A continuous device for reprocessing blowdown tower sludge

Abstract

This application discloses a continuous waste oil recycling device for a venting tower. The device includes a quench system and a coking tower top oil / gas line. The output of the quench system is connected to the coking tower top oil / gas line and then to the venting tower inlet. A spray device is installed inside the venting tower. The oil-throwing pipeline and the quenching oil pipeline are mixed and then output to the venting tower. A reboiler is located at the bottom of the venting tower. Medium-pressure steam is connected to the reboiler shell-side inlet, and the reboiler shell-side outlet is connected to the steam condensate pipeline system. The output of the reboiler tube-side is connected to the oil-throwing pipeline and the quenching oil pipeline. This application achieves a continuous rather than intermittent operation mode, avoiding the problems of bottom pump cavitation and top reflux interruption caused by temperature fluctuations. It achieves continuous and stable operation of the venting tower, and without increasing the number of reaction towers, it not only achieves zero external waste oil discharge from the coking unit but also meets the external waste oil recycling requirements, greatly improving oil yield and reducing environmental pressure.

Description

Technical Field

[0001] This application relates to the field of sludge reprocessing technology, specifically to a venting tower sludge reprocessing device. Background Technology

[0002] Traditional delayed coking units employ intermittent venting systems. Their primary function is to process the high-temperature steam generated during the large-volume blowing and water supply phases of the coke tower during the cooling process using closed-loop in-tower contact cooling technology, and to recover some of the oil and gas carried by this steam. During the coking process and the decoking process after cooling, the venting system is idle, causing the internal temperature of the venting tower to gradually decrease. When the coke tower re-enters the cooling process, a large amount of high-temperature steam suddenly enters the venting tower, causing the condensate accumulated at the bottom to boil rapidly. This results in cavitation of the bottom pump and interruption of the top reflux, affecting the stable operation of the venting tower.

[0003] The large amount of oily waste and coke powder entrained in the high-temperature steam can easily cause coking and blockage when entering the air cooler at the top of the tower, reducing cooling efficiency. At the same time, due to the poor cooling effect of the air cooler, the amount of coke powder in the oily wastewater in the three-phase separator increases, and the emulsification is severe, making it difficult to separate effectively. This results in the oily wastewater and wastewater exceeding the standards, making it impossible to send directly to downstream treatment units and increasing environmental pressure.

[0004] Due to the poor cooling effect of the air cooler at the top of the tower, the temperature of the three-phase separator is too high. Some water vapor fails to condense completely and is discharged into the low-pressure fuel gas system along with the oil and gas. This not only affects the safety of the system, but may also pose a potential safety hazard to the fuel system.

[0005] The large amount of heat energy brought by the high-temperature steam increases the heat load of the venting tower, making it difficult to precisely control the tower top temperature. Excessively high tower top temperatures can cause heavy components that should condense and descend to evaporate to the top of the tower and enter the air cooler, where they adhere to the tube walls to form coke, further reducing heat exchange efficiency and potentially causing blockage of the air cooler. Summary of the Invention

[0006] The technical problem to be solved by this application is to overcome the existing defects and provide a continuous sludge reprocessing device for venting towers, which can effectively solve the problems in the background art.

[0007] To achieve the above objectives, this application provides the following technical solution: a continuous recycling device for sludge oil in a venting tower, comprising a quench system and a coking tower top oil and gas line, wherein the output end of the quench system is connected to the coking tower top oil and gas line and to the feed inlet of the venting tower, and a spraying device is provided inside the venting tower.

[0008] The oil slinger and quench oil pipelines are mixed and then output to the vent tower. The output end of the medium-pressure steam system is connected to the shell-side inlet of the reboiler, and the shell-side outlet of the reboiler is connected to the steam condensate pipeline system.

[0009] The tube-side outlet of the reboiler is connected to the oil slinger line and the quench oil line;

[0010] The output end of the venting tower is connected to an air cooler, the output end of the air cooler is connected to a three-phase separator, the gas phase output end of the three-phase separator is connected to a low-pressure fuel gas system, the wastewater outlet of the three-phase separator is output to an acid water outlet device through an acid water pump, and the sludge oil outlet of the three-phase separator is connected to the external sludge oil pipeline through a sludge oil pump and then connected to the sludge oil return inlet of the venting tower.

