Mechanism and method for online recovery of operation fault of valve plate of slide valve of catalytic cracking device

Abstract

The invention discloses a mechanism and a method for online recovery of an operation fault of a sliding valve plate of a catalytic cracking device. The mechanism comprises a bracket, the propelling assembly is installed at one end of the support, and a valve plate displacement driving piece is arranged in the propelling assembly; the reverse blowing assembly is mounted at the other end of the bracket and is used for conveying steam into the sliding valve of the catalytic cracking device; and when the propelling assembly rotates, the end part of the valve plate displacement driving piece penetrates through the reverse blowing assembly and extends into the catalytic cracking device to drive the valve plate to displace. Under the condition that normal production of the sliding valve is not stopped, the mechanism enables the screw valve plate displacement driving part to penetrate through the reverse blowing assembly to be inserted into the sliding valve through the propelling assembly, the valve plate in the sliding valve is driven to move, and therefore opening or closing of the valve plate is achieved, the faulted sliding valve is recovered, and the control capacity of the valve plate in the sliding valve to flow of a catalyst is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic cracking devices, and in particular relates to a mechanism and a method for online recovery of a sliding valve plate operating failure of a catalytic cracking device. Background Art

[0002] The slide valve is a key control valve on the catalyst circulation pipeline between the regenerator and the settler of the petrochemical catalytic cracking unit. In normal operation, it is used to adjust the circulation amount of the catalyst between the regenerator and the settler, and to adjust and control the reaction temperature, production capacity, product distribution, etc. of the unit. When the unit is started, shut down or an accident occurs, it is used to quickly cut off the catalyst circulation and the connection between the two devices to stop the catalyst circulation.

[0003] The slide valve is used in a harsh environment, and it works in an environment with frequent high and low temperature changes, high load and high wear for a long time. The fluid medium controlled by the slide valve is a 20-80um granular catalyst with an aluminum oxide skeleton, and the working temperature is 650°~730°. The catalyst passing through the slide valve per hour is about 700 tons to 900 tons, and the slide valve diameter is usually 800mm~1200mm (small and medium catalytic cracking units).

[0004] like Figure 4 and Figure 5 As shown, the slide valve plate 7 and the transmission valve stem 9 are connected with a T-slot, that is, a T-slot is machined on the connecting end of the valve plate 7, and a T-slot is machined at the connecting head of the valve stem 9, and the T-slot of the valve stem 9 is embedded in the T-slot of the valve plate 7 to form a structural connection; when the slide valve is working, the temperature of the catalyst flowing through the reduced diameter of the valve body is about 650° to 730°, the opening of the valve plate 7 is generally adjusted at about 30%-70%, and the temperature of the valve plate 7 changes with the opening size. When the opening is small, the temperature of the front part of the valve plate 7 can reach about 650° to 730°, and the temperature of the rear part is about 600° because it is not in direct contact with the high-temperature catalyst. The anti-clogging backblowing steam of the valve stem 9 is far away from the T-slot, and the temperature drop is not obvious. The temperature of the T-slot of the connecting part of the valve stem 9 is about 600°. When the slide valve is opened to more than 50%, the temperature of the front of the valve plate 7 is about 650°~730°, and most of the rear parts of the valve plate 7 are in the dead zone catalyst. The valve body dissipates heat, the valve stem 9 conducts heat, and the valve stem anti-clogging back-blowing steam is used for short-distance cooling, so that the temperature at the T-head of the valve stem 9 drops significantly to about 240°.

[0005] As the opening of the slide valve is adjusted, the temperature at the T-head of the valve stem 9 frequently changes between high and low temperatures, causing stress fatigue and breakage. After the connecting T-head of the valve stem 9 breaks, the valve plate and the valve stem break 19. After the electro-hydraulic actuator pushes the valve stem 9, the valve stem 9 can move against the valve plate 7 to close the valve plate 7, but when it needs to be opened, the valve plate 7 cannot be pulled, and the ability to control the catalyst is lost, so that the slide valve of the catalytic cracking unit cannot operate normally.

