(22e) Tutorial - Measuring Hydrocarbon Liquid Levels In Highly Dynamic Petroleum Processes

Measuring liquid levels in highly dynamic processes can be very challenging.  Rapid level changes, changing liquid densities, boiling liquids, and interface fluids can combine to make it difficult to get an accurate and/or stable measurement.  This presentation will discuss several of these difficult applications and the solutions found using the various measurement abilities of the guided wave radar.  We will outline best practices for the mechanical installation and the level instrument and explore how to best set up the measurement in order to improve loop tuning.

In some challenging applications, initial liquid levels were changing so rapidly that the level transmitters could not track the changes in real time.  Also, level measurements were not believable since liquid densities were also changing.  The loops could not be properly tuned because of the volatility of the level measurements, which in turn caused liquids to boil and levels to be unstable.  The units were frequently tripping due to high or low alarms, and the plant could only be operated in manual. 

Using the full capabilities of the guided wave radar allowed accurate stable level measurements in a variety of highly dynamic applications.  Using probe-end-projection, damping rates, and using other advanced gage settings we were able to stabilize boiling liquid level measurements, which allowed proper loop tuning to stabilize the process.    The plant now operates without upsets or trips.  The end result was stable process control with very little process variation.