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1. How should sudden interruptions in both the fuel oil and fuel gas for the heating furnace be handled? (1) Phenomenon: The furnace temperature and the temperature at the furnace outlet drop sharply. (2) Handling method: Identify the cause and contact the relevant parties to handle it. 2. What are the reasons for black smoke coming from the chimney and what are the solutions? (1) Reasons: ① Burned-through furnace tubes. ②The instrument failed, and the fuel control valve was fully open. ③Gas contains oil. ④The vapor pressure for atomization drops suddenly. ⑤Inappropriate opening degrees of the chimney dampers, primary and secondary air dampers, as well as butterfly valves result in a lack of air, leading to incomplete combustion of the fuel. ⑥The furnace feed rate increased suddenly. (2) Handling method: ① If the furnace tube is burned through and the damage is minor, handle it as a normal shutdown ； In the event of severe burn-through, it shall be treated as an emergency shutdown. ②If instrument control fails, it should be immediately switched to manual control. ③If the gas contains oil, it is necessary to contact the relevant authorities promptly for handling. ④After the pressure of the atomized steam drops, the pressure of the fuel oil in the nozzle should be adjusted to ensure proper atomization of the oil. ⑤Adjust the opening degrees of the chimney dampers, air doors, and butterfly valves according to the combustion conditions. ⑥The amount of increase or decrease must be controlled slowly. 3. How to address uneven furnace temperature? (1) To achieve uniform furnace temperature, it is first necessary to ensure that the feed rates to each section are consistent. (2) The number of burners in each circuit should be the same. (3) Adjust the flow rates and flames of each burner properly. (4) Regularly check and verify whether the readings of each thermocouple are correct. 4. What are the requirements for operating an electrically driven, fixed-rotation soot blower? (1) The steam pressure for soot blowing should be between 0.98 and 1.47 MPa, with the steam temperature being ≤320°C. (2) Soot blowing frequency: ① When the burner primarily uses oil for combustion with gas as a supplementary fuel, it should be blown once every 8 hours. ②When the burner primarily uses gas for combustion with oil as a supplementary fuel, it is purged once per day during the daytime shift. ③If all the burners burn gas instead of oil, blow them once every two days. (3) Regularly apply 30# engine oil to the worm gear reducer of the soot blower, and apply sodium-based grease (ZN～2) to the rolling bearings and rollers. (4) During use, regularly inspect all gaskets; if steam leakage is detected, it should be addressed promptly. (5) Before soot blowing, first open the steam drain valve to release all the condensate, and then open the steam valve. 5. What are the operating steps for the electric fixed-rotation soot blower? (1) Automatic soot blowing: ① Set the “Step” and “Pre-select” buttons to the “Automatic” position. ②Set the knob of the faulty soot blower to the “emergency” position. ③Turn on the power “switch”; the power indicator light should turn on. ④When the “Soot Blower Ready to Operate” button is pressed, the status light should turn on. If it does not light up, press the “Program Reset” button, and the soot blower will start operating. ⑤After it has finished running, wait until there is no sound coming from the electrical cabinet, then press the stop button for \"Soot Blower Ready to Operate\", and finally press the stop button for \"Power\". ⑥After the soot blower has finished operating, the steam valve should be closed promptly. (2) Manual soot blowing: ① Set the “Step” and “Pre-select” buttons to the “Manual” position. ②Set the faulty soot blower to the “emergency” position. ③Turn on the power “switch”; the power indicator light should turn on. ④Press the \"Start Soot Blower\" button to prepare for operation; the status light should turn on. If it does not, press the \"Program Reset\" button, then press the \"Start\" button for each soot blower one by one to initiate soot blowing. ⑤After operation is complete, wait until there is no sound coming from the electrical cabinet, then press the stop button for \"Soot Blower Ready to Operate\", and finally press the stop button for \"Power\". ⑥After the soot blower has finished operating, the steam valve should be closed promptly. 