Method for replacing coke oven bridge pipe valve body and sealing socket

Abstract

The application discloses a method for replacing a coke oven bridge pipe valve body and a sealing socket online, and comprises the following steps: step one, dismounting; step two, determining; step three, adding; step four, hoisting; step five, mounting; step six, sealing; and step seven, detecting; in the step one, 8 copper wrenches are used to dismount 12 valve body flange screws installed at the valve body flanges one day before replacement; if the valve body flange screws are seriously corroded, the valve body flange screws are treated by water welding cutting; meanwhile, 4 valve body flange screws installed at the corners are reserved; normal connection of the old valve body is ensured; new valve bodies, asbestos ropes, mud materials and other sealing materials required for the next day replacement are prepared; the application replaces the bridge pipe valve body for leading out raw coal gas under the non-stop production state of the coke oven and seals the socket, so that the phenomenon of raw coal gas leakage and ammonia water running at the damaged valve body and the socket is treated online, which is of great significance for the smooth leading out of the raw coal gas of the coke oven and the improvement of the environmental pollution of the coke oven.

Description

Technical Field

[0001] This invention relates to the field of coke oven maintenance technology, specifically a method for online replacement of coke oven bridge pipe valve bodies and sealing sockets. Background Technology

[0002] The coke oven valve body, also known as a water seal valve, connects the riser pipe and the gas collecting pipe, and is used to cut off or open the raw coal gas flowing into the carbonization chamber and its pipes. The opening and closing operation is accomplished by lowering or raising the valve disc. When the valve disc is raised, a 40mm water seal is formed in the disc due to sprayed ammonia water, preventing raw coal gas from the carbonization chamber from entering the gas collecting pipe. When the water seal flap is tilted, the water seal is lost, allowing raw coal gas from the carbonization chamber to enter the gas inlet pipe. The valve body is fixed to the gas collecting pipe, and its upper part is connected to the bridge pipe via a socket joint. Most gas collecting pipes have a circular cross-section, with a circular hole on the side for connection to the valve body via a short section. Generally, as coke ovens age, cracks and fissures in the valve body become increasingly common. Initially, methods such as using packing straps are effective, but over time, the seal at the valve body cracks and the riser pipe socket deteriorates, leading to serious leakage of raw coal gas and ammonia water. Therefore, it is necessary to replace the bridge pipe valve body and simultaneously ensure effective sealing at the socket joint.

[0003] Valve bodies are mostly cast from gray cast iron. During casting, process issues can lead to sand holes and cracks in the castings. The raw coal gas from the carbonization chamber enters the gas collecting pipe and is cooled by a safety spray at the bridge pipe. If the spraying is inadequate, the valve body temperature may rise above 300 degrees Celsius, generating thermal stress. This can cause sealing problems at the socket joint. As the coke oven age increases, it is prone to cracking, and the leaked ammonia water can damage the oven body. If it flows onto the furnace columns or doors, it can damage the furnace protective iron components, reducing the coke oven's service life. If it flows into the carbonization chamber, it can damage the furnace bricks. Because coke ovens are continuously operating equipment, production cannot be stopped for maintenance due to this problem. Therefore, an online solution to this problem must be found. Summary of the Invention

[0004] The purpose of this invention is to provide a method for online replacement of the valve body and sealing socket of a coke oven bridge pipe, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for online replacement of coke oven bridge pipe valve body and sealing socket, comprising the following steps: Step 1, disassembly; Step 2, identification; Step 3, installation; Step 4, lifting; Step 5, installation; Step 6, sealing; Step 7, testing;

[0006] In step one above, the day before replacement, remove 8 of the 12 valve body flange bolts installed at the valve body flange using a copper wrench. If the valve body flange bolts are severely corroded, use water welding to cut them off, while retaining the valve body flange bolts installed at the four corners; ensure the normal connection of the old valve body, clean the socket, test the corresponding circulating ammonia valve to confirm that the opening and closing is flexible; prepare the new valve body to be replaced the next day, asbestos rope, mud, and other sealing materials.

[0007] In step two above, the valve body replacement time is determined to be at the end of the coking period of the furnace number to be replaced, that is, 2-3 hours before the coke matures; when the determined replacement time is reached, the machine-side and coke-side control valves of the combustion chamber corresponding to the furnace number to be replaced are closed to 2 / 3.

