4.3 Influences of ultrasound freque

4.3 Influences of ultrasound frequency
The desalting and dewatering results were also
influenced by the ultrasonic frequency. The experiment
conditions in this study were oil flow velocity 20
L·h－1, water flow velocity 0.9 L·h－1, demulsifier dosage
30 μg·g－1, differential pressure of mixing 0.4 MPa,
electric intensity 1.2 kV·cm－1, and ultrasonic power
150 W.
The influences of different ultrasonic frequencies
were studied on different temperatures, as shown in
Fig. 4. The results of using the 10-kHz device were
better than that of using the 20 kHz on the same conditions.
As reported [11], there was an optimal frequency,
which matched to a given diameter dispersion
of small particles. The experiments showed that to
treat the LU-NING pipeline oil, the 10-kHz device
was more suitable than the 20-kHz device.