VEGAFLEX 86 delivers precise measured values in crude oil processing

From the point of view of interface measurement, there are a number of challenges here: The composition, and thus also the DK value and density, of the crude oil-water mixture changes depending on where the oil comes from. For example, the density can vary between 820 and 940 kg/m³. This means that the running time of the previously used measuring methods also varied.
Until recently, a level gauging method that works according to the displacement principle was used at this measuring point. Besides the fluctuating density, other factors also affected measurement accuracy: vibration and turbulence. Nevertheless, this measuring system had been in use at the site for many years because there was simply no alternative. A classic interface measuring method just did not deliver the required accuracy. At one point the company tried using a TDR reference sensor from another manufacturer, but it did not work satisfactorily because its compensation range was not large enough.

During the development of the VEGAFLEX Series 80 sensors at that time, the focus was not only on simple instrument selection and guided setup, but also on reliability and measurement certainty. The greatest advantage of the sensor: It delivers exact values regardless of media properties such as density or dielectric constant.
In interface measurement with guided radar, the radar pulses are guided along a cable or rod probe and reflected by the product surface. The measuring probe of the TDR sensor ensures that the signal travels down to the product undisturbed. The series consists of four different instrument types, each of which is tailored to a particular application. VEGAFLEX 86 is often used for high temperatures and high pressure applications, e.g. in distillation columns or in crude oil processing. It has a ceramic insulation and graphite seal in the coupling that can withstand the penetration of steam at a maximum pressure of 400 bar and temperatures up to 450 °C. The spacers in the coaxial probe are also made of ceramic and mechanically stable enough to withstand the vibrations and shocks.
A good solution to the problem of fluctuating dielectric constants has also been developed for this sensor. This probe was originally designed to compensate for the signal propagation time in the steam atmosphere of steam boilers. A test should now provide answers as to whether this also works in the crude oil in a desalinator. Ultimately, the innovative steam compensation ensures higher measuring accuracy. The VEGAFLEX 86 used in Vohburg uses a reference section of 750 mm and has a probe length of 3,950 mm. Incidentally, the reference section for compensating for deviations is the longest one available on the market. The longer this distance, the more accurate the measurement.