Steam Line in the Burner

[meyou]

When we replace one existing furnace in the site.
Ther are some steam line with fule gas line at bottom of the furnace.
And in the convection zone also have some steam line inject into the furance.
I just want to know what is the steam used for?
Is the bottom steam line is for pulverize the fuel oil/gas?
And is the top steam to control Nox?

Please advise.


Thanks

 

[quark]

They are called smothering steam lines as far as I know. In case of an uncontrolled fire break out in the furnace the steam is used to extinguish it.

 

[jalvarez]

Furnaces firing a gas fuel or a clean liquid fuel as naphta or diesel oil, will normally encounter little convection section fouling. But the original designer, if he thought (or the spec commanded) that a liquid residual fuel can be fired, it is a possibility that you have sootblowers installed in the convection section. Very occasional now, but common some years ago.
A normal design criteria is/was to install sootblowers for liquid fuels with an ash content greater than 0.01 wt.%.
For the steam you are looking in the floor of your furnace, you may simple detect if this is for atomizing liquid fuels, because you will have an individual line for each burner. (If you have liquid fuel or dual type burners).
If the steam is introduced in the firebox, quark is right, they are for fire smothering/extinction.
Also you may find smothering steam in the return bends boxes, in the convection section. This steam is installed there for probable leaks in the return bend plugs, if your old furnace have them.
Have a safe day
J.Alvarez

 

[skippy2]

The steam line to the bottom of the firebox apart from being used for smothering, can also be used to purge the firebox before light off of the first burner (ensures no fuel present, provided sufficient time is allowed for purging)