[0011] The heavy residue oil at the bottom of the venting tower is divided into three paths after being pumped through the bottom of the tower: one path returns to the bottom of the venting tower, another path connects to the tube side inlet of the reboiler, and the third path flows through the cooling water tank and is then divided into two paths: one path is sent to the top of the venting tower for reflux, and the other path is sent to the fractionation tower.

[0012] As a preferred technical solution of this application, a first automatic flow regulation loop is provided between the medium-pressure steam system and the reboiler. The first automatic flow regulation loop consists of a first flow transmitter, a first flow indicator regulator, and a first flow regulating valve group. A first temperature transmitter and a first temperature indicator regulator are provided at the bottom of the vent tower. The first temperature transmitter and the first temperature indicator regulator, together with the aforementioned first automatic flow regulation loop, form a cascade temperature regulation system at the bottom of the vent tower. The first temperature indicator regulator is used to receive signals from the first temperature transmitter and transmits the signals to the first flow indicator regulator. The output signal of the first flow indicator regulator controls the opening and closing action of the first flow regulating valve group.

[0013] As a preferred technical solution of this application, a fourth temperature transmitter and a fourth temperature indicator regulator are provided at the top of the venting tower.

[0014] As a preferred technical solution of this application, it also includes an external sludge pipeline. Before the external sludge pipeline enters the venting tower, a second automatic flow regulation system is installed. The automatic regulation system consists of a second flow transmitter, a second flow indicator regulator, and a second flow regulating valve group. A second temperature indicator is installed at the sludge return inlet of the venting tower. The second flow indicator regulator receives signals from the second flow transmitter.

[0015] As a preferred technical solution of this application, the pipeline between the distillation tower and the cooling water tank, which transports water to the top of the venting tower, is equipped with a third automatic flow regulation system. This regulation system consists of a third flow transmitter, a third flow indicator regulator, and a third flow regulating valve group. A third temperature indicator is provided at the reflux inlet at the top of the venting tower.

[0016] Compared with existing technologies, this application achieves a continuous rather than intermittent operation mode, avoiding the problems of bottom pump cavitation and top reflux interruption caused by temperature fluctuations. This enables continuous and stable operation of the venting tower, achieving zero external discharge of waste oil from the coking unit and meeting the external waste oil requirements of the refining system without increasing the number of reaction towers. This significantly improves oil yield and reduces environmental pressure. The automatic spray flow regulation device optimizes the heat exchange and washing effects inside the venting tower, effectively reducing the pollution and blockage of air coolers and other critical equipment caused by high-temperature steam carrying heavy component waste oil and coke powder, extending equipment lifespan, and reducing maintenance costs. The three-phase separator employs more effective cooling and separation technologies, reducing emulsification and thus lowering the water content of the waste oil. The system eliminates the risk of excessive oil content in wastewater, allowing treated acidic water to be smoothly sent to downstream units for refining and processing without external discharge. This reduces environmental pressure and potential fines or remediation costs associated with illegal discharges. Improved cooling efficiency ensures complete condensation of water vapor, preventing uncondensed water vapor from being discharged into the low-pressure fuel gas system along with oil and gas, thus eliminating safety hazards to the fuel system and improving overall process safety. The installation of a fourth temperature transmitter and a fourth temperature indicator controller allows for more precise control of the tower top temperature, preventing excessively high temperatures from causing heavy components to evaporate to the top of the tower and adhere to the air cooler tube walls, forming coke. This not only improves heat exchange efficiency but also prevents air cooler blockage, further ensuring the long-term efficient operation of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this application.

