Ejector diluter behavior assessment and dilution factor accuracy improvement

Abstract

In some applications, accurate knowledge of the dilution factor of a diluter can be crucial. Although the sample gas composition is one of the factors that influences the dilution factor of an ejector diluter, the available calibration data are usually obtained using air as sample gas. That can be a problem when the diluter is used in exhaust gas conditions, where the gas composition can differ significantly from air. Available ejector diluter models have been found unsuitable. The goal of this study was to set a method to determine the shift of dilution factor caused by sample gas composition, so the nominal or calibration value can be adjusted. Using CO₂, the method was experimentally verified with good results. In addition, the present paper also investigated the possible influence of the diluter on the particle size distribution curve of the diluted sample.

Keywords:

• Ejector diluter
• dilution factor
• aerosol measurement
• particle size distribution

Additional information

Funding

This work was supported by projects Research Center for Low-Carbon Energy Technologies CZ.02.1.01/0.0/0.0/16_019/0000753 and Optimization of HVAC systems SGS22/154/OHK2/3T/12. We gratefully acknowledge support from these grants.