[0006] The failure of the valve stem 9 inside the slide valve to break or fall off is common in refining enterprises. In recent years, the inventor has participated in the maintenance and learned that there have been 5 such failures in 4 catalytic cracking units. There are about 190 catalytic cracking units in operation in China. When the valve plate 7 and valve stem 9 inside the slide valve are repaired, the slide valve needs to be shut down for at least 48 hours, and it takes at least 96 hours to restart the slide valve after repair and reach a stable production state. The shutdown period will not only lead to the loss of enterprise production capacity and product structure imbalance, but also cause great energy consumption and economic losses (the energy and material consumption of a medium-sized catalytic cracking unit is about 7 million yuan when it is shut down and started). Summary of the invention

[0007] The present invention provides a mechanism and method for online recovery of operating failure of a sliding valve plate of a catalytic cracking unit, which is used to solve the technical defect in the prior art that after the connection between the valve stem and the valve plate inside the sliding valve is broken, it is impossible to online restore the valve drive displacement inside the sliding valve to achieve opening or closing of the valve plate to control the flow of catalyst in the sliding valve.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, a mechanism for online recovery of a sliding valve plate operating failure in a catalytic cracking unit is provided, comprising:

[0010] Bracket;

[0011] A propulsion assembly is installed at one end of the bracket, and a valve plate displacement driving member is provided in the propulsion assembly;

[0012] A backflush assembly, mounted at the other end of the bracket, for delivering steam into the slide valve of the catalytic cracking unit;

[0013] Wherein, when the propulsion assembly rotates, the end of the valve plate displacement driving member passes through the backflush assembly and extends into the sliding valve of the catalytic cracking unit to drive the valve plate to move.

[0014] Further, the propulsion assembly includes a rotating propulsion wheel and a connecting rod installed on one side of the rotating propulsion wheel, and an end of the connecting rod is connected to an end of the bracket;

[0015] The back-blowing assembly comprises a sealing stuffing box and a back-blowing steam ring, one end of the sealing stuffing box is connected to the back-blowing steam ring, and the other end is connected to the bracket and is located inside the bracket, the back-blowing steam ring is connected to the other end of the bracket, and the back-blowing steam ring axially overlaps with the bracket and the sealing stuffing box;

[0016] The end of the valve plate displacement driving member sequentially passes through the sealing stuffing box and the back-blowing steam ring and extends outward;

[0017] Among them, when the rotating propulsion wheel drives the end of the valve plate displacement driving member to pass through the sealing stuffing box and the back-blowing steam ring in sequence to extend into the sliding valve of the catalytic cracking unit, the sealing stuffing box is used to seal the sliding valve of the catalytic cracking unit, and the back-blowing steam ring is used to transport back-blowing steam into the sliding valve of the catalytic cracking unit.

[0018] Furthermore, the diameter of the valve plate displacement driving member is 38 mm.

[0019] Furthermore, the valve plate displacement driving member is a spiral push rod.

[0020] Furthermore, the rotating propulsion wheel is a hand wheel.

[0021] Furthermore, the bracket is a frame-type structure.

[0022] In a second aspect, a method for online recovery of a sliding valve plate operating failure in a catalytic cracking unit is provided, the method being performed using the mechanism as described above, comprising:

[0023] Pre-open an activity hole on the slide valve;

[0024] In the opened movable hole, a hole is drilled in the wear-resistant layer inside the slide valve by using a drill bit;

[0025] Installing a high-temperature gate valve on the movable hole, and connecting the backflush assembly to the high-temperature gate valve;

[0026] By using the propulsion assembly, the valve plate displacement driving member is passed through the back-blowing assembly and the high-temperature gate valve in sequence, and extended to the interior of the slide valve to drive the valve plate to move.

[0027] Furthermore, before the movable hole is pre-opened on the slide valve, the method further includes:

[0028] Use tools such as hanging wire and horizontal pipe to determine the opening point of the slide valve housing;

[0029] Welding a flat welding flange at the determined center point of the opening of the slide valve housing;

[0030] Installing a high-temperature gate valve on the welded flat-weld flange;

[0031] Use a pressure tapping machine to cut open the outer shell of the sliding valve body.

[0032] Furthermore, the pressure tapping machine is equipped with a high temperature resistant hollow drill bit.

