Search Results

Performance and durability tests were conducted on ceramic fiber-wound diesel particulate filters in the exhaust stream of both laboratory and in-service diesel engines. Metal-based additives were used to facilitate filter regeneration. Copper, iron and cerium additives were evaluated in laboratory tests for their effect on particulate filter performance and durability during tests totaling more than 3500 hours. Field data obtained on in-service vehicles validated and supplemented laboratory results. Effects of the additive on engine performance and durability are also presented.

This paper summarizes the investigative work done to evaluate the effects of diesel substrate mounting materials on substrate surface temperatures and external shell surface temperatures. For the work completed, a test set-up and protocol was established, test results were obtained for different materials, a representative thermal model was developed, and the experimental test results were compared to the thermal model results. A stationary diesel engine incorporating secondary fuel injection for active regeneration was employed. The base test exhaust emission control systems consisted of a DOC + uncatalyzed DPF configuration. An appropriate data acquisition and thermocouple map was developed to monitor the exhaust system temperature conditions. The test cycle employed consisted of a soot loading segment, a standard filter regeneration segment, and a transient regeneration segment.

Five areas of test methods and equipment as used at The 3M Company Diesel Filter Products Laboratory are discussed. These include: 1. Diesel particulate sampling, 2. Data acquisition and process control, 3. Durability evaluation, 4. Exhaust gas flow rate measurement, and 5. Engine test benches. These methods and equipment, among others, enable performance and durability evaluation of diesel particulate traps.

The Cummins A3.4-125 (rated 93 kW at 3600 rpm) has been developed to meet 1991 US and California light-heavy duty emission standards, replacing the Cummins 6AT3.4 (formerly Onan L634T-A). Compliance with the stringent particulate standard has been achieved by redesigning the combustion chamber, a systematic oil control program, and charge air cooling. The Ricardo Comet combustion chamber was modified to a downstream glowplug configuration. Oil control efforts addressed all sources of oil derived particulate. With charge air cooling, NOx emissions were reduced while improving fuel economy, torque output, altitude capability, and engine durability. THE CUMMINS A3.4-125 is an evolutionary development of the 1988-90 6AT3.4 engine. The development was driven primarily by 1991 US and California light-heavy duty emission standards, but also was the result of a policy of continuous product improvement. The Cummins A Series diesel engine family was conceived as the Onan L Series (1*).