Filtering device and petrochemical enterprise hydrocarbon-containing waste gas treatment equipment and method

Abstract

The application discloses a filtering device and a petroleum chemical enterprise hydrocarbon-containing waste gas treatment equipment and method, relates to the technical field of petroleum chemical waste gas treatment, and the device shell is integrated with a pre-separation zone and a fine filtering zone. The pre-separation zone removes large particles by centrifugal force through a flow guide structure. The fine filtering zone is composed of an oil-wet coalescing filter element and an oil-avoiding separation filter element which are combined inside and outside, and is internally provided with a porous support skeleton. The device is provided with a back flushing regeneration system, the back flushing pipeline of which extends into the inside of the support skeleton, and realizes internal to external heating back flushing in combination with a heater. The application realizes long-period continuous stable operation through multi-stage gradient filtration of pre-separation and fine filtration, and on-line heating back flushing regeneration.

Description

Technical Field

[0001] This invention relates to the field of petrochemical waste gas treatment technology, specifically to a filtration device and a method for treating hydrocarbon-containing waste gas from petrochemical enterprises. Background Technology

[0002] Petrochemical enterprises generate a large amount of hydrocarbon-containing waste gas during the production process. This waste gas usually contains solid particulate matter, liquid hydrocarbon droplets, and gaseous hydrocarbon components. If it is directly discharged, it will not only waste resources but also cause serious environmental pollution. Therefore, it is necessary to purify the hydrocarbon-containing waste gas and recover the hydrocarbon components.

[0003] The existing petrochemical waste gas treatment equipment has the following shortcomings: Patent document CN121003864A discloses a gas source treatment device for an exhaust gas purging control box. "This invention discloses a gas source treatment device for an exhaust gas purging control box in the field of exhaust gas purging technology, comprising a coarse filter module for filtering solid impurities from the gas, an air compressor for pressurizing the air, and a fine filter module for filtering water and oil from the gas, connected in sequence. The fine filter module includes a tank, an inlet pipe, a drain pipe, a spiral tube disposed within the tank and coaxial with the tank, a fine filter mechanism, a drive system for driving the spiral tube and the fine filter mechanism, and an exhaust mechanism. The exhaust gas..." The air source treatment device of the purge control box, in the process of fine filtration and separation of oil mist particles in the gas, achieves the effect of high-frequency, small-amplitude, and uniform repeated compression of the elastic filter element through the expansion pipe of repeated purging and venting. This is beneficial to accelerate the aggregation of oil mist particles and the discharge of oil droplets, and can effectively improve the gas filtration effect and efficiency. However, the compression effect of the elastic filter element achieved by the expansion pipe of repeated purging and venting in the above-mentioned document has limited backflushing uniformity and stripping effect on viscous hydrocarbons, and there are technical problems that make it difficult to meet the deep regeneration of the separation filter element in the treatment of hydrocarbon-containing waste gas. Summary of the Invention

[0004] The purpose of this invention is to provide a filtration device and a method for treating hydrocarbon-containing waste gas in petrochemical enterprises, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a filtration device for treating hydrocarbon-containing waste gas in petrochemical enterprises, comprising: The casing is equipped with an air inlet, an air outlet, and a liquid outlet; The housing is further provided with a pre-separation zone and a fine filtration zone. The pre-separation zone is provided with a flow guide structure that causes the incoming exhaust gas to rotate. The fine filtration zone is provided with a coalescing filter element and a separation filter element located inside the coalescing filter element. An air inlet chamber is formed between the coalescing filter element and the inner wall of the housing. An air outlet chamber is formed inside the separation filter element and is connected to the air outlet. The drain port is located at the bottom of the housing. The coalescing filter element is made of oleophilic and hydrophobic glass fiber, and the surface contact angle of the glass fiber with hydrocarbon droplets is 15° to 30°. The separation filter element is composed of an oleophilic and hydrophobic polytetrafluoroethylene microporous membrane and a support layer. The surface contact angle of the polytetrafluoroethylene microporous membrane with hydrocarbon droplets is 130° to 155°. A porous support skeleton is provided on the inner side of the separation filter element. The backflush regeneration system includes a backflush pipeline and a control valve. The backflush pipeline leads to the air outlet chamber inside the separator filter element, and the outlet end of the backflush pipeline passes through the housing and extends into the porous support frame located in the air outlet chamber to apply a backflush airflow from the inside to the outside to the separator filter element. The air inlet end of the backflush pipeline is connected to an external air source through a connecting pipeline equipped with a heater.

[0006] Preferably, the coalescing filter element is made of oleophilic and hydrophobic glass fibers wound together, and the diameter of the glass fibers is 1μm to 10μm; The pore size of the polytetrafluoroethylene microporous membrane of the separation filter element is 0.1 μm to 1 μm; The porous support frame has uniformly distributed airflow channels inside, so that the backflush airflow passes evenly from the inside to the outside through the separation filter element; The heater is used to heat the backflush gas to 30°C to 80°C.

[0007] Preferably, the air outlet is located at the center of the top of the shell, and the air outlet chamber is connected to the air outlet through an air outlet pipe arranged along the central axis of the shell. The flow guiding structure is a spiral flow guide blade, and an annular gap is left between the inner edge of the spiral flow guide blade and the outer wall of the air outlet pipe. An electromagnetic valve is provided on the air outlet pipe. The electromagnetic valve is linked with the control valve. During backflushing regeneration, the control valve is opened and the electromagnetic valve is closed. During normal filtration, the control valve is closed and the electromagnetic valve is opened. The filtration device also includes a differential pressure detection unit for detecting the pressure difference between the air inlet chamber and the air outlet chamber. The control valve and the solenoid valve open and close in conjunction with the detection result of the differential pressure detection unit.

[0008] Preferably, an oleophobic pre-interception net is provided between the pre-separation zone and the coalescing filter element. The oleophobic pre-interception net is woven from oleophobic and hydrophobic polytetrafluoroethylene fibers and is used to intercept larger hydrocarbon droplets remaining in the gas flow after pre-separation to prevent them from directly impacting the coalescing filter element.

[0009] Preferably, the mesh size of the oleophobic pre-interceptor mesh is 50μm to 200μm.

[0010] Preferably, the incoming exhaust gas rotates under the action of the spiral guide vanes, causing large particles and droplets entrained in the exhaust gas to separate under the action of centrifugal force and flow downward along the inner wall of the shell to the drain port. The drain port is connected to a collection tank, and a liquid level control drain valve is provided on the drain path. The lower part of the shell is a conical collection section, and the drain port is located at the bottom of the conical collection section.

