Ceramic blanket v vermiculite

[smarty]

I have a question about the relative insulating ability of ceramic blanket v vermiculite or other loose fill insulation. The reason for asking is that I have an old cooking stove that normally has vermiculite filling in around the cast iron guts of the thing and the outer casing. They are designed to be thermal storage units that heat up slowly and then hold their heat over a period of time during which time a very low fire is kept burning constantly to keep the heat topped up.

I am playing around with converting one into a rocket stove powered cooker. This requires a different approach to heating the thing up etc. shorter intense burns rather than low continuous operation. To facilitate this and heat the cooker up more quickly I was considering the possibility of dispensing with the vermiculite packing and instead insulate the casing itself with ceramic blanket. I was then going to block off the flue that comes from the top at present and instead empty the flue inside the box of the casing around all the cast iron innards and then out through a flue exiting out the back at the bottom. Essentially what I would be doing is turning the ceramic blanket lined casing into a bell rather than a completely filled box of insulation.

The only thing I can't find out - other than actually building it and seeing - is whether the ceramic blanket say 2" thick will insulate as well as 4 - 5 inches thick of vermiculite. Does anyone have to hand any figures on this comparison?

I guess for comparison's sake the thermal conductivity at about 300 degrees C or something like that.

[Deleted]

Blankets may insulate slightly better.

For comparision

Blanket data for a broad temperature range
www.barteltinsulation.com/pdfs/CERAMICBLANKET.pdf

Vermiculite data is only for low temperatures
www.vermiculite.org/pdf_word/Vermiculite_Data.pdf

[smarty]

Thanks for that Karl. I gather from that that since they are quite close a 2" layer of ceramic blanket is going to be about half as insulating as a 4" layer of vermiculite. Sound about right? or perhaps it is not quite so simple.

[Deleted]

Aside of the insulation the properties of ceramic blankets and vermiculite are very different.
The question is whether the other properties of ceramic blankets are worth the high price.