Model TLG-837-SP -Sulfur Pit Analyzer

• Continuously measures H2S levels using UV-Vis spectrophotometer
• Totally solid-state build with no moving parts — modern design for low maintenance
• Additional software benches for up to 4 chemical analytes
• Ultra-safe fiber optic design with no sample gas inside analyzer unit — world’s safest solution for this application

Sulfur Storage Pit
A sulfur recovery unit (SRU) serves to remove H2S (and other sulfur-containing compounds) from incoming acid gas and convert it into elemental sulfur. A Claus process is the most common method used for an SRU. Sulfur that is removed during the Claus process is condensed and directed into a sulfur storage pit. The liquid elemental sulfur that is produced in the Claus process can contain upwards of 300 ppmw of dissolved H2S.

Over time, the dissolved H2S will off-gas into the headspace of the sulfur storage pit, creating an equilibrium between the gas and the liquid. The H2S that accumulates in the sulfur storage pit must be monitored. H2S has a lower explosive limit of 4% by volume, and can ignite when in contact with mechanical equipment such as pumps or compressors.

DEMISTER Probe
The DEMISTER sampling probe was designed to be lightweight and compact, so it can easily be installed by a single technician. The probe is inserted into a flange on top of the sulfur pit, and continuously cycles sample gas. Ultraviolet light from the spectrometer inside the TLG-837-SP Analyzer travels to the head of the probe through a fiber optic cable, where it interacts with the sample before being returned to the analyzer via a second fiber optic cable. The light being returned to the analyzer is then analyzed via the ultraviolet absorbance measurement technique, and an H2S reading is displayed.

No sample is removed from the probe and brought into the TLG-837-SP Analyzer enclosure. This ensures that there is no risk of sample leaking inside of the analyzer enclosure, which minimizes the risk to plant operators. The DEMISTER Probe conditions the gas sample to remove any trace elemental sulfur vapor which may plug up the probe. This feature minimizes the required maintenance of the probe.