Abstract: This disclosure provides methods for decoking tubular passes of crude oil heaters and processed hydrocarbon heaters. The method permits continued operation of an associated crude oil processing unit or a processed hydrocarbon processing unit receiving crude oil or processed hydrocarbons from the heater during the decoking operation. The decoking operation utilizes dry steam to remove coke from passes within the crude oil heater or processed hydrocarbon heater and dry steam to maintain balanced operation of the crude oil processing unit or processed hydrocarbon processing unit.

Abstract: An apparatus and method for improving the longevity of a cooling tube in a fire tube boiler. The apparatus comprises a ferrule inserted within the cooling tube end and an internal overlay, with the ferrule and internal overlay arranged to provide a smooth, continuous, and diverging passage that reduces turbulence for a heated fluid flowing therethrough, thus preventing the overheating of the tube wall in the highly turbulent area. The internal overlay may be a weld overlay of a corrosion-resistant material that is deposited in a band about the inner wall of the cooling tube, the overlay having an annular inner recess receiving the end of the ferrule. The combination of ferrule and internal overlay also reduces the sharp gradient in temperature that is encountered when the heated fluid enters the relatively cool tube end, thus reducing film boiling, reducing cracking of the tube end, and enhancing corrosion resistance.

Abstract: An apparatus for accumulating coke includes a coke drum having an upper head, a lower section, and a generally cylindrical wall having a height parallel to its longitudinal axis and extending between and joined to the upper head and the lower section. The wall includes an upper ring and a lower ring, each of which has a height parallel to the longitudinal axis of the wall which is in a range of zero percent to 25 percent of the height of the wall. The wall also includes an intermediate ring which extends between and is joined to the upper ring, if present, and the lower ring, if present. The intermediate ring has a length which is equal to a cumulative length of the upper ring and the lower ring subtracted from the length of the wall. The intermediate ring is free of joints which extend in a circumferential direction of the wall.

Abstract: A system that reduces worker exposure during coke drum unheading and cutting operations and that reduces risk to workers also provides a capacity increase in that the time a coke drum is not being filled is reduced. This system employs a containment shield that safely permits drainage through the bottom head and contains water and coke avalanches.

Abstract: A method of manufacturing a delayed coker drum as used in a refining process to receive coke feedstock as a hot liquid and in which the coke feedstock is cooled and quenched to produce solid coke, the hot liquid causing the drum to initially expand circumferentially and laterally and upon quenching to shrink due to thermal contraction, the circumferential shrinking serving to crush solidified coke and the lateral shrinking causing interface frictional contact between the solidified coke and the vessel sidewall that must be overcome, inducing high level stresses in the drum, including the steps of selecting a plurality of metal plates configured for assembling the drum, and welding the plates together creating welded seams and in which the metal plates are selected to have metallurgical characteristics and thicknesses such that their elastic limits exceed the stress introduced in the plates during the quenching process and employing welding materials and techniques such that the elastic limits of the welded se

Abstract: A method of controlling the rate of quench of coke in a coke drum to reduce deterioration of the coke drum sidewall in which water is admitted into the coke drum filled with hot coke to cool the coke includes the steps of determining the stress imposed on the coke drum sidewall by means of at least one strain gauge affixed to the sidewall and controlling the rate of admission of water into the coke drum in response to the determined stress so that the rate of water admission keeps the stress below a preselected maximum level.

Abstract: A method and apparatus for determining the presence or absence of a pour point depressant additive in hydrocarbon liquids includes cooling a sample of the liquid at a predetermined cooling rate from a temperature substantially above the cloud point temperature of the sample liquid to a temperature substantially below the cloud point temperature of the sample liquid. The points on the cooling rate curve for the sample at which a deflection of the curve begins and ends is determined and the time interval between the beginning and ending points of the cooling rate curve is computed. This computed time interval between the beginning and ending points is compared to a reference time interval such that if the reference time interval is less than or greater than the computed time interval between the beginning and ending points on the cooling curve, the presence or absence, respectively, of a pour point depressant additive in the sample is determined.