I am thinking about using vitrified clay pipes instead of gallon drums for both inside drum and outside drum of the rocket mass heater: https://en.wikipedia.org/wiki/Vitrified_clay_pipe What are your thoughts?
I would like to improve durability as gallon drum and high temperature/oxidation will cause me to have to change the gallon drum from time to time.
With the vitrified clay pipe I hope it will simply last.
Vitrified clay pipes may be capable of withstanding high heat, but they are not going to be capable of absorbing fast temperature changes, or probably uneven heating, without cracking. The outer steel drum will not be exposed to the major heating, and perhaps due to the oxygen-poor atmosphere inside, are known to last a long time (decades) without deteriorating. The internal chimney, or heat riser, needs to have the lowest mass and best insulation you can get. Vitrified clay fails on both counts. You want a semi-porous material that will hold its shape and not deteriorate with extreme heating. Insulating firebrick is ideal but expensive and may be hard to get in remote areas. Ceramic fiber is ideal but may be fragile (or may be quite durable), also expensive and can be hard to get. Perlite or vermiculite mixed with just enough fireclay to hold it together, and formed into a cylindrical tube, is cheap and fairly easy to get, and very effective. A metal stovepipe of the right diameter as the outer form for this tube will also last a long time, as it is protected from the corrosive interior atmosphere by the lining.
Thanks guys for the quick reply.
I will then stick to the gallon drum.
Location: Southern alps, on the French side of the french /italian border 5000ft elevation
posted 2 years ago
For the insulation holder, you have plenty of options. And for the "barrel" you have several more. Like fuel tanks from trucks, home heating fuel tanks, stainless wine containers. I havve made my workshop one with home heating fuel tanks.