As summer winds down here in the Northern hemisphere, many manufacturers and producers must contend with the effects of falling ambient temperatures on their production processes. For some level measurements, pressure diaphragms, wet legs, and any liquid line can suffer damage when process fluids solidify and expand, potentially causing unplanned unit or plant shutdowns. For example, in last year’s big freeze event in Texas, this condition caused some outages with electrical power producers.
Heat tracing is the most common and straightforward technology for processes subjected to freezing conditions to prevent freezing. It can also be unreliable and expensive to maintain. I caught up with Emerson’s John Butler about this challenge. He explained that another challenge with heat tracing is that it can be a time-consuming round of manual inspections with dozens of lines to check. These inspections can significantly affect operational bandwidth and create risk for personnel due to exposure.
John highlighted an alternative approach using guided wave radar with dynamic vapor compensation. The Rosemount 5300 Level Transmitter – Guided Wave Radar with Dynamic Vapor Compensation does not require wet legs, does not need re-calibration, and provides stable level indication during start-up, shutdown, and when loads unexpectedly fluctuate.
He shared a story of one Texas power producer who wanted to learn more about this guided wave radar with dynamic vapor compensation right after the 2021 big freeze. They weren’t ready to swap out all the saturated steam level measurements but wanted to try out the technology first on a single level measurement. After giving it a chance to prove itself over many months, they are working on converting over more of their saturated steam applications.
John explained that this is a common approach for many manufacturers and producers. Since guided wave radar technology requires planning and outage time to install, John typically performs a walkdown of the facility to ensure everything is planned and ready to execute when the time is right. He and other Emerson level measurement specialists provide a free trial of the Rosemount 5300 over 90 days to prove out the application of this technology.
Dynamic Vapor Compensation provides a more reliable solution to prevent impulse lines from freezing, eliminate the need for time-consuming manual inspection rounds and reduce the risk of an unplanned outage. John noted that guided wave radar technology is immune to changes in specific gravity. It, however, does require compensation for dielectric changes in the vapor space in saturated steam applications. Dynamic Vapor Compensation does this automatically and in real-time. Here’s a quick 45-second video, Dynamic Vapor Compensation Technology – Measurement in Changes in Vapor Space Dielectric, showing how it works.
It works by using a target at a fixed distance. Knowing where the reflector pulse should be without any vapor, the distance between the target and the apparent reflector point is calculated. The level measurements are always correct, even during start-up and shutdown, providing constant, reliable measurements up to pressures of 2900 psi (345 bar) and temperatures of 752 °F (400 °C). This technology’s robust process seal design has multiple layers of protection, each resisting the maximum temperature and pressure—increasing reliability and preventing leakage, which is vital for safety.
The Rosemount 5300 guided wave radar level transmitter is a good fit for safety applications requiring SIL/SIL2 ratings. These include high-pressure saturated steam applications in power and industrial steam systems for boiler drums, steam separators, deaerators, and high-pressure feed water heaters, to name a few examples.
Visit the Rosemount 5300 page on Emerson.com for more on the Dynamic Vapor Compensation technology and how it is suited not only for these high-pressure saturated steam applications but also for other challenging level measurements on liquids, slurries, and solids. You can also connect with Emerson level measurement experts by visiting the Emerson.com Level Measurement page’s “Talk to an Expert” link.