Dry coke quenching equipment maintenance

6.1 Special accident handling and operation of dry coke quenching 6.1.1 The rotary seal valve is stuck (1) Phenomenon ① The rotary seal valve overload alarm appears on the CRT screen in the central control room. ②The coke transport system stopped running. (2) Reason ① There are steel plates and other debris in the coke. ②The coke block is too large or the coke discharge speed is too fast. ③Rotate. (3) Treatment ① Determine coke loading based on the CDQ furnace material level. When the CDQ furnace material level is high, the coke oven section should be notified immediately to use wet coke quenching. When the material level is low, the number of furnaces loaded can be reasonably arranged. If the rotary sealing valve does not return to normal, the coke oven should be notified to use wet coke quenching. ②Notify relevant maintenance personnel. ③Notify shop of stuck rotary seal valve. ④Operators go to the scene and bring walkie-talkies, carbon monoxide alarms, and oxygen analyzers. ⑤Reduce the circulating air volume to a minimum of about 36000m3/h, and stop the circulation fan if necessary. ⑥If the rotary seal valve is stuck due to coke, the problem of the rotary seal valve being stuck can usually be solved by inching and reversing the rotary seal valve. ⑦If iron or wood blocks the rotary seal valve, jog it to reverse the rotation of the rotary seal valve, which will loosen the ironware. If it cannot be moved even if it is reversed, it is forbidden to jog the rotary seal valve frequently to prevent the motor thermal protection from taking effect or the motor burning out. ⑧Stop the rotary seal valve to purge compressed air or nitrogen, open the maintenance manhole of the rotary seal valve, and use tools to remove debris. If the stuck part is inside the rotary seal valve, the circulation fan needs to be stopped and the air replaced. After the gas is tested to be qualified (O2>18%, CO<50ppm), the maintenance personnel can enter the rotary seal valve to remove the debris. ⑨Notify the power turbine power station that the rotary seal valve is stuck, and pay attention to monitoring the main steam pressure and main steam temperature. If the temperature and pressure drop significantly, notify the power workshop and close the main steam cut-off valve. ⑩After the treatment is completed, production should be resumed in a timely manner, and the coke oven should be notified to resume dry quenching according to the material level of the dry quenching furnace, and the power workshop should be notified that the rotary sealing valve has been restored. Notice: If the reducer of the rotary seal valve is damaged, the phenomenon will be the same as that of the rotary seal valve being stuck. However, if the reducer is damaged, it will not move at all in reverse. If this happens, the reducer should be checked. 6.1.2 The discharge device does not discharge coke 1) Phenomenon ① The coke discharge amount displayed by the belt scale fluctuates greatly, and the coke discharge amount continues to decrease, and the final coke discharge amount is displayed as zero. ②There is no fault alarm for the rotary sealing valve on the CRT screen in the central control room. The amplitude of the vibrating feeder is normal, but the vibrating sound is abnormal. (2) Reasons ① There may be ironware stuck in the upper part of the entrance of the vibrating feeder in the furnace. ②The installation number of the adjusting rods is larger and the insertion depth of each adjusting rod is deeper. (3) Treatment ① The central control personnel should go to the site to check the amount of coke on the belt. If there is less coke or no coke, it must be processed. ②Use a hammer to tap the upper part of the flat gate of the dry quenching furnace. If the coke discharge amount is stable after tapping, it means that the coke is stuck in the upper part of the vibrating feeder and no further treatment is required. ③If tapping still does not solve the problem, pull out the adjusting rods at each point of the dry quenching furnace. If the problem is solved, keep the adjusting rods as they are without further treatment. ④If the problem cannot be solved by pulling out the adjusting rod, it means that there is an iron plate or debris stuck on the upper part of the vibrating feeder. At this time, all the adjusting rods should be pulled out, and then the flat gate should be "closed" and "opened", and the opening stroke of the flat gate should be confirmed to be reached. If it is not reached, the flat gate should be pulled out with a hand chain hoist. ⑤Until the iron plate at the upper part of the inlet of the vibrating feeder falls into the rotating seal, perform the operations described in the previous section to remove the iron plate. ⑥After the focus discharge is stable, the installation position of the adjusting rod can be determined based on the temperature uniformity of points T4 and T3 or whether installation is not required. 