|
Post by giogee on Nov 15, 2017 11:52:52 GMT -8
Hi guys been reading the threads for a little while now, I'm amazed at how much information is scattered all over the place. and I'm looking to construct my own Batch Rocket very soon.
I have a question about the refractory material to use, I was told that I can buy insulating Castable refractory material which would retain heat for longer.
I'm not too sure how this would effect the stove but would I be right to say that it will help if I use it for the fire box as it would keep it warmer for longer?
Has anybody else tried this and is it worth pursuing?
|
|
|
Post by Orange on Nov 16, 2017 1:59:28 GMT -8
insulating material for the firebox and riser, classsic brick or firebricks for the bell/bench. Mattwalker, BrianK and many others have swithed to this system...
|
|
|
Post by pinhead on Nov 16, 2017 6:25:57 GMT -8
In general, the entire core should be insulated as well as possible.
That means the firebox in addition to the heat riser.
The riser can be made with superwool (ceramic fiber blanket) inside a steel form. I use flue pipe. An 8-inch flue pipe with 1-inch of ceramic fiber blanket produces a 6-inch riser.
Ceramic fiber board is another option for the batch box, though it's a bit expensive.
My batch box is made with hard red brick but wrapped with three inches of mineral wool insulation.
|
|
|
Post by pianomark on Nov 16, 2017 6:56:07 GMT -8
Giogee,
I think you may be confusing heat storage with heat transfer. The reason for insulating the firebox and riser is to minimize heat transfer away from the space, thus concentrating the heat and raising the temp (in the space, during the burn). The retention of heat in these areas (in the castable itself, after the burn) is less important than the resistance of heat transfer away from the burn area during the burn.
Also, the less dense insulating castable will not "retain heat for longer" (than regular castable). Generally, more dense=more heat storage. That's why you want more dense (greater heat storage) materials in the bell or bench, after the burn is complete. And less dense (insulating) materials around the riser and firebox, to concentrate heat and raise temp as high as possible for a clean burn.
The trade off is the insulative stuff is somewhat less abrasion resistant. Probably not a big issue if you can load fuel carefully. And not an issue at all in the riser, the most critical area for complete combustion. Others with more experience will chime in, I'm sure.
Hope this helps....
Mark
|
|
|
Post by giogee on Nov 16, 2017 13:19:40 GMT -8
Hi guys Thank you for the advice and your thoughts, the only issue I have is the insulating material is rated to 1400C (2552f) and the normal is 1600c (2912f)
I'm going to try and source higher rated material but cost for higher rated material increase to much
|
|