Catalytic cracking cold wall slide valve packing leakage repair device

Abstract

A device for repairing leakage in a catalytic cracking cold wall slide valve packing includes an external packing box and a rear pressure cap. The external packing box is an integral structure with a packing cavity on its inner wall. The rear pressure cap is detachably connected to the external packing box. When the external packing box is installed with the cold wall slide valve device, one end of the external packing box is detachably connected to the rear end of the original packing box, and the other end of the external packing box engages with a transmission housing partition. The valve stem of the cold wall slide valve passes through the interior of the external packing box. This device can be installed immediately on-site, is simple to install, and requires no open flame, improving operational safety. After installation, it can operate safely for a long period, significantly reducing the possibility of huge losses due to the inability to quickly repair leaks.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cold-wall slide valve of heavy oil catalytic device, and particularly relates to a cold-wall slide valve packing leakage repairing device for catalytic cracking. BACKGROUND

[0002] The 1.8*10 6 The 1.8*10

[0003] In the running process, once the valve rod packing of the cold-wall slide valve fails and leaks, in order to ensure safety and control loss, it needs to be handled as soon as possible. There are two common handling methods: ① device shutdown, replacement of packing, but this way of handling generally takes a long time, resulting in huge losses. ② without shutdown, that is, welding a spare packing box at the rear end of the original packing box. Specifically, a thick mixture of molybdenum disulfide and graphite is injected into the injection port of the original packing box, and an outer protective sleeve is welded at the rear end of the original packing box. However, this way of handling also has many difficulties: in the actual operation site, the installation operation is complex, the space for installation and welding is small, and the high-temperature smoke gas mixed with catalyst leaks, which is a high-risk environment for hot work; in addition, during welding, the outer protective sleeve and the equipment body are prone to large deformation, resulting in a large deviation of the coaxiality between the outer protective sleeve and the actuator of the equipment body (even up to millimeters), which causes great damage to the equipment body and cannot meet the long-period use requirement of the equipment, and the whole equipment still needs to be replaced in the later period, so this way only delays the shutdown time. SUMMARY

[0004] In order to ensure long-period operation of the device and reduce company losses, the present application provides an external packing box to solve the risk caused by slide valve leakage, improves the packing pressing method, and eliminates hidden troubles. The present application provides a cold-wall slide valve packing leakage repairing device for catalytic cracking, and the technical scheme is as follows:

[0005] The cold-wall slide valve packing leakage repairing device for catalytic cracking comprises an external packing box and a rear gland. The external packing box is of an integrated structure, and a packing cavity is arranged in the internal part of the external packing box. The rear gland is detachably connected with the external packing box. When the external packing box is installed with the cold-wall slide valve device, one end of the external packing box is detachably connected with the rear end of the original packing box, the other end of the external packing box is matched with the partition plate of the transmission box body, and the valve rod of the cold-wall slide valve is arranged in the internal part of the external packing box.

[0006] Optionally, the outer packing box comprises a front end, a middle part and a tail end arranged in sequence, the central axis of the front end of the outer packing box, the central axis of the tail end of the outer packing box and the central axis of the middle part of the outer packing box coincide, the diameter of the front end of the outer packing box and the diameter of the tail end of the outer packing box are both smaller than the diameter of the middle part of the outer packing box; when the outer packing box is detachably connected with the rear end of the original packing box, the front end of the outer packing box is correspondingly inserted into the interior of the rear end of the original packing box.

[0007] Optionally, an annular positioning plate which is integrally formed with the front end and outwardly protrudes is fixedly sleeved on the outer wall of the front end of the outer packing box, the central axis of the annular positioning plate coincides with the central axis of the front end of the outer packing box, a plurality of positioning holes are arranged on the plate surface of the annular positioning plate and are arranged in an annular array with the central axis of the annular positioning plate as the center; when the outer packing box is detachably connected with the rear end of the original packing box, the plate surface of the annular positioning plate abuts against the rear end of the original packing box, the positioning holes and the holes arranged on the rear end of the original packing box one-to-one correspond and communicate, and are fixed by bolts.

[0008] Optionally, a sealing packing ring and a standby packing ring are arranged on the inner wall of the outer packing box, the sealing packing ring and the standby packing ring are both cavity structures to which packing is added, and a packing spacing ring for playing a partitioning role is arranged between the sealing packing ring and the standby packing ring.

[0009] Optionally, the sealing packing ring, the packing spacing ring and the standby packing ring are arranged in sequence to form a stepped series connection structure on the inner wall of the outer packing box.

[0010] Optionally, the static friction force of the packing is smaller than the valve rod thrust of the cold-wall slide valve.

