Capacitance point level detection in liquid naphthalene
Full detection with high process compatibility in chemical plant operation
The measurement technology a chemical plant was looking for in his liquid naphthalene tanks has to deal with different temperatures, varying DK values and viscosity. In order to meet these conditions in practice quickly and reliably with a clever solution, the capacitive rod probes of the RFnivo® series from UWT were implemented.
Changing process temperatures and caking on the sensor boom
In the liquid state, naphthalene is an aggressive substance that quickly corrodes common materials. If it becomes firmer as it cools down, it tends to become heavily attached. For the individual tanks with liquid naphthalene, the system operator therefore needed reliable and robust level monitoring, which can be flexibly adapted to the fluctuating ambient conditions. The chemical manufacturer has several storage tanks that are electrically heated to maintain the melting point of the naphthalene.
There is a process pressure of approx. 0.8 bar (11.6 psi). The DK value fluctuates between 1.6 and 2.0. Each tank was equipped with ainstalled on the overflow line for full notification to ensure reliable protection against overfilling of the containers. When the material is removed, the temperature drops very quickly and cause caking on the sensor boom. Over flow line being there at a height of 1700mm, the installed RF probes work within this over flow line under constantly changing process temperatures (max. up to 80°C (176°F). The "Active Shield" technology integrated as standard in the RF probe ensures that the measurement result is not influenced in the long term by the buildup on the probe.