Tai Piazza and Greg Tischler, VEGA Americas, USA, present two case studies to emphasise the importance of being able to isolate instrumentation on a valve and still receive reliable level measurements.
H
igh-value processes are found everywhere in the chemical industry. Massive storage vessels hold volatile yet precious chemicals, and base ingredients move through complex continuous processes to create all-important chemical components. In both scenarios – and everywhere in between – the ability to isolate instrumentation on a valve and still receive accurate and reliable level measurements is key to safe, continued operation. Two chemical plants with very different processes on opposite sides of the US were dealing with similar level measurement dilemmas: unreliable, high-maintenance instrumentation in processes that are costly to take offline. Both facilities consequently employed the VEGAPULS 64. They mounted the radar sensor on complex process connections, and it did not interfere with their measurement, due to the sensor’s 80 GHz technology.
Measuring in tight spaces High frequency radars for level measurements have several benefits, but when it comes to mounting on more complex process connections such as ball valves and knife gate valves, a highly-focused signal and narrow beam angle are important. A radar’s beam angle is determined by two factors: antenna size and transmission frequency. Both factors are inversely proportional to the radar beam. A larger antenna or a higher frequency will emit a tighter signal. An 80 GHz radar sensor with a 3 in. antenna has a beam angle of less than 4°, enabling the sensor to emit an uninterrupted signal past the many reflective surfaces and tight spaces found within a ball valve. Additionally, when more of the radar signal’s energy reaches the product surface below, the radar antenna will receive a stronger return signal to provide a more reliable measurement – even when it is measuring a product with poor reflective qualities. 33 Summer 2021 3