6.1.3 Coke clamping in the rotating coke tank (1) Phenomenon ① There is a small amount of coke inside the rotating coke tank. ②The semi-open gate of the rotary coke tank does not fall flatly on the rotating disk, and both sides are tilted. (2) Reason ① The cast iron plate in the coke tank is not smooth. ②The gaps between cast iron plates are large. (3) Processing ① Notify the coke quenching vehicle to reverse for production. ②CDQ operators should bring iron drills, shovels, ladders, and walkie-talkies to the site. ③The operator goes to the coke tank to clean the coke, and mashes the coke caught in the semi-open gate with an iron drill. ④Notify the coke oven section to adopt wet coke quenching. ⑤Lift the coke tank to the upper limit of the lifting tower, and then use the vehicle to automatically place the coke tank on the coke tank truck. ⑥If the rotating coke tank is still uneven, use a vehicle to automatically lift the coke tank to the upper limit of the cooling tower, switch to manual coke loading, and use an air duct to purge the surface of the semi-open gate on the upper part of the coke loading hopper. ⑦After purging, manually lift the coke tank to the upper limit of the cooling tower, and then use the vehicle to automatically place the coke tank on the coke tank truck. ⑧After the treatment is completed, the coke oven is notified to use dry quenching. 6.1.4 Coke floating at the chute entrance (1) Phenomenon ① The circulating gas at the boiler inlet increases by -500~-1000Pa compared with the normal value. ②There are small pieces of coke accumulated in the dust cooling device at the bottom of the primary dust removal, blocking the rotary valve and preventing the coke from being discharged. ③The circulating air volume cannot be reduced normally. ④The coke floating phenomenon can be seen through the air inlet at the upper part of the annular air duct. (2) Cause ① The circulating air volume increases too quickly. ②The circulating air volume is too large and exceeds the ventilation capacity of the circulating air duct. ③The coke particle size is too small and the weight is light. ④Due to the uneven distribution of the charged coke around the dry quenching furnace, the flow rate changes too much. (3) The treatment operator goes to the site to confirm the floating phenomenon of coke. The following measures can be taken according to the degree of floating of coke.: When the degree is mild and discovered early, the coke discharge volume and circulating air volume can be reduced. After the floating phenomenon disappears, the coke discharge volume and circulating air volume can be slowly increased to restore the original operating state. When the coke floating phenomenon is serious, handle it as follows:: ①Notify the coke oven to use wet coke quenching. ②Minimize the circulating air volume while ensuring that the discharged coke temperature is below 205°C, and allow the coke to be continuously discharged to reduce the CDQ furnace material level. ③Keep the CDQ furnace material level above 300mm at the chute opening. When the material level is lower than this level, the coke discharge should be stopped. ④Contact the central control room and obtain the consent of the central control room. Use a long iron drill to poke the coke out of the chute. During the operation, special attention should be paid to preventing the iron drill from falling into the dry quenching furnace. ⑤Slowly increase the coke discharge volume and circulating air volume to restore the original operating state. ⑥Notify coke ovens to use dry quenching. 6.1.5 Coke overflows into the dry quenching furnace (1) Phenomenon ① The furnace cover does not move in the closing direction when it is installed. ②There was a lot of smoke and dust on the top of the dry quenching furnace, accompanied by fire. (2) Cause ① The material level meter is faulty and the loading continuous lock device fails. ②Careless operation and mistakes. (3) Treatment ① Use wet coke quenching in conjunction with the coke oven section. ②Under the condition of ensuring that the discharged coke temperature is less than 205°C, increase the coke discharge volume, reduce the material level of the dry quenching furnace as soon as possible, and pay attention to the matching of circulating air volume and coke discharge volume. ③When the loading device is operable, the furnace cover is manually closed on site. ④Extinguish the red coke around the installation with water and clean it up. Pay attention to monitor the combustible components of the circulating gas to make it within the specified range. ⑤After the accident is handled, at least three manual operations must be carried out on site. Only after passing the test can the coke loading operation be carried out according to the operating conditions. However, the first two cans of red coke must be loaded manually and can only be put into operation after confirmation. 