4.8 Running results under the optim

4.8 Running results under the optimized conditions
The conditions of the ultrasonic-electric united
process to treat the LU-NING piping oil were discussed
above.
An experiment of the devices had also been carried
out on the best conditions. The temperature was
about 83-89°C. The relationships of water content and
salt content vs. running time at the best conditions
were shown in Fig. 9 and Fig. 10. The original salt
content of the crude oil was 67.5 mg·L－1. After 40 h,
the salt content in the oil was steady at 4.0-5.5 mg·L－1.
The best desalting result was 3.97 mg·L－1. Its desalting
ratio was over 90%. The water content after treatment was usually below 0.30%. The data from the
refinery of YPC was shown in Fig. 11. When the
original salt content was as high as 40 mg·L－1, the
final salt content was still above 10 mg·L－1 after
two-stage electric desalting treatment at 140°C. The
comparison of those two processes showed that the
ultrasonic-electric united process was better; especially
treating the high salts containing crude oil. Such
a novel technology could be considered to ensure the
salt content of crude oil to meet the need of refinery.