Cooling and filtering system for shaft seal lubricating oil of final polymerization kettle and online transformation method

Abstract

The invention discloses a final polymerization kettle shaft seal lubricating oil cooling and filtering system which comprises a filtering tank, a first conveying pipeline arranged between the filtering tank and a shaft seal lubricating oil outlet, a second conveying pipeline arranged between the filtering tank and an oil storage tank, a cooling device arranged in the filtering tank and an oil changing valve arranged below the filtering tank. Lubricating oil discharged from a shaft seal enters the filter tank through the first conveying pipeline to be filtered and then is conveyed into the oil storage tank through the second conveying pipeline, the high-temperature lubricating oil in the filter tank can be cooled after the cooling device is started, and the lubricating oil in the running state is discharged outwards through the oil change valve. New lubricating oil is added through the oil storage tank. The problems that the service life is short due to the fact that the temperature of shaft seal lubricating oil is too high and the lubricating oil is difficult to replace stably and completely are solved, the service life of the lubricating oil and the equipment production stability during lubricating oil replacement are guaranteed, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of polyester chemical production, in particular to a cooling and filtering system for a shaft seal lubricating oil of a final polymerization reactor. Background Art

[0002] The final polymerization kettle is the core equipment of polyester chemical equipment and the key equipment of the main material system. The oil station is an important auxiliary equipment for lubricating and cooling the shaft seal of the final polymerization kettle. It is mainly composed of oil storage tanks, oil pumps, filters, heat exchangers, oil pipelines, return oil pipelines and other major components. Needle valves and flow meters are installed on the return oil pipeline, and thermometers are installed on the oil storage tanks. The temperature of the lubricating oil in the oil storage tank is required to be 50-80°C. After the normal temperature cooling oil is poured into the oil storage tank, it is generally necessary to heat it to about 55°C through components such as the steam pipe at the bottom of the oil storage tank. Then, it is injected into the oil inlet of the oil seal through the oil pump to lubricate the shaft seal. After the hot oil is lubricated by the shaft seal, it flows out through the oil outlet of the shaft seal and flows back to the oil storage tank through the return oil pipeline. The structure is shown in patent CN201821861472.6.

[0003] In winter, when the temperature is relatively low, the lubricating oil discharged after lubrication at the final polymerization kettle shaft seal needs to be steam-heated to about 55°C and then circulated to the heat exchanger for recycling. However, when the temperature rises, the temperature of the lubricating oil discharged through the shaft seal will gradually increase. When the temperature reaches about 20°C, the temperature of the lubricating oil discharged after lubrication at the final polymerization kettle shaft seal and returned to the oil storage tank can reach above 80°C. Generally, the oil temperature often reaches about 90°C starting from March. When the temperature reaches above 38°C, the temperature of the lubricating oil discharged after lubrication at the final polymerization kettle shaft seal and returned to the oil storage tank can reach about 95°C. In weather above 42°C, the oil temperature can even exceed 100°C. Therefore, the frequency of lubricating oil replacement is higher under high temperature conditions.

[0004] However, if the lubricating oil is exposed to high temperature for a long time, it will accelerate the oxidation reaction of the lubricating oil, causing the oil to become thicker, the fluidity to deteriorate, and the formation of sludge and carbon deposits. Although there is a filter to filter, it is still easy to cause the needle valve to be blocked, and even the shaft seal may not be effectively lubricated. Ultimately, the shaft seal is not effectively lubricated for a long time and the mixer will be stuck. Therefore, at present, the lubricating oil of each final polymerization kettle generally needs to be replaced for the first time between the end of March and the beginning of April each year, and then it needs to be replaced every 2 to 3 months, 3 to 4 times a year. When the temperature is the highest, the lubricating oil needs to be replaced every 2 months. Each lubricating oil replacement costs about 17,000 yuan, resulting in high costs.

[0005] At the same time, the lubrication method for the final polymerization reactor shaft seal on the polyester plant is still mainly based on traditional lubrication. The lubricant needs to be manually replaced regularly through an online replacement method to dynamically replace impurities. During the replacement of the lubricant, although the lubricant can be discharged through the drain port at the bottom of the oil storage tank, the oil level in the tank is promptly introduced after it is emptied. However, this will more or less cause fluctuations in the equipment, which is not conducive to normal production. It is also impossible to scientifically determine the quality and quantity of the replacement, resulting in a huge waste of costs. If new oil is directly added while retaining a certain amount of the original lubricant, it will lead to problems with the purity of the oil, shortening the service life and easily causing blockage of the needle valve in the oil return line. Once the needle valve is blocked, it can only be intercepted and cleared by removing the oil return line from the shaft seal outlet. This method not only has certain safety risks for workers, but also results in waste of lubricant. Therefore, it is necessary to modify the final polymerization reactor shaft seal lubrication system to solve the problems of the existing equipment without affecting the shaft seal lubricant supply and equipment operation. Summary of the Invention

[0006] In order to solve certain technical problems existing in the prior art, one of the purposes of this application is to provide a final polymerization kettle shaft seal lubricating oil cooling and filtration system, which can solve the problems of short service life caused by excessively high temperature of the shaft seal lubricating oil and difficulty in stably replacing all the lubricating oil when replacing it, thereby ensuring the service life of the lubricating oil and the equipment production stability when replacing the lubricating oil, and reducing production costs.