[0011] Optionally, a plurality of first threaded holes are arranged on the tail end of the outer packing box, the rear gland comprises a connecting part and a positioning part, the positioning part of the rear gland is provided with a plurality of second threaded holes, when the rear gland is detachably connected with the outer packing box, the connecting part of the rear gland is inserted into the interior of the tail end of the outer packing box, the positioning part of the rear gland abuts against the tail end of the outer packing box, and each first threaded hole corresponds to a second threaded hole and communicates with the second threaded hole, bolts are sequentially arranged in the second threaded holes and the first threaded holes, and the rear gland is detachably connected with the outer packing box.

[0012] Optionally, an inclined angle is arranged on the inner side of the front end of the outer packing box.

[0013] The device has the following beneficial effects:

[0014] (1) The outer filler box is detachably connected with the rear end of the original filler box, so that the device can be installed on site in real time, and the installation is simple, convenient operation does not need to fire, and the troubleshooting time is within 4 hours; based on this, if each device is pre-installed after maintenance, the troubleshooting time will be shortened to 15 minutes, which greatly avoids the possibility of leakage of high-temperature flue gas mixed with catalyst to erode the valve rod, causing leakage accidents.

[0015] (2) The installation of the device can avoid unplanned emergency shutdown caused by failure, save 15 days of start-up and shutdown time at a time, reduce costs of more than 100 million yuan, and reduce oil slurry processing loss of 160-180T / h.

[0016] (3) The device has low processing cost, and the material is convenient to store and can be recycled, and can be 100% pre-stored.

[0017] (4) The device has carried out feasibility calculation, and the device body quality and operation meet the design requirements; it can meet the long-period safe operation. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structure diagram of the catalytic cracking cold wall slide valve filler leakage repair device in the present application;

[0019] Figure 2 is Figure 1 is an enlarged view of part A;

[0020] Figure 3 is a structure diagram of the annular positioning plate in the present application;

[0021] Figure 4 is an assembly positioning diagram of the catalytic cracking cold wall slide valve filler leakage repair device in the present application when installing.

[0022] BRIEF DESCRIPTION OF DRAWINGS:

[0023] 1, external filler box; 101, front end; 102, middle part; 103, tail end; 2, rear gland; 201, connecting part; 202, positioning part; 3, glue injection pipe interface; 4, steam cooling protection pipe interface; 5, sealing filler ring; 6, spare filler ring; 7, filler spacing ring; 8, annular positioning plate; 9, positioning hole; 10, first threaded hole; 11, second threaded hole; 12, valve rod; 13, rear end of original filler box. DETAILED DESCRIPTION

[0024] First part: device structure

[0025] Reference Figures 1-4The application discloses a catalytic cracking cold wall slide valve packing leakage repairing device, which comprises an external packing box 1 and a rear gland 2.

[0026] The front end 101 of the external packing box 1 is internally provided with an inclined angle, which can play a guiding role when the external packing box 1 is inserted between the valve rod 12 and the rear end 13 of the original packing box. The outer wall of the front end 101 of the external packing box 1 is sleeved with a ring-shaped positioning plate 8, the ring-shaped positioning plate 8 is fixedly connected with the front end 101 of the external packing box 1 and is integrally formed with the front end 101 of the external packing box 1, and the central axis of the ring-shaped positioning plate 8 coincides with the central axis of the front end 101 of the external packing box 1. A plurality of positioning holes 9 (four positioning holes 9 are arranged in the embodiment) are arranged on the plate surface of the ring-shaped positioning plate 8 and are arranged in a ring-shaped array with the central axis of the ring-shaped positioning plate 8 as the center. When the external packing box 1 is detachably connected with the rear end 13 of the original packing box, the front end 101 of the external packing box 1 is inserted into the rear end 13 of the original packing box, so as to extrude the packing. The plate surface of the ring-shaped positioning plate 8 abuts against the rear end 13 of the original packing box, the positioning holes 9 are in one-to-one correspondence with the holes arranged in the rear end 13 of the original packing box and are in communication with the holes, and the ring-shaped positioning plate 8 is fixed by 4*M12 bolts. The tail end 103 of the external packing box 1 is provided with a plurality of first threaded holes 10, the rear gland 2 comprises a connecting portion 201 and a positioning portion 202, the positioning portion 202 of the rear gland 2 is provided with a plurality of second threaded holes 11, when the rear gland 2 is detachably connected with the external packing box 1, the connecting portion 201 of the rear gland 2 is inserted into the tail end 103 of the external packing box 1, the positioning portion 202 of the rear gland 2 abuts against the tail end 103 of the external packing box 1, each first threaded hole 10 is in communication with a second threaded hole 11, bolts are sequentially inserted into the second threaded holes 11 and the first threaded holes 10, and the rear gland 2 is detachably connected with the external packing box 1.

