Brick Riser

I have seen pictures of brick risers on rocket mass heaters, but I can't find any info on them. I searched but it didn't turn up anything.. I maybe didn't choose the right search terms? Anyway any info on them? They seem the be the most durable of this high temp part.

Thanks I love this site!

Kevin

Kevin : Go to www.rocketstoves.com and download a copy ( $15.oo U.S. ) I. Evans'- great book ' Rocket Mass Heaters', there is no other source of Rocket specific material anywhere else in any language ! Be safe,stay warm, Allen L.

I have it, but while he shows one picture of it, he gives no specifics.


Kevin

Not sure what kind of info your wanting, and I have a question. We are building our first RMH, here you see the start of our Brick Heat Riser! It is a very simple process of legos however we have a question about joining the bricks together. We have read that you shouldnt get Firebrick wet? If we use cob (Clay, Sand, Straw) and put this on the firebrick, that would get the firebricks wet. Wouldnt they crack when we burn a fire in it?

Seeing as how the book/vids dont have enough info for you.
Make a list of specific questions that you would like to be answered. Maybe someone here can give some ideas.
I am going to assume that you want specific info about the firebrick.

At what temp does firebrick falls apart vs the temp of RMH? ?F vs 3000F
What are some come common things that could make my firebrick fail? furnace cement?
What can I do to make it last longer? dont get them wet.
Are there different type of firebrick? etc, etc

Common firebrick will hold up just fine at temps of 1200F. There are firebrick which will take higher temps-these would be for industrial uses, and can be considerably more expensive.

Water is the enemy of firebrick. Get it wet while it's hot, the surface can erode quickly. The steam can get into the nooks and crannies of the brick, forcing the material apart. Also, the sudden shock of splashing the brick can cool it rapidly. The result is called thermal fracturing. One side of the brick is cooled, the other side is hot. These brick have a high alumina and silica content which allows the brick to heat uniformly, but sudden shocks from water cooling can result in one side shrinking while the other side stays hot. Its the sudden contraction that causes the thermal fracturing.