A pressurizing device for an N-vinylcaprolactam reactor

Abstract

The utility model provides a kind of N-vinyl caprolactam pressure device of reaction kettle, and the first pressure measuring device is provided on the reaction kettle with gas inlet and, the first pressure measuring device includes the buffer tank containing gas raw material, the gas outlet of buffer tank is connected with the gas inlet of reaction kettle by first pipeline, pressure pump, flowmeter, first regulating valve are sequentially provided on first pipeline, pressure pump is located between the gas outlet of buffer tank and flowmeter, pressure pump is provided with instrument gas inlet, instrument gas inlet is connected with instrument gas supply device by second pipeline, solenoid valve is provided on second pipeline, solenoid valve is connected with the first pressure measuring device by signal. The first pressure measuring device monitors the pressure in the reaction kettle in real time, once it is found that the pressure is lower than the threshold value, the first pressure measuring device will send a signal to the solenoid valve, so that it controls the instrument gas to provide power for the pressure pump, the gas in the buffer tank is compressed and pushed into the reaction kettle, the whole process is automatically adjusted, and the hidden trouble caused by human operation error is reduced.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically to a pressurization device for an N-vinylcaprolactam reactor. Background Technology

[0002] N-Vinylcaprolactam (NVCL), a key vinyl monomer, has wide applications in various industries such as pharmaceuticals and chemicals. Among its synthetic routes, the acetylene method has become the mainstream process due to its mild reaction conditions and high conversion rate. However, the existing pressurized equipment for N-vinylcaprolactam synthesis suffers from a series of technical bottlenecks, limiting its efficient application in industrial production.

[0003] First, the precision of pressure control is insufficient. Accurate pressure control within the reactor is crucial in synthetic reactions. Existing equipment often relies on manual adjustment, which not only increases the workload of operators but also makes it difficult to achieve continuous and stable process parameter control, easily leading to fluctuations in reaction conditions and affecting the final product quality and yield. Second, the stability and safety of the equipment need improvement. Unstable internal pressure in the reactor can trigger safety accidents, such as the risk of explosion due to overpressure or reaction stagnation due to underpressure. Furthermore, the lack of effective monitoring and automatic adjustment mechanisms necessitates frequent operator intervention during long-term operation, increasing production costs and reducing work efficiency.

[0004] Moreover, the existing technology for power supply to acetylene pneumatic booster pumps is relatively simple, usually using direct electric drive. This method poses safety hazards in areas handling hazardous chemicals, and has high maintenance costs and is inconvenient to operate.

[0005] In summary, existing pressurized units for N-vinylcaprolactam synthesis have significant shortcomings in terms of pressure control accuracy, equipment stability and safety, intelligent acetylene gas supply, and power supply methods. An innovative solution is urgently needed to overcome these technical obstacles, improve reaction efficiency, reduce production costs, and ensure operational safety. To address this issue, this application proposes an improved pressurized unit for N-vinylcaprolactam synthesis, aiming to optimize the performance of existing equipment through automated control to meet the high standards and stringent requirements of industrial production.

[0006] Therefore, existing technologies need further development. Utility Model Content

[0007] This utility model provides a pressurization device for an N-vinylcaprolactam reactor, the specific implementation of which is as follows: A pressurizing device for an N-vinylcaprolactam reactor, wherein the reactor is provided with an air inlet and a first pressure measuring device for measuring the pressure inside the reactor, the pressurizing device includes a buffer tank containing gaseous raw materials, the air outlet of the buffer tank is connected to the air inlet of the reactor through a first pipeline, a booster pump, a flow meter, and a first regulating valve are sequentially arranged on the first pipeline, the booster pump is located between the air outlet of the buffer tank and the flow meter, the booster pump is provided with an instrument gas inlet, the instrument gas inlet is connected to an instrument gas supply device through a second pipeline, a solenoid valve is arranged on the second pipeline, and the solenoid valve is connected to the pressure measuring device via a signal.

[0008] Furthermore, the flow meter is connected to the first regulating valve via a signal.