[0027] The central axis of the front end 101 of the external packing box 1, the central axis of the tail end 103 of the external packing box 1 and the central axis of the middle part 102 of the external packing box 1 coincide. Through the integral design of the external packing box 1 and the positioning effect of the ring-shaped positioning plate 8, the coaxiality deviation between the device and the actuator of the equipment body during installation is greatly reduced, and the device can be guaranteed.

[0028] Since the inside of the external packing box 1 is provided with a cavity for packing, the internal pressure is large during the operation after the device is installed, and the diameter of the front end 101 of the external packing box 1 and the diameter of the tail end 103 of the external packing box 1 are both smaller than the diameter of the middle part 102 of the external packing box 1, which is beneficial to guarantee the wall thickness of the middle part 102 of the external packing box 1, thereby being more resistant to pressure. The inner wall of the external packing box 1 is provided with a sealing packing ring 5 and a standby packing ring 6, both of which are cavities with added packing. The standby packing ring 6 is located near the front end 101 in the internal cavity of the external packing box 1, and the sealing packing ring 5 is located near the tail end 103 in the internal cavity of the external packing box 1. A packing spacing ring 7 for partitioning is arranged between the sealing packing ring 5 and the standby packing ring 6, and the packing spacing ring 7 is annular and made of metal. The sealing packing ring 5 and the standby packing ring 6 are arranged in sequence to form a stepped series structure on the inner wall of the external packing box 1. During packing, the packing is installed through a packing pressing sleeve, and a coil-by-coil pressing method is adopted. The static friction of the packing is smaller than the thrust of the valve rod 12 of the cold wall slide valve.

[0029] Second part: feasibility calculation of oil cylinder piston force

[0030] The catalytic cracking cold wall slide valve packing leakage repair device designed in the application utilizes the original packing gland for bolt connection and fixation, is positioned at the connecting partition plate between the actuator of the equipment body and the valve body, and can fully meet the working needs through oil cylinder piston force feasibility calculation, so that the catalytic slide valve can be used for a long period of time.

[0031] The newly added packing needs to ensure that the slide valve rod 12 can freely move under the action of the oil cylinder, ensure that there is no jamming phenomenon, and ensure that the oil cylinder piston has sufficient axial force to overcome the friction of the newly installed packing, so as to meet the needs of normal operation of the device after installation.

[0032] The calculation process includes the following contents:

[0033] The required basic parameters are obtained: cylinder diameter of oil cylinder: D = 150mm; working state oil pump pressure: P min = 6MPa, P max = 10MPa;

[0034] The packing material is graphite, the material of the valve rod 12 is steel, the friction coefficient μ of graphite and steel is 0.4; the pressure of the packing and the valve rod 12 is derived from the positive pressure F N of the bolt, according to the test results, F N is taken as 3.5*10 6 N.

[0035] Through force analysis, the following calculation formula is obtained:

[0036] Cylinder piston area: S = π * (D / 2) 2 = 3.14 * (0.15 / 2) 2 = 0.18 m 2 ;

[0037] Valve stem minimum thrust: F 推 = P min / S = 6 * 10 6 / 0.18 = 3.33 * 10 7 N;

[0038] Static friction force of packing: F 摩 = μ * F N = 0.4 * 3.5 * 10 6 = 1.4 * 10 6 N;

[0039] Feasibility analysis: Because F 摩 < F 推 , the valve stem minimum thrust F 推 (i.e. the minimum force of the hydraulic control unit) can fully push the slide valve to work normally, indicating that this design is safe and controllable.

[0040] Part III: Example application and description

[0041] In petrochemical enterprises, long-term operation of heavy oil catalysis has been the direction of industry exploration, and long-term safe use of cold wall slide valve is an important problem restricting the long-term operation of catalytic cracking unit. In production operation, since the current device automation control has reached 100%, the slide valve is under automatic control, and the valve stem 12 and the packing at this position are always in low-frequency small-stroke relative sliding, and there is cooling and blowing steam injection at the sealing position.

[0042] China Petroleum Jinxi Petrochemical Branch 1.8 * 10 6 t / a heavy oil catalytic cracking unit, semi-regenerative slide valve is installed on the inclined pipe of the catalytic cracking unit regenerator to control the regenerator pressure, so that it is consistent with the reactor pressure, and the opening of the valve is adjusted according to the pressure difference between the regenerator and the reactor, through the pneumatic pressure difference regulator to send pneumatic signal, so that the hydraulic control unit on the valve is automatically adjusted. Among them, the main parameters of semi-regenerative slide valve are shown in Table 1.

