Fired heaters afterburn

If you try to operate a furnace, fired heater, or boiler with too little combustion air to starve the burners of oxygen to smother or bog down the firebox, then you will likely cause afterburn or secondary combustion in the stack, you will not be able to operate on automatic temperature control, and may even destroy the equipment altogether. 

But if the fins have just become brittle enough to break off by hand, the problem is afterburn. The fins have simply been burned up by secondary ignition. While oxidation is a form of corrosion, we have discussed this problem in our chapter concerning the flue-gas side of fired heaters. (See Chap. 29.)... 

Afterburn Re-ignition of flue gas in the convective section of a fired heater. 

When the combustion air was cut back this time, fire started to come out of the stack. Now Operator A was forced to admit that they would have to increase the combustion air again. The problem they then faced was that the amount of draft in the heater seemed to be less than before and they were not quite able to reestablish the same airflow. The reason for the restricted airflow was that they had caused afterburn in the... 

Industrial furnaces that do not show color, that is, in which the temperature is below 1200 F (650 C), are commonly called ovens in North America. However, the dividing line between ovens and furnaces is not sharp, for example, coke ovens operate at temperatures above 2200 F (1478 C). In Europe, many furnaces are termed ovens. In the ceramic industry, furnaces are called kilns. In the petrochem and CPI (chemical process industries), furnaces may be termed heaters, kilns, afterburners, incinerators, or destructors. The furnace of a boiler is its firebox or combustion chamber, or a fire-tube boiler s Morrison tube. ... 

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