[0009] Furthermore, the buffer tank is equipped with a gas feed inlet and a second pressure measuring device for measuring the pressure inside the buffer tank. The gas feed inlet is connected to the gas feed supply equipment via a third pipeline. A second regulating valve is installed on the third pipeline, and the second pressure measuring device is signal-connected to the second regulating valve.

[0010] Furthermore, a pressure reducing valve is also provided on the second pipeline between the solenoid valve and the instrument gas supply device.

[0011] Furthermore, a first check valve is provided on the first pipeline between the booster pump and the outlet of the buffer tank, and a second check valve is provided on the first pipeline between the flow meter and the first regulating valve.

[0012] Furthermore, the buffer tank is equipped with a feed inlet pipe, one end of which is connected to the gas raw material inlet, and the other end extends to the bottom of the buffer tank.

[0013] Furthermore, a flame arrester is also installed on the third pipeline between the second regulating valve and the gas raw material supply equipment.

[0014] Furthermore, the reactor is equipped with an air inlet pipe, one end of which is connected to the air inlet, and the other end extends to the bottom of the reactor.

[0015] Furthermore, the buffer tank is also equipped with a first safety valve, and the reaction vessel is also equipped with a second safety valve.

[0016] Beneficial effects: 1. The pressurization device of the reactor achieves precise control of the internal pressure of the reactor through a sophisticated control system. The first pressure measuring device monitors the internal pressure of the reactor in real time. Once the pressure is found to be lower than the preset lower limit, the first pressure measuring device will immediately send a signal to the solenoid valve, causing the solenoid valve to open and allowing instrument gas to enter the booster pump. The instrument gas provides power to the booster pump, thereby compressing the gaseous raw material in the buffer tank and pushing it into the reactor to replenish the required gas pressure in time. The whole process is automatically adjusted to ensure sufficient gas supply throughout the reaction process and reduce the hidden dangers caused by human error on site. 2. The flow meter works in conjunction with the first regulating valve to ensure that the gaseous raw materials can participate in the reaction at a stable and uniform rate, which improves the controllability of the reaction and the stability of product quality, and ensures the safe and stable reaction process. This series of operations does not require frequent manual intervention, reduces the uncertainty of human operation, and improves the automation level and production efficiency of the system. 3. When the flow meter detects that the acetylene flow rate deviates from the preset value, it will send a signal to the regulating valve, causing the valve opening to change, thereby adjusting the acetylene supply and ensuring the stability of the acetylene concentration in the reactor. This closed-loop control mechanism greatly improves the controllability and efficiency of the reaction process, reduces acetylene waste caused by human error or equipment fluctuations, and also helps maintain the optimal state of the reaction. Attached Figure Description

[0017] Figure 1 This is a diagram of the pressurization device for the N-vinylcaprolactam reactor of this utility model; Figure 2 This is a schematic diagram of the reactor structure of this utility model; Figure 3 This is a schematic diagram of the buffer tank structure of this utility model.

[0018] The above figures include the following reference numerals: 1. Buffer tank; 11. Gas outlet; 12. Second pressure measuring device; 13. First safety valve; 14. Gas feed inlet; 15. Feed inlet bottom pipe; 2. First pipeline; 21. Booster pump; 211. Instrument gas inlet; 22. Flow meter; 23. First regulating valve; 24. First check valve; 25. Second check valve; 3. Reactor; 31. First pressure measuring device; 32. Second safety valve; 33. Gas inlet; 34. Gas inlet bottom pipe; 35. Feed inlet; 36. Stirring device; 4. Instrument gas supply device; 5. Gas feed supply equipment; 6. Second pipeline; 61. Solenoid valve; 62. Pressure reducing valve; 7. Third pipeline; 71. Second regulating valve; 72. Flame arrester. Detailed Implementation

