Physical and Chemical Characteristics of Particulates in a Diesel Exhaust

Abstract

The particulate phase of emissions from a single-cylinder, four-cycle diesel engine was sampled 4 inches from the exhaust valve by a variety of methods, including oscillating thermal precipitator and membrane filter. The engine was operated and studied at three conditions: idle speed, no load, moderate temperature; intermediate speed, no load, high temperature; and half load, resultant speed and temperature. The particulates were studied to determine their particle size distribution, specific surface, chemical composition, and acidity. Results are expressed in terms of emission per cubic centimeter of fuel and per cubic meter of exhaust. Representative results are particles in the size range 10 to 500 mn projected area diameter and emission concentrations of 50 mg/m^s, 10^T particles/cm³, and 2 square meters of particle surface area per cubic meter of exhaust. Experimental methods and results are discussed in detail.