The most prominent and widely known effect of power ultrasound in liquids is the dispersion effect. The dispersion of ultrasonic waves in liquids mainly depends on the ultrasonic cavitation of liquids.
The use of ultrasonic dispersion can eliminate the need to use emulsifiers. In many cases, ultrasonic emulsification can obtain particles below 1 μm. The formation of this emulsion is mainly due to the strong ultrasonic cavitation near the dispersion tool. The chemical agent can disperse the paraffin wax in water and the diameter of the dispersion is less than 1μm.
The holding point of ultrasonic dispersion is usually small vibration and high acceleration. Ultrasonic dispersion devices have been widely used in the fields of food, fuel, new materials, chemicals, coatings, etc.
Principles of dispersion
1. Ultrasonic generator: its efficiency is as high as 90%, and it is small in size and light in weight; (also called ultrasonic drive power).
Ultrasonic dispersion equipment
2. Ultrasonic aid system, in order to obtain high power, the common vibration frequency is selected at about 15kHz, the ultrasonic generator and resonance system form an automatic frequency tracking system; (ultrasonic vibrator composed of ultrasonic transducer and ultrasonic horn ).
3. Ultrasonic dispersion tool; (the ultrasonic tool head is connected to the vibrator).
4. Dispersion container. The working principle of the homogenizer, when the ultrasonic generator outputs high-frequency voltage force, the ultrasonic booster is amplified by the mechanical vibrating cap by the vibrator, and then under the action of the dispersing tool, it performs a strong micro-processing in the container.
Two factors determine the effect of dispersion: ultrasonic impact force; ultrasonic radiation time.
The flow of the treatment liquid is Q, the gap is c, and the area of the plate in the opposite direction is S. The average time t required for a specific particle in the treatment liquid to pass through this space is: t=c*S/Q. To improve the ultrasonic dispersion effect, it is necessary to control the average pressure p of the treatment liquid, the gap c, and the ultrasonic radiation time t(s).
Application scope edit
Principle of Ultrasonic Dispersion
Ultrasonic dispersion has a wide range of applications in many fields: such as food, cosmetics, medicine, chemistry, etc. The application of ultrasound in food dispersion can be roughly divided into three situations: liquid-liquid dispersion (emulsion), solid-liquid dispersion (suspension), and gas-liquid dispersion. 
Solid-liquid dispersion (suspension): such as powder emulsion dispersion.
Gas-liquid dispersion: For example, the production of carbonated beverage water can be improved by the CO2 absorption method to improve stability.
Liquid-liquid dispersion (emulsion): e.g. emulsification of ghee to make lactose; dispersion of raw materials when making sauces, etc.
Ultrasonic dispersion can also be used for the preparation of nanomaterials; for the detection and analysis of food samples, such as the use of ultrasonic dispersion liquid phase micro-extraction technology