Siris™

Real Time Soot Size and Concentration Measurement for Diesel Engines and Gas Turbines

Siris™ measures real-time diesel and gas turbine engine soot emissions. This new instrument, invented and developed by Process Metrix, measures total soot particle (agglomerate) mass, mean size, and primary particle number...all at 10 Hz data rates.

 

Siris

Siris™ is a new instrument that measures real-time diesel engine and gas turbine soot emissions. Invented and developed by Process Metrix under contract to the U.S. Government, this commercial-ready system has the capability to provide "gravimetric" measurements using optical diagnostics in real time. Our goal is not to replace conventional filter-based measurement technology, but to provide time-resolved measurements of soot emissions. This time resolution provides greater insight into soot formation mechanisms as a function of engine operating parameters; critical information necessary to optimize performance for minimum emission.

Siris™ provides the following output data at 10 Hz data rates:

  • Total mass,
  • Soot agglomerate mean size,
  • Primary particle number,
  • Surface area.

Siris™ uses laser light scattering collected at two angles to measure and calculate the total particle (agglomerate) mass and size using a fundamental scattering theory (patent pending) based on the soot properties of the spherical primary soot particles that comprise the agglomerates. Once the mass and size are known, the primary particle number and surface area are computed from these parameters over a wide dynamic range, given as follows:

  • Measurable particle mass concentration: 0.001–1000 mg/m3,
  • Measurable particle sizes range: 50–500 nm
Most importantly, Siris™ has been carefully evaluated against gravimetic sampling in a real diesel engine test configuration. Results (at left) incorporate literature values for carbon refractive index and density, which are independent of engine operating conditions, to calculate mass emissions from the measured scattering signals. The graph clearly shows quantitative correlation between the real-time Siris™ measurements, and the filter-based data.

The time-resolution capability of the Siris system is illustrated in the data shown below. These data represent optical measurements of soot particulate over an engine driving cycle. Measurements were made on a 1-second update interval. Cumulative mass is illustrated as well – the ending value correlating with the gravimetic filter analysis as shown above.


Siris™ is available in three different configurations:

  • Stand-alone –The optical head alone, with configuration and readout software.
  • Valve Control – The stand alone system packaged in an enclosure with appropriate valving for calibration and process gas flow control,
  • Process Ready – Process Metrix has partnered with Sierra Instruments to integrate Siris™ into Soot-Trak™, Sierra's real time engine soot mass emisisons system. Soot-Trak is completely integrated with Sierra's world renowned Model BG-3 Partial Flow Sampling System (PFSS). The combination yields real-time measurements of soot mass, particle size, primary particle surface area and number in parellel with standard EPA gravimetric filter sampling also provided by the BG-3.

For more information on the Siris™ system contact:

Donald Holve, Ph.D
dholve@processmetrix.com
voice:(925) 460-0385 x116

For information on the Siris™ System integrated with Sierra Instruments BG-3 Particulate Sampling system contact:

Del Pier
dpier-sierraemissions@comcast.net
voice: (517) 575-7485