Many refiners today want to monitor their reactor vessel wall temperatures in order to protect their investment. A variety of obstacles are encountered in this vital application, such as difficult installation/replacement and welding to wall restrictions.
Traditionally, refiners monitored the reactor temperature with a basic weld pad thermocouple or a washer thermocouple. The weld pad cannot be replaced once it fails because welding to the reactor wall is not allowed, and the washer thermocouple is difficult to replace because it is buried under the insulation. In both cases, neither can be installed in a retrofit application.
Daily Thermetrics, the company that developed the patented CatTracker® for reactor profiling, has developed two designs to tackle this critical application:
For new reactors, when welding is permitted, the unique weld pad of the VSS™ Weld-On is welded directly to the reactor wall. A threaded barstock thermowell insert is then attached to the weld pad and will vary depending on the insulation thickness. The sensor probe is then screwed into this thermowell insert, thus allowing for easy sensor replacement in the future without additional welding and with superior reliability and measurement accuracy.
For existing reactors, Daily Thermetrics offers the VSS™ Magnetic. The vessel insulation is pulled away, and this VSS™ Magnetic assembly is then simply placed into position without welding to the vessel. If desired, insulation can be placed back over the VSS™ Magnetic assembly or a new metallic insulation patch can be fabricated to accommodate future changeout of the sensor component of this design.
For more information related to the design and specifications of these and other custom vessel skin sensors, please contact firstname.lastname@example.org or your local Daily Thermetrics' representative.