An online unblocking device for gas phase pipeline of esterification kettle

Abstract

The application discloses an online dredging device for a gas phase pipeline of an esterification kettle, which comprises an esterification kettle body, a gas phase pipeline body, a nitrogen input pipe, a first control valve, and a nitrogen pipe, the outer end of the first control valve is provided with a first three-way pipe, a switch valve is arranged between the first three-way pipe and the nitrogen pipe, the other end of the first three-way pipe is provided with a second control valve, the outer end of the second control valve is provided with a second three-way pipe, the two ends of the second three-way pipe are respectively connected with an air extraction device and a detachable metal dredging rod, and the insertion end of the metal dredging rod can be inserted into the gas phase pipeline body along the second three-way pipe, so that the scaling blockage between the gas phase pipeline body and the esterification kettle body can be dredged. The device can solve the problem that the second esterification kettle is not smoothly fed due to the internal incoordination of the gas phase pipeline caused by serious scaling between the esterification kettle and the gas phase pipeline in a polyester production device, and avoid the situation that the reaction in the second esterification kettle is excessive or even forced to stop due to the high pressure in the esterification kettle.

Description

Technical Field

[0001] This invention relates to the field of esterification reactor equipment technology, specifically to an online unblocking device for the gas phase pipeline of an esterification reactor. Background Technology

[0002] Currently, many polyester manufacturers in my country use the production process developed by the China Textile Research Institute. The entire polyester production process is divided into esterification and polycondensation stages. The esterification stage involves two reaction processes: terephthalic acid (PTA) and ethylene glycol (EG) are mixed into a slurry and then fed into the first esterification reactor, where the esterification rate reaches approximately 92%. The material then enters the second esterification reactor for further esterification, achieving an esterification rate of approximately 97%. Only then can the esterified product proceed to the subsequent polycondensation reaction. If the esterification rate does not meet the requirements, it will severely affect product quality. However, a large amount of water, a byproduct of the esterification reaction, is generated. This water is distilled through a vapor pipe at the top of the esterification reactor and then distilled in the 13-CO1 process tower. When this water is distilled, it carries a certain amount of EG, as well as unreacted PTA powder and other impurities from the raw materials. Relatively speaking, the water by-product is mainly generated in the first esterification reactor and is produced in large quantities, while the water produced in the second esterification reactor is very small. Therefore, the gas phase pipeline of the second esterification reactor may become blocked due to scale buildup, causing the pressure inside the esterification reactor to rise. This can not only cause excessive reaction in the second esterification reactor, but also obstruct the flow of material from the first to the second esterification reactor, affecting the output and product quality of the unit. In severe cases, it may even force the unit to shut down. Moreover, it is impossible to clean the gas phase pipeline online after dismantling during normal production. The unit must be shut down and cooled before manual entry into the reactor can be carried out for cleaning, which is both difficult and costly. Therefore, online emergency cleaning of the gas phase pipeline of the esterification reactor is very important. Summary of the Invention

[0003] In order to solve one or more technical problems existing in the prior art, the purpose of this application is to provide an online unblocking device for the gas phase pipeline of the esterification kettle, which can solve the problem of poor material flow in the second esterification kettle caused by severe scaling between the esterification kettle and the gas phase pipeline in the polyester production unit. It can also prevent the pressure inside the esterification kettle from being too high, which could lead to excessive reaction or even forced shutdown of the second esterification kettle. The device has a simple structure and is easy to operate.

[0004] To solve the aforementioned technical problems, this application adopts the following technical solution:

[0005] An online unblocking device for the gas phase pipeline of an esterification reactor includes an esterification reactor body, a gas phase pipeline body located on top of the esterification reactor body, a nitrogen input pipe inclinedly arranged on the gas phase pipeline body, a first control valve located at the outer end of the nitrogen input pipe, and a nitrogen pipe connected to the first control valve. The outer end of the first control valve is provided with a first tee pipe, one end of which is provided with a switch valve. The nitrogen pipe is connected to one end of the first tee pipe through the switch valve. The other end of the first tee pipe is provided with a second control valve, and the outer end of the second control valve is provided with a second tee pipe. One end of the second tee pipe is connected to a suction device, and the other end of the second tee pipe is inserted with a detachable metal unblocking rod. The extended end of the metal unblocking rod can extend into the gas phase pipeline body along the second tee pipe, the open second control valve, the first tee pipe, the open first control valve, and the nitrogen input pipe, thereby unblocking the scale and blockage between the gas phase pipeline body and the esterification reactor body.

