| 摘要 |
<p>1277616 Automatic level control UNIVERSAL OIL PRODUCTS CO 2 Sept 1969 [11 Sept 1968] 43371/69 Heading G3R [Also in Division C5] In a chemical process a fluid mixture is combined with a gaseous reactant, heated and passed through a conversion zone, separator and fractionation column, signals dependent on the level of unconverted material in the column, the rate of flow of gaseous reactant or separated gas, and the rate of change of such flow, are combined to vary the datum of a signal dependent on the temperature differential across the conversion zone which, in turn, controls the datum of a signal dependent on the temperature of the feed to the conversion zone which finally controls the heating of the feed to the conversion zone. As applied to the hydrocracking of oil to produce naphtha, oil supplied through a conduit 10, Fig.2, is mixed with hydrogen supplied through a conduit 11 and the mixture heated in a furnace 13 before being fed to a reactor 19 containing three catalyst conversion zones 20, 21, 22. Hydrogen is supplied as a quench through conduits 62, 63 to points between the conversion zones and the effluent from the reactor is taken through a conduit 23 to a separator 38 the unconverted hydrogen output of which is added to the hydrogen input through a conduit 56. The remainder of the effluent passes through a conduit 39 to a chamber 40 in which methane, ethane and propane are flashed off through a conduit 41. The remaining effluent finally passes through a conduit 43, via a debutanizer column if desired, to a fractionation column 44 from which naphtha is removed through a conduit 46, gases are removed through a conduit 45, and other unconverted material is re-cycled to the furnace input through a lower conduit 12. To maintain the unconverted material at a desired level at the bottom of the column, a signal from a level detector 47 controls, through lines 48, 52, the set point of control systems having detectors 31, 32, 33 responsive to temperature differentials across the conversion zones, which, in turn, control the set points of controllers having detectois 28, 29 responsive to the temperatures between the conversion zones which control associated quench hydrogen flow control systems 24, 25 and a detector 17 responsive to the temperature of the feed to the reactor which controls the fuel supply to furnace 13 through a conduit 15. To provide an anticipatory effect, a signal from a detector 57 or 42 responsive to the rate of flow of hydrogen input-or flashed off gas, together with a differential term, is added to that from level detector 47 in a summing amplifier 49.</p> |
