Gerald L. Vaneman

Experimental Evaluation of Fibrous Filters for Trapping Diesel-Exhaust Particulates

A test apparatus containing two raw-gas particulate sampling systems was developed to determine accurately the performance of various materials as diesel exhaust particulate filters. This apparatus was used in conjunction with a single-cylinder diesel engine and a series of fibrous filters to quantify experimentally the effects of filter face area, filter thickness, packing density and fiber diameter on filter performance. Time-dependent efficiency measurements made with this system were smooth and consistent for all of the filters tested and correctly reflected the changes made in these key trap parameters. 6 refs.

The Use of Radioisotopic Methods to Characterize Metal Foil Monolith Catalytic Converters

Radioisotopic methods have been applied to nondestructive measurements on experimental automotive catalytic converters. These converters consist of thin corrugated metal foil which supports an alumina coating impregnated with noble metals. A radiogauging system, using gamma radiation from a gadolinium-153 source, was developed to determine the total quantity and distribution of alumina coating applied to the foil substrate. The radiogauging apparatus was also used to provide axial and radial profiles of lead deposited in the catalytic converter when leaded fuel was used. During dynamometer aging, iron-59 was used as a radiotracer in the alumina to monitor the coating attrition as a function of operating time. These studies demonstrate the capability of radiotracer and radiogauging techniques for rapid, nondestructive measurements on prototype catalytic converters during performance testing.