Burner Flame turning Yellow

[som1973]

Hi All,
We are using Ribbon Pipe Burners for baking Tunnel oven, The Burners lit with blue flame in the morning without any problems, but after sometime the Flame turns to yellow.
The ambient( Oven Room temperature) is around 65 deg C (during Oven operation)

The combustion air for the ribbon pipe burners is provided from combustion blower mounted on the oven.

Does Oven room temperature has any affect on combustion ? I know air density decreases with the increase in temperature. How does Air density affects combustion ( Gas/Air Mixture)

We are using LPG as fuel.

Can you please comment/suggest/advice on this issue.

Thanks in Advance.
Som

 

[StoneCold]

Have you tried measuring the composition of the flue gas? Determining excess O2, CO, CO2, NOX etc can be helpful.
Can you take some pictures of the flames? Maybe one early in the morning and one in the afternoon?

Sorry not much of an answer.

Regards
StoneCold

 

[danw2]

Is there some form of pressure regulated ratio control for ratioing air to fuel at different demand (firing) rates?