[0007] The second purpose of this application is to provide an online modification method for the cooling and filtering system of the final polymerization kettle shaft seal lubricating oil, which can realize the addition and modification of the cooling and filtering system under the normal operation of the final polymerization kettle, so that the modified shaft seal lubricating oil can better control the oil temperature in summer, and the lubricating oil can be replaced more thoroughly and the operation is safer.

[0008] In order to solve the above existing technical problems, one of the objectives of this application is achieved by adopting the following technical solutions:

[0009] A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal comprises a filter tank, a first delivery pipe arranged between the filter tank and the shaft seal lubricating oil outlet, a second delivery pipe arranged between the filter tank and an oil storage tank, a cooling device arranged in the filter tank, and an oil change valve arranged below the filter tank. Lubricating oil discharged from the shaft seal enters the filter tank through the first delivery pipe for filtration and is then delivered to the oil storage tank through the second delivery pipe. The high-temperature lubricating oil in the filter tank can be cooled by turning on the cooling device. The lubricating oil in the operating state is discharged outward through the oil change valve, and new lubricating oil is added through the oil storage tank.

[0010] Preferably, the oil inlet of the filter tank is provided with a detachable filter screen, and the lubricating oil flowing out of the first delivery pipeline is filtered through the filter screen before flowing into the filter tank.

[0011] A detachable filter is added to the filter tank. When the lubricating oil enters the filter tank, it will be filtered through the filter to remove impurities in the lubricating oil, so that the filtered lubricating oil enters a relatively clean state. It can enter the oil storage tank better, pass through the filter below the oil storage tank for a second filtration, and finally circulate lubrication to the shaft seal.

[0012] Preferably, the oil seal outlet is provided with a three-way valve, the three-way valve is connected to the first delivery pipeline and the return oil pipeline, and the lubricating oil discharged by the oil seal flows into the first delivery pipeline or the return oil pipeline after being switched by the three-way valve.

[0013] The three-way valve can form a parallel structure between the original oil return pipeline and the newly added oil return pipeline. The lubricating oil discharged from the oil seal is switched through the three-way valve and flows into the oil return pipeline formed by the first delivery pipe or the oil return pipeline for oil return, thereby solving the problem of blockage of the oil return pipeline in the later stage or the inability to clean the channel after being blocked due to coking, and ensuring the stability of the oil return.

[0014] Preferably, the first delivery pipeline is a DN25 stainless steel pipe.

[0015] Preferably, the second delivery pipeline is a DN10 stainless steel pipe.

[0016] By increasing the pipe diameter, the oil can be naturally cooled by heat exchange with the outside air during oil return, reducing the operating time and cost of the cooling device. At the same time, it can effectively avoid blockage or obstruction.

[0017] Preferably, the oil outlet of the filter tank is provided with a check valve, one end of the second delivery pipe is detachably arranged on the check valve, and the other end is inserted through the top opening of the oil storage tank.

[0018] The two ends of the first delivery pipe are connected in a detachable manner. When the pipe diameter is found to be reduced after long-term use, the second delivery pipe can be disassembled and the inner wall can be cleaned separately, thereby restoring the second delivery pipe to a smooth state and ensuring the flow stability of the return lubricating oil.

[0019] Preferably, the cooling device is composed of a cooling coil wound in the filter tank, and the medium of the cooling coil is water or condensate.

[0020] The second purpose of this application is achieved by the following technical solution:

[0021] An online transformation method for a final polymerization kettle shaft seal lubricating oil cooling and filtering system, characterized by comprising:

[0022] S1. Install the filter tank below the shaft seal. Connect one end of the second delivery pipe to the filter tank through a check valve, and insert the other end through the opening of the oil storage tank cover. Then insert one end of the first delivery pipe into the filter tank.

[0023] S2. Take protective measures and dismantle the oil return line of the oil outlet of the shaft seal when the final polymerization kettle shaft seal is normally supplied with lubricating oil;

[0024] S3. Install the open three-way valve to the oil outlet of the shaft seal, and then insert one end of the first delivery pipe into the non-oil-discharging port on the three-way valve;

[0025] S4. Switch the three-way valve to allow the lubricating oil to flow along the first delivery pipe into the filter tank and then flow back into the oil storage tank through the second delivery pipe;

[0026] S5. Install the disassembled oil return pipeline end onto the three-way valve to realize parallel connection with the first delivery pipeline.

