Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing 210096, China.
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy & Environment, Southeast University, Nanjing 210096, China; Department of Mechanical and Aerospace Engineering, SAPIENZA University of Rome, Via Eudossiana, 18-00184 Rome, Italy.
J Environ Sci (China). 2018 May;67:161-170. doi: 10.1016/j.jes.2017.08.021. Epub 2017 Sep 1.
Diesel exhaust aerosols (DEAs) can absorb and accumulate toxic metal particulates and bacteria suspended in the atmospheric environment, which impact human health and the environment. The use of acoustic standing waves (ASWs) to aggregate DEA is currently considered to be an efficient particle removal method; however, study of the effect of different temperatures on the acoustic aggregation process is scarce. To explore the method and technology to regulate and optimize the aerosol aggregation process through temperature tuning, an acoustic apparatus integrated with a temperature regulation function was constructed. Using this apparatus, the effect of different characteristic temperatures (CTs) on the aerosol aggregation process was investigated experimentally in the ASW environment. Under constant conditions of acoustic frequency 1.286kHz, voltage amplitude 17V and input electric power 16.7W, the study concentrated on temperature effects on the aggregation process in the CT range of 58-72°C. The DEA opacity was used. The results demonstrate that the aggregation process is quite sensitive to the CT, and that the optimal DEA aggregation can be achieved at 66°C. The aggregated particles of 68.17μm are composed of small nanoparticles of 13.34-62.15nm. At CTs higher and lower than 66°C, the apparatus in non-resonance mode reduces the DEA aggregation level. For other instruments, the method for obtaining the optimum temperature for acoustic agglomeration is universal. This preliminary demonstration shows that the use of acoustic technology to regulate the aerosol aggregation process through tuning the operating temperature is feasible and convenient.
柴油机排气气溶胶（DEAs）可以吸收和积累大气环境中悬浮的有毒金属颗粒和细菌，从而影响人类健康和环境。目前，利用声驻波（ASWs）来聚集 DEA 被认为是一种有效的颗粒去除方法；然而，关于不同温度对声聚集过程影响的研究还很少。为了探索通过温度调节来调控和优化气溶胶聚集过程的方法和技术，构建了一个集成温度调节功能的声装置。使用该装置，在 ASW 环境中实验研究了不同特征温度（CT）对气溶胶聚集过程的影响。在声频率 1.286kHz、电压幅度 17V 和输入功率 16.7W 恒定条件下，研究集中在 CT 范围为 58-72°C 时对聚集过程的温度影响。使用 DEA 不透明度。结果表明，聚集过程对 CT 非常敏感，在 66°C 时可以实现最佳的 DEA 聚集。68.17μm 的聚集颗粒由 13.34-62.15nm 的小纳米颗粒组成。在高于和低于 66°C 的 CT 下，该装置处于非共振模式，降低了 DEA 聚集水平。对于其他仪器，获得最佳声团聚温度的方法是通用的。初步论证表明，利用声技术通过调节工作温度来调节气溶胶聚集过程是可行和方便的。
