Particle Size Distribution Determination - Particle size distribution is determined using a cascade impactor that utilizes the particles' inertial forces (which are proportional to the particles' mass, i.e., to the cube of the particle diameter) to deposit particles by size on a series of collecting stages. The fraction of total particulate mass collected on each stage is determined gravimetrically. Impactor design and operating parameters are used to compute the range of particle sizes impacted on the individual stages. The particle size used for data interpretation is the aerodynamic diameter, termed D50, meaning 50% of the particles collected on the stage correspond to the cutoff size. Typical particle sizes measured range from 0.3 to 40 microns.
Unburned Carbon Determination - For determining the unburned carbon concentrations, ash samples are collected and burnt in an atmosphere of pure oxygen. The carbon dioxide formed from the combustion process is then absorbed in caustic solution. The amount of oxygen consumed is measured and used to determine the carbon content in the ash. This analysis is particularly useful for quick determination of loss-on-ignition (LOI) on coal-fired burners.
Temperature Measurement - Multiple-point flue gas temperatures are monitored continuously using data acquisition systems. Thirty-channel manual thermocouple readouts are also available for some applications. Data collected are processed and stored in spreadsheet format for analysis.
