For refiners with delayed coking units, maximizing coke drum life is a primary focus. Many factors influence the life expectancy of coke drums including cycle times, crude slates, method of steam stripping and quenching, as well as which method is utilized to feed the drum.
Unlike traditional centered bottom-feed entry, today’s side-feed configurations create coke bed channeling primarily against one wall of the coke drum. This channeling causes accelerated thermal expansion and contraction on one side of the drum which can result in an increase in drum warping, bulging, and through-wall cracks as well as decrease the fatigue life of the drum skirt and cone. Side wall channeling also heats and cools from the outside-in, creating a potential environment for hot-spots and top head blowouts.
This presentation will examine the current options including single side feed, dual side feed and DeltaValve’s retractable center feed for introducing feed into coke drums utilizing automated unheading. The center feed offers significant benefits over all other drum feed systems. The center feed is currently installed in a number of cokers and operational feedback will be presented together with a refinery representative.