Delayed Coker - Coking Safety & Communications

Fired heaters/furnaces are designed to refine various types of hydrocarbons (oils and gasoline's) and to separate these liquids (feedstock) into specific products. This process involves the heating of extensive lengths of heaters/furnace tubes. Throughout this process the interior of the tubes becomes congested with baked on coke, restricting the flow rates and insulating the feedstock so more heat is required externally on the heater/furnace tubes to maintain charge temperatures. Through time coke build up may severely restrict flow rates or plug the heater/furnace tubing completely. Restrictions in the tubing reduce a heater's revenue generating capability, in a short period of time.

Recently a new technological process of cleaning out the tubes of refinery heater/furnaces has emerged. Since its inception I.C.E. has diligently analyzed the advancement of this closed loop pigging technology.

Our industry leading team have learned from experience and detailed an analysis of the specific quality benefits of the pigging process.

For years steam-air decoking has been referred to as the best method and the "norm" of coke removal. Steam-air decoking involves firing the heater/furnace to high temperatures and blasting steam air through the tubes to thermally crack the coke deposits. This process must be carefully monitored to assure that the tubes do not exceed heating specification thresholds. However, to try and remove stubborn deposits the recommend heat threshold is commonly exceeded, by steam-air decoking endangering the integrity of the tubes and therefore the risk of safety hazards in the refinery increases. The outcome of the steam-air decoke is very difficult to monitor and coke deposits are left on the tube walls and inorganic deposits can not be burned off.

Therefore steam-air decoking only acts as a temporary solution or a "band-aid". The tube temperatures are difficult to monitor as temperatures can vary greatly from one location to another during the steam-air decoke procedure. Temperatures often exceed 1300 degrees Fahrenheit; this is hot enough to cause carbon infusion into the tube wall, making it brittle and dangerous. This heat can also cause the tube walls to permanently stretch or warp. This will increase tube size ID and leave sections of the tube wall dangerously thin. Depending on the placement of thermal reading devices, it may be impossible to detect danger areas. Most steam-air decokes will take an average of 72 to 100 hours (oil to oil) and involve many refinery personnel to monitor the procedure.

Fired Heaters Decoking Tubing