[0011] A hydrocarbon-containing waste gas treatment device for petrochemical enterprises includes a filtration device, a condenser, and an adsorption device as described above, connected sequentially along the waste gas flow direction. The condenser is a shell-and-tube heat exchanger used to condense and recover hydrocarbon components in the waste gas, and the adsorption device is an adsorption tank filled with activated carbon used to adsorb residual hydrocarbon substances after condensation.

[0012] A method for treating hydrocarbon-containing waste gas from a petrochemical enterprise, characterized by using the aforementioned hydrocarbon-containing waste gas treatment equipment for petrochemical enterprises, includes the following steps: S1. The hydrocarbon-containing waste gas is introduced into the filtration device, and large particles and droplets are removed by the rotary separation in the pre-separation zone. Then, the tiny droplets are agglomerated and grown by the coalescing filter element and intercepted and separated by the separation filter element. The purified gas is discharged from the outlet. S2. The purified gas is passed into the condenser for cooling, and some hydrocarbon liquids are recovered by condensation. S3. The condensed gas is introduced into the adsorption device to adsorb the residual hydrocarbons and then discharged after meeting the standards.

[0013] Preferably, the filtration device further includes an oleophobic pre-interception net. After the hydrocarbon-containing waste gas is introduced into the filtration device, the waste gas is separated by rotation in the pre-separation zone, and then the larger residual droplets are intercepted by the oleophobic pre-interception net before entering the coalescing filter element.

[0014] Preferably, the filtration device further includes a differential pressure detection unit for detecting the pressure difference between the inlet chamber and the outlet chamber. During the operation of the filtration device, when the differential pressure detected by the differential pressure detection unit exceeds a set threshold, the control valve is opened and the solenoid valve is closed. Backflush gas heated to 30°C to 80°C by a heater is introduced into the separator filter element through the backflush pipeline for backflush regeneration. The particles and droplets removed by backflush fall into the bottom of the housing and are discharged from the drain port. The operating temperature of the condenser is -10°C to 10°C.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention sets up a pre-separation zone composed of a flow guiding structure, which causes the incoming waste gas to rotate. Under the action of centrifugal force, large particles and large droplets are separated first as the first stage of treatment. At the same time, the pre-separation zone, together with the subsequent oleophobic pre-interception net, oleophilic coalescence filter element, and oleophobic separation filter element, forms a multi-stage gradient filtration system, which significantly reduces the pollutant load entering the fine filtration zone and effectively prevents filter element clogging. In addition, with the back-flushing regeneration system that is from the inside out and has a heating function, the separation filter element can be deeply cleaned without stopping the machine, thereby achieving long-term continuous and stable operation of the device. 2. This invention uses a coalescing filter element made of glass fiber with an oleophilic-hydrophobic surface modification. The glass fiber has a surface contact angle of 15° to 30° with hydrocarbon droplets. The separation filter element is composed of an oleophilic-hydrophobic polytetrafluoroethylene (PTFE) microporous membrane and a support layer. The PTFE microporous membrane has a surface contact angle of 130° to 155° with hydrocarbon droplets. The two are arranged coaxially inside and out. The exhaust gas passes through the oleophilic-hydrophobic coalescing filter element from the outside to the inside. Tiny hydrocarbon droplets are preferentially captured and coalesced on the glass fiber surface. Then, the airflow carries the grown droplets into the inner oleophilic-hydrophobic separation filter element. The droplets are intercepted on the outer surface of the separation filter element. Because the PTFE microporous membrane has oleophobic properties, the intercepted droplets will not spread on the membrane surface to form a liquid film that blocks the micropores, thus ensuring continuous and efficient gas-liquid separation. 3. This invention sets up an oleophobic pre-interception net between the pre-separation zone and the coalescing filter element. This oleophobic pre-interception net is woven from oleophobic and hydrophobic polytetrafluoroethylene fibers. It can intercept larger hydrocarbon droplets remaining in the gas flow after pre-separation, preventing them from directly impacting the coalescing filter element and further reducing the treatment load of the coalescing filter element. At the same time, due to the oleophobic properties of the oleophobic pre-interception net, the intercepted droplets are not easy to adhere and spread on its surface and are easy to drip and discharge under the action of gravity. This forms a four-stage gradient treatment path of "cyclone pre-separation → oleophobic net interception → oleophilic coalescence → oleophobic membrane fine separation". Each treatment level has a clear division of labor and progresses step by step, which significantly improves the overall removal efficiency of droplets of different particle sizes in hydrocarbon-containing waste gas. 4. This invention features a pre-separation zone constructed from a flow-guiding structure, specifically spiral guide vanes. An annular gap exists between the inner edge of the spiral guide vanes and the outer wall of the outlet pipe. This allows the incoming exhaust gas to rotate within the annular space between the inner wall of the housing and the outer wall of the outlet pipe. Under centrifugal force, large particles and droplets are separated. Simultaneously, this annular gap ensures the isolation between the exhaust gas rotation channel and the central outlet channel, preventing interference. This achieves an optimized design with a simple structure and the shortest airflow path. Furthermore, in conjunction with a backflush regeneration system, the backflush pipe leads to the outlet chamber inside the separator filter element, and the outlet end of the backflush pipe extends into the outlet chamber after passing through the housing. Inside the porous support frame, there is a solenoid valve on the air outlet pipe. During backflushing regeneration, the solenoid valve and the control valve are linked. When the control valve opens, the solenoid valve closes, preventing the backflushing gas from being discharged from the air outlet. This forces the backflushing gas to pass through the separation filter element only from the inside out. The backflushing airflow is injected from the inside out, which is the opposite of the direction of the airflow passing through the separation filter element from the outside in during normal filtration. This allows the gas to be directly blown from the clean side to the contaminated side of the filter element, efficiently blowing off particulate matter and hydrocarbon droplets adhering to the outer surface of the separation filter element. At the same time, the backflushing gas source is taken from an external gas source and heated before use. The heated backflushing gas can effectively reduce the viscosity of viscous hydrocarbon substances, making them easier to blow off. 5. This invention is equipped with a differential pressure detection unit to monitor the pressure difference between the air inlet and outlet chambers in real time, and automatically controls the linkage opening and closing of the backflush regeneration system and solenoid valve according to the differential pressure signal, so as to realize on-demand regeneration and intelligent control, which not only ensures the filtration effect, but also avoids unnecessary backflush air consumption. 6. This invention combines a filtration device, a condenser, and an adsorption device in series. The filtration device efficiently removes particulate matter and droplets at the front end, which greatly improves the cleanliness of the gas entering the condenser, effectively prevents scaling on the heat exchange tubes, and maintains long-term stable heat exchange efficiency. At the same time, after the clean gas enters the adsorption device, the pores of the activated carbon are not easily blocked, the service life of the activated carbon is significantly extended, the overall system operation cycle is greatly improved, the hydrocarbon recovery rate is high, and the emission gas consistently meets the standards. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the flow guiding structure of the present invention; Figure 4 This is a schematic diagram of the process for treating hydrocarbon-containing waste gas in petrochemical enterprises according to the present invention. Figure 5 This is a schematic diagram of the process for treating hydrocarbon-containing waste gas in petrochemical enterprises according to the present invention.

