We almost never change the way of cooling and we also use the half-hour soaking during the quenching step. However, the quality of feed alters frequently. Generally, our feed is the bottom product of vacuum distillation units, but sometimes hydrocrack residue is mixed in this feed.
We usually, but not always, experience steam eruption when hydrocrack residue is mixed in and/or the asphaltene content is high.
Is there anything else which can be done to reduce the chance for steam eruption? I mean for example FCC slurry oil mixed in DC feed when asphaltene content is high, or rising the coking temperature at the end of coking phase?
If you have DC feed from more sources then it is worth trying to blend a DC feed which has low asphaltene content?