[0006] Preferably, both the first tee pipe and the second tee pipe consist of a straight pipe and an inclined pipe, and the nitrogen pipe and the connecting pipe of the suction device are both connected to the port of the inclined pipe. The metal drain rod is arranged in a straight inclined line through the first tee pipe and the second tee pipe.

[0007] Preferably, the metal drain cleaning rod is made of stainless steel with a diameter of 4-6 mm and a length of 5-8 meters. During the dredging process, the length of the metal drain cleaning rod exposed outside the second and third-way pipe is not less than 3 meters.

[0008] Preferably, the gas extraction device includes a vacuum pump and a high-temperature resistant pipe disposed between the vacuum pump and the second three-way pipe, and most of the high-pressure gas discharged outward through the second control valve is extracted by the vacuum pump.

[0009] Preferably, one end of the second three-way pipe is provided with a horn-shaped guide port, and one end of the metal drain rod is inserted through the horn-shaped guide port.

[0010] Preferably, an operating platform is provided on one side of the esterification reactor body, and a baffle is provided on one side of the operating platform. The baffle has a through hole with a diameter of no more than 5 cm. The axial extension distance between the baffle and the horn-shaped guide port is 2 to 2.5 meters. One end of the metal unblocking rod is inserted into the second three-way pipe through the through hole. The high-pressure gas ejected through the second three-way pipe is blocked by the baffle.

[0011] Preferably, the end of the metal drain rod is provided with a stop portion, the width of which is greater than the width of the through hole.

[0012] Preferably, a pressure gauge is provided on the first tee pipe, the first control valve is in a normally open state, the second control valve and the switch valve are in a normally closed state, and the pressure in the gas phase pipeline body is detected by the pressure gauge.

[0013] Preferably, a pressure detection device is provided between the second control valve and the second three-way pipe. The pressure detection device includes an installation pipe with one end fixed to the second control valve and a third control valve located at the end of the installation pipe. The end of the second three-way pipe is connected to the third control valve.

[0014] Preferably, the first control valve, the second control valve, and the third control valve are all ball valves with a pipe diameter of DN25.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The cleaning device consists of a first three-way pipe, a second control valve, a second three-way pipe, an air extraction device, and a metal cleaning rod. The first three-way pipe facilitates the connection to the original nitrogen pipe, while the metal cleaning rod allows for direct cleaning of scale between the esterification reactor and the gas phase pipeline without shutting down the machine. This effectively solves the problem of blockages caused by scale buildup in the gas phase pipeline of the second esterification reactor during the esterification reaction, leading to high pressure inside the esterification reactor, impaired material flow from the first to the second esterification process, and affecting the output and product quality of the equipment. Furthermore, the cleaning method is simple and convenient, easy to operate, has low difficulty in cleaning, and is highly safe, effectively reducing production costs. It has achieved unexpected results in addressing the difficult problem of blockages in the esterification reactor and gas phase pipeline during the esterification reaction process. Furthermore, the high-temperature and high-pressure gas ejected during the cleaning process can be mostly actively extracted through the extraction device connected to the second and third ducts, effectively solving the safety hazard caused by the external spraying of ethylene glycol vapor during the unblocking process; it not only protects the safety of operators but also improves environmental safety, avoiding the generation of high-temperature environments. The overall structure design is simple, the manufacturing cost is low, and the operation is easy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0018] Figure 2 This is a side view of the first tee pipe and the second tee pipe in this invention;

[0019] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the present invention, showing the positional relationship between the baffle and the metal drain rod;

