Catalytic cracking flue gas conveying device

Abstract

The utility model relates to the technical field of chemical engineering, and discloses a catalytic cracking flue gas conveying device which comprises a conveying pipe group used for providing catalytic cracking flue gas for external energy recovery equipment, a main body pipe connected to the conveying pipe group and a test plate arranged in the main body pipe, and the test plate is used for simulating blades of a flue gas turbine. The main body pipe is connected to the transmission pipe group so as to receive the catalytic cracking flue gas and wash the catalytic cracking flue gas onto the test plate. A part of catalytic cracking flue gas led to the energy recovery equipment from the transmission pipe group is led out of the main body pipe to serve as experimental test flue gas, so that the problem that gas-solid two-phase flowing flue gas in a flue gas turbine cannot be reduced by an existing test device is solved, and the accuracy of experimental data is improved.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, specifically to a catalytic cracking flue gas conveying device. Background Technology

[0002] Catalytic cracking is a core process in the oil refining industry. With increasing unit throughput, the volume of regenerator flue gas has exceeded 5000 Nm³. 3 The flow rate is [unclear - likely a unit of speed] / min, and the flue gas temperature is in the range of 600-700℃. To recover the energy from this high-temperature flue gas, flue gas turbines are commonly used for energy conversion, and this technology has significant economic benefits.

[0003] In industrial production, the long-term stable operation of flue gas turbines is crucial for ensuring economic benefits. However, in actual operation, it has been found that the fine catalyst powder entrained in the high-temperature flue gas continuously erodes the rotor blades, causing a scale layer to gradually form on the blade surface. When the scale accumulates to a certain extent, it will cause rotor dynamic imbalance, leading to excessive vibration and forcing the unit to shut down, seriously affecting the continuous operation of the energy recovery system.

[0004] Currently, the scaling mechanism of fine catalyst powder inside the flue gas turbine due to the variable operating conditions of catalytic cracking processes is not fully understood. Although existing simulation testing devices can partially simulate the scaling process, they cannot accurately reproduce the actual gas-solid two-phase flow state inside the flue gas turbine, leading to biased experimental results and making it difficult to provide effective guidance for actual operation. Utility Model Content

[0005] The purpose of this invention is to overcome the limitations of existing testing devices in reproducing the gas-solid two-phase flow of flue gas inside a flue gas turbine.

[0006] To achieve the above objectives, this utility model provides a conveying device for catalytic cracking flue gas, comprising a transmission pipe assembly for supplying catalytic cracking flue gas to an external energy recovery device, a main pipe connected to the transmission pipe assembly, and a test plate disposed in the main pipe. The test plate is used to simulate the blades of a flue gas turbine. The main pipe is connected to the transmission pipe assembly to receive the catalytic cracking flue gas and flush it onto the test plate.

[0007] Optionally, the device further includes a first separator and a second separator connected to the first separator, both of which are connected to the energy recovery equipment via a transmission pipe assembly;

[0008] The second separator is configured to divert catalytic cracking flue gas sub-streams from the first separator, and the main tube is configured to receive the flue gas output from the second separator.

[0009] Optionally, a nozzle is provided inside the main tube, which can accelerate the catalytic cracking flue gas flowing from the main tube onto the test plate.

[0010] Optionally, the outer circumferential surface of the nozzle is sealed to the inner circumferential surface of the main tube.

[0011] Optionally, the nozzle has an orifice with an inner diameter that decreases along the airflow direction.

[0012] Optionally, the nozzle includes a wear-resistant liner with holes.

[0013] Optionally, the nozzle includes a baffle located upstream of the wear-resistant liner and a fixed plate located downstream of the wear-resistant liner, the baffle and the fixed plate being respectively attached to the two side surfaces of the wear-resistant liner.

[0014] Optionally, a fixing ring is provided inside the main tube downstream of the wear-resistant liner, and the test plate is connected to the fixing ring.

[0015] Optionally, the main tube and the transmission tube assembly can be detachably connected.

[0016] Optionally, the main tube is provided with a pressure relief hole, a temperature measuring hole, and a pressure measuring hole.