[0033] Furthermore, a high temperature resistant alloy grinding drill is used to drill a hole in the wear-resistant layer inside the slide valve.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The mechanism includes a bracket, a propulsion assembly and a back-blowing assembly, which are installed at both ends of the bracket. When the connection between the valve plate and the valve stem inside the sliding valve is broken, a hole is opened on the outer side of the sliding valve without stopping the normal production of the sliding valve, and the screwed valve plate displacement driving member is inserted into the sliding valve through the back-blowing assembly through the propulsion assembly to drive the valve plate inside the sliding valve to move, thereby realizing the opening or closing of the valve plate, restoring the faulty sliding valve, and realizing the control ability of the valve plate inside the sliding valve on the flow of the catalyst, solving the technical defect of the prior art that the sliding plate inside the sliding valve cannot be driven to move online without stopping the machine, and providing safety guarantee for production.

[0036] 2. By rotating the propulsion wheel to drive the valve plate displacement driving member to move, the moving distance of the valve plate displacement driving member can be accurately controlled.

[0037] 3. The diameter of the valve plate displacement drive is 38mm316L material screw. In the process of driving the valve plate displacement, it has sufficient driving strength and heat resistance and will not affect the catalyst flow area inside the sliding valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A schematic cross-sectional view of a mechanism for online recovery of a sliding valve plate operating failure in a catalytic cracking unit provided by the present invention;

[0040] Figure 2 It is a schematic diagram of the opening of the slide valve housing;

[0041] Figure 3 A schematic diagram of the operation of a mechanism for online recovery of a sliding valve plate operating failure in a catalytic cracking unit provided by the present invention;

[0042] Figure 4 It is a schematic diagram of the slide valve structure in the prior art;

[0043] Figure 5 It is a partial enlarged view of the connection between the valve plate and the valve stem inside the sliding valve in the prior art;

[0044] Figure 6 The present invention provides a flow chart of a method for online recovery of a sliding valve plate operating failure in a catalytic cracking unit;

[0045] Among them: 1. Sliding valve outer shell; 2. Inner reduced diameter shell; 3. Inner wall wear-resistant layer; 4. Valve body insulation layer; 5. Inner reduced diameter flow channel; 6. Valve plate slideway; 7. Valve plate; 8. Valve plate and valve stem connector; 9. Valve stem; 10. Electro-hydraulic actuator connecting flange; 11. Backblowing steam; 12. Rotating propulsion wheel; 13. Bracket; 14. Valve plate displacement drive; 15. Sealing stuffing box; 16. High-temperature gate valve; 17. Movable hole; 18. The break between the valve plate and the valve stem; 19. Catalyst flow channel. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0050] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0051] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] like Figure 4 and Figure 5 As shown, the slide valve of the prior art includes a slide valve outer shell 1, which is a carbon steel shell. An inner reduced diameter shell 2 is arranged inside the slide valve outer shell 1. An inner wall wear-resistant layer 3 and a valve body heat insulation layer 4 are arranged inside the inner reduced diameter shell 2. The inner wall wear-resistant heat insulation layer 3 is cast by 80mm tortoise shell mesh corundum; an inner reduced diameter flow channel 5 is arranged in the inner reduced diameter shell 2, and a valve plate slideway 6 is arranged below the inner reduced diameter flow channel 5. A valve plate 7 is slidably connected in the valve plate slideway 6. The function of the valve plate 7 is to block or divert the catalyst in the inner reduced diameter flow channel 5. The valve plate 7 is opened on the side of the valve plate 7 away from the inner reduced diameter flow channel 5. A T-shaped female groove is provided, in which a valve plate and valve stem connecting piece 8 is connected, and a valve stem 9 is connected to the end of the valve plate and valve stem connecting piece 8, and the outside of the valve stem 9 is externally connected to an electro-hydraulic actuator connecting flange 10, and the valve stem 9 is driven by the electro-hydraulic actuator to realize the displacement of the valve plate 7; back-blowing steam 11 is also provided on the sliding valve outer shell 1, and when the valve plate and valve stem connecting piece 8 is broken, the electro-hydraulic actuator cannot drive the valve plate and valve stem breaking point 18 to make the valve plate 7 displaced in the valve plate slide 6, thereby blocking or diverting the catalyst in the valve plate slide 6, causing the sliding valve to malfunction and affecting normal production.