[0020] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of the present invention, showing the installation position of the pressure gauge;

[0021] Figure 5 This is a schematic diagram of the structure of Embodiment 4 of the present invention, showing the installation position of the pressure detection device;

[0022] Figure 6 This is a cross-sectional view of the connection between the second tee pipe and the flared guide port in this invention;

[0023] In the diagram: 1. Esterification reactor body; 2. Gas phase pipeline body; 3. Nitrogen input pipe; 4. First tee pipe; 5. Second control valve; 6. Second tee pipe; 7. Horn-shaped guide port; 8. Metal drain rod; 9. Switch valve; 10. Nitrogen pipe; 11. High-temperature resistant pipe; 12. Vacuum pump; 13. Evacuation device; 14. First control valve; 15. Straight pipe; 16. Inclined pipe; 17. Through hole; 18. Stop part; 19. Baffle; 20. Operating table; 21. Pressure gauge; 22. Pressure detection device; 23. Third control valve; 24. Mounting pipe; 25. Stainless steel pipe. Detailed Implementation

[0024] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0025] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0026] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0027] Example 1:

[0028] like Figure 1As shown, an online unblocking device for the gas phase pipeline of an esterification reactor includes an esterification reactor body 1, a gas phase pipeline body 2 located at the top of the esterification reactor body 1, a nitrogen input pipe 3 inclinedly arranged on the gas phase pipeline body 2, a first control valve 14 located at the outer end of the nitrogen input pipe 3, and a nitrogen pipe 10 connected to the first control valve 14. The device is characterized in that: a first three-way pipe 4 is provided at the outer end of the first control valve 14, and a switch valve 9 is provided at one end of the first three-way pipe 4. The nitrogen pipe 10 is connected to one end of the first three-way pipe 4 through the switch valve 9. The other end is provided with a second control valve 5, and the outer end of the second control valve 5 is provided with a second three-way pipe 6. One end of the second three-way pipe 6 is connected to a suction device 13, and the other end of the second three-way pipe 6 is inserted with a detachable metal cleaning rod 8. The extended end of the metal cleaning rod 8 can extend into the gas phase pipeline body 2 along the second three-way pipe 6, the open second control valve 5, the first three-way pipe 4, the open first control valve 14, and the nitrogen input pipe 3, thereby clearing the scale blockage between the gas phase pipeline body 2 and the esterification reactor body 1.

