[TheForge] Strengthening castable refractory

[Ralph E Douglass]

> 
> In the castable forge that I'm still messing with I used Mizzou 3000
> but was interested in reducing its thermal conductivity.  Mizzou has
> a number of 7.4 for thermal conductivity at 2000 degrees and the
> insulating castable (Kastolite 30 LI, for one) has a conductivity of
> 4.4 at the same temperature which I think is quite a bit less but still
> no doubt much greater than an insulating blanket like Durablanket.
> I called a field rep and mentioned that I had heard that people
> make their own insulating refractory by adding perlite and/or
> vermiculite to the Mizzou.  I was surprised that he didn't pooh pooh
> the idea and said that he had heard the same thing and it might be
> worth a try.  Mizzou weighs 140 lbs per cu. ft. and Kastolite weighs
> 90 lbs. per cu. ft. so I just added perlite and vermiculite (I forget the
> proportiions that were recommended to me) until I got about the
> density I wanted (90 lbs per cu. ft).  For all I know both additives
> may just create air space in the mix after the heat gets to them.

Norm,
COuldn'y you use a single layer of a ceramic blanket to go between the
castable and the outer shell, to provide a better thermal insulation. It
seems as if you did this on the upper portion ( assuming a dome) it
would work. 

Ralph
-- 




                                                        
					
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