[0008] In step three above, the riser cover switch on the riser water seal trough is opened, the riser cover is pressed down, and the riser cover is fixed with wire; the coke side coal feeding port cover is opened, and then the chimney is installed at the coke side coal feeding port cover position to ensure that the heat of the carbonization chamber is discharged from here to avoid the generation of ignition sources at the original valve body, which may cause combustion or explosion.

[0009] In step four above, the valves on the high-pressure ammonia sprayer and the circulating ammonia valve are closed, and the ammonia transport pipeline is disassembled; the bridge pipe is secured with a steel wire rope, and the bridge pipe and riser are lifted by a crane and placed in a position that will not affect the replacement of the valve body; the riser pipe is cleaned to ensure that there are no flammable materials and the surface is flat, a steel plate is laid at the base of the riser, an asbestos pad is laid on the steel plate, and the surrounding area is compacted;

[0010] In step five above, the old valve body is secured with a steel wire rope, and the pressure of the gas collecting pipe is manually adjusted to 30-70 Pa by adjusting the gas collecting pipe pressure regulating valve; the last four valve body flange bolts are removed, the old valve body is removed, and the flange opening is quickly blocked with a blind plug to prevent smoke from escaping, and the blind plate is tightened; or all valve body flange bolts are removed and the flange is quickly plugged with a wooden plug; the old flange gasket is cleaned; the new valve body is hoisted to the top of the furnace, directly above it, and the blind plug or wooden plug is quickly removed, the valve body is lowered, aligned with the flange opening, and the four diagonally opposite valve body flange bolts are installed;

[0011] In step six above, the new valve body flap is closed, the socket is sealed using a five-layer packing mixed technology, the new valve body is tightened using the remaining valve body flange bolts, and then the gas collecting pipe pressure is restored and switched to automatic adjustment; the iron plate and asbestos gasket installed at the root of the riser are removed, and the riser and riser are lifted and placed in place; the pipelines are connected, and then the valves installed on the high-pressure ammonia spray and the circulating ammonia valve are opened, the chimney installed on the coke side coal feeding port cover is removed, and the coke side coal feeding port cover is installed; the machine side feed and de-feed valves and the coke side feed and de-feed valves are fully opened;

[0012] In step seven above, the oxygen content analyzer of the gas after the blower is monitored. When the online oxygen content is 0-0.8%, the manual detection and verification are completed, and the electrostatic precipitator of the recovery system is turned on. The electrostatic precipitator is connected to the gas primary cooler, and the gas primary cooler is connected to the gas collection pipe.

[0013] Preferably, in step two, the combustion chamber temperature is controlled at 1200℃, and the combustion chamber is provided with an organic side coal feeding hole cover and an intermediate coal feeding hole cover.

[0014] Preferably, in step three, compressed air is used to push the remaining raw coal gas out of the chimney at the coke side feed port through the riser pipe to clean the riser pipe, close the flap, and then use mud to seal the flap installed on the old valve body to ensure a tight seal.

[0015] Preferably, in step four, the operation of the electrostatic precipitator is stopped; the electrostatic precipitator power distribution room is grounded to prevent safety accidents caused by excessive oxygen content in the electrostatic precipitator.

[0016] Preferably, in step five, if there is pressure fluctuation in the gas collection pipe, the flap installed in the new valve body can be opened to release pressure.

[0017] Preferably, in step six, the specific proportions of the five layers of filler are as follows: asbestos packing (φ30mm, high temperature resistant 1000-1500℃) is laid on the first layer of the insertion joint, and after being evenly compacted, river sand with a specific thickness of (10-15mm) is laid on top as the second layer; petroleum asphalt is laid on the third layer as a binder; asbestos packing is used again for the fourth layer and compacted; the fifth layer uses a mixture of 20% iron concentrate, 40% cast iron filings, and 40% petroleum asphalt, with a final thickness of 15-20mm.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1) During the replacement of the furnace number, a self-made chimney is used to facilitate the heat source to be discharged from the coal feeding port on the coke side, which effectively avoids the combustion caused by gas leakage when the valve body is replaced.

[0020] 2) Before replacement, retain the 4 screws at the connection between the old valve body flange and the gas collection pipe. This can not only effectively stabilize the connection, but also enable a quick and efficient replacement of the new valve body, thus avoiding a large amount of raw coal gas leakage.