[0019] The specific embodiments of this utility model are described below with reference to the accompanying drawings and examples: It should be noted that the structures, proportions, sizes, etc. shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0020] Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0021] According to an embodiment of the present invention, a pressurization device for an N-vinylcaprolactam reactor is provided, comprising: A pressurization device for a reaction vessel 3, such as Figure 1 The reactor 3 is equipped with an air inlet 33 and a first pressure measuring device 31 for measuring the pressure inside the reactor 3. The pressurizing device includes a buffer tank 1 containing gaseous raw materials. The air outlet 11 of the buffer tank 1 is connected to the air inlet 33 of the reactor 3 through a first pipeline 2. A booster pump 21, a flow meter 22, and a first regulating valve 23 are sequentially arranged on the first pipeline 2. The booster pump 21 is located between the air outlet 11 of the buffer tank 1 and the flow meter 22. The booster pump 21 is equipped with an instrument gas inlet 211. The instrument gas inlet 211 is connected to the instrument gas supply device 4 through a second pipeline 6. A solenoid valve 61 is arranged on the second pipeline 6. The solenoid valve 61 is connected to the first pressure measuring device 31 through a signal connection. The pressurization device of reactor 3 achieves precise control of the internal pressure of reactor 3 through a sophisticated control system. The first pressure measuring device 31 monitors the pressure inside reactor 3 in real time. Once the pressure is detected to be lower than the preset lower limit, the first pressure measuring device 31 immediately sends a signal to the solenoid valve 61, causing the solenoid valve 61 to open and allowing instrument gas to enter the booster pump 21. The instrument gas provides power to the booster pump 21, thereby compressing the gaseous raw material in buffer tank 1 and pushing it into reactor 3 to replenish the required gas pressure in a timely manner. The entire process is automatically adjusted to ensure a sufficient supply of acetylene gas throughout the reaction process, reducing the potential risks caused by human error on site. The booster pump 21 is powered by instrument gas, making it simple to operate and easy to maintain, greatly saving production costs.

[0022] In addition, the upper and lower pressure limits inside reactor 3 are adjustable, and the pressure range of acetylene inside the reactor can be precisely controlled by starting and stopping the booster pump 21; such as Figure 2 The reactor 3 also includes a feed inlet 35, which facilitates the addition of other materials required for the reaction.

[0023] The flow meter 22 is connected to the first regulating valve 23 via a signal. By setting the flow rate, the flow meter 22 feeds back to the first regulating valve 23 to adjust the valve opening. The flow meter 22 and the first regulating valve 23 work together to ensure that the gaseous raw material is added to the reaction system at a constant rate, avoiding changes in reaction conditions caused by pressure fluctuations, maintaining the stability and continuity of the reaction. This series of operations does not require frequent manual intervention, reducing the uncertainty of human operation and improving the automation level and production efficiency of the system.

[0024] like Figure 3 The buffer tank 1 is equipped with a gas feed inlet 14 and a second pressure measuring device 12 for measuring the pressure inside the buffer tank 1. The gas feed inlet 14 is connected to the gas supply equipment 5 via a third pipeline 7. A second regulating valve 71 is installed on the third pipeline 7, and the second pressure measuring device 12 is signal-connected to the second regulating valve 71. The signal connection between the second pressure measuring device 12 and the second regulating valve 71 enables automatic pressure maintenance of the buffer tank 1. When the pressure in the buffer tank 1 is insufficient, the system automatically opens the second regulating valve 71 to replenish the gas, which can solve the problem of automatic adjustment of the gas feed pressure inside the tank, ensuring sufficient gas supply pressure throughout the reaction process and reducing the potential hazards caused by human error on site. Before the gas feed is introduced into the buffer tank 1, the air in the system is replaced with nitrogen in advance to eliminate the risk of explosion and ensure the safe use of the buffer tank 1.

[0025] A pressure reducing valve 62 is also provided on the second pipeline 6 between the solenoid valve 61 and the instrument gas supply device 4. The pressure reducing valve 62 ensures that the instrument gas pressure is within a safe range, preventing overpressure damage to the booster pump 21 or the solenoid valve 61, extending the equipment life, and improving the safety and stability of operation.

