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Unless there is a specific question that would benefit this mailing
list, without seeing and knowing the intricacies of particular
commercial burners I can't, won't and don't see the point of making
any comment on those, however, I'd like to respond to a couple of
the more general issues...<br>
<br>
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<div><span
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<snip> </o:p> If a natural gas flame is not
pre-mixed it needs more time and space to burn well. For
a given number of Joules it needs more volume. This can
be demonstrated (be careful!) by closing the premixing
hole in a gas stove burner and watching what happens.
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<br>
Comparing the premixed flame length to a nonpremixed flame length is
like comparing chalk-and-cheese. The laminar flame thickness is
surprisingly similar, but not the total flame length. However, the
initial discussion came from the comparison of methane and propane,
so in terms of flame length, I'll steal an example from the second
edition of Steve Turns' wonderful textbook...<br>
Examples 13.1 and 13.2 do the exact task of comparing flame length
for the same burner geometry and heat input. Paraphrasing the
question: "Estimate the flame length of a propane jet flame in air
at ambient conditions, with a fuel mass flow-rate of 3.66 g/s and a
jet exit diameter of 6.17mm. Compare the flame length of a methane
flame for the same heat release and jet exit diameter."<br>
The answer: Propane flame length = 1.94m, Methane flame length =
1.71m<br>
This is only one example, but demonstrates that the volumetric
heating capacity of the fuel does not proportionally affect the
flame length.
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<p class="MsoNormal"><span
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Is there a common device burning natural gas that does
not use a premixed flame? <snip><br>
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<br>
Basically any furnace firing natural gas (e.g. cement plant, glass
plant, steel plant,....)<br>
<br>
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