Like Combustion Engineers says "If it mixes it burns", contrary to that it would be "CO forms if it doen't mixes properly"....
well that's just quote, now let's be a little practical, Why CO at kiln inlet? 2% is exorbitantly high!!
it is generally absorved that during maintenance shut down all the "newbies" test their skills on real equipments,
1) since it is uniflow burner, Check Static pressure and flow at primary air fan and compare it with previous Normal runs...Insufficient momentum could be one reason?
2) Is their any Carbon (Sticky coal dust) deposition onto the burner tip?
3) is your burner pipe (inside) absolutely hassle free?
Burner tip position wouldn't really contribute much to incomplete combustion unless it is erratically positioned? which i don't think is the case here.
Hope this would help
Hussaini
I would suggest you to
1. measure the burners flow at the air channels. Compare them with those before shutdown. (You can find any damage under the concrete or something else happened that couldn't be seen)
2. look at the burner tip. It could be damaged somehow or wrong mounted?
3. compare the kiln inlet static pressure? any change? (any blockages that can result in higher velocities?)
I hope you've fixed problem.
Regards,