[0053] In order to solve the above technical defects, the inventor provides a mechanism and method for online recovery of operating failure of a sliding valve plate of a catalytic cracking unit.

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0055] like Figure 1 As shown, in the first aspect of the embodiment of the present invention, there is provided a mechanism for online recovery of the operation failure of the valve plate of the sliding valve of the catalytic cracking unit, comprising a bracket 13; a propulsion assembly, mounted at one end of the bracket 13, a valve plate displacement driving member 14 is arranged in the propulsion assembly, and the propulsion assembly is used to push the valve plate displacement driving member 14 to perform reciprocating linear motion; a backflush assembly, mounted at the other end of the bracket 13, and used to deliver steam into the sliding valve of the catalytic cracking unit and seal the sliding valve of the catalytic cracking unit. When the valve plate 7 and the valve stem connecting member 8 inside the sliding valve are broken, as shown in FIG. Figure 2As shown, a movable hole 17 is opened on the outer body 1 of the sliding valve, and the movable hole 17 is axially overlapped with the valve plate 7 and the valve stem connecting member 8 and is on the same horizontal line. Then, the mechanism is erected by using the bracket 13, and the valve plate displacement driving member 14 is axially overlapped with the movable hole 17 and the valve plate and valve stem connecting member 8 and is at the same height; Figure 3 As shown, the push assembly is manually rotated, so that the end of the valve plate displacement driver 14 in the push assembly slowly passes through the backflush assembly and the movable hole 17, and is inserted into the interior of the catalytic cracking unit slide valve, contacts one end of the valve plate 7, and rests against the end of the valve plate 7, driving the valve plate 7 so that the valve plate 7 can be displaced left and right on the valve plate slideway 6, thereby restoring the valve plate 7 to control the flow of the catalyst in the inner reduced diameter flow channel 5 and the catalyst flow channel 19, and realizing the repair of the normal operation of the valve plate 7 in the slide valve without stopping the production of the catalytic cracking unit slide valve. Figure 1As shown, the propulsion assembly includes a rotating propulsion wheel 12 and a connecting rod installed on one side of the rotating propulsion wheel 12. There are multiple connecting rods, and the multiple connecting members are arranged circumferentially with a distance between each other. The ends of the multiple connecting rods are connected to the end of the bracket 13. The connection here can be welded or connected by bolts, but is not limited to this; the backflush assembly includes a backflush steam ring and a sealing stuffing box 15. The backflush steam ring is connected to the other end of the bracket 13. One end of the sealing stuffing box 15 is connected to the backflush steam ring, and the other end extends into the bracket 13 and is connected to the bracket 13. The backflush steam ring is connected to the bracket 13. The frame 13 and the sealing stuffing box 15 overlap axially; the end of the valve plate displacement driver 14 sequentially passes through the sealing stuffing box 15 and the back-blowing steam ring to extend outward; wherein, when the rotating propulsion wheel 12 rotates and drives the end of the valve plate displacement driver 14 to sequentially pass through the sealing stuffing box 15 and the back-blowing steam ring to extend into the slide valve of the catalytic cracking unit, the sealing stuffing box 15 is used to seal the movable hole 17 of the slide valve of the catalytic cracking unit, and the back-blowing steam ring is used to transport back-blowing steam into the slide valve of the catalytic cracking unit to prevent the catalyst from forming a vortex between the opening and the valve stem 9 to flush the heat-resistant lining inside the slide valve. In the process of driving the valve plate displacement driver 14 by the rotating propulsion wheel 12, the valve plate displacement driver 14 can smoothly pass through the sealing stuffing box 15 and push the valve plate 7 in the slide valve of the catalytic cracking unit, thereby realizing the valve plate 7 to control the flow of the catalyst. Among them, the valve plate displacement driving member 14 is preferably a spiral push rod, and the diameter of the valve plate displacement driving member 14 is 38 mm. In the process of driving the valve plate 7 to move, the screw has sufficient pushing strength and heat resistance, and will not affect the catalyst flow area inside the sliding valve of the catalytic cracking unit; in addition, in this embodiment, the rotating propulsion wheel 12 is preferably a hand wheel, and the valve plate displacement driving member 14 is driven by the rotation of the rotating propulsion wheel 12, which improves the convenience of operation and improves the working efficiency; finally, the bracket 13 is preferably a frame-type structure, and the operator can observe the pushing length of the valve plate displacement driving member 14 through the bracket 13 during the process of pushing the valve plate displacement driving member 14.