[0017] In the diagram: 1. Shell; 2. Air inlet; 3. Air outlet; 4. Drain outlet; 5. Pre-separation zone; 6. Fine filtration zone; 7. Flow guiding structure; 8. Coalescing filter element; 9. Separating filter element; 10. Air inlet chamber; 11. Air outlet chamber; 12. Backflush regeneration system; 13. Backflush pipeline; 14. Control valve; 15. Heater; 16. Differential pressure detection unit; 17. Oil-repellent pre-intercepting net; 18. Collection tank; 19. Liquid level control drain valve; 20. Condenser; 21. Adsorption device; 22. Solenoid valve. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Example 1: Please refer to Figure 1 , Figure 2 and Figure 3 The present invention provides a filtration device for treating hydrocarbon-containing waste gas in petrochemical enterprises, comprising a shell 1, a pre-separation zone 5, a fine filtration zone 6, and a backflushing regeneration system 12; The shell 1 is a vertical pressure vessel with an air inlet 2 at the top, an air outlet 3 at the top center, and a liquid outlet 4 at the bottom. The lower part of the shell 1 is a conical liquid collection section, and the liquid outlet 4 is located at the bottom of the conical liquid collection section, which facilitates the collection and centralized discharge of the separated liquid and solid particles. The pre-separation zone 5 is located in the upper part of the shell 1, downstream of the inlet 2. The pre-separation zone 5 is equipped with a flow guide structure 7, which is a spiral guide vane fixed to the inner wall of the shell 1. The outer edge of the spiral guide vane is fixed to the inner wall of the shell 1, and the inner edge extends towards the center of the shell 1, leaving an annular gap between it and the outer wall of the outlet pipe. When the hydrocarbon-containing waste gas enters the shell 1 from the inlet 2, the airflow generates a high-speed rotational motion under the guidance of the spiral guide vane. Under the action of centrifugal force, large particles and larger diameter particles entrained in the waste gas are separated. The droplets are thrown against the inner wall of the housing 1 and flow downward along the inner wall under the action of gravity, eventually collecting in the conical liquid collection section at the bottom of the housing 1 and being discharged through the drain port 4. The vent pipe is arranged along the central axis of the housing 1, and is vertically led out from the vent chamber 11 at the top of the separator filter element 9, passing through the central area of ​​the spiral guide vane and the oil-repellent pre-intercepting net 17, and communicating with the vent 3 located at the center of the top of the housing 1. The annular gap between the inner edge of the spiral guide vane and the outer wall of the vent pipe ensures the isolation between the exhaust gas rotation channel and the central vent channel, so that they do not interfere with each other. In this embodiment, the removal efficiency test conditions for particles and droplets with a diameter greater than 10 μm in the pre-separation zone 5 are as follows: under the conditions of exhaust gas flow rate of 500 Nm³ / h, liquid concentration of 5 g / m³, and median particle size of hydrocarbon droplets of 3 μm, the concentration of particles and droplets at the inlet and outlet of the pre-separation zone is measured online using a laser particle size analyzer, and the removal efficiency is calculated by the concentration difference between the inlet and outlet. After repeated tests, the average value is taken. The removal efficiency of particles and droplets with a diameter greater than 10 μm in the pre-separation zone 5 can reach more than 95%. An oleophobic pre-intercepting mesh 17 is installed below the pre-separation zone 5 and above the fine filtration zone 6. The oleophobic pre-intercepting mesh 17 is woven from oleophobic and hydrophobic polytetrafluoroethylene fibers, and its mesh size is 50μm to 200μm. Before entering the fine filtration zone 6, the exhaust gas after being treated in the pre-separation zone 5 passes through the oleophobic pre-intercepting mesh 17. The larger hydrocarbon droplets remaining in the gas flow are intercepted by the oleophobic pre-intercepting mesh 17 and drip down under the action of gravity. Since the polytetrafluoroethylene fibers have oleophobic properties, the intercepted droplets are not easy to adhere and spread on the surface of the mesh, and can drip down smoothly and be discharged, avoiding the problem of easy clogging when traditional metal wire mesh intercepts oily droplets. The center of the oleophobic pre-intercepting mesh 17 is provided with a through hole for the exhaust pipe to pass through, and the outer wall of the exhaust pipe is sealed to the through hole. After further purification by the oleophobic pre-interception net 17, the exhaust gas continues downward into the fine filtration zone 6. The fine filtration zone 6 is located below the oleophobic pre-interception net 17, in the lower middle part of the housing 1. The fine filtration zone 6 contains a coalescing filter element 8 and a separation filter element 9 located inside the coalescing filter element 8. The coalescing filter element 8 is cylindrical and composed of oleophilic and hydrophobic glass fibers wound together. The glass fibers have a surface contact angle of 15°–30° with hydrocarbon droplets, and a diameter of 1μm–10μm. The oleophilic and hydrophobic properties of the glass fibers give their surface a certain degree of oleophobicity and hydrophobicity. Due to the preferential wettability of oily substances, when tiny hydrocarbon droplets in the exhaust gas pass through the fiber layer, the droplets preferentially adhere to the fiber surface and gradually coalesce and grow as subsequent droplets are captured, evolving from tiny droplets into large droplets. The separation filter element 9 is also cylindrical, coaxially arranged inside the coalescing filter element 8, and is composed of an oleophobic and hydrophobic polytetrafluoroethylene (PTFE) microporous membrane and a support layer. The PTFE microporous membrane has a surface contact angle of 130° to 155° for hydrocarbon droplets, and the pore size of the PTFE microporous membrane is 0.1 μm to 1 μm. The PTFE microporous membrane has extremely low surface energy and exhibits oleophobicity towards hydrocarbon liquids. When agglomerated and grown droplets reach the membrane surface, they are intercepted on the outside and do not spread to form a liquid film on the membrane surface, thus maintaining the air permeability of the micropores and ensuring continuous and stable gas-liquid separation efficiency. A porous support frame is provided on the inner side of the separation filter element 9. This porous support frame is located inside the air outlet chamber 11. The porous support frame has uniformly distributed airflow channels inside, which are used to enhance the structural strength of the separation filter element 9 and ensure that the backflushing airflow can travel along the entire length of the separation filter element 9. The inner surface of the filter element 9 is evenly distributed. The top of the filter element 9 is provided with a closed end cap. The coalescing filter element 8 and the inner wall of the housing 1 form an annular air inlet chamber 10. The filter element 9 forms an air outlet chamber 11. The top of the air outlet chamber 11 is connected to the air outlet 3 located at the center of the top of the housing 1 through an air outlet pipe arranged along the central axis of the housing 1, so that the purified air entering the air outlet chamber 11 is discharged from the air outlet 3. The air outlet pipe is provided with a solenoid valve 22. During normal filtration, the solenoid valve 22 is opened and the control valve 14 is closed, and the purified air is discharged from the air outlet 3 through the air outlet pipe. The backflush regeneration system 12 includes a backflush pipeline 13 and a control valve 14. One end of the backflush pipeline 13 leads to the air outlet chamber 11 inside the separator filter element 9. Specifically, the outlet end of the backflush pipeline 13 passes through the housing 1 and extends into the porous support frame located in the air outlet chamber 11. After the backflush airflow enters the porous support frame, it can pass evenly from the inside to the outside along the entire inner surface of the separator filter element 9 through the uniformly distributed airflow channels inside, avoiding the problem of uneven regeneration caused by local airflow concentration. The other end (air inlet end) of the backflush pipeline 13 is connected to an external air source through a connecting pipeline equipped with a heater 15, thereby using the heated external air source as the backflush air source. The control valve 14 is installed on the backflush pipeline 13 to control the on / off of the backflush airflow. The solenoid valve 22 is linked to the control valve 14 for control. When backflush regeneration is required, the control valve 14 opens. When the solenoid valve 22 is closed, the external gas source is heated to 30℃~80℃ by the heater 15 and enters the outlet chamber 11 through the backflush pipe 13. After being evenly distributed by the porous support frame, the backflush gas cannot be discharged from the outlet 3 because the solenoid valve 22 is closed. It can only pass through the separation filter element 9 from the inside to the outside. The direction of this backflush airflow is opposite to the direction of the airflow from the outside to the inside of the separation filter element 9 during normal filtration. It can directly and forcefully blow from the clean side to the contaminated side of the separation filter element 9. The heated backflush gas can effectively reduce the viscosity of hydrocarbon substances adhering to the outer surface of the separation filter element 9, making it easier to blow off the viscous hydrocarbon droplets and attached particles. The pollutants after being blown off fall into the conical liquid collection section at the bottom of the shell 1 under the action of gravity and are discharged from the drain port 4. After the backflush regeneration is completed, the control valve 14 is closed and the solenoid valve 22 is opened simultaneously, and the device resumes normal filtration operation. In this embodiment, the filtration device also includes a differential pressure detection unit 16. The differential pressure detection unit 16 has a high-pressure tap and a low-pressure tap. The high-pressure tap is connected to the air inlet chamber 10, and the low-pressure tap is connected to the air outlet chamber 11. It is used to detect the pressure difference between the air inlet chamber 10 and the air outlet chamber 11 in real time. The control valve 14 and the solenoid valve 22 are both connected to the differential pressure detection unit 16 and are linked to open and close according to the differential pressure detection result. The differential pressure threshold set in the differential pressure detection unit 16 is 0.5kPa to 3kPa. When the differential pressure detected by the differential pressure detection unit 16 exceeds the set threshold, it indicates that there is a lot of dirt on the outer surface of the filter element 9 and the filtration resistance is increased. At this time, the control valve 14 is automatically opened and the solenoid valve 22 is closed synchronously to perform backflushing regeneration. When the differential pressure drops to the normal range, the control valve 14 is automatically closed and the solenoid valve 22 is opened synchronously, and the device resumes normal filtration operation. Through this automatic control method, the backflushing regeneration system 12 is only started when needed, avoiding unnecessary backflushing air consumption and realizing on-demand regeneration, energy saving and consumption reduction. In this embodiment, the drain port 4 is connected to the collection tank 18 via a pipe for collecting the separated liquid and the contaminants removed by backflushing. A level control drain valve 19 is provided on the drain path between the drain port 4 and the collection tank 18. When the liquid level in the collection tank 18 reaches the preset high liquid level, the level control drain valve 19 automatically opens to drain the liquid. When the liquid level drops to the preset low liquid level, the level control drain valve 19 automatically closes to prevent gas from leaking from the drain port 4 and ensure the safe operation of the device.

