Robin Redmond

Your product looks very good!
I was curious if the product you are currently offering on sale is endowed with this new proprietary coating,

And does
this new coating cut down on the heat transfer?

Thanks for the advice, and I agree and will try to champher the corners where the collection ring joins the exit chamber. Also, the slow short burns to acclimate the system and keeping it somewhat accessible for future changes is smart. I was just given a gallon of paste-like refractory mortar and may try to "paint" the exposed surfaces of the concrete in the collection ring with it. Thanks for all the thoughtful ideas!

It is. I was under the impression that the hot gases were cooling down by the time it had reached the bottom of the barrel on the exterior of the heat riser. The rest of the rocket stove is fire brick with refractory mortar on a floor of firebrick held off the concrete floor by regular bricks with vermiculite insulation between them. This concrete was poured to be the platform for the barrel to sit on, so the only concrete that is touched by the gases is within that canyon of a collection ring before being exited out the central exit chamber. Also, I am planning on cooling the barrel with copper water coils around the outside of the barrel to heat an (open) water tank sitting on top of the heat mass. So, what do you think? Should I try to destroy the concrete platform?

Satamax Antone wrote:http://donkey32.proboards.com/thread/1406/calculating-ring-circumference-projection-gap

Ok I figured out, using the minimum 1.5 suggested at the post you linked to, my 8" diameter system would need a 3" gap at the top of the barrel. I had only planned for 2 " so I will have to adjust the height of the barrel for that.

As for my "sunken" collection ring, it is nominally a 1-1/2" gap, 2/3s of the way around the barrel, at the top, which is what you can see in the picture, but the cavity widens to 3-1/2" at the bottom, which is 6" below the top of the collection ring. And then the two sides of the collection channel dump into the central chamber which is 6-1/2" wide and 7-1/2" tall, before transitioning to an 8" diameter stovepipe and the first clean out.
This sketch is a side view of the situation (cast in concrete...)

Also the channels widen a bit at the top from 1-1/2" to 2-1/2" as the approach the central chamber.

hi and thanks for the suggestions Max and Glenn.

i am a little puzzled by the descriptions, ie: "ring projection 3" off the ground"
And I wonder what you mean Glenn about the 10x8 reducer

That last post didn't manage to attach the photo which had the caption "exit end of the rocket stove currently"
Maybe this will work (just now learning how to use this iPad...)

Sorry Max,
No I don't for this. I intended to run this out to a T just under the eaves and then run it vertically maybe 4' to 10' stopping a few feet from the roof overhang and sheltered by it.

Well that didn't come out as planned! Oh well...

Thanks Max. I only have space for 4 half bells, which would still entail at least 5, 90 degree bends. Is there a known limit to 90 degree bends for an 8" diameter system? My available space for all this (within the insulated perimeter wall) is 57" by 91" and the inlet pipe will be coming from near one corner and the outlet pipe needs to be centered on the opposite end of the mass from the rocket stove.
/\
Like this: |
|
_______________
|. |
|. |
|. |
|. |__
|._____________|. |
/
/
||||||||O]----/

i am trying to re-consider the possibility of using the half-bell method, but before i give up on the flue design, i was wondering if anyone could tell me the maximum number of 90° bends i can put in without stalling the velocity of the draft? i currently have 10 including the vent shifting to a vertical exit. approximately 32' of run with 10' of that outside under the deck.