[0056] In a second aspect, this embodiment provides a method for online recovery of a catalytic cracking unit slide valve plate operation failure, the method being performed using the mechanism described above, such as Figure 6 As shown, including:

[0057] S101. Open an active hole on the slide valve in advance; for example, set up a temporary construction platform for the pressure hole opening machine and a propulsion mechanism operating platform, and then lay the propulsion mechanism backflush and protection steam pipeline; contact the control room of the catalytic production device to maintain the current production status, and do not open or close the slide valve. Firefighters and safety supervisors are deployed on site and carry walkie-talkies that can communicate with the control room. If the device has abnormal fluctuations, contact the on-site construction personnel to evacuate in time. Secondly, use tools such as hanging lines and horizontal pipes to determine the opening point of the sliding valve shell, weld the DN50 flat welding flange at the center point of the determined opening point of the sliding valve shell, install the DN50 high-temperature gate valve 16 on the welded flat welding flange, and install the pressurized hole opening machine on the DN50 high-temperature gate valve 16; open the DN50 high-temperature gate valve 16, connect nitrogen from the protective nitrogen port of the pressurized hole opening machine, and conduct tightness and leakage tests on the connection between the hole opening machine and the valve, and the weld between the valve and the sliding valve shell 1. The nitrogen pressure for tightness and leakage tests is set to 0.5MPa; finally, use the pressurized hole opening machine and a high-temperature resistant hollow drill bit to cut the carbon steel shell of the sliding valve body at a speed of 500 rpm, and hook out the cut sliding valve shell material.

[0058] S102. In the opened movable hole, a drill is used to drill a hole in the wear-resistant layer inside the sliding valve; illustratively, the pressure drilling machine is replaced with a high-temperature resistant alloy grinding drill bit, and the drilling machine uses backblowing protective nitrogen, and the nitrogen pressure is set to 0.3MPa. At a speed of 200 rpm, holes are drilled in the sliding valve outer shell 1, the inner wall wear-resistant layer 3 and the valve body insulation layer 4 in turn; specifically, the wear-resistant layer 3 of the inner wall of the sliding valve is ground and drilled, and the surface of the sliding valve outer shell 1 is set to the drill bit forward tool amount 0 position, and the drill bit advances 220mm as the drilling end position; start the pressure drilling machine, and observe the advance amount of the drilling machine grinding drill bit in time. When the advance position of the grinding drill bit exceeds about 200mm, the protective nitrogen pressure drops suddenly, which can be regarded as the inner wall wear-resistant layer 3 has been opened. Continue to advance the drilling machine to allow the grinding drill bit to reach 220mm to ensure that the hole is completely unobstructed. After the inner wall wear-resistant layer 3 is opened, withdraw the pressure drilling machine drill bit.

[0059] S103, installing a high-temperature gate valve on the movable hole, and connecting the back-blowing assembly to the high-temperature gate valve; illustratively, installing a high-temperature gate valve 16 on the movable hole, connecting the back-blowing assembly to the high-temperature gate valve 16, and then connecting the back-blowing assembly to the back-blowing steam 11 pipeline.

[0060] S104. Use the propulsion assembly to pass the valve plate displacement drive member through the backflush assembly and the high-temperature gate valve in sequence, and extend it to the inside of the sliding valve to drive the valve plate to move; illustratively, after the valve stem 9 and the valve plate 7 are broken, the valve plate 7 can be moved to the left and closed by the electro-hydraulic actuator, but cannot be pulled to the right. When the sliding valve is operating normally, the valve plate 7 partially blocks the inner reduced diameter flow channel 5; if the flow of the catalyst in the inner reduced diameter flow channel 5 is normally controlled, the propulsion assembly is manually rotated to rotate the end of the valve plate displacement drive member 14 so that the end of the valve plate displacement drive member 14 is slowly inserted into the interior of the sliding valve of the catalytic cracking unit through the backflush assembly and the movable hole 17, and the valve plate 7 inside the sliding valve is driven so that the valve plate 7 can be displaced left and right on the valve plate slide 6, thereby restoring the valve plate 7's control over the flow of the catalyst in the inner reduced diameter flow channel 5.

