Improving PM Collection of EPA Other Test Method (OTM) 36 Precutter


  • Joshua Udvardy University of Florida



air pollution control, particulate matter, computational fluid dynamics


The Environmental Protection Agency (EPA) regulates the amount of particulate matter (PM) emitted by different industrial processes to protect human health and the environment. EPA Test Method 5 is the standard method to determine PM emissions from stationary sources. However, moisture present in emission sources can yield overestimated PM concentrations when using EPA Method 5. Alternatively, EPA Other Test Method (OTM) 36 regulates the method used for determining the concentration of PM2.5 emissions, which are particles with a diameter of less than 2.5 micrometers, from moisture-saturated stationary source gas streams. The EPA has found that the OTM 36 sampling train measures lower PM concentrations than actual concentrations in the emission source. This is because the sampling train’s precutter nozzle, which is the first instrument of a sampling train placed into an emission source, collects particles at smaller sizes than intended, preventing these particles from being measured by the sampling train. The purpose of this research is to create a new precutter nozzle design that allows the PM sampling train to more accurately measure PM to reflect actual concentrations in emission sources tested by OTM 36. By using computational fluid dynamics (CFD) simulations in ANSYS Fluent program, the collection efficiency of different dimensions of the new precutter nozzle was calculated to choose the best design that more accurately collects PM. Based on this objective, a precutter nozzle with a 7-degree half-cone angle and 3-cm throat length was chosen as the most viable design.

Author Biography

Joshua Udvardy, University of Florida

I am a student at the Univeristy of Florida with a major in environmental engineering.


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