Design of a Diesel Particulate Generator

Diesel particulate generators (DPG) are devices used to generate diesel particulate matter, commonly known as soot, to test diesel particulate filters. A diesel particulate generator would be especially useful at Union College to test aerogels as diesel particulate filters (DPFs). Non-aerogel DPFs have recently been added to many diesel vehicles to help manufacturers meet the ever-changing diesel emission regulations set by the EPA and other international agencies. The problem with these filters is that they are large, costly, detrimental to fuel efficiency, and the material used will sometimes melt at high temperatures. Aerogels are a potential approach to addressing  these problems. Due to their high porosity they can hold just as much, if not more, soot as current filter designs and can withstand high temperatures. These advantageous characteristics could combine to allow for filter designs that are less detrimental to fuel efficiency. In this work, a diesel particulate generator was designed and manufactured to test aerogels as DPFs. The design uses compressed air (at flows of 0 – 3 cubic feet per minute) to blow powdered soot simulants through aerogels. The DPG is capable of holding and testing up to 0.44 in³ (7.2 ml) of aerogel. Furthermore, the design can blow different types of diesel soot simulants (i.e. different carbon based powders) through aerogels at controlled rates yielding consistent testing conditions. Initial testing of aerogels using the DPG has shown that in certain situations aerogels can hold close to 40% of their own weight, and that different types of soot simulants behave significantly differently with regard to capture efficiency.