[0017] Through the above technical solution, the main tube of this utility model uses the catalytic cracking flue gas from a portion of the transmission tube group that is diverted to the energy recovery equipment as experimental test flue gas, thereby solving the problem that existing test devices cannot reproduce the gas-solid two-phase flow flue gas in the flue gas turbine and improving the accuracy of experimental data. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the flue gas scaling simulation mechanism of this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the testing section of this utility model;

[0020] Figure 3 This is a schematic diagram of the nozzle structure of this utility model;

[0021] Figure 4 This is a schematic diagram of the test plate and fixing ring of this utility model.

[0022] Explanation of reference numerals in the attached figures

[0023] 1. First separator; 101. Ash hopper; 2. Second separator; 3. Transfer pipe assembly; 301. First flue gas pipe; 302. Second flue gas pipe; 303. Experimental pipe; 304. Control valve; 4. Main pipe; 401. Pressure relief hole; 402. Temperature measuring hole; 403. Pressure measuring hole; 404. Flange; 5. Test plate; 6. Nozzle; 601. Hole; 602. Wear-resistant liner; 603. Baffle; 604. Fixing plate; 605. Inner cylinder; 606. Liner; 7. Fixing ring; 8. Dust storage tank; 9. Critical nozzle; 10. Fixing component; 1001. Fixing bolt; 1002. Fixing nut; 11. Dust collection tank. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0025] refer to Figure 1 and Figure 2 The catalytic cracking flue gas conveying device of this utility model includes a transmission pipe group 3 for supplying catalytic cracking flue gas to an external energy recovery device, a main pipe 4 connected to the transmission pipe group 3, and a test plate 5 disposed in the main pipe 4. The test plate 5 is used to simulate the blades of a flue gas turbine. The main pipe 4 is connected to the transmission pipe group 3 to receive the catalytic cracking flue gas and flush it onto the test plate 5.

[0026] In this process, the catalytic cracking flue gas is diverted from the transmission pipe group 3 and flows onto the test plate 5 inside the main tube 4. The fine catalyst particles carried in the catalytic cracking flue gas will collide with the surface of the test plate 5, causing a rebound and adhesion process, thus forming scale.

[0027] Through the above technical solution, the main tube 4 of this utility model uses a portion of the catalytic cracking flue gas from the transmission tube group 3 that leads to the energy recovery equipment as the experimental test flue gas in the main tube 4, thereby solving the problem that the existing test device cannot reproduce the gas-solid two-phase flow flue gas in the flue gas turbine and improving the accuracy of the experimental data.

[0028] Generally, the regenerator treats the catalyst at high temperatures to promote the complete combustion of the coke on the catalyst surface. This combustion process produces catalytic cracking flue gas containing a variety of pollutants and some catalyst particles.

[0029] In this invention, the energy recovery equipment mainly includes a waste heat boiler and a flue gas turbine, used to recover energy from catalytic cracking flue gas.

[0030] In some embodiments, the apparatus may further include a first separator 1 and a second separator 2 connected to the first separator 1, both of which are connected to the energy recovery device via a transmission pipe assembly 3.

[0031] The second separator 2 is configured to divert catalytic cracking flue gas sub-stream from the first separator 1, and the main tube 4 is configured to receive the flue gas output from the second separator 2.

[0032] The transmission component includes a first flue gas pipe 301 and a second flue gas pipe 302. There are two first flue gas pipes 301, which are used to connect the first separator 1 to the waste heat boiler and the flue gas turbine, respectively. The second flue gas pipe 302 is used to connect the first separator 1 to the waste heat boiler.

[0033] The main tube 4 can be connected to the second flue gas tube 302. It is worth noting that the diameter of the main tube 4 needs to be consistent with the diameter of the second flue gas tube 302 to ensure a constant cross-sectional area for the catalytic cracking flue gas flow. Of course, in some other embodiments, the main tube 4 can also be connected to the first flue gas tube 301.

[0034] In this invention, the inlet of the first separator 1 is connected to an external regenerator to receive the catalytic cracking flue gas generated by the regenerator. The inlet of the second separator 2 is connected via a pipe to the dust outlet of the ash hopper 101 at the bottom of the first separator 1. The ash hopper 101 is used to temporarily store the catalyst particles separated by the first separator 1.

[0035] There is a pressure difference between the waste heat boiler and the first separator 1. This pressure difference can drive the catalytic cracking flue gas that moves from the inside of the first separator 1 to the dust inlet of the ash hopper 101 and enters the second separator 2.

