Abstract: Abstract： A smallscaled acoustic agglomeration test bench was built. Chosing the high intensity ultrasound as the sound source, selecting the aerosol with large amount of ultrafine particles which were produced by combustion as research objects, and using SMPS to measure the number of particles, the influence of initial particles parameters and the acoustic agglomeration periods on the agglomeration efficiency was studied. The results show that the acoustic wave of 20 kHz has some effect on the particles whose diameter range from 10 nm to 487 nm. Within the measuring range, a higher acoustic agglomeration efficiency can be obtained if the acoustic agglomeration acting period is longer. Besides, 18 seconds is an ideal duration under the test condition. If the initial particle diameter in peak concentrations is bigger, the acoustic agglomeration efficiency will be improved with a maximum of 82.4%.The acoustic agglomeration efficiency also has a positive correlation with initial particle concentration. The particles with a diameter in peak concentration often have a better agglomeration efficiency.

Key words: Key words： ultrafine particle, acoustic agglomeration, particle concentration