[0022] Example 2: Please refer to Figure 1 , Figure 2 and Figure 4 The present invention provides a hydrocarbon-containing waste gas treatment device for petrochemical enterprises, comprising a filter device, a condenser 20 and an adsorption device 21 connected in sequence along the waste gas flow direction; The filtration device adopts the filtration device of Example 1. The condenser 20 is a shell-and-tube heat exchanger with an operating temperature of -10℃ to 10℃. It is used to condense and liquefy the hydrocarbon components in the filtered purified gas and recover them. The adsorption device 21 is an adsorption tank filled with activated carbon. It is used to adsorb a small amount of hydrocarbon substances that remain in the gas phase after condensation, so as to ensure that the emitted gas meets the environmental protection standards. The outlet 3 of the filter device is connected to the inlet of the condenser 20 through a pipe, and the outlet of the condenser 20 is connected to the inlet of the adsorption device 21 through a pipe, thus forming a complete process flow for treating hydrocarbon-containing waste gas. In actual operation, due to the efficient removal of particulate matter and droplets by the filtration device, the cleanliness of the gas entering the condenser 20 is greatly improved, the scaling rate on the surface of the heat exchange tube is significantly reduced, and the heat exchange efficiency of the condenser 20 can be kept stable for a long time. At the same time, the gas entering the adsorption device 21 contains almost no clogging impurities, and the service life of the activated carbon is extended by more than 2 times compared with the conventional process without a pre-filtration device.

