. A positioning component is provided on one side of the slot. The positioning component is used to position the guide block. When the accumulator moves to the end of the accumulator groove, the accumulator triggers the positioning component to cancel the positioning of the guide block.

[0015] Preferably, the positioning component includes a positioning rod, which is slidably inserted into the interior of the movable cylinder. One end of the positioning rod extends into the slot, and the other end of the positioning rod is fixed with an L-shaped rod. The L-shaped rod is inserted into the mounting groove, and a bracket is fixed inside the mounting groove. A sixth spring is fixed between the bracket and the L-shaped rod.

[0016] Preferably, a filling rod is fixed to the bottom of the sealing block, and the filling rod is inserted inside the guide groove.

[0017] Compared with the prior art, the present invention has the following beneficial effects: By setting movable cylinders at different heights on the inner wall of the reactor, concentrated sulfuric acid can be discharged into the reactor at different heights, allowing the concentrated sulfuric acid to directly contact the reaction solution at different heights, avoiding a catalyst concentration distribution that is high at the top and low at the bottom, ensuring the consistency of the catalyst concentration, and thus promoting the reaction rate; by setting a detection component, when the stirring blade is detected to be close to the discharge hole, the discharge hole is closed, and when the stirring blade is detected to be far away from the discharge hole, the discharge hole is opened, allowing the concentrated sulfuric acid to first contact the methanol solution, and rapidly dilute it through local mixing, reducing the overall concentration of the solution, which can reduce the direct corrosion of the stirring blade by high concentration sulfuric acid. Furthermore, the sulfuric acid is discharged in the gap between the stirring blade and the discharge position, avoiding the stirring blade directly scouring the high concentration sulfuric acid area, shortening the contact time between the stirring blade and the highly corrosive medium, which also helps to slow down the corrosion rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the reaction system in one embodiment of the present invention; Figure 2 This is a cross-sectional perspective view of the reaction system in one embodiment of the present invention; Figure 3 for Figure 2 A magnified view of a section at point A in the middle; Figure 4 for Figure 2 A magnified view of a section at point B in the middle; Figure 5 for Figure 4 A magnified view of a section at point C; Figure 6 for Figure 5 A magnified view of a section at point D; Figure 7 This is a schematic diagram of the cross-sectional structure of the accumulator in one embodiment of the present invention; Figure 8 This is a schematic diagram of the assembly structure of the extension rod, the sealing block, and the guide channel in one embodiment of the present invention. In the diagram: 1. Reactor; 2. Rotating rod; 3. Stirring blade; 4. Feeding box; 5. Storage chamber; 6. Mounting chamber; 7. Feeding pipe; 8. Branch pipe; 9. Sliding hole; 10. Movable cylinder; 11. Pushing rod; 12. First electric actuator; 13. Storage space; 14. Slot; 15. Second electric actuator; 16. Discharge hole; 17. Trigger rod; 18. Detection box; 19. Slide groove; 20. Pressure sensor; 21. Detection rod; 22. First spring; 23. Mounting block; 24. Through groove; 25. Expansion groove; 26. Sealing plug; 7. Support plate; 28. Second spring; 29. ​​Guide block; 30. Guide hole; 31. Threaded groove; 32. Energy storage groove; 33. Energy storage plug; 34. Third spring; 35. Mounting groove; 36. Vertical groove; 37. Extrusion block; 38. Pushing block; 39. Fourth spring; 40. Sliding groove; 41. Limiting block; 42. Extension rod; 43. Sealing block; 44. Guide groove; 45. Slot; 46. Support ring; 47. Fifth spring; 48. Positioning rod; 49. L-shaped rod; 50. Bracket; 51. Sixth spring; 52. Filling rod. Detailed Implementation

