Combustion modeling acid-alkali

Similar instrumentation to that used on the cross-fired pilot furnace was used. Testing the proposed auxiliary combustion injectors suggested by the acid/alkali modelling demonstrated that significant NOx reduction could be achieved as shown in Figure 13. 

Experience has shown that for a confined flame, sufficient primary air jet momentum is required to create mixing via external recirculation zones. As the acid-alkali model shows, high momentum and, for that matter, intense and perhaps complete mixing, is tantamount to efficient combustion. We discussed in Chapter 4 that, for confined jets, the onset of flame recirculation can be described by the Craya-Curtet... 

Figure 6.10 Acid-alkali modeling of combustion in rotary kilns (a) low burner momentum, (b) high burner momentum.

In order to understand the flow patterns within the combustion chamber to allow selection of suitable Injection points and make initial evaluation of the likely effect, flow modelling was required. Both computational fluid dynamics (CFD) and acid/alkali physical modelling were used. 

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