[0036] Advantageously, the catalytic cracking flue gas sub-stream diverted by the second separator 2 accounts for only 3% to 5% of the total flow. Therefore, the diameter of the second flue gas pipe 302 is much smaller than that of the first flue gas pipe 301 to facilitate the installation of the main pipe 4.

[0037] Understandably, compared to installing the main pipe 4 on the first flue gas pipe 301, such as Figure 1 The illustrated embodiment can also reduce disturbances to the flow state of the main catalytic cracking flue gas in the first flue gas pipe 301, thereby ensuring that the flow stability and operating efficiency of the energy recovery equipment (waste heat boiler, flue gas turbine) are not affected.

[0038] In some embodiments, the bottom dust outlet of the second separator 2 is connected to a dust collection tank 11, and the outlet at the lower end of the dust collection tank 11 is connected to a dust storage tank 8. The dust collection tank 11 can be configured to discharge catalyst particles into the dust storage tank 8 when the weight of the catalyst particles stored inside reaches a predetermined threshold, and after the discharge is completed, close the connection between the dust collection tank 11 and the dust storage tank 8, so that the entire device does not need to be shut down when the dust storage tank 8 is replaced.

[0039] In this invention, the catalytic cracking flue gas diverted by the first separator 1 carries the catalyst particles from the ash hopper 101 into the second separator 2. After separation by the second separator 2, the catalyst particles enter the dust collection tank 11 through the dust outlet at the bottom of the second separator 2, and are finally stored in the dust storage tank 8.

[0040] In some embodiments, the main pipe 4 may be connected in parallel to the second flue gas pipe 302. This is intended to ensure that, when the main pipe 4 is installed, the catalytic cracking flue gas in the second separator 2 can still flow into the waste heat boiler through the second flue gas pipe 302, thus preventing excessive accumulation of catalyst particles in the ash hopper 101 in the first separator 1, which could clog its dust outlet and prevent catalytic cracking flue gas from entering the second separator 2. Simultaneously, this ensures that testing can be conducted at any time during the operation of the catalytic cracking flue gas conveying device, and that disassembling the main pipe 4 will not affect the operation of the catalytic cracking flue gas conveying device.

[0041] In some embodiments, an experimental tube 303 may be connected in parallel to the second flue pipe 302, and both ends of the main pipe 4 may be detachably connected to the experimental tube 303.

[0042] The experimental tube 303 includes a first section connected to the air inlet of the main tube 4 and the second flue gas duct, and a second section connected to the air outlet of the main tube 4 and the second flue gas duct.

[0043] Each experimental tube 303 is equipped with a control valve 304.

[0044] In some embodiments, flanges 404 are provided at both ends of the main tube 4 for detachably connecting both ends of the main tube 4 to the experimental tube 303.

[0045] Among them, the two control valves 304 are respectively installed on the two sections of the experimental tube 303.

[0046] In this invention, the first separator 1 and the second separator 2 may be equipped with heat insulation layers to prevent excessive heat loss from the catalytic cracking flue gas within the first separator 1 and the second separator 2. Simultaneously, the temperature of the catalyst particles separated by the first separator 1 is approximately close to the temperature of the catalytic cracking flue gas, resulting in virtually no heat transfer between the catalytic cracking flue gas and the carried catalyst particles within the second separator 2. This ensures that the temperatures of the catalytic cracking flue gas within the first flue gas pipe 301 and the second flue gas pipe 302 are equal or close.

[0047] In some embodiments, a nozzle 6 is provided inside the main tube 4 and located upstream of the test plate 5. The nozzle 6 can accelerate the catalytic cracking flue gas to compensate for the kinetic energy lost when the catalytic cracking flue gas sub-stream carries the catalyst particles in the ash hopper 101 of the first separator 1, so that the flow rate of the catalytic cracking flue gas in the main tube 4 is the same as or close to that of the catalytic cracking flue gas in the first nozzle, that is, the same as or close to that of the flow rate of the flue gas flowing from the first separator 1 to the flue gas turbine.

[0048] In some embodiments, a critical nozzle 9 may be provided on the second flue gas pipe 302 to accelerate the catalytic cracking flue gas sub-stream inside it, so as to avoid the waste heat boiler receiving two flue gas with different flow rates, which would cause internal disturbances in the waste heat boiler.