[0027] Preferably, the cleaning method of the second delivery pipeline includes:

[0028] A1. Switch the three-way valve to allow the lubricating oil to flow along the oil return line and close the check valve.

[0029] A2. Pull one end of the second delivery pipe from the oil tank, then remove the other end from the check valve and insert one end into the sewage channel;

[0030] A3. Aim the high-pressure steam gun at the other end of the second conveying pipe and start the steam gun for flushing. Reset the gun after flushing is completed.

[0031] Preferably, the method for cleaning the oil return pipeline includes:

[0032] B1. Switch the three-way valve to allow the lubricating oil to flow along the first delivery pipeline and open the check valve;

[0033] B2. Pull out one end of the oil return line from the oil tank, then remove the other end from the three-way valve and insert one end into the drain channel;

[0034] B3. Aim the high-pressure steam gun at the other end of the oil return line and start the steam gun for flushing. Reset the gun after flushing is completed.

[0035] Preferably, the method for replacing the lubricating oil in the oil storage barrel includes:

[0036] C1. Switch the three-way valve to allow the lubricating oil to flow along the first delivery pipeline;

[0037] C2. Open the oil change valve at the bottom to allow the lubricating oil to flow out along the oil change valve and into the waste oil barrel;

[0038] C3. Observe the liquid level in the oil storage barrel and pour in new lubricating oil when the liquid level reaches the oil outlet;

[0039] C4. Observe the lubricating oil discharged from the oil change valve until the lubricating oil is discharged and the newly added lubricating oil is closed.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The filter tank can quickly filter the sludge generated by high temperature in the first time, thereby minimizing the entry of sludge and carbon deposits into the second delivery pipeline, ensuring the long-term smooth operation of the second delivery pipeline and the existing oil supply pipeline, and effectively reducing the internal carbon deposits and sludge adhesion of the entire circulation pipeline.

[0042] A cooling device is installed in the filter tank. When the return oil temperature is too high, the high-temperature lubricating oil can be quickly reduced to 60-80°C through the cooling device, thereby preventing the lubricating oil temperature from exceeding the rated temperature. It also effectively avoids the lubricating oil from being in a high-temperature state for a long time, making the quality stability of the lubricating oil better, and less likely to form problems such as sludge and carbon deposits. The ideal operating time can be achieved during the service life of the lubricating oil, and the purpose of replacing it once a year can be truly achieved, so that the frequency of lubricating oil replacement can be effectively controlled, and the cost of lubricating oil replacement can be effectively reduced.

[0043] When manual oil replacement is performed dynamically through the online replacement method on a regular basis, the oil in operation is drained after the oil change valve below the filter tank is opened, so that the oil is no longer discharged through the oil storage tank, which can truly realize the timely and safe discharge of the oil discharged from the shaft seal, and can also add the newly added lubricating oil when the oil storage tank drops to the lowest point, thereby realizing the addition of new lubricating oil while ensuring the minimum amount of old lubricating oil to the greatest extent. After the new lubricating oil is added, the mixed lubricating oil that has flowed out from the outlet and at the bottom of the oil storage barrel will flow to the filter tank first, thereby ensuring that the content of old lubricating oil in the lubricating oil after the complete replacement is reduced to a minimum. During the complete replacement process, there will be no fluctuation in the operation of the equipment, which truly realizes scientific qualitative and quantitative replacement, reduces unnecessary waste of oil products, and more efficiently increases the oil change efficiency, so that the final polymerization kettle shaft seal can operate more efficiently and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0045] Figure 2 is a cross-sectional view of the filter tank of the present invention;

[0046] In the figure: 1. Thermometer; 2. Oil storage tank; 3. Oil pump; 4. Flow regulating valve; 5. Filter; 6. Heat exchanger; 7. Oil pipeline; 8. Second delivery pipeline; 9. Filter tank; 10. First delivery pipeline; 11. Oil return pipeline; 12. Three-way valve; 13. Shaft seal; 14. Final polymerization reactor; 15. Flow meter; 16. Needle valve; 17. Filter; 18. Cooling device; 19. Oil change valve; 20. Check valve; 21. Metal tank; 23. Sealing cover; 22. Metal support frame; 24. Hook; 25. Hanging ring; 26. Overflow hole; 27. Partition; 28. Insulation layer. DETAILED DESCRIPTION

[0047] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0048] In the description of this application, it should be understood that the terms "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They 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 direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0049] The terms "first," "second," and the like in this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0050] Example 1:

