Ultrasonic degreasing is to use the mechanical energy of ultrasonic oscillation to act on the degreasing liquid, and alternately generate instantaneous positive pressure and instantaneous negative pressure periodically. A large number of cavities are generated in the negative pressure half-cycle solution, and the vapor and dissolved gas become bubbles, and then in the positive pressure half-cycle, the instantaneous strong pressure causes the bubbles to be compressed and burst, generating tens of thousands of shock waves , to generate intense agitation for the solution and strongly impact the surface of the parts , thus accelerating the degreasing process and effectively removing the oil stains in the deep recesses and pores on the surface of the parts.
Ultrasound can be applied to solvent degreasing, chemical degreasing and electrochemical degreasing, and can also be used in pickling and other occasions to achieve degreasing, rust removal, and film removal (dust, scum, and dirty film) in one step or in steps. The concentration and temperature of ultrasonic Because the concentration and temperature are too high, it will hinder the propagation of ultrasonic waves and reduce the degreasing ability. The use of ultrasound reduces the temperature and concentration of the degreasing fluid, saving energy and protecting the base metal from corrosion. The composition and ratio of the degreasing liquid should be reasonably selected, and the appropriate parameters such as the frequency and intensity of ultrasonic oscillation should be selected.
Ultrasonic degreasing is more effective for parts . Generally, the ultrasonic frequency used for degreasing is about 30Hz. For small complex parts, ultrasonic waves with high frequency and low amplitude can be used , and for parts with large surfaces, ultrasonic waves with lower frequencies can be used.
The ultrasonic cleaning device consists of a vibrating plate and an ultrasonic generator, as shown in the figure. There are standard models on the market . If the standard models are not suitable for special working environments, submersible ultrasonic devices can also be used. The shock plate and the ultrasonic generator of the submersible ultrasonic device adopt a split structure, and the arrangement is flexible . According to the needs of the ultrasonic radiation surface, the vibration plate can be arranged on the bottom surface, side surface or top surface of the cleaning tank. In order to get a good degreasing effect on the depression and the back part of the part, it is better to rotate so that all parts can be radiated by ultrasonic waves.