[0021] 3) The entire process is carried out using copper tools, which effectively avoids the risk of explosion caused by sparks generated during the replacement due to hammering and friction;

[0022] 4) The electrostatic precipitator of the recovery system has been added to stop and start the operation, which eliminates the safety accidents caused by air being drawn into the gas pipeline in front of the blower when the valve body is changed and opened.

[0023] 5) The self-made formula riser pipe spigot sealing technology adopts a five-layer sealing method, which effectively solves the accident of leakage caused by poor sealing at the new valve body and the original spigot.

[0024] 6) When replacing, control the pressure of the gas collection pipe within the range of 30-70pa according to the amount of raw coal gas that escapes after the old valve body is removed, so as to avoid a large amount of raw coal gas escaping and causing serious impact on the operator's vision and sense of smell. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method of the present invention;

[0026] Figure 2 This is a schematic diagram illustrating the method for online replacement of the coke oven bridge pipe valve body and sealing socket in this invention.

[0027] In the diagram: 1. Electrostatic precipitator for tar removal; 2. Primary gas cooler; 3. Gas collecting pipe pressure regulating valve; 4. Circulating ammonia water valve; 5. Gas collecting pipe; 6. Valve body flange bolts; 7. Flip plate; 8. Socket; 9. Bridge pipe; 10. High-pressure ammonia water spray; 11. Ascending pipe water seal trough; 12. Ascending pipe cover switch; 13. Coke side add / remove valve; 14. Machine side coal feeding hole cover; 15. Intermediate coal feeding hole cover; 16. Coke side coal feeding port cover; 17. Machine side add / remove valve; 18. Riser; 19. Ascending pipe. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1-2 The present invention provides an embodiment of a method for online replacement of the valve body and sealing socket of a coke oven bridge pipe, comprising the following steps: Step 1, disassembly; Step 2, identification; Step 3, installation; Step 4, lifting; Step 5, installation; Step 6, sealing; Step 7, testing.

[0030] In step one above, the day before replacement, remove 8 of the 12 valve body flange bolts 6 installed at the valve body flange using a copper wrench. If the valve body flange bolts 6 are severely corroded, use water welding to cut them off, while retaining the valve body flange bolts 6 installed at the four corners; ensure the normal connection of the old valve body, clean the socket 8, test the corresponding circulating ammonia valve 4 to confirm that the opening and closing is flexible; prepare the new valve body to be replaced the next day, asbestos rope, mud, and other sealing materials.

[0031] In step two above, the valve body replacement time is determined to be at the end of the coking period of the furnace number to be replaced, that is, 2-3 hours before the coke matures; when the determined replacement time is reached, the machine-side add / subtract valve 17 and the coke-side add / subtract valve 13 of the combustion chamber corresponding to the furnace number to be replaced are closed to 2 / 3, the combustion chamber temperature is controlled at 1200℃, and the machine-side coal feeding hole cover 14 and the intermediate coal feeding hole cover 15 are installed on the combustion chamber;

[0032] In step three above, the riser cover switch 12 on the riser water seal trough 11 is opened, the riser cover is pressed down, and the riser cover is fixed with wire; the coke side coal feeder cover 16 is opened, and then the chimney is installed at the position of the coke side coal feeder cover 16 to ensure that the heat of the carbonization chamber is discharged from here to avoid the generation of ignition sources at the original valve body, which could cause combustion or explosion; compressed air is used to push the remaining raw coal gas out of the chimney of the coke side coal feeder through the riser 19 to clean the riser 19, the flap 7 is closed, and then the flap 7 on the old valve body is sealed with mud to ensure a tight seal;

[0033] In step four above, the valves on the high-pressure ammonia spray 10 and the circulating ammonia valve 4 are closed, and the ammonia transport pipeline is dismantled; the bridge pipe 9 is secured with a steel wire rope, and the bridge pipe 9 and the riser pipe 18 are lifted by a crane and placed in a position that will not affect the replacement of the valve body; the riser pipe 19 is cleaned to ensure there are no flammable materials and the surface is flat, a steel plate is laid at the base of the riser pipe 18, an asbestos pad is laid on the steel plate, and the surrounding area is compacted; the operation of the electrostatic precipitator 1 is stopped; the electrostatic precipitator power distribution room is grounded to prevent safety accidents caused by excessive oxygen content in the electrostatic precipitator 1;

