SRE- Thanks for the response and welcome to Sulfur Unit! The steam jacketing as you mention is a good place to start troubleshooting. I would like to install wireless trap monitors on my sulfur equipment to detect an immediate loss of trap function rather than having to wait until I have a problem. Unfortuntately, our infrastructure isn’t ready for wireless yet.
The eductors we use are fully steam jacketed, as is the inlet and outlet piping. This leads me to believe the fouling is actually in the eductor nozzle rather than the piping. We still use 70# saturated (or super saturated at times) steam for the motive force. I’ve heard from wiser sources that medium (~150#) pressure superheated steam is recommended for eductors.
One interesting thing our operators discovered was what they call a “Turbo Boost” of the eductor. When performance drops, they would turn off the motive steam for a minute or so and then quickly crank it all the way open. This would help restore some of the lost eductive flow.