Application principle of several characteristics of ultrasonic in ultrasonic extraction

Ultrasound refers to the sound with a frequency higher than 20kHz Generally speaking, the human ear cannot hear the sound with a frequency higher than 20kHz In fact, this is only a approximate number, because each person's listening range and ability are different It seems that ultrasound doesn't often appear in nature because people's ears can't hear the part of ultrasound This understanding is wrong For example: the lattice motion in solid materials, the collision of two metal pieces can send out ultrasound Bats are famous for their ability to travel freely in black and narrow black holes, which is based on the principle of ultrasonic ranging The application principle of ultrasonic characteristics in ultrasonic extraction 1 Mechanical effect The effect of ultrasound on the extraction solvent When the material is put into the extraction tank and the ultrasonic wave is turned on, when the ultrasonic wave propagates in the longitudinal direction, it can cause some reactions of the extracted plant cells of traditional Chinese medicine These reactions are physical changes and will not change the effective ingredients of the plant Ultrasonic vibration can cause material movement in tissue and cell Because of the tiny friction of ultrasound, it can make the cytoplasm flow, the whole cell vibrate, rotate and rub, and then produce the effect of cell friction, change the internal structure of cell, make the cell wall of plant cell become soft, and then give the effect of ultrasonic mechanical wave of appropriate time, the cell wall of plant cell will be It can break and dissolve into organic solvent 2 Thermal effect Due to the characteristics of sound absorption of biological tissue, part of the ultrasound energy injected into biological tissue will become heat energy, and make its temperature rise, at the same time, the temperature of extraction solvent will also rise When the ultrasonic intensity is fixed, the temperature will not increase with the ultrasonic time, but the change of temperature will tend to 0, basically not change From this aspect, we can also know that if the temperature required for the process of extracting a certain Chinese herbal medicine is not too high, the thermal effect of ultrasonic can be fully realized I have my own experience Take a simple ultrasonic cleaning machine, turn on the ultrasonic cleaning machine at room temperature without the heating system, and the temperature of cleaning solvent can reach after ultrasonic for a period of time To about 40 degrees This is based on the actual situation of each customer's extraction process 3 Cavitation effect When ultrasonic extraction technology is used to extract the effective components of traditional Chinese medicine, first of all, it produces unique cavitation effect in the liquid medium, that is, countless tiny bubbles with internal pressure up to thousands of atmospheric pressure are constantly generated, and the micro strong shock wave is constantly "blasted" to act on the traditional Chinese medicine, which makes the cell of traditional Chinese medicine break or deform, and under the action of cavitation bubbles generated instantaneously in the solvent It breaks down and breaks down, so that the solvent can easily penetrate into the cell and dissolve the chemical components in the solvent As the ultrasonic breaking process is a physical process, it will not change the chemical structure and properties of the extracted components.