(74a) A Propane-Air Micro Jet Premixer

Mezzo Technologies fabricates micro tube heat exchanger panels that provide extremely high rates of heat transfer per unit volume with very little pressure drop penalty. These heat exchanger panels can then be assembled in a variety of ways to meet the needs of a specific application. The performance advantages associated with these panels are the predicted result of decreased channel size. These panels, originally conceived for heat exchanger applications, are now being investigated as mixers and reactors. Mezzo's micro tube heat exchanger panels have been modified slightly, resulting in a premixer for a gas turbine application. Propane gas is ejected from numerous uniformly-spaced holes of diameter 100-200 ?Ým. The array of propane micro jets is injected counterflow into a stream of oncoming air. The air-propane mixture then flows back through the plane of the premixer. Complete mixing is achieved over a very short distance of a couple of centimeters. The premixer was designed, fabricated and tested. The experimental apparatus is described, and test results are provided. Low NOx, high turbulence intensity, and a lean blow blowout limit below 0.5 all indicate that very good mixing was achieved. While more experiments continue to be performed to fully quantify the premixer performance, the initial indication is that the very simple, sturdy design provides excellent mixing in a very compact volume. Finally, additional concepts are introduced that demonstrate methods by which these panels can be assembled to produce reactors and mixers with unique design and, theoretically, excellent performance.