[0018] In the diagram: 1. Quenching system; 2. Coke tower top oil and gas line; 3. Oil slinger line; 4. Quenching oil line; 5. Medium-pressure steam system; 6. Steam condensate system; 7. Fourth temperature indicator and controller; 8. Third flow indicator and controller; 9. First flow transmitter; 10. First flow indicator and controller; 11. Acidic water pump; 12. First flow regulating valve group; 13. Reboiler; 14. First temperature transmitter; 15. First temperature indicator and controller; 16. Acidic water outlet device; 17. External sludge oil line; 18. Sludge oil pump; 19. To fractionation tower; 20. Vent tower; 21. Air cooler; 22. Fourth temperature transmitter; 23. Third temperature indicator; 24. Third flow regulating valve group; 25. Three-phase separator; 26. Third flow transmitter; 27. Second flow indicator and controller; 28. Second flow transmitter; 29. ​​Low-pressure fuel gas system; 30. Second flow regulating valve group; 31. Second temperature indicator; 32. Cooling water tank; 33. Tower bottom pump. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Please see Figure 1 This application provides a technical solution: a continuous recycling device for sludge oil in a venting tower, including a quench system 1 and a coke tower top oil and gas line 2. The output end of the quench system 1 is connected to the feed inlet of the venting tower 20 after being connected to the coke tower top oil and gas line 2. A spraying device is installed inside the venting tower 20.

[0021] The quench system 1 injects acidic water into the oil and gas line 2 at the top of the coke tower. The acidic water pre-cools the high-temperature oil and gas entering the vent tower 20, thereby reducing the heat load on the vent tower 20. This makes it easier to control the temperature at the top of the tower within the ideal range, reduces the risk of high-temperature steam carrying heavy component sludge into the air cooler 21, effectively reduces the risk of coking and blockage in the air cooler 21, extends the service life of the equipment, and reduces maintenance costs.

[0022] As a liquid distributor inside the venting tower 20, the spray device atomizes the liquid to make the distribution of liquid in the cross section of the venting tower 20 more uniform. It also increases the gas-liquid contact area and improves mass transfer efficiency. At the same time, the sprayed droplets enhance the washing effect on coke powder particles, reduce the pollution and blockage of coke powder on the air cooler 21 and other key equipment, extend the service life of the equipment, and reduce maintenance costs.

[0023] The reboiler 13 serves as an external heater for the venting tower 20, used to heat the heavy residue oil extracted from the bottom of the venting tower 20, thereby controlling the temperature at the bottom of the tower within a certain range, reducing the accumulation of water at the bottom of the tower, and preventing the bottom of the tower from being vented. The bottom pump 33 sends a portion of the heavy residue oil to the reboiler 13 for heating. The heated heavy residue oil is then fed into the oil slinger line 3 and the quench oil line 4 and sent to the lower part of the venting tower 20. The heat source for the reboiler 13 is drawn from the medium-pressure steam system 5, and the condensate from the reboiler 13 is sent back to the steam condensate system 6.

[0024] The output end of the venting tower 20 is connected to the air cooler 21, the output end of the air cooler 21 is connected to the three-phase separator 25, the gas phase output of the three-phase separator 25 is connected to the low-pressure fuel gas system 29, the sewage outlet of the three-phase separator 25 is output to the acid water outlet device 16 through the acid water pump 11, and the sludge oil outlet of the three-phase separator 25 is connected to the external sludge oil pipeline 17 through the sludge oil pump 18 and then connected to the sludge oil return inlet of the venting tower 20.

[0025] The gas exiting from the venting tower 20 enters the air cooler 21 for cooling. The air cooler 21 promotes efficiency improvement in the subsequent separation process by lowering the temperature.

[0026] After being cooled by the air cooler 21, the material enters the three-phase separator 25, where it is divided into three parts according to its physical properties: gas phase, liquid phase (oil phase) and water phase, thus achieving the purpose of resource recovery and environmental protection.

[0027] The low-pressure fuel gas system 29 receives a portion of the gaseous products from the three-phase separator 25. These gases can be used as low-quality fuels to improve energy efficiency.

[0028] The acid water pump 11 is responsible for transporting the acid water separated in the three-phase separator 25 to the downstream unit for further processing.

[0029] The heavy residue oil at the bottom of the venting tower 20 is divided into three paths after passing through the bottom pump 33: one path returns to the bottom of the venting tower 20, another path connects to the tube inlet of the reboiler 13, and the third path flows through the cooling water tank 32 and then splits into two paths: one path is sent to the top of the venting tower 20 for reflux, and the other path is sent to the fractionation tower 19.

