The Periodic Technique for Measuring Convective Transport and Flow Friction Characteristics of Catalytic Reactors

Consistent optimization of low emissions catalyst systems will require appropriate use of alternative substrate geometries. Fundamental heat transfer, mass transfer and friction characteristics provide a solid foundation for evaluating the benefits of these geometries. The purpose of this report is to validate a bench test, based on a previously reported technique, for measuring the fundamental characteristics of catalyst substrates. The sample matrix is subjected to a periodically varying inlet temperature and convective transport properties, reported as Colburn factors, are found by matching the phase shift and amplitude attenuation of the inlet and outlet temperature waves in a finite difference computer program. Flow friction attributes, reported as Fanning friction factors, are found through reduction of measured pressure loss at constant flow rate. Measured Colburn factors and Fanning friction factors for uncoated square and triangular passage monoliths agree closely with theoretical values, validating the technique. Measured results for two coated substrates are also presented.