6. What are the steps for a normal shutdown? (1) Upon receiving the order to shut down, before starting the cooling process, calculate the amount of fuel oil on hand and take in additional fuel as needed, so that the inventory of fuel oil after the shutdown is optimal. (2) If gas and fuel oil are burned together, the gas should be shut off in advance, and the pipelines should be properly handled to avoid difficulties in handling after the furnace is shut down. (3) In accordance with the requirements for reducing the flow rate and temperature of the device, gradually shut down the burners. When 1–2 burners remain, open the fuel oil circulation valve; however, care must be taken to ensure that the pressure of the fuel oil in front of the burners is not too low. (4) When the unit is in circulation, the superheated steam is vented. (5) After the fire is completely extinguished, keep steam flowing to the burner to lower the furnace temperature as quickly as possible, and fully open the chimney dampers. (6) If the furnace tubes are not burned, stop the fuel oil circulation and perform a fuel oil purging. (7) When the furnace temperature drops to around 150°C, open the manholes and viewing ports to cool the furnace. 7. What are the steps for an emergency shutdown of the furnace? (1) Shut off the flame. (2) Stop feeding. (3) Blow large amounts of steam into the furnace chamber and furnace tubes, and divert the superheated steam to vent. (4) Open all the chimney dampers fully. (5) Notify the fire department and plant dispatch. 8. What items need to be checked after the heating furnace is shut down? (1) After the heating furnace is shut down, for the furnace tubes that are prone to coking and are equipped with inspection elbows, first remove the plugs from the elbows (do not face the plugs directly), check for coking in the furnace tubes and elbows, and then reinstall the plugs. (2) After the inspection, if there is a large amount of scale, water should be used to clean it away. If there is no scale but coking is severe, install a plug to prepare for burning off the coking. (3) If the convection chamber of the heating furnace is equipped with nail-headed tubes or finned tubes, their dust accumulation should be checked; if the accumulation is severe, steam cleaning or water flushing should be carried out. (4) Check whether the burner, furnace tubes, accessories, furnace walls, lining, etc. are in good condition; any issues found should be addressed promptly. 14. Maintenance of heating furnaces 9. How is the maintenance cycle for heating furnaces determined? The maintenance cycles for heating furnaces can be divided into major repairs and minor repairs, as shown in Table 14-1. Table 14-1 Maintenance cycles for heating furnaces. Heating furnace type: Medium maintenance/month, Major maintenance/month. Prone to coking and severe erosion: Ordinary – 2–4; Moderate – 12–18; Severe – 12–18; Very severe – 24–36. 10. What does the maintenance of heating furnaces include? The maintenance of heating furnaces includes medium repairs and major repairs. The items included in medium repairs and major repairs are as follows. (1) The medium-term maintenance projects mainly include: ① Checking for coking inside the radiation tubes; if coking is present, it must be removed. ② Inspect and record the corrosion and erosion of the furnace tubes, changes in wall thickness, cracks, oxidation and peeling, bubbling, bending, swelling, and other conditions. ③ Inspect and record the wall thickness, corrosion, and erosion of the elbow. ④ Reinforce and expand, or replace the furnace tubes and elbow fittings, and keep proper records. ⑸ Inspect the elbow plug, tightening screw, wedge nut, and the ears of the elbow for cracks, and perform grinding, repair, or replacement as necessary. ⑥ Inspect the linings inside the furnace, flue ducts, chimney, and viewing ports; any issues found should be addressed. ⑦ Inspect the firebox bricks, burner and its pipelines, valves, etc.; any damage must be repaired. ⑧ Check whether there is ash accumulation in the radiation chamber, convection chamber, flue, air preheater, etc.; if there is ash accumulation, it must be cleaned. ⑨ Check the position of the dampers in the flue and air ducts to ensure they rotate smoothly; any issues must be repaired. ⑩ Inspect and repair refractory brick supports, furnace tube hooks, furnace tube pullers, furnace tube positioning tubes, guide tubes, etc. ⑪ Check whether the thermocouples, cobalt oxide, etc. are in good condition; if there are any problems, repair or replace them promptly. ⑫ Check the sealing condition at the elbow box doors, explosion-proof doors, natural ventilation doors, as well as the inlet and outlet areas of the furnace tubes; if the sealing is poor, it must be addressed. 13 Check that the fire extinguishing steam line and emergency venting devices are unobstructed. 14 Inspect and repair the gas flame arrester. (2) Major repair projects mainly include: ① all medium repair projects. ②Inspection and repair of corrosion in the steel plate thickness of the heating furnace’s steel structure and steel chimneys. ③Inspection and repair of the heating furnace foundation and chimney foundation. ④Inspection and repair of the convective section pipe racks and tube sheets. ⑤Painting and anti-corrosion treatment for the furnace body, chimney, furnace frame, platform, ladder, and pipelines. ⑥Inspection of lightning rods and grounding.