Also, regarding your electricity phobia -- note that if you want your RIMS or HERMS system to maintain mash temperatures automatically, there's going to be electricity involved, even if it is gas fired. The only way to avoid electrical work altogether is to go without automation.
I currently have a completely manual direct-fired RIMS system and am in the process of upgrading to an automated system. So take my word for it that direct-fire RIMS is a bit of a pain in the ass without automation. You have to babysit the mash and make slight adjustments to the flame to maintain temperature. Get distracted doing something else and you can easily overshoot temps by 10 or 20 degrees -- aack!
Lonnie's brutus 10 design is automated -- here's
that link. But note that in the original design there's the potential for the pilot to get blown out, which creates an extremely dangerous situation if you aren't keeping a close eye on things. So PLEASE check out this
thread also, which uses a gas valve that automatically shuts down gas to the burner if the pilot goes out.
Originally Posted by 12PACFan
What i had envisioned was wort heated in the hlt then pumped over the grain in the mlt, then back to the hlt. Am i way off?
If you're thinking of a copper coil in the HLT, this is starting to sound more like HERMS than RIMS. For direct fire RIMS you just apply heat to the bottom of the MLT. To prevent scorching, you need a full false bottom in the MLT and constant recirculation with a pump.