[0051] At present, the lubricating oil cooling and filtering system of the shaft seal 13 of the final polymerization kettle includes a final polymerization reactor 14, the shaft seals 13 at both ends of the final polymerization reactor 14, and an oil station for circulating lubricating oil to the shaft seals 13 at both ends. The oil station includes an oil storage tank 2, an oil pump 3, a flow regulating valve 4, a filter 5, a heat exchanger 6, an oil pipeline 7, an oil return pipeline 11, a needle valve 16, a flow meter 15 and a thermometer 1, etc. The thermometer 1 is installed on the oil storage tank 2, and a needle valve 16 and a flow meter 15 are installed on each return oil pipeline 11. Two oil pumps 3 are arranged in parallel between the oil storage tank 2 and the flow regulating valve 4, and two filters 5 are arranged in parallel between the flow regulating valve 4 and the filter 5. There is a heating coil in the oil storage tank 2. When the temperature is normal, the oil After the lubricating oil is poured into the oil storage tank 2, it is first heated to the required temperature through the internal heating coil, and then transported outward through the oil pump 3. After the flow rate is adjusted by the flow control valve 4, it enters the filter 5 for filtration. The filtered lubricating liquid enters the heat exchanger 6, and it is judged whether to cool it down depending on the situation. When the temperature is too high, it is necessary to start the cooling water for cooling. The lubricating oil is then transported to the shaft seal 13 for lubrication through two oil pipelines 7. The lubricating oil discharged through the oil outlet of the shaft seal 13 is returned to the oil storage tank 2 through the return oil pipeline 11 for re-circulation of oil supply. There are two delivery pumps and two filters 5 respectively. When one of them has a problem, the other set can be started as a backup, thereby ensuring the continuous operation of the final polymerization reactor 14. However, due to design flaws in existing gas stations, high summer temperatures can easily cause the lubricating oil to remain elevated, rapidly shortening its service life. This can also frequently lead to blockage of the needle valve 16, making it highly dangerous to unblock the needle valve 16. In some cases, the mixer in the final polymerization reactor 14 has even been blocked due to untimely lubricating oil replacement, resulting in severe losses. Furthermore, it can be difficult to completely replace the lubricating oil. Therefore, to address these issues, an online modification was performed on the existing gas station without shutting down the plant. The specific modification structure is as follows:

[0052] like Figure 1As shown, a first delivery pipe 10 is installed at the lubricating oil outlet of the existing shaft seal 13, and the other end of the first delivery pipe 10 is connected to the filter tank 9, so that the lubricating oil discharged from the outlet of the shaft seal 13 can be delivered to the filter tank 9 through the first delivery pipe 10 for filtration, thereby removing granular impurities such as sludge, and then returned to the oil storage tank 2 through the second delivery pipe 8 for circulation. Since lubricating oil produces sludge and other substances only quickly under high temperature conditions, and the temperature of the lubricating oil mainly rises rapidly during the lubrication process of the shaft seal 13, the sludge generated at high temperature can be quickly filtered through the filter tank 9 at the first time, thereby minimizing the entry of sludge and carbon deposits into the second delivery pipe 8, ensuring the long-term smooth operation of the second delivery pipe 8 and the existing oil supply pipeline, and effectively reducing the internal carbon deposits and sludge adhesion of the entire circulation pipeline. At the same time, a cooling device 18 is installed in the filter tank 9. When the return oil temperature is too high, the high-temperature lubricating oil can be quickly reduced to 60-80°C through the cooling device 18, thereby preventing the lubricating oil temperature from exceeding the rated temperature. It also effectively prevents the lubricating oil from being in a high-temperature state for a long time, making the quality stability of the lubricating oil better, and less likely to form problems such as sludge and carbon deposits. The ideal operating time can be achieved during the service life of the lubricating oil, and the purpose of changing it once a year can be truly achieved, so that the frequency of lubricating oil replacement can be effectively controlled, and the cost of lubricating oil replacement can be effectively reduced. The lubricating oil no longer passes through the original return oil pipeline 11, so there is no longer a phenomenon of needle valve 16 being blocked, and it is guaranteed that during the operation of the equipment, there will be no quality problems with the lubricating oil, which will cause the shaft seal 13 to be ineffectively lubricated for a long time, resulting in the mixer being stuck.

[0053] At the same time, when the lubricating oil is replaced dynamically by the online replacement method on a regular basis, the lubricating oil in the operation process is drained after the oil change valve 19 below the filter tank 9 is opened, so that the lubricating oil no longer passes through the oil storage tank 2. The lubricating oil discharged from the shaft seal 13 can be discharged in a timely and safe manner. At the same time, the newly added lubricating oil can be added when the oil storage tank drops to the lowest point, thereby realizing the addition of new lubricating oil while ensuring the minimum amount of old lubricating oil to the greatest extent. After the new lubricating oil is added, the mixed lubricating oil that has flowed out from the outlet and at the bottom of the oil storage barrel will flow to the filter tank 9 first, thereby ensuring that the content of old lubricating oil in the lubricating oil after the complete replacement is reduced to a minimum. During the complete replacement process, there will be no fluctuation in the operation of the equipment, which truly realizes a scientific qualitative and quantitative replacement, reduces unnecessary waste of oil products, and more efficiently increases the oil change efficiency, so that the final polymerization reactor shaft seal 13 can operate more efficiently and stably.