[0043] Table 1 Main parameters of semi-regenerative slide valve

[0044] Main parameters Data Design pressure / MPa 0.6 MPa Design pressure difference / MPa 0.15 MPa Design temperature / °C 500-780℃ Total open area / m 2 ]] 0.18m 2 ]]> Valve full stroke / mm 540 mm

[0045] Fault cause analysis: During the operation of the slide valve, 700℃ high-temperature flue gas entrains catalyst particles along the direction of the valve stem 12, and the leakage reasons mainly include the following aspects:

[0046] ① Installation of packing quality problem, resulting in failure after work.

[0047] ② Valve stem 12 cooling blowout steam is too large, causing the valve stem 12 erosion leakage.

[0048] ③ Valve body thermal expansion, compression valve stem 12 stress and packing box different.

[0049] ④ Production process operation fluctuation is too large, the valve stem 12 and packing wear effect.

[0050] When the original packing box in the slide valve leakage occurs, 700℃ flue gas catalyst in the packing site injection, a short time will cause the sealing site packing damage, valve stem 12 blow injury and a series of serious problems. In the past, the treatment measures, generally take high pressure glue gun to the spare packing ring 6, for safety considerations, can not be replaced on-line working packing, which leads to leakage can not be solved immediately, resulting in emergency shutdown, loss of more than 10 million.

[0051] In the past, the site leakage repair way, generally adopt the way of welding packing box repair, but this way after processing, on the one hand, the installation precision can not be guaranteed, on the other hand, the welding deformation is large, the coaxiality deviation is large (even reach millimeter level), the damage to the equipment body is large, the welding after a short period of time still need to replace the whole equipment, but also increase the equipment repair cost. Because of the leakage gas containing CO, and the operation space is small, the operation risk is great; welding after the valve body, the external welding packing box are deformed, the coaxiality can not be guaranteed in a small error range.

[0052] The installation process of the external packing box 1 designed in the application is as follows: the new external packing box 1 is installed to remedy the leakage of the heavy oil catalyst DYLD1000 semi-regenerative slide valve, and the operation method is as follows: after the original packing box of the valve body is completely invalid, the new external packing box 1 is installed at the position of the slide valve packing part and the transmission part connecting partition. The external packing box 1 is installed on the original packing box body by using the original packing box gland fastening bolt, so that the workers do not need to work in the narrow operation space for a long time, which is beneficial to ensure the safety operation of the workers.

[0053] The external packing box 1 designed in the application is a one-piece structure that completely fits the equipment, can be installed on site in real time, and is simple to install, does not require on-site welding, is convenient to operate without fire, and can be completed within 4 hours of troubleshooting. Specifically, the front end 101 of the external packing box 1 of the device is positioned and connected through the positioning holes 9 on the annular positioning plate 8 using 4*M12 bolts, and the outer diameter of the tail end 103 of the external packing box 1 connected to the rear gland 2 cooperates with the positioning partition hole of the equipment body, so as to ensure that the coaxiality deviation between the external packing box 1 and the actuator of the equipment body is at a low level (note: the original installation of a lip seal can be removed, and individual small size can be removed from the actuator for turning). In the event of a valve stem 12 packing leakage accident during device operation, a safe, fast and reliable external packing box 1 is installed, so that the fault can be quickly solved, and the equipment is ensured to be in long period. The device has low processing cost, the material is convenient to store, and can be recycled, and can be 100% pre-stored.

[0054] If each device is pre-installed after maintenance, the troubleshooting time will be shortened to 15 minutes, so that the possibility of leakage of high-temperature flue gas mixed with catalyst erosion of the valve stem 12 can be greatly avoided, and the possibility of leakage accident cannot be repaired in time. The installation of the device can avoid unplanned emergency shutdown caused by failure, according to actual calculation, the single saving start-up and shutdown time is 15 days, the cost is reduced by more than 10 million yuan, and the oil slurry processing amount loss is reduced by 160-180T / h.

[0055] In the device described in the application, the one-piece external packing box 1 is the main design component, the front end 101 of which is designed in the form of the original packing box gland (i.e. when the external packing box 1 is detachably connected with the rear end 13 of the original packing box, the front end 101 of the external packing box 1 is correspondingly inserted into the inside of the rear end 13 of the original packing box, and the plate surface of the annular positioning plate 8 abuts against the rear end 13 of the original packing box), and is fastened by 4*M12 bolts; the tail end 103 cooperates with the transmission box partition (the transmission box partition is not shown in the drawing), the positioning installation and control of the radial gap of the one-piece external packing box 1 ensure that the coaxiality error between the external packing box 1 and the valve stem 12 after installation is less than 0.10mm, and through this design, only the transmission box and the oil cylinder need to be removed during installation, and the tail end is positioned after installation, which ensures the long-period use of the facility after installation.

