Ultrasonic degassing is the process of removing dissolved gas and/or entrained small bubbles from liquid. Transformer oil, lotion and suspension products, engine oil, etc. from various liquids, including water, candle wax, polymers, epoxy resins, silicone oil, adhesives, coatings, beverages, inks, gases removed from coatings. Degassing can significantly improve the quality of the final product (reduce defects, improve aesthetics, etc.). Unlike vacuum degassing with intermittent method, ultrasonic degassing can be carried out in a continuous flow mode.
Working principle Ultrasonic wave propagates from acoustic transmitter to liquid medium, producing alternating positive and negative pressure phases. In the negative pressure (dilution) stage, ultrasound with enough high strength can overcome the adhesion between molecules and produce a large number of near vacuum microbubbles in the liquid. Bubbles absorb more gas when they expand and release it when they contract, so their volume increases rapidly. This process is called "directional" or "rectification" diffusion. Due to the uniform distribution of bubbles in the liquid and large total surface area in the process of gas-phase acoustic cavitation, the migration speed of dissolved gas in the entire affected liquid volume is fast and uniform. The result is the formation of a large number of oscillating bubbles, which contain gases previously dissolved in the liquid medium. When bubbles beat in the ultrasonic field, they will accelerate and merge with each other to form larger bubbles. This process proceeds very quickly until the bubble reaches enough buoyancy to float on the liquid and release the previously trapped gas into the environment.

Ultrasonic degassing is caused by cavitation. The ultrasonic wave passing through the liquid makes it continuously compress and expand. High intensity ultrasound provides the energy needed to disperse the liquid phase. When the maximum pressure is reached, liquid fracture occurs at the point where the cohesion is weak. After this fracture, overpressure occurred at the point where the fracture occurred and some cavities were found. In these cavities, the gas dissolved in liquid explodes in the form of bubbles after a short time.