6.1.6 The loading device cannot be started (1) Phenomenon ① The loading device cannot be started automatically or manually. ②There is a large amount of coke covering the loading device. (2) Cause ① There is a mechanical or electrical failure in the loading device. ②The loading device is covered and clogged with red burnt. (3) Treatment ① Notify the coke oven section to adopt wet coke quenching and notify the workshop. ②Inform inspection and relevant maintenance personnel to go to the site for inspection. ③The operator goes to the site to confirm the cause of the fault, takes appropriate treatment methods, and cooperates with the maintenance personnel to perform repairs. ④To ensure the normal and stable operation of the boiler, reduce the coke discharge amount according to the coke storage amount in the dry quenching furnace and the repair time of the loading device. However, when the normal material level cannot be maintained for a long time, the dry quenching furnace will maintain heat and pressure, notify the power, close the main steam cut-off valve, and steam will be released. ⑤When the loading device returns to normal, it is manually tested three times. When normal, the coke oven is notified to use dry quenching. The first two furnaces are manually loaded with coke. After normal operation, it is put into automatic operation. 6.1.7 Electric locomotive system 6.1.7.1 Coke tank cannot rotate: The coke jar suddenly failed to rotate when receiving red coke. reason: ①The coke pot received no signal to rotate. ②The PLC is faulty. ③Frequency converter failure. ④Rotating fan failure. Countermeasures: ①Check or replace the coke tank signal element. ②Reset the PLC, check the fault source, check the network source, and strengthen shielding. ③Reset and clear alarm. ④Check the main circuit or replace the rotating fan. 6.1.7.2 The coke tank cannot stop rotating: The coke tank cannot stop spinning after receiving red coke or during test run. reason: ①Rotary encoder failure. ②The coke tank alignment detection element is damaged. ③The stop command was not received by PLC. Countermeasures: ①Check or replace the encoder. ②Replace the detection element. ③Check the master control line or forced signal. 6.1.7.3 The coke tank stops during rotation: The rotation of the coke tank suddenly stopped during the process of receiving red coke or during test run. reason: ①The PLC is faulty. ②The frequency converter is faulty. ③Power failure. ④Rotary motor failure. Countermeasures: ①Perform PLC reset. ②Instantaneous alarms can be reset by the panel. ③Eliminate short circuits or ground faults in the power supply. ④If the machine fails, replace the motor. 6.1.7.4 The electric locomotive cannot run: The electric locomotive suddenly stopped moving while running. reason: ①The coke pot is out of alignment. ②The lock command is not reset. ③The frequency converter alarms. ④Mechanical failure. Countermeasures: ①Re-rotate the alignment or give a forced signal to bring the tank to the corrected position. ②The emergency stop command is reset. ③The panel is reset. ④Check the pneumatic brake or air circuit. 6.1.7.5 The command cannot be sent when the coke tank is full.: After the coke tank is aligned, a full tank command is issued, but the elevator does not work. reason: ①Is there any signal loss in the coke tank? ②The coke pot is out of alignment. ③The elevator EI system did not receive a signal. ④The APS action signal relay is broken. ⑤The APS action signal electromagnet is broken. ⑥The emergency stop command is reset. Countermeasures: ①Check or replace the detection element. ②Rotate again to align the coke pot. ③Replace relay. ④Replace the solenoid. ⑤Reset emergency stop button. 6.1.7.6 The command to receive empty tanks from an electric locomotive cannot be sent out: After the electric locomotive was aligned, the call was sent to pick up the empty tank, but the APS had no response. reason: ①The command was sent incorrectly. ②The command line for receiving empty tanks is faulty. ③Wrong selection of coke pot. ④The CDQ alignment signal cannot be received. Countermeasures: ①Re-issue the correct instructions (electric locomotive drivers are required to give clear and correct instructions). ②Check or replace the wiring. ③Choose the right coke pot. ④Check whether the signal is reliable or replace the detection component. 