Oxygen content in flue gas of heating furnace
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Gentlemen, I would like to ask: if three furnaces share one air preheater, that is, if the flue gases from all three furnaces combine before entering the air preheater to exchange heat with air, and if the oxygen content in the exhaust gases of each furnace is 2%, 3%, and 4% respectively, then, assuming no air leakage or instrument errors, shouldn’t the oxygen content in the flue gases at the exit of the preheater be no higher than 4% and no lower than 2%? Thank you!
It should feel like this! The oxygen content is between 2% and 4%.
This post was last edited by zhai*aoh on 2013-1-3 02:00. The question is strange; there must be something suspicious about this!
No, the oxygen content should be between 2% and 4%. The oxygen content in the mixture of the three streams of smoke should be the weighted average of the oxygen contents of each stream, based on their volume flow rates. The calculation method is as follows: let the volume flow rates of the three streams of smoke be Q1, Q2, and Q3 respectively, with corresponding oxygen contents of 2%, 3%, and 4%. Then the oxygen content in the mixture is (Q1*2 + Q2*3 + Q3*4) / (Q1 + Q2 + Q3), expressed in percentages. In other words, assuming the volumetric flow rates of the three streams of smoke are equal, the oxygen content after mixing should be 3%.
:The friend on Floor D explained things in such a professional manner; great job!