摘要 |
In a process for thermal cracking of liq. hydrocarbons, the preheated feedstock is fed to the base of a vertical pressurised reactor having a cross-sectional area increasing with distance upwards. Since the prods. are less dense than the reactants, this profiling tends to preserve a constant linear velocity for the process stream; and the angle of the reactor wall with the vertical axis is pref. chosen, between 2 and 15 deg., practically to achieved this. A constant velocity of the process stream reduces back-mixing, and therefore the relative importance of secondary reactions to produce pitch, coke and asphaltenes. These aims are achieved without fitting perforated plates, which interfere with reactor cleaning. |