[0049] In this utility model, the testing process is as follows:

[0050] (1) Install the main tube 4 into the experimental tube 303;

[0051] (2) Open the two control valves 304 on the experimental tube 303 to divert the catalytic cracking flue gas to the first experimental tube 303. At this time, the diverted catalytic cracking flue gas is accelerated by the nozzle 6 and then washes the test plate 5. It then merges with the main flue gas through the second experimental tube 303 and finally flows to the waste heat boiler.

[0052] (3) Remove the main tube 4 from the experimental tube 303 and take out the test plate 5 inside the main tube 4.

[0053] In this invention, the nozzle 6 can have any suitable structure, see reference. Figure 2 and Figure 3 In one embodiment, the outer peripheral surface of the nozzle 6 is sealed to the inner peripheral surface of the main tube 4, so that the catalytic cracking flue gas in the main tube 4 is accelerated by the nozzle 6 and flows to the test plate 5.

[0054] The nozzle 6 has an orifice 601 with an inner diameter that decreases along the airflow direction, so as to gradually reduce the cross-sectional area of ​​the catalytic cracking flue gas flow and efficiently convert the flue gas pressure energy into kinetic energy, thereby accelerating the catalytic cracking flue gas.

[0055] refer to Figure 3In one embodiment, the nozzle 6 may include a wear-resistant liner 602 having a hole 601. It is understood that the wear-resistant liner 602, made of a wear-resistant material, can improve the wear resistance of the inner curved surface of the hole 601, thereby extending the service life of the wear-resistant liner 602.

[0056] It is worth noting that the wear-resistant material of the wear-resistant liner 602 must have a low coefficient of thermal expansion to prevent the internal curved surface of the hole 601 from deforming due to material expansion under high temperature conditions.

[0057] The nozzle 6 may also include a baffle 603 located upstream of the wear-resistant liner 602 and a fixing plate 604 located downstream of the wear-resistant liner 602. The baffle 603 and the fixing plate 604 are respectively attached to the two side surfaces of the wear-resistant liner 602. The baffle 603 can block the catalytic cracking flue gas from scouring the corresponding surface of the wear-resistant liner 602. Both the baffle 603 and the fixing plate 604 are fixedly connected to the main tube 4 to clamp and fix the wear-resistant liner 602 inside the main tube 4.

[0058] Both the baffle 603 and the fixing plate 604 are provided with through holes that communicate with both ends of the hole 601.

[0059] In some embodiments, the periphery of the baffle 603 and the fixing plate 604 are fixedly connected to the inner wall of the main tube 4 by circumferential welding.

[0060] In some embodiments, an inner cylinder 605 is provided between the fixing plate 604 and the main body tube 4. The outer circumferential surface of the inner cylinder 605 is fixedly connected to the inner wall surface of the main body tube 4, and a welding interface is formed between the periphery of the fixing plate 604 and the inner circumferential surface of the inner cylinder 605. When it is necessary to replace the fixing plate 604 or the wear-resistant liner 602, it can be disassembled simply by grinding the welding interface between the inner cylinder 605 and the fixing plate 604, thus avoiding damage to the main body tube 4.

[0061] The outer circumferential surface of the wear-resistant liner 602 can abut against the inner circumferential surface of the inner cylinder 605.

[0062] The windward end of the inner cylinder 605 can abut against the leeward side of the baffle 603 to provide a certain support force for the baffle 603 and improve the stability of the baffle 603 in the main tube 4.

[0063] In some embodiments, a liner 606 may be provided between the inner cylinder 605 and the fixing plate 604, which can also prevent the inner cylinder 605 from being scratched when the fixing plate 604 is replaced.

[0064] The inner cylinder 605, the liner 606, and the fixing plate 604 are all fixed using replaceable welded interfaces. (Reference) Figure 3When replacing the wear-resistant liner 602, only the weld between the liner 606 and the inner cylinder 605 needs to be ground; when replacing the fixing plate 604, only the weld between the liner 606 and the fixing plate 604 needs to be ground, thereby achieving layered maintenance, effectively reducing damage to the inner cylinder 605, and extending the service life of the inner cylinder 605.

[0065] In some embodiments, a retaining ring 7 is provided inside the main tube 4 downstream of the wear-resistant liner 602, and the test plate 5 is connected to the retaining ring 7.

