fire box opening

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Smoke Blower
Original poster
Dec 21, 2016
Hello all
I had a question about the fire box opening to the cc. I used feldons calculator tank is is 20 by 46 air compressor my fire box is 18h 16w 18l the calculator says the fb opening to Cc ..opening size round is 7.27 and diameter is 10.5 .my question is the 7.27 is that just one single 7" hole or is that the height of the half circle and the 10" the length of the half circle or do I go up 5" and make that half of the recommended 10" diameter
FB opening should be about 58 sq. in....  (20 x 20 x 0.7854 x 0.004 = 58) .... I would make the segment height, line ED, 5" high... that gives you and opening of 61 sq. in.  ...  more is better...  make the opening at the end of the RF plate the same and under the RF plate the same...

Make the opening the same as the green area...  account for material thickness also... 

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For rv smoker build is my fb opening supposed 1 1/2 times does that mean instead of the segment line being 5" to the top it's should be 7 1/2 is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

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