Interface and multiphase level measurements are mainly applied in refineries and chemical plants, e. g. on separator vessels. Due to the harsh conditions prevailing in such processes, not all technologies are suitable for these, often very critical measurements. Besides high temperatures, pressures, and corrosive measuring materials, the vessel dimensions and possible installations inside also have an influence on the correct functioning of the measurement. Where other measuring methods fail and cannot withstand these extreme conditions, radiometric measuring systems can provide reliable results. Such systems consist of a source that emits radiation and a detector that can detect this radiation. The measurement principle is based on the attenuation of gamma radiation when penetrating materials such as vessels or the vessel’s contents. Berthold’s radiometric measurement systems are used to monitor interfaces or multiple layers in process vessels. Thereby, not only the interfaces between two phases can be localized, but also the measurement of density profiles in more complex processes is possible. In this way, the heights of the different product layers inside the vessel can be mapped and so the characteristics of a transition phase, e.g. emulsion can be monitored.
Localization of clearly formed interfaces between two product layers can be done by simple measuring arrangements, which depends on factors such as vessel geometry or accuracy requirements. Typical applications for such interface measurements are storage tanks, settling tanks, or separators with clear interfaces. For the measurement of more than two phases or of interfaces that are not clearly defined a more complex measurement system is needed. Depending on the process, a transition phase changing in height or only very small differences in density of the individual phases must be expected, also build-up on the vessel walls or installations inside the vessel are not uncommon in separation processes. With Berthold’s multiphase level measurement system EmulsionSENS, separating layers are reliable monitored and the dependent process can thus be optimally controlled. This system consists of several density measurements installed at different heights with detectors mounted on the vessel outside and sources inserted in a dip pipe to create a density profile of the vessel contents. In addition to the measured density values, the levels of the individual phases can also be outputted as required. Depending on requirements, EmulsionSENS is therefore available in two different arrangements (aligned and staggered). Typical applications for a multiphase level measurement are desalter, hydrocracker, FWKO, alkylation units, and any other separators.