6.1.7.7 Failure to align the coke tank during rotation: The coke tank is not in the aligned position after the rotation of the coke collector stops or during the test run, causing the electric locomotive to fail to operate normally. reason: ①The encoder gear transmission mechanism is faulty. ②Encoder communication failure. ③The coke tank alignment detection element is faulty. Countermeasures: ①Replace the gear transmission mechanism. ②Check the communication network and reliably block it. ③Replace the detection element. 6.1.7.8 The electric locomotive cannot increase speed while traveling: The speed of the electric locomotive cannot be increased while running on the track, so the electric locomotive always runs at a low speed. reason: ①Master command failure. ②PLC integrated module output failure. ③DC24V power supply is grounded. Countermeasures: ①Replace the master controller. ②Replace the integrated output module. ③Check the grounding or obtain another DC24V power supply. 6.1.7.9 Brake failure of electric locomotives: While the electric locomotive was running on the track, the brakes suddenly failed and the electric locomotive had difficulty stopping. reason: ①The brake pads are badly worn. ②The compressed air pressure of electric locomotive pneumatic brakes is low. ③The cylinder does not move. Countermeasures: ①Replace brake pads. ②Increase compressed air pressure. ③Check whether each solenoid valve and pneumatic valve are normal, check whether each brake cylinder is intact and deal with it. 6.1.7.10 Coke tank lining falling off: On-site inspections or electric locomotive drivers discovered that the coke tank lining had fallen off. reason: ①The hook on the back of the liner is broken. ②The lining hook fixed beam is welded. ③The bottom door is jammed. ④Lining plate fixing bolt broken. Countermeasures: ①Replace the liner. ②Repair the fixed beam again. ③Clean the coke at the bottom of the coke tank and deal with the gaps. ④Replace the fixing bolts. 6.1.8 Hoisting system 6.1.8.1 Abnormalities in the operating status of the hoist: When the elevator is running automatically, the operating status is abnormal. reason: The original photoelectric limit is affected by dust and oil and produces false signals. Countermeasures: Change the limit selection and strengthen maintenance. 6.1.8.2 The hoist does not stop at the standby position: When the elevator automatically descends, it does not stop when it reaches the standby position and continues to descend. reason: The standby position limit is damaged or the detection piece deviates from the limit notch. Countermeasures: When this phenomenon occurs, the central control room should press the emergency button, notify the electrician to deal with it, replace the limit, install a guide frame on the limit, and add a rotating limit to serve as a standby position signal. 6.1.8.3 The elevator cannot lift and travel: After receiving the full tank signal, the elevator cannot perform lifting work. reason: Car PLC module 24V power line grounding ； The AC power supply from the elevator ground control cabinet to the vehicle module was damaged and short-circuited in the cable drag chain. Countermeasures: Use emergency systems to find ground points ； Find the fault point and insulate it. 6.1.8.4 Unstable lifting speed: The elevator's speed (high speed, low speed) is not stable during travel, and it stops and goes. reason: The speed feedback encoder connector in the traveling variable frequency motor is loose. Countermeasures: Unscrew the solid encoder connector screw at the fan end of the traveling motor. 6.1.8.5 The wire rope loosens after the hook is opened: After the elevator was lowered into place, the hook was opened after the coke tank was placed on the bed, but the wire rope was loose. reason: If the hook opening limit is damaged or not detected, the loose rope alarm device will operate and shut down. Countermeasures: Check and replace the limit or adjust the limit stopper. 6.1.8.6 The coke pot is implanted and the hook is not opened: After the elevator was lowered into place, the coke tank was placed on the bed, but the hook was not opened and the elevator stopped. reason: During the process of coking the coke tank, the deformation of the coke tank or the spreader causes unbalanced load or loose rope chain shutdown. Countermeasures: Cooperate with machinery to adjust the coke tank or spreader, or adjust the load sensor eccentric load alarm value. 