| 摘要 |
960,501. Control of fractionating columns. ESSO RESEARCH & ENGINEERING CO. March 14, 1962 [March 30, 1961], No. 9791/62. Heading B1B. In fractional distillation apparatus comprising a fractionating column 11, a condenser 13 for the overhead vapours, and a conduit 15 for the return of part of the condensate to the column as reflux, the pressure in the column is maintained at a predetermined value by pressure-sensitive device 17 which communicates with the interior of the column and regulates the reflux control valve 16. The reflux rate is measured by flow recorder 21. The condenser may be of the air-fin type. The liquid to be fractionated is introduced into the column through conduit 24; and heating steam is supplied to the reboiler 25 through conduit 26. The rate of supply of steam is regulated by control 28 which measures the pressuredrop across a number of trays. The composition of the overhead fraction, which is measured by chromatographic analyser 22, is controlled by flow-rate control 19. Valve 30, for the withdrawal of the bottoms product, is regulated by liquid-level control 29. The fractionator can be used to separate isopentane and butane from mixtures of light hydrocarbons. |
