Condesing Plumes

The ETA Emission Reaction Analyzer (ERA) has been developed to answer questions about reacting and condensing plumes. With the ETA ERA, sources can determine the temperature, relative humidity, and ambient mixing ratios that cause their emissions to condense and/or react to form a plume of visible aerosols.

The ETA ERA begins by removing a gas stream from the stack or duct. This sample is ported via a heat traced sample line (containing a thermocouple) to the Plume Simulation Chamber. The sample first enters the primary dilution chamber. The dilution gasses are conditioned through a series of temperature and relative humidity determining steps. The sample gas combines with the dilution gasses in the Primary Dilution Chamber (PDC). Once the gasses have mixed, they travel through one or more Mixing/Reaction Chambers (MRCs). The MRCs allow the reaction to proceed before the combined gas streams are hit with a second quantity of dilution gas. Once the secondary dilution air is introduced, the gas stream proceeds through another series of MRCs. This gives the secondary combined gas stream (SCGS) time to complete condensing or reacting before entering the Transmissometer .

OPACITY MEASUREMENT

The Transmissometer (LDT) receives a portion of the SCGS from the final MRC. This enters the LDT and heads toward the center of the Optical Sample Cell. From the center, the SCGS heads into the condensables collection chamber where it exits the system. Any material that does condense in the LDT Optical Sample Cell falls into the condensables collection chamber and is pumped out by a peristaltic pump.

Eastern Technical Associates, PO Box 1009, Garner, NC 27529-1009. Tel: 919-878-3188; Fax: 919-872-5199.