OCR Text |
Show ) / overall, the effect of oxygen enrichment via the primary combustion chamber to minimize the emissions from transient puffs does not seem to be dramatic over the experimental region examined here. Indeed, it can be detrimental when the effects of temperature are included. To illustrate that the effect of increasing kiln temperature can be detrimental to transient emissions, Figure 8 presents filter weight data from each of the second and third experiment sets (Tables II and Ill) versus measured kiln exit temperature. Data from experiments taken at constant stoichiometric ratio (SR=2.0) (Figure 8a) and constant post flame oxygen flow (F02=14.4 m3/hr, 510 scfh) (Figure 8b) are presented. These data, relating to low oxygen flow/enrichment (open symbols) and high oxygen flow/enrichment (solid symbols), have been corrected for dilution by normalization to a standard total flow of 113 m3/hr (4000 sCfh). Data taken at similar kiln loads are connected. The data show fair correlation between filter weight and measured kiln exit temperature, and indicate a trend of increasing particulate emissions with increasing temperature over the experimental range examined here. The data may indicate some slight reduction in particulate emissions due to oxygen enrichment at similar kiln loads, as shown by the dotted lines on Figure 8. However, if the oxygen enrichment causes a dramatic increase in the kiln temperature, particulate emissions are actually increased. This is also illustrated in Figure 8 by comparison of all open or solid symbols. 15 |