[0054] A further improvement is that a detachable filter screen 17 is added to the oil inlet of the filter tank 9. When the lubricating oil enters the filter tank 9, it will be filtered through the filter screen 17 to remove impurities in the lubricating oil, so that the filtered lubricating oil is in a relatively clean state. This allows it to enter the oil storage tank more easily, pass through the filter 5 below the oil storage tank for a second filtration, and finally circulate lubrication to the shaft seal 13. This can avoid the situation where the filter screen 17 in the filter tank 9 cannot be replaced and cleaned in time, resulting in unstable oil pressure, and further reduce the cleanliness of the lubricating oil contacting the pipe wall.

[0055] A further improvement is that since there is only one return oil pipeline 11 connecting the existing oil seal and the oil storage tank 2, and a needle valve 16 and a pressure gauge are also installed on the return oil pipeline, after years of use, a certain thickness of oil sludge must have adhered to the inner wall of the return oil pipeline 11, which also leads to the pressure required by the oil pump 3 becoming increasingly higher. The final polymerization kettle is in operation all year round, making the return oil pipeline 11 difficult to clean and the cleaning cost too high, which leads to occasional blockage of the needle valve 16. Therefore, in order to avoid the problem of fluidity in the newly added pipeline, and to ensure that the original return oil pipeline 11 and the newly added first delivery pipeline 10 can be connected to the oil seal outlet, a three-way valve 12 is installed on the oil seal outlet. The three-way valve 12 can ensure that the first delivery pipeline 10 and the return oil pipeline 11 are connected at the same time, so that the original return oil pipeline 11 and the newly added return oil pipeline form a parallel structure, so that the lubricating oil discharged by the oil seal can flow into the return oil pipeline formed by the first delivery pipe or the return oil pipeline 11 for oil return after being switched by the three-way valve 12, thereby effectively solving the problem of blockage in the return oil pipeline 11 in the later stage or the problem of the channel being unable to be cleaned after being blocked by coking, and ensuring the stability of the return oil. When the return oil pipeline 11 is blocked again in the later stage during operation, the needle valve 16 can be removed in a safe environment for dredging, and even the entire return oil pipeline 11 can be cleaned. When cleaning the blockage, the lubricating oil discharged from the oil seal outlet is no longer wasted, and the operating cost is lower and the safety is higher.

[0056] At the same time, since the existing return oil pipeline 11 is divided into 6 branches, and the return oil pipeline 11 is also equipped with a needle valve 16 and a pressure gauge, when the lubricating oil produces sludge or oil blocks, it is easy to cause blockage, and as time goes by, the flow allowed to pass through will become smaller and smaller. In order to avoid the situation of the return oil pipeline 11 from occurring in the newly added pipeline in the future, the diameters of the first delivery pipeline 10 and the second delivery pipeline 8 are adjusted. Among them, the first delivery pipeline 10 adopts a DN25 stainless steel pipe, which can ensure its continued normal operation without replacement, and the second delivery pipeline 8 adopts a DN10 stainless steel pipe. Only a flow meter 15 is installed on the second delivery pipe, and no needle valve 16 is installed. This can avoid the blockage of the needle valve 16 due to the reduction in pipe diameter. At the same time, by increasing the size of the pipeline, the heat dissipation efficiency is improved while the risk of blockage is reduced. When the temperature is not high, the natural heat exchange between the second delivery pipe and the air can achieve a cooling effect; and the operating cost is lower.

[0057] A further improvement is that, in order to ensure that the second delivery pipe 8 can be regularly cleaned after long-term operation, a check valve 20 is installed on the oil outlet of the filter tank 9. One end of the second delivery pipe 8 is detachably mounted on the check valve 20, while the other end is inserted through the opening on the filling cover of the oil storage tank 2. After the installation is completed, the original return oil line 11 is generally used as a backup line, while the newly added first delivery pipe 10 and subsequent parts are the new main return oil route. Because the return oil line 11 is normally in a non-working state, it can be thoroughly cleaned after being disassembled at both ends for a sufficient time, and the oil return operation will not be affected during cleaning. If the newly added return oil route is blocked at a later time, the check valve 20 can be used to close and disassemble the second delivery pipe 8, and the internal pipeline can be regularly cleaned without affecting the return oil, thereby completely solving the problem of high difficulty and high cost in cleaning the existing return oil route.

