Rocket stove heated steam water distillery

Hey everyone. I was reading this forum for a while and I think its about time for a post of my own.

So, i want to build a rocket stove driven water steam distil for Patchouli. I made a schematic drawing of my Idea.

Basic Idea:
The rocket stove has two inputs. It can be fueled with Patchouli waste (which one gets from each distillation cyclus) or with wood (or both). Right now the Idea is to build it out of steel and use a clay and wood mixture to isolate the heat riser. I think that should work fine. The heat goes into the distillation where it is going through a double pass fire tube (if anyone has knowledge about boilers (what materials to use, how to determine the dimensions, number and position of the tubes, please let me know)).

So i have a couple of questions:
- Does it make sense to use a rocket stove for a steam generator? Normally fireboxes are inside the steam generator, in order to get as much heat transfered to the water as possible. But, if I build the rocket stove inside the steam generator, i think its going to be too large. Especially if i have to isolate the heat riser. Or am I missing something? Does it make sense to build a Rocket stove fueled boiler at all? Am I making up for the heat loss, because the fire is outside of the Boiler, with fuel efficiency?
- Is it a good idea to have 2 openings for fuels in line with each other? My thinking is, that the Patchouli will often be used not fully dry. So having it behind the wood will help a complete combustion. But, am I running into the problem, that the hot air wants to exit through the wood-entry?

I would love to hear some thoughts. I am right now building a prototype for the rocket stove to see if the whole patchouli and wood thing is feasible.

Cheers everyone,
Bene

Try something like this:
https://permies.com/t/43160/Rocket-Stove-Maple-Syrup-Evaporator

Add a lid and a copper line to divert the steam.
Dry your Patchouli waste on the lid before adding it to the wood fuel.

Well, we are talking 400 Kg of Patchouli. So I don't know if the design. You linked to is feasible 😂

Is building a rocket stove out of Iron gonna be a problem with regards to melting it?

Hi Bene,
It sounds like an interesting project.
I was wondering if you had seen this post where he used 2 rocket stoves to boil 160 Liters of water for a distiller.

http://donkey32.proboards.com/thread/1694/rocket-stove-large-essential-distiller

Yes, I have seen that. But I don't really want to have two stoves. It makes everything asymetric if only one is operated and operating two at once seems to be an unnecessary hassle. I tried the two feeder in a row. It works, but it's not stable. It needs tending. So I changed it to having 2 feeders at a 90 degree angle. Works better. But now I have to work out how I deal with the amount of Ash that Patchouli produces.

I attached the images for both designs. Patchouli burns like crazy. I guess its because of the oil in there.

But as I said, it produces a lot of Ash. So now I am thinking of having the wood feeder below the Patchouli feeder and somehow divert the ash in between the two feeders. So if anyone has input on burning loose, ash producing fuel in rocket stoves. I am happy to get input.

Cheers from Indonesia