[0019] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0020] like Figures 1 to 8 The reaction system for methyl tert-butylbenzoate shown includes a reaction vessel 1, a rotating rod 2 rotatably connected to the reaction vessel 1, a stirring blade 3 fixed to the outer wall of the rotating rod 2, and a motor fixed to the top of the rotating rod 2, which drives the stirring blade 3 to rotate. Multiple sliding holes 9 are provided on the side wall of the reaction vessel 1, distributed along the vertical direction of the reaction vessel 1. The system also includes: The feeding box 4 has a liquid storage chamber 5 at its top and an installation chamber 6 at its bottom. The feeding box 4 is fixed to the side wall of the reactor 1. A feeding pipe 7 is fixed to the inner wall of the installation chamber 6. Multiple branch pipes 8 are fixed to the side wall of the feeding pipe 7. A regulating valve is fixed inside the branch pipe 8. The top of the feeding pipe 7 is fixedly connected to the liquid storage chamber 5. The movable cylinder 10 is slidably connected in the sliding hole 9. A push rod 11 is inserted inside the movable cylinder 10. A first electric push rod 12 is fixed between the push rod 11 and the outer wall of the reactor 1. A storage space 13 is provided between the push rod 11 and the inner wall of the movable cylinder 10. A slot 14 is opened inside the push rod 11 and communicates with the storage space 13. A branch pipe 8 is inserted inside the slot 14. A second electric push rod 15 is fixed inside the push rod 11. The movable end of the second electric push rod 15 is fixed to the inner wall of the movable cylinder 10. A discharge hole 16 is opened on the outer wall of the movable cylinder 10. An opening and closing component is located inside the discharge hole 16; The detection component is used to detect the position of the stirring blade. When the stirring blade 3 is detected to be close to the discharge hole 16, the discharge hole 16 is closed. When the stirring blade 3 is detected to be far away from the discharge hole 16, the discharge hole 16 is opened.

[0021] Specifically, to address the problem of uneven catalyst concentration distribution in existing technologies, the present invention operates as follows: Initially, the second electric actuator 15 is in an extended state, at which point the storage space 13 is at its maximum size, and the discharge port 16 is closed. Concentrated sulfuric acid is introduced into the storage space 13 through the feed pipe 7 and branch pipe 8. Then, the first electric actuator 12 drives the push rod 11 to move into the reactor 1. Under the connecting action of the second electric actuator 15, the push rod 11 and the movable cylinder 10 move synchronously into the reactor 1, adjusting the position of the discharge port 16. 6. After reaching the designated position, control the second electric actuator 15 to retract, pull the movable cylinder 10 to move towards the side closer to the top actuator 11, reduce the storage space 13, and open the opening and closing assembly under hydraulic action, so that the discharge hole 16 opens, thereby discharging the concentrated sulfuric acid in the storage space 13 into the reactor 1. By setting the movable cylinder 10 at different heights on the inner wall of the reactor 1, concentrated sulfuric acid can be discharged into the reactor 1 at different heights, so that the concentrated sulfuric acid can directly contact the reaction solution at different heights, avoid the catalyst concentration distribution of high at the top and low at the bottom, ensure the consistency of catalyst concentration, and thus promote the reaction rate. Furthermore, by controlling the slow retraction of the second electric actuator 15, the concentrated sulfuric acid can be discharged slowly, avoiding the problem of the concentrated sulfuric acid being discharged too quickly, which would cause the temperature inside the reactor 1 to rise sharply. During the discharge process, the position of the discharge hole 16 is constantly moving, which also helps to avoid the problem of boiling over caused by heat concentrating in a single location. Furthermore, to avoid corrosion of the stirring blades when discharging concentrated sulfuric acid, this invention incorporates a detection component. When the stirring blade 3 is detected approaching the discharge hole 16, the discharge hole 16 is closed; when the stirring blade 3 is detected moving away from the discharge hole 16, the discharge hole 16 is opened. This allows the concentrated sulfuric acid to first contact the methanol solution, rapidly diluting it through local mixing, thus reducing the overall concentration of the solution. This reduces the direct corrosion of the stirring blades by high-concentration sulfuric acid. Moreover, discharging sulfuric acid into the gap between the stirring blade 3 and the discharge position prevents the stirring blade 3 from directly scouring the high-concentration sulfuric acid area, shortening the contact time between the stirring blade 3 and the highly corrosive medium, which also helps to slow down the corrosion rate.

