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Eliminating fine particles from flue gas is of vital importance to improve air quality, so an outer vortex type electrocyclone (EC) designed with corona wires was built and used to trap submicron particles. Besides, a mathematical model under multi-field coupling effect was established and the charging effect rule on collection efficiency of submicron particles was revealed by comparing the performance of electrocyclone with cyclone and changing operating conditions. The results indicate that the application of charging effect greatly reduces the escape of submicron particles, making that the collection efficiency in EC is far higher than the one in cyclone. Compared to the cyclone, the ability of charging effect to promote the separation performance of EC increases with the increasing working voltage and the decreasing flue gas velocity and temperature and the trapping performance is better at a higher working voltage, lower flue gas velocity, and lower temperature. Furthermore, for outer vortex type EC, the charging effect is more prominent with the decrease of working voltage, flue gas velocity and temperature. The obtained results were evaluated to provide a reliable guide for designing an outer vortex type EC, thus greatly decreasing the number of tests and effectively reducing the research cost. A physical model of outer vortex type cyclone with corona wires was built. A theoretical model with four-field coupling interaction is established. The charging effect on collection efficiency of submicron particles is explored. Charging effect can availably improve the separation performance of cyclone. Charging effect is more prominent at lower voltage, flue velocity, and temperature. [ABSTRACT FROM AUTHOR]

Aiming at improving the trapping performance of submicron particles, the magnetic field was introduced into the outer vortex electrostatic cyclone (ESC), and the dust-removal mechanism under the action of electromagnetic field was investigated. Besides, the theoretical model was established to analyze the interaction between fluid flow field, electromagnetic field and particle dynamic field, and the influences of magnetic field on submicron particles collection efficiency at different working voltages and gas velocities were simulated and discussed. The results indicate that the introduction of magnetic field obviously enhances the ESC trapping performance for submicron particles. High working voltage and low gas velocity at a given magnetic flux density are both more favorable for trapping submicron particles, but the magnetic field effect is more obvious at high gas velocity, as well as at low working voltage. Furthermore, at the same working voltage and gas velocity, the contribution of magnetic field to collection efficiency increases with the applied magnetic flux density increased, but the increment gradually decreases, which can lay significant foundation for optimal design of submicron particles removal in ESC. [ABSTRACT FROM AUTHOR]

Understanding the various ash transformation properties is vital for improving gasification behavior and optimizing industrial operation conditions during the gasification-melting process of biomass wastes. In this work, five typical biomass wastes were selected to investigate the slag property. The ash fusion process, mineral transformation and AAEMs solidification behaviors were performed and predicted by mineral transformation analysis and thermochemical calculation. The results indicated that ash fusion process contained sintering, swelling, bubbling and melting stages, which was related to ash chemical compositions. Besides, the ash flow temperature had a linear relationship with the basic-to-acid ratio of biomass waste ashes. High SiO 2 content would lead to strong mineral crystallinity at high temperatures. The mineral transformation was also highly related to ash compositions. The complicated reactions of inorganic matters occurred when SiO 2 content lied between 50 wt% and 70 wt%. For AAEMs solidification, the alkali was prone to react simultaneously with both SiO 2 and Al 2 O 3 to form eutectoid, and the range of 35–65 wt% for SiO 2 + Al 2 O 3 contents was beneficial for alkali solidification. All the obtained data was meaningful to provide a modifying reference for the efficient and clean utilization of various biomass wastes during gasification process. • The ash melting behavior was linearly related to the base-to-acid ratio. • Four ash fusion stages were occurred during heating process. • Slags with high SiO 2 tended to show strong crystallinity at high temperatures. • The alkaline earth oxides were prone to react with SiO 2 rather than Al 2 O 3. • The alkali oxides could be solidified when SiO 2 + Al 2 O 3 content was 35–65 wt%. [ABSTRACT FROM AUTHOR]