[0058] Example 2:

[0059] like Figure 2 As shown, it is further improved that the filter tank 9 includes a rectangular metal tank 21 and a sealing cover 23, and the outside of the metal tank 21 and the sealing cover 23 are wrapped with an insulation layer 28. One end of the first delivery pipe 10 is installed on the upper end side of the metal tank 21 or the top of the sealing cover 23, the second delivery pipe 8 is installed on the lower end side of the metal tank 21, and the oil change valve 19 is installed at the bottom of the filter tank 9. The cooling device 18 is composed of a cooling coil coiled in the filter tank 9. The medium of the cooling coil is water or condensate. The filter screen 17 is located at the upper end of the metal tank 21. When the lubricating oil enters the filter tank 9, it is first filtered through the filter screen 17, which can make the sludge and other granular impurities filtered more thoroughly. The filter tank 9 of this structure has a small overall volume, a large heat exchange area, and a good thermal insulation effect, and will not cause burns.

[0060] A partition 27 is provided on the inner side of the open end of the metal can 21. An inwardly protruding quadrilateral metal support rim 22 is formed between the partition 27 and the metal can 21. The filter 17 is mounted on the metal support rim 22. The lubricating oil first flows through the filter 17 for filtration before flowing downward for reflux. This makes installation of the filter 17 more convenient. The size of the metal support rim 22 can be controlled by the position of the partition 27, thereby increasing its area and making it less susceptible to complete clogging. When the filter 17 becomes clogged and the lubricating oil cannot effectively filter and penetrate, an overflow hole 26 is provided on the partition 27 to prevent the accumulation of lubricating oil and the resulting increase in pressure. The overflow hole 26 allows the lubricating oil to flow downward promptly when it is unable to pass through the holes in the filter 17, thereby preventing the lubricating oil from accumulating on the filter 17 and preventing it from returning to the filter 17.

[0061] Example 3:

[0062] A further improvement is that the bottom of the filter tank 9 adopts a downwardly protruding conical or arc-shaped structure, which can prevent the oil sludge and other substances deposited in the filter tank 9 from flowing into the oil storage tank 2 and can be discharged promptly during oil changes. At the same time, to facilitate the replacement and cleaning of the filter 17, a number of hanging rings 25 are provided at the bottom of the sealing cover 23. The hanging rings 25 are connected to the filter 17 by hooks 24. When the sealing cover 23 is opened, the filter 17 can be pulled out together with the hooks 24, thereby avoiding the problem of the filter 17 being difficult to remove and clean, and preventing the operator from being burned by steam when removing the filter 17 after opening the cover. The filter 17 adopts a basket structure, which can ensure that when the filter 17 is removed, a large amount of oil sludge will not fall into the filter tank 9.

[0063] Example 4:

[0064] An online transformation method for a lubricating oil cooling and filtering system of a final polymerization kettle shaft seal 13 comprises:

[0065] S1. Install the filter tank 9 below the shaft seal 13. Connect one end of the second delivery pipe 8 to the filter tank 9 through the check valve 20. Insert the other end of the second delivery pipe 8 through the opening of the filling cover of the oil storage tank 2. Then insert one end of the first delivery pipe 10 into the filter tank 9.

[0066] S2. Take protective measures and remove the oil return line 11 of the oil outlet of the shaft seal 13 while the final polymerization kettle shaft seal 13 is normally supplied with lubricating oil;

[0067] S3. Install the open three-way valve 12 to the oil outlet of the shaft seal 13, and then insert one end of the first delivery pipe 10 into the non-oil-discharging interface of the three-way valve 12;

[0068] S4, switch the three-way valve 12 to allow the lubricating oil to flow along the first delivery pipe 10 to the filter tank 9, and then flow back to the oil storage tank 2 through the second delivery pipe 8;

[0069] S5. Install the disassembled end of the oil return pipeline 11 onto the three-way valve 12 to realize parallel connection with the first delivery pipeline 10.

[0070] When the existing final polymerization reactor shaft seal 13 lubricating oil cooling and filtering system is modified, the newly added filter tank 9, the first delivery pipe 10 and the second delivery pipe 8 are connected first, and then a hole is opened on the filling cover of the oil storage tank 2. Then, one end of the first delivery pipe 10 can be inserted into the oil storage tank 2 for oil return. The operation is more convenient and there is no need to damage the tank body of the oil storage tank 2. After the oil return part is installed, the return oil pipeline 11 of the shaft seal 13 oil outlet can be removed under normal protective measures. The high-temperature lubricating oil is directly dripped downward and discharged. At this time, the lower end is generally placed in a bucket for oil collection to avoid environmental pollution. When installing the three-way valve 12, the three-way valve 12 is first installed on the first delivery pipe 10, and then after the first delivery pipe 10 is opened, the three-way valve 12 is inserted into the oil outlet, and finally the return oil pipeline 11 is inserted into the three-way valve 12 as a backup. The entire modification process does not require shutting down the oil circuit, thus avoiding the problem of short-term oil shortage in the shaft seal 13. It also minimizes the risk to personnel from the oil outlet during the modification process. The modified oil supply system no longer has the problem of needle valve 16 being blocked, which also facilitates subsequent maintenance. In particular, due to the presence of the oil pump 3, the return oil pipeline can also achieve oil return through the pipeline's own pressure even without a pump.