[0066] In this invention, the windward surface of the test plate 5 can be attached to the leeward surface of the fixing ring 7. The catalytic cracking flue gas conveying device also includes a fixing member 10 for detachably connecting the test plate 5 to the fixing ring 7, so as to facilitate the removal of the test plate 5 from the main tube 4.

[0067] In some embodiments, reference Figure 2 and Figure 4 The fixing member 10 includes a fixing bolt 1001 that passes through the fixing ring 7 and the test plate 5. A fixing nut 1002 is screwed into the end of the fixing bolt 1001 to detachably fix the test plate 5 to the fixing ring 7. Of course, in some other embodiments, other suitable fixing methods can be used, which will not be described in detail here.

[0068] In some embodiments, the main tube 4 is also provided with a pressure relief hole 401, a temperature measuring hole 402 and a pressure measuring hole 403, all of which are located upstream of the nozzle 6 inside the main tube 4.

[0069] The temperature measuring hole 402 and the pressure measuring hole 403 are used to insert a thermometer and a pressure gauge, respectively, to measure the temperature and pressure of the catalytic cracking flue gas entering the main tube 4, thereby obtaining the temperature and pressure of the catalytic cracking flue gas.

[0070] Additionally, pressure testing port 403 is used to discharge residual catalytic cracking flue gas in the main pipe 4 through pressure relief port 401 after the test is completed and the two control valves 304 on the experimental pipeline are closed. Simultaneously, a plunger or other structure capable of blocking port 601 can be inserted into pressure relief port 401 to seal it. Both temperature testing port 402 and pressure testing port 403 can be fitted with plungers or other structures capable of blocking port 601 when not in use.

[0071] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and all fall within the protection scope of the present invention.

Claims

1. A catalytic cracking flue gas conveying device, characterized in that, It includes a transmission pipe assembly (3) for supplying catalytic cracking flue gas to an external energy recovery device, a main pipe (4) connected to the transmission pipe assembly (3), and a test plate (5) disposed in the main pipe (4). The test plate (5) is used to simulate the blades of a flue gas turbine. The main pipe (4) is connected to the transmission pipe assembly (3) to receive catalytic cracking flue gas and flush it onto the test plate (5).

2. The catalytic cracking flue gas conveying device according to claim 1, characterized in that, The device further includes a first separator (1) and a second separator (2) connected to the first separator (1), both the first separator (1) and the second separator (2) being connected to the energy recovery device through the transmission pipe group (3); The second separator (2) is configured to divert a sub-stream of catalytic cracking flue gas from the first separator (1), and the main tube (4) is configured to receive the flue gas output from the second separator (2).

3. The catalytic cracking flue gas conveying device according to claim 1, characterized in that, A nozzle (6) is provided inside the main tube (4), and the nozzle (6) can accelerate the catalytic cracking flue gas inside the main tube (4) that is flushed onto the test plate (5).

4. The catalytic cracking flue gas conveying device according to claim 3, characterized in that, The outer circumferential surface of the nozzle (6) is sealed to the inner circumferential surface of the main tube (4).

5. The catalytic cracking flue gas conveying device according to claim 3, characterized in that, The nozzle (6) has an orifice (601) whose inner diameter decreases along the airflow direction.

6. The catalytic cracking flue gas conveying device according to claim 5, characterized in that, The nozzle (6) includes a wear-resistant liner (602) on which the hole (601) is provided.

7. The catalytic cracking flue gas conveying device according to claim 6, characterized in that, The nozzle (6) includes a baffle (603) located upstream of the wear-resistant liner (602) and a fixing plate (604) located downstream of the wear-resistant liner (602), the baffle (603) and the fixing plate (604) respectively attached to the two side surfaces of the wear-resistant liner (602).

8. The catalytic cracking flue gas conveying device according to claim 7, characterized in that, A fixing ring (7) is provided inside the main tube (4) downstream of the wear-resistant liner (602), and the test plate (5) is connected to the fixing ring (7).

9. The catalytic cracking flue gas conveying device according to claim 1, characterized in that, The main tube (4) is detachably connected to the transmission tube group (3).

10. The catalytic cracking flue gas conveying device according to claim 1, characterized in that, The main tube (4) is provided with a pressure relief hole (401), a temperature measuring hole (402) and a pressure measuring hole (403).

Images