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Post by shilo on Jul 3, 2015 2:02:02 GMT -8
in the case that the air intake to a firebox go through a vertical tube, the air inside the tube is cool relatively to the hot air inside the firebox (opposite to a regular chimney) so, which tube will give the air more easily, a downdraft tube or a updraft tube?
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Post by satamax on Jul 3, 2015 3:09:54 GMT -8
The tube eventualy might heat up and act as a second chimney. So updraft, from bellow the firebox, or horizontal. The rest i don't like
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Post by shilo on Jul 3, 2015 4:53:07 GMT -8
The tube eventualy might heat up until what? 200C? 300c? in the end of the tube, the outside temp is above 700C! chimney formula
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Post by shilo on Jul 5, 2015 0:13:49 GMT -8
anyone?
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Post by satamax on Jul 5, 2015 2:08:02 GMT -8
Shilo, i know what you are saying.
But i think it's not regarding the inside gases heat, but the outside air The gases in the firebox being 700c° are a long way less dense than the outside air, the ones in the outside air supply might heat to may be 150C°, but they will still be less dnese than outside air. So, if your outside air supply comes from the top, i would be dubious if it works. And furthermore, if the outside air would be taken at the same height as the chimney top, i can't see it working well. Ok, the stack effect will be different with different size tubing, between intake and exhaust, but still i'm not convinced.
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Post by shilo on Jul 5, 2015 2:17:08 GMT -8
my intuition say the same as yours. but the formula not
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Post by shilo on Jul 7, 2015 9:09:44 GMT -8
any more thoughts?
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Post by peterberg on Jul 7, 2015 11:35:03 GMT -8
Of course, there are tricks to get enough air via a downdraft tube. In the case of the batch box, the air in the port has a higher velocity and therefore a lower pressure. This will help, a lot.
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Post by shilo on Jul 7, 2015 12:14:30 GMT -8
yes but my question is which tube will give the air more easily? a downdraft tube or a updraft tube? who is right, my intuition or the formula?
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Post by peterberg on Jul 7, 2015 13:14:35 GMT -8
I didn't look at the formula, but is gravity accounted for? If not, your intuition wins.
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Post by shilo on Jul 7, 2015 14:24:41 GMT -8
9.81
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