[0071] Example 5:

[0072] Based on the embodiment 4, the cleaning method of the second delivery pipe 8 is further improved to include:

[0073] A1. Switch the three-way valve 12 to allow the lubricating oil to flow along the oil return line 11 and close the check valve 20.

[0074] A2. Pull one end of the second delivery pipe 8 out of the oil tank, then remove the other end from the check valve 20 and insert one end into the sewage channel;

[0075] A3. Align the high-pressure steam gun head with the other end of the second delivery pipe 8 and start the steam gun for flushing. Reset the gun after flushing is completed.

[0076] Since the return oil pipeline will inevitably have internal scaling problems during long-term operation, it is currently basically impossible to clean it. After the new return oil pipeline is added, the return oil channel formed by the parallel return oil pipeline 11 and the first delivery pipeline 10 forms a double reflux parallel structure. When the second delivery pipeline 8 needs to be cleaned, the lubricating oil can be allowed to flow from the return oil pipeline 11 by switching the three-way valve 12. After closing the check valve 20, the two ends of the second delivery pipe can be separated from the check valve 20 and the oil storage tank 2 respectively. Then, through the company's own high-pressure pipeline, only one end of the high-pressure steam gun pipe needs to be connected to the high-pressure pipeline valve. The high-pressure steam gun head can be aimed at the other end of the second delivery pipeline 8 and the steam gun can be started to flush. After the flushing is completed, the steam gun can be reset to complete the cleaning. This effectively solves the problem of the second delivery pipeline 8 not being able to be cleaned regularly in the later stage. In order to facilitate the disassembly and removal of the two ends of the second delivery pipeline 8, the two ends can be connected by explosion-proof metal hoses, and one end of the first delivery pipeline 10 can also be connected by explosion-proof metal hoses, thereby making the installation more flexible.

[0077] Example 6:

[0078] Based on the fourth embodiment, the cleaning method of the oil return line 11 is further improved to include:

[0079] B1. Switch the three-way valve 12 to allow the lubricating oil to flow along the first delivery pipe 10 and open the check valve 20;

[0080] B2. Pull out one end of the oil return line 11 from the oil tank, then remove the other end from the three-way valve 12 and insert one end into the sewage channel;

[0081] B3. Aim the high-pressure steam gun at the other end of the oil return line 11 and start the steam gun for flushing. Reset the gun after flushing is completed.

[0082] The operating principle is basically the same as that of Example 3. After cleaning by this method, the internal cleanliness of the oil return line 11 can be effectively guaranteed, and the stability during oil return can be guaranteed.

[0083] Example 7:

[0084] Based on the fourth embodiment, the method for replacing the lubricating oil in the oil storage barrel is further improved to include:

[0085] C1. Switch the three-way valve 12 to allow the lubricating oil to flow along the first delivery pipe 10;

[0086] C2. Open the oil change valve 19 at the bottom to allow the lubricating oil to flow out along the oil change valve 19 and into the waste oil barrel;

[0087] C3. Observe the liquid level in the oil storage barrel and pour in new lubricating oil when the liquid level reaches the oil outlet;

[0088] C4. Observe the lubricating oil discharged from the oil change valve 19 until the lubricating oil is discharged and the newly added lubricating oil is closed.

[0089] When the lubricating oil needs to be replaced, the first step is for the operator to open the oil change valve 19 at the bottom of the filter tank 9, and the lubricating oil in the operation process is discharged outward through the oil change valve 19, so that the lubricating oil is no longer discharged through the oil storage tank 2; the second step is to observe the liquid level of the lubricating oil inside the oil storage tank 2. When the lubricating oil is basically drained, some new lubricating oil is slowly poured in. The poured lubricating oil can avoid the old lubricating oil in the oil storage tank 2 while ensuring normal oil supply; the third step is to wait until the newly poured mixed lubricating oil is discharged to the lowest point, and then pour in the remaining new lubricating oil; the fourth step is to observe the oil output of the oil change valve 19. When the lubricating oil discharged by the oil change valve 19 is the newly added lubricating oil, it is closed to complete the oil change operation. This effectively avoids the problem of certain fluctuations in the equipment caused by too low liquid level control when new lubricating oil is introduced into the existing equipment. The two inlet and outlet positions can effectively avoid the waste of lubricating oil. By replacing the lubricating oil by scientific qualitative and quantitative methods, the purity of the oil can be guaranteed to the greatest extent, making its service life more stable and the flow inside the conveying pipeline smoother.

[0090] The above-mentioned embodiments are only preferred embodiments of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and replacements made by technicians in this field based on the present application shall fall within the scope of protection required by the present application.

