It sounds to me like the OP is looking for some sort of "Bashguard" as opposed to something like a Chainboard?

I installed a Chainboard on my Xtracycle. My goal was to reduce the amount of crud that my crankset and chain were subjected to. I also made a piece to put on the other side of the bottom bracket, so that for all intents and purposes about 75% of the three chainrings are covered/enclosed, and the chain is covered on top and the right side (back to the V-racks on the Freeradical). I lucked out and the front derailleur fits and works under and inside the Chainboard.

It is still too early to determine whether or not the objective has been accomplished.