In recent years, with the rapid development of my country's traditional Chinese medicine industry, the machinery and equipment industry related to the deep processing of the traditional Chinese medicine industry has also ushered in more development opportunities. Among them, in the drug production process, the particle size is very important for the bioavailability of the drug, so crushing is a very critical link. Due to the low crushing temperature, short production cycle, high powder collection rate, uniform and fine particle size distribution, the traditional Chinese medicine jet mill has become a powerful assistant in the pharmaceutical crushing process. Let us follow the editor of the jet mill manufacturer to see what factors affect the jet mill.

It is understood that the jet mill, also known as jet mill, jet mill or energy flow mill, is a kind of ultrafine pulverization of solid materials using the energy of high-speed airflow (300-500m/s) or superheated steam (300-400℃) Equipment. As one of the commonly used ultra-fine grinding equipment, jet mills are widely used in ultra-fine grinding and dispersing forming of ultra-hard materials such as chemical materials, medicines and foods, and metal powders.

Some customers say that the jet mill has a wide range of crushing particle sizes and is easy to operate. However, in the crushing process, the crushing effect is usually different. What is going on? The technical staff of the jet mill manufacturer said that the crushing effect of the jet mill is mainly affected by the following factors: gas-solid ratio, temperature and pressure of the working fluid.

Gas-solid ratio

It is understandable that the gas-solid ratio of the Chinese medicine jet mill is an important technical parameter and also an important index in the crushing process. If the gas-solid ratio is too small, the kinetic energy of the air flow will be insufficient, which will affect the fineness of the product. However, if the gas-solid ratio is too high, not only energy will be wasted, but the dispersion properties of certain pigments will also deteriorate.

Therefore, technicians suggest that when the user uses superheated steam as the working fluid, when the user uses superheated steam as the working fluid, the gas-solid ratio is usually controlled at 2:4:1. The gas-solid ratio is usually controlled after surface treatment The material is usually controlled at 1:1 in a ratio of 2:4:1.

Working fluid temperature

Technicians say that when the temperature of the working fluid is too high, the flow of gas will increase. Taking air as an example, the critical velocity at room temperature is 320m/s. When the temperature rises to 480℃, the critical speed can be increased to 500m/s, that is, the kinetic energy increases by 150%. Therefore, increasing the temperature of the working fluid is conducive to improving the performance of the Chinese medicine jet mill.

In addition, when the titanium powder is pulverized, the temperature of the superheated steam is usually about 300 to 400°C. Technicians say that during the pulverization and calcination process, the temperature is usually higher, and when the surface-treated material is pulverized, the temperature is lower. Some surface treatment agents, especially organic surface treatment agents, are not resistant to high temperatures, so it is only necessary to overheat 100°C on the basis of the original steam temperature.

Working fluid pressure

The pressure of the working fluid is the main parameter that produces the jet flow rate, and it is also the main parameter that affects the fineness of pulverization.

Generally speaking, the higher the working fluid pressure and the faster the speed, the greater the kinetic energy. So, what pressure should be selected when crushing? The technician said that it mainly depends on the fragility and fineness requirements of the material. For example, when superheated steam is used to pulverize titanium powder, the vapor pressure is usually 0.8-1.7 MPa, while the pulverized and calcined materials are usually higher, and the pulverized surface-treated materials can be lower.