dean, do you have any clogging issue recirculating through the therminator when sanitizing? how do you manage hops going through the plate chiller?
The keg kettle has a false bottom and I usually use whole hops in combination with the pellets and it sets up a nice filter bed so not a lot of hop sludge goes through the chiller. I also use nylon paint strainer bags for large pellet hop loads. In many years I have never had an issue with getting the plate chillers clean enough.
I backflush well with tap water in both directions after use and that seems to be fine. Sometimes when I have time I recirculate hot PBW and always get some debris and green color, but nothing major enough to be of concern. I have never had a clogging issue.
To sanitize I start recirculating wort 15 minutes before the end of the boil as best I can and it gets the whole setup above 180f in all places. Even if there was residuals in the chillers nothing will be alive in there :-)
I'm playing with a canister filter from Brewer's Hardware to eliminate the need for the false bottom and plan on whirlpooling alone to control the debris with my new kettle (20gal from Stout Tanks). Unfortunately I have only been able to get the filter to work after the pump and not right out of the kettle so far, so not yet optimum.