6.1.8.7 Failure of the hoist to report center alignment: When the elevator returned to the upper limit of the lifting tower after loading the empty red coke tank, it reported a running failure and failed to center. reason: . Countermeasures: Adjust the travel and centering limits. 6.1.8.8 APS not working: After the electric locomotive sends an instruction to pick up empty tanks or deliver full tanks, the APS does not move, and the APS does not move when manually operated in the central control room. reason: The main circuit switch of the APS control cabinet is tripped or the contactor is damaged. Countermeasures: Check the main circuit of the control cabinet and close the switch ； Replace contactor. 6.1.8.9 APS cannot perform the next action: After APS is clamped or loosened, it cannot proceed to the next step. reason: No signal is detected from one side of the clamping or releasing limit. Countermeasures: Adjust the clamping or unclamping limit position of the oil cylinder to match the clamping position of the electric locomotive. 6.1.9 Ground dust removal system 6.1.9.1 High temperature of hydraulic coupling: The fluid coupling temperature is high. reason: ①Oil temperature is too high. ②Low oil pressure, no circulation. ③Run at low speed for a long time. Countermeasures: ①Check whether the oil cooling water system is normal. ②Check whether the oil pressure is lower than 0.05MPa. If it is too high or too low, adjust it, clean the filter, and check the oil pump and valves. ③Increase the speed to return to normal. 6.1.9.2 Black smoke emitting from dust removal chimney: There was black smoke coming out of the dust removal chimney and holes in the bags. reason: ①Backflush suction is too large. ②The bag is of poor quality and damaged. ③The suction force is too large, causing the system temperature to be high. Countermeasures: ①Adjust backflush pressure. ②Replace with high quality cloth bags. ③Adjust the suction power and open the air mixing valve. 6.1.9.3 The ash humidifier is blocked: The dust removal humidifier outside the dust collector is blocked and the dust cannot be discharged. reason: ①The triangle belt is broken. ②There is foreign matter inside the humidifier format valve. ③The ratio of water to gray is wrong. Countermeasures: ①Replace the V-belt. ②Open the format valve and remove foreign matter. ③Adjust the amount of water added to control the ratio of water to ash. Carry out the correct ash discharge operation according to the operating procedures. 6.1.9.4 The dust removal fan cannot be started: The dust removal fan cannot be started in the central control or on site. reason: ①The high voltage switch is not turned on. ②The fan inlet baffle is not closed in place. ③The hydraulic coupling oil pressure is lower than 0.03MPa. ④The fan motor bearing temperature is higher than 100°C. Countermeasures: ①Contact the high-voltage distribution room and turn on the high-voltage switch. ②Contact the central control room to close the fan inlet baffle in place. ③Check the working condition of the oil pump and adjust the oil pressure. ④If the bearing temperature displayed on the central control does not match the on-site temperature, replace the thermal resistor. 6.1.9.5 The dust removal fan suddenly stops.: The dust removal fan suddenly stopped running during operation. reason: ①High voltage switch tripped. ②The instrument transmitter failed, and the CRT screen in the central control room alarmed, and the alarm was linked to the dust removal fan. ③EI system emergency stop. ④The hydraulic coupling oil pressure suddenly dropped below 0.03MPa. ⑤The fan motor bearing temperature is greater than 100°C. ⑥The vibration of the fan motor is greater than 0.075mm/min. Countermeasures: ①Check for overload. ②Notify the instrument to check and replace the instrument transmitter, and release the chain. ③Check whether there is a sudden failure and handle it. ④Check whether the oil pump is working properly. ⑤Check whether the bearing is working properly. ⑥Sturdy bottom screw to adjust dynamic balance. 6.1.9.6 Dust removal without backflushing: The dust removal pulse solenoid valve does not blow back, and the central control shows that the pressure difference is high. reason: ①The compressed air pressure used for backflushing is not enough (less than 0.03MPa). ②The spring in the solenoid valve is loose, and the diaphragm cannot be reset after backflushing. Countermeasures: ①Adjust the compressed air pressure for backflushing to within the normal range. ②Replace the spring in the solenoid valve. 