Measuring Level of Highly Concentrated Sulfuric Acid

SITRANS LR250

For fairly obvious reasons a US chemical company was having a very difficult time finding a process level instrument for a tank containing 93% sulfuric acid. Not many materials can stand up to the corrosive nature of even dilute sulfuric acid, not to mention the concentrated form. Level sensors with special wetted parts would only last a few months and the transmitters would have to be replaced on a regular basis. Downtime was very high and the maintenance was very costly.

Recommendation

SIEMENS recommended the SITRANS LR250 Radar PVDF for the application. The SITRANS LR250 with threaded PVDF antenna is a 2-wire, 25 GHz pulse radar level transmitter for continuous monitoring of liquids and slurries in storage and process vessels including corrosives or aggressive materials.

After having the unit installed for a few months, the unit was taken out and inspected. Signal profiles were taken and compared to the signal profiles when the unit was first installed. These profiles demonstrated strong performance by the SITRANS LR250 in that the acid level was being tracked reliably and the inspection of the PVDF encapsulated horn antenna showed no compatibility issues.

Conclusion

The Siemens SITRANS LR250 transmitter with its PVDF encapsulated horn antenna has proven to be the proper instrument for sulfuric acid applications. It provides a lower cost alternative to other instruments requiring exotic and expensive metal alloys. After being in operation for over three years, it has demonstrated a significantly increased life span.

Contact Ives Equipment for more information on the Siemens SITRANS LR250.

Download the full SIEMENS case study here.