Review and prospect of fog elimination technology based on acoustic condensation

Abstract This paper summarizes the traditional artificial fog elimination technology and the principle and mechanism of acoustic condensation theory, reviews the simulation experiment research and application of acoustic condensation fog elimination technology. Compared with traditional fog elimination technology, sum up the advantages and disadvantages of acoustic condensation fog elimination technology. Put forward the existing problems and future research direction of acoustic condensation fog elimination field.</jats:p

Numerical Simulation of Condensation of Natural Fog Aerosol under Acoustic Wave Action

Abstract Acoustic condensation has proved its excellent performance in the dissipation of suspended fine particles. It is also promising for artificial fog dissipation, but the current research is still lacking. This paper sums up the mathematical model of acoustic condensation. Considering the physical properties of droplets, the improved root mean square (IRMS) acoustic condensation kernel function is proposed, which is compared with the analytic solution to verify the correctness. Through the method of numerical simulation, different condensation effects of the different condensation mechanisms are compared. Study the effect of acoustic frequency, sound pressure level and initial concentration on the condensation of natural fog aerosol under the action of sound waves. The results show that the droplet condensation efficiency can be improved by acoustic effect significantly; The effect of acoustic frequency on droplet condensation is nonlinear, and there is an optimal frequency of 600 Hz. Besides, high-frequency sound wave has a better effect on small particles’ condensation, while low-frequency sound wave has a better effect on large particles’ condensation. The sound pressure level and initial particle concentration is positively correlated with the condensation efficiency, and there is a critical particle size. After the acoustic condensation, the concentration of particles larger than the critical particle size increases, and decreases conversely

Experimental study on acoustic condensation fog elimination in traveling wave tube

Abstract Acoustic condensation artificial fog elimination has the advantages of wide application range, good economy, flexible and controllable operation area, and does not affect traffic operation. The characteristics of the fog, the frequency and intensity of the acting sound waves have an important influence on the effect of condensation and fog elimination. This paper studies the influence of the frequency of fog on the microscopic particle size distribution and the change of light transmission in the process of fog elimination from both theoretical and experimental aspects. The research results show that for natural fog conditions with low concentration, the time of pure sound wave action takes several minutes to tens of minutes. Under the condition of high-concentration artificial fog, the anti-fog time can be shortened to tens of seconds. Simulations and experiments have both confirmed that sound waves can significantly promote fog elimination, and there is an optimal frequency between 200Hz-700Hz.</jats:p

Experimental verification of fine particle emission reduction based on acoustic agglomeration for steel sintering flue gas

Abstract The sintering flue gas in steel production has the characteristics of large discharge capacity, fine size, high temperature, corrosion and fluctuation of working conditions, and is the primary control object of PM2.5 emission source. Traditional dust removal technologies and equipment are difficult to achieve efficient collection of fine particles. In order to quantitatively study the effect and regularity of high intensity sound waves on fine particles, the online acoustic agglomeration test system was built by using high-power pneumatic source and wave tube with abrupt section. The high intensity standing wave field of 140 to 150 dB was generated in the wide frequency range between 50 Hz and 2 kHz by the acoustic resonance synthesis, and interference from compressed airflow was avoided by the acoustic-flow separation module. Variation of the sintered flue gas PSD was obtained under different sound intensities and frequencies. Data analysis shows that the high concentration condition can greatly reduce the operation time and energy consumption. Under the action of high intensity acoustic waves with a fundamental sound pressure level of 87.3-161.8dB and duration of 3s, the measured PM2.5 removal efficiency is 16%-92%, and the optimal frequency is near 800Hz. This paper verifies the feasibility of acoustic agglomeration (AA) in the treatment of sintering flue gas, and provides a theoretical reference and technical basis for the development of PM2.5 real-time emission control device for steel production.</jats:p

Study on the relationship of working memory, central executive function and general fluid intelligence(工作记忆、中央执行功能与流体智力的关系分析)

探讨工作记忆、中央执行功能子成分与流体智力的关系.以秦巴山区18~40岁健康成人为研究对象，通过对中央执行功能子成分、工作记忆广度以及流体智力的测量，分析了各变量之间的关系，并进一步探讨了中央执行功能各子成分的可分离性.得到(1)工作记忆中的中央执行功能具有可分离性；(2)工作记忆广度与瑞文测验成绩之间的显著相关是刷新功能的作用；(3)相对于抑制功能和转换功能，刷新功能对流体智力具有更强的预测效应和解释力