6.1.9.7 Bucket lift failure phenomenon: During the operation of the dust removal and ash transportation system, it suddenly stopped running, and an alarm of broken bucket chain and a proximity switch alarm appeared in the central control room. reason: ①The iron limit on the bucket lift proximity switch slides down, causing the chain to stop. ②The wear of the plate chain causes the chain to break. ③The motor anchor screws are loose, causing vibration and causing the chain to fall off. Countermeasures: ①Secure the proximity switch limit firmly. ②Regularly check the wear of the plate chain and perform lubrication work. ③Regularly check the tightness of screws everywhere. ④Strengthen daily inspections and patrols, and take preventive measures. 6.1.9.8 Large dust removal pressure difference and large pollution: The central control room displayed an alarm indicating a large dust removal pressure difference. The on-site environment was polluted, and there was thick smoke at the installation site. reason: ①The production team did not fully implement the pressure difference management system. ②The backflush compressed air pressure of each warehouse on site is too high. ③The speed of the dust removal fan is too high. ④The field backflush solenoid valve is not working. Countermeasures: ①Strengthen the inspection management of each team. ②Strictly adjust the backflush compressed air pressure of each warehouse according to the operating procedures. ③Adjust the reasonable speed of the dust removal fan at the high and low positions of the scoop tube. ④Regularly check the working condition of each solenoid valve. If it is found that the solenoid valve is not working and blowing back, it should be adjusted in time. 6.1.9.9 The dust removal fan vibrates heavily: During the operation of the dust removal fan, the rotation speed and vibration exceeded the standard and were greater than the normal operating state range. reason: ①The bearings at both ends are broken. ②The fan impeller is worn. ③The fan bearing seat, fluid coupling base and fluid coupling base are displaced. Countermeasures: ①Replace bearings or bushings. ②Repair the fan impeller and rebalance it. ③Re-align the coupling and tighten the foot bolts. 6.1.10 Loading and discharging the system 6.1.10.1 The signal of the bottom door of loading is sometimes absent.: After the loading device is opened in place, when the coke tank is placed on the loading device to load red coke into the dry quenching furnace, there is no signal to open the bottom door in the central control room. reason: The original design uses the push rod on the coke tank to drive the detection limit downward, which is easily bent and deformed so that it cannot be contacted. Countermeasures: In order to completely solve the problem, it was changed to non-contact magnetic switch limit detection. 6.1.10.2 The opening and closing limits of the loading device reach at the same time: When the elevator reaches the upper limit of the cooling tower, the loading device does not move, but the opening and closing signals of the loading device appear on the screen in the central control room at the same time, causing the coke tank to drop and the coke to be installed on the top of the dry quenching furnace. reason: ①Because the pressure in the pre-storage chamber is too negative, the loading device cannot be opened. ； A large amount of water is sucked into the dry quenching furnace, and H2 suddenly rises ； The chain signal failed. ②The PLC adjustment control card of the instrument failed, causing the inverter to report a fault and two opposite signals to appear at the same time. Countermeasures: ①If the negative pressure in the pre-recommended section increases, the elevator should be stopped immediately, and instrument and electrical personnel should be notified to perform maintenance and find out the cause. ②Strengthen the control of the pre-storage chamber pressure and install an actual opening signal on the installed track. 6.1.10.3 Rotary seal valve failure phenomenon: When the coke discharge system was in operation, a rotary seal valve failure was suddenly reported on the central control room screen, and the coke discharge system automatically stopped operating. reason: ①Rotary seal valve overload alarm. ②There are foreign objects (such as lining plates, ironware, etc.) in the rotary seal valve, which affect the rotation. ③The steering gear bearing is broken and the motor thermal protection is activated. ④The sealing strips of the sealing chambers on both sides have fallen off. Countermeasures: ①Inform the electrician to eliminate the load alarm in the electrical control cabinet. ②Open the upper access manhole of the rotary seal valve and remove foreign objects (bring a CO alarm and air respirator). ③Replace the steering gear bearing, check the motor, and re-close the switch. ④Open the observation ports on both sides and take out the seals (bring the CO alarm and air respirator). ⑤According to the progress of on-site treatment, gradually reduce the circulating air volume, and notify the thermal power plant to control the power generation based on steam pressure. When the situation is serious, ask superiors for instructions and notify the thermal power plant to unwind. 