[0029] To address the problem of poor material flow in the second esterification reactor caused by severe scaling between the esterification reactor and the gas phase pipeline in the polyester production unit, an online unblocking device was installed at the outer end of the nitrogen input pipe 3. This device consists of a first three-way pipe 4, a second control valve 5, a second three-way pipe 6, an extraction device 13, and a metal unblocking rod 8. The first three-way pipe 4 facilitates connection to the original nitrogen pipe 10, while the metal unblocking rod 8 allows for direct, non-stop cleaning of the scaling between the esterification reactor and the gas phase pipeline. Furthermore, the high-temperature, high-pressure gas ejected during the cleaning process can be largely actively extracted through the extraction device 13 connected to the second three-way pipe 6, enhancing the safety of unblocking personnel. The overall structure is simple, with low manufacturing costs and easy operation. In actual operation, under normal circumstances, the switch valve 9, the first control valve 14, and the second control valve 5 are all in the closed state. When the esterification reactor body 1 needs to be shut down and nitrogen is introduced, the switch valve 9 and the first control valve 14 are activated so that the nitrogen is injected through the nitrogen pipe 10 and can enter the esterification reactor body 1 in sequence along the switch valve 9, the first three-way pipe 4, the first control valve 14, and the gas phase pipeline body 2. During the process of replenishing nitrogen, the second control valve 5 can prevent the nitrogen from being directly discharged to the outside.When severe scaling between the esterification reactor and the gas phase pipeline obstructs the flow of material inside the gas phase pipeline body 2, the pressure gauge on the esterification reactor body 1 will show an increase in pressure. When the pressure gauge shows an increase in pressure, it needs to be cleared. During the cleaning and clearing of the scaling between the esterification reactor and the gas phase pipeline, the switch valve 9 is in the closed state, and the second control valve 5 and the first control valve 14 are in the normally open state. At this time, the interiors of the second three-way pipe 6, the second control valve 5, the first three-way pipe 4, the first control valve 14, and the nitrogen input pipe 3 are unobstructed. When one end of the metal clearing rod 8 is inserted into the second... After the three-way pipe 6, it can be directly inserted into the scale between the esterification reactor and the gas phase pipeline along the internal pipeline of the second three-way pipe 6, the second control valve 5, the first three-way pipe 4, the first control valve 14, and the nitrogen input pipe 3. The scale is loosened and cleaned through the end of the metal cleaning rod 8, thereby achieving unobstructed flow between the esterification reactor and the gas phase pipeline. During the unblocking process, because the esterification reactor body 1 is under high pressure, high-pressure gas will inevitably be ejected outward along the pipeline through which the metal cleaning rod 8 is inserted at the moment of unblocking and after unblocking. This poses a risk of high-temperature burns to the unblocking personnel. To prevent large amounts of high-pressure gas from impacting the personnel along the metal unclogging rod 8, a second three-way pipe 6 connected to an extraction device 13 is installed at the outer end of the second control valve 5. During the unclogging process, simply opening the extraction device 13 allows most of the high-temperature, high-pressure gas entering the second three-way pipe 6 along the channel to enter the extraction device 13 through the branch, thus reducing the amount of high-temperature, high-pressure gas discharged from the insertion end of the metal unclogging rod 8 in the second three-way pipe 6. This protects the safety of the operators and improves environmental safety, preventing the generation of high-temperature environments. Simultaneously, this also applies to the esterification reactor and... When clearing scale buildup in the gas phase pipelines, the clearing can be carried out at any time during equipment operation without the need for shutdown. This effectively solves the problem of blockages caused by scale buildup in the gas phase pipelines of the second esterification reactor during the esterification reaction, which leads to high pressure inside the esterification reactor, causing poor material flow from the first to the second esterification process, affecting equipment output and product quality. Moreover, the clearing method is simple and convenient, easy to operate, low in difficulty, and safe, effectively reducing production costs. It has an unexpected effect on the difficult problem of clearing blockages in the esterification reactor and gas phase pipelines during the esterification reaction process.

[0030] Further improvements include, for example Figure 2 As shown, both the first tee pipe 4 and the second tee pipe 6 consist of a straight pipe 15 and an inclined pipe 16. The connecting pipes of the nitrogen pipe 10 and the air extraction device 13 are connected to the port of the inclined pipe 16. The metal unblocking rod 8 is arranged in a straight inclined line through the first tee pipe 4 and the second tee pipe 6.

[0031] Both the first three-way pipe 4 and the second three-way pipe 6 consist of a straight pipe 15 and an inclined pipe 16. The connecting pipes of the nitrogen pipe 10 and the suction device 13 are connected to the port of the inclined pipe 16. This allows the internal pipeline to be in a straight state when the metal cleaning rod 8 is inserted into the gas phase pipeline body 2. This makes the insertion of the metal cleaning rod 8 more convenient and smooth, avoiding the phenomenon of bending and jamming in the middle. It also allows the high-temperature and high-pressure gas to flow into the suction device 13 more smoothly. Furthermore, it allows the dirt discharged along the high-temperature and high-pressure gas to be discharged directly out along the straight pipe 15, preventing it from entering the suction device 13 and making the operation of the suction device 13 more stable. The angle between the inclined tube 16 and the outer end of the straight tube 15 is about 30°. When nitrogen is injected, the flow of nitrogen is smoother. At the same time, it makes the flow of high-temperature and high-pressure gas injected into the straight tube 15 into the pumping device 13 smoother. This reduces the amount of high-temperature and high-pressure gas discharged from the outermost end of the second three-way pipe 6, thus maximizing the safety of the operator and preventing the high-temperature and high-pressure gas from impacting the operator.

