| 摘要 |
<p>1349776 Fractional distillation UNIVERSAL OIL PRODUCTS CO 9 July 1971 [10 July 1970] 32280/71 Heading B1B [Also in Division C5] A multi-component feedstock is distilled through a fractionating column (24) divided into two zones (26, 27) by passing it into the upper zone (26), withdrawing a first liquid fraction from the column at a point (28) between the two zones, passing this first liquid fraction through a reboiler (30) and back to the lower zone (27), stripping the reboiled liquid in the lower zone to produce a first vapour fraction and a second liquid fraction, passing the first vapour fraction and vapour from the reboiler into the upper zone (26), where it contacts the feed, to yield a second vapour fraction, and recovering the second liquid and second vapour fractions. The process is particularly suited to the distillation of feeds in which the heavy ends are thermally unstable, e.g. cracked oils. As shown, a vacuum gas oil is fed by line 10 with a hydrogen from line 11 to a cracker 12, water from line 14 is added to the effluent, which is passed to the heat-exchanger 15 and separator 17. In the separator, it separates into three phases: gas, an aqueous phase and hydrocarbon liquid which is passed through heat-exchanger 22 to the still at 24. This comprises the two zones referred to above, and a rectification column 25 with reflex. The stripping medium is steam, admitted at 39.</p> |