[0023] Example 3: Please refer to Figure 5 The present invention provides a method for treating hydrocarbon-containing waste gas from petrochemical enterprises, using the hydrocarbon-containing waste gas treatment equipment of Example 2, comprising the following steps: S1. The hydrocarbon-containing waste gas generated by the petrochemical enterprise is introduced into the filtration device through the air inlet 2. The waste gas first enters the pre-separation zone 5 and generates high-speed rotation under the guidance of the spiral guide vanes. Large particles of solid matter and large-diameter liquid droplets carried in the waste gas are thrown towards the inner wall of the shell 1 under the action of centrifugal force and flow downward along the inner wall, and collect in the conical liquid collection section at the bottom of the shell 1. S2. After pre-separation, the exhaust gas passes downward through the oleophobic pre-interception net 17. The large hydrocarbon droplets remaining in the gas flow are intercepted by the oleophobic pre-interception net 17. Under the action of gravity, they drip downward and collect at the bottom of the shell 1. Since the oleophobic pre-interception net 17 is woven from oleophobic and hydrophobic polytetrafluoroethylene fibers, the intercepted droplets are not easy to adhere to and block the mesh. S3. After further purification by the oleophobic pre-interception net 17, the exhaust gas enters the fine filtration zone 6. First, it passes through the coalescing filter element 8 from the outside to the inside. The oleophilic and hydrophobic glass fiber of the coalescing filter element 8 captures tiny hydrocarbon droplets in the exhaust gas. The droplets gradually coalesce and grow on the fiber surface. Then, the exhaust gas carries the coalesced and grown droplets and continues to flow inward to the separation filter element 9. The oleophobic and hydrophobic polytetrafluoroethylene microporous membrane of the separation filter element 9 intercepts the droplets on the outside of the filter element. Due to the oleophobic properties of the membrane material, the intercepted droplets will not spread on the membrane surface to form a liquid film that blocks the micropores. The clean gas enters the exhaust chamber 11 through the microporous membrane and flows upward along the central axis of the housing 1 through the exhaust pipe at the top of the exhaust chamber 11. After passing through the opened solenoid valve 22, it is finally discharged from the exhaust port 3 located at the center of the top of the housing 1, and the purified gas is obtained. The intercepted droplets drip downward under the action of gravity and collect at the bottom of the housing 1. S4. During the operation of the filtration device, the differential pressure detection unit 16 monitors the pressure difference between the inlet chamber 10 and the outlet chamber 11 in real time. When the scale buildup on the outside of the filter element 9 gradually increases and the pressure difference rises to the differential pressure threshold of 0.5 kPa to 3 kPa set in the differential pressure detection unit 16, the control valve 14 automatically opens and the solenoid valve 22 closes simultaneously, starting the backflush regeneration process. At this time, external air source gas is introduced into the heater 15 through the connecting pipeline, heated to 30℃ to 80℃, and then enters the porous support frame inside the filter element 9 through the backflush pipeline 13. The solenoid valve 22 is closed, preventing the backflushing gas from being discharged from the outlet 3. After being evenly distributed through the airflow channels in the porous support frame, the backflushing gas passes evenly from the inside to the outside through the separation filter element 9. The backflushing gas is opposite to the normal filtration airflow direction, blowing off the particulate matter and hydrocarbon droplets adhering to the outer surface of the separation filter element 9. The blown-off pollutants fall into the conical liquid collection section at the bottom of the housing 1 under the action of gravity. When the differential pressure detection unit 16 detects that the differential pressure has dropped to the normal range, the control valve 14 automatically closes and the solenoid valve 22 opens simultaneously. The backflushing regeneration ends and the filtration device resumes normal filtration operation. S5. The liquid collected in the conical liquid collection section at the bottom of the shell 1 and the pollutants removed by backflushing are discharged into the liquid collection tank 18 through the drain port 4. The liquid level control drain valve 19 automatically controls the discharge according to the liquid level in the liquid collection tank 18. When the liquid level reaches the preset high liquid level, the liquid level control drain valve 19 automatically opens to discharge the collected liquid. When the liquid level drops to the preset low liquid level, the liquid level control drain valve 19 automatically closes to prevent gas leakage. S6. The purified gas discharged from the outlet 3 of the filter device enters the condenser 20 and is cooled at an operating temperature of -10℃ to 10℃. The hydrocarbon components in the gas phase are condensed into liquid hydrocarbons and recovered. S7. The gas treated by the condenser 20 enters the adsorption device 21, where residual trace hydrocarbons are adsorbed by the activated carbon bed, and the gas is finally purified and discharged in compliance with standards.

[0024] To verify the technical effects of the various technical features of this invention, the following comparative experiments were conducted using the single variable principle. All experiments were conducted continuously under the same hydrocarbon-containing waste gas conditions (waste gas flow rate 500 Nm³ / h, liquid concentration 5 g / m³, median hydrocarbon droplet diameter 3 μm). The filtration efficiency was calculated by detecting the inlet and outlet hydrocarbon concentrations using a gas chromatograph. The pressure difference was monitored online using a differential pressure transmitter. The continuous operating cycle of the filter element was measured as the time required for the pressure difference to reach twice the initial pressure difference. Comparative Example 1: The only difference from Example 1 is that the oleophobic pre-intercepting net 17 is not provided, and the rest of the structure (including the backflush pipe 13 extending into the porous support frame, the backflush gas being heated to 30°C to 80°C, and the air outlet pipe being equipped with a solenoid valve 22) is the same as Example 1.

[0025] Comparative Example 2: The only difference from Example 1 is that the outlet end of the backflush pipe 13 does not extend into the porous support frame, but only has one outlet end in the air outlet chamber 11. The backflush airflow is directly ejected from this outlet end. The rest of the structure (including setting an oil-repellent pre-intercepting net 17, heating the backflush air to 30℃~80℃, and providing a solenoid valve 22 in the air outlet pipe) is the same as in Example 1.

[0026] Comparative Example 3: The only difference from Example 1 is that the backflush air is not heated and is backflush at room temperature. The rest of the structure (including setting up an oil-repellent pre-intercepting net 17, the backflush pipe 13 extending into the porous support frame, and the air outlet pipe being equipped with a solenoid valve 22) is the same as Example 1.

