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Show The ring stabilizers create a wake of hot combustion products in the flow, which continually ignites the incoming jet of reactants. This technique of attaching a flame to a burner falls under the general category of bluff body stabilization and is fundamentally different than the thennal process used to attach traditional rim stabilized flames. Bluff body stabilization is well understood and will not be discussed further [4,5]. TEST PROCEDURES Blowoff limits and flashback limits were detennined for a variety of burner configurations at a variety of reactant flow rates. To detennine the blowofflimit, the burner was brought to steady state conditions near and equivalence ratio of unity. Slowly the fuel flow was reduced until the flame became to lean and blowoff occurred. Flashback limits were detennined in a similar fashion. In this case, the procedure is to start with a flame with an equivalence far away from unity. Slowly the ·fuel and air were adjusted to produce a flame closer to stoichiometric. At low flow rates, as the equivalence ratio approached unity and the burning velocity increased, flashback occurred. In all tests, data from the reactant mass flow meters was recorded directly on a computer based data acquisition system. In order to accurately measure pollutant emissions from the burner, a generic heat exchanger / exhaust gas collection unit was employed. This device is shown in Figure 2. The heat exchanger sits on top of the burner and collects and cools all of the product gas from the burner. The unit is air tight so that no dilution with atmospheric air can occur. The cooled exhaust gas is funneled into a 45 cm long stack from which samples are drawn through two separate probes. Sample' gas is fed to a Cambustion HFR 400 fast flame ionization detector (FFID), a Wilks Miran I variable filter infrared analyzer, and a Horiba CLA-51.QSS chemiluminescent NOx analyzer. In addition, a Snap-On MT3500 Emissions Analyzer was used to supplement CO measurements from the Wilks analyzer at concentrations above 600 PPM. For the NOx and CO measurements, the sample is drawn 5 |