6.1.10.4 Automatic greasing failure phenomenon: While the coke discharge was running, the central control room reported an automatic greasing failure, and the on-site automatic greasing stopped working. reason: ①The oil level is lower than the normal oil level line. ②The dispenser is clogged. ③The reversing valve does not work. ④Air has entered the oil pump. Countermeasures: ①Replenish lubricating grease. ②Clean the dispenser. ③Repair and replace the reversing valve. ④Open the oil pump to bleed the air. 6.1.10.5 The coke discharge temperature is not controlled: The central control room showed that the coke discharge temperature was higher than the normal coke discharge temperature, the T3 and T4 temperatures increased significantly, and red coke discharge could be seen on the monitor and on site, damaging the coke transport belt. reason: ①The air-to-material ratio is unreasonable and too much air is introduced, so that the coke cannot be fully cooled. ②The air intake ratio between the central and peripheral air ducts was not adjusted properly, resulting in local coke not being cooled. ③The coke falls at an uneven speed in the dry quenching furnace, resulting in large temperature deviations at T3 and T4. In places with high temperatures, the coke falls too fast and cannot be fully cooled. ④Failure to control the storage capacity and coke discharge amount resulted in excessive coke discharge and the coke was discharged before cooling. Countermeasures: ①Reasonably use the air-to-material ratio, control the T6 temperature, and reduce the introduction of air. ②Fully consider the deviation phenomenon that occurs when the coke falls in the dry quenching furnace, and reasonably distribute the ratio of central and peripheral air inlet so that the coke can be fully cooled. ③Control the temperature difference between T3 and T4, and install the adjusting rod reasonably to make the coke drop rate even. ④Strengthen learning of operating procedures * , control the inventory quantity in advance and adjust the coke discharge amount so that the coke can be fully cooled in the cooling chamber. 6.1.10.6 The coke exhaust system cannot be started: The focus exhaust system cannot be started in the central control room. reason: ①Slab gates are not centrally located. ②A belt deviation alarm occurs. ③A device is overloaded. ④PLC has no output. ⑤The signal to a device is lost. Countermeasures: ①Switch operating mode to central position. ②Cancel the deviation alarm. ③Check the motor insulation and perform overload reset. ④Check or replace the PLC output module. ⑤Check line signal or forced signal. 6.1.11 Others 6.1.11.1 1DC ash discharge clogging phenomenon: The 1DC ash discharge valve does not discharge ash, the high alarm in the central control room never disappears, and the on-site ash discharge valve has no temperature. reason: ①There is foreign matter inside the ash discharge valve. ②The triple water cooling jacket is leaking. ③The motor reducer and bearings are broken. Countermeasures: ①Remove the format valve and clean the foreign matter inside. ②Repair triple water cooling jacket. ③Replace or repair motor reducer or bearings. 6.1.11.2 1DC emergency relief valve failure. Phenomenon: The central control room shows that the 1DC emergency release signal is half open and half closed, and the scene is open. reason: ①The valve block counterweight is too large and exceeds the design requirements. ②The limit switch is broken. Countermeasures: ①Remove some weights. ②Adjust and replace the limit switch. 6.1.11.3 The lower part of the 1DC iron plate is burning red: You can clearly see the iron plate being burned red at the scene. reason: ①There is a gap at the flange connection, and air is sucked in and burned inside. ②Internal refractory material falls off. Countermeasures: ①All flange joints are filled with asbestos and sealed with glue. ②Repair interior refractory materials. ③Add a nitrogen pipe to the interior for cooling. 