GB388114A - Improvements in or relating to the production of hydrocarbons of low boiling point by the thermal decomposition of hydrocarbon oils - Google Patents

Abstract

<PICT:0388114/III/1> Oils are cracked in the vapour phase, and the vapours freed by condensation at least from constituents boiling above 400 DEG C. are recycled with the vapours to be cracked. Vapours obtained by p evaporating gas oil in a vessel F are passed through a cracking vessel A heated to 600 DEG C. and the vapours are cooled in a washer B by spraying with crude oil introduced through a line H so that constituents boiling above 360 DEG C. are condensed. The residual vapours are in part dephlegmated and condensed to give a final product in vessels C, D while the remainder are recirculated by a blower E through a separator G to the vessel A. Complete separation of heavy constituents may be obtained by spraying part of the reflux collected in the dephlegmator C into the blower F, the remainder of the reflux together with the liquids collecting in the vessels B, G being led to the vessel F. Condensation of heavy constituents in the vessel B may be aided by electrical precipitation. Several evaporators maintained at different temperatures may be connected in parallel and worked cyclically.