[0022] As a further embodiment of the present invention, the detection assembly includes multiple sets of trigger rods 17 and detection boxes 18. Each set of trigger rods 17 has two rods. The detection box 18 is fixed on the top surface of the reactor 1. A sliding groove 19 is opened inside the detection box 18. A pressure sensor 20 is fixed on the inner wall of the sliding groove 19. A detection rod 21 is fixed inside the sliding groove 19. A first spring 22 is fixed between the detection rod 21 and the pressure sensor 20.

[0023] Specifically, when the stirring blade 3 approaches the discharge port, it may come into direct contact with concentrated sulfuric acid, causing damage. To solve this problem, the present invention provides a detection rod 21 directly above the discharge port, and two trigger rods 17 are positioned directly above each blade, corresponding to the edge of the blade. During blade rotation, one of the trigger rods 17 will first contact the detection rod 21. Both the trigger rod 17 and the detection rod 21 have rounded end faces. When the trigger rod 17 contacts the detection rod 21, it pushes the detection rod 21 into the slide groove 19, thereby compressing the first spring 22. The first spring 22 then pushes the pressure sensor 20. When the pressure sensor 20 detects an increase in pressure, it confirms contact with the trigger rod 17, and the stirring blade 3 is about to move. The actuator moves to a position close to the discharge port, thereby controlling the second electric actuator 15 to stop retracting. After the opening and closing assembly loses its hydraulic action, it can close the discharge port, thereby preventing concentrated sulfuric acid from being discharged. When another trigger rod 17 contacts the detection rod 21, the pressure sensor 20 detects an increase in pressure value for the second time, determining that the stirring blade 3 is away from the discharge port, thereby controlling the second electric actuator 15 to continue retracting and discharging concentrated sulfuric acid. This allows the concentrated sulfuric acid to first contact the methanol solution, rapidly diluting it through local mixing, reducing the overall concentration of the solution. This can reduce the direct corrosion of the stirring blade 3 by high-concentration sulfuric acid. Furthermore, discharging sulfuric acid in the gap between the stirring blade 3 and the discharge position avoids the stirring blade 3 directly scouring the high-concentration sulfuric acid area, shortening the contact time between the stirring blade 3 and the highly corrosive medium, which also helps to slow down the corrosion rate.

[0024] As a further embodiment of the present invention, the opening and closing component includes a mounting block 23, which is fixed inside the feeding hole 16. The mounting block 23 has a through groove 24 and an expansion groove 25 inside. The through groove 24 communicates with the expansion groove 25 and is located above the expansion groove 25. A sealing plug 26 is slidably connected inside the through groove 24. A support plate 27 is fixed on the inner wall of the expansion groove 25, and a second spring 28 is fixed between the support plate 27 and the expansion groove 25. Specifically, when hydraulic pressure is generated in the storage space 13, the sealing plug 26 is pushed away from the through groove 24 and into the expansion groove 25 under the action of hydraulic pressure. Since the outer diameter of the sealing plug 26 is smaller than the inner diameter of the expansion groove 25, a gap is generated between the sealing plug 26 and the expansion groove 25. Concentrated sulfuric acid flows into the expansion groove 25 through the gap and flows into the feed hole 16 from the bottom of the expansion groove 25. It then flows out from the bottom of the feed hole 16 and is discharged into the reactor 1. When the hydraulic pressure in the storage space 13 disappears, the sealing plug 26 can re-enter the through groove 24 under the force of the second spring 28 and seal the through groove 24, preventing the concentrated sulfuric acid from falling further and completing the closing function.

[0025] As a further embodiment of the present invention, a guide block 29 is provided inside the feed hole 16, a guide hole 30 is provided in the middle of the guide block 29, and a threaded groove 31 is provided on the inner wall of the guide hole 30.