Claims

1. A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal, comprising a filter tank (9), a first delivery pipe (10) arranged between the filter tank (9) and the lubricating oil outlet of the shaft seal (13), a second delivery pipe (8) arranged between the filter tank (9) and an oil storage tank (2), a cooling device (18) arranged in the filter tank (9), and an oil change valve (19) arranged below the filter tank. Lubricating oil discharged from the shaft seal (13) enters the filter tank (9) through the first delivery pipe (10) for filtration and is then delivered to the oil storage tank (2) through the second delivery pipe (8). The high-temperature lubricating oil in the filter tank (9) can be cooled by turning on the cooling device (18). The lubricating oil in the operating state is discharged outward through the oil change valve (19), and new lubricating oil is added through the oil storage tank (2).

2. A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal according to claim 1, characterized in that: The oil seal outlet is provided with a three-way valve (12), the three-way valve (12) is connected to the first delivery pipeline (10) and the oil return pipeline (11), and the lubricating oil discharged from the oil seal flows into the first delivery pipeline (10) or the oil return pipeline (11) after being switched by the three-way valve (12).

3. A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal according to claim 2, characterized in that: The first delivery pipeline (10) is made of a DN25 stainless steel pipe; the second delivery pipeline (8) is made of a DN10 stainless steel pipe.

4. A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal according to claim 2, characterized in that: The oil outlet of the filter tank (9) is provided with a check valve (20), one end of the second delivery pipe (8) is detachably arranged on the check valve (20), and the other end is inserted through the top opening of the oil storage tank (2).

5. The cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal according to claim 1, characterized in that: The oil inlet of the filter tank (9) is provided with a detachable filter screen (17), and the lubricating oil flowing out of the first delivery pipe (10) is filtered through the filter screen (17) and then flows into the filter tank (9).

6. A cooling and filtering system for lubricating oil in a final polymerization reactor shaft seal according to claim 5, characterized in that: The cooling device (18) is composed of a cooling coil wound in the filter tank (9), and the medium of the cooling coil is water or condensate.

7. A method for online transformation of the cooling and filtering system of the shaft seal lubricating oil of a final polymerization reactor, characterized by: include: S1. Install the filter tank (9) below the shaft seal (13), connect one end of the second delivery pipe (8) to the filter tank (9) through the check valve (20), and insert the other end through the opening of the oil tank (2). Then, insert one end of the first delivery pipe (10) into the filter tank (9); S2. Take protective measures and dismantle the oil return line (11) of the oil outlet of the shaft seal (13) while the final polymerization kettle shaft seal (13) is normally supplied with lubricating oil; S3. Install the open three-way valve (12) to the oil outlet of the shaft seal (13), and then insert one end of the first delivery pipe (10) into the non-oil-discharging port on the three-way valve (12); S4, switching the three-way valve (12) to allow the lubricating oil to flow along the first delivery pipe (10) into the filter tank (9), and then flow back into the oil storage tank (2) through the second delivery pipe (8); S5. Install the disassembled end of the oil return pipeline (11) onto the three-way valve (12) to realize parallel connection with the first delivery pipeline (10).

8. The online transformation method of the final polymerization reactor shaft seal lubricating oil cooling and filtering system according to claim 7, characterized in that: The cleaning method of the second delivery pipeline (8) comprises: A1. Switch the three-way valve (12) to allow the lubricating oil to flow along the oil return line (11), and close the check valve (20); A2. Pull one end of the second delivery pipe (8) out of the oil storage tank, then remove the other end from the check valve (20) and insert one end into the sewage channel; A3. Align the high-pressure steam gun head with the other end of the second delivery pipe (8) and start the steam gun to flush. After flushing is completed, reset it.

9. The online transformation method of the final polymerization reactor shaft seal lubricating oil cooling and filtering system according to claim 7, characterized in that: The cleaning method of the oil return pipeline (11) comprises: B1. Switching the three-way valve (12) allows the lubricating oil to flow along the first delivery pipe (10), and opening the check valve (20); B2. Pull out one end of the oil return line (11) from the oil tank, then remove the other end from the three-way valve (12) and insert one end into the sewage channel; B3. Aim the high-pressure steam gun at the other end of the oil return line (11) and start the steam gun to flush. Reset the gun after flushing is completed.

10. The online transformation method of the final polymerization reactor shaft seal lubricating oil cooling and filtering system according to claim 7, characterized in that: The method for replacing the lubricating oil in the oil storage barrel includes: C1, switching the three-way valve (12) to allow the lubricating oil to flow along the first delivery pipe (10); C2. Open the oil change valve (19) at the bottom to allow the lubricating oil to flow out along the oil change valve (19) and into the waste oil barrel; C3. Observe the liquid level in the oil storage barrel and pour in new lubricating oil when the liquid level reaches the oil outlet; C4. Observe the lubricating oil discharged from the oil change valve (19) until the lubricating oil is discharged and the newly added lubricating oil is closed.

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