[0061] In summary, this method can be widely used in water supply, heat supply, oil and gas pipelines where the working pressure does not exceed 16Mpa and the valve plate operation control operation of the gate valve with a diameter greater than 15mm after the valve stem falls off, and normal operation can be achieved without stopping the medium transportation state.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A mechanism for online recovery of a sliding valve plate operating failure in a catalytic cracking unit, characterized in that: include: Bracket (13); A propulsion assembly is mounted on one end of the bracket (13), wherein a valve plate displacement driving member (14) is provided in the propulsion assembly; A backflush assembly, mounted on the other end of the bracket (13), for conveying steam into the slide valve of the catalytic cracking unit; When the propulsion assembly rotates, the end of the valve plate displacement driving member (14) passes through the backflush assembly and extends into the slide valve of the catalytic cracking unit, driving the valve plate (7) to move.

2. The mechanism according to claim 1, characterized in that: The propulsion assembly comprises a rotating propulsion wheel (12) and a connecting rod installed on one side of the rotating propulsion wheel (12), and an end of the connecting rod is connected to an end of a bracket (13); The back-blowing assembly comprises a sealing stuffing box (15) and a back-blowing steam ring, one end of the sealing stuffing box (15) is connected to the back-blowing steam ring, and the other end is connected to the bracket (13) and is located inside the bracket (13), the back-blowing steam ring is connected to the other end of the bracket (13), and the back-blowing steam ring axially overlaps with the bracket (13) and the sealing stuffing box (15); The end of the valve plate displacement driving member (14) sequentially passes through the sealing stuffing box (15) and the back-blowing steam ring and extends outward; When the rotating propulsion wheel (12) rotates and drives the end of the valve plate displacement driving member (14) to sequentially pass through the sealing stuffing box (15) and the back-blowing steam ring to extend into the slide valve of the catalytic cracking unit, the sealing stuffing box (15) is used to seal the slide valve of the catalytic cracking unit, and the back-blowing steam ring is used to transport back-blowing steam into the slide valve of the catalytic cracking unit.

3. The mechanism according to claim 1 or 2, characterized in that: The diameter of the valve plate displacement driving member (14) is 38 mm.

4. The mechanism according to claim 3, characterized in that: The valve plate displacement driving member (14) is a spiral push rod.

5. The mechanism according to claim 2, characterized in that: The rotating propulsion wheel (12) is a hand wheel.

6. The mechanism according to claim 1, characterized in that: The support (13) is a frame-type structure.

7. A method for online recovery of a sliding valve plate operating failure in a catalytic cracking unit, characterized in that: The method is carried out using the mechanism described in any one of claims 1 to 9, comprising: Pre-open an activity hole on the slide valve; In the opened movable hole, a hole is drilled in the wear-resistant layer inside the slide valve by using a drill bit; Installing a high-temperature gate valve on the movable hole, and connecting the backflush assembly to the high-temperature gate valve; By utilizing the propulsion assembly, the valve plate displacement driving member is passed through the back-blowing assembly and the high-temperature gate valve in sequence, and extended to the interior of the slide valve to drive the valve plate to move.

8. The method according to claim 7, characterized in that Before pre-opening the movable hole on the slide valve, it also includes: Use tools such as hanging wire and horizontal pipe to determine the opening point of the slide valve housing; Welding a flat welding flange at the determined center point of the opening of the slide valve housing; Installing a high-temperature gate valve on the welded flat-weld flange; Use a pressure tapping machine to cut open the outer shell of the sliding valve body.

9. The method according to claim 8, characterized in that The pressure tapping machine is equipped with a high temperature resistant hollow drill bit.

10. The method according to claim 7, characterized in that A high temperature resistant alloy grinding drill is used to drill a hole in the wear-resistant layer inside the slide valve.

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