Experimental study on production and emission characteristics of PM2.5 from industrial fluidized bed boilers

• Main Authors: Zhang Songsong, Du Qian, Qi Guoli
• Format: Article
• Language: English
• Published: VINCA Institute of Nuclear Sciences 2020-01-01
• Series: Thermal Science
• Subjects: industrial fluidized bed boiler; pm2.5; concentration; dustremoval efficiency; physical and chemical properties
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-9836/2020/0354-98362000001Z.pdf

Particle size distributions, concentrations, morphological characteristics, and elemental compositions of eight fluidized bed boilers with different capacities and different dust collectors were determined experimentally. The PM2.5 particle concentration and mass concentration were monitored in real-time before and after the boiler dust collector by electric low pressure impactor, and the physical and chemical properties of PM2.5 were analyzed by membrane sampling. We found that the PM2.5 particle concentration produced by industrial fluidized bed boilers displayed bimodal distributions, peaking at 0.2 μm and 0.76 μm, the formed mechanism of these two parts particles is vaporization-condensation of mineral matter and residual ash particles and the adsorbent wear or tear. Mass concentration exhibits a single peak characteristic with a peak at 0.12 μm. The removal efficiency for PM2.5 of dust collectors varies with different dust removal mechanisms. The electrostatic precipitator and bag filter have high dust removal efficiency, and the water film dust collector has low dust removal efficiency. The normal operation of the bag filter has a great influence on the dust removal efficiency. The physical and chemical properties of PM2.5 showed that the single-particle morphology was mainly composed of irregular particles, containing a small amount of solid spherical particles and more agglomerates. The content of Si and Al in PM2.5 elemental analysis is the highest, which decreases after a dust collector. Some fluidized bed boilers use desulfurization in the furnace, which has great influence on the mass concentration of Ca and S elements, and the lowest Hg content in trace elements, about a few ppm.