6.1.11.4 2DC blocking phenomenon: The H2 alarm in the central control room does not disappear, and the 2DC outlet pressure is too low. reason: ①2DC ash discharge pipe design is unreasonable and ash discharge is not smooth. ②Water seeps into large particles and the top of 2DC, causing the coke powder to adhere. ③The material level meter display is distorted and the location is unreasonable. Countermeasures: ①Renovate the ash discharge pipe. ②Take measures to prevent rain and water from entering 2DC. ③Calibrate the material level meter and install it in a reasonable position. 6.1.11.5 Leakage phenomenon of heat pipe heat exchanger valve: It can be clearly seen at the scene that water and steam are leaking from the leakage point. reason: ①The flange gasket used in the heat pipe heat exchanger does not meet the specifications and is easily damaged. ②The water system valves after regular repairs and annual repairs are used without pressure. Countermeasures: ①Replace asbestos mats with sensible ones. ②Strengthen daily inspection and maintenance. ③Water system valves that have undergone regular repairs or annual repairs must be compressed before they can be used. This post was last edited by kaisl1314 on 2008-1-17 16:28 ]

Let’s add some operating points for “annual maintenance of dry coke quenching”: 1. Before shutting down the furnace for dry coke quenching for annual maintenance, technical preparations must be made before the shutdown, and the temperature and pressure curves before shutdown must be formulated to prepare the tools required for annual maintenance, and the shutdown plan must be strictly implemented. Preparations before shutting down the furnace: (1) All tools and materials required for cooling are ready. (2) Prepare and become familiar with the annual cooling curve and record sheet. (3) Prepare portable gas detectors and mercury thermometers. (4) Have low-voltage safety lighting ready. (5) Prepare hand hammers, wrenches, pipe wrenches, crowbars and other tools and related safety protection supplies. (6) Check that the expansion indicators everywhere in the boiler are intact and have clear scales. (7) Study seriously * Cooling plan, operating points and precautions. (8) Store enough dry-quenched coke in the coke warehouse to be used when starting the operation. 2. The following operations should be carried out 8 hours before the shutdown (1) After receiving the shutdown notice from the leader, close the main steam cut-off valve and the bypass valve, and stop the external medium-pressure steam supply. (2) After the main steam cut-off valve and bypass valve are closed, open the trap between the main steam cut-off valve and the turbine inlet main valve. (3) The main body of CDQ starts the load reduction operation, that is, gradually reduces the circulating air volume, and reduces the material level in the CDQ furnace to the "0" material level before the planned shutdown time. (4) During the process of reducing the load, pay attention to the following matters: ①Contact the coke oven section in time to load coke to avoid affecting coke production due to delayed contact. ②The load reduction should be carried out slowly within 8 hours, and the coke discharge volume and circulating air volume should not be significantly increased or decreased. ③When reducing the load, first reduce the coke discharge volume and then reduce the circulating air volume, and keep the CDQ stove position below 80t. ④Inform the desalted water station in a timely manner to pay attention to the water volume and maintain the water level of the pure water tank to avoid pure water overflow. ⑤Pay attention to the control of the boiler system (including deaerator and boiler body system), and use manual control when automatic control cannot be performed. (5) Operation requirements during the cooling period ① Temperature control shall be carried out according to the annual cooling curve, and the data of each part shall be recorded once every hour. ②The temperature reduction is based on T5 and is recorded at the corresponding position of the curve every hour. When deviations occur, adjustments must be made in time. ③Cooling plan 1000℃～450℃ 17℃/h 32 hours required ； 450℃～200℃ 11.5℃/h Required time 22 hours ； 200℃～50℃ 4.8℃/h Required time 31 hours ； ④During the cooling and coke discharge process, the main operator carefully monitors the coke discharge temperature to ensure that the coke discharge temperature is below 200°C. ⑤Cooling end mark a. Temperature T5 and the temperature near each manhole reach 50℃. b. Test the circulating gas taken from the sampling hole at the top of the primary dust collector to meet the following indicators to be qualified. Serial number project standard 1 CO ≤50ppm 2 H2S ≤10ppm 3 O2 ≥18%

Contents on maintenance, operation, etc. in "Dry Coke Quenching Technology" http://bbs.hcbbs.com/thread-85789-1-1.html