[0056] The application result is: through reasonable design calculation and improvement of the packing pressing mode, the external packing device installed in the original space of the slide valve has been safely operated for more than 36 months, and no leakage accident occurs again, the slide valve stem 12 is sensitive and has no jamming phenomenon, which proves that the design is successful, avoids the non-planned emergency shutdown of the heavy oil catalytic cracking device, and ensures the smooth completion of the annual production task of the company. In the above process of packing and pressing of the slide valve, the quality of the parts is strictly inspected, unqualified products are not installed, and the external packing box 1 is appropriately reserved to ensure the production demand and meet the requirements of long-period operation of the device.

[0057] The above merely describes the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make equivalent replacement or change according to the technical scheme and concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A catalytic cracking cold wall spool valve packing leak repair device characterized by, Include external filler The box (1) and the rear gland (2), the external filler box (1) is of integral structure, the inside of the external filler box (1) is provided with filler cavity, the rear gland (2) is detachably connected with the external filler box (1);When the external filler box (1) is installed with cold wall slide valve device, one end of the external filler box (1) is detachably connected between the original filler box rear end (13), the other end of the external filler box (1) is matched with the transmission box body partition, and the valve stem (12) of the cold wall slide valve is arranged in the inside of the external filler box (1); The external filler box (1) comprises front end (101), middle part (102) and tail end (103) arranged in sequence, the center axis of the front end (101) of the external filler box (1), the center axis of the tail end (103) of the external filler box (1) and the center axis of the middle part (102) of the external filler box (1) coincide, the diameter of the front end (101) of the external filler box (1) and the diameter of the tail end (103) of the external filler box (1) are both less than the diameter of the middle part (102) of the external filler box (1);When the external filler box (1) is detachably connected between the original filler box rear end (13), the front end (101) of the external filler box (1) is correspondingly inserted into the inside of the original filler box rear end (13); The outer wall of the front end (101) of the external filler box (1) is fixedly sleeved with the annular positioning plate (8) which is integrally formed with the front end (101) and extends outwardly, the center axis of the annular positioning plate (8) coincides with the center axis of the front end (101) of the external filler box (1), a plurality of positioning holes (9) are arranged on the plate surface of the annular positioning plate (8), and the plurality of positioning holes (9) are arranged in annular array with the center axis of the annular positioning plate (8) as the center;When the external filler box (1) is detachably connected between the original filler box rear end (13), the plate surface of the annular positioning plate (8) abuts against the original filler box rear end (13), the positioning holes (9) and the holes of the original filler box rear end (13) are communicated one by one, and are fixed by bolts; The inner side of the front end (101) of the external filler box (1) is provided with an inclined angle.

2. The catalytic cracking cold wall slide valve packing leak repair apparatus of claim 1 wherein, The inner wall of the external filler box (1) is provided with a sealing filler ring (5) and a standby filler ring (6), the sealing filler ring (5) and the standby filler ring (6) are both cavity structures with filler added, and a filler spacing ring (7) is arranged between the sealing filler ring (5) and the standby filler ring (6) to play a partitioning role.

3. The catalytic cracking cold wall slide valve packing leak repair apparatus of claim 2 wherein, The sealing filler ring (5), the filler spacing ring (7) and the standby filler ring (6) are arranged in sequence to form a stepped series structure on the inner wall of the external filler box (1).

4. The catalytic cracking cold wall slide valve packing leak repair apparatus of claim 2 wherein, The static friction force of the filler is less than the thrust of the valve stem (12) of the cold wall slide valve.

5. The catalytic cracking cold wall slide valve packing leak repair apparatus of claim 1 wherein, The tail end (103) of the external packing box (1) is provided with a plurality of first threaded holes (10), the rear gland (2) comprises a connecting part (201) and a positioning part (202), the positioning part (202) of the rear gland (2) is provided with a plurality of second threaded holes (11), when the rear gland (2) is detachably connected with the external packing box (1), the connecting part (201) of the rear gland (2) is inserted into the inside of the tail end (103) of the external packing box (1), the positioning part (202) of the rear gland (2) abuts against the tail end (103) of the external packing box (1), and each first threaded hole (10) is communicated with one second threaded hole (11) in correspondence, bolts are sequentially inserted into the second threaded holes (11) and the first threaded holes (10) and the rear gland (2) is detachably connected with the external packing box (1).

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