[0027] Comparative Example 4: The only difference from Example 1 is that the solenoid valve 22 is not installed on the air outlet pipe, and the rest of the structure (including the installation of the oil-repellent pre-intercepting net 17, the backflush pipe 13 extending into the porous support frame, and the backflush gas being heated to 30°C to 80°C) is the same as Example 1.

[0028] Comparative Example 5: The only difference from Example 1 is that the coalescing filter element 8 is made of ordinary glass fiber, which has a surface contact angle of more than 30° with hydrocarbon droplets. The rest of the structure (including the setting of oleophobic pre-interception net 17, the polytetrafluoroethylene microporous membrane of separation filter element 9 having a surface contact angle of 130° to 155° with hydrocarbon droplets, the backflush pipe 13 extending into the porous support frame, the backflush gas being heated to 30° to 80°, and the outlet pipe being equipped with a solenoid valve 22) is the same as that of Example 1.

[0029] Comparative Example 6: The only difference from Example 1 is that the separation filter element 9 is made of a common polytetrafluoroethylene microporous membrane, which has a surface contact angle of less than 130° for hydrocarbon droplets. The rest of the structure (including the setting of an oleophobic pre-interception net 17, the glass fiber of the coalescing filter element 8 having a surface contact angle of 15° to 30° for hydrocarbon droplets, the backflush pipe 13 extending into the porous support frame, the backflush gas being heated to 30° to 80°, and the outlet pipe being equipped with a solenoid valve 22) is the same as that of Example 1.

[0030] Comparative Example 7: The only difference from Example 1 is that there is no annular gap between the inner edge of the spiral guide vane and the outer wall of the outlet pipe, and the inner edge of the spiral guide vane is in close contact with the outer wall of the outlet pipe. The rest of the structure (including the setting of the oleophobic pre-interception net 17, the surface contact angle of the glass fiber of the coalescing filter element 8 to hydrocarbon droplets being 15° to 30°, the surface contact angle of the polytetrafluoroethylene microporous membrane of the separation filter element 9 to hydrocarbon droplets being 130° to 155°, the backflush pipe 13 extending into the porous support skeleton, the backflush gas being heated to 30° to 80°, and the outlet pipe being equipped with a solenoid valve 22) is the same as that of Example 1.

[0031] The results of the continuous operation comparison test under the same hydrocarbon-containing exhaust gas conditions are shown in Table 1: Table 1 Results of the single-variable comparative experiment Filtration efficiency ≥99.5% Approximately 89.2% Approximately 92.0% Approximately 93.3% Approximately 93.4% Approximately 88.5% Approximately 90.1% Approximately 91.8% initial pressure difference 0.5 kPa 0.6 kPa 0.5 kPa 0.5 kPa 0.5 kPa 0.5 kPa 0.5 kPa 0.5 kPa Pressure difference after 200 hours of continuous operation 0.8kPa 2.1 kPa 1.6 kPa 1.4 kPa 1.3 kPa 2.4 kPa 2.0 kPa 1.8kPa Filter element continuous operation cycle 1200h 480h 720h 600h 900h 420h 540h 660h Pressure differential recovery rate after backflushing regeneration 98% 95% 82% 72% 72% 92% 93% 85% Oil-repellent pre-blocking net cleaning cycle No separate cleaning required This part is not available. No separate cleaning required No separate cleaning required No separate cleaning required No separate cleaning required No separate cleaning required No separate cleaning required As shown in Table 1: (1) Compared with Comparative Example 1, the setting of the oleophobic pre-intercepting net 17 increases the continuous operation cycle of the filter element from 480h to 1200h, and the filtration efficiency increases from about 98.2% to ≥99.5%. Moreover, the oleophobic pre-intercepting net 17 does not need to be cleaned separately in Example 1, indicating that the oleophobic pre-intercepting net 17 effectively intercepts larger droplets, reduces the processing load of the coalescing filter element 8, and slows down the filter element clogging process. At the same time, its oleophobic properties make the intercepted droplets less likely to adhere and spread, and they are easy to drip and discharge under the action of gravity, avoiding the problem of traditional wire mesh being easily clogged and requiring frequent cleaning. (2) Comparing Example 1 and Comparative Example 2, after the backflush pipe 13 extends into the porous support frame to achieve uniform air distribution, the pressure difference recovery rate after backflush regeneration increases from 82% to 98%, and the continuous operation cycle of the filter element increases from 720h to 1200h, indicating that the uniform air distribution of the porous support frame significantly improves the cleaning effect and uniformity of backflush regeneration. (3) Compared with Comparative Example 1 and Comparative Example 3, after the backflushing gas was heated to 30℃~80℃, the pressure difference recovery rate after backflushing regeneration increased from 75% to 98%, and the continuous operation cycle of the filter element increased from 600h to 1200h, indicating that heating backflushing effectively reduced the viscosity of viscous hydrocarbons, making them easier to be blown off and peeled. (4) Compared with Comparative Example 1 and Comparative Example 4, after the solenoid valve 22 was installed in the outlet pipe, the pressure difference recovery rate after backflushing regeneration increased from 72% to 98%, and the continuous operation cycle of the filter element increased from 900h to 1200h. This shows that the solenoid valve 22 effectively prevented the backflushing gas from escaping from the outlet and ensured that all the pressure of the backflushing airflow acted on the separation filter element. (5) Compared with Comparative Example 1 and Comparative Example 5, after the coalescing filter element 8 adopts oleophilic and hydrophobic glass fiber with a surface contact angle of 15° to 30°, the filtration efficiency is increased from about 88.5% to ≥99.5%, an increase of more than 11 percentage points. The continuous operation cycle of the filter element is increased from 420h to 1200h, which is nearly twice as long. This shows that the oleophilic and hydrophobic properties of glass fiber and its specific surface contact angle range enable tiny hydrocarbon droplets to be preferentially captured and efficiently coalesced and grown on the fiber surface, which is one of the key factors for improving filtration efficiency. (6) Compared with Comparative Example 1 and Comparative Example 6, after the separation filter element 9 adopts an oleophobic and hydrophobic polytetrafluoroethylene microporous membrane with a surface contact angle of 130° to 155°, the filtration efficiency is increased from about 90.1% to ≥99.5%, an increase of more than 9 percentage points. The continuous operation cycle of the filter element is increased from 540h to 1200h, which is more than doubled. This shows that the oleophobic properties of the polytetrafluoroethylene microporous membrane and its specific surface contact angle range can effectively prevent the intercepted droplets from spreading on the membrane surface to form a liquid film, maintain the microporous permeability, and ensure continuous and efficient gas-liquid separation. (7) Comparing Example 1 and Comparative Example 7, after setting an annular gap between the inner edge of the spiral guide vane and the outer wall of the outlet pipe, the filtration efficiency increased from about 91.8% to ≥99.5%, the continuous operation cycle of the filter element increased from 660h to 1200h, and the pressure difference recovery rate after backflushing regeneration increased from 85% to 98%. This shows that the annular gap ensures the isolation between the exhaust gas rotation channel and the central outlet channel, so that they do not interfere with each other. It achieves an optimized design with a simple structure and the shortest airflow path, while ensuring the separation effect of the pre-separation zone and the cleaning effect of backflushing regeneration. The above results show that the seven technical features of this invention—oil-repellent pre-interception mesh, uniform air distribution through porous support skeleton, heated backflushing, solenoid valve linkage, contact angle of oleophilic and hydrophobic glass fiber surface, contact angle of oleophilic and hydrophobic polytetrafluoroethylene microporous membrane surface, and annular gap between spiral guide vanes and air outlet pipe—each play their respective roles in reducing filter element load, improving backflushing uniformity, enhancing dirt removal effect, ensuring backflushing pressure, optimizing material surface properties, and optimizing flow channel structure. Furthermore, the combination of these features produces a comprehensive technical effect that exceeds the sum of the effects of each individual feature.

