Zirconia in tubular heating furnaces
Thread Content
This post was last edited by linweihua6 on 2011-11-2 at 19:47. Guys, I know the purpose of installing zirconia in the flue of tubular heating furnaces, but why is zirconia also installed at the junction between the convection chamber and the radiant section?
1. Is it for comparison, to see if there is secondary combustion?
Reply to 2# haijiang417: Please explain in detail
There is no secondary combustion! The oxygen content in the two areas is basically the same; secondary combustion! The oxygen content in the upper part is lower than that in the lower part – just my opinion! For reference only! Hehe!
Previously, to measure the oxygen content in the flue gas, oxygen analyzers were installed on the flue after convection. In fact, the quality of combustion depends mainly on the oxygen content in the radiation chamber. There may be air leakage at the door of the elbow box in the convection section; as a result, the oxygen content in the flue gas after convection is not accurate. Therefore, modern oxygen analyzers are generally installed at the radiant ceiling, which allows for a more accurate assessment of the combustion conditions.
We added an air preheater later on. The chimney of the reduced-pressure furnace does not emit any flue gas; instead, the flue gas from this furnace is combined with that from the atmospheric-pressure furnace and exchanged heat in the air preheater. As a result, the flue gas damper of the reduced-pressure furnace remains closed at all times. Due to the temperature difference, a suction force is created, and it is impossible to keep the flue gas damper completely closed; air is drawn into the furnace. Therefore, the oxygen concentration measured at the upper part of the radiation section is lower than that measured in the flue gas, and it is also more accurate