[0030] The external waste oil pipeline 17 is used to send waste oil from outside the unit into the venting tower 20 for processing and refining, ensuring that all waste oil entering the system can be fully treated, improving oil yield and reducing environmental pollution.

[0031] Furthermore, the vent tower 20 is equipped with a cascade control system for the bottom temperature and the steam flow rate entering the reboiler 13 to achieve precise, rapid, and automatic regulation of the bottom temperature of the vent tower 20. This cascade control system consists of a first temperature transmitter 14, a first temperature indicating controller 15, and a first automatic flow control loop. The first automatic flow control loop includes a first flow transmitter 9, a first flow indicating controller 10, and a first flow control valve group 12. The first temperature indicating controller 15 acts as the main controller, receiving signals from the first temperature transmitter 14. Its output signal serves as the setpoint signal for the secondary controller—the first flow indicating controller 10. The output signal of the secondary controller—the first flow indicating controller 10—controls the opening and closing action of the first flow control valve group 12. These transmitters, indicating controllers, and control valve groups form two closed-loop control loops, namely the main and secondary ones, thereby achieving precise, rapid, and automatic regulation of the bottom temperature of the vent tower 20.

[0032] Furthermore, a fourth temperature transmitter 22 and a fourth temperature indicator regulator 7 are provided at the top of the venting tower 20 to automatically monitor and regulate the temperature of the gas phase product at the top of the venting tower 20.

[0033] Furthermore, it also includes an external sludge pipeline 17. The external sludge pipeline 17 and the venting tower 20 are equipped with a second automatic flow regulation system. This automatic regulation system consists of a second flow transmitter 28, a second flow indicator regulator 27, and a second flow regulating valve group 30. The second flow indicator regulator 27 receives signals from the second flow transmitter 28, and its output signal controls the opening and closing of the second flow regulating valve group 30, thereby realizing automatic control of the instantaneous flow rate of sludge entering the venting tower 20, ensuring the accuracy and stability of material input. The sludge inlet of the venting tower 20 is equipped with a second temperature indicator 31 to monitor the temperature of the sludge entering the venting tower 20 in real time.

[0034] Furthermore, a third automatic flow control system is installed in the section of heavy residue oil extracted from the bottom of the vent tower 20 that flows back to the top of the fractionation tower 19 via the cooling water tank 32. This system consists of a third flow transmitter 26, a third flow indicator regulator 8, and a third flow control valve group 24. The third flow indicator regulator 8 receives signals from the third flow transmitter 26, and its output signal controls the opening and closing of the third flow control valve group 24, thereby automatically controlling the amount of reflux spray at the top of the vent tower 20. A third temperature indicator 23 is installed at the reflux inlet at the top of the vent tower to monitor the reflux temperature of the vent tower 20 in real time.

[0035] In use: By adjusting the instantaneous flow rate of acidic water injection in the quench system 1, the temperature of the exhaust gas from the top oil and gas line 2 of the coke tower (i.e., the feed line of the vent tower) before entering the vent tower 20 is controlled within a certain range, thereby reducing the heat load of the vent tower 20, making the top temperature of the tower easier to control, avoiding evacuation at the bottom of the tower, and ensuring the continuous and stable operation of the vent tower 20.

[0036] The third flow indicator regulator 8 keeps the top return flow rate constant at all times;

[0037] During normal operation of the venting tower 20, the fourth temperature indicator regulator 7 is prioritized to maintain the tower top temperature at 140°C, the first temperature indicator regulator 15 at 160°C, the fifth temperature indicator regulator 17 monitors the feed temperature at 260°C, and the second flow indicator regulator 27 controls the flow rate of recycled sludge.

[0038] When the venting tower 20 is idle, the fourth flow regulating valve group 19 is closed to stop injecting acidic water into the feed line of the venting tower 20, controlling the temperature at the top of the tower to 135℃-145℃, the first temperature indicator regulator 15 at the bottom of the tower to 150℃, and controlling the flow rate of recycled sludge through the second flow indicator regulator 27.