[0026] Specifically, by creating a threaded groove 31 within the guide hole 30, concentrated sulfuric acid can flow and be discharged along the spiral path of the threaded groove 31. This design effectively breaks the agglomeration state of the liquid during discharge, allowing the concentrated sulfuric acid to contact the reaction liquid in a spiral diffusion manner, extending its mixing path during flow. With the rotational momentum provided by the threaded structure, the concentrated sulfuric acid liquid flow is more quickly integrated into the surrounding reaction liquid after discharge, significantly reducing the formation of local high-concentration areas. This not only improves the uniformity of catalyst dispersion but also reduces the risk of equipment corrosion by avoiding direct impact and continuous scouring of the fluid on the stirring components, thereby ensuring the stability of the reaction process, reducing the generation of by-products, and providing a more reliable technical path for optimizing reaction efficiency and product quality.

[0027] As a further embodiment of the present invention, a power storage groove 32 is provided on one side of the feeding hole 16, a power storage plug 33 is slidably connected inside the power storage groove 32, a third spring 34 is fixed between the power storage plug 33 and the power storage groove 32, and a damping component is provided on the outer wall of the power storage plug 33. The damping component is used to slow down the retraction speed of the power storage plug 33. Specifically, when concentrated sulfuric acid is discharged intermittently, when the discharge operation stops, the residual concentrated sulfuric acid at the bottom of the sealing plug 26 will still remain in contact with the reaction solution. At this time, due to the loss of hydraulic extrusion, the pressure balance inside and outside the discharge hole 16 is broken, and the reaction solution may backflow into the discharge hole 16 due to the pressure difference. In such a narrow space as the discharge hole 16, the residual concentrated sulfuric acid and the backflowed reaction solution will form a local micro-reaction system. The heat released when the two mix is ​​difficult to dissipate effectively due to the space limitation, causing the temperature in this area to rise rapidly. This local overheating may not only aggravate the occurrence of side reactions and generate more impurities that affect the purity of the product, but may also cause thermal stress concentration in the inner wall material of the discharge hole 16 due to heat accumulation. In the long term, the pipe material is prone to aging or local deformation. This invention can solve the above problems. The specific working method is as follows: When concentrated sulfuric acid is discharged through the discharge hole 16, the hydraulic action will push the accumulator 33 to move towards one end of the accumulator tank 32, so that the built-in third spring 34 is stretched and stores elastic potential energy. When the sealing plug 26 closes and stops the acid discharge, the pull force generated by the elastic deformation of the third spring 34 will drive the accumulator 33 to retract to the initial position. This retraction movement can continuously squeeze the concentrated sulfuric acid in the accumulator tank 32 slowly out of the discharge hole 16, ensuring that the discharge hole 16 still maintains a slight positive pressure discharge state during the acid discharge gap, thereby effectively preventing the reaction solution from flowing back into the hole due to the pressure difference.

[0028] To prevent the accumulator plug 33 from retracting too quickly and causing the concentrated sulfuric acid discharge rate to become uncontrollable, the damping component added to the system can evenly and gradually release the spring's pull-back kinetic energy through frictional resistance or fluid damping effect, allowing the accumulator plug 33 to reset at a stable speed. This not only controls the discharge rate of concentrated sulfuric acid within a safe range, but also prevents high-speed liquid flow from directly impacting the stirring blades 3, reducing the risk of equipment corrosion. This structural design, which integrates accumulator compensation, continuous pressure discharge, and flow rate buffering, ensures the unidirectional flow of the discharge hole 16 during intermittent acid discharge through dynamic conversion of mechanical potential energy and damping control, and also achieves a stable and controllable concentrated sulfuric acid discharge process. This fundamentally solves the problems of solution backflow, local overheating, and uneven flow rate that are prone to occur in traditional intermittent acid discharge methods.

[0029] As a further embodiment of the present invention, the damping component includes a mounting groove 35, which is formed on the inner wall of the accumulator 33. A vertical groove 36 is formed at the top of the mounting groove 35. A pressing block 37 is vertically slidably connected inside the vertical groove 36. A friction surface is provided on the side of the pressing block 37 near the accumulator 32. A pushing block 38 is slidably connected inside the mounting groove 35. An inclined surface is provided on the side of the pushing block 38 near the pressing block 37. A fourth spring 39 is fixed between the pushing block 38 and the inner wall of the mounting groove 35. A one-way limiting component is provided above the pressing block 37. When the accumulator 33 moves away from the third spring 34, the one-way limiting component is used to limit the pressing block 37 from rising. The one-way limiting component includes a sliding groove 40, which is located at the end of the accumulator 33 away from the third spring 34. A limiting block 41 is slidably connected inside the sliding groove 40, and the top surface of the limiting block 41 is in frictional contact with the inner wall of the mounting groove 35.

