Auxiliary combustion chamber temperature rise

The primary air flow should be reduced by 2%–4%; butterfly valves generally have a high leakage rate. The secondary air flow should be set at 50%. After ignition, the temperature should be increased gradually, making sure that the furnace temperature does not exceed 950 degrees and the temperature of the distribution tubes does not exceed 450 degrees. Adjust the amounts of primary and secondary air as well as the gas flow, following the specified temperature increase curve carefully. Also, pay attention to the sliding valves – ensure they function properly and that there are no blockages in the drainage systems. If there are any errors, please point them out.

1. Direct the gas to the high point of F-101 for evacuation, keeping the gas pressure at ≤0.4 Mpa; ensure that the oxygen content is ≤1.0 V%. Stop the evacuation process once this condition is met. Before ignition, supply loosening air as well as backflow air for the instruments. Use steam to loosen various nozzles, and introduce unpurified air into the pre-lift ring pipeline as a form of protection. 2. Open the baffles of the auxiliary combustion chamber to 1/3; maintain a ratio of primary air to secondary air of 1:5. It is strictly prohibited to close the primary air valve completely. When the gas burner will not ignite, immediately shut off the gas valve and blow air at it for more than 5 minutes to prevent an excessive accumulation of gas in the furnace, which could lead to an explosion during ignition. 3. After ignition, open the louvers and increase the air volume once; adjust the opening degrees of the gas valve as well as the primary and secondary air valves according to the temperature rise curve. Throughout this process, the furnace temperature should remain at ≤950°C, while the temperature at the lower part of the distribution ducts should be ≤550°C℃ ； Pay attention to the flame condition; if the gas supply or air supply is interrupted, the flame should be extinguished immediately, and ignition should be resumed according to the procedures once normal conditions are restored. 4. Adjust the double-acting slide valve, single-acting slide valve, and top vent of the settler appropriately; open the bottom vent of the lift pipe as well as the vent of the raw catalyst inclined tube. Also, open the large oil-gas line vent and the drain line, so that both units can heat up evenly in accordance with the heating curve. 5. During the heating process, shake each slide valve once every hour to prevent it from getting stuck, and regularly check the thermal expansion of the expansion joint. 6. When the temperature of both devices rises to 300 degrees, the unpurified air is switched back to steam; when the temperature reaches 350 degrees, the system undergoes thermal tightening. 7. After the external heat exchanger has reached a constant temperature of 350°C, close the downward valve of the external heat exchanger and increase the amount of air used for fluidization in it. Once the external heat exchanger’s temperature drops below 150°C, water is supplied to its steam drum, and a pump is started to establish a water circulation system.

Additional note: Loosen before the main air flow sweeps in, and use reverse airflow to prevent debris from entering； After ignition, pay attention to adjusting the combustion condition to prevent backburning ； Pre-feeding water for waste heat boiler ； Regularly check the expansion conditions of both devices; do not limit inspections only to the expansion joints ； Be careful to prevent overheating at the main air nozzle, and pay attention to monitoring the axial and radial temperature distributions ； Those with stop valves should be kept from being closed completely to prevent accidental damage

Generally, butterfly valves have a high leakage rate. During ignition, the primary air butterfly valve is usually closed completely.

Everyone should follow the suggestions from the third floor; they are quite correct: lol

What was said on the third floor is pretty much similar to our factory’s operating procedures

I would like to ask how to identify secondary combustion and how to prevent it!