[0039] The material processed by the venting tower 20 is cooled by the air cooler 21 and then enters the three-phase separator 25. In the three-phase separator 25, the material is separated into three parts according to its physical properties: gas phase, liquid phase (oil phase) and water phase. The gas phase is output and connected to the low-pressure fuel gas system 29. The wastewater outlet of the three-phase separator 25 is output to the acid water outlet device 16 through the acid water pump 11. The sludge oil outlet of the three-phase separator 25 is connected to the external sludge oil pipeline 17 through the sludge oil pump 18 and then connected to the sludge oil return inlet of the venting tower 20. Its flow rate is precisely controlled by the second flow regulating valve group 30. The bottom pump 33 sends a part of the product from the bottom of the venting tower 20 back into the venting tower 20 to achieve internal circulation and optimize the separation effect. The other part is cooled by the cooling water tank 32 and then sent to the fractionation tower 19 for more refined separation.

[0040] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous waste oil recycling device for a venting tower, characterized in that: It includes a quench system (1) and a coke tower top oil and gas line (2). The output end of the quench system (1) is connected to the coke tower top oil and gas line (2) and connected to the feed inlet of the vent tower (20). The vent tower (20) is equipped with a spray device. After the oil slinger (3) and the quench oil line (4) are mixed, they are output to the vent tower (20). The output end of the medium-pressure steam system (5) is connected to the shell-side inlet of the reboiler (13), and the shell-side outlet of the reboiler (13) is connected to the steam condensate pipe system (6). The output end of the tube side of the reboiler (13) is connected to the oil sling line (3) and the quench oil line (4). The output end of the venting tower (20) is connected to the air cooler (21), the output end of the air cooler (21) is connected to the three-phase separator (25), the gas phase output end of the three-phase separator (25) is connected to the low-pressure fuel gas system (29), the sludge outlet of the three-phase separator (25) is connected to the recycle sludge inlet of the venting tower (20) after being connected to the external sludge pipeline (17) through the sludge pump (18), and the wastewater outlet of the three-phase separator (25) is output to the acid water outlet device (16) through the acid water pump (11). The heavy residue oil at the bottom of the venting tower (20) is divided into three paths after passing through the bottom pump (33). One path returns to the bottom of the venting tower (20), another path is connected to the tube inlet of the reboiler (13), and the third path flows through the cooling water tank (32) and then splits into two paths. One path is sent to the top of the venting tower (20) for reflux, and the other path is sent to the fractionation tower (19).

2. The venting tower sludge oil continuous recycling device according to claim 1, characterized in that: A first flow rate automatic regulation loop is provided between the medium-pressure steam system (5) and the reboiler (13). The first flow rate automatic regulation loop consists of a first flow rate transmitter (9), a first flow rate indicator regulator (10), and a first flow rate regulating valve group (12). A first temperature transmitter (14) and a first temperature indicator regulator (15) are provided at the bottom of the vent tower (20). The first temperature transmitter (14) and the first temperature indicator regulator (15) together with the above-mentioned first flow rate automatic regulation loop form a cascade regulation system for the bottom temperature of the vent tower.

3. The venting tower sludge oil continuous recycling device according to claim 1, characterized in that: The top of the venting tower (20) is equipped with a fourth temperature transmitter (22) and a fourth temperature indicator regulator (7).

4. The venting tower sludge oil continuous recycling device according to claim 1, characterized in that: It also includes an external waste oil pipeline (17), which is equipped with a second automatic flow regulation system. The automatic regulation system consists of a second flow transmitter (28), a second flow indicator regulator (27), and a second flow regulation valve group (30). The waste oil return inlet of the empty tower (20) is equipped with a second temperature indicator (31).

5. The venting tower sludge oil continuous recycling device according to claim 1, characterized in that: The pipeline between the distillation tower (19) and the cooling water tank (32) and the top of the vent tower (20) is equipped with a third automatic flow regulation system, which consists of a third flow transmitter (26), a third flow indicator regulator (8) and a third flow regulating valve group (24). A third temperature indicator (23) is provided at the reflux inlet at the top of the vent tower (20).

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