[0030] Specifically, since concentrated sulfuric acid is highly corrosive, ordinary damping rubber is difficult to apply to this device. Furthermore, if the rotation speed of the stirring blade 3 is too fast, the opening time of the discharge hole 16 will be shortened, which may lead to insufficient energy storage time. The present invention improves the damping component as follows: During the energy storage process, the energy storage plug 33 moves away from the third spring 34. At this time, under the action of friction, the limiting block 41 will move into the vertical groove 36 and move above the extrusion block 37 to prevent the extrusion block 37 from rising. This avoids the extrusion block 37 from contacting the inner wall of the mounting groove 35 to generate frictional damping, so that the energy storage plug 33 can quickly complete the displacement with less resistance, ensuring that sufficient elastic potential energy is stored within the limited opening time of the discharge hole 16. When the concentrated sulfuric acid injection stops and the accumulator 33 moves in the reverse direction under the pull of the third spring 34, the limiting block 41 will disengage from the upper part of the extrusion block 37 and from the limiting area of ​​the extrusion block 37 under the action of friction. Under the action of hydraulic pressure, the pushing block 38 moves into the interior of the mounting groove 35 and pushes the extrusion block 37 upward through the inclined surface. The friction surface of the extrusion block 37 contacts the mounting groove 35, generating frictional damping and slowing down the retraction speed of the accumulator 33. This allows the concentrated sulfuric acid to be discharged from the discharge hole 16 at a stable low speed, which avoids backflow of the reaction solution and prevents corrosion caused by the impact of high-speed liquid flow on the stirring blades 3. Without the need to use easily corrosive materials such as rubber, it achieves low-resistance rapid energy storage in the accumulating process and controllable damping slow release in the discharge process, which significantly improves the stability and reliability of the entire reaction system.

[0031] As a further embodiment of the present invention, an extension rod 42 is fixed to the bottom of the sealing plug 26. The bottom of the extension rod 42 passes through the support plate 27 and is fixed to a sealing block 43. The sealing block 43 is positioned directly above the guide hole 30. A guide groove 44 is formed on the bottom surface of the sealing block 43. A slot 45 is formed on the side wall of the guide block 29. A support ring 46 is fitted inside the slot 45. The support ring 46 is fixed to the inner wall of the discharge hole 16. A fifth spring 47 is fixed between the support ring 46 and the inner wall of the slot 45. A positioning component is provided on one side of the slot 45. The positioning component is used to position the guide block 29. When the accumulator 33 moves to the end of the accumulator groove 32, the accumulator 33 triggers the positioning component to cancel the positioning of the guide block 29. The positioning component includes a positioning rod 48, which is slidably inserted into the inside of the movable cylinder 10. One end of the positioning rod 48 extends into the inside of the slot 45, and the other end of the positioning rod 48 is fixed with an L-shaped rod 49. The L-shaped rod 49 is inserted into the inside of the mounting groove 35. A bracket 50 is fixed inside the mounting groove 35, and a sixth spring 51 is fixed between the bracket 50 and the L-shaped rod 49.

