Coke drum overhead vapor valves are massive affairs. Switching a pair of 20-ft diameter drums may require the manipulation of four 18-in. and four 12-in.…
Author: Jack
Figure 2-5 shows the valves used during the coking cycle. Prior to switching out of a coke drum, the process operators must be sure that…
Turning around a coke drum is a cooperative effort between the process operators and the decoking crew. It is labor intensive and normally accomplished without…
How long should it take to turn a coke drum around? The elapsed time from when one switches out of a full drum until it…
Whether or not increased recycle ratio reduces shot coke formation is dependent on the composition of the incremental recycle. Recycling 950°F-1,000°F coker gas oil will…
Sulfur causes puffing of the calcined needle coke. Increasing the delayed coker recycle ratio by cutting the heavy coker gas oil end point will make…
Needle-grade coke contains no shot coke. Commercial needle coke is typically produced by charging FCCU slurry oil to the delayed coker. All of the components…
The outside surface of shot coke spheres is coated with a layer of needle coke. The coating gives shot coke its polished-surface appearance.
The formation of cross-linked aromatic rings can be reduced by lowering the coke drum pressure, raising the coke drum outlet temperature, improving the vacuum tower…
The yield of precipitated asphaltenes cannot be reduced because the asphaltenes in the coker feed will produce coke regardless of coke drum operating parameters.