[0032] A further improvement is that the metal unblocking rod 8 is made of stainless steel with a diameter of 4-6 mm, the length of the metal unblocking rod 8 is 5-8 meters, and the length of the metal unblocking rod 8 exposed outside the second three-way pipe 6 during the unblocking process is not less than 3 meters.

[0033] Although most of the high-temperature, high-pressure gas inside the esterification reactor body 1 is removed by the suction device 13 when it is discharged outward along the second three-way pipe 6, it has been found in actual operation that the high-temperature, high-pressure gas discharged from the second three-way pipe 6 can still spray outward at least 2 to 3 meters. Therefore, in order to ensure the safety of operators, the length of the metal cleaning rod 8 is generally about 5 to 6 meters. In particular, the length of the metal cleaning rod 8 exposed outside the second three-way pipe 6 during the cleaning process should not be less than 3 meters to avoid the occurrence of production safety accidents. The metal cleaning rod 8 is made of stainless steel with a diameter of 4 to 6 mm. Among them, 6 mm stainless steel rods are generally used, which have better rigidity, better cleaning effect, and moderate weight, so that there will be no difficulty in operation or bending during operation.

[0034] A further improvement is that the metal drain rod 8 includes a cylindrical stainless steel section and a threaded steel section. The length of the stainless steel section is about 3 to 4 meters, and the length of the threaded steel section is about 2.5 to 3 meters. The stainless steel section and the threaded steel section are fixed together by welding.

[0035] Because cylindrical stainless steel rods are too long and prone to bending during the unblocking process, and to avoid the problem of easy bending of the whole, the metal unblocking rod is divided into two parts. The front unblocking part is a stainless steel section with a diameter of 6mm and a length of about 3 to 4 meters, generally 3.5 meters. This ensures both effective insertion efficiency and a certain degree of rigidity. The rear end is made of threaded steel section welded together, which has better overall rigidity and is less prone to bending. At the same time, it can effectively avoid the problem of bending of the exposed part due to internal resistance during the unblocking process.

[0036] A further improvement is that the gas extraction device 13 includes a vacuum pump 12 and a high-temperature resistant pipe 11 disposed between the vacuum pump 12 and the second three-way pipe 6, and most of the high-pressure gas discharged to the outside through the second control valve 5 is extracted by the vacuum pump 12.

[0037] The air extraction device 13 consists of a vacuum pump 12 and a high-temperature resistant tube 11, which has a simpler structure and makes it easier and more convenient to extract high-temperature and high-pressure gas that has entered the second three-way pipe 6.

[0038] A further improvement is made in that one end of the second three-way pipe 6 is provided with a horn-shaped guide port 7, and one end of the metal unblocking rod 8 is inserted through the horn-shaped guide port 7.

[0039] Because the diameter of the second three-way pipe 6 is small, when there is a frame around the second three-way pipe 6, the operator can climb onto the frame and manually insert one end of the metal drain rod 8 into the second three-way pipe 6. However, when the end of the second three-way pipe 6 is relatively high, in order to facilitate the precise insertion of the metal drain rod 8 into the second three-way pipe 6 from a distance, a horn-shaped guide port 7 is installed at one end of the second three-way pipe 6. When inserting the metal drain rod 8, it is only necessary to insert it into the horn-shaped guide port 7 to achieve insertion and unblocking, which makes the operation easier and effectively solves the problem of difficult remote operation.

[0040] Example 2:

[0041] A further improvement based on any of the above embodiments is that an operating platform 20 is provided on one side of the esterification reactor body 1, and a baffle 19 is provided on one side of the operating platform 20. The baffle 19 has a through hole 17 with a diameter of no more than 5 cm. The axial extension distance between the baffle 19 and the horn-shaped guide port 7 is 2 to 2.5 meters. One end of the metal unblocking rod 8 is inserted into the second three-way pipe 6 through the through hole 17. The high-pressure gas ejected through the second three-way pipe 6 is blocked by the baffle 19.

