Air classifier is a favorable equipment to control product particle size
The ultrafine air classifier can be operated in a sterile state. The average particle size of the material after the air classifier is fine, the particle size distribution is narrow, the particle shape is smooth, and it has the characteristics of high purity, high activity, and good dispersion. In addition, no heat is generated during the pulverization process, which is suitable for pulverizing low melting point and heat-sensitive substances. Therefore, the ultrafine airflow crusher is very suitable for the preparation of ultrafine drugs. According to statistics, about 25% of the international ultrafine airflow classifiers are used for Pharmaceutical Industry.
The control of the product particle size by the air classifier mainly depends on the raw material particle size, crushing pressure, feed pressure and feed speed. The logical relationship between the air classifier and these parameters is: the smaller the size of the raw material, the higher the crushing efficiency; the larger the size of the raw material, the lower the crushing efficiency. When the crushing pressure and the feed pressure are constant, reducing the feed speed will make the product finer and thicker. In the case of a certain feed rate, the particle size of the product will be finer, the crushing pressure will be reduced, and the product will become thicker. Therefore, the particle size control depends on the adjustment of the parameters in the ultrafine air classifier process to achieve different grinding fineness. Before smashing, it is necessary to determine the relationship between the feed speed and the pressure and then determine the appropriate smashing parameters to meet the customer’s particle size requirements. The particle size of the product needs to be checked by a particle size detector to check the fineness and distribution range. In addition, if the measurement with the electron microscope can be more accurate, of course, it can also be compared with the internationally famous particle size detector.
The air classifier is a relatively precise machine. In the process of daily use and maintenance, some details still need the attention of the operator. In order to improve the classification efficiency of the ultra-fine air classifier, it is necessary to check whether the raw materials meet the requirements before production. Mix foreign matter into the raw material. During the production process, a certain amount of material must be kept in the grinding cavity of the air classifier. Under the condition of constant pulverizing gas flow, there are more materials in the grinding chamber, the current of the classifier is larger, and the materials in the grinding chamber are less, and the current of the classifier is smaller. In addition, the feeding speed must be uniform and stable, not too fast or too slow. If the feeding speed is too fast, the equipment will be overloaded.
The equipment should be maintained regularly, and the air supply pressure should be checked frequently to meet the pressure required for crushing, as well as the classification motor of the airflow classifier. After the equipment runs for 3000 hours, or for long-term shutdown and long-term storage and reuse, please clean the nozzles and grinding chambers. The materials on the inner wall should be cleaned up in time to prevent the classification effect of the air classifier from being affected.