Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Gregory J Thompson


As the emissions standards placed on diesel engine exhaust become more stringent, the use of exhaust aftertreatment devices such as diesel particulate filters has become a more attractive means to meet those standards. During the use of these filters some of the particulate captured, usually ash, begins to restrict the flow through the filter. This increases the backpressure in the exhaust system and requires routine cleaning maintenance. This study reviewed engine technology used to reduce particulate emissions and investigated the effects of off-line cleaning of diesel particulate filters using compressed air and water flowing in the reverse direction of the exhaust flow. The resulting effects of these cleaning procedures were examined by measuring the weight lost and the pressure drop across the filters at varying air flow rates. Both the differential pressure and weight loss indicated that most of the particulate was removed during the initial stages of compressed air cleaning. A maximum of 92% of the total filter weight was removed from a single filter with a maximum decrease of 65% of the differential pressure across the filter. Flowing water in the reverse direction was found to be one of the most effective options in cleaning these filters, but many filters have matting materials that are damaged when exposed to water. Compressed air blown in the reverse direction for a thirty minute time period is recommended with a subsequent twenty minute water cleaning, if water is not restricted by the manufacturer.