[0042] To facilitate the operation of the metal drain rod 8, an operating platform 20 is built on one side of the esterification reactor body 1. The operating platform 20 can be an existing building. During the draining process, the operator only needs to stand on the operating platform 20 to easily extend the metal drain rod 8 outward and insert it into the second three-way pipe 6 along the axis. Since the insertion end of the second three-way pipe 6 will emit high-temperature and high-pressure gas, a baffle 19 needs to be installed on the operating platform 20 on one side of the second three-way pipe 6. The distance between the baffle 19 and the axial extension distance of the horn-shaped guide port 7 is 2 to 2.5 meters, which can effectively ensure the safety of the operator. A through hole 17 with a diameter of no more than 5cm is made on the baffle 19. During the unblocking process, the baffle 19 can effectively block the high temperature and high pressure gas, preventing impurities discharged along the gas from impacting the personnel and ensuring the safety of the personnel. The through hole 17 can also provide support and limit the metal unblocking rod 8 when it is inserted into the second three-way pipe 6, making the insertion of the metal unblocking rod 8 simpler and more convenient.

[0043] A further improvement is that a stainless steel pipe 25 with an inner diameter of 25mm is provided between the second three-way pipe 6 and the baffle 19, and the metal unblocking rod 8 is limited and supported by the stainless steel pipe 25 before being inserted into the second three-way pipe 6.

[0044] Because the distance between the baffle 19 and the second tee pipe 6 is relatively far, generally more than 3 meters, and the metal drain rod 8 is prone to bending, and the height of the esterification reactor body 1 is also relatively high, it is difficult to align the metal drain rod 8 when inserting it remotely, and the metal drain rod 8 is also prone to bending. Building another platform between the two would be costly. Therefore, a stainless steel pipe 25 with an inner diameter of 25mm is installed between the baffle 19 and the second tee pipe 6 using a bracket or similar means. One end of the metal drain rod 8 passes through the stainless steel pipe 25. 5. After setting a limit support, insert it into the second three-way pipe 6. The stainless steel pipe 25 shortens the suspended distance at both ends, thus solving the problem that the metal drain rod 8 cannot be accurately inserted after bending due to its thinness. At the same time, there will inevitably be internal resistance during insertion and unblocking. The stainless steel pipe 25 can also effectively increase the rigidity of the metal drain rod 8 between the second three-way pipe 6 and the baffle 19, avoiding bending. Generally, the length of the stainless steel pipe 25 is about 2 meters, so that the gap between the two ends is no more than 1 meter. The closer the distance, the better the effect.

[0045] A further improvement is that the end of the metal drain rod 8 is provided with a stop portion 18, the width of which is greater than the width of the through hole 17.

[0046] To prevent the metal drain cleaning rod 8 from falling off the worktable 20 during operation, a stop part 18 is added to the end of the metal drain cleaning rod 8. When the width of the stop part 18 is greater than the width of the through hole 17, even if the metal drain cleaning rod 8 falls outward, it can be suspended on the baffle 19 by the stop part 18. The stop part 18 is generally a ring or a metal rod structure, which is simpler and cheaper.

[0047] Example 3:

[0048] A further improvement based on any of the above embodiments is that a pressure gauge 21 is provided on the first tee pipe 4, the first control valve 14 is in a normally open state, the second control valve 5 and the switch valve 9 are in a normally closed state, and the pressure in the gas phase pipeline body 2 is detected by the pressure gauge 21.

[0049] Through careful study and practice of the structure of the second esterification reactor, we found that installing a pressure gauge 21 on the top of the reactor allows for real-time monitoring of pressure changes inside the reactor. An abnormally high pressure indicates a blockage in the gas phase pipeline, causing poor material flow. The pressure gauge 21 directly monitors the pressure inside the gas phase pipeline body 2 in real time. A decrease in pressure reading on the gauge indicates scaling between the gas phase pipeline and the esterification reactor. The pressure gauge 21 provides faster and more accurate real-time monitoring of the internal pipeline's flow, effectively preventing the pressure gauge on the esterification reactor body 1 from causing temporary flow obstruction due to insufficient sensitivity. This ensures stable and controllable production indicators and is a crucial structure for guaranteeing normal material flow in the second esterification reactor, maintaining the original pressure, and ensuring stable and efficient operation of the reactor.

