Experimental study on CH* chemiluminescence characteristics of impinging flames in an opposed multi‐burner gasifier

The bandpass filtered images of impinging flames in an opposed multi‐burner (OMB) gasifier was visualized by a CCD camera combined with a high temperature endoscope. A filtering and image processing method by use of three bandpass filters was applied to subtract soot and CO2* contributions in the CH* band and obtain the CH* chemiluminescence of impinging flames. The results show that a clear reaction core is generated in the impinging zone of four‐burner impinging flames. The size of the reaction core is affected by the O/C equivalence ratio ([O/C]e) and the impingement effect is relatively stronger at lower [O/C]e. The flame lift‐off length in the gasifier is jointly controlled by the syngas concentration and the diesel atomization effect. The impingement effect shortens the flame lift‐off length. The relationship between the syngas concentration and the maximum CH* intensity makes it possible to evaluate the syngas concentration from CH* intensity.