Experimental investigation of the effect of the flame holder geometry on flame length and NOx and CO emissions in a non-premixed burnerr

In this paper, the effect of different flame holder geometry on the flame length and NOx and CO emissions in a non-premixed burner is experimentally studied. A non-premixed burner with natural gas fuel and some cylindrical flame holder geometry with fixed outer diameter and different internal diameter and length is used. First, tests are carried out for the flame holders with the internal diameter of 4 and 6 cm and length of 10 cm and then for the flame holders with the length of 10, 15, and 20 cm and the internal diameter of 6 cm. The results show that by increasing the air flow rate, the flame length increases at the fixed-power of the burner and by increasing the power of burner, the flame length increases at the fixed-air flow rate. Moreover, it is indicated that any changes at the length and internal diameter of the flame holder have not effect on the flame length, but there are effective on NOx and CO emission. Increasing the diameter of the flame holder decreases up to 42 percent of NOx and increases up to 40 percent CO.