Study on the fast elimination of smoke particle based on electro-acoustic coupling agglomeration technology

Fire smoke,which consists large amounts of fine particles,is considered as the fatal factor in fires.In this study,a fast smoke particle elimination method based on electro-acoustic coupling agglomeration technology is proposed.First,the experimental results show that the electro-acoustic coupling agglomeration has higher smoke elimination efficiency compared to single-field.The smoke transmission is much less than 80%after 30s of single acoustic or electric field action,while the coupled field reaches 90%.Then,the effects of acoustic frequency,sound pressure level and voltage on the smoke elimination characteristics are discussed.It is found that the optimal acoustic frequency is 1.5kHz.While as the sound pressure level and voltage increase,the elimination efficiency first increases and then tends to stabilize,the critical values of the sound pressure level and voltage are 135 dB and 7kV.This indicates that there is an optimal combination of the three variables.Finally,through the theoretical analysis of particle movement and the micro-morphology of agglomerates,the particle agglomeration mechanism under the electro-acoustic coupling is analyzed.This study provides a new idea for the fast elimination of fire smoke particle.

Characterization of particle size distribution of mainstream cigarette smoke generated by smoking machine with an electrical low pressure impactor

Cigarette smoking is a particle-related exposure. Studying the characteristics of the particle size distribution of cigarette smoke can aid in providing knowledge of smoke aerosol attributes. We used an electrical low pressure impactor （ELPI） to measure the particle size distribution of mainstream cigarette smoke generated by a smoking machine and provided a continuum of particle sizes of cigarette smoke from a whole cigarette. The results showed that the aerodynamic diameters （D, geometric mean of a channel） of particles ranged from 0.021 to 1.956 ~m, and the number concentrations were on the order of 105-109 cm-3 for different sizes of particles. The particle number of the size category below 0.1 p,m approximated that of the category 0.1-2.0 Ixm, and the particles in the size category of 0.1-2.0 μm contributed extremely heavily to total particulate mass. In addition, the results with small samples indicated that the tar yields normalized per milligram of nicotine showed an approximately linear increase with increasing concentration of total particles.