[0034] In step five above, the old valve body is secured with a steel wire rope, and the pressure of the gas collecting pipe 5 is manually adjusted to 30-70 Pa by adjusting the gas collecting pipe pressure regulating valve 3; the last four valve body flange bolts 6 are removed, the old valve body is removed, and the flange opening is quickly blocked with a blind plug to prevent smoke from escaping, and the blind plate is locked; or all the valve body flange bolts 6 are removed and the flange is quickly plugged with a wooden plug; the old flange gasket is cleaned; the new valve body is hoisted to the top of the furnace, directly above it, and the blind plug or wooden plug is quickly removed, the valve body is lowered, the flange opening is aligned, and the four diagonal valve body flange bolts 6 are installed; if there is pressure fluctuation in the gas collecting pipe 5, the flap 7 installed in the new valve body can be opened to release pressure;

[0035] In step six above, the new valve body flap 7 is closed, and the socket 8 is sealed using a five-layer packing mixture technique. The new valve body is then secured with the remaining valve body flange bolts 6. The pressure of the gas collecting pipe 5 is then restored and switched to automatic adjustment. The iron plate and asbestos gasket at the root of the riser pipe 18 are removed, and the riser pipe 19 and riser pipe 18 are lifted and placed in place. The pipelines are connected, and then the valves on the high-pressure ammonia spray 10 and the circulating ammonia valve 4 are opened. The chimney on the coke side coal feeder cover 16 is removed, and the coke side coal feeder cover 16 is cleaned. 6. Install the equipment; fully open the machine-side adjustment valve 17 and the coke-side adjustment valve 13; the specific proportions of the five-layer packing are as follows: lay asbestos packing (φ30mm, high temperature resistant 1000-1500℃) in the first layer at the spigot, compact it evenly, and then lay river sand on top with a thickness of (10-15mm) as the second layer; lay petroleum asphalt as the adhesive in the third layer, continue to use asbestos packing in the fourth layer and compact it; the fifth layer uses a mixture of 20% iron concentrate, 40% cast iron filings, and 40% petroleum asphalt, with a thickness of 15-20mm after laying;

[0036] In step seven above, the oxygen content analyzer of the gas after the blower is monitored. When the online oxygen content is 0-0.8%, the manual detection and verification are completed, and the electrostatic precipitator 1 of the recovery system is turned on. The electrostatic precipitator 1 is connected to the gas primary cooler 2, and the gas primary cooler 2 is connected to the gas collecting pipe 5.

[0037] Based on the above, the advantages of this invention are that it can be used without interrupting production, ensuring the smooth operation of the coke oven and preventing any loss of coke output; the resulting environmental problems can be effectively addressed online, providing a reference for online equipment replacement in the coking industry; using this invention can avoid environmental pollution caused by poor exhaust of raw coal gas and serious losses of chemical products due to ineffective recovery of raw coal gas, as well as daily penalties from environmental protection departments; it will not affect normal coke oven production, and the consumption of labor and materials is relatively small, greatly improving the safety factor of the operation.