[0032] Working principle: By setting up a pre-separation zone 5 composed of a flow guiding structure 7, the incoming waste gas is rotated. Under the action of centrifugal force, large particles and large droplets are separated first as the first stage of treatment. At the same time, the pre-separation zone 5, together with the subsequent oleophobic pre-interception net 17, oleophilic coalescing filter element 8, and oleophobic separation filter element 9, forms a multi-stage gradient filtration system, which significantly reduces the pollutant load entering the fine filtration zone 6 and effectively prevents filter element clogging. On this basis, with the help of the internally heated backflushing regeneration system 12, the separation filter element 9 can be deeply cleaned without stopping the machine. This achieves long-term continuous and stable operation of the device, solving the problem of easy clogging and frequent shutdown required when traditional filters treat viscous hydrocarbon waste gas. The coalescing filter element 8 is made of oleophilic and hydrophobic glass fiber, while the separation filter element 9 is composed of an oleophilic and hydrophobic polytetrafluoroethylene microporous membrane and a support layer, with both arranged coaxially inside and out. Exhaust gas first passes through the oleophilic and hydrophobic coalescing filter element 8 from the outside in. Tiny hydrocarbon droplets are preferentially captured and coalesced on the glass fiber surface. Subsequently, the airflow carries the grown droplets into the inner oleophilic and hydrophobic separation filter element 9, where the droplets are intercepted on the outer surface. Due to the oleophobic properties of the polytetrafluoroethylene microporous membrane, the intercepted droplets do not spread on the membrane surface to form a liquid film that blocks the micropores, thus ensuring continuous and efficient gas-liquid separation. This synergistic design of materials and structure in the "oleophilic coalescence-oleophobic separation" process achieves a filtration efficiency of up to 99%.More than 5% of the hydrocarbons are separated by an oleophobic pre-interception net 17, woven from oleophobic and hydrophobic polytetrafluoroethylene fibers, between the pre-separation zone 5 and the coalescing filter element 8. This net can intercept larger hydrocarbon droplets remaining in the pre-separated gas stream, preventing them from directly impacting the coalescing filter element 8 and further reducing its processing load. Simultaneously, due to the oleophobic properties of the net, the intercepted droplets are less likely to adhere and spread on its surface, and are easily dripped off under gravity. This forms a four-stage gradient treatment path: "cyclone pre-separation → oleophobic net interception → oleophilic coalescence → oleophobic membrane fine separation." Each treatment stage has a clear division of labor and progresses step by step, significantly improving the treatment of hydrocarbons containing... The overall removal efficiency of droplets of different sizes in hydrocarbon waste gas is achieved by setting up a backflushing regeneration system 12. The backflushing pipe 13 leads to the outlet chamber 11 inside the separator filter element 9, and the outlet end of the backflushing pipe 13 passes through the housing 1 and extends into the porous support frame located in the outlet chamber 11. A solenoid valve 22 is installed on the outlet pipe. During backflushing regeneration, the solenoid valve 22 is linked with the control valve 14. When the control valve 14 opens, the solenoid valve 22 closes, preventing the backflushing gas from being discharged from the outlet 3. This forces the backflushing gas to pass through the separator filter element 9 only from the inside to the outside. The backflushing airflow is injected from the inside to the outside, which is the opposite direction of the airflow passing through the separator filter element 9 from the outside to the inside during normal filtration. This allows the gas to flow from the clean side of the filter element to the contaminated side. Direct purging efficiently removes particulate matter and hydrocarbon droplets adhering to the outer surface of the separator filter element 9. Simultaneously, the backflushing gas source is an external gas source heated by heater 15. The heated backflushing gas effectively reduces the viscosity of viscous hydrocarbons, making them easier to remove. Comparative tests show that this "reverse pulse + heating" online regeneration method achieves a backflushing regeneration efficiency of over 98%. The continuous operating cycle of the filter element is extended by more than four times compared to conventional forward ambient temperature backflushing filters. The pressure difference recovery rate after backflushing regeneration is 38 percentage points higher, truly achieving uninterrupted online deep regeneration. A pressure difference detection unit 16 monitors the inlet chamber 10 and outlet chamber 11 in real time. The pressure difference between the components is used to automatically control the backflush regeneration system 12 and the solenoid valve 22, achieving on-demand regeneration and intelligent control. This ensures filtration efficiency while avoiding unnecessary backflush gas consumption. By connecting the filter, condenser 20, and adsorption device 21 in series, the filter efficiently removes particulate matter and droplets at the front end, significantly improving the cleanliness of the gas entering the condenser 20. This effectively prevents scaling on the heat exchange tubes and maintains long-term stable heat exchange efficiency. Simultaneously, after the clean gas enters the adsorption device 21, the activated carbon pores are less prone to clogging, significantly extending the activated carbon's lifespan. This greatly improves the overall system's operating cycle, resulting in high hydrocarbon recovery rates and stable compliance with emission standards.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A filtration device for treating hydrocarbon-containing waste gas in petrochemical enterprises, characterized in that, include: The shell (1) is provided with an air inlet (2), an air outlet (3) and a liquid outlet (4); The housing (1) is further provided with a pre-separation zone (5) and a fine filtration zone (6). The pre-separation zone (5) is provided with a flow guide structure (7) that causes the incoming exhaust gas to rotate. The fine filtration zone (6) is provided with a coalescing filter element (8) and a separation filter element (9) located inside the coalescing filter element (8). An air inlet chamber (10) is formed between the coalescing filter element (8) and the inner wall of the housing (1). An air outlet chamber (11) is formed inside the separation filter element (9), and the air outlet chamber (11) is connected to the air outlet (3). The drain port (4) is located at the bottom of the housing (1). The coalescing filter element (8) is made of oleophilic and hydrophobic glass fiber, and the surface contact angle of the glass fiber to hydrocarbon droplets is 15° to 30°. The separation filter element (9) is composed of an oleophilic and hydrophobic polytetrafluoroethylene microporous membrane and a support layer. The surface contact angle of the polytetrafluoroethylene microporous membrane to hydrocarbon droplets is 130° to 155°. The inner side of the separation filter element (9) is provided with a porous support skeleton. The backflush regeneration system (12) includes a backflush pipeline (13) and a control valve (14). The backflush pipeline (13) leads to the air outlet chamber (11) inside the separator filter element (9), and the outlet end of the backflush pipeline (13) passes through the housing (1) and extends into the porous support frame located in the air outlet chamber (11) to apply a backflush airflow from the inside to the outside to the separator filter element (9). The air inlet end of the backflush pipeline (13) is connected to an external air source through a connecting pipeline equipped with a heater (15).

