Investigation on the relationship of droplet atomization performance and fine particle abatement during the chemical agglomeration process

Abstract

Two kinds of polymer solutions with different chemical properties were adopt to conduct the chemical agglomeration experiment via the simulated coal-fired facility, and the atomization performances of sesbania gum (SBG) and styrene butadiene emulsion (SBE) solutions were also investigated using a Phase-Doppler anemometry (PDA) system. The results revealed that the abatement of fly ash fine particles was obviously influenced by the atomization performance of chemical agglomeration solution, which were mainly depended on the mass concentration of agglomerant and the air pressure of nozzle. Owing to the viscosity of SBG solution was higher than that of SBE solution at the same mass concentration, the atomization performances of SBG was deteriorated faster leading to the removal performance of SBE on fine particles was better than that of SBG. When the mass concentration was 0.5%, the median diameter (D50) of SBG solution was 24.032 μm, and removal efficiency on fine particles was 28.44%. Whereas for SBE, the removal efficiency was up to 33.19% with a D50 of droplets was 16.918 μm. Besides, the increasing of nozzle air pressure was beneficial to improve the atomization of chemical agglomeration solution, resulting in the reduction of fine particles number concentration after chemical agglomeration. According to the analysis of SEM, EDS and XPS spectrum, the results indicated that the fine particles could be adhered together to form newly larger aggregate by chemical force.