rocket stove /mass heater with two drums

Hey all,
I'm thinking of building a rocket stove, something similar to a rocket mass heater.
Originally I thought I could use it as an alternative heat source for distilling ethanol.
For my set up if I use electricity, I'll need an heating element of about 2500w for the initial heating up of the boiler. After that I'll need to reduce the heat for the completion of the run.
I have read a lot (also here) about rocket mass heaters and I thought I can build something that would have two plates for higher and lower temperature. I thought one drum would be using the heat riser heat and one using the exhaust heat. Thought about using 6" pipe.
That's my plan. Tell me what you think if I'm understanding the theory corectly.

Looks good. Your diagram seems to show a second heat riser, but you don't need that.
The second drum is essentially a bell, so no burning should be taking place.

Hey William thanks!
Started reading about bell design now. I think it's exactly what I wanted. Maybe even make three for different temps..
Do you know what would be the cooking temperatures of the plates or better yet the BTU or watt?

Couldn't actually find nothing like that over here or googling. anybody have some direction on that?
Thanks a bunch !
What if I make something like that?

Look at batchrocket.eu for information about bells, as well as batch box core technology.

A bell will not have its inlet going up like a riser, but simply entering at the bottom of the cavity.

Matt Walker has a trick for controlling the heat for cooking.
The barrel has a hole in the top, with a sheet metal "damper" controlling how much if the hot gssses can directly touch the cooking vessel.

Thanks William, can you direct me to that?