The food industry is the most basic people's livelihood industry, and it continues to "evolve" with the increase of human needs. The choice of food by humans is the essential need for food. However, many times the properties of food itself cannot meet the needs of modern processing, which requires modification and processing. Without changing its essence, physical processing technology has played an important role in the food industry.
Cavitation technology is a food physical processing technology, which uses the powerful impact force generated by the collapse of cavitation bubbles to enhance the jet erosion effect. During the cavitation process, the moment when the cavitation bubble collapses will produce local extreme instantaneous high temperature and high pressure, accompanied by strong shock waves, microjets, turbulence, and high shear forces, which will change the structure of the material and change the product's structure. Processing characteristics, such as solubility, emulsification, rheology, etc. In addition to cavitation mechanism, cavitation technology also has thermal mechanism and mechanical mechanism. At present, there are two main types of common applications, one is ultrasonic technology and the other is hydraulic cavitation technology.
Ultrasonic cavitation technology
Ultrasound is an acoustic wave with a frequency greater than 20kHZ, which forms the mechanical vibration of the media particles in the medium, thereby causing the interaction of the acoustic wave and the medium. When the liquid molecular distance exceeds the critical molecular distance of the liquid, holes are formed, and the holes will be in Continuous oscillation under the action of sound waves) or collapse. When the transient cavitation bubble adiabatically shrinks to collapse, the extremely small space around the cavitation bubble can generate high temperature and high pressure, accompanied by strong shock waves, thus producing special physical and chemical effects.
Hydraulic cavitation technology
Hydraulic cavitation means that when a fluid passes through a throttle element (such as an orifice plate, venturi, etc.), due to the obstruction of the element to the fluid, the fluid flow rate becomes larger and the pressure decreases. When the fluid pressure is reduced to saturated vapor pressure or even negative pressure, due to the existence of tiny insoluble gas cores inside the fluid, the fluid vaporizes and generates a large number of cavitation bubbles. With the rapid recovery of the pressure around the liquid, the cavitation bubbles burst instantly Extinguish, so that the characteristics of related materials change. Through multiple cavitation bubble generation and destruction operations, the material can achieve the desired effect. The performance of hydraulic cavitation technology is similar to that of ultrasonic wave. Its strength is lower than that of ultrasonic wave, but its cavitation rate and energy efficiency are higher than that of ultrasonic wave.
The effects of ultrasonic cavitation and hydraulic cavitation are the same, but there are differences in application scenarios. In terms of application, ultrasonic cavitation has a wider application range, while hydraulic cavitation is only applicable to "liquid" materials. The cavitation technology has developed rapidly in recent years. Many novel methods such as light cavitation and particle cavitation are being transformed into actual productivity. It is expected to become one of the important processing methods in the food industry in the future.
Expansion: Ultrasonic Food Equipment-Ultrasonic Cake Cutting Machine in Ultrasonic Application in Food Industry.