20Khz Ultrasonic Liquid Processor with Explosion Proof for CLEANING CHEMICALS Defoaming

The degassing process of ultrasonic probe sonicator

In general conditions, there is a certain number of dissolved gas in the liquid and form a state of equilibrium level, the concentration of gas may be affected by many factors including atmospheric pressure, agitating strength and temperature. Ultrasonic degassing can break the equilibrium state and reduce the gas concentration in the solution.

Via the oscillation generated by radiating surface of sonicator, the ultrasound wave is propagated into the fluid and generates a large number of small vacuum bubbles which are widely distributed in the liquid. Due to the increase in bubble volume, the pressure within the bubble is gradually decreased, and the dissolved gas tend to diffuse into the inflated bubble from surrounding solution until the cavitation bubble has reached its limit. Conversely, when the bubble begin to shrinking, the gas within bubble will diffuse back into the solution. Because the time is very short, there are still a lot of gases rise to the surface of the liquid together with bubbles. The whole process occurs as a repeated cycle and ultimately the degassing work is accomplished successfully.

On the other hand, the rapid process of sonication greatly reduces the contact time between the small bubbles and the fluid level. That means it's hard for gas to re-dissolve from the vacuum bubble to the fluid. This has important significance to degassing result especially for the fluids with higher viscosity e.g. epoxy resin or silicone oil.

The nodes attract matter and so the foam bubbles which implode as a result of the compression forces generated.

Parameter

Factors affecting the ultrasonic degassing effect

1) The impact of sonicating conditions

Increased temperature helps to reduce the viscosity of the fluid medium, and further to improve the cavitation effect for ultrasonic degassing, yet the higher temperature may lead to a higher vapor pressure which can make up the gas concentration. After all things considered, we should find a balance to determine the optimal temperature for sonication. Of course, if the solution isn't exposed to any gas i.e. a gas pump is applied to form the vacuum above the liquid surface, heating the solution is a good method.

2) Influence on design of ultrasonic sonicator and container

First, to prevent the solution getting turbulent by controlling the amplitude of sonicator and agitation. The probe of ultrasonic sonicator with larger surface is beneficial to generate cavitation bubbles in a more extensive area. It means that the more gases can be trapped into the bubbles to obtain a better degassing effect. Other than that, in order to prevent the re-dissolving of gases from bubbles to the solution, the shallow tank or container will be conducive to reduce the time to the liquid surface.