Robert H. Kadlec

Limiting factors on steady-state thermal reactor performance

Limiting factors on steady-state thermal reactor performance were investigated using a Chevrolet 350 cu in. engine and a Du Pont model V reactor. Carbon monoxide emissions were a function of the amount of injected air, and optimum CO reduction occurred in the air injection fraction range of 0.15 to 0.4 and produced a reactor centerline temperature of about 1550 F. Aldehydes which were about 50 ppm without air injection rose five-fold with small quantities of injected air; they fell to 20 ppm in the range of air injection where CO and hydrocarbon oxidation was optimized and rose nearly ten-fold to 460 ppm with excessive air injection. Considering the blending of multiple cyclic inputs which characterizes the exhaust reactor problem, failure to approach complete conversion at a high temperature stationary state depended strongly on both the pattern of flow and the number of coalescences occurring per unit of residence frequency. Simulation runs indicated three basic limitations on conversion due to mixing: departure of reactants from the reactor prior to cell-wise mixing due to insufficient micromixing intensity, lack of sufficient backmixing to blend maltimed input of air and exhaust sufficient backmixing to bring a low-temperature exhaust up to reaction temperature irrespective ofmorexa0» injection.«xa0less