Thanks for the comments.
Bruce, i can't get your e-mail to work on my machine, probably too many odd characters (my fault).
kurt, thank you. That's very interesting. I've got just the regulator to try that on.
The initial drawings are going to be history soon. I feel like i must simplify and go to a system like the ARTI "tank in a tank," if i want a continuos process.
Evidently the telescopic part where there is no seal between tanks cannot produce anearobic bacteria because of the presents of air in this area. It also seems optimum to minimise this area, as it is waste. The ARTI system uses poly tanks. I'm looking at poly trashcans, or ashbins. Larger than buckets, and available cheaply and in many sizes. The bungs are available in ag stores, in the sprayer dept. You can put a bung in any reasonably flat plastic surface.
What i've got presently, i don't want to waste of course. I've got a tighter fit for the inverted bucket in the water, than the present 30gallon ashbin. So the guide and the inverted bucket will be the smaller of two digestors. The larger digestor will incorperate the 30 gallon inverted (it's already plumbed) into a 50 gallon ashbin.
OK, about heat: The easiest thing to heat is air. The most efficient electric thing is the muffin fan. I even have a DC muffin fan i could run on solar charged batteries. So i'm thinking about an insulated airbox around the digestor, and a thermostatically controlled ducted muffin fan. I can duct it to a rooftop solar collector or a methane burning heat exchanger or any source of heat.
For this stuff to flow etc. i'm also looking into mascerating pumps like they have as an option in the RV world. They are DC i think/hope. Borrowing a surplus blender from the kitchen seems like we're back to making batches and burning juice and time. But this is what the critters teeth do. The feed must first be insized, then ground. Did you ever put grass in a blender? i think it would work with some water. My intensions are to feed this grass and distiller's grain. This is what we have. The corn is so high priced today, they couldn't get a bid on pigs today at a nearby salebarn. Recently they were raising hogs for the manure alone. Now it's too expensive to feed the pigs. Thanks again.