Give me some more information. How you respond to a furnace trip depends on a lot of factors. How long is the furnace down? How long have you been in the coke drum? Did you lose flow into the coke drum? How cold did the coke drum outlet temperature get? All these things factor into the response to a furnace trip. You need to respond differently based on looking at all these factors. The main thing is to try to keep flow into the coke drum on a furnace trip. Upon a furnace trip our control system sweeps the passes with steam into the coke drum. This keeps the channels in the coke bed open. The next thing we would look at is how long has the drum been coking. If it is late in the cycle we would not reintroduce feed, but prepare the drum for decoking as normal. We would put the furnace into bypass, or swing feed into the sister drum if it is available, and then bring up the furnace. If it is in the early/middle of the coking cycle we would look at coke drum outlet temperature as a determining factor as to whether or not to reintroduce feed. A cold drum outlet temperature will create foaming issues with the reintroduction of feed. If we can get the furnace back up before the coke drum outlet temperature gets too cold then we would restart feed at a lower rate, (to extend the coking time) raise our furnace outlet temperatures and finish filling the drum.
Hope this helps,