[0032] Specifically, during the power storage process, if the discharge hole 16 discharges liquid simultaneously, insufficient back pressure may lead to unstable discharge power, resulting in unstable discharge flow. This invention can solve the above problem. The specific working method is as follows: under hydraulic action, the sealing plug 26 is pushed down. When the discharge hole 16 is opened, the sealing plug 26 will simultaneously drive the extension rod 42 and the sealing block 43 to descend. The sealing block 43 blocks the top of the guide hole 30 of the guide block 29, and only a small amount of liquid enters the guide hole 30 from the guide groove 44. To ensure the solution in the guide hole 30 is always in an outflow state, most of the liquid first enters the accumulator 32. As the liquid inside the accumulator 32 increases, it pushes the accumulator plug 33 towards the side closer to the L-shaped rod 49, and pushes the L-shaped rod 49 away from the side of the accumulator 32. The L-shaped rod 49 drives the positioning rod 48 to move, causing the positioning rod 48 to disengage from the slot 45. At this point, the accumulating force is complete, and the hydraulic action pushes the guide block 29 downward, disengaging it from the blocking block 43, thus allowing most of the liquid to flow out of the guide hole 30. In this implementation, by controlling the timing of filling the accumulator tank 32 with most of the liquid before opening the guide hole 30, a stable pressure environment is ensured in the accumulator tank 32 before the guide hole 30 is opened over a large area. On the one hand, the temporary partial blockage of the guide hole 30 by the sealing block 43 avoids liquid flow impact and flow fluctuation caused by insufficient accumulator in the initial stage. On the other hand, the mechanical interlocking mechanism of the accumulator plug 33 pushing the L-shaped rod 49 to trigger the positioning rod 48 to disengage from the slot 45 ensures that the guide hole 30 will only be fully opened after the accumulator tank 32 is completely filled and a constant back pressure is established, thereby controlling the fluctuation of the discharge flow rate to an extremely low level. This scheme cleverly utilizes the coupling effect of mechanical limiting and fluid pressure to achieve a smooth transition in the concentrated sulfuric acid discharge process without the need for complex sensors. From the structural design level, it eliminates the hidden danger of flow instability caused by insufficient filling in traditional accumulator devices, provides a continuous and uniform catalyst supply for the reaction system, and effectively improves the controllability of the entire process and the consistency of product quality.

[0033] As a further embodiment of the present invention, a filling rod 52 is fixed to the bottom of the sealing block 43, and the filling rod 52 is inserted into the guide groove 44.

[0034] Specifically, when the liquid enters the guide hole 30, the filling rod 52 set inside the hole forms an annular flow channel structure with the inner wall of the guide hole 30 through its specific cylindrical profile. This design can effectively restrict the free flow space inside the hole, ensuring that most of the liquid can flow out preferentially through the threaded groove 31, significantly reducing the agglomerated liquid flow that sprays directly from the middle of the channel. This allows concentrated sulfuric acid to contact the reaction liquid in a spiral diffusion form, which not only extends the path of the liquid flow in the mixing area, but also promotes droplet breakage with the centrifugal force provided by the threaded groove 31, further improving the dispersion uniformity of the catalyst in the reactor 1. This structurally solves the problem of central jet agglomeration that is prone to occur in traditional guide holes 30, creating favorable conditions for the stable progress of subsequent reactions.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A reaction system for methyl p-tert-butylbenzoate, characterized in that, The reactor includes a rotating rod rotatably connected to the reactor, and stirring blades are provided on the rotating rod. Multiple sliding holes are distributed vertically on the side wall of the reactor. The reaction system also includes a feeding box, a movable cylinder, an opening and closing assembly, and a detection assembly. The feeding box is located on the side wall of the reactor. A liquid storage chamber is located at the top of the feeding box, and an installation cavity is located at the bottom of the feeding box. A feeding pipe is fixed to the inner wall of the installation cavity, and multiple branch pipes are fixed to the side wall of the feeding pipe. A regulating valve is fixed inside each branch pipe. The top of the feeding pipe is fixedly connected to the liquid storage chamber. The movable cylinder is slidably connected within the sliding hole. A push rod is inserted inside the movable cylinder, and a first electric actuator is fixed between the push rod and the outer wall of the reactor. There is a storage space between the moving cylinder and the inner wall of the moving cylinder. The inside of the push rod is provided with a slot communicating with the storage space. The branch pipe is inserted into the slot. A second electric push rod is fixed inside the push rod. The movable end of the second electric push rod is fixed to the inner wall of the moving cylinder. The discharge hole is opened on the outer wall of the moving cylinder. The opening and closing component is provided in the discharge hole. The detection component is used to detect the position of the stirring blade. When the stirring blade is detected to be close to the discharge hole, the discharge hole is closed. When the stirring blade is detected to be away from the discharge hole, the discharge hole is opened.

