| 摘要 |
1,047,415. Distillation columns, automatic control. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Feb. 23, 1965 [Feb. 25, 1964], No. 7803/65. Heading B1B. In a system for the continuous distillation of a mixture by means of a fractionating column 1 and a condenser 3 for the top product, the valve 13 controlling the discharge of the top product from the system through conduit 5 is adjusted by a signal from a controller 11 which compares the composition of the top product with a set value, and the return of reflux to the column through conduit 4 is controlled by a valve 12 which is automatically adjusted by a signal obtained by summing the output signal of controller 11 and the output signal from a controller 8 which compares the liquid-level in the accumulator 2 for the top product with a set value. For example, the output signal of the adding element 9 will open valve 12 further if the concentration of the desired component in the top product is too low, and also if the liquid-level in accumulator 2 is too high. The influence on the adjustment of the reflux flow of one of the signals, i.e. from controller 11 or controller 8, may be made stronger than that of the other. |
