New pompeii build with center flue question

[RodO]

I am not sure if I have ever posted before, but have been a member for along time. I have built 6 ovens based upon the FB Pompeii plans.
I am getting ready for my next, and probably my last build. This build will have a 36" cooking floor and I want to tile this oven and am trying to decide upon an efficient way to take the smoke/heat back over the top of the dome to create a center vent, similar to the FB Vesuvio tile oven. In my mind, I am thinking it will involve a home brew cast channel. I am open for suggestions. Also, any knowledge as to cubic inch size of the channel to provide an adequate draw up the flue. Any other ideas would be appreciated. Thank you!

[rsandler]

I don't have any info on this myself, but since no one else has chimed in, I did a little poking around and searching "squirrel tail" or "beaver tail" on the forum turns up some builds that have done this style of flue. I would assume the minimum cross-section is the same as for a straight flue--28in^2 (equivalent to a 6-inch diameter round flue) ought to be sufficient for a 36" diameter oven.