[0026] A first check valve 24 is provided on the first pipeline 2 between the booster pump 21 and the outlet 11 of the buffer tank 1, and a second check valve 25 is provided on the first pipeline 2 between the flow meter 22 and the first regulating valve 23. The check valves effectively prevent gas backflow, avoid contamination or equipment failure caused by reactant backflow, ensure the unidirectionality of gas flow, and protect the integrity and safety of the system.

[0027] The buffer tank 1 is equipped with a feed inlet pipe 15. One end of the feed inlet pipe 15 is connected to the gas feed port 14, and the other end extends to the bottom of the buffer tank 1. The feed inlet pipe 15 is fixed to the tank wall by a triangular fixing bracket. A small hole is left at the bottom of the feed inlet pipe 15, and three sets of small holes are reserved on the pipe wall. The small holes are oriented upward at 120 degrees. The feed inlet pipe 15 allows gas to enter from the bottom of the buffer tank 1, which promotes uniform gas distribution and pressure buffering, reduces gas source fluctuations, and provides a more stable gas supply for the reactor 3.

[0028] A flame arrester 72 is also provided on the third pipeline 7 between the second regulating valve 71 and the gas raw material supply equipment 5. The flame arrester 72 provides additional safety protection, prevents backfire from spreading to the gas source equipment, reduces the risk of fire or explosion, and is particularly suitable for handling flammable gases (such as acetylene), enhancing the overall safety of the system.

[0029] The reactor 3 is equipped with an inlet pipe 34, one end of which is connected to an inlet 33, and the other end extends to the bottom of the reactor 3. The inlet pipe 34 is fixed to the reactor wall by a triangular bracket. There are air holes at the bottom of the inlet pipe 34, and three sets of air holes are reserved on the pipe wall, with the air holes facing upward at 120 degrees. The reactor 3 is also equipped with a stirring device 36. The inlet pipe 34 introduces gas into the bottom of the reactor 3, and under the stirring action of the stirring device 36, fine bubbles are formed, which increases the gas-liquid contact area, improves the mass transfer efficiency and reaction rate, and makes the acetylene gas more dispersed and mixed with the system in the synthesis reaction system, thereby improving the utilization rate of raw materials and the yield of products.

[0030] The buffer tank 1 is also equipped with a first safety valve 13, and the reaction vessel 3 is also equipped with a second safety valve 32. As a protection device against pressure over-limit, the safety valve can automatically release pressure when the pressure rises abnormally, preventing equipment damage or safety accidents, providing key safety assurance for the system, and ensuring absolute operational safety.

[0031] The equipment, pipelines, fittings, and related instrument accessories used in this utility model are all made of stainless steel 304 or 316. It should be noted that the buffer tank 1 and the corresponding pipeline vent valves adopt double valve venting, the synthesis reactor motor, and the related instruments have an explosion-proof rating of ExdⅡCT4 or above. This device can adopt a DCS control system or a PLC control system. It should be noted that different control systems can be selected according to different scenarios.

[0032] This invention takes the synthesis of N-vinylcaprolactam as an example, with acetylene as the gaseous raw material.

