Does the ethylene cracking furnace need to have purge air flowing through it continuously after coking is completed?
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Are there any experts in ethylene cracking? After the cracking furnace has gone through coking, does the air used for cleaning the coke need to be blown continuously? If the furnace is shut down for an extended period (10–20 days), how can cleanliness and dryness inside the furnace tubes be ensured?
After the coking process is completed, if necessary, coke-cleaning air can be introduced to bring the system to a hot standby state. In cases where the furnace is shut down for an extended period, when the COT drops to 220°C, coke-cleaning air should be fed in to blow out any water remaining in the furnace tubes. Once the furnace temperature returns to room temperature, the coke-cleaning air supply should be stopped and the main coke-cleaning valve closed. Finally, nitrogen should be supplied from the DS system to maintain pressure, thereby achieving drying and cleaning of the furnace.
After the burning is complete, the coke-burning air is withdrawn, and the amount of steam available for thermal standby in the pyrolyzer is adjusted so that the pyrolyzer reaches a thermal standby state.
After the burning is complete, there is only one criterion to determine whether it is operational or not: whether it is necessary to cool down to the point where the dilution steam can be stopped. To remove the diluted steam, it is necessary to ventilate and purge the furnace tubes