| Gas-solid two-phase flow is complicated but important, and it is difficult to accurately measure the solid concentration and particle fineness. While the two-phase flow of the swirl burner outlet related to the stability of the flame, the generation of air pollutants NOx, and problems of water walls slagging, it is essential to study the changing gas-solid flow field. Electrostatic principle is applied in this paper, and electrostatic-grid method is proposed and designed firstly, the research object is extended from gas-solid two-phase flow in the tube to large space by electrostatic method. Through summarizing the theories and methods of the electrostatic measurement in tubes, we find out that the particle velocity measurement technique is close to maturity, but cannot acquire an accurate measurement of absolute concentration.The content of this paper mostly touch upon these following aspects:First, according to experimental needs, electrostatic-grid is designed, which can achieve the signals’capturing, filtering, amplification and data collection. This method is proved feasibility when measuring the relative concentration according to a feeding system.Second, particle distribution and dispersion characteristics in the two-phase flow of the swirl burner outlet are researched by the electrostatic-grid method, we find out that, the difference of concentration is distinct under different cases and different cross-sections, and the trend in accordance with the basic law. This is an effective method for the study of the burner concentration separation technology and staged combustion separation technology.Finally, concentration measurements by electrostatic-grid method is compared with optical wave method, there is same trend of concentration with a little difference. Changing different solid flow rate could find that, in the large space of the flow field, the average voltage signal of electrostatic-grid and the particle mass flow rate is an approximately linear relationship. |
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