[0033] Acetylene, the gaseous feedstock, originates from gaseous feedstock supply equipment 5 and passes through third pipeline 7. On third pipeline 7, the acetylene first passes through flame arrester 72 to prevent backfire risk. Subsequently, the acetylene passes through second regulating valve 71, which is controlled by second pressure measuring device 12 on buffer tank 1. Acetylene enters buffer tank 1 through gaseous feedstock inlet 14 and from the bottom of the tank via feed bottom pipe 15 to promote uniform acetylene distribution. Second pressure measuring device 12 monitors the pressure inside buffer tank 1 in real time. When the pressure falls below a set value, a signal is sent to open second regulating valve 71, automatically replenishing the gaseous feedstock to maintain stable pressure inside buffer tank 1. Buffer tank 1 is also equipped with a first safety valve 13 for overpressure protection. The process is initiated when reactor 3 needs pressurization or gaseous feedstock replenishment. First pressure measuring device 31 on reactor 3 monitors the pressure inside the reactor in real time. When the pressure falls below a set lower limit, a signal is sent. This signal is sent to solenoid valve 61 installed on second pipeline 6, causing it to open. Instrument gas originates from instrument gas supply device 4, flows through second pipeline 6, and first passes through pressure reducing valve 62 to stabilize the pressure within a safe range. Then, it passes through the opened solenoid valve 61. Instrument gas enters booster pump 21 through instrument gas inlet 211, providing power. The booster pump 21, now operational, draws gaseous raw material from outlet 11 of buffer tank 1. The gas enters booster pump 21 through first check valve 24 on first pipeline 2. The pressurized gaseous raw material continues to flow along first pipeline 2, passing through flow meter 22. Flow meter 22 monitors and sends a feedback acetylene flow signal to first regulating valve 23, maintaining a constant gas flow rate by adjusting the opening of first regulating valve 23. Acetylene then enters reactor 3 through second check valve 25 and inlet 33. Inside reactor 3, acetylene is guided to the bottom of the reactor through inlet pipe 34 and released through vents on its bottom and sides. Under the stirring action of the stirring device 36, acetylene gas is dispersed into fine bubbles, which are fully mixed with the materials in the reactor and participate in the reaction. The first pressure measuring device 31 continuously monitors the pressure. When the pressure reaches the preset upper limit, a signal is sent to close the solenoid valve 61, cutting off the instrument gas supply, stopping the booster pump 21, and suspending gas delivery. The reactor 3 is also equipped with a second safety valve 32 for overpressure protection.

[0034] Many other changes and modifications can be made without departing from the concept and scope of this utility model. It should be understood that this utility model is not limited to the specific embodiments, and the scope of this utility model is defined by the appended claims.

Claims

1. A pressurizing device for an N-vinylcaprolactam reactor, characterized in that, The reactor is equipped with an air inlet and a first pressure measuring device for measuring the pressure inside the reactor. The first pressure measuring device includes a buffer tank containing gaseous raw materials. The air outlet of the buffer tank is connected to the air inlet of the reactor through a first pipeline. A booster pump, a flow meter, and a first regulating valve are sequentially arranged on the first pipeline. The booster pump is located between the air outlet of the buffer tank and the flow meter. The booster pump is equipped with an instrument gas inlet. The instrument gas inlet is connected to an instrument gas supply device through a second pipeline. A solenoid valve is arranged on the second pipeline. The solenoid valve is connected to the first pressure measuring device via a signal connection.

2. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, The flow meter is connected to the first regulating valve via a signal.

3. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, The buffer tank is equipped with a gas feed inlet and a second pressure measuring device for measuring the pressure inside the buffer tank. The gas feed inlet is connected to the gas feed supply equipment via a third pipeline. A second regulating valve is installed on the third pipeline, and the second pressure measuring device is signal-connected to the second regulating valve.

4. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, A pressure reducing valve is also installed on the second pipeline between the solenoid valve and the instrument gas supply device.

5. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, A first check valve is provided on the first pipeline between the booster pump and the outlet of the buffer tank, and a second check valve is provided on the first pipeline between the flow meter and the first regulating valve.

6. The pressurizing device for the N-vinylcaprolactam reactor according to claim 3, characterized in that, The buffer tank is equipped with a feed inlet pipe, one end of which is connected to the gas feed port, and the other end extends to the bottom of the buffer tank.

7. The pressurizing device for the N-vinylcaprolactam reactor according to claim 3, characterized in that, A flame arrester is also installed on the third pipeline between the second regulating valve and the gas raw material supply equipment.

8. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, The reactor is equipped with an air inlet pipe, one end of which is connected to the air inlet, and the other end extends to the bottom of the reactor.

9. The pressurizing device for the N-vinylcaprolactam reactor according to claim 1, characterized in that, The buffer tank is also equipped with a first safety valve, and the reaction vessel is also equipped with a second safety valve.

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