Abstract: A process for the preparation of lower olefins from a heavy hydrocarbon feedstock by vaporizing said heavy hydrocarbon feedstock with steam in a nozzle wherein a two-phase mixture is passed through a device having a frusto-conically-shaped element which is capable of inducing a gentle swirl pattern to a liquid-containing stream, which device is connected to the feed inlet pipe of the mixing nozzle. This swirl-inducing device effects a 90° bending of the flow direction of the hydrocarbon feedstock while simultaneously effecting a swirl pattern of the liquid part thereof, thereby forcing the liquid against the wall of the feed inlet pipe extending downwardly to the mixing nozzle with such velocity component perpendicular to the tube's longitudinal axis to create an annular flow pattern as the mixture enters the nozzle and the vaporized hydrocarbon feedstock is subjected to a cracking treatment.

Abstract: Apparatus for the vaporization of a heavy hydrocarbon feedstock with steam includes a frusto-conically-shaped element which is capable of inducing a gentle swirl pattern to a liquid-containing stream, which device is connected to the feed inlet pipe of the mixing nozzle. This swirl-inducing device effects a 90° bending of the flow direction of the hydrocarbon feedstock while simultaneously effecting a swirl pattern of the liquid part thereof, thereby forcing the liquid against the wall of the feed inlet pipe extending downwardly to the mixing nozzle with such velocity component perpendicular to the tube's longitudinal axis that an annular flow pattern is re-established.

Abstract: Apparatus for the vaporization of a heavy hydrocarbon feedstock with steam includes a frusto-conically-shaped element which is capable of inducing a gentle swirl pattern to a liquid-containing stream, which device is connected to the feed inlet pipe of the mixing nozzle. This swirl-inducing device effects a 90° bending of the flow direction of the hydrocarbon feedstock while simultaneously effecting a swirl pattern of the liquid part thereof, thereby forcing the liquid against the wall of the feed inlet pipe extending downwardly to the mixing nozzle with such velocity component perpendicular to the tube's longitudinal axis that an annular flow pattern is re-established.

Abstract: Apparatus for the vaporization of a heavy hydrocarbon feedstock with steam includes a frusto-conically-shaped element which is capable of inducing a gentle swirl pattern to a liquid-containing stream, which device is connected to the feed inlet pipe of the mixing nozzle. This swirl-inducing device effects a 90° bending of the flow direction of the hydrocarbon feedstock while simultaneously effecting a swirl pattern of the liquid part thereof, thereby forcing the liquid against the wall of the feed inlet pipe extending downwardly to the mixing nozzle with such velocity component perpendicular to the tube's longitudinal axis that an annular flow pattern is re-established.

Abstract: Producing light olefins from a contaminated liquid hydrocarbon feed by means of thermal cracking of, which process comprises the steps of supplying the feed (6) to the inlet (7) of a membrane unit (1) provided with a polysiloxane membrane (10), and removing from the permeate side (9) a permeate (14) and from the retentate side (8) a retentate (12); supplying the permeate (14) to the inlet of a cracking furnace (2), allowing the permeate to crack in the coils (15, 16) of the cracking furnace (2) in the presence of steam (17) at elevated temperature and removing from the cracking furnace (2) a cracked stream (19) which is enriched in light olefins; quenching (22, 24) the cracked stream; supplying the cooled cracked stream to a fractionation column (3); supplying the retentate (12) to the fractionation column (3); and removing from the fractionation column (3); a gaseous stream (30), a side stream of fuel oil components (45) and a bottom stream (50).