LumaSense’s Pulsar range aids sulphur recovery via continuous, instantaneous temperature measurement
Hydrogen sulphide (H2S) is nasty stuff. At all temperatures, it is corrosive to carbon steel and most engineering alloys and must be removed from finished petroleum products. To do so, the Claus Process takes place in a sulphur recovery unit (SRU) where H2S is converted into sulphur through thermal and catalytic treatment, before being used in fertilizers or as sulphuric acid in industrial chemical processes.
That process requires very accurate temperature control, particularly in the reaction furnace, to prevent damage to the refractory at high temperatures and ammonium salt from plugging the converters at low temperatures. Given the high temperatures and corrosive nature of the process, this is a challenge for temperature instrumentation.
Other installations which use reaction furnaces to incinerate waste gases such as ammonia or hydrocarbons must also maintain specific temperatures to assure their destruction. Advanced processes, such as O2 enrichment, normally require even higher temperatures and closer monitoring.
Finger on the PULSAR
The E2T PULSAR range from LumaSense Technologies is uniquely designed to measure two wavelengths for continuous and instantaneous measurement of refractory temperature (RT), gas temperature (GT) and integrated temperature (FF) in the vessel, away from the heat, vibration and corrosive gases of the furnace. Its custom mounting hardware also allows for visual inspection of combustion processes, refractory cure-out and preventative maintenance while the vessel is fully operational.
Using two wavelengths makes it possible to apply a compensation calculation – the Flame Measurement Algorithm (FMA) – to remove the variable effects of flame transparency on the separate measurements. This FMA program takes measurements from both the gas and refractory readings and compensates for changing flame transparency in real-time, removing the inherent measurement errors of typical infrared thermometers and providing an accurate result.
Process monitoring efficiency during sulphur recovery has been improved considerably over the product’s lifespan, through the Pulsar II and III and now the current generation E2T Pulsar 4. The latest model offers both simultaneous gas and refractory temperature measurement using a single thermometer installation, with data made available through separate 4-20mA or digital outputs.
An even greater advantage is that the Pulsar 4 requires little-to-no-maintenance and eliminates the need to perform field calibrations when operating in FMA mode.
Change of HART
Most recently, Pulsar 4 has been made fully compatible with the Highway Addressable Remote Transducer (HART) Protocol. This is the global standard for sending and receiving digital information across analogue wires between smart devices and control or monitoring systems.
HART is a bi-directional communication protocol that provides data access between intelligent field instruments and host systems. This includes any software application from technician’s hand-held device to a plant’s process control, asset management, or other any system using a control platform, ensuring operators have access to vital process information at any time.
That instant access to real-time information offers plant managers a major safety advantage in the event of any change in temperature. Pulsar 4 can inform users of the exact changes or, using HART, issue a signal for temperature alarms or shutdown procedures, all within milliseconds.