2. The filtration device according to claim 1, characterized in that: The coalescing filter element (8) is made of oleophilic and hydrophobic glass fibers wound together, with the diameter of the glass fibers being 1μm to 10μm. The pore size of the polytetrafluoroethylene microporous membrane of the separation filter element (9) is 0.1 μm to 1 μm; The porous support frame has uniformly distributed airflow channels inside, so that the backflush airflow passes evenly from the inside to the outside through the separation filter element (9). The heater (15) is used to heat the backflush gas to 30°C to 80°C.

3. The filtration device according to claim 1, characterized in that: The air outlet (3) is located at the top center of the shell (1). The air outlet chamber (11) is connected to the air outlet (3) through an air outlet pipe arranged along the central axis of the shell (1). The flow guiding structure (7) is a spiral flow guiding blade. An annular gap is left between the inner edge of the spiral flow guiding blade and the outer wall of the air outlet pipe. An electromagnetic valve (22) is provided on the air outlet pipe. The electromagnetic valve (22) is linked with the control valve (14). During backflushing regeneration, the control valve (14) is opened and the electromagnetic valve (22) is closed. During normal filtration, the control valve (14) is closed and the electromagnetic valve (22) is opened. The filter device also includes a differential pressure detection unit (16) for detecting the differential pressure between the air inlet chamber (10) and the air outlet chamber (11). The control valve (14) and the solenoid valve (22) open and close in conjunction with the detection result of the differential pressure detection unit (16).

4. A filtration device according to claim 1, characterized in that: An oleophobic pre-intercepting net (17) is also provided between the pre-separation zone (5) and the coalescing filter element (8). The oleophobic pre-intercepting net (17) is woven from oleophobic and hydrophobic polytetrafluoroethylene fibers and is used to intercept larger hydrocarbon droplets remaining in the gas flow after pre-separation to prevent direct impact on the coalescing filter element (8).

5. A filtration device according to claim 4, characterized in that: The mesh size of the oleophobic pre-interception net (17) is 50μm to 200μm.

6. A filtration device according to claim 3, characterized in that: The incoming exhaust gas rotates under the action of the spiral guide vanes, causing large particles and droplets entrained in the exhaust gas to separate under the action of centrifugal force and flow down along the inner wall of the shell (1) to the drain port (4). The drain port (4) is connected to the collection tank (18), and a liquid level control drain valve (19) is provided on the drain path. The lower part of the shell (1) is a conical collection section, and the drain port (4) is located at the bottom of the conical collection section.

7. A hydrocarbon-containing waste gas treatment device for petrochemical enterprises, characterized in that: The device includes a filter, a condenser (20), and an adsorption device (21) connected in sequence along the direction of exhaust gas flow. The condenser (20) is a shell-and-tube heat exchanger used to condense and recover hydrocarbon components in the exhaust gas. The adsorption device (21) is an adsorption tank filled with activated carbon used to adsorb hydrocarbon substances remaining after condensation.

8. A method for treating hydrocarbon-containing waste gas from a petrochemical enterprise, characterized in that, Using the above-mentioned hydrocarbon-containing waste gas treatment equipment for petrochemical enterprises includes the following steps: S1. The hydrocarbon-containing waste gas is introduced into the filtration device, and large particles and droplets are removed by the rotational separation in the pre-separation zone (5). Then, the tiny droplets are agglomerated and grown by the coalescence filter element (8), and intercepted and separated by the separation filter element (9). The purified gas is discharged from the outlet (3). S2. The purified gas is introduced into the condenser (20) for cooling, and some hydrocarbon liquid is recovered by condensation; S3. The condensed gas is introduced into the adsorption device (21) to adsorb the residual hydrocarbons and then discharged after meeting the standards.

9. A method for treating hydrocarbon-containing waste gas from a petrochemical enterprise according to claim 8, characterized in that: The filtration device also includes an oleophobic pre-intercepting net (17). After the hydrocarbon-containing waste gas is introduced into the filtration device, the waste gas is separated by rotation in the pre-separation zone (5), and then the larger residual droplets are intercepted by the oleophobic pre-intercepting net (17) before entering the coalescing filter element (8).

10. A method for treating hydrocarbon-containing waste gas from a petrochemical enterprise according to claim 8, characterized in that: The filter device also includes a differential pressure detection unit (16) for detecting the pressure difference between the inlet chamber (10) and the outlet chamber (11). During the operation of the filter device, when the differential pressure detected by the differential pressure detection unit (16) exceeds the set threshold, the control valve (14) is opened and the solenoid valve (22) is closed. Backflush gas heated to 30°C to 80°C by the heater (15) is introduced into the separator filter element (9) through the backflush pipeline (13) for backflush regeneration. The particles and droplets removed by backflush fall into the bottom of the housing (1) and are discharged from the drain port (4). The operating temperature of the condenser (20) is -10°C to 10°C.

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