[0050] Example 4:

[0051] A further improvement based on Embodiment 1 or Embodiment 2 is that a pressure detection device 22 is provided between the second control valve 5 and the second three-way pipe 6. The pressure detection device 22 includes an installation pipe 24 with one end fixed to the second control valve 5, a pressure gauge 21 provided on one side of the installation pipe 24, and a third control valve 23 provided at the end of the installation pipe 24. The end of the second three-way pipe 6 is connected to the third control valve 23.

[0052] The pressure detection device 22 is installed between the second control valve 5 and the second three-way pipe 6, and the end of the second three-way pipe 6 is connected to the third control valve 23. During operation, the first control valve 14 and the second control valve 5 are normally open, and the third control valve 23 and the switch valve 9 are normally closed. Thus, the pressure detection device 22 enables real-time monitoring of the internal pipeline's unobstructed flow. Compared with embodiment 3, when the pressure gauge 21 malfunctions and needs to be replaced, the entire pressure detection device 22 can be quickly replaced by closing the first control valve 14 and the second control valve 5, resulting in lower replacement costs. This is simpler, more convenient, and more flexible than replacing the entire first three-way pipe 4. In particular, when the pressure gauge 21 is replaced with a remote electronic pressure gauge, it can also achieve linkage monitoring with the system.

[0053] Meanwhile, the first control valve 14, the second control valve 5, and the third control valve 23 are all ball valves with a pipe diameter of DN25, which allows the metal drain rod 8 to be directly inserted during draining without damaging the valve body.

[0054] As can be seen from the above embodiments and background technology, the gas phase pipeline body 2 has a heat medium jacket, so it is impossible to stop the heat medium for treatment. Later, it was found that there is a DN25 diameter nitrogen inlet pipe 3 on the gas phase pipeline body 2. However, since the opening of the nitrogen inlet pipe 3 is inclined upward at a 45-degree angle to the gas phase pipeline body 2, it is impossible to use a thicker material to directly clear the blockage. At the same time, the esterification reactor body 1 is under positive pressure. When clearing the blockage, a large amount of ethylene glycol vapor will be sprayed outward, which will cause a flash explosion when it comes into contact with an open flame. Therefore, this operation is an extremely dangerous action. To solve the two difficulties, we use a 6mm diameter stainless steel material as a metal unblocking rod 8 (thinner materials are easier to bend and directly insert into the reactor). Then, we add a first three-way pipe 4 and a DN25 second control valve 5 to the outside end of the nitrogen input pipe 3. A second three-way pipe 6 is connected through the second control valve 5. A pipe is connected to the middle of the second three-way pipe 6 to directly introduce the vacuum pump 12 system of the condensation 14-PO3 pump 12 of the extraction device 13. One end of the first three-way pipe 4 is connected to the original nitrogen switch valve 9. The inlet end of the flared guide port 7 at the top of the second three-way pipe 6 is appropriately narrowed, such as... Figure 6 As shown, this way, most of the ethylene glycol vapor sprayed from the vessel during unclogging can be sucked away by the vacuum pump 12, significantly reducing the amount of ethylene glycol vapor on site. Simultaneously, because the unclogging material is thin and easily bent, and to prevent injury from any accidental spray of ethylene glycol vapor, operators must stay as far away from the pipe opening as possible during evacuation. Therefore, a DN25 pipe is fixed after the second / third-way pipe 6 as a protective sleeve for the unclogging material. The outer end of the protective sleeve is a flared guide port 7. Additionally, a baffle 19 is erected behind it, allowing operators to stand behind the baffle 19, further preventing injury from ethylene glycol vapor. In this way, all safety issues are ensured.

