Thanks for the reply Al,
In my post under the heading "my first thought" I explain the insulating of the burn chamber. So you stated you have no problem with Under the riser "encasing a 6” 90’ elbow inside a few inches of fireclay/perlite inside of fire brick. Then continue that heading into a short section of 6” pipe encased in the same two layers of fireclay/perlite and firebrick heading to the feed chamber. The feed chamber will be made using just fire brick. This will be all encased in masonry mass/cobish something or other. "
The wood floor is covered in durrock backer board, then 4" concrete cap block, then there will be a double layer of fire brick under the burn chamber and the the double insulated tube. The heat exchange pipes will be elevated to as close to the center of the core of the mass as I can get it, so at least 12"-14"" off the floor. The photo was a mockup just to show the T clean out which you did not comment on.
Al, you stated: "Heat Riser, while it is possible to make a Heat Riser without any fire brick at all, just Perlite andClay slip, you shouldn't put firebrick on the outside of insulation, there is no job for fire brick other than that of surrounding the fire, for any other job something else will do a better job !
It kind of sounds like your not a fan of the double pipe packed with fire clay perlite method that seams to be one way that has been suggested by Ernie and Erica to use on the Heat riser. (IE heat risers made without using fire brick.) Also, I did not say that the riser was going to be inside firebrick.
To explain the proposed burn tunnel again: there is a square tunnel of fire brick.....inside of it is a 6" tube.....between the tube and the brick, there is a layer of Fire clay and perlite to keep the tube centered, and to maintain the 6" tube shape after the metal has burned out.
As four the questions I was asking
1st. How long should the burn tunnel be from the feed chamber to the heat riser.
2nd. What is the distance from the top of the riser to the surface of the 55gal drum- this will let me know how tall to build the insulated riser.