Production of Gasoline & Co
After crude oil has been desalinated and cleaned, it is fractionated into its constituent parts in distillation columns. Under temperatures up to 752°F (400°C), the mainly gaseous crude oil is transported to the distillation column and then condensed in intermediate stages at varying temperatures. The lower the boiling point of the product, the higher the condensate ascends. For optimum operation of the column, accurate temperature, pressure and level measurement is of paramount importance.
Level Measurement with the VEGAPULS 66
In the past, displacer systems in bypass tubes have been used for level measurement in distillation columns. This maintenance intensive principle is being replaced more and more with non-contact radar sensors. Existing bypass tubes can usually be used for the measurement, so no mechanical modifications are necessary. The high product temperatures in the lower part of the column require special sensor types. The VEGAPULS 66 is an optimum solution for this application because of its operating temperature of up to 752°F (400°C) and its pressure capability of up to 2320 psig (160 bar).
Column Pressure with the VEGABAR 51
An important value to monitor in the distillation process is the top pressure at the upper end of the column. Depending on the type of distillation, the systems operate under vacuum or extremely high pressures. The VEGABAR 51 pressure transmitter with its wide temperature range is particularly suited for this application - even extreme temperature fluctuations during the start-up phase in the column do not cause it any problems. The sensor version with isolator can even be implemented in temperatures up to 752°F (400°C).
Level Measurement with the VEGAFLEX 86 in a Bypass Tube
As an alternative to non-contact radar sensors, the level can be measured with a guided wave radar sensor in a bypass tube. In this measuring principle, microwaves are guided down a rod. The bypass tube together with the rod measuring probe form a coaxial system. Even products with a dielectric constant less than 1.7 can be reliably measured with this system. As an added benefit, the connecting tubes between vessel and bypass do not cause false echoes. The VEGAFLEX 86 is the ideal solution for operating temperatures up to 842°F (450°C).