[0038] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for online replacement of the coke oven bridge pipe valve body and sealing socket, including the following steps: Step 1, disassembly; Step 2, confirmation; Step 3, installation; Step 4, lifting; Step 5, installation; Step 6, sealing; Step 7, testing; Its features are: In step one above, the day before replacement, remove 8 of the 12 valve body flange bolts (6) installed at the valve body flange with a copper wrench. If the valve body flange bolts (6) are severely corroded, use water welding to cut them off. At the same time, keep the valve body flange bolts (6) installed at the four corners. Ensure the normal connection of the old valve body, clean the socket (8), test the corresponding circulating ammonia valve (4) to confirm that the opening and closing is flexible. Prepare the new valve body to be replaced the next day, asbestos rope, mud and other sealing materials. In step two above, the valve body replacement time is determined to be at the end of the coking period of the furnace number to be replaced, that is, 2-3 hours away from the coke maturity; when the determined replacement time is reached, the machine side add / remove valve (17) and coke side add / remove valve (13) of the combustion chamber corresponding to the furnace number to be replaced are closed to 2 / 3. In step three above, the riser cover switch (12) set on the riser water seal trough (11) is opened, the riser cover is pressed down, and the riser cover is fixed with iron wire; the coke side coal feeding port cover (16) is opened, and then the chimney is installed at the position of the coke side coal feeding port cover (16) to ensure that the heat of the carbonization chamber is discharged from here to avoid the generation of fire source at the original valve body, which may cause combustion or explosion; In step four above, the valves on the high-pressure ammonia spray (10) and the circulating ammonia valve (4) are closed, and the ammonia transport pipeline is disassembled; the bridge pipe (9) is tied with a steel wire rope, and the bridge pipe (9) and the riser pipe (18) are lifted by a crane and placed in a position that does not affect the replacement of the valve body; the riser pipe (19) is cleaned, free of flammable materials and with a flat surface, and a steel plate is laid at the root of the riser pipe (18), and an asbestos pad is laid on the steel plate and compacted around it; the operation of the electrostatic precipitator (1) is stopped; the electrostatic precipitator power distribution room is grounded to prevent the electrostatic precipitator (1) from causing a safety accident due to excessive oxygen content; In step five above, the old valve body is tied with a wire rope, and the pressure of the gas collecting pipe (5) is manually adjusted to 30-70 Pa according to the gas collecting pipe pressure regulating valve (3); the last four valve body flange bolts (6) are removed, the old valve body is removed, and the flange opening is quickly blocked with a blind plug to prevent smoke from escaping, and the blind plate is locked; or all the valve body flange bolts (6) are removed and the wooden plug is quickly used to plug it; the old flange gasket is cleaned; the new valve body is hoisted to the top of the furnace and positioned directly above it, the blind plug or wooden plug is quickly removed, the valve body is lowered, the flange opening is aligned, and four diagonal valve body flange bolts (6) are installed. In step six above, the new valve body flap (7) is closed, the socket (8) is sealed using a five-layer packing mixed technology, the new valve body is tightened using the remaining valve body flange bolts (6), and the pressure of the gas collecting pipe (5) is restored and switched to automatic adjustment; the iron plate and asbestos pad installed at the root of the riser (18) are removed, and the riser pipe (19) and riser pipe (18) are lifted and placed in place; the pipeline is connected, and then the valves installed on the high-pressure ammonia spray (10) and the circulating ammonia valve (4) are opened, the chimney installed on the coke side coal feeding port cover (16) is removed, and the coke side coal feeding port cover (16) is installed; the machine side addition / reduction valve (17) and the coke side addition / reduction valve (13) are fully opened. The specific composition of the five-layer packing is as follows: Asbestos packing is laid in the first layer at the insertion point, and after being evenly compacted, a 10-15mm thick layer of river sand is laid on top as the second layer; petroleum asphalt is laid in the third layer as a binder; asbestos packing is used again in the fourth layer and compacted; the fifth layer uses a mixture of 20% iron concentrate, 40% cast iron filings, and 40% petroleum asphalt, with a final thickness of 15-20mm. The asbestos packing is φ30mm and resistant to high temperatures of 1000-1500℃. In step seven above, the oxygen content analyzer of the gas after the blower is monitored. When the online oxygen content is 0-0.8%, the manual detection and verification is completed, and the electrostatic precipitator (1) of the recovery system is turned on. The electrostatic precipitator (1) is connected to the gas primary cooler (2), and the gas primary cooler (2) is connected to the gas collection pipe (5).

2. The method for online replacement of coke oven bridge pipe valve body and sealing socket according to claim 1, characterized in that: In step two, the combustion chamber temperature is controlled at 1200℃, and an organic side coal feeding hole cover (14) and an intermediate coal feeding hole cover (15) are installed on the combustion chamber.

3. The method for online replacement of coke oven bridge pipe valve body and sealing socket according to claim 1, characterized in that: In step three, compressed air is used to push the remaining raw coal gas out of the coke side coal feeding port chimney through the riser pipe (19), the riser pipe (19) is cleaned, the flap (7) is closed, and then the flap (7) on the old valve body is sealed with mud to ensure a tight seal.

4. The method for online replacement of coke oven bridge pipe valve body and sealing socket according to claim 1, characterized in that: In step five, if there is pressure fluctuation in the gas collection pipe (5), the flap (7) set in the new valve body can be opened to release pressure.

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