2. The reaction system for methyl p-tert-butylbenzoate according to claim 1, characterized in that: The detection assembly includes multiple sets of trigger rods and detection boxes. Each set of trigger rods has two rods. The detection box is fixed on the top surface of the reactor. A sliding groove is opened inside the detection box. A pressure sensor is fixed on the inner wall of the sliding groove. A detection rod is fixed inside the sliding groove. A first spring is fixed between the detection rod and the pressure sensor.

3. The reaction system for methyl p-tert-butylbenzoate according to claim 1, characterized in that: The opening and closing assembly includes a mounting block, which is fixed inside the feeding hole. The mounting block has a through groove and an expansion groove inside. The through groove communicates with the expansion groove and is located above the expansion groove. A sealing plug is slidably connected inside the through groove. A support plate is fixed on the inner wall of the expansion groove, and a second spring is fixed between the support plate and the expansion groove.

4. The reaction system for methyl p-tert-butylbenzoate according to claim 3, characterized in that: The feed hole is provided with a guide block inside, and a guide hole is opened in the middle of the guide block. A threaded groove is opened on the inner wall of the guide hole.

5. The reaction system for methyl p-tert-butylbenzoate according to claim 4, characterized in that: A storage groove is provided on one side of the feeding hole. A storage plug is slidably connected inside the storage groove. A third spring is fixed between the storage plug and the storage groove. A damping component is provided on the outer wall of the storage plug. The damping component is used to slow down the retraction speed of the storage plug.

6. The reaction system for methyl p-tert-butylbenzoate according to claim 5, characterized in that: The damping assembly includes a mounting groove formed on the inner wall of the accumulator. A vertical groove is formed at the top of the mounting groove, and a pressing block is vertically slidably connected inside the vertical groove. A friction surface is provided on the side of the pressing block near the accumulator groove. A pushing block is slidably connected inside the mounting groove, and an inclined surface is provided on the side of the pushing block near the pressing block. A fourth spring is fixed between the pushing block and the inner wall of the mounting groove. A one-way limiting assembly is provided above the pressing block. When the accumulator moves away from the third spring, the one-way limiting assembly is used to limit the pressing block from rising.

7. The reaction system for methyl p-tert-butylbenzoate according to claim 6, characterized in that: The unidirectional limiting component includes a sliding groove, which is formed at the end of the accumulator away from the third spring. A limiting block is slidably connected inside the sliding groove, and the top surface of the limiting block is in frictional contact with the inner wall of the mounting groove.

8. The reaction system for methyl p-tert-butylbenzoate according to claim 5, characterized in that: An extension rod is fixed to the bottom of the sealing plug. The bottom of the extension rod passes through the support plate and is fixed to a sealing block. The sealing block is positioned directly above the guide hole. A guide groove is formed on the bottom surface of the sealing block. A slot is formed on the side wall of the guide block. A support ring is fitted inside the slot. The support ring is fixed to the inner wall of the discharge hole. A fifth spring is fixed between the support ring and the inner wall of the slot. A positioning component is provided on one side of the slot. The positioning component is used to position the guide block. When the accumulator moves to the end of the accumulator groove, the accumulator triggers the positioning component to cancel the positioning of the guide block.

9. The reaction system for methyl p-tert-butylbenzoate according to claim 8, characterized in that: The positioning component includes a positioning rod that is slidably inserted inside the movable cylinder. One end of the positioning rod extends into the slot, and the other end of the positioning rod is fixed with an L-shaped rod. The L-shaped rod is inserted into the mounting groove, and a bracket is fixed inside the mounting groove. A sixth spring is fixed between the bracket and the L-shaped rod.

10. The reaction system for methyl p-tert-butylbenzoate according to claim 8, characterized in that: A filling rod is fixed to the bottom of the sealing block, and the filling rod is inserted inside the guide groove.

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