[0055] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. An online unblocking device for the gas phase pipeline of an esterification reactor, comprising an esterification reactor body (1), a gas phase pipeline body (2) disposed on the top of the esterification reactor body (1), a nitrogen input pipe (3) inclinedly disposed on the gas phase pipeline body (2), a first control valve (14) disposed at the outer end of the nitrogen input pipe (3), and a nitrogen pipe (10) connected to the first control valve (14), characterized in that: The first control valve (14) has a first three-way pipe (4) at its outer end. A switch valve (9) is located at one end of the first three-way pipe (4). The nitrogen pipe (10) is connected to one end of the first three-way pipe (4) via the switch valve (9). A second control valve (5) is located at the other end of the first three-way pipe (4). A second three-way pipe (6) is located at the outer end of the second control valve (5). A suction device (13) is connected to one end of the second three-way pipe (6). A detachable metal drain rod (8) is inserted into the other end of the second three-way pipe (6). The metal drain rod (8)... The insertion end can extend into the gas phase pipeline body (2) along the second three-way pipe (6), the open second control valve (5), the first three-way pipe (4), the open first control valve (14), and the nitrogen input pipe (3), thereby clearing the scale blockage between the gas phase pipeline body (2) and the esterification reactor body (1); the metal cleaning rod (8) is a stainless steel rod with a diameter of 4~6MM, the length of the metal cleaning rod (8) is 5~8 meters, and the length of the metal cleaning rod (8) exposed outside the second three-way pipe (6) during the cleaning process is not less than 3 meters.

2. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 1, characterized in that: Both the first tee pipe (4) and the second tee pipe (6) consist of a straight pipe (15) and an inclined pipe (16). The connecting pipes of the nitrogen pipe (10) and the air extraction device (13) are connected to the port of the inclined pipe (16). The metal unblocking rod (8) is set in a straight inclined position through the first tee pipe (4) and the second tee pipe (6).

3. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 2, characterized in that: The air extraction device (13) includes a vacuum pump (12) and a high-temperature resistant pipe (11) located between the vacuum pump (12) and the second three-way pipe (6). Most of the high-pressure gas discharged outward through the second control valve (5) is extracted by the vacuum pump (12).

4. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 2, characterized in that: One end of the second three-way pipe (6) is provided with a horn-shaped guide port (7), and one end of the metal drain rod (8) is inserted through the horn-shaped guide port (7).

5. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 4, characterized in that: An operating platform (20) is provided on one side of the esterification reactor body (1), and a baffle (19) is provided on one side of the operating platform (20). The baffle (19) has a through hole (17) with a diameter of no more than 5 cm. The distance between the axis of the baffle (19) and the horn-shaped guide port (7) is 2 to 2.5 meters. One end of the metal unblocking rod (8) is inserted into the second three-way pipe (6) through the through hole (17). The high-pressure gas ejected through the second three-way pipe (6) is blocked by the baffle (19).

6. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 5, characterized in that: The end of the metal drain rod (8) is provided with a stop part (18), the width of which is greater than the width of the through hole (17).

7. An online unblocking device for the vapor phase pipeline of an esterification reactor according to any one of claims 1 to 6, characterized in that: A pressure gauge (21) is provided on the first three-way pipe (4). The first control valve (14) is in the normally open state, and the second control valve (5) and the switch valve (9) are in the normally closed state. The pressure in the gas phase pipeline body (2) is detected by the pressure gauge (21).

8. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 7, characterized in that: A pressure detection device (22) is provided between the second control valve (5) and the second three-way pipe (6). The pressure detection device (22) includes an installation pipe (24) with one end fixed to the second control valve (5) and a third control valve (23) provided at the end of the installation pipe (24). The end of the second three-way pipe (6) is connected to the third control valve (23).

9. The online unblocking device for the vapor phase pipeline of an esterification reactor according to claim 8, characterized in that: The first